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Chronic Idiopathic Idioventricular Tachycardia Caused by Slow Response Automaticity
Author(s) -
CHIALE PABLO A.,
SICOURI SERGE J.,
ELIZARI MARCELO V.,
ROSENBAUM MAURICIO B.
Publication year - 1987
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.1540-8159.1987.tb04972.x
Subject(s) - medicine , disopyramide , cardiology , verapamil , digoxin , asymptomatic , amiodarone , tachycardia , sinus rhythm , electrocardiography , anesthesia , atrial fibrillation , heart failure , calcium
A 22‐year‐old female, asymptomatic and without any evidence of cardiac disease, was found to have a persistent idioventricular tachycardia (IVT). Sinus rhythm and IVT rates were similar and showed parallel changes in successive resting electrocardiograms. Both IVT and sinus rhythm were transiently slowed or suppressed by vagal stimulation and accelerated by sympathetic stimulation. Long periods of atrial overdrive pacing, at a rate 62% faster than the spontaneous rate of IVT, depressed both ectopic and sinus activity. Fast channel blocking agents (lidocaine, disopyramide), and digoxin and amiodarone failed to modify IVT significantly. Verapamil, a calcium channel blocking drug, allowed total control of the arrhythmia. These electrophysiologic and pharmacologic responses suggest that the IVT may relate to the automatic activity of a ventricular focus of the “slow response” type, functionally resembling an “additional” sinus node with preserved innervation. During an 88‐month follow‐up, the patient continued to be asymptomatic, warning arrhythmias were never found and the features of IVT remained unmodified.