Electrocardiography In Ischaemic Heart Disease Clinical And Imagine Correlations And Prognostic

BLUK094-Bayes September 11, 2007 7:39

The Surface
Electrocardiography
in Ischaemic Heart
Disease

i


The Surface
Electrocardiography
in Ischaemic Heart
Disease
CLINICAL AND IMAGING
CORRELATIONS AND
PROGNOSTIC IMPLICATIONS

A. Bayés de Luna, MD, FESC, FACC
Director of Cardiac Dep. Hospital Quiron, Barcelona
Professor of Medicine, Universidad Autonoma Barcelona
Director of Institut Catala de Cardiologia
Hospital Santa Creu I Sant Pau
St. Antoni M. Claret 167
ES-08025
Barcelona
Spain

M. Fiol-Sala, MD
Chief of the Intensive Coronary Care Unit
Intensive Coronary Care Unit
Hospital Son Dureta
Palma
Mallorca
Spain

With the collaboration of A. Carrillo† , D. Goldwasser* , J. Cino* ,
A. Kotzeva* , M. Riera† , J. Guindo* and R. Baranowski*
∗ From the Institut Catala de Cardiologica, Hospital Santa Creu I Sant Pau, Barcelona, Spain
† From the Intensive Coronary Care Unit, Hospital Son Dureta, Palma, Mallorca, Spain

iii


C 2008 A. Bay´ s de Luna and M. Fiol-Sala
e
Published by Blackwell Publishing
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First published 2008

1 2008

ISBN: 978-1-4051-7362-9

Library of Congress Cataloging-in-Publication Data
Bay´ s de Luna, Antonio.
e
The surface electrocardiography in ischemic heart disease : clinical and imaging
correlations and prognostic implications / A. Bay´ s de Luna, M. Fiol-Sala.
e
p. ; cm.
Includes bibliographical references and index.
ISBN 978-1-4051-7362-9
1. Coronary heart disease–Diagnosis. 2. Electrocardiography. I. Fiol-Sala, M. (Miguel)
II. Title.
[DNLM: 1. Myocardial Ischemia–diagnosis. 2. Electrocardiography–methods. WG 300 B357s 2007]
RC685.C6B36 2008
616.1 2307543–dc22
2007005641
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iv


Contents

Foreword by G¨ nter Breihardt, vi
u 7 Patients with acute chest pain: role of the
ECG and its correlations, 199
Foreword by Elliott M. Antman, vii
8 Acute coronary syndrome: unstable angina
Introduction, ix
and acute myocardial infarction, 209
Part I The ECG in different clinical 9 Myocardial infarction with Q wave, 275
settings of ischaemic heart disease:
10 Myocardial infarction without Q waves
correlations and prognostic
or equivalent: acute and chronic phase, 289
implications, 1
11 Clinical settings with anginal pain, outside
1 Anatomy of the heart: the importance
the ACS, 297
of imaging techniques correlations, 3
12 Silent ischaemia, 302
2 Electrocardiographic changes secondary to
myocardial ischaemia, 19 13 Usefulness and limitations of the ECG in chronic
ischaemic heart disease, 304
3 Electrocardiographic pattern of ischaemia:
T-wave abnormalities, 30 14 The ECG as a predictor of ischaemic
heart disease, 308
4 Electrocardiographic pattern of injury:
ST-segment abnormalities, 55 References, 310
5 Electrocardiographic pattern of necrosis: Index, 325
abnormal Q wave, 128
Colour plate, facing page 12
Part II The ECG in different clinical
settings of ischaemic heart disease:
correlations and prognostic
implications, 195

6 Acute and chronic ischaemic heart disease:
deﬁnition of concepts and classiﬁcation, 197

v


Foreword by G¨ nter Breihardt
u

It is a great pleasure and honour for me to present of still used classifications and correlations but they
this foreword to this new and exciting book. also present solutions to these problems based on
Until recently, correlations between the ECG and recent anatomic–electrocardiographic correlations.
the structural changes of the heart have relied on ex- Their presentation is based on the recent pioneering
perimental studies and on studies done at autopsy, work, initiated by Antoni Bay´ s de Luna, on the use
e
and only to a limited degree on modern imaging of magnetic resonance imaging and its correlations
techniques. When invasive coronary angiography with the ECG.
came into broad use, the general interest shifted This book deserves the attention of all those who
away from the simple tool of the ECG that was con- take care of the ever-increasing number of patients
sidered as low technology, leading to a gradual de- with ischaemic heart disease. It is a treasure and
cline in interest in and knowledge of the ECG in a must for everyone who is involved in manag-
ischaemic heart disease. This is in contrast to what ing patients with ischaemic heart disease, be it as
has happened over many years in the field of ar- practitioner, internist, cardiologist or as intensive
rhythmias where there has been a continuing learn- care physician or interventionalist, as teacher or
ing process with increasingly better interpretation as student – all will benefit from the vast experi-
of arrhythmias based on more and more sophisti- ence of the authors and from the information from
cated invasive electrophysiological studies. their own studies and the literature that they have
Fortunately, some prominent and expert clinical assembled.
researchers have kept their interest in the ECG alive. The reader and eager student of this book will
Among them is Antoni Bay´ s de Luna who, jointly
e appreciate that the most important messages of each
with Miquel Fiol Sala, now can be congratulated chapter are summarised in a box that emphasises the
for the present book on clinical and imaging corre- didactic claim of this work.
lations and the prognostic implications of the sur- This book has the potential to become the ‘bible’
face ECG in ischaemic heart disease. Both authors in this field for generations to come, hopefully
rightly state that they are authors and not editors of worldwide.
a multi-author book. Look at the result: This book
has a quite homogenous and unified presentation G¨ nter Breithardt, MD, FESC, FACC, FHRS
u
which can only be achieved if there is a common Professor of Medicine (Cardiology)
genius behind it. Head of the Department of Cardiology
The aim of this book is to present better cor- and Angiology; and
relations between the structure of the heart, its Head of the Department of
various walls, especially those of the left ventricle, Molecular Cardiology of the
and their relationship with the torso. This will help Leibniz-Institute for Arteriosclerosis Research,
to eliminate much of the confusion in the inter- Westphalian Wilhelms – University of M¨ nster,
u
pretation of the ECG and the terms used, which M¨ nster, Germany
u
has arisen over several decades and still continues
today. The authors not only point to the limitations May 2007
M¨ nster, Germany
u

