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ELECTROCARDIOGRAM OF THE MONTH
Electrocardiographic Recognition of Anterior Infarction in
Left Anterior Fascicular Block: A Diagnostic Challenge*
H.E . Kulbertus, M.D.Oa
ecognition of anterior infarction in the presence
of left anterior fascicular block represents a
diagnostic challenge in clinical electrocardiography.
Anterior infarction may indeed accompany or even
be responsible for left anterior fascicular block.14
On the other hand, this conduction disturbance
induces a reorientation of the initial forces of QRS
'From the Division of Cardiology, Department of Medical
Clinics and Semeiology, University of Lihge School of
Medicine, Libge, Belgium.
''Charge5 de Recherches du Fonds National de la ~kcherche
Scientifique. Maitre de Confkrences t i 1'Universitb de LiBge.
R n'nt requests: Dr. Kulbertus, Hopital de Baviere, Liege.
~3~iurn
which may by itself give rise to electrocardiographic features of anterior infarction.'
The present report illustrates two cases in which
this diagnostic problem arose and points out that
vectorcardiography appears as a method of choice
to reach the exact diagnosis.
The first electrocardiogram in Figure 1 was obtained from
a 68-year-old man with angina pectoris who presented with
an acute episode of myocardial infarction in August, 1970.
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FIGURE
1. See case reporb for
description.
H. E. KULBERTUS
FIGURE 2. Isolated QRS vectorcardiographic loops recorded using the McFee-Parungao system.
The loop is interrupted every 1/400 sec.
The tracing, recorded in April, 1971, showed sinus rhythm
with slightly prolonged P-R interval (0.20 sec). The mean
QRS axis was deviated to the left (higher than -30') and
the ventricular complexes displayed a qR morphology in
leads I and aVL and an rS morphology in leads 11, 111 and
aVF. Moreover, no initial r wave was observed in V, and V2
and a small initial q wave was seen in V3. There was no q
wave in Va. This electrocardiogram was suggestive of left
anterior fascicular block with old anteroseptal myocardial
infarction.
The second electrocardiogram in Figure 1 was recorded
prior to an operative procedure for peripheral vascular disease in a man aged 68 with previous complaints of angina
pectoris. The tracing showed sinus rhythm with normal A-V
conduction. The mean QRS axis was shifted superiorly to the
left (about -60') and the ventricular complexes showed a
qR morphology in leads I and aVL and an rS morphology in
leads 11, I11 and aVF. A normal r wave was seen in V1, but
leads V2 and V3 showed abnormal initial q waves. There was
no initial negative deflection in Va. This electrocardiogram,
which was very similar to the first one, also suggested the
diagnosis of left anterior fascicular block with old anterior
infarction.
A vectorcardiogram was recorded from both patients using
the McFee Parungao system (Fig 2). In both cases, the
frontal plane loop was open-faced and counterclockwise rotated with initial forces directed inferiorly to the right. The
efferent limb travelled horizontally to the left and the intermediate portion of the loop was markedly displaced to the
left and superiorly. Both tracings therefore met the vectorcardiographic criteria for left anterior fascicular block.5 Significant differences were nevertheless noted in the horizontal
plane. In case 1, following a tiny initial forward activity, the
centrifugal part of the loop ran a clockwise and posterior
course and the 20 msec vector was located posterior to the E
point. Those findings confirmed the diagnosis of anterior
infarction. On the other hand, in case 2, the initial forces
pointed inferiorly and slightly to the right and posteriorly. In
the horizontal plane, the QRS loop was entirely counterclockwise; its efferent portion was normal and no sign of
anterior infarction could be depicted.
Electrophysiologic studies made on isolated human hearts showed that excitation of the endocardial surface of the left ventricle simultaneously
starts at three widely separated areas6 These
islands of early depolarization are located on the
midseptal area, on the anterior paraseptal wall, and
on the posterior paraseptal wall respectively. The
initial portion of the QRS complex therefore results
from three synchronously developing wave fronts.
