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Year:
2013
Edition:
4
Publisher:
Churchill Livingstone Elsevier
Language:
english
Pages:
321
ISBN 10:
070204671X
ISBN 13:
9780702052453
File:
PDF, 20.95 MB
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Preface

150

ECG
Problems

For Elsevier
Content Strategist: Laurence Hunter
Content Development Specialist: Helen Leng
Project Manager: Louisa Talbott
Designer/Design Direction: Mark Rogers
Illustration Manager: Jennifer Rose
Illustrators: Helius and Chartwell Illustrators

150

ECG
Problems

FOURTH EDITION

John R. Hampton
DM MA DPhil FRCP FFPM FESC
Emeritus Professor of Cardiology,
University of Nottingham, UK

EDINBURGH LONDON NEW YORK OXFORD

PHILADELPHIA ST LOUIS

SYDNEY

TORONTO

2013

Notices
Knowledge and best practice in this field are constantly changing. As
new research and experience broaden our understanding, changes in
research methods, professional practices, or medical treatment may
become necessary.

© 2013 Elsevier Ltd. All rights reserved.
No part of this publication may be reproduced or transmitted in any
form or by any means, electronic or mechanical, including
photocopying, recording, or any information storage and retrieval
system, without permission in writing from the publisher. Details on
how to seek permission, further information about the Publisher’s
permissions policies and our arrangements with organizations such as
the Copyright Clearance Center and the Copyright Licensing Agency,
can be found at our website: www.elsevier.com/permissions.
This book and the individual contributions contained in it are
protected under copyright by the publisher (other than as may be
noted herein).
First edition 1997
Second edition 2003

Third edition 2008
Fourth edition 2013

ISBN 978-0-7020-4645-2
International ISBN 978-0-7020-4671-1
e-book ISBN 978-0-7020-5245-3
British Library Cataloguing in Publication Data
A catalogue record for this book is available from the British Library
Library of Congress Cataloging in Publication Data
A catalog record for this book is available from the Library of
Congress

Practitioners and researchers must always rely on their own
experience and knowledge in evaluating and using any information,
methods, compounds, or experiments described herein. In using s; uch
information or methods they should be mindful of their own safety
and the safety of others, including parties for whom they have a
professional responsibility.
With respect to any drug or pharmaceutical products identified,
readers are advised to check the most current information provided
(i) on procedures featured or (ii) by the manufacturer of each product
to be administered, to verify the recommended dose or formula, the
method and duration of administration, and contraindications. It is
the responsibility of practitioners, relying on their own experience
and knowledge of their patients, to make diagnoses, to determine
dosages and the best treatment for each individual patient, and to
take all appropriate safety precautions.
To the fullest extent of the law, neither the publisher nor the authors,
contributors, or editors, assume any liability for any injury and/or
damage to persons or property as a matter of products liability,
negligence or otherwise, or from any use or operation of any
methods, products, instructions, or ideas contained in the material
herein.

The
publisher’s
policy is to use
paper manufactured
from sustainable forests

Printed in China

Preface

Learning about ECG interpretation from books such
as The ECG Made Easy or The ECG in Practice is fine
as far as it goes, but it never goes far enough. As with
most of medicine there is no substitute for experience,
and to make the best use of the ECG there is no substitute for reviewing large numbers of them. ECGs
need to be interpreted in the context of the patient
from whom they were recorded. You need to learn to
appreciate the variations of normality and of the patterns associated with different diseases, and to think
about how the ECG can help patient management.
Although no book can be a substitute for practical
experience, 150 ECG Problems goes a stage nearer
the clinical world than books that simply aim to teach
ECG interpretation. It presents 150 clinical problems
in the shape of simple case histories, together with
the relevant ECG. It then invites the reader to interpret the ECG in the light of the clinical evidence
provided, and to decide on a course of action before
looking at the answer. Having seen the answers, the
reader may feel the need for more information, so
each one is cross-referenced to The ECG Made Easy
and/or The ECG in Practice.

The ECGs in 150 ECG Problems range from the
simple to the complex. About one-third of the problems are of a standard that a medical student should
be able to cope with, and should be answered correctly by anyone who has read The ECG Made Easy.
A junior doctor, specialist nurse or paramedic should
get another third right, if they have read The ECG in
Practice. The remainder should challenge the MRCP
candidate. As a very rough guide to the level of difficulty of each problem, each answer is graded using
stars (see the summary box of each answer): one star
represents the easiest records, and three stars the most
difficult.
The ECGs are arranged in random order, not in
order of difficulty, to maintain the reader’s interest.
Readers are invited to attempt their own interpretation before looking at the star rating – after all, in a
real-life situation one never knows which patient will
be easy and which will be difficult to diagnose or
treat.
In this fourth edition there are many new ECGs,
mainly to provide examples that reproduce more
clearly. However, to maintain the “real world”

v

Preface
approach, some technically poor records have deliberately been included. The balance between easy,
moderately difficult and very difficult records has
been maintained.
I am extremely grateful to Alison Gale, my copyeditor, and to Rich Cutler of Helius. Their patience,

understanding and attention to detail made the preparation of this new edition an easy and satisfying
experience for me.

Cross-references
The symbols

vi

indicate cross-references to useful information in the books The ECG Made
Easy, 8th edn, and The ECG in Practice, 6th edn, respectively.

John Hampton
Nottingham, 2013

Introduction: making
the most of the ECG

Recording and reporting an ECG should never be an
end in itself. The ECG is a basic and valuable tool in
the investigation of cardiac problems, and it can be
helpful in the case of non-cardiac problems too, but
it must always be viewed in the context of the patient
from whom the record came. The ECG must never
be a substitute for taking a proper medical history
and carrying out a careful physical examination.
Because it is simple, harmless and cheap, the ECG is
usually the first investigation in a patient with possible cardiac disease and it may be followed by the
plain chest X-ray, the echocardiogram, radionuclide
studies, CT and MR imaging, and cardiac catheterization and angiography – but none of these are substitutes. The ECG, a recording of the electrical activity
of the heart, gives information that can be obtained
in no other way. However, even though it is irreplaceable, it is not infallible.
ECGs are recorded from a wide variety of
patients, in an attempt to help with a wide variety of
possible diagnoses. An ECG is frequently recorded in
the course of ‘health screening’, but here it must be

regarded with considerable caution. It can not be
assumed that individuals who present themselves for
screening are asymptomatic – the process may be
being used as a substitute for a consultation with a
doctor. The ECG itself may cause difficulties of interpretation, for there are a dozen or more normal variants. Minor abnormalities, such as nonspecific ST
segment or T wave changes, will have diagnostic and
prognostic significance if the individual has symptoms that may be cardiac in origin, but these changes
can be of no importance in totally healthy people. It
is rare for an ECG to demonstrate anything of
importance in a totally healthy individual, although
in athletes the detection of abnormalities suggesting
asymptomatic hypertrophic cardiomyopathy is
important.
In patients with chest pain, the ECG is important
but sometimes misleading. It is essential to remember
that the ECG can remain normal for some hours
after the onset of a myocardial infarction. Too often
patients are sent home from an A & E department
because their ECG is normal, despite a reasonably

vii

Introduction

viii

convincing story of ischaemic chest pain. Under such
circumstances the ECG should be repeated several
times to see if changes are appearing, and patient
management should depend on the plasma troponin
level rather than on the ECG. Nevertheless the ECG
is important for deciding treatment in a patient with
chest pain, for the management of a patient with
myocardial infarction with ST segment elevation is
quite different from that of a patient whose ECG
shows a non-ST segment elevation infarction.
Patients with intermittent chest pain that could be
angina frequently have completely normal ECGs at
rest – and then the exercise test can be valuable. The
exercise test is to some extent being replaced by myocardial perfusion scanning for the diagnosis of coronary disease because its predictive accuracy depends
on the likelihood of the patient having angina,
because there can be false negative or false positive
results, and because exercise tests are sometimes unreliable in women. Remember that an exercise test is
safe, but not totally safe, because arrhythmias (including ventricular fibrillation) may be induced. Nev­
ertheless the exercise test has the great advantage of
showing a patient’s exercise tolerance, and also
showing what limits his capability.
The ECG also has a role in the investigation of
patients with breathlessness, for it can show changes
associated with heart disease (e.g. an old myocardial
infarction) or with chronic chest disease. Evidence of
left ventricular hypertrophy may point to hypertension, mitral regurgitation or aortic stenosis or regurgitation, and right ventricular hypertrophy may be
the result of pulmonary emboli or mitral stenosis –
however, all of these should have been detected during
the examination of the patient. The ECG is not a
good tool for grading the hypertrophy of the different
heart chambers. It is particularly important to remember that the ECG cannot demonstrate heart failure: it
may suggest a condition that may cause heart failure,
but is impossible to determine from an ECG whether

a patient is in heart failure or not. However, in the
presence of a completely normal ECG, heart failure
is certainly unlikely.
There are characteristic ECG appearances in several
conditions that are not primarily cardiac – for example
with severe electrolyte derangement. ECG monitoring
is not an acceptable way of following electrolyte
changes in conditions such as diabetic ketoacidosis,
but at least any abnormalities may prompt the appropriate biochemical tests. The ECG has, however,
become important in the development of new drugs,
for any drug that causes QT prolongation – and this
is by no means uncommon – may cause sudden death
due to ventricular tachycardia.
It is in the investigation and management of patients
with possible arrhythmias that the ECG is of paramount importance. Patients may complain of palpitations or dizziness and syncope as a result of rhythm
disturbances, and there is no way of identifying these
with certainty other than with an ECG. Dizziness and
syncope can be the result of rhythms that are either
too fast or too slow for an effective cardiac output, or
of slow rhythms associated with disorders of conduction. There may be little in the patient’s history to point
specifically to a cardiac problem when dizziness or
collapse is the main symptom, but an appropriately
abnormal ECG may immediately point to the right
diagnosis. When a patient complains of palpitations
there is a clearly a heart problem of some sort, and it
is usually possible to come close to a diagnosis by
taking a careful history – the patient with extrasystoles
will describe the heart ‘jumping out of the chest’ or
something equally unlikely, and the problem will be
worse when lying down at night, and after smoking
and alcohol. The patient with a true paroxysmal
tachycardia will describe the sudden onset (and sometimes the sudden cessation) of the rapid heartbeat, and
if the attack is associated with chest pain, dizziness or
breathlessness then the presence of a paroxysmal
tachycardia becomes highly likely.

Introduction
Few patients will have their arrhythmia at the time
they are seen, but the ECG can still give valuable clues
to its nature. A patient whose ECG shows bifascicular
block, or first degree atrioventricular block together
with left bundle branch block, may have intermittent
complete block and Stokes–Adams attacks. A patient
whose ECG shows pre-excitation (the Wolff–Parkinson–White or Lown–Ganong–Levine syndromes) is at
risk of paroxysmal arrhythmias – though many
people with these ECG patterns never have any problems at all. A patient with a prolonged QT syndrome,
as a result of either a congenital defect or drug treatment, is at risk of torsade de pointes ventricular
tachycardia. Under all these circumstances, ambulatory ECG recording, by one of a variety of techniques, may demonstrate the true nature of the
arrhythmia that causes the symptoms – but it must
be remembered that many, if not most, arrhythmias

will be seen transiently in completely healthy people
and only when an abnormal ECG corresponds
to symptoms can one be certain that the two are
related.
So the way to approach the ECG, and this book
– and indeed any medical situation – is to start with
the patient. If you cannot make a reasonable diagnosis from the history, and to a lesser extent the examination, the chances of doing so as a result of
investigations are not great. The role of the ECG and
of more complex investigations is to help differentiate
between the various possible diagnoses suggested by
talking to, and examining, the patient. The clinical
scenarios given with each ECG in this book are of
necessity brief, but think about them, ask yourself
what the diagnosis might be, and then describe and
report on the ECG. That is the way to make the most
of the ECG.

ix

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ECG 1

ECG 1

This ECG was recorded from a 20-year-old student
who complained of an irregular heartbeat. Apart from
an irregular pulse, her heart was clinically normal.
What do the ECG and chest X-ray show and what
would you do?

