Abstract 14364: Atrial Fibrillation With Rapid Ventricular Response Induced Ventricular Tachycardia Terminated by Intrinsic Anti-Tachycardia Pacing - A First in Literature Case Report

Abstract

Background: Intrinsic anti-tachycardia pacing (iATP) is a novel tailored algorithm that has shown increased efficacy against ventricular tachycardia (VT), including fast VT. We describe a case of atrial fibrillation (AF) with rapid ventricular response (RVR) induced VT terminated by iATP. Case description: A 71-year-old male with coronary artery disease, heart failure (EF 30-35%), atrial fibrillation, VT status post biventricular implantable cardioverter defibrillator and failed renal transplant presented with syncope during dialysis. His home medications included amiodarone, metoprolol, apixaban. He was hemodynamically stable on presentation. He had bilateral pitting edema with a systolic murmur and bilateral basilar crackles on exam. His labs were consistent with anemia and end stage renal disease. His device interrogation (Figure) showed AFRVR which degenerated to VT with final cycle length (CL) of 290 msec. First round of ATP with S1x10 burst pulses (88%, CL 250msec) and S2 extra stimuli (CL 230 msec) failed to terminate the VT. Post pacing interval (PPI) was 450 msec. Given calculated remote distance, another five rounds of adaptive iATP with similar S1 pulses but faster S2 and addition of S3 extra stimuli were delivered but were unsuccessful in terminating VT. Finally, the seventh round of iATP (S1x10 at CL 260 msec, S2 at 240 msec) was successful at conversion to sinus rhythm briefly before reverting to AF with controlled ventricular pacing. Discussion: ATP decreases ICD shocks but is programmed empirically and there is less success with fast VT. iATP analyses the PPI of the prior failed sequence to adjust the subsequent ATP therapy by altering the number of burst pulses (S1) and addition of ramp extra stimuli. Computational models and early clinical experience have shown increased efficacy of iATP in terminating fast VT without concomitant increase in VT acceleration. To the best of our knowledge, this is first case report of AFRVR induced VT terminated by iATP.