Matching approved "nondedicated" hardware to obtain biventricular pacing and defibrillation: Feasibility and troubleshooting

Biventriculor IGDs may offer increased benefit for patients with severe congestive heart failure and ventricular arrhythmia. Currently there are no approved dedicated biventricular ICDs available. Twenty-one consecutive patients who had approved nondedicated hardware implanted for biventricular Pacing and defibrillation wore included in this study. All device therapies were evaluated using stored electrograms. During mean follow-up at 13 +/- 7 months, 8 (36%) patients had inappropriate shocks. Ventricular fibrillation therapy was delivered for slow ventricular tachcardia because of double counting in two patients. In one patient, AV nodal reentrant tachycardia below detection rate cut off triggered device therapy because of ventricular double. counting. Sinus tachycardia or premature atrial contraction initiating AV conduction and ventricular double counting resulted in shocks in five patients. The number of shocks per patient ranged from 1 to 64, Two patients required transient disconnection of the LV lead and subsequent ICD generator replacement for premature battery depletion. Two patients required AV junction ablation and three needed slow pathway ablation. Two patients were treated by upgrading to a device that was capable of a higher atrial trucking rate. The patients with impaired AV conduction or constant ventricular pacing did not have inappropriate therapy for sinus tachycardia or supraventricular arrhythmia. Use of conventional nondedicated hardware for biventricular pacer/defibrillator is feasible but should be considered only in patients with poor A 17 node function or less likely to require antitachycardic therapy, to avoid ICD double counting of ventricular sensed events and consequent high incidence of inappropriate therapies.