1

ANSWER 1
The ECG shows:
• Sinus rhythm, rate 100/min
• Ventricular extrasystoles
• Normal axis
• Normal QRS complexes and T waves
The chest X-ray is normal.

Clinical interpretation
The extrasystoles are fairly frequent but the ECG is otherwise normal.

What to do
Ventricular extrasystoles are very common. In large groups of people, there is a
correlation between the presence of extrasystoles and heart disease of many types.
However, in young people who are otherwise asymptomatic and whose hearts are
otherwise normal, the chances of a significant cardiac problem are very low.
In a young woman it is worth checking the haemoglobin level. An echocardiogram might set her mind at rest, but is not essential. The important thing is to advise
her not to smoke and to avoid alcohol, coffee and tea.
Summary
Sinus rhythm with ventricular extrasystoles.

See p. 64, 108, 8E

2

See p. 7, 6E

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ECG 2

ECG 2

A 60-year-old man was seen as an outpatient, complaining of rather vague central chest pain on exertion. He
had never had pain at rest. What does this ECG show and what would you do next?

3

ANSWER 2
The ECG shows:
• Sinus rhythm, rate 77/min
• Normal PR interval
• Normal axis
• Prominent and deep Q waves in leads II, III and VF, indicating an inferior
infarction. There are also small Q waves in leads V5–V6, but these may be septal
• ST segments normal, with no elevation in the leads showing Q waves
• Inverted T waves in leads II, III and VF

Clinical interpretation
The Q waves in the inferior leads, together with inverted T waves, point to an old
inferior myocardial infarction.

What to do
The patient seems to have had a myocardial infarction at some point in the past,
and by implication his vague chest pain may be due to angina. Attention must be
paid to risk factors (smoking, blood pressure, plasma cholesterol), and he probably
needs long-term treatment with aspirin and a statin. An exercise test or a perfusion
scan will be the best way of deciding whether he has coronary disease that merits
angiography.
Summary
Old inferior myocardial infarction.

See p. 91, 8E

4



See p. 215, 6E

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ECG 3

ECG 3

II

An 80-year-old woman, who had previously had a few attacks of dizziness, fell and broke her hip. She was found
to have a slow pulse, and this is her ECG. The surgeons want to operate as soon as possible but the anaesthetist
is unhappy. What does the ECG show and what should be done?

5

ANSWER 3
The ECG shows:
• P wave rate 130/min
• Complete heart block
• Ventricular (QRS complex) rate 23/min
• The ventricular ‘escape’ rhythm has wide QRS complexes and abnormal T
waves
No further interpretation of the ECG is possible.

Clinical interpretation
In complete heart block there is no relationship between the P waves (here with
a rate of 120/min) and the QRS complexes.

What to do
In the absence of a history suggesting a myocardial infarction, this woman almost
certainly has chronic heart block: the fall may or may not have been due to a
Stokes–Adams attack. She needs a permanent pacemaker, ideally immediately. If
permanent pacing is not possible immediately, a temporary pacemaker will be
needed preoperatively.
Summary
Complete (third degree) heart block.

See p. 41, 8E

6

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See p. 179, 6E

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ECG 4

ECG 4

A 50-year-old man is seen in the A & E department with severe central chest pain which has been present for
18 h. What does this ECG show and what would you do?

7

ANSWER 4
The ECG shows:
• Sinus rhythm, rate 64/min
• Normal axis
• Q waves in leads V2–V4
• Raised ST segments in leads V2–V4
• Inverted T waves in leads I, VL, V2–V6

Clinical interpretation
This is a classic acute ST segment elevation anterior myocardial infarction (STEMI).

What to do
More than 18 h have elapsed since the onset of pain, so this patient is outside the
conventional limit for thrombolysis or percutaneous coronary intervention (PCI).
Nevertheless, if he is still in pain and still looks unwell, PCI or thrombolytic treatment should be given unless there are good reasons not to do so. In any case, he
should be given pain relief and aspirin, and must be admitted to hospital for
observation.
Summary
Acute anterior STEMI.

See p. 91, 92, 8E

8

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See p. 217, 6E

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ECG 5

ECG 5

II

This ECG was recorded from a 60-year-old woman with rheumatic heart disease. She had been in heart failure,
but this had been treated and she was no longer breathless. What does the ECG show and what question might
you ask her?

9

ANSWER 5
The ECG shows:
• Atrial fibrillation with a ventricular rate of about 80/min
• Normal axis
• Normal QRS complexes
• Downward-sloping ST segments, best seen in leads V5–V6
• Prominent U waves in leads V2–V3

Clinical interpretation
The downward-sloping ST segments (the ‘reverse tick’) indicate that digoxin has
been given. The ventricular rate seems well controlled. The prominent U waves in
leads V2–V3 are probably normal: U waves due to hypokalaemia are associated with
flattened T waves.

What to do
Ask the patient about her appetite: the earliest symptom of digoxin toxicity is
appetite loss, followed by nausea and vomiting. If the patient is being treated with
diuretics, check the serum potassium level – a low potassium level potentiates the
effects of digoxin. If in doubt, the serum digoxin level is easily measured.

Summary
Atrial fibrillation with digoxin effect.

See p. 76, 101, 8E

10



See p. 335, 6E

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ECG 6

ECG 6

A 26-year-old woman, who has complained of palpitations in the past, is admitted to hospital via the A & E
department with palpitations. What does the ECG show and what should you do?

11

ANSWER 6
The ECG shows:
• Narrow complex tachycardia, rate about 200/min
• No P waves visible
• Normal axis
• Regular QRS complexes
• Normal QRS complexes, ST segments and T waves

Clinical interpretation
This is a supraventricular tachycardia, and since no P waves are visible this is a
junctional, or atrioventricular nodal re-entry, tachycardia (AVNRT).

What to do
AVNRT is the commonest form of paroxysmal tachycardia in young people, and
presumably explains her previous episodes of palpitations. Attacks of AVNRT may
be terminated by any of the manoeuvres that lead to vagal stimulation – Valsalva’s
manoeuvre, carotid sinus pressure, or immersion of the face in cold water. If these
are unsuccessful, intravenous adenosine should be given by bolus injection. Adenosine has a very short half-life, but can cause flushing and occasionally an asthmatic
attack. If adenosine proves unsuccessful, verapamil 5–10 mg given by bolus injection will usually restore sinus rhythm. Otherwise, DC cardioversion is indicated.

Summary
Atrioventricular nodal re-entry (junctional) tachycardia (AVNRT).

See p. 81, 8E

12

See p. 109, 6E

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ECG 7

ECG 7

This ECG was recorded in the A & E department from a 55-year-old man who had had chest pain at rest for 6 h.
There were no abnormal physical findings, and his plasma troponin level was normal. What does the trace show,
and how would you manage him?

13

ANSWER 7
The ECG shows:
• Sinus rhythm, rate 130/min
• Normal axis
• Normal QRS complexes
• ST segment depression – slightly upward-sloping in lead V3, downward-sloping
in leads I, VL, V4–V6

Clinical interpretation
This ECG shows anterior and lateral ischaemia without evidence of infarction.
Taken with the clinical history, the diagnosis is clearly ‘unstable’ angina.

What to do
There is no evidence that he would benefit from thrombolysis: percutaneous coronary intervention (PCI) would probably be the treatment of choice. Immediately,
however, he needs a beta-blocker to bring his heart rate down. Although the normal
troponin level suggests that he has not (yet) had a myocardial infarction, in view
of the length of the history it would be prudent to treat him with aspirin, heparin
and a statin.

Summary
Anterolateral ischaemia.

See p. 144, 8E

14

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See p. 212, 6E

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ECG 8

ECG 8

An 80-year-old woman complained of breathlessness and frequent attacks of dizziness. This was her ECG when
she attended the clinic. She lived alone, and it seemed unlikely that she could cope with an ambulatory
recorder. What does the ECG show, what might the dizziness be due to, and how would you manage her?

15

ANSWER 8
The ECG shows:
• Sinus rhythm, rate 90/min
• Right axis deviation
• Right bundle branch block (RBBB)

Clinical interpretation
The right axis deviation suggests left posterior hemiblock, and, combined with
RBBB, this suggests bifascicular block. The patient is therefore at risk of complete
(third degree) block, which could cause a Stokes–Adams attack.

What to do
This woman was admitted to hospital and monitored, and had a severe attack of
dizziness and fainting. During this attack, another ECG was recorded (see below).
This ECG shows complete heart block with a ventricular rate of about 15/min. The
patient was immediately given a permanent pacemaker.

See p. 41, 43,
51, 8E

Summary
Left posterior hemiblock and RBBB – bifascicular block, followed by complete
heart block (see ECG below).

See p. 89, 6E

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ECG 9

ECG 9

A 40-year-old woman is referred to the outpatient
department because of increasing breathlessness. What
do this ECG and chest X-ray show, what physical signs
might you expect, and what might be the underlying
problem? What might you do?

17

ANSWER 9
The ECG shows:
• Sinus rhythm, rate 65/min
• Peaked P waves, best seen in lead II
• Right axis deviation
• Dominant R waves in lead V1
• Deep S waves in lead V6
• Inverted T waves in leads II, III, VF, V1–V3
The chest X-ray shows a slightly enlarged heart with a high cardiac apex and a
prominent main pulmonary artery, suggesting right ventricular hypertrophy.

Clinical interpretation
This combination of right axis deviation, dominant R waves in lead V1 and inverted
T waves spreading from the right side of the heart is classic of severe right vent­
ricular hypertrophy. Right ventricular hypertrophy can result from congenital heart
disease, or from pulmonary hypertension which may be idiopathic, secondary to
mitral valve disease, lung disease, or pulmonary embolism. The physical signs of
right ventricular hypertrophy are a left parasternal heave and a displaced but diffuse
apex beat. There may be a loud pulmonary second sound. The jugular venous pressure may be elevated, and a ‘flicking A’ wave in the jugular venous pulse is characteristic of pulmonary hypertension.

What to do

See p. 87, 8E

See p. 305, 6E

18

The two main causes of pulmonary hypertension of this degree in a 40-year-old
woman are recurrent pulmonary emboli, and idiopathic (primary) pulmonary
hypertension. Clinically, it is difficult to differentiate between the two, but a lung
scan and CT pulmonary angiography will help. In either case, anticoagulants are
indicated. In fact, this patient had primary pulmonary hypertension and treatment
with high dose calcium channel blockers, prostanoids, endothelin receptor antagonists (bosentan) and phosphodiesterase inhibitors was tried, without success. Eventually she needed heart and lung transplantation.
Summary
Severe right ventricular hypertrophy.

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ECG 10

ECG 10

This ECG was recorded from an 80-year-old man who complained of breathlessness and ankle swelling which
had become slowly worse over the preceding few months. He had had no chest pain and was on no treatment.
He had a slow pulse, and signs of heart failure. What does the ECG show and how would you manage him?

