ECGs by example

Introduction viiAn approach to the ECG viii Acknowledgements x Section 1 Supraventricular rhythms 2 Normal sinus rhythm with a normal Section 2 Ventricular rhythms 27 Ventricular tachyc

ECGs by Example

For Elsevier

Senior Commissioning Editor : Laurence Hunter Development Editor : Carole McMurray Project Manager : Cheryl Brant

Designer : Charles Gray

Illustration Manager: Gillian Richards

Dean Jenkins Stephen Gerred

Honorary Consultant Physician Consultant Gastroenterologist

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Notices

Knowledge and best practice in this field are constantly

changing As new research and experience broaden our

understanding, changes in research methods, professional

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Introduction vii

An approach to the ECG viii

Acknowledgements x

Section 1 Supraventricular rhythms

2 Normal sinus rhythm with a normal

Section 2 Ventricular rhythms

27 Ventricular tachycardia – atrioventricular

32 Polymorphic ventricular tachycardia –

‘torsade de pointes’ 67

Section 3 Bundle branch block

41 Right bundle branch block with left anterior

hemiblock (bifascicular block) 87

42 Right bundle branch block with

left anterior hemiblock and long PR interval (‘trifascicular’ block) 89

Section 4 Heart block

45 Second degree heart block – Mobitz type 1

49 Third degree heart block – wide complex

56 Polymorphic VT with cardioversion and

pacing by an implantable cardioverter defibrillator (ICD) 121

Section 6 Ischaemic heart disease

59 Myocardial ischaemia – non-specific

65 Very early acute inferior myocardial

infarction 141

67 Acute posterior myocardial

infarction 145

68 Acute anterior myocardial infarction in the

presence of left bundle branch block 147

Section 7 Hypertrophy patterns

73 Left ventricular hypertrophy (LVH) - limb lead

78 Hyperkalaemia (extreme ECG

features) 171

Section 9 Technical issues

86 Regular skeletal muscle

interference 189

Section 10 Miscellaneous

‘Real ECGs on the ward never look like the

diagrams I’ve seen in textbooks.’

‘I’ve read and understood the ‘The ECG

Made Easy’ but I still get lost when

confronted with the real thing.’

These are typical of the comments we have

heard when trying to teach

electro-cardiography to medical students, nurses,

paramedics, or junior doctors They are the

reason why we have written this book They

are the reason why this book is different.

If you’ve read and understood an

introductory ECG book, such as John

Hampton’s “The ECG Made Easy”, but still

get fazed by the real thing when it confronts

you in the Emergency Department or on the

ward, then this book is for you All the

examples are actual ECG recordings as they

would appear in everyday practice Each

recording is at standard speed and size;

25 mm/sec, 1 cm/mV We have endeavoured

to include as many as possible of the

commonly encountered abnormalities as well

as some less common ECG findings which

are of clinical importance This third edition

sees the addition of several new cases as

well as a number of updated cases The

content is based on a joint report by the

American College of Physicians, American

College of Cardiology and the American

Heart Association (Fish C et al 1995 Clinical competence in electrocardiography Journal

of the American College of Cardiologists 25(6): 1465-1469) This report lists the electrocardiographic features that a competent physician should be able to recognise.

How to use this book

Each individual case consists of a full size ECG with a brief sentence summarising the patient’s clinical presentation Below each ECG there is a critique starting with a list of diagnostic features, then a full report of the ECG and any other clinical details that may be important On most pages there is also a box

of common causes or associations There are also a number of relevant radiological images You may wish to read the book as a text, use

it to test yourself and others, or simply use it for reference purposes.

Becoming competent at interpreting real ECGs depends on seeing as many examples

as possible and discussing them with a senior colleague You may wish to use this book as a guide to building a comprehensive ECG collection of your own.

Stephen Gerred

viii AN APPROACH TO THE ECG

We are not going to expand a method for

the systematic interpretation of the

electrocardiogram as this has been done in

many other ECG books This book is about

the ECG in the context of everyday practice

-giving examples of how it appears in the

clinic or on the ward round We’d like to

share a practical approach to the ECG in

clinical practice so that it can be used to its

best advantage.

