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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. 2 - . -+ I Downloaded From: http://publications.chestnet.org/pdfaccess.ashx?url=/data/journals/chest/21541/ on 05/02/2017 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 Downloaded From: http://publications.chestnet.org/pdfaccess.ashx?url=/data/journals/chest/21541/ on 05/02/2017 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 4 5 6 7 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 8 9 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 Downloaded From: http://publications.chestnet.org/pdfaccess.ashx?url=/data/journals/chest/21541/ on 05/02/2017