19

ANSWER 10
The ECG shows:
• Atrial fibrillation with a ventricular rate of about 40/min
• Left axis deviation
• Left bundle branch block (LBBB)

Clinical interpretation
When an ECG shows LBBB, no further interpretation is usually possible. Here there
is atrial fibrillation, and the ventricular response is very slow, suggesting that there
is conduction delay in the His bundle as well as in the left bundle branch. Alternatively he may be taking too much digoxin.

What to do
It is always important to establish the cause of heart failure. In this patient the slow
ventricular rate may be at least part of the problem. The most important causes of
LBBB are ischaemia, aortic stenosis and cardiomyopathy. In this patient an echocardiogram will show whether he has significant valve disease and how impaired
his left ventricular function is. In the absence of pain, coronary angiography is
probably not indicated. The heart failure needs to be treated with diuretics and an
angiotensin-converting enzyme inhibitor, but digoxin must be avoided as it may
slow the ventricular response still further. He almost certainly needs a permanent
pacemaker.
Summary
Atrial fibrillation and LBBB.

See p. 45, 76, 8E

20

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See p. 127, 6E

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ECG 11

ECG 11

II

This ECG came from a 40-year-old woman who complained of palpitations, which were present when the
recording was made. What abnormality does it show?

21

ANSWER 11
The ECG shows:
• Lead II rhythm strip of the ECG
• The first beat has a normal P wave and is normal (i.e. a sinus beat)
• The next four beats, at about 100/min, have abnormal (inverted) P waves,
and this is an atrial tachycardia
• After a pause the next two beats have normal P waves and are in sinus rhythm
at about 60/min
• After two sinus beats there is an extrasystole with an inverted P wave; this is an
atrial extrasystole
• Normal axis
• The QRS complexes, ST segments and T waves are normal

Clinical interpretation
Since the patient had her symptoms at the time of the recording, we can be confident
that the ECG findings explain them. Atrial extrasystoles are not a manifestation of
cardiac disease, but the atrial tachycardia may be and will need treating on symptomatic grounds.

What to do
Ensure that there is no other evidence of heart disease. She should stop smoking
and avoid alcohol, coffee and tea. A beta-blocker will probably prevent the
tachycardia.
Summary
Sinus rhythm with atrial tachycardia and one atrial extrasystole.

See p. 66, 8E

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See p. 107, 6E

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ECG 12

ECG 12

II

A 70-year-old man had had high blood pressure for many years, but it was now well controlled at 140/85. He
had no symptoms, and no abnormalities were detected on physical examination. This ECG was recorded during
a routine follow-up appointment. Does it give any cause for concern, and if so, what would you do?

23

ANSWER 12
The ECG shows:
• Sinus rhythm, rate 73/min
• Normal PR interval
• Left axis deviation (left anterior hemiblock)
• Normal QRS complexes
• T wave inversion in leads I and VL

Clinical interpretation
The left axis deviation indicates a conduction defect in the anterior fascicle of the
left bundle branch – left anterior hemiblock. This is due to fibrosis, almost certainly
the result of long-standing hypertension. The T wave inversion in the lateral leads
(I and VL) probably indicates left ventricular hypertrophy, although the QRS
complex in lead V6 is not unusually tall and the ‘voltage criteria’ for left ventricular
hypertrophy are not met. It is, therefore, possible that the T wave inversion is due
to ischaemia.

What to do
This man clearly has ‘target organ’ (heart) damage as the result of his hypertension.
An echocardiogram should be recorded to assess his left ventricular thickness and
function, because the prognosis is worse if there is left ventricular hypertrophy or
if there is any reduction in function. The presence of other risk factors, such as
diabetes and hypercholesterolaemia, must be checked and, if necessary, treated. If
there is any suggestion of angina, an exercise test should be performed, but if he
really is completely asymptomatic this is probably not essential. Careful control of
his blood pressure is the key to management, and since there is evidence of cardiac
damage, an angiotensin-converting enzyme inhibitor should be the basis of
treatment.
Summary
Left anterior hemiblock and either left ventricular hypertrophy or ischaemia.

See p. 49, 8E

24

See p. 85, 6E



I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 13

ECG 13

II

This ECG was recorded from a 40-year-old man who was admitted to hospital as an emergency, with the sudden
onset of the symptoms and signs of severe left ventricular failure. What does it show and what would you do?

25

ANSWER 13
The ECG shows:
• Atrial flutter with 2 : 1 block (best seen in leads II, III, VF)
• Normal axis
• Normal QRS complexes
• The T waves are difficult to identify because of the flutter waves

Clinical interpretation
The sudden onset of atrial flutter presumably explains the heart failure. There is
nothing on the ECG to suggest a cause for the arrhythmia.

What to do
When an arrhythmia causes severe heart failure, immediate treatment is more
important than establishing the underlying diagnosis. Carotid sinus pressure and
adenosine may increase the degree of block, but are unlikely to convert the heart
to sinus rhythm. It is worth trying intravenous flecainide, but a patient with severely
compromised circulation is best promptly treated with DC cardioversion. In the
long term, ablation therapy to prevent further episodes of atrial flutter may be
needed.
Summary
Atrial flutter with 2 : 1 block.

See p. 67, 8E

26



See p. 117, 6E

I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 14

ECG 14

A 50-year-old man is admitted to hospital as an emergency, having had chest pain characteristic of a myocardial
infarction for 4 h. Apart from the features associated with pain there are no abnormal physical findings. What
does this ECG show and what would you do?

27

ANSWER 14
The ECG shows:
• Sinus rhythm, rate 72/min
• Normal axis
• Small Q waves in lead III
• Elevated ST segments in leads II, III, VF, with upright T waves
• Suggestion of ST segment depression in leads V2–V3
• T wave inversion in lead VL

Clinical interpretation
A classic ECG of an acute inferior myocardial infarction, with lead VL indicating
ischaemia. The rate of development of Q waves is very variable: compare this record
with ECG 32, which came from a patient with a similar duration of symptoms.

What to do
Pain relief must take priority. In the absence of contraindications (i.e. risk of bleeding from any important site), the patient should be given aspirin and then percutaneous coronary intervention (PCI) or a thrombolytic agent.
Summary
Acute inferior myocardial infarction.

See p. 91, 8E

28



See p. 215, 6E

I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 15

ECG 15

A 20-year-old student complains of palpitations. Attacks occur about once per year. They start suddenly, his
heart feels very fast and regular, and he quickly feels breathless and faint. The attacks stop suddenly after a few
minutes. There are no abnormalities on examination, and this is his ECG. What would you do?

29

ANSWER 15
The ECG shows:
• Sinus rhythm, rate 56/min
• Short PR interval, most obvious in the chest leads
• Normal axis
• Wide QRS complexes (136 ms)
• Slurred upstroke of the QRS complex (delta wave)
• Dominant R wave in lead V1

Clinical interpretation
This ECG is classic of Wolff–Parkinson–White (WPW) syndrome. The resemblance
to the ECG of right ventricular hypertrophy is because this is WPW type A, with a
left-sided accessory pathway.

What to do
The patient gives a clear story of a paroxysmal tachycardia, and during attacks he
feels dizzy, so the circulation is clearly compromised. The attacks are infrequent, so
there is little point in recording an ambulatory ECG. The patient needs immediate
referral to an electrophysiologist for ablation of the aberrant conducting pathway.

Summary
The WPW syndrome type A.

See p. 79, 8E

30



See p. 69, 6E

I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 16

ECG 16

II

This ECG was recorded from a 75-year-old woman who complained of attacks of dizziness. It shows one
abnormality: what is its significance?

31

ANSWER 16
The ECG shows:
• Sinus rhythm, 55/min
• Prolonged PR interval of 320 ms
• Normal axis
• RSR1 pattern in lead V1, with normal QRS complex duration: partial right
bundle branch block (RBBB)
• Normal ST segments and T waves

Clinical interpretation
Sinus rhythm with first degree block. The partial RBBB is probably not
significant.

What to do
First degree block does not cause any haemodynamic impairment, and by itself is
of little significance. However, when a patient has symptoms (in this case dizziness)
which might be due to a bradycardia, there may be episodes of second or third
degree block, or possibly Stokes–Adams attacks, associated with a slow ventricular
rate. The appropriate action is therefore to request an ambulatory ECG, recorded
over 24 h, in the hope that the patient will have one of her attacks of dizziness
during this time. It would then be possible to see whether the dizziness was associated with a change in heart rhythm. First degree block itself is not an indication for
permanent pacing or for any other intervention.

Summary
Sinus rhythm with first degree block.

See p. 37, 8E

32



See p. 184, 6E

I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 17

ECG 17

This ECG was recorded in the A & E department from a 60-year-old man who had had severe central chest pain
for 1 h. What does it show and what would you do?

33

ANSWER 17
The ECG shows:
• Sinus rhythm, rate 82/min
• One ventricular extrasystole
• Normal axis
• Q waves in leads V2–V3; small Q waves in leads VL, V4
• Raised ST segments in leads I, VL, V3–V6

Clinical interpretation
This is an acute anterolateral ST segment elevation myocardial infarction (STEMI).
Although a Q wave is well developed in lead V3, the changes are entirely consistent
with the story of pain for 1 h.

What to do
This patient needs pain relief with diamorphine. The ECG shows ST segments raised
by more than 2 mm in several leads, so he needs immediate percutaneous coronary
intervention (PCI) or thrombolysis once any risk of excessive bleeding has been
excluded. This treatment should not be delayed by waiting for a chest X-ray or any
other investigations. Ventricular extrasystoles do not need treating.
Summary
Acute anterolateral STEMI.

See p. 91, 8E

34



See p. 217, 6E

I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 18

ECG 18

A 70-year-old retired orthopaedic surgeon telephones
to say that he always gets dizzy playing golf. You find
that he has a systolic heart murmur. His ECG and chest
X-ray are shown. What is the diagnosis and what do
you do next?

35

ANSWER 18
The ECG shows:
• Sinus rhythm, rate 48/min
• Normal axis
• QRS complex duration normal, but the R wave height in lead V5 is 30 mm, and
the S wave depth in lead V2 is 25 mm
• Inverted T waves in leads I, VL, V5–V6
The chest X-ray shows an enlarged left ventricle with ‘post-stenotic’ dilatation of
the ascending aorta (arrowed).

Clinical interpretation
This is the classic ECG appearance of left ventricular hypertrophy.

What to do
See p. 118, 8E

See p. 295, 6E

36

The combination of dizziness on exercise, a systolic murmur, and evidence of left
ventricular hypertrophy suggests significant aortic stenosis. The next step is an
echocardiogram: in this patient it showed a gradient across the aortic valve of
140 mmHg, indicating severe stenosis. He needed an urgent aortic valve
replacement.
Summary
Left ventricular hypertrophy.



I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 19

ECG 19

II

A 75-year-old woman complained of central chest discomfort on climbing hills, together with dizziness; on one
occasion she had ‘fainted’ while climbing stairs. What abnormality does this ECG show and what physical signs
would you look for?

37

ANSWER 19
The ECG shows:
• Sinus rhythm, rate 79/min
• Left axis deviation
• Broad QRS complexes (192 ms)
• ‘M’ pattern in lead V6
• Inverted T waves in leads I, VL, V6

Clinical interpretation
This is the characteristic pattern of left bundle branch block (LBBB). The ECG
cannot be interpreted further.