First you need to remember to use the ECG

It is a tool that can be overlooked especially

when it has been taken, as a matter of routine,

by someone else in the clinical team before you

have even seen the patient As a bedside

instrument that is available in many healthcare

settings it can be very useful in making a

clinical diagnosis Situations where it may be

overlooked are those that are not obviously

cardiac Look at the systemic disorders and

drug effects [Section 8] and the miscellaneous

[Section 10] parts in this book for many

example of how an ECG can help clinch a

diagnosis or management plan In general it is

a tool that has high specificity but low

sensitivity The ECG often confirms a diagnosis

but it is not soo good at excluding a diagnosis.

This is discussed in particular in the section on

hypertrophy patterns [Section 7] Screening for

left ventricular hypertrophy is better achieved

by the use of echocardiography however,

where the diagnostic criteria are present on

the ECG, it can identify cases accurately.

The ECG is the best bedside tool for cardiac arrhythmias and the investigation of

suspected acute coronary syndromes but even in these cases remember to request an ECG, or record one yourself and,

importantly, multiple copies of the ECG when the clinical circumstances change, a procedure is performed, or the existing ECGs are not diagnostic It is better to have multiple ECGs that can be archived in the patient’s notes than to be wishing that one had been taken at a certain point in the past.

In the acute setting you need to be tactical with the use of the ECG Sometimes it is better to have a poor recording, or just the printout from a monitoring chest lead [page 67 for torsade des pointes VT], when other clinical circumstances prevent the careful recording of a 12-lead ECG

Rhythm and morphology aren’t always necessary to have at the same time

Acute medicine is often about judging priorities.

Assuming that a good 12-lead recording is required then the best way to prepare for interpretation is to start by taking the recordings yourself They don’t take long to

do and, with practice, you can take the history from the patient as your setting up the electrodes saving time and building a rapport with your patient.

Angle of Louis

Mid clavical line

Mid axillary line Anterior axillary line

– both ankles and both wrists

– V1 right 4th intercostal space at the

sternum

– V2 left 4th intercostal space at the sternum

– V3 halfway between V2 and V4

– V4 at the apex beat (5th intercostal space,

midclavicular line)

– V5 anterior axilliary line (same level as V4) – V6 mid axilliary line (same level as V4) See the section on technical issues [Section 9] for details of common problems that may occur with the recording of an ECG.

Acknowledgements – First Edition

Our special thanks go to Dr Hugh McAlister,

Cardiologist and Electrophysiologist, and

Dr Hamish Charleson, Cardiologist, both of

Waikato Hospital, Hamilton, New Zealand.

Without their help and guidance this book

would not have been possible.

We would also like to thank all those who

have helped us in the search of the more

elusive recordings particularly: Dr Marjory

Vanderpyl, Accident and Emergency

Department, Waikato; Mrs Carol Rough,

ECG technician, Waikato; Dr David Nicholls,

Wellington, New Zealand; Dr Gowan

Creamer; Dr Walter Flapper, Auckland;

Dr Yadu Singh, Senior Cardiology Registrar,

Waikato Hospital; Dr Michael Beltz, Assistant

Professor of Internal Medicine, Medical

College of Virginia; Dr Peter Williams,

Rheumatologist, Newport, Wales; and the

staff of the Coronary Care Units at Waikato

Hospital, New Zealand and the Royal Gwent

Hospital, Wales We would also like to thank

Mr Andrew Gerred for his help with the

software and hardware required to produce

this book We want to thank all the readers of

the Internet newsgroups sci.med and

sci.med.cardiology and the visitors to our

12-lead ECG website (www.ecglibrary.com) for their support.

Finally, we would like to dedicate the book to Clare and Susan for tolerating our ‘hot air’.

Acknowledgements – Second Edition

We would like to thank all those who provided the new ECGs for this edition, particularly the cardiologists and nursing staff

of the Coronary Care Unit, Middlemore Hospital, New Zealand Special thanks to

Dr Carl Horsley for providing case 76, to

Dr Tim Sutton for case 90 and to Dr Mick Bialas for case 94 We are grateful to Dr Phil Weeks and Dr Graeme Anderson for their help with the radiology The second edition is dedicated to the next generation that will have to endure our ‘hot air’, namely: Harry, Molly and Laurie Jenkins and Christopher Gerred.