vi


Foreword by Elliott M. Antman

Medical decision-making consists of a five-step pro- bination with Einthovens three limb leads, the six
cess including obtaining a medical history from precordial leads, and the augmented unipolar leads
the patient, selecting the appropriate diagnostic form the 12-lead electrocardiogram recording pat-
tests, interpreting the results of the diagnostic tests, tern as we know it today.
weighing the risks and benefits of additional testing With the passage of time, many new and highly
or potential therapeutic interventions, and agree- sophisticated imaging and biochemical test have
ing on a plan of a therapeutic approach in con- been introduced into clinical medicine. Some might
junction with the patients wishes. A diagnostic test argue that the 12-lead electrocardiogram has lost
that optimizes sensitivity and specificity is partic- some its luster but a more penetrating analysis of
ularly attractive clinically, since it is used to am- the situation shows that this is not the case. The new
plify the prior probability that a particular diag- imaging and biochemical tests amplify and extend
nostic condition is present. Given the escalating our ability to interpret the 12-lead electrocardio-
cost of health care, a diagnostic test is especially gram in ways that we did not realize were possible
attractive if it is inexpensive. Diagnostic tests that in the past.
contain these features and utilize equipment that One of the most important applications of the
is universally available are more likely to stand the surface electrocardiogram is in evaluation of pa-
test of time in clinical medicine. One such diag- tients with ischemic heart disease. This elegant text-
nostic test – the electrocardiogram – stands out as book by Drs. A. Bayes de Luna and M. Fiol-Sala is
a shining example of a successful diagnostic test. a refreshing modernistic look at the surface elec-
It is a well accepted component of the diagnos- trocardiogram by two internationally recognized
tic toolbox of health care professionals around the experts in the field. They provide the reader, in
world. a single volume, a richly illustrated resource that
Einthoven is often credited as the individual integrates clinical findings, contemporary imaging
who introduced the electrocardiogram to clinical modalities, cutting edge biomarker findings with
medicine. After applying a string galvanometer to a 100-year old diagnostic test – the 12-lead sur-
record the hearts electrical signals on the surface of face electrocardiogram. The book is divided into
the body, it was in 1895 that he introduced the five two parts. First, electrocardiographic patterns of is-
deflections P, Q, R, S, and T. Willem Einthoven was chemia, injury, and infarction are discussed. Polar
honored in 1924 for his invention of the electro- maps, vectorial illustrations, and simple diagrams
cardiograph by receiving the Nobel Prize in Phys- illustrating the relationship between myocyte ac-
iology or Medicine. In 1934, Frank Wilson intro- tion potentials and the surface electrocardiogram
duced the concept of unipolar leads, and in 1938 are appealing for both the novice and experienced
the American Heart Association and Cardiac Soci- reader. The second part of the book explores the
ety of Great Britain defined the standard positions use of the surface electrocardiogram in a variety of
and wiring of the chest leads V1–V6. In 1942, Gold- clinical settings of ischemic heart disease, touching
berger introduced the technique for increasing the on the correlations with coronary anatomy and the
voltage of Wilsons unipolar leads, thus creating the prognostic implications that can be gleaned from
augmented limb leads aVR, aVL, and aVF. In com- the ECG.

vii


viii Foreword

This textbook by Bayes de Luna and Fiol Sala is Elliott M. Antman
a marvelous example of what can be accomplished Senior Investigator, TIMI Study Group
when clinicians who are comfortable at the patient’s Professor of Medicine, Harvard Medical School; and
bedside also have the visionary insight to incor- Director of the Samuel A. Levine Cardiac Unit
porate new knowledge from contemporary cardiac at the Brigham & Women’s Hospital
imaging procedures into a fresh view of an older, Cardiovascular Division
but still extremely useful, diagnostic test. As with Brigham & Women’s Hospital
the classical 12-lead electrocardiogram itself, read- Boston
ers of this textbook will ﬁnd themselves returning USA
to it over and over again because of the depth and
breadth of its clinical usefulness. May 2007
Boston, USA


Introduction

The electrocardiogram (ECG), which was discov- helps to stratify the risk and, consequently, to take
ered more than 100 years ago and has just celebrated the most appropriate therapeutic decision.
its first century, appears to be more alive than ever. In the chronic phase of Q-wave infarction, the
Until recently its utility was especially important ECG is also very useful, since the identification of
for identifying different ECG morphological abnor- different ECG patterns of infarction permits us to
malities, including arrhythmias, blocks at all levels, have a reliable approximation of the infarcted area.
pre-excitation, acute coronary syndromes, as well Lastly, the ECG is of great importance, as the
as Q-wave acute myocardial infarction, for which number of patients with IHD is very large, and
ECG was the ‘gold-standard’ diagnostic technique. therefore the repercussion to properly understand
An authentic re-evaluation of ECG has been evi- the ECG changes may have an extraordinary social
denced in the last years as a result of the great impor- and economic impact.
tance it acquired in the risk stratification and prog- Nevertheless, in spite of all above-mentioned ar-
nosis of different heart diseases. Every year there is guments, there are few books that have dealt in a
more and more information that demonstrates that global manner with the value of ECG in IHD. Over
ECG provides new and important data, and its ap- 30 years ago Schamroth and Goldberger wrote two
plications are growing and will be expanded in the important works, dedicated more to the chronic
future. It has been recently confirmed that ECG al- phase of IHD, which have inevitably become out-
lows us to approach with high reliability the molec- dated in many aspects. More recently, two groups,
ular mechanisms that explain some heart diseases, those of Wellens and Sclarovsky, which have pub-
such as chanellopathies. For example, the correla- lished pioneer studies on the importance of the ECG
tion between ECG changes and the genes involved in the acute phase of IHD, have published two excel-
in long QT syndrome is well known. lent books that brilliantly deal with the ECG’s role
Although the usefulness of the surface ECG is im- in the acute phase of this disease. We nevertheless
portant in all types of heart diseases, it stands out considered that in the overall context of the ECG’s
particularly in the case of ischaemic heart disease importance in IHD there remained a space to fill
(IHD), for various reasons. The ECG is the key di- in this field. That is what we intend to do with this
agnostic tool both in the acute phase of IHD (acute publication.
coronary syndromes, ACSs) and in the chronic one One of the most important and new aspects of
(Q-wave infarction). Furthermore, it is crucial for the book is the great number of correlations not
risk stratification in patients with acute ischaemic only with coronariography but also with echocar-
pain. The ACSs are nowadays divided into two types: diography, isotopic studies and new imaging tech-
with or without ST-segment elevation. This is ex- niques, especially cardiovascular magnetic reso-
tremely important in the decision making to use nance (CMR), and also in some cases with coronary
fibrinolytic therapy. In the case of an ACS, espe- multidetector computer tomography (CMDCT).
cially with ST-segment elevation (STE-ACS), a care- All these correlations have given us a huge amount
ful evaluation of ST-segment deviations in different of important and new information.
leads allows us to ascertain not only the occluded We explain the ECG pattern of chronic Q-wave
artery but also the site of occlusion. Therefore, it myocardial infarction (MI) based on the correlation