What to do
A patient who has chest pain that could be angina, and who has dizziness and
syncope on exertion, probably has severe aortic stenosis – this was the case with
this woman. Clinically she had a slow rising pulse, a blood pressure of 100/80, and
a slightly enlarged heart. There was a loud ejection systolic murmur, best heard at
the upper right sternal edge and radiating to both carotids. The diagnosis was confirmed by an echocardiogram, which showed a gradient across the aortic valve of
about 100 mmHg. A cardiac catheter was necessary to exclude coronary disease.
She then had an aortic valve replacement, and made a complete recovery.

Summary
Sinus rhythm with LBBB.

See p. 43, 8E

38



See p. 297, 6E

I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 20

ECG 20

II

A 70-year-old man is admitted to hospital following the onset of severe central chest pain. This is his ECG. What
does it show and what treatment is needed?

39

ANSWER 20
The ECG shows:
• Sinus rhythm, rate of sinus beats 75/min
• Second degree (Wenckebach) heart block (most obvious in the rhythm strip,
recorded from lead II)
• Ventricular rate 70/min
• Normal axis
• Small Q waves in leads II, III, VF
• Raised ST segments in leads II, III, VF
• Depressed ST segments in leads V5–V6

Clinical interpretation
This patient has second degree block of the Wenckebach type (progressive lengthening of the PR interval followed by a nonconducted P wave, and then a return to a
short PR interval and repeat of the sequence). There is also clear evidence of a recent
acute inferior ST segment elevation myocardial infarction (STEMI).

What to do
The patient should be treated in the usual way for his acute myocardial infarction,
with pain relief and immediate percutaneous coronary intervention (PCI) or thrombolysis. Wenckebach second degree block is usually benign when it occurs with an
inferior infarction, and although he must obviously be monitored until sinus rhythm
with normal conduction returns, temporary pacing is not necessary.
Summary
Second degree (Wenckebach) atrioventricular block with acute inferior STEMI.

See p. 38, 8E

40

See p. 84, 6E



I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 21

ECG 21

II

This ECG was recorded from a medical student during a practical class. What does it show?

41

ANSWER 21
The ECG shows:
• Sinus rhythm, rate 70/min
• Sinus arrhythmia
• Normal axis
• Normal QRS complexes
• Normal ST segments and T waves

Clinical interpretation
This is a perfectly normal ECG. There is a beat-to-beat variation in the interval
between QRS complexes, with the heart rate speeding up and slowing down. Comparison of the rate recorded in lead VF with that recorded in lead V3 may give a
false impression of a change of rhythm, but the rhythm strip (lead II) clearly shows
the progressive alteration of the R–R interval. This variation in heart rate relates to
respiration and is called sinus arrhythmia, which is normal in young people. Sinus
arrhythmia can be distinguished from atrial extrasystoles because in sinus arrhythmia the morphology of the P waves is unchanged.

What to do
Nothing!
Summary
Normal ECG with sinus arrhythmia.

See p. 57, 8E

42



See p. 113, 6E

I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 22

ECG 22

II

This ECG was recorded from a 48-year-old man who had had severe central chest pain for 1 h. What does it
show and what would you do?

43

ANSWER 22
The ECG shows:
• Sinus rhythm, rate 75/min
• Left axis deviation (left anterior hemiblock)
• Normal QRS complexes, with a small Q wave (probably septal) in lead VL
• Inverted T waves in leads V1–V5

Clinical interpretation
This is a classic acute anterior non-ST segment elevation myocardial infarction
(NSTEMI).

What to do
This ECG does not meet the conventional criteria for immediate percutaneous coronary intervention (PCI) or thrombolysis, which are raised ST segments or new left
bundle branch block. The treatment is pain relief, aspirin, heparin, a beta-blocker
and a statin – with PCI as soon as possible. The immediate outlook is good but the
patient should be monitored and the ECG repeated after 1 h to see if ST segment
elevation is appearing.
Summary
Acute anterior NSTEMI.

See p. 142, 8E

44



See p. 241, 6E

I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 23

ECG 23

II

This ECG and chest X-ray are from a 70-year-old man who had had
angina for some time and was being treated with a beta-blocker. He
came to the A & E department complaining of pain similar to his angina,
but much more severe and persistent for 4 h. He had a heart murmur.
What do the ECG and chest X-ray show and what treatment would be
appropriate?

45

ANSWER 23
The ECG shows:
• Atrial fibrillation; ventricular rate 62/min
• Left axis deviation (left anterior hemiblock)
• Broad QRS complexes (160 ms)
• ‘M’ pattern of QRS complexes in leads V5–V6
• Inverted T waves in leads I, VL, V5–V6
The chest X-ray shows an enlarged left ventricle and a dilated ascending aorta.

Clinical interpretation
This ECG shows atrial fibrillation and left bundle branch block (LBBB). No further
interpretation is possible.

What to do
This patient has angina, and the chest X-ray suggests aortic stenosis. LBBB is characteristic of severe aortic stenosis. The problem is deciding whether his episode of
severe pain is due to a bad attack of angina or to a myocardial infarction. An aortic
dissection is also a possibility. Percutaneous coronary intervention (PCI) or thrombolytic agents should not be given unless there is evidence from previous records
that the LBBB is new, and treatment will depend on whether the plasma troponin
level is elevated. The patient urgently needs an echocardiogram, and probably needs
early cardiac catheterization with a view to aortic valve replacement. He will need
long-term anticoagulants because of the atrial fibrillation.
Summary
Atrial fibrillation and LBBB.

See p. 43, 76, 8E

46



See p. 127, 6E

I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 24

ECG 24

This ECG and chest X-ray are from a 60-year-old man being
treated as an outpatient for severe congestive cardiac
failure. What might be the diagnosis of the underlying heart
condition and what would you do?

47

ANSWER 24
The ECG shows:
• Atrial fibrillation
• Average ventricular rate 120/min
• Normal axis
• Normal QRS complexes
• Horizontal ST segment depression in leads V3–V4
• Downward-sloping ST segment depression in leads I, II, V5–V6
The chest X-ray shows a generally enlarged heart, but especially an enlarged left
ventricle and left atrium.

Clinical interpretation
The ventricular rate is not adequately controlled, though the downward-sloping ST
segment depression suggests that he is taking digoxin. The horizontal ST segment
depression suggests ischaemia.

What to do
Despite the ECG evidence of ischaemia, possible diagnoses include rheumatic heart
disease, thyrotoxicosis, alcoholic heart disease, and other forms of cardiomyopathy.
The chest X-ray suggests severe mitral regurgitation. Echocardiography is necessary.
The serum digoxin level must be checked and the digoxin dose increased if appropriate. In addition to digoxin, the patient will need an angiotensin-converting
enzyme inhibitor, a diuretic and, unless contraindicated, anticoagulants. Betablockers must be considered once his cardiac failure is controlled.
Summary
Atrial fibrillation with an uncontrolled ventricular rate, probable ischaemia
and digoxin effect.

See p. 76, 101, 8E

48

See p. 290, 6E



I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 25

ECG 25

A 60-year-old man, who 3 years earlier had had a myocardial infarction followed by mild angina, was admitted
to hospital with central chest pain that had been present for 1 h and had not responded to sublingual nitrates.
What does his ECG show, and what would you do?

49

ANSWER 25
The ECG shows:
• Sinus rhythm, rate 103/min
• Normal axis
• Q waves in leads II, III, VF
• Normal QRS complexes in the anterior leads
• Marked ST segment elevation in leads V1–V6

Clinical interpretation
The Q waves in leads III and VF suggest an old inferior infarction, while the elevated
ST segments in leads V1–V6 indicate an acute anterior ST segment elevation
infarction.

What to do
The patient should be given pain relief, and in the absence of the usual contraindications should immediately be treated with aspirin, immediate percutaneous coronary
intervention (PCI) or a thrombolytic agent. If he was treated with streptokinase for
his previous infarction, he should be given alteplase or reteplase on this occasion.
Summary
Old inferior and acute anterior myocardial infarctions.

See p. 91, 8E

50

See p. 231, 6E



I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 26

ECG 26

II

A 15-year-old boy was referred to the outpatient department because of a heart murmur. He had no symptoms.
What does this ECG show and what physical signs would you look for?

51

ANSWER 26
The ECG shows:
• Sinus rhythm, rate 83/min
• Right axis deviation
• Broad QRS complexes (140 ms)
• RSR1 pattern in leads V1–V3
• Wide and slurred S waves in lead V6
• Normal ST segments
• T wave inversion in leads III, VF and V1–V4

Clinical interpretation
Right bundle branch block (RBBB). The right axis deviation suggests left posterior
hemiblock.

What to do
RBBB is seen in a small proportion of people with otherwise perfectly normal hearts.
In the presence of a heart murmur, however, the possibility of an atrial septal defect
should be considered. This is what this patient had. The physical signs were a widely
split pulmonary second sound which did not vary with inspiration (this is typical
of RBBB), and an ejection systolic murmur best heard at the left sternal edge. On
deep inspiration a soft diastolic murmur could be heard at the lower left sternal
edge. The systolic murmur is a pulmonary flow murmur due to the extra flow
through the right side of the heart, and the diastolic murmur that occurs on inspiration is a tricuspid flow murmur. The diagnosis was confirmed by echocardiography,
and the defect was closed with a percutaneous ‘umbrella’ device. Following operation, the RBBB persisted.
Summary
Sinus rhythm with RBBB.

See p. 44, 8E

52



See p. 327, 6E

I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 27

ECG 27

II

This ECG was recorded from a 40-year-old man who complained of breathlessness on climbing stairs. He was
not aware of a fast heart rate and had had no chest pain. Apart from a rapid rate there were no cardiovascular
abnormalities, but he looked a little jaundiced and had an enlarged spleen. What would you do?

53

ANSWER 27
The ECG shows:
• Atrial flutter
• Ventricular rate 148/min
• Normal axis
• Normal QRS complexes, ST segments and T waves

Clinical interpretation
Atrial flutter with 2 : 1 block.

What to do
Provided the patient is not in heart failure, it is always a good idea to identify the
cause of an arrhythmia before treating it. The combination of an atrial arrhythmia,
jaundice and splenomegaly suggests alcoholism. The patient needs anticoagulants,
but his INR (international normalized ratio) may already be high. An echocardiogram is needed to assess left ventricular function. Carotid sinus massage will probably increase the degree of atrioventricular block, but is unlikely to correct the
arrhythmia. Digoxin, a beta-blocker or verapamil could be given in an attempt to
control the ventricular rate. After anticoagulation, cardioversion – either electrical
or with flecainide – will be necessary.
Summary
Atrial flutter with 2 : 1 conduction.

See p. 67, 8E

54



See p. 117, 6E

I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 28

ECG 28

This ECG and pulmonary angiogram are from a
39-year-old woman who complained of a recent
sudden onset of breathlessness. She had no
previous history of breathlessness, and no chest pain.
Examination revealed nothing, other than a rapid heart
rate. A pulmonary angiogram was carried out as part of
a series of investigations immediately after admission.
What is the diagnosis?

55

ANSWER 28
The ECG shows:
• Sinus rhythm, rate 140/min
• Normal conduction
• Normal axis
• Normal QRS complexes
• Slightly depressed ST segments in leads V1–V4
• Biphasic or inverted T waves in the inferior leads and all the chest leads

Clinical interpretation
The ECG shows a marked sinus tachycardia, with no change in the cardiac axis
and normal QRS complexes. The widespread ST segment/T wave changes are clearly
very abnormal, but are not specific for any particular disease. However, the fact
that leads V1–V3 are affected suggests a right ventricular problem.
The pulmonary angiogram shows a large central pulmonary embolus and occlusion of the arteries to the right lower lung.

