Recurrent Ventricular Tachycardia Induced by an Atrial Synchronous Ventricular-Inhibited Pacemaker

Atrial synchronous pacemakers have been known to cause a variety of cardiac arrhythmias. Of particular concern are those arrhythmias invoiv ing a pacemaker stimuius occurring on a T wave, because these may lead to ventricuiar tachycardia. The Medtronic 2409 ASVIP pacemaker is an atrial synchronous pacemaker with several features de signed to decrease the likelihood of such arrhythmias. We report a patient in whom a normally func tioning Medtronic 2409 ASVIP pacemaker, despite these features, induced recurrent ventricular tachycardia. Conditions which predisposed this patient to pacemaker-induced re-entrant arrhythmias are discussed. [PACE, Vol. 5, July-August, 1982]