The endocardia1 area on the anterior basal wall
and, at least in some individuals, the midseptal area
are excited by offshoots of the anterior fasciculus of
the left bundle branch.' In the presence of left
anterior fascicular block, the electrical forces generated by the wave front originating from the
posterior paraseptal focus are left unopposed. This
phenomenon produces a reorientation of the initial
deflection of the ventricular complex which is then
directed inferiorly, slightly to the right, and sometimes p~steriorly.~.~.~
The very initial forces of the
QRS loop may thus point away from V2 and Vs and
therefore be recorded negatively in those leads.
Moreover, the direction of the initial vectors being
almost perpendicular to the horizontal plane, they
may also be poorly picked up by lead Va where the
q wave disappears. Such alterations of the initial
deflection of QRS in the precordial leads may be
misinterpreted as indicative of an old anterior
infarction. Nevertheless, careful examination of the
initial and early forces of the horizontal plane
vectorcardiogram permits the correct diagnosis.
As others, we have previously indicated that left
anterior fascicular block sometimes mimics the
electrocardiographic pattern known as 'left ventricular hypertrophy with strain.'" Case 2 of this
CHEST, VOL. 62, NO. 1, JULY, 1972
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ECG RECOGNITION OF ANTERIOR INFARCTION
report points o u t how closely this conduction disturbance may also simulate anterior myocardial
infarction. I t is suggested that a vectorcardiogram
should be recorded whenever signs of anterior
infarction a r e observed in a standard electrocardiographic tracing otherwise characteristic of left
anterior fascicular block.
REFERENCES
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1 Grant RP: Left axis deviation: an electrocardiographicpathological correlation study. Circulation 14:233, 1956
2 Davies H, Evans W: The significance of deep S waves in
leads I1 and 111. Brit Heart J 22:551, 1960
3 Bahl OP, Walsh TJ, 'Massie E: Left axis deviation. An
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electrocardiographic study with post-mortem correlation.
Brit Heart J 31:451, 1969
Rosenbaum, MB, Elizari MV, Lazzari JO: Los Hemibloqueos. Buenos Aires, Ed. Paidos, 1968
Kulbertus HE, Collignon P, Humblet L: Vectorcardiographic study of the QRS loop in patients with left anterior
focal block. Amer Heart J 79:293, 1970
Durrer D, Van Dam Th, Freud GE, et al: Total excitation
of the human heart. Circulation 41:899, 1970
Demoulin JC, Kulbertus HE: Histopathological examination of the concept of left hemiblocks ( in press )
Castellanos A, Lemberg L: Reevaluation of septal activation. Amer Heart J 78:575, 1969
Cerqueira-Comes M : Novas ideas sobre a activa~aoseptal.
0 hledico 975:492, 1970
Brief Life Span of a Genius
Franz Schubert (1797-1828) was born when Mozart
had been dead six years, and Beethoven was approaching the first crisis of his career. Popular legend used to
interpret the "bohemian" behavior of the Schubert circle as the irresponsible gaiety of the artist's life. In
fact, it grew from a deepening dispair. Schubert and
his friends were acutely conscious of the political oppression in Austria. Corruption had gone too far. One
might almost say that Schubert is a composer of Friendship. All his greatest music he wrote for himself and
his friends; yet by writing this music he was no longer
able to keep himself alive. As a freelance musician had
to produce entertainment music for a degenerate aristocracy and a sentimental bourgeoisie whose taste he
could no longer share. While he enjoyed writing his
innumerable waltzes, he would have preferred to spend
some of the time composing symphonies and sonatas.
His own quintessential music seems to be created simultaneously out of conflict with the world and out of
utopian yearning. Hence his music's combination of
strength and melancholy. He seeks his music to resolve
his frustration in love, to create a world in which ideals
are not corrupted. Communing with solitude, he discovers a world of imagination which can sooth and
satisfy as real life cannot.
Harman A, Milner A, Mellers W:
Man and His Music-The Story of
Musical Experience in the West.
New York, Oxford University Press, 1962
CHEST, VOL. 62, NO. 1, JULY, 1972
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