What to do
This is a case where the ECG must be considered in the light of the patient’s history
and physical signs (if any). Clearly something has happened: the sudden onset of
breathlessness without pain suggests a central pulmonary embolus – with pulmonary emboli that do not reach the pleural surface of the lung there may be little
pain. In this patient, an echocardiogram and then a pulmonary angiogram demonstrated a large pulmonary embolus. Remember that sudden breathlessness with clear
lung fields on a routine chest X-ray is always assumed to be due to a pulmonary
embolus until proved otherwise. Heparin is essential; thrombolysis should be
considered.
Summary
Sinus tachycardia with widespread ST segment/T wave changes,
suggesting pulmonary embolism.

See p. 89, 8E

56

See p. 247, 6E



I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 29

ECG 29

This ECG was recorded from a 50-year-old man who was admitted to hospital as an emergency, having had
chest pain characteristic of a myocardial infarction for 3 h. What does the ECG show and how should the patient
be treated?

57

ANSWER 29
The ECG shows:
• Sinus rhythm, rate 65/min
• PR interval markedly prolonged (480 ms)
• Normal axis
• Normal QRS complexes
• T wave inversion in leads V1–V3

Clinical interpretation
First degree block associated with a non-ST segment elevation anterior myocardial
infarction (NSTEMI). Since the T wave inversion is in leads V1–V3 but not V4, the
possibility of a pulmonary embolus must be considered.

What to do
The ECG changes do not meet the conventional criteria for percutaneous coronary
intervention (PCI) or thrombolysis for myocardial infarction (raised ST segments or
new left bundle branch block), but the patient does need the full range of treatment
for an NSTEMI – heparin, aspirin, clopidogrel, a beta-blocker, possibly a nitrate,
and a statin. Early angiography must be considered. First degree block is not an
indication for temporary pacing, but the patient must be monitored in case higher
degrees of block develop.
Summary
First degree block and anterior NSTEMI.

See p. 98, 8E

58



See p. 184, 6E

I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 30

ECG 30

A 65-year-old man is seen in the outpatient department complaining of breathlessness and chest pain that has
the characteristics of angina. He is untreated. Does his ECG help with his diagnosis and management?

59

ANSWER 30
The ECG shows:
• Sinus rhythm, rate 48/min
• Normal axis
• Small R waves in leads V2–V4 and a normal (tall) R wave in lead V5

Clinical interpretation
The small R waves in leads V2–V4 and the ‘sudden’ appearance of a normal R wave
in lead V5 is called ‘poor R wave progression’, and despite the absence of Q waves
this probably indicates an old anterior infarction. An alternative explanation might
be poor lead positioning.

What to do
The ECG should be repeated, to ensure proper positioning of the chest leads. An
echocardiogram and a chest X-ray are needed, to see if left ventricular impairment
is responsible for the breathlessness, and stress echocardiography or perfusion
imaging are needed, to investigate the chest pain.
Summary
Poor R wave progression, suggesting an old anterior myocardial infarction.

See p. 130, 8E

60

See p. 225, 6E



I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 31

ECG 31

This ECG was recorded in a coronary care unit from a patient admitted 2 h previously with an acute anterior
myocardial infarction. The patient was cold, clammy and confused, and his blood pressure was unrecordable.
What does the ECG show and what would you do?

61

ANSWER 31
The ECG shows:
• Broad complex tachycardia, rate about 215/min
• Regular QRS complexes
• QRS complex duration uncertain: probably about 280 ms
• Indeterminate axis and QRS complex configuration

Clinical interpretation
In the context of acute myocardial infarction, broad complex tachycardias should
be considered to be ventricular in origin – unless the patient is known to have bundle
branch block when in sinus rhythm. Here the regularity of the rhythm and the very
broad complexes of bizarre configuration leave no room for doubt that this is vent­
ricular tachycardia.

What to do
In cases of severe circulatory failure, immediate DC cardioversion is needed.
Summary
Ventricular tachycardia.

See p. 73, 8E

62



See p. 126, 6E

I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 32

ECG 32

II

A 50-year-old man is admitted to hospital as an emergency, having had chest pain for 4 h. The pain is
characteristic of a myocardial infarction. Apart from signs due to pain, the examination is normal. What does this
ECG show and what would you do?

63

ANSWER 32
The ECG shows:
• Sinus rhythm, rate 38/min
• Normal axis
• Small Q waves in leads II, III, VF, V4–V6
• Normal QRS complexes in the chest leads
• Raised ST segments in leads II, III, VF and to a lesser extent in V4 and V5
• Downward-sloping ST segments in leads VL and V2

Clinical interpretation
This is an acute ST segment elevation inferior myocardial infarction (STEMI). The
rapidity of Q wave development is extremely variable, but the trace is certainly
consistent with a 4 h history. The depressed and downward-sloping ST segment in
lead V2 suggests involvement of the posterior wall of the left ventricle.

What to do
Pain relief is the most important part of the treatment. In the absence of contra­
indications, the patient should be given aspirin immediately, and then percutaneous
coronary intervention (PCI) or thrombolysis as soon as possible.
Summary
Acute inferior STEMI.

See p. 91, 138, 8E

64

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See p. 215, 6E

I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 33

ECG 33

An 80-year-old man being observed in the recovery room following a femoral–popliteal bypass operation was
noted to have this abnormal ECG. What does it show and what would you do?

65

ANSWER 33
The ECG shows:
• Sinus rhythm, rate 68/min
• Normal axis
• Normal QRS complexes
• Marked horizontal ST segment depression (about 8 mm) in leads V2–V4, and
downward-sloping ST segment depression in the lateral leads

Clinical interpretation
The patient is elderly and has peripheral vascular disease, so coronary disease is
likely to be present. The appearance of the ECG is characteristic of severe cardiac
ischaemia. The lack of a tachycardia is surprising.

What to do
This is not an easy situation to deal with because the patient’s postoperative condition dictates management. He needs anticoagulation with aspirin and heparin,
though his postoperative state may prevent this, and intravenous nitrates should be
given cautiously.
Summary
Severe anterolateral ischaemia.

See p. 144, 8E

66

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See p. 243, 6E

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VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 34

ECG 34

This ECG was recorded from a 75-year-old man who complained of breathlessness. He had not had any
chest pain or dizziness. Apart from a slow pulse, there were no abnormalities on examination. What three
abnormalities are present in this record and how would you treat the patient?

67

ANSWER 34
The ECG shows:
• Sinus rhythm; ventricular rate 45/min
• Second degree (2 : 1) block
• Left axis deviation
• Poor R wave progression in the anterior leads
• Normal T waves

Clinical interpretation
The second degree block is associated with a ventricular rate of 45/min, which may
well be the cause of his breathlessness. The left axis deviation indicates left anterior
hemiblock. The poor R wave progression (virtually no R wave in lead V3, a small
R wave in lead V4, and a normal R wave in lead V5) suggests an old anterior
infarction.

What to do
This patient needs a permanent pacemaker.
Summary
Second degree (2 : 1) block, left anterior hemiblock, and probable old
anterior infarction.

See p. 38, 8E

68

See p. 89, 6E

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VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 35

ECG 35

II

This ECG was recorded from a fit 22-year-old male medical student. He was worried – should he have been?

69

ANSWER 35
The ECG shows:
• Sinus rhythm, rate 44/min
• Normal axis
• Tall R waves (23 mm in lead V5) and deep S waves (41 mm in lead V2)
• Normal ST segments and T waves
• Prominent U waves in leads V2–V5

Clinical interpretation
This record shows left ventricular hypertrophy by ‘voltage criteria’ (R waves greater
than 25 mm in lead V5 or V6, or the sum of the R wave in lead V5 or V6 plus the
S wave in lead V1 or V2 is greater than 35 mm). There are, however, no T wave
changes. ‘Voltage criteria’ on their own are unreliable, and in a fit young man this
may well be a normal variant. The U waves are perfectly normal, and this pattern
is common in athletes.

What to do
Tell the student to buy a good book on ECG interpretation, but if reassurance
is not enough, echocardiography could be used to measure the left ventricular
thickness.
Summary
Left ventricular hypertrophy on ‘voltage criteria’, but probably normal.

See p. 90, 8E

70

See p. 19, 6E

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VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 36

ECG 36

A 70-year-old man was seen as an outpatient with symptoms
and signs of heart failure. His problem had begun quite suddenly
a few weeks previously, when he had had a few hours of dull
central chest discomfort. What do his ECG and the enlarged part
of his chest X-ray show and what would you do?

71

ANSWER 36
The ECG shows:
• Sinus rhythm, rate 100/min
• Normal axis
• Q waves in leads I, VL, V2–V5
• Raised ST segments in leads I, VL, V2–V6
The chest X-ray shows diversion of blood flow to the upper zones of the lungs,
which is an early radiological sign of heart failure.

Clinical interpretation
The raised ST segments suggest an acute infarction, but the deep Q waves suggest
that the infarction occurred at least several hours previously. From the patient’s
story it seems clear that he had an infarction several weeks before he was seen, and
there was nothing in the history to suggest a more recent episode. These ECG
changes are therefore probably all old; the anterior changes might indicate a left
ventricular aneurysm.

What to do
An ECG should always be interpreted in the light of the patient’s clinical state. Since
the ECG is compatible with an old infarction it should be assumed that this diagnosis is correct, and the patient should be treated for heart failure in the usual way
with diuretics, angiotensin-converting enzyme inhibitors and beta-blockers. Since
the heart failure is clearly due to ischaemia he also needs aspirin and a statin.
Summary
Anterolateral myocardial infarction of uncertain age.

See p. 91, 8E

72

See p. 225, 6E

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VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

I

VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 37

ECG 37

A 60-year-old man was referred to the outpatient department because of exercise-induced chest pain. The
upper ECG is his record at rest, and the lower one was taken during stage 1 of the Bruce exercise protocol
(1.7 mph and 10% grade on the treadmill). What do these ECGs show and what would you do?

73

ANSWER 37
Upper ECG
The ECG shows:
• Sinus rhythm, rate 75/min
• Normal axis
• Normal QRS complexes
• Slight ST segment depression in leads II, VF, V6
• T wave inversion in lead III

Clinical interpretation
The ST segment changes in leads II, VF and V6 are nonspecific, and the T wave
inversion in lead III could well be a normal variant. Nevertheless, with the story of
exercise-induced chest pain a diagnosis of angina seems likely, and an exercise test
is the appropriate next step.

Lower ECG
The ECG shows:
• Sinus rhythm at 140/min
• Normal axis
• Normal QRS complexes
• ST segment depression in most leads, the maximum being 4 mm in lead V5

Clinical interpretation
The resting ECG shows only nonspecific changes, but the ECG on exercise shows
the classic changes of ischaemia – appearing during the first stage of the Bruce
protocol. Even this light exercise level markedly increased the heart rate. Both the
inferior and the anterior chest leads show definite ischaemia, so widespread coronary disease is likely, possibly including the main stem of the left coronary artery.

What to do

See p. 144, 8E

74

See p. 270, 6E

This patient can be treated immediately with short- and long-acting nitrates, betablockers and calcium antagonists, but he also needs urgent coronary angiography
with a view to percutaneous coronary intervention (PCI) or coronary artery bypass
graft surgery. Risk factors such as smoking, weight and hypercholesterolaemia must
also be addressed.
Summary
Nonspecific ECG changes at rest; strongly positive exercise test.



