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Spontaneous Termination of Reentry Ventricular Tachycardia in the Late Myocardial Infarction Period: An Experimental Study in the Dog
Author(s) -
OGAWA SATOSHI,
KAPLINSKY ELIESER,
DREIFUS LEONARD S.
Publication year - 1979
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/j.1540-8159.1979.tb03646.x
Subject(s) - medicine , endocardium , efferent , cardiology , reentry , ventricular tachycardia , myocardial infarction , tachycardia , border zone , ventricular fibrillation , infarction , afferent
Forty episodes of induced ventricular tachycardia in the late myocardial infarction period (4‐6 days old) were analyzed in 12 dogs in an attempt to identify the possible mechanisms for the termination of reentry tachycardia. Multiple epicardial and endocardial composite electrograms were recorded in and around the central ischemic zone of the infarction. During tachycardia, the earliest site of activation was identified in the epicardial surface of the border or normal zone immediately adjacent to the ischemic zone in 36 of the 40 episodes, suggesting efferent epicardial spread from the site of the activity. In four instances, the efferent pathways were directed to the endocardial surface Four distinct patterns of activation sequences were observed during spontaneous termination: (a) a shift of the efferent pathways from epicardial to endocardial site (19 instances); (b) a change of the efferent pathways within the endocardium (4 instances); (c) a shift of the earliest site of activation between the left arid right ventricles (9 instances); and (d) no apparent change in the epicardial efferent pathways (4 instances). In four other instances, ventricular tachycardia deteriorated into ventricular fibrillation. In patterns (a) and (c), a shift of the efferent pathways resulted in a more rapid and homogeneous activation of the border and normal zone epicardium. These changes were associated with cessation of delayed or continuous activity in the ischemic zone epicardium, resulting in termination of tachycardia. (PACE, Vol. 2, May‐June, 1979)