Acknowledgements – Third Edition

We would like to acknowledge our publishers

at Elsevier for their continued hard work to support us and develop this third edition, and

to make it relevant to all those working in clinical areas where ECG interpretation is required

x

Normal sinus rhythm Normal sinus rhythm with a normal U wave

Sinus arrhythmia (irregular sinus rhythm)

Sinus tachycardia Sinus bradycardia Atrial bigeminy Atrial trigeminy Ectopic atrial rhythm Multifocal atrial tachycardia Atrial fibrillation

Atrial fibrillation with rapid ventricular response Atrial fibrillation and bundle branch block

Atrial flutter Atrial flutter with 2:1 AV block Atrial flutter with variable

AV conduction Accelerated junctional rhythm Junctional bradycardia Paroxysmal SVT – AV nodal re-entry tachycardia Paroxysmal SVT – AV reciprocating tachycardia (orthodromic)

AV reciprocating tachycardia (antidromic)

Wolff–Parkinson–White syndrome with atrial fibrillation

Supraventricular tachycardia with aberrant conduction Sick sinus syndrome

SUPRAVENTRICULAR

RHYTHMS

Normal sinus rhythm •Ther

Baseline wander: –poor electr

Poor print quality: –pr

Normal sinus rhythm with a normal U wave

CASE 2

CLINICAL NOTE U waves ar

Inverted U waves: –ischaemic heart disease –left ventricular volume overload

Sinus arrhythmia (irr

strip (Fig 3.1) and longer P–P intervals at the end of the rhythm strip (Fig 3.2)

CLINICAL NOTE The cycle length is shorter (and the rate is faster) with inspiration Associations of sinus arrhythmia ➔

Seen in normal individuals: –especially the young or athletic

CLINICAL NOTE This man was on a beta blocker

Atrial bigeminy •An atrial pr

the pause after the ectopic beat is not a full compensatory pause

CLINICAL NOTE If an APB occurs early in the car

result the APB QRS complex will have a RBBB (most common) or LBBB morphology

Atrial trigeminy •An atrial pr

Ectopic atrial rhythm

Multiple pacemakers outside the sinoatrial node •Irr

At rates below 100 b.p.m this rhythm is often called ‘wandering atrial pacemaker’ FEA

CLINICAL NOTE •Multifocal atrial tachycar

CLINICAL NOTE This lady was taking digoxin, 125 micr

Atrial fibrillation with rapid ventricular r

CLINICAL NOTE This lady had par

Atrial fibrillation and bundle branch block •Absent P waves and an irr

initial r waves in all the inferior limb leads excluding inferior infar

Atrial flutter •A characteristic sawtooth waveform seen in the inferior leads (flutter line) of a rapid atrial rate at 250–350 b.p.m. Usually the atrial impulses ar

Atrial flutter with 2:1 A

of block •What gives it away is the rate of ar

CLINICAL NOTE This lady had tr

Obvious flutter line: –inferior leads and lead V1 –ECG tur

Atrial flutter with variable A

Accelerated junctional rhythm •QRS morphology same as sinus rhythm morphology but no pr

CLINICAL NOTE This lady has evidence of a dif

A 73-year

A sequence of thr

less than 60 b.p.m •QRS complexes ar

Junctional escape beats: –narr

CASE 18

CLINICAL NOTE The ECG after tr

CLINICAL NOTE After tr

short PR interval, wide QRS complexes similar to those during tachycar

Atrial fibrillation may be conducted rapidly to the ventricles when an accessory pathway is pr

'pure' delta wav

Supraventricular tachycar

conduction: •the same morphology in tachycar

CLINICAL NOTE Adenosine was given and the rhythm converted to sinus rhythm with incomplete RBBB (Fig 22.3) This suggests a diagnosis of par

Sick sinus syndr

abnormalities including: •spontaneous sinus bradycar

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Ventricular premature beat (VPB)

Ventricular bigeminy Accelerated idioventricular rhythm

Ventricular tachycardia – atrioventricular dissociation Ventricular tachycardia – capture and fusion beats Ventricular tachycardia – morphology of VPB Ventricular tachycardia – myocardial infarction Polymorphic ventricular tachycardia

Polymorphic ventricular tachycardia – ‘torsade de pointes’

Ventricular flutter Ventricular fibrillation (VF)

VENTRICULAR

RHYTHMS