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V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 38

ECG 38

II

A 70-year-old man with long-standing high blood pressure has had attacks of dizziness over several weeks. His
pulse feels irregular but there are no other abnormal signs. This was his ECG. What does it show and what
would you do?

75

ANSWER 38
The ECG shows:
• The first nine beats with sinus rhythm and a ventricular rate of about 80/min
• The PR interval in these nine beats slowly increases, from 240 ms to 360 ms
• There is then a nonconducted P wave, followed by a conducted P wave with a
PR interval of 360 ms
• There is then a second nonconducted P wave, followed by two conducted P
waves, again with a PR interval of 360 ms
• Normal axis
• Normal QRS complexes, ST segments and T waves

Clinical interpretation
This ECG shows a mixture of different types of heart block. The progressively
increasing PR intervals followed by a nonconducted P wave represent second degree
block of the Wenckebach (Mobitz type 1) type. The next nonconducted P wave
followed by a conducted P wave with a long PR interval is second degree block of
Mobitz type 2. The final beat, with the same prolonged PR interval, shows first
degree block. The changing heart rate is presumably the cause of his attacks of
dizziness.

What to do
Since this man has had no pain, and there is no evidence of ischaemia on the ECG,
it is perhaps unlikely that coronary disease is responsible for the conduction problem.
You should always think about myocarditis, and about infiltrative diseases that
might affect the bundle of His, but in a hypertensive patient the most likely cause
of this sort of heart block is medication. He may well be taking either a beta-blocker
or a calcium-blocker, and the first thing to do would be to discontinue these.
Summary
Second degree block of both the Wenckebach type and Mobitz type 2,
and also first degree block.

See p. 38, 8E

76

See p. 179, 6E

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VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 39

ECG 39

II

A 70-year-old woman, from whom this ECG was recorded, was admitted to hospital with increasing congestive
cardiac failure. What does the ECG show and what would you do?

77

ANSWER 39
The ECG shows:
• Atrial fibrillation, rate about 110/min
• Normal axis
• Normal QRS complexes
• Normal ST segments

Clinical interpretation
The rhythm could be interpreted as atrial flutter, particularly in lead VL. However,
the flutter-like activity is variable, and the QRS complexes are completely irregular,
so this is atrial fibrillation. The ST segments are normal, with no suggestion of
digoxin effect, and the ventricular rate is not controlled, so the patient is probably
not taking digoxin.

What to do
The ventricular rate in this case is rapid, and the uncontrolled rate may be contributing to the patient’s heart failure. Her thyroid function tests should be checked,
and she needs an echocardiogram to assess heart size and left ventricular function.
The heart rate needs to be controlled, and digoxin is the first drug to use. Her heart
failure must be treated with a diuretic and probably an angiotensin-converting
enzyme inhibitor, and then a decision has to be taken regarding cardioversion. This
is unlikely to be successful unless some remediable cause of the atrial fibrillation,
such as thyrotoxicosis, is detected. At this age, she will need life-long anticoagulation with warfarin, whatever her echocardiogram shows.
Summary
Atrial fibrillation with an uncontrolled ventricular rate.

See p. 76, 8E

78

See p. 290, 6E

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VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 40

ECG 40

II

This ECG was recorded from a 30-year-old woman who complained of palpitations. Does it help in making a
diagnosis?

79

ANSWER 40
The ECG shows:
• Ectopic atrial rhythm, with inverted P waves in leads II, III, VF, V3–V6;
ventricular rate 69/min
• Normal axis
• Normal QRS complexes and T waves

Clinical interpretation
This appears to be a stable rhythm originating in the atrial muscle rather than the
SA node – hence the abnormal P wave and the slightly short PR interval (130 ms).
This rhythm is not uncommon, and is usually of no clinical significance. It is unlikely
to be the cause of her symptoms unless at times she has a paroxysmal atrial
tachycardia.

What to do
Take a careful history and attempt to determine whether her symptoms sound like
a paroxysmal tachycardia – ask about any sudden onset and ending of the palpitations; associated symptoms like breathlessness; precipitating and terminating factors;
and so on. If in doubt, some sort of ambulatory recording will be needed.
Summary
Ectopic atrial rhythm.

See p. 111, 8E

80

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See p. 7, 6E

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V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 41

ECG 41

This ECG was recorded from a healthy 25-year-old man during a routine medical examination. Any comments?

81

ANSWER 41
The ECG shows:
• A very odd appearance
• Sinus rhythm, rate 70/min
• Inverted P waves in lead I
• Right axis deviation
• Dominant R waves in lead VR
• No R wave development in the chest leads, with lead V6 still showing a right
ventricular pattern
• Normal-width QRS complexes

Clinical interpretation
This is dextrocardia. A normal trace would be obtained with the limb leads reversed
and the chest leads attached in the usual rib spaces but on the right side of the chest.

What to do
Ensure that the leads are properly attached – for example, inverted P waves in lead
I will be seen if the right and left arm attachments are reversed. Of course, this
would not affect the appearance of the ECG in the chest leads.
Summary
Dextrocardia.

See p. 19, 8E

82

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See p. 10, 6E

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VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 42

ECG 42

An 80-year-old woman, who has apparently been treated for heart failure for years, complains of nausea and
vomiting. No previous records are available. Does her ECG help her management?

83

ANSWER 42
The ECG shows:
• Atrial fibrillation, ventricular rate 80/min
• Normal axis
• Normal QRS complexes
• Downward-sloping ST segment depression, especially in leads V4–V6
• T waves probably upright
• Prominent U waves in leads V2–V3

Clinical interpretation
The ECG shows atrial fibrillation with a controlled ventricular rate. There is nothing
on the ECG to suggest a cause for the arrhythmia or the patient’s heart failure. The
‘reversed tick’ ST segment depression suggests that she is being treated with digoxin.
The ECG does not suggest digoxin toxicity, but nevertheless this is the most likely
cause of her nausea. The U waves may be normal, but raise the possibility of
hypokalaemia.

What to do
Digoxin therapy should be temporarily discontinued, and her plasma potassium and
digoxin levels should be checked.
Summary
Atrial fibrillation and digoxin effect.

See p. 101, 8E

84

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See p. 335, 6E

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VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 43

ECG 43

A 60-year-old man, whose heart and preoperative ECG
had been normal, developed a cough with pleuritic
chest pain a few days after a cholecystectomy. These
are his ECG and chest X-ray: what do they show and
what might be the problem?

85

ANSWER 43
The ECG shows:
• Atrial fibrillation
• Normal axis
• RSR1 pattern in leads V1–V3, indicating right bundle branch block (RBBB)
The chest X-ray shows a large pleural effusion on the right side with some atelectasis
above it, and also a small left-sided effusion. There is upper-zone blood diversion,
indicating heart failure.

Clinical interpretation
In this ECG the usual ‘irregular baseline’ of atrial fibrillation is not apparent, but
the QRS complexes are so irregular that this must be the rhythm. The rhythm
change, together with the development of RBBB, could be due to a chest infection
but is more likely to have been caused by a pulmonary embolus. The right-sided
pleural effusion could also be due to either infection or embolism, but the patient
clearly has heart failure because the effusions are bilateral (although asymmetrical)
and there is diversion of blood flow to the upper zones of the lungs.

What to do
In a postoperative patient, anticoagulation can always cause haemorrhage. Nevertheless, the risk of death from a pulmonary embolus is so high that the patient
should immediately be given heparin while steps are taken (white blood cell count,
sputum culture, CT scan) to differentiate between a chest infection and a pulmonary
embolus.
Summary
Atrial fibrillation with RBBB.

See p. 43, 76, 8E

86

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See p. 125, 6E

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VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 44

ECG 44

This ECG and chest X-ray were recorded in the A & E
department from a 50-year-old man with severe
central chest pain that radiated into his back. The pain
had been present for 6 h. What do the ECG and X-ray
show and what would you do?

87

ANSWER 44
The ECG shows:
• Sinus rhythm, rate 88/min
• PR interval 320 ms – first degree block
• Q waves in leads II, III, VF
• Raised ST segments in leads II, III, VF
• Inverted T waves in leads III, VF
The chest X-ray shows opacification of the left side of the chest, with probable shift
of the mediastinum to the right.

Clinical interpretation
This ECG shows an acute inferior myocardial infarction, which often causes first
degree block. The Q waves and raised ST segments are consistent with the story of
6 h of chest pain, and the first degree block is not important.

What to do
Chest pain radiating through to the back has to raise the possibility of aortic dissection, which can occlude the opening of the coronary arteries and so cause a
myocardial infarction. However, this is relatively rare compared with back pain
associated with myocardial infarction, which is common. In this case, the chest
X-ray suggests that blood has leaked into the left pleural cavity from a dissection
of the aorta. Thrombolysis for the myocardial infarction is obviously contraindicated, and the patient needs immediate investigation by CT or MR scanning to see
if surgical repair of the dissection is possible.
Summary
Acute inferior myocardial infarction with first degree block, due to dissection of
the aorta.

See p. 91, 8E

88

See p. 215, 6E

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VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 45

ECG 45

This ECG was recorded from a 23-year-old pregnant woman who had complained of palpitations, and who had
been found to have a heart murmur. What does it show and what might be the problem?

89

ANSWER 45
The ECG shows:
• Sinus rhythm, underlying rate 61/min
• Supraventricular (atrial) extrasystoles
• Normal PR interval
• Normal axis
• Wide QRS complex (160 ms)
• RSR1 pattern in lead V1
• Broad slurred S wave in lead V6
• Inverted T waves in leads V1–V3

Clinical interpretation
The broad QRS complex with an RSR1 pattern in lead V1 and a slurred S wave in
lead V6, together with the inverted T waves in leads V1–V3, indicate right bundle
branch block (RBBB). The extrasystoles are supraventricular because they have the
same (abnormal) QRS pattern as the sinus beats; they are atrial in origin because
each is preceded by a T wave of slightly different shape from the sinus beats.

What to do
The palpitations of which the patient complains may well be due to the extrasystoles: it is important to ensure that they correspond to her symptoms. RBBB in a
young person may indicate an atrial septal defect, and she should have an echocardiogram. The heart murmur could be due to a septal defect, but could well be a
‘flow murmur’ due to the increased cardiac output associated with pregnancy.
Summary
RBBB and atrial extrasystoles.

See p. 43, 8E

90

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See p. 115, 6E

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V1

V4

II

VL

V2

V5

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ECG 46

ECG 46

This ECG was recorded from a 9-year-old girl who was asymptomatic but who had been found to have a heart
murmur at a school medical examination. What does it tell you about the murmur?

91

ANSWER 46
The ECG shows:
• Sinus rhythm, rate 107/min
• Normal axis
• Normal QRS complexes, but narrow, deep Q waves in leads I, II, V4–V6
• Inverted T waves in lead V1

Clinical interpretation
A sinus tachycardia with normal QRS complexes, showing prominent ‘septal’ Q
waves, is characteristic of ECGs of children. The inverted T wave in lead V1 is
normal at any age. A normal ECG helps to exclude serious causes of heart murmurs,
but the record has not been very helpful in this case.

What to do
If in doubt, an echocardiogram will show whether there is any important structural
abnormality of the heart.
Summary
Normal ECG in a 9-year-old child.

See p. 53, 6E

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V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 47

ECG 47

This ECG and chest X-ray were recorded from a
diabetic man who was admitted to hospital because
of the sudden onset of pulmonary oedema. What do
you think has happened?