ix


x Introduction

with the VCG loops. We consider that the ECG-VCG understand the ECG curves generated during acute
correlation is the most didactic way to explain ECG and chronic ischaemia.
(Bayes de Luna 1977, 1999). However, we only com- In the second part we explain a detailed global
ment in this book the ECG criteria for diagnosis of approach that has to be done in patients with acute
chronic-Q wave MI because there is not agreement precordial pain, emphasising on the importance of
supporting that the VCG criteria present better ac- ECG changes, first to diagnose the ischaemic origin
curacy than ECG criteria (Hurd 1981, Warner 1982) and later to stratify the risk in different types of ACS.
T and the use of VCG is more time-consuming and Other electrocardiographic features of ACS, such as
has not become popular in clinical practice. In order coexisting arrhythmias, conduction disturbances,
to set up its real importance could be mandatory in ECG changes following fibrinolytic treatment and
the era of imaging techniques to perform a com- mechanical complications and the ECG character-
parative study of ECG and VCG criteria with the istics of atypical ACSs, are also presented. Further-
standars of cardiovascular magnetic resonance. more, we comment on the new, current concepts
When necessary, we also comment on the of MI with and without Q wave, the ECG mark-
role of other non-invasive electrocardiographic ers of poor prognosis in chronic IHD and the ECG
techniques, especially exercise ECG and Holter characteristics of other clinical settings with angi-
monitoring. Just a few remarks are given on other nal pain outside the acute phase of ACS as chronic
non-invasive electrocardiological techniques. The stable angina, X syndrome, silent ischaemia, etc.
invasive electrophysiological techniques are usu- Finally, the capacity of ECG as marker of IHD is
ally not useful for risk stratification but are nec- also discussed.
essary in case of resynchronisation and implantable The information given in this book may help to
cardioverter-defibrillator implantation or ablation perform the best diagnosis in patients with acute
procedures. thoracic pain and to take decisions, sometimes in
We have two parts in this book. In the first one, an urgent manner, for the best approach of manage-
following comments on the most important as- ment in patients with acute and chronic IHDs. We
pects of the heart’s anatomy related to IHD on would like to emphasise that we are not the editors,
the basis of coronariographic and imaging correla- but the authors of the book. This is important, be-
tions, we discuss the concept of the ECG patterns of cause all the information is given in a homogeneous
ischaemia, injury and infarction, the electrophysio- manner, without the presence of contradictory
logical mechanisms that explain them and the cor- opinions that often appear in ‘edited’ books. Also,
relation that exists between the presence of these the presence of frequent cross-references within the
patterns in different leads and the myocardial area text makes the content of the book easier to fol-
involved. Correlations between ECG curves and low. We are aware that we are often repetitive, es-
vectorcardiographic loops constitute the key to un- pecially when we comment on the new concepts of
derstand the ECG morphologies. For this reason, ACS with or without STE and the new classification
the two above-mentioned techniques of electrical of Q-wave MI based on CMR correlations. How-
activity recording are often represented together in ever, we consider that this may be helpful especially
this book. Nevertheless, in clinical practice the sur- for the readers who are not too much involved in
face ECG alone allows for making a correct diag- the topic and also for consultants of some specific
nosis in most cases. Of particular interest is the topic.
possibility to locate the place of coronary occlu- We express our gratitude to E. Antman, pioneer
sion in patients with STE-ACS, thanks to the ap- in many aspects of IHD, who has written a gen-
plication of sequential algorithms, and to identify erous Foreword to this book, for his support and
the typical and atypical ECG patterns of STE-ACS, collaboration. We have written together a mono-
and to define properly the classification of non (N) graph related to the role of surface ECG in patients
STE-ACS. Also important is the new classification of with acute thoracic pain and ST-segment elevation
infarction in case of Q-wave MI based on our ex- MI, which has been mostly included in this book,
perience with contrast-enhanced (CE)-CMR cor- and for that he may also be considered co-author of
relations. All this represents a new approach to the book. Also my thanks to G¨ nter Breithardt, an
u


Introduction xi

expert and pioneer in electrocardiology, because he E. Rodriguez, P. Torner, T. Anivarro, M.T. Subirana
has also written an outstanding Foreword empha- and X. Vi˜ olas, who collaborated in the selection of
n
sising the electrocardiographic aspects of the book. iconography and in many other aspects. A special
We also appreciate very much the advice and friend- mention of gratitude to the Cardiovascular Imag-
ship of Y. Birnbaum, J. Cinca, P. Clemensen, A. ing Unit of Saint Paul Hospital (G. Pons, F. Car-
Gorgels, K. Nikus, O. Pahlm, G. Pohost, W. Roberts, reras, R. Leta and S. Pujadas) for its outstanding
S. Sclarovsky, S. Stern, G. Wagner, H. Wellens and contribution with the CMR and CMDCT ﬁgures.
W. Zareba, with whom we shared many aspects of Many thanks also to Montserrat Saur´, who gave
ı
´
the new ideas expressed in this book. us her valuable secretarial support; to Josep Sarrio
Finally, we would like to thank the help espe- for some of the drawings; and to Prous Science and
cially of J. Cino, A. Carrillo, A. Kotzeva, M. Riera, J. Blackwell Publishing for their invaluable work in all
Guindo, D. Goldwasser and R. Baranowski for their the printing process of the book in its Spanish and
collaboration, and also of T. Bay´ s-Gen´s, A. Boix,
e ı English versions.
R. Elosua, P. Farres, J. Guerra, A. Martinez Rubio,
Antoni Bay´s de Luna
e
´
J. Gurri, M. Santalo, J. Puig, I. Ramirez, J. Riba,
Miquel Fiol-Sala

BLUK094-Bayes August 20, 2007 12:47

I PART I
Electrocardiographic
patterns of ischaemia,
injury and infarction


1 CHAPTER 1

Anatomy of the heart: the
importance of imaging techniques
correlations
The surface electrocardiography (ECG) in both state of the coronary tree, because the revascu-
acute and chronic phase of ischaemic heart dis- larisation treatment has modified, sometimes very
ease (IHD) may give crucial information about the much, the characteristics of the occlusion respon-
coronary artery involved and which is the area of sible for the MI. Furthermore, the catheterisa-
myocardium that is at risk or already infarcted. tion technique may give important information for
This information jointly with the ECG–clinical cor- identifying hypokinetic or akinetic areas. The latter
relation is very important for prognosis and risk may be considered comparable to infarcted areas
stratification, as will be demonstrated in this book. (Shen, Tribouilloy and Lesbre, 1991; Takatsu et al.,
Therefore, we will give in the following pages an 1988; Takatsu, Osugui and Nagaya, 1986; Warner
overview of the anatomy of the heart, especially the et al., 1986). Currently, in some cases, the non-
heart walls and coronary tree, and emphasise the invasive coronary multidetector computer tomog-
best techniques currently used for its study. raphy (CMDCT) may be used (Figure 1.1).
For centuries, since the pioneering works of The era of modern non-invasive imaging tech-
Vesalio, Leonardo da Vinci, Lower and Bourgery- niques started with echocardiography, which is
Jacob, pathology has been a unique method to study very easy to perform and has a good cost-effective
the anatomy of the heart. Since the end of the nine- relation. This technique plays an important role, es-
teenth century, the visualisation of the heart in vivo pecially in the acute phase, in the detection of left-
has been possible by X-ray examination. The last ventricular function and mechanical complications
40–50 years started the era of invasive imaging tech- of acute MI (Figures 1.2, 8.28 and 8.29). Also, it is
niques with cardiac catheterisation (angiography very much used in chronic ischaemic-heart-disease
and coronary angiography) and modern non- patients for the study of left-ventricular function
invasive imaging techniques, first with echocardio- and also detection of hypokinetic and akinetic areas
graphy and later with isotopic studies, scanner (Bogaty et al., 2002; Matetzky et al., 1999; Mitamura
and cardiovascular magnetic resonance (CMR). et al., 1981). However, echocardiography tends to
These techniques open a new avenue to study not overestimate the area that is at risk or necrosed,
only the anatomy of the heart, coronary arteries and and thus its reliability is good but not excellent.
great vessels but also the myocardial function and The techniques of echo stress and especially iso-
perfusion, and the characterisation of the valves, topic studies (single-photon emission computed
pericardium, etc. tomography, SPECT) have proved to be very re-
The coronary angiography (Figure 1.1) is espe- liable for detecting perfusion defects and necrotic
cially important in the acute phase for diagnosing areas (Gallik et al., 1995; Huey et al., 1988; Zafrir
the disease and correlating the place of occlusion et al., 2004) (Figure 1.3). They are very useful
with the ST-segment deviations. It is also useful in cases where there is dubious precordial pain
in the chronic phase of the disease. However, in with positive exercise testing without symptoms
the chronic phase of Q-wave myocardial infarc- (Figure 4.58). It has been demonstrated, however,
tion (MI) the ECG does not usually predict the that in some cases (non-Q-wave infarction) the

