Electrophysiologic characteristics and catheter ablation of ventricular tachyarrhythmias among patients with heart failure on ventricular assist device support.

Background: Ventricular tachyarrhythmias (VT) are common among ventricular assist device (VAD) recipients, yet electrophysiologic (EP) characteristics and catheter ablation outcomes remain uncharacterized.

Objective: To evaluate the EP characteristics and catheter ablation outcomes for VTs among heart failure patients on VAD support.

Methods: The Cleveland Clinic registry of consecutive patients undergoing VAD placement in 1991-2010 with medically refractory, symptomatic VT referred for EP study and catheter ablation.

Results: Among 611 recipients of VAD (mean age 53.3 ± 12.4 years, 80% men), 21 patients (3.4%) were referred for 32 EP procedures, including 11 patients (52%) presenting with implantable cardioverter-defibrillator therapy (13 shocks, 26 antitachycardia pacing). Data from 44 inducible tachycardias (mean cycle length 339 ± 59 ms) demonstrated monomorphic VT (n = 40, 91%; superior axis 52%, right bundle branch block morphology 41%) and polymorphic ventricular tachycardia (PMVT)/ventricular fibrillation (n = 4, 8%). Electroanatomic mapping of 28 tachycardias in 20 patients demonstrated reentrant VT related to intrinsic scar (n = 21 of 28, 75%) more commonly than the apical inflow cannulation site (n = 4 of 28, 14%), focal/microreentry VT (n = 2 of 28, 7%), or bundle branch reentry (n = 1 of 28, 3.5%). Catheter ablation succeeded in 18 of 21 patients (86%). VT recurred in 7 of 21 patients (33%) at a mean of 133 ± 98 days, and 6 patients (29%) required repeat procedures, with subsequent recurrence in 4 of 21 patients (19%).

Conclusions: Catheter ablation of VT is effective among recipients of VAD. Intrinsic myocardial scar, rather than the apical device cannulation site, appears to be the dominant substrate.