93

ANSWER 47
The ECG shows:
• Atrial fibrillation with a ventricular rate of about 180/min
• Left axis deviation
• Probable Q waves in leads V2–V4
• QRS complexes of normal width and height
• Raised ST segments in leads I, VL, V2–V4
The chest X-ray shows pulmonary oedema; it is difficult to see the heart borders.

Clinical interpretation
This ECG shows uncontrolled atrial fibrillation with left anterior hemiblock and an
acute anterolateral ST segment elevation myocardial infarction (STEMI). The onset
of atrial fibrillation may have been the cause or the consequence of the myocardial
infarction, and the rapid ventricular rate will at least in part explain the pulmonary
oedema. The left anterior hemiblock is probably a consequence of the infarction.
The patient may not have experienced pain because of his diabetes.

What to do
The most important thing is to relieve the patient’s distress and the pulmonary
oedema. He needs diamorphine, an intravenous diuretic, intravenous nitrates, and
intravenous digoxin to control the ventricular rate – all with careful monitoring.
Attention can then be turned to the treatment of his myocardial infarction. He will
need anticoagulation with heparin.
Summary
Atrial fibrillation, left anterior hemiblock and acute anterolateral STEMI.

See p. 49, 76, 91, 8E

94

See p. 217, 6E

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V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 48

ECG 48

This ECG was recorded from a young man seen in the outpatient department because of chest pain which
appeared to be nonspecific. How would you interpret the ECG and what action would you take?

95

ANSWER 48
The ECG shows:
• Sinus rhythm, rate 71/min
• Normal axis
• Normal QRS complexes
• Inverted T waves in leads III, VF; biphasic T waves in lead V4; flattened T
waves in leads V5–V6
• U waves in leads V2–V3 (normal)

Clinical interpretation
These T wave changes, particularly those in the inferior leads, could well be caused
by ischaemia. The flattened T waves in the lateral leads can only be described as
‘nonspecific’.

What to do
When confronted with an ECG showing this sort of ‘nonspecific’ abnormality,
action depends primarily on the clinical diagnosis. If the patient is asymptomatic it
is fair to report the ECG as showing ‘nonspecific changes’; if the patient has symptoms at all – as in this case – it is probably worth proceeding to an exercise test. In
this patient, the exercise test was perfectly normal, and his symptoms cleared
without any intervention. A repeat ECG, recorded purely out of interest a month
later, showed similar changes.
Summary
Nonspecific ST segment and T wave changes.

See p. 123, 8E

96

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V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 49

ECG 49

This ECG was recorded from a 65-year-old woman admitted to hospital as an emergency because of severe
chest pain for 1 h. What does the ECG show? What other investigations would you order?

97

ANSWER 49
The ECG shows:
• Sinus rhythm, rate 111/min
• Normal axis
• Probably normal QRS complexes
• Gross elevation of ST segments in anterior and lateral leads
• Depressed ST segments in the inferior leads (III, VF)

Clinical interpretation
Acute ST segment elevation anterolateral myocardial infarction (STEMI). In the
lateral leads I, VL and V4–V6, it is difficult to see where the QRS complexes end
and the ST segments begin, but in lead II it is clear that the QRS complex is of
normal width.

What to do
If the patient gives a history suggestive of a myocardial infarction and has this ECG,
no further investigations are needed in the acute phase of the illness, and in parti­
cular there is no place for a chest X-ray. Routine treatment for a myocardial
infarction – pain relief, aspirin and percutaneous coronary intervention (PCI) or
thrombolysis – should be commenced immediately.
Summary
Acute anterolateral STEMI.

See p. 91, 8E

98

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See p. 217, 6E

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VR

V1

II

VL

V2

III

VF

V3

V4

V5

ECG 50

ECG 50

V6

A 45-year-old woman had complained of occasional attacks of palpitations for 20 years, and eventually this ECG
was recorded during an attack. What are the palpitations due to, and what would you do?

99

ANSWER 50
The ECG shows:
• Narrow complex tachycardia at 188/min
• No P waves visible
• Normal axis
• QRS complexes normal
• Some ST segment depression

Clinical interpretation
This ECG shows supraventricular tachycardia. This rhythm is usually due to a
re-entry pathway within, or near to, the atrioventricular node, so the rhythm is
properly called AV nodal re-entry tachycardia (AVNRT), although the term ‘supraventricular tachycardia’ is often (inappropriately) used. The ST segment depression
could indicate ischaemia, but the ST segments are not horizontally depressed, nor
is the depression greater than 2 mm, so it is probably of no significance.

What to do
The first action is carotid sinus pressure, which may terminate the attack. If this
fails it will almost certainly respond to adenosine. As with any tachycardia, electrical
cardioversion must be considered if there is haemodynamic compromise. Once sinus
rhythm has been restored, the patient must be taught the various methods (e.g. the
Valsalva manoeuvre) with which she might try to terminate an attack. Prophylactic
medication may not be needed if attacks are infrequent, but most patients with this
problem should have an electrophysiological study to try to identify a re-entry
pathway that can be ablated.
Summary
AV nodal re-entry (junctional) tachycardia (AVNRT).

See p. 81, 8E

100

See p. 109, 6E

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VR

V1

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II

VL

V2

V

III

VF

V3

V

5

ECG 51

ECG 51

6

II

This ECG was recorded from a 35-year-old woman who complained of breathlessness but not of pain. She was
anxious, but there were no abnormalities on examination. Does this ECG help with her diagnosis and
management?

101

ANSWER 51
The ECG shows:
• Sinus rhythm, rate 106/min
• Normal axis
• Normal QRS complexes (septal Q waves in leads I and VL)
• Slight ST segment depression, especially in leads II and V6
• T wave flattening in leads II, III, VF, V6
• T wave inversion in lead III

Clinical interpretation
A sinus rate of over 100/min would be compatible with anxiety, though other
causes of ‘high output’ (e.g. pregnancy, thyrotoxicosis, anaemia, volume loss, CO2
retention, beri-beri) have to be considered. The widespread ST segment and T wave
changes have to be described as ‘nonspecific’; in an anxious patient they could
be due to hyperventilation. The ECG does not help with the diagnosis and
management.

What to do
If a full history and examination fail to suggest any underlying physical disease,
further investigations are unlikely to be helpful.
Summary
Nonspecific ST segment and T wave changes.

See p. 101, 8E

102

See p. 35, 6E

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VR

V1

V4

II

VL

V2

V5

III

VF

V3

V6

ECG 52

ECG 52

This ECG was recorded from a 60-year-old man seen in the clinic because of severe breathlessness, which had
developed over several years. His jugular venous pressure is raised. What do you think the problem is?

103

ANSWER 52
The ECG shows:
• Sinus rhythm, rate 140/min
• One ventricular extrasystole
• Peaked P waves (best seen in leads II, III, VF)
• Normal PR interval
• Right axis deviation
• Dominant R wave in lead V1
• Deep S wave in lead V6
• Normal ST segments and T waves

Clinical interpretation
The sinus tachycardia suggests a major problem. The peaked P waves indicate right
atrial hypertrophy. The right axis deviation and dominant R wave in lead V1 suggest
right ventricular hypertrophy. The deep S wave in lead V6, with no ‘left ventricular’
complexes in the chest leads, indicates ‘clockwise rotation’ of the heart, with the
right ventricle occupying the precordium. These changes suggest lung disease.

What to do
Since the ECG is entirely ‘right-sided’, one can assume that the problem is due to
chronic lung disease or recurrent pulmonary embolism. The story sounds more in
keeping with a lung problem. The raised jugular venous pressure is presumably due
to cor pulmonale. The sinus tachycardia is worrying, and suggests respiratory
failure.
Summary
Sinus tachycardia and one ventricular extrasystole; right atrial and right ventricular
hypertrophy; and clockwise rotation – suggesting chronic lung disease.

See p. 19, 8E

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ECG 53

ECG 53

A 60-year-old man is seen in the outpatient
department complaining of breathlessness which
began quite suddenly 2 months previously. He had
had no chest pain. Examination revealed a raised
jugular venous pressure, basal crackles in the lungs
and a third sound at the cardiac apex. These are his
ECG and chest X-ray. What do they show and how
does this fit the clinical picture? What would you do?

105

ANSWER 53
The ECG shows:
• Sinus rhythm, rate 72/min
• Normal axis
• Large Q waves in leads V1–V4 and small Q waves in leads I, VL
• Elevated ST segments and inverted T waves in leads V2–V5
• Flattened T waves in leads I and V6; inverted T waves in lead VL
The chest X-ray shows a left ventricular aneurysm.

Clinical interpretation
This ECG would be compatible with an acute anterior myocardial infarction, but
this does not fit the clinical picture: it appears that an event occurred 2 months
previously. This pattern of ST segment elevation in the anterior leads can persist
following a large infarction, and is often seen in the presence of a ventricular aneur­
ysm. This is confirmed by the chest X-ray.

What to do
An echocardiogram will show the extent of the aneurysm and whether the remaining
left ventricular function is impaired, which it almost certainly will be. The patient
should be treated with diuretics and an angiotensin-converting enzyme inhibitor,
and surgical resection of the aneurysm might be considered.
Summary
Old anterior myocardial infarction with a left ventricular aneurysm.

See p. 130, 8E

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See p. 225, 6E

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V

3

ECG 54

ECG 54

6

The senior house officer in the A & E department is
puzzled by this ECG which was recorded from an
80-year-old admitted unconscious with a stroke.
What has the house officer missed? Perhaps he did
not make a proper examination and did not look at
the chest X-ray?

107

ANSWER 54
The ECG shows:
• Regular rhythm at 60/min
• Occasional P waves, not related to QRS complexes (e.g. in lead I)
• Left axis deviation
• QRS complexes preceded by a sharp ‘spike’
• Broad QRS complexes (160 ms)
• Deep S wave in lead V6
• Inverted T waves in leads I, VL
The chest X-ray shows a permanent pacemaker, with a single lead in the right
ventricle.

Clinical interpretation
The broad QRS complexes show that this is either a supraventricular rhythm with
bundle branch block, or a ventricular rhythm. This rhythm is ventricular. The sharp
spikes preceding each QRS complex are due to the pacemaker. The P waves that
can occasionally be seen indicate that the underlying rhythm is complete heart
block – presumably the reason why the pacemaker was inserted.

What to do
The house officer has missed the pacemaker, which is usually buried below the left
clavicle. There is no particular reason why the pacemaker should be related to the
stroke, except that patients with vascular disease in one territory usually have it in
others – this man probably has both coronary and cerebrovascular disease.
Summary
Permanent pacemaker and underlying complete block.

See p. 169, 8E

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ECG 55

ECG 55

A 70-year-old woman who complained of ‘dizzy turns’ was found to have an irregular pulse, and this ECG was
recorded. There are three abnormalities. What advice would you give her?

109

ANSWER 55
The ECG shows:
• Sinus rhythm; sinus rate 100/min
• Normal and constant PR intervals in the conducted beats
• Occasional nonconducted P waves (best seen in lead I)
• Left axis deviation
• Right bundle branch block (RBBB)

Clinical interpretation
This ECG shows second degree block (Mobitz type 2) and bifascicular block – left
axis deviation (left anterior hemiblock) and RBBB. This combination of conduction
abnormalities indicates disease throughout the conduction system, and is sometimes
called ‘trifascicular’ block.

What to do
The ‘dizzy turns’ may represent intermittent complete block. Permanent pacing is
essential.
Summary
Second degree block (Mobitz type 2) and bifascicular block.