3


4 PART I Electrocardiographic patterns of ischaemia, injury and infarction

(A)

(B)

Figure 1.1 (A) Normal case: coronary angiography (left) coronary angiography). (G) These images show that
and three-dimensional volume rendering of CMDCT (right) CMDCT (a, b) may delimitate the length of total occlusion
showing normal LAD and LCX artery. The latter is partially and visualise the distal vessels (see arrows in (b), the yellow
covered by left appendix in CMDCT. The arrow points out ones correspond to distal RCA retrograde flow from LAD)
LAD. (B) Normal case: coronary arteriography (left) and that is not possible to visualise with coronary angiography
three-dimensional volume rendering of CMDCT (right) (c). (H) A 42-year-old man sports coach with a stent
showing normal dominant RCA. (C) 85-year-old man with implanted in LAD by anginal pain 6 months before. The
atypical anginal pain: (a) Maximal intensity projection patient complains of atypical pain and present state of
(MIP) of CMDCT with clear tight mid-LAD stenosis that anxiety that advises to perform a CMDCT to assure the
correlates perfectly with the result of coronary good result and permeability of the stent. In the MIP of
angiography performed before PCI (b). (D) Similar case as CMDCT (a–c) was well seen the permeability of the stent
(C) but with the stenosis in the first third of RCA ((a–d) but also a narrow, long and soft plaque in left main trunk
CMDCT and (e) coronary arteriography). (E) Similar case as with a limited lumen of the vessel (see (d) rounded circle)
(C) and (D) but with the tight stenosis in the LCX before that was not well seen in the coronary angiography (e) but
the bifurcation ((a) and (b) CMDCT and (c) coronary was confirmed by IVUS (f). The ECG presents not very deep
angiography). (F) These images show that CMDCT may also negative T wave in V1–V3 along all the follow-up. This
demonstrate the presence of stenosis in distal vessels, in figure can be seen in colour, Plate 1.
this case posterior descending RCA ((a–b) CMDCT and (c))

extension of the infarction may be underestimated tion studies of the myocardium, gives us the best ‘in
and that in presence of the left bundle branch block vivo’ anatomic information about the heart. Thus,
(LBBB) the estimation of some perfusion defects is this technique, in conjunction with gadolinium in-
doubtful. jection and contrast-enhanced CMR (CE-CMR),
The most recent imaging techniques are CMR is very useful for identifying and locating MI, as
(Figure 1.4) and CMDCT (Figure 1.1). The latter is well as for determining its transmurality with ex-
used for non-invasive study of coronary tree. CMR, traordinary reliability, comparable to pathological
which may also be used for perfusion and func- studies (Bay´ s de Luna et al., 2006a–c; Cino et al.,
e


CHAPTER 1 Anatomy of the heart: the importance of imaging techniques correlations 5

(C)

(D)

Figure 1.1 (Continued )

The heart walls and their
2006; Moon et al., 2004; Salvanayegam, 2004; Wu
segmentation: cardiac magnetic
et al., 2001). This is why CE-CMR has become the
resonance (Figures 1.4–1.14)
gold-standard technique for studying correlations
between ECG ﬁndings and infarcted myocardial ar- The heart is located in the central-left part of the
eas in the chronic phase of IHD (Bay´ s de Luna
e thorax (lying on the diaphragm) and is oriented an-
et al., 2006a–c; Cino et al., 2006; Engblom et al., teriorly, with the apex directed forwards, and from
2002, 2003). Also, CE-CMR may distinguish ac- right to left (Figure 1.4).
cording to location the hyperenhancement areas be- The left ventricle (LV) is cone shaped. Although
tween ischaemic and non-ischaemic patients (Fig- its borders are imprecise, classically (Myers et al.,
ure 1.5) and may show in vivo the sequence of the 1948a, b; Myers, Howard and Stofer, 1948), it has
evolving transmural MI (Mahrholdt et al., 2005a, been divided, except in its inferomost part the apex,
b) (Figure 8.5). The reproducibility of CE-CMR into four walls, till very recently named septal, ante-
along time, especially after the acute phase, is very rior, lateral and inferoposterior. In the 1940s–1950s
good. It also has the advantage of not producing the inferoposterior wall was named just posterior
radiation. The current limitation of CMR, which (Goldberger, 1953) (Figure 1.6A), probably because
will probably be solved in the next few years, is it was considered opposed to the anterior wall. Later
the study of coronary tree. Currently, this may be on (Perloff, 1964), only the basal part of this wall,
performed non-invasively by CMDCT (see above which was thought to bend upwards, was consid-
Fig 1.1). ered really a posterior wall (Figure 1.6B). Therefore,



(E)

(F)


it was named ‘true posterior’ and the rest of the wall ity of papers (Roberts and Gardin, 1978), ECG
just ‘inferior wall’ (Figure 1.6). According to that, books (Figure 1.7B to D), task force (Surawicz et
for more than 40 years the terms ‘true’ or ‘strict al., 1978) and statements (Hazinsky, Cummis and
posterior infarction’, ‘injury’ and ‘ischaemia’ have Field, 2000).
been applied, when it was considered that the basal Later on, in the era of imaging techniques, the
part of the inferoposterior wall was affected. The heart was transected into different planes (Figure
committee of the experts of the International So- 1.7) and different names were given to the heart
ciety of Computerised ECG (McFarlane and Veitch walls by echocardiographists and experts in nuclear
Lawrie, 1989), in accordance with the publications medicine. However, recently, the consensus of the
of Selvester and Wagner, has named these walls an- North American Societies for Imaging (Cerqueira,
terosuperior, anterolateral, posterolateral and in- Weissman and Disizian, 2002) divided the LV in
ferior, respectively. However, this nomenclature 17 segments and 4 walls: septal, anterior, lateral
has not been popularised, and the classical names and inferior (Figures 1.8 and 1.9). This consensus
(Figure 1.7A) are still mostly used in the major- states that the classical inferoposterior wall should



(G)

(H)


be called inferior ‘for consistency’, and segment 4 we will explain, thanks to correlations with CMR,
should be called inferobasal instead of posterior why we consider that this terminology (Cerqueira,
wall. Therefore the word ‘posterior’ has to be sup- Weissman and Disizian, 2002) is the best and it will
pressed. Figures 1.8 and 1.9 show the 17 segments be used further in this book. Page 16 shows the evo-
into which the four left-ventricular walls are divided lution of the terminology given to the wall that lies
(6 basal, 6 medial, 4 inferior and the apex), and the on the diaphragm.
right side of Figure 1.9 shows the heart walls with If we consider that the heart is located in the
their corresponding segments on a polar ‘bull’s-eye’ thorax in a strictly posteroanterior position, as is
map, as used by specialists in nuclear medicine. Now presented by anatomists and by experts in nuclear



Figure 1.2 Echocardiography: see example of volumes, function analysis: post-infarct lateral wall hypokinesis
wall thickening and myocardium mass in a normal case shown in the four view. The left ventricle is dilated.
and in a patient with post-MI. Above: (A) End-diastolic and Superposition of the traced endocardial contours at end
(B) end-systolic apical long-axis views of a normal left diastole (A) and end systole (B) shows the hypokinesis and
ventricle. The endocardial and epicardial contours are compensatory hyperkinesis of the interventricular septum.
traced and the built-in computer software of the (C) It shows the superimposed end-diastolic and
¨
ultrasound system allows calculation of volumes, wall end-systolic contours. (Adapted from Camm AJ, Luscher TF
thickening and myocardial mass. Below: Segmental wall and Serruys PW, 2006.)

sagittal view of the heart is, in respect to the tho-
medicine, and in the transverse section of CMR
rax, located with an oblique right-to-left inclination
images (Figure 1.10A–C), we may understand that
and not in a strictly posteroanterior position, as was
in case of involvement (injury or infarction) of
usually presented by anatomists, nuclear medicine
basal part of inferior wall (classically called pos-
and the transverse section of CMR (Figure 1.10).
terior wall) especially when in lean individuals the
This helps us to understand how the RS (R) or pre-
majority of inferior wall is placed in a posterior po-
dominant ST-segment depression patterns in V1 is
sition (Figure 1.13C), an RS (R) and/or ST-segment
the consequence of the infarction of or injury to the
depression in V1 will be recorded (Figure 1.10D).
lateral, not the inferobasal, segment (classical poste-
However, now, thanks to magnetic resonance cor-
rior wall) (Figure 1.12). However, we have to remind
relations (Figure 1.11), we have evidence that the

The usefulness of invasive and non-invasive of coronary tree by CMDCT in chronic-heart-
imaging techniques and their correlations with disease patients, will be commented.
r In chronic Q-wave MI we will emphasise the
ECG in IHD:
r Non-invasive imaging techniques, especially importance of the ECG–CMR correlations to
SPECT, are very useful in detecting perfusion de- identify and locate the area of infarction.
r ECG is very useful in coronary care unit and is
fects during exercise test.
r We will present in this book the importance of also used routinely in the chronic phase.
r X-ray examination still plays some role es-
ECG–coronary angiography correlations to iden-
tify the artery occlusion site and the myocardial pecially in the acute phase (heart enlargement
area at risk. and pulmonary oedema) and in the detection
r The role of coronary angiography, and in of aneurysms and calciﬁcations, visualisation of
special circumstances, of non-invasive detection heart valves, pacemakers, etc.



(A)

(B)

Figure 1.3 Examples of correlation exercise test – isotopic HLA) see (A) normal uptake at rest (Re) and during exercise
images (SPECT). (A) Above: Observe the three heart planes (Ex) can be observed. Middle: Abnormal uptake only
(see Figure 1.4B) used by nuclear medicine experts (and during exercise of segments 7, 13 and 17 (see Figure 1.8) in
other imaging techniques) to transect the heart: a patient with angina produced by distal involvement of
(1) short-axis (transverse) view (SA), (2) vertical long-axis not long LAD. The basal part of the anterior wall of left
view (VLA) (oblique sagittal-like) and (3) horizontal ventricle is not involved. Below: Abnormal uptake during
long-axis (HLA) view. Below: Normal case of perfusion of rest and exercise in a patient in chronic phase of MI
left ventricle. On the middle is (B) the bull’s-eye image of produced by distal occlusion of very long LAD that wraps
this case. The segmentation of the heart used in this book the apex involving part of inferior wall (segments 7, 13 and
is shown (Cerqueira, Weissman and Disizian, 2002). On (A) 17 and also 15) (see Figure 1.8), without residual ischaemia
transections of the three axes are shown. The short-axis on exercise. In this case the image of abnormal uptake is
transections is at the mid-apical level (see Figure 1.8 for persistent during rest. See in all cases the ECG patterns that
segmentation). (B) Above: In the three planes (SA, VLA and may be found. This ﬁgure can be seen in colour, Plate 2.



(A)

(B)

Figure 1.4 Cardiac magnetic resonance imaging (CMR). (3) vertical long-axis view (oblique sagittal-like). Check the
(A) Transections of the heart following the classical human great difference between the sagittal plane according to
body planes: (1) frontal plane, (2) horizontal plane and human body planes (A(3)) and the heart planes (B(3). (B) It
(3) sagittal plane. (B) Transections of the heart following shows the four walls of the heart with the classical names:
the heart planes that cut the body obliquely. These are the septal (S), anterior (A), lateral (L) and inferoposterior.
planes used by the cardiac imaging experts: (1) short-axis Currently, the inferoposterior wall is named for consistency
(transverse) view, in this case at mid-level (see B(1)); just inferior (I) (see p. 16 and Figure 1.8).
(2) horizontal long-axis view;

Hyperenhancement patterns
Ischaemic Non-ischaemic

A. Mid-wall HE
A. Subendocardial infarct

. Idioparthi dilared . Hypertrophic . Sarcoidosis
cardiomyopathy cardiomyopathy
. Myocarditis
. Myocarditis . Right ventricular
. Anderson-fabry
pressure overload (e.g.
congenital heart disease, . Chas disease
pulmonary HTN)

B. Epicardial HE

B. Transmular infarct

. Sarcoidosis, myocarditis, Anderson-Fabry, Chags disease

C. Global endocardial HE

. Amyloidosis, systemic selerosis. post-cardiac transplantation

Figure 1.5 Hyperenhancement patterns found in clinical ischaemic disease. Isolated mid-wall or subepicardial
practice. If hyperenhancement is present, the hyperenhancement strongly suggests a ‘non-ischaemic’
subendocardium should be involved in patients with etiology. (Taken from Marhrholdt, 2005.)