See p. 39, 8E

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I (continuous record)

II (continuous record)

ECG 56

ECG 56

III (continuous record)

A 50-year-old man, who had come to the A & E department with chest pain, collapsed while his ECG was being
recorded. What happened and what would you do?

111

ANSWER 56
The ECG shows:
• Sinus rhythm initially 55/min, with ventricular extrasystoles
• The third extrasystole occurs on the peak of the T wave of the preceding sinus
beat
• After three or four beats of ventricular tachycardia, ventricular fibrillation
develops
• In the sinus beats there is a Q wave in lead III; and there are raised ST segments
in leads II and III, and ST segment depression and T wave inversion in lead I

Clinical interpretation
Although only leads I, II and III are available, it looks as if the chest pain was due
to an inferior myocardial infarction. This was probably the cause of the ventricular
extrasystoles, and an ‘R on T’ extrasystole caused ventricular tachycardia, which
rapidly decayed into ventricular fibrillation. It might be argued that in lead III, and
perhaps also in lead I, ‘torsade de pointes’ ventricular tachycardia is present, but
this is not apparent in lead II.

What to do
Precordial thump and immediate defibrillation, but if no defibrillator is at hand then
cardiopulmonary resuscitation should be performed, and the usual procedure for
the management of cardiac arrest instituted.
Summary
Probable inferior myocardial infarction; R on T ventricular extrasystole, causing
ventricular fibrillation.

See p. 79, 8E

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ECG 57

ECG 57

A 60-year-old man complained of severe central chest pain, and a few minutes later became extremely
breathless and collapsed. He was brought to the A & E department, where his heart rate was found to be
165/min, his blood pressure was unrecordable and he had signs of left ventricular failure. This is his ECG.
What has happened and what would you do?

113

ANSWER 57
The ECG shows:
• Broad complex tachycardia at 165/min
• No P waves visible
• QRS complex duration about 200 ms
• Concordance of QRS complexes (i.e. all point upwards) in the chest leads

Clinical interpretation
A broad complex tachycardia can be ventricular in origin, or can be due to a supraventricular tachycardia with aberrant conduction (i.e. bundle branch block). Here
the very broad complexes and the QRS complex concordance suggest a ventricular
tachycardia. In a patient with a myocardial infarction it is always safe to assume
that such a rhythm is ventricular. From the story, one would guess that this patient
had a myocardial infarction and then developed ventricular tachycardia, but it is
possible that the chest pain was due to the arrhythmia.

What to do
This patient has haemodynamic compromise – low blood pressure and heart
failure – and needs immediate cardioversion. While preparations are being made it
would be reasonable to try intravenous lidocaine or amiodarone.
Summary
Ventricular tachycardia.

See p. 73, 8E

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I

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V3

V6

A 70-year-old man gave a history of several years of chest pain on exertion. These are his ECGs at rest (upper
trace) and on exercise (lower trace). What do they show?

ECG 58

ECG 58

115

ANSWER 58
The upper ECG shows:
• Sinus rhythm, rate 68/min
• Right axis deviation
• Small Q waves in leads III, VF
• Persistent S wave in leads V5–V6
• Inverted T waves in leads II, III, VF, V1–V5
The lower record was taken during stage 2 of the Bruce protocol. It shows:
• Sinus rhythm at 100/min
• T wave inversion persists in leads II, III, VF; but the T waves are now upright
in the chest leads

Clinical interpretation
The widespread T wave inversion suggests a non-ST segment elevation myocardial
infarction, although there is nothing in the history to suggest when this occurred.
The S wave in lead V6 suggests the possibility of chronic lung disease. The change
in the T waves in the anterior leads, from inverted at rest to normal on exercise, is
an example of ‘pseudonormalization’, which is an indication of ischaemia.

What to do
‘Pseudonormalization’ must be regarded in the same way as the usual ST segment
response to ischaemia, which is depression. This patient’s exercise test was positive
(i.e. indicates ischaemia) at a relatively low level – so although his symptoms can
be treated medically in the usual way, a coronary angiogram with a view to intervention is indicated. The risk factors for coronary disease must be assessed and
treated, whatever course of action is chosen.
Summary
Ischaemia with ‘pseudonormalization’ of the ECG on exercise.

See p. 275, 6E

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ECG 59

ECG 59

II

This ECG was recorded from a 70-year-old woman who complained of an irregular heartbeat. What does it show
and what would you do?

117

ANSWER 59
The ECG shows:
• Atrial fibrillation, rate about 110/min
• Frequent multifocal ventricular extrasystoles
• Normal axis in the sinus beats
• Loss of R waves in leads V3–V4
• There is downward-sloping ST segment depression in lead V6

Clinical interpretation
This ECG shows an old anterior myocardial infarction, so ischaemia is probably
(but not certainly) the cause of the patient’s atrial fibrillation and extrasystoles. The
ventricular rate is not well controlled. The ST segment depression suggests that she
is taking digoxin.

What to do
It would be prudent to check the patient’s serum potassium and digoxin levels to
make sure that the extrasystoles are not a manifestation of digoxin toxicity. An
echocardiogram should be recorded to check her heart size and left ventricular
function; remember that atrial fibrillation may be the only indication of thyrotoxicosis in the elderly. Her complaint of palpitations may be due to her atrial fibrillation
or to the extrasystoles (or both). The extrasystoles themselves are not important,
but she should avoid smoking, alcohol and caffeine. A beta-blocker may reduce the
extrasystoles as well as control her ventricular rate. It is unlikely that cardioversion
would be successful, and she will need long-term treatment with digoxin, possibly
a beta-blocker, probably an angiotensin-converting enzyme inhibitor, and certainly
anticoagulants.
Summary
Atrial fibrillation, multifocal ventricular extrasystoles, and an old anterior
myocardial infarction.

See p. 64, 8E

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ECG 60

ECG 60

A 60-year-old man who was being treated in hospital complained of palpitations, and this ECG was recorded.
What do you think the underlying disease was, and what were the palpitations due to?

119

ANSWER 60
The ECG shows:
• Atrial fibrillation
• Ventricular extrasystoles with two distinct morphologies (best seen in lead II)
• A four-beat run of ventricular tachycardia
• Right axis deviation
• Small QRS complexes
• No R wave development in the chest leads; lead V6 shows a dominant S wave
• T wave inversion in leads V5–V6

Clinical interpretation
This ECG suggests chronic lung disease – small complexes, right axis deviation, and
marked ‘clockwise rotation’, with lead V6 still showing a right ventricular type of
complex (i.e. a complex with a small R wave and a deeper S wave, as normally seen
in lead V1). The atrial fibrillation is probably secondary to the lung disease, though
the other possibilities must be considered. The patient’s lung condition is probably
being treated with a beta-agonist, such as salbutamol, and this could be the cause
of the extrasystoles and ventricular tachycardia.

What to do
Stop the beta-agonist but do not give a beta-blocker. Check the electrolyte levels;
consider the possibility of digoxin toxicity.
Summary
Atrial fibrillation with ventricular extrasystoles and ventricular tachycardia;
changes suggesting chronic lung disease.

See p. 19, 73, 8E

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ECG 61

ECG 61

II

A 45-year-old man complained of palpitations, weight loss and anxiety. His blood pressure was 180/110, and his
heart seemed normal. This is his ECG. His thyroid function tests, measured several times, were normal. What
might be going on?

121

ANSWER 61
The ECG shows:
• Narrow complex rhythm at 110/minute
• One P wave per QRS complex – sinus tachycardia
• Normal PR interval
• Normal axis
• Normal QRS complexes

Clinical interpretation
The most common causes of a sinus tachycardia are exercise and anxiety, but this
patient was losing weight, and although he was anxious it is necessary to think
about other diagnoses. His diastolic blood pressure was high, which should not
happen with anxiety. He was not thyrotoxic but there must have been some other
physical cause of his problems – it turned out he had a phaeochromocytoma.
Summary
Sinus tachycardia.

See p. 57, 8E

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ECG 62

ECG 62

A 70-year-old man is sent to the clinic because of rather vague attacks of dizziness, which occur approximately
once per week. Otherwise he is well, and there are no abnormalities on examination. Does this ECG help with
his management?

123

ANSWER 62
The ECG shows:
• Sinus rhythm, rate 94/min
• PR interval at the upper limit of normal (200 ms)
• Left axis deviation
• QRS complex duration prolonged (160 ms)
• RSR1 pattern in leads V1–V2; wide S wave in lead V6
• Inverted T waves in leads VL, V1–V4

Clinical interpretation
The left axis deviation is characteristic of left anterior hemiblock. There is also right
bundle branch block (RBBB), so two of the main conducting pathways are blocked,
resulting in ‘bifascicular block’. The fact that the PR interval is at the upper limit
of normal raises the possibility of delayed conduction in the remaining pathway; if
the PR interval were definitely prolonged, this would indicate ‘trifascicular block’.

What to do
Bifascicular block is not an indication for pacing if the patient is asymptomatic. The
problem here is to decide if the attacks of dizziness are due to intermittent complete
heart block. Ideally an ECG would be recorded during an attack – since they occur
only every week or so, ambulatory ECG recording may not be helpful, but an event
recorder would be worth trying. In the absence of clear evidence, the decision
whether or not to insert a permanent pacemaker is a matter of judgement, but in a
patient with this story and ECG it would be a perfectly reasonable thing to do.
Summary
Left anterior hemiblock and RBBB – bifascicular block.

See p. 51, 8E

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ECG 63

ECG 63

This ECG was recorded from a 25-year-old black professional footballer. What does it show, and what would
you do?

125

ANSWER 63
The ECG shows:
• Sinus rhythm, rate 61/min
• Normal axis
• Normal QRS complexes
• Widespread T wave inversion, particularly in leads V2–V5

Clinical interpretation
Repolarization (T wave) abnormalities are quite common in black people, but
alternative explanations for this ECG appearance would be a non-ST segment
elevation myocardial infarction, or a cardiomyopathy.

What to do
This man is a professional football player, so it is important to exclude hypertrophic
cardiomyopathy, and this can be done by echocardiography. Because his career
depended upon coronary disease being excluded, a coronary angiogram was performed and was entirely normal.
Summary
Widespread T wave inversion, probably normal in a black man.

See p. 124, 8E

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ECG 64

ECG 64

II

I

II

III

These ECGs were recorded from a 20-year-old man who had had attacks of a fast and irregular heartbeat for
several years. The upper trace was recorded when he was asymptomatic; the lower trace (rhythm strips only)
was recorded during one of his attacks. What is the diagnosis and what would you do next?

127

ANSWER 64
The upper ECG shows:
• Sinus rhythm, rate 51/min
• Very short PR interval
• Normal axis
• Bizarre and widened QRS complexes with a slurred upstroke (delta wave), best
seen in leads I and V4–V6
The lower ECG shows:
• A very irregular tachycardia with a ventricular rate of up to 200/min
• No visible P waves
• A few normal complexes, but the majority are wide and have a slurred upstroke

Clinical interpretation
This is the Wolff–Parkinson–White (WPW) syndrome: the accessory pathway is on
the right side, and this is sometimes called ‘type B’. The irregular tachycardia is due
to atrial fibrillation.

What to do
Atrial fibrillation in the WPW syndrome can lead to sudden death due to ventricular
fibrillation, so ablation of the abnormal pathway is needed urgently. Immediate
treatment of the atrial fibrillation should be by cardioversion if there is haemo­
dynamic compromise; otherwise flecaidine can be used. Digoxin, verapamil and
diltiazem should be av