heart planes that are perpendicular to each other
Anterior infarct Posterior infarct
(see Figure 1.4B), as has been already done in
nuclear medicine (Figure 1.3; see Plate 2). These
planes transect the heart following the heart planes
(Figure 1.4B) and are the following: horizontal long-
axis view, short-axis view (transverse) and vertical
LV LV
long-axis view (oblique sagittal-like). In reality the
V4
V4
oblique sagittal-like view (Figure 1.11B) presents,
Goldberger, 1953
as we have said, an oblique right to left and not
a strict posteroanterior direction (compare Figure
True posterior infarct
Anterior infarct
1.4A(3) with Figures 1.4B(3) and 1.11B). There-
fore in the presence of infarction of the inferobasal
part of inferior wall (classically called posterior wall)
and especially when the infarction involves the mid-
inferior wall if it is located posteriorly, as happens in
very lean individuals (Figure 1.13C), the vector of
Perloff, 1964
infarction generated in this area is directed forwards
Figure 1.6 Above: The concept of anterior and posterior and from right to left and is recorded as RS mor-
infarction according to Goldberger (1953). Below: The
phology in V2–V3, but not in V1 where it presents
concept of anterior and true or strict posterior infarction is
a normal rS morphology (Figure 1.12B). On the
shown according to Perloff (1964). The other part of the
contrary, the vector of infarction, in the case of in-
wall that lies on the diaphragm became to be named
farction involving the lateral wall, may generate an
inferior (see p. 16).
RS pattern in V1 (Bay´ s de Luna, Batchvarov and
e
Malik, 2006; Bay´ s de Luna, Fiol and Antman, 2006;
e
Cino et al., 2006) (Figure 1.12C) (see legend Figure
that in the majority of cases except for very lean in-
1.12).
dividuals (see Figure 1.13C), the part of the inferior
(c) The longitudinal vertical plane (Figures 1.3(2),
wall that is really posterior just involves the area
1.8C and 1.11B; see Plate 2) is not fully sagittal with
of late depolarisation (segment 4, or inferobasal).
respect to the anteroposterior position of the tho-
Therefore, in case of MI of this area, there would
rax, but rather oblique sagittal, as it is directed from
not be changes in the first part of QRS, because this
right to left. (The sagittal-like axis follows the CD
MI does not originate a Q wave or an equivalent
line in Figure 1.11A.) Compare Figures 1.4B(3) and
wave (Durrer et al., 1970).
1.11B with the true sagittal view – Figure 1.4A(3).
The CMR technique gives us real informa-
The view of this plane, as seen from the left side
tion about the in vivo heart’s anatomy (Blackwell,
(oblique sagittal), allows us to correctly visualise the
´
Cranney and Pohost, 1993; Pons-Llado and Car-
anterior and the inferior heart walls (Figure 1.11B).
reras, 2005) (Figure 1.4). In this regard, the follow-
We can clearly see that the inferior wall has a por-
ing are important:
tion that lies on the diaphragm until, at a certain
(a) CMR patterns of the frontal, horizontal and
point, sometimes it changes its direction and be-
sagittal planes of the heart following the human
comes posterior (classic posterior wall), now called
body planes are shown in Figure 1.4A. This allows
inferobasal segment. This posterior part is more or
us to know with precision the heart’s location within
less important, depending on, among other factors,
the thorax. In this figure we can observe these tran-
the body-build. We have found (Figure 1.13) that in
sections, performed at the mid-level of the heart.
most cases the inferior wall remains flat (C shape)
(b) Nevertheless, bearing in mind the three-
(Figure 1.13B). However, sometimes a clear basal
dimensional location of the heart within the tho-
part bending upwards (G shape) (Figure 1.13A) is
rax, in order to correlate the left ventricular walls
seen. Only rarely, usually in very lean individuals,
amongst themselves and, above all, to locate the
does the great part of the inferior wall present a clear
different segments into which they can be divided,
posterior position (U shape) (Figure 1.13C).
it is best to perform transections following the



(A) (B) (C)

(D)
Frontal view

Inferior Inferoposterior Direct posterior Posterolateral

Figure 1.7 (A) The left ventricle may be divided into four basal part of the wall lying on the diaphragm that was
walls that till very recently were usually named anterior thought to bend upwards. It was considered that the heart
(A), inferoposterior (IP) or diaphragmatic, septal (S) and was located strictly in a posteroanterior position in the
lateral (L). However, according to the arguments given in thorax (Figures 1.10D and 1.12A). The cardiovascular
this book, we consider that the ‘inferoposterior’ wall has magnetic resonance (CMR) gives us the information that
to be named just ‘inferior’ (see p. 16). (B–D) Different the inferoposterior wall lies flat, even in its basal part, in
drawings of the inferoposterior wall (inferior + posterior around two-third of cases (Figure 1.13) and make evident
walls) according to different ECG textbooks (see inside the that the heart is always placed in an oblique position
figure). In all of them the posterior wall corresponds to the (Figure 1.12B,C).

Therefore, often, the posterior wall does not ex- (d) The longitudinal HP (Figures 1.3(3) and 1.8B;
ist and for this reason, the name ‘inferior wall’ see Plate 2) is directed from backwards to forwards
seems clearly better than the name ‘inferoposte- from rightwards to leftwards, and slightly cephalo-
rior’. On the other hand, the anterior wall is, in caudally. In Figure 1.8A (arrows), one can appre-
fact, superoanterior, as is clearly appreciated in ciate how, following the line AB, the heart can be
Figure 1.11B. However, in order to harmonise the opened like a book (Figure 1.8B).
terminology with imaging experts and to avoid (e) The transverse plane (Figures 1.4B(1), 1.3A(1)
more confusion, we consider that the names ‘ante- and 1.8A), with respect to the thorax, is directed pre-
rior wall’ and ‘inferior wall’ are the most adequate dominantly cephalocaudally and from right to left,
for its simplification and also, because when an in- and it crosses the heart, depending on the transec-
farct exists in the anterior wall, the ECG repercus- tion performed, at the basal level, mid-level or apical
sion is in the horizontal plane (HP; V1–V6) and level (Figure 1.8A). Thanks to these transverse tran-
when it is in the inferior wall – even in the infer- sections performed at different levels, we are able to
obasal segment – it is in the frontal plane (FP). view the right ventricle (RV) and the left-ventricular



(A) (B)

(C)

Figure 1.8 (A) Segments into which the heart is divided, performed by the American imaging societies (Cerqueira,
according to the transverse (short-axis view) transections Weissman and Disizian, 2002). (B) View of the 17 segments
performed at the basal, mid and apical levels. The basal with the heart open in a horizontal long-axis view and
and medial transections delineate six segments each, while (C) vertical long-axis (sagittal-like) view seen from the right
the apical transection shows four segments. Together with side. Figure 1.14 shows the perfusion of these segments by
the apex, they constitute the 17 segments in which the the corresponding coronary arteries.
heart can be divided according to the classiﬁcation

Figure 1.9 Images of the segments into which the left six segments each, while the apical transection shows four
ventricle (LV) is divided according to the transverse segments. Together with the apex, the left ventricle can be
transections (short-axis view) performed at the basal, mid divided into 17 segments. Note, in the mid-transection, the
and apical levels, considering that the heart is located in situation of the papillary muscles is shown. To the right, all
the thorax just in a posteroanterior and right-to-left 17 segments in the form of a polar map (bull’s-eye), just as
position. Segment 4, inferobasal, was classically named it is represented in nuclear medicine reports.
posterior wall. The basal and medial transections delineate

(A) (B) (C) (D)

Figure 1.10 (A) The heart, shown out of the thorax by infarction vectors (Inj. V and Inf. V) with the same direction
anatomists and pathologists; (B) bull’s-eye image as it is but different sense may be seen. Compare the differences
shown by nuclear medicine and (C) transverse transection in the transections of the heart presented in Figure
as it is shown by CMR. In both cases the position of the 1.4(above) taking the body as a centre and 1.4(below)
heart is presented as if the heart was located in the thorax taking the heart as a center.
in a strictly posteroanterior position. (D) The injury and



(A) (B)

Figure 1.11 Magnetic resonance imaging. (A) Thoracic from segments 5 and 11 (lateral wall) faces V1 and
horizontal axial plane at the level of the ‘xy’ line of the therefore explains RS morphology in this lead (line BA).
drawing on the right side of the ﬁgure. The four walls can (B) According to the transection, following the vertical
be adequately observed: anterior (A), septal (S), lateral (L) longitudinal axis of the heart (line CD in (A)), we obtain a
and inferior (I), represented by the inferobasal portion of sagittal oblique view of the heart from the left side. These
the wall (segment 4 of Cerqueira statement) that bends four walls, anterior, inferior (inferobasal), septal and
upwards in this case (B). The infarction vector generated lateral, are clearly seen in the horizontal axial plane (A),
principally in segments 4 and 10; in case of very lean and two walls, anterior and inferior including the
individuals (Figure 1.13C) it faces lead V3 and not V1 (line inferobasal segment, in sagittal-like plane (B).
CD). On the contrary, the vector of infarction that arises

(A) (B) (C)
IV: Infarction vector

Figure 1.12 (A) The posterior (inferobasal) wall as it was infarctions. The infarction vector of inferobasal and
wrongly considered to be placed. With this location an mid-segment in lean individuals faces V3–V4 and not V1,
infarction vector of inferior infarction (segments 4 and 10 and may contribute to the normal RS pattern seen in these
in case of very lean individuals) faces V1–V2 and explains leads. On the contrary, the vector of infarction of the
the RS pattern in these leads. (B, C) The real anatomic lateral wall faces V1 and may explain RS pattern in this
position of inferior wall (inferobasal) and lateral wall lead (see p. 156).



(A) (B) (C)

Figure 1.13 Sagittal-oblique view in case of not bend upward in C shape (two-third of the cases), and
normal-body-build subject (A) (G shape), in a man with only in very lean individuals with U shape, the largest part
horizontal heart (B) (C shape) and in a very lean subject of the wall is posterior (5% of the cases) (C).
(C) (U shape). We have found that the inferior wall does

The coronary tree: coronary
septal, anterior, lateral and inferior walls (Figures
angiography and coronary
1.3(1) and 1.8A; see Plate 2). Thus, the LV is di-
multidetector computed
vided into the basal area, the mid-area, the apical
tomography
(inferior) area and the strict apex area (Figures 1.8A
and 1.9).
In the past, only pathologists have studied coro-
In order to clarify the terminology of the heart
nary arteries. In clinical practice, coronary arteri-
walls, a committee appointed by ISHNE (Interna-
ography, ﬁrst performed by Sones in 1959, has been
tional Society Holter Non-invasive Electrocardiog-
the ‘gold standard’ for identifying the presence or
raphy) has made the following recommendations
absence of coronary stenosis due to IHD, and it
(Bay´ s de Luna et al., 2006c):
e
provides the most reliable anatomic information
1. Historically, the terms ‘true’ or ‘strictly posterior’
for determining the most adequate treatment. Fur-
MI have been applied when the basal part of the
thermore, it is crucial not only for diagnosis but also
LV wall that lies on the diaphragm was involved.
for performing percutaneous coronary intervention
However, although in echocardiography the term
(PCI). Very recently, new imaging techniques, espe-
posterior is still used in reference to other segments
cially CMDCT, are being used more and more with
of LV, it is the consensus of this report to abandon
a great reproducibility compared with coronary an-
the term ‘posterior’ and to recommend that the
´
giography (O’Rourke et al., 2000; Pons-Llado and
term ‘inferior’ be applied to the entire LV wall
Leta-Petracca, 2006) (Figure 1.1). CMDCT is very
that lies on the diaphragm.
useful for demonstrating bypass permeability and
2. Therefore, the four walls of the heart are named
for screening patients with risk factors. Recently, it
anterior,septal,inferior and lateral. This decision
has even suggested its utility in the triage of pa-
regarding change in terminology achieves agree-
tients at emergency departments with dubious pre-
ment with the consensus of experts in cardiac
cordial (Hoffmann, 2006). In chronic-heart-disease
imaging appointed by American Heart Associa-
patients, there are some limitations due to frequent
tion (AHA) (Cerqueira, Weissman and Disizian,
presence of calcium in the vessel walls that may
2002) and thereby provides great advantages for
interfere with the study of the lumen of the ves-
clinical practice. However, a global agreement, es-
sel. However the calcium score alone without the
pecially with an echocardiographic statement, is
visualisation of coronary arteries is important in
necessary.
patients with intermediate risk, in some series even



In the light of current knowledge, we would like to summarise the following:
right-to-left position, the vector of infarction∗ is
1. Classically it was considered that the four walls
of the heart are named septal, anterior, lateral and directed forwards, but to the left, and faces V3 and
inferoposterior. The posterior wall represents the not V1, and therefore it originates RS morphol-
part of inferoposterior wall that bends upwards. ogy in V3–V4 but not in V1. In reality the vector
2. Since mid-1960s it was defended that infarc- of infarction that explains the RS morphology in
tion of the posterior wall presents a vector of in- V1 is generated in the lateral wall (Figures 1.11
farction that faces V1–V2 and therefore explains and 1.12).
RS (R) morphology in these leads (Perloff, 1964). 4. Currently, the four walls of the heart have to
3. However, (a) infarction of the inferobasal be named septal, anterior, lateral and inferior.
segment (posterior wall) does not usually gen-
erate a Q wave because it depolarises after 40 mil-
liseconds (Durrer et al., 1970) (Figure 9.5). (b) ∗ The injury vector has approximately the same direction as
Furthermore, the CMR correlations have demon- that of the vector of ischaemia and infarction but opposite
strated that the posterior wall often does not ex- sense (see p. 35, 60 and 131 and Figures 3.6, 4.8 and 5.3).
ist, because usually the basal part of the infer- Therefore, most probably, in case of injury of the lateral
wall, an ST-segment depression will be especially recorded
oposterior wall does not bend upwards (Figure
in V1–V2, and in case of injury of the inferobasal wall,
1.13). (c) In cases that the inferoposterior wall
the ST-segment depression will be recorded especially in
bends upwards, even if the most part of inferior V2–V3. However, further perfusion studies, with imaging
wall is posterior, as may be rarely seen in very lean techniques in the acute phase have to be done to validate
individuals, as the heart is located in an oblique this hypothesis.

Most common names given along the time to the wall that lies on the diaphragm
1940s to 1950s (Goldberger, 1953) Posterior wall
Inferoposterior (basal part = true posterior)
1960s to 2000s (since Perloff, 1964)
Inferior (basal part = inferobasal)
2000s (since Cerqueira, Weissman and Disizian,
2002, and Bay´ s de Luna, 2006)
e
Therefore we consider that the four walls of the heart have to be named anterior, septal, lateral and
inferior.

The perfusion of the heart walls and
better than exercise testing, to predict the risk of
specific conduction system
IHD. CMDCT has some advantages in case of com-
plete occlusion (Figure 1.1G) and in detecting soft The myocardium and specific conduction system
plaques. It is also useful for the exact quantification (SCS) are perfused by the right coronary artery
of the lumen of occluded vessel that is compara- (RCA), the left anterior descending coronary artery
ble with intravascular ultrasound (see Figure 1.1H). (LAD) and the circumflex coronary artery (LCX).
However, it is necessary to realise the need to avoid Figure 1.1 shows the great correlation of coronary
repetitive explorations form an economical point angiography and CMDCT in normal coronary tree
of view and also to avoid possible side-effects due and some pathologic cases.
to radiation. A clear advantage of invasive coronary Figures 1.14B–D show the perfusion that the dif-
angiography is that it is possible, and this is very ferent walls with their corresponding segments re-
important especially in the acute phase, to perform ceive from the three coronary arteries. The areas
immediately a PCI. with common perfusion are coloured in grey in



(A) (B)

(E)
I

II III

(C) (D)

Figure 1.14 According to the anatomical variants of RCA or the LCX, depending on which of them is dominant
coronary circulation, there are areas of shared variable (the RCA in >80% of the cases). Segment 15 often receives
perfusion (A). The perfusion of these segments by the blood from LAD. (E) Correspondence of ECG leads with the
corresponding coronary arteries (B–D) can be seen in the bull’s-eye image. Abbreviations: LAD, left anterior
‘bull’s-eye’ images. For example, the apex (segment 17) is descending coronary artery; S1, first septal branch; D1, first
usually perfused by the LAD but sometimes by the RCA or diagonal branch; RCA, right coronary artery; PD, posterior
even the LCX. Segments 3 and 9 are shared by LAD and descending coronary artery; PL, posterolateral branch;
RCA, and also small part of mid-low lateral wall is shared LCX, left circumflex coronary artery; OM, obtuse marginal
by LAD and LCX. Segments 4, 10 and 15 depend on the branch; PB, posterobasal branch.

r Right coronary artery (RCA) (Figure 1.14C).
Figure 1.14A. Figure 1.14E shows the correlation of
ECG leads with the bull’s-eye image (Bay´ s, Fiol and
e This artery perfuses, in addition to the RV, the in-
Antman, 2006). The myocardial areas perfused by ferior portion of the septum (part of segments 3
three coronary arteries are as follows (Candell- and 9). Usually, the higher part of the septum
receives double perfusion (LAD + RCA conal
Riera et al., 2005; Gallik et al., 1995):
r Left anterior descending coronary artery (LAD) branch). Segment 14 corresponds more to the LAD,
(Figure 1.14B). It perfuses the anterior wall, espe- but it is sometimes shared by both arteries (see be-
cially via the diagonal branches (segments 1, 7 and fore). The RCA perfuses a large part of the inferior
13), the anterior part of the septum, a portion of in- wall (segment 10 and parts of 4 and 15). Segments
ferior part of the septum and usually the small part 4 and 10 can be perfused by the LCX if this artery
of the anterior wall, via the septal branches (seg- is of the dominant type (observed in 10–20% of
ments 2, 8 and part of 14, 3 and 9). Segment 14 is per- all cases), and at least part of segment 15 is per-
fused by LAD, sometimes shared with the RCA, and fused by LAD if this artery is long. Parts of the
also parts of segments 3 and 9 are shared with the lateral wall (segments 5, 11 and 16) may, on cer-
RCA. Segments 12 and 16 are sometimes perfused tain occasions, pertain to RCA perfusion if it is very
by the second and third diagonals and sometimes by dominant. Sometimes segment 4 receives double
perfusion (RCA + LCX). Lastly, the RCA perfuses
the second obtuse branch of LCX. Frequently, the
LAD perfuses the apex and part of the inferior wall, segment 17 if the LAD is very short.
r Circumflex coronary artery (LCX) (Figure
as the LAD wraps around the apex in over 80% of
cases (segment 17 and part of segment 15). 1.14D). The LCX perfuses most of the lateral



wall – the anterior basal part (segment 6) and the lateral wall) or distal branches of a non-dominant
mid and low parts of lateral wall shared with the RCA and LCX (part of the inferior wall) involves
LAD (segments 12 and 16) and the inferior part only a part of a single wall.
of the lateral wall (segments 5 and 11) sometimes In fact, whether ACSs or established infarctions
shared with RCA. It also perfuses, especially if it is involve one or more walls has a relative impor-
the dominant artery, a large part of the inferior wall, tance. What is most important is their extension,
especially segment 4, on rare occasions segment 10, related mainly to the site of the occlusion and to
and part of segment 15 and the apex (segment 17). the characteristics of the coronary artery (domi-
The double perfusion of some parts of the heart nance, etc.). Naturally, on the basis of all that was
explains that this area may be at least partially pre- previously discussed, large infarcts involve a my-
served in case of occlusion of one artery and that ocardial mass that usually corresponds to several
in case of necrosis the involvement is not complete walls, but the involvement of several walls is not al-
(no transmural necrosis). ways equivalent to a large infarct, as we have already
Both acute coronary syndromes (ACSs) and in- commented. For instance, the apex, although a part
farcts in chronic phase affect, as a result of the oc- of various walls, is equivalent to only a few segments.
clusion of the corresponding coronary artery, one Therefore knowing what segments are affected al-
part of the two zones into which the heart can be lows us to better approximate the true extension
divided (Figure 1.14A): (1) the inferolateral zone, of the ventricular involvement (Cerqueira, Weiss-
which encompasses all the inferior wall, a portion man and Disizian, 2002). Lastly, although in many
of the inferior part of the septum and most of the cases multivessel coronary disease exists, this does
lateral wall (occlusion of the RCA or the LCX); (2) not signify that a patient has suffered more than one
the anteroseptal zone, which comprises the ante- infarct.
rior wall, the anterior part of the septum and often Consequently, in order to better assess the prog-
a great part of inferior septum and part of the mid- nosis and the extent of the ACSs, and infarcts in the
lower anterior portion of lateral wall (occlusion of chronic phase, it is very important in the acute phase
the LAD). In general, the LAD, if it is large, as is to establish the correlation between the ST-segment
seen in over 80% of cases, tends to perfuse not only deviations/T changes and the site of occlusion and
the apex but also part of the inferior wall (Figures the area at risk (p. 66), and in the chronic phase
1.1 and 1.14). between leads with Q wave and number and loca-
The occlusion of a coronary artery may affect tion of left-ventricular segments infarcted (p. 139)
only one wall (anterior, septal, lateral or inferior) (Figures 1.8 and 1.9).
or, more often, more than one wall. ACSs and in- The perfusion of SCS structures is as follows:
farcts in their chronic phase, which affect only one (a) The sinus node and the sinoatrial zone by the
wall, are uncommon. Even the occlusion of the distal RCA or the LCX (approximately 50% in each case)
part of the coronary arteries usually involves several (b) The AV node perfused by the RCA in 90% of
walls. For example, the distal LAD affects the apical cases and by the LCX in 10% of cases
part of anterior wall but also the apical part, even (c) The right bundle branch and the anterior sub-
though small, of the septal, lateral and inferior wall division of the left bundle branch by the LAD
(Bogaty et al., 2002), and the distal LCX generally (d) The inferoposterior division of the left bundle
affects part of the inferior and lateral walls. In addi- branch by septal branches from the LAD and the
tion, an occlusion of the diagonal artery, although RCA, or sometimes the LCX
fundamentally affecting the anterior wall, often also (e) The left bundle branch trunk receiving double
perfusion (RCA + LAD)
involves the middle anterior part of the lateral wall
and even the occlusion of the ﬁrst septal branch This information will be useful in understanding
artery, or a subocclusion of the LAD encompassing when and why bradyarrhythmias and/or intraven-
the septal branches involves part of the septum and tricular conduction abnormalities may occur dur-
often a small part of the anterior wall. Probably, the ing an evolving ACS (see ‘Arrhythmias and intra-
occlusion of oblique marginal (OM) (part of the ventricular conduction blocks’ in ACS p. 250).

Electrocardiography In Ischaemic Heart Disease Clinical And Imagine Correlations And Prognostic

Electrocardiography In Ischaemic Heart Disease Clinical And Imagine Correlations And Prognostic

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