Predictors of ventricular tachycardia recurrence in 100 patients receiving tiered therapy defibrillators

Background and hypothesis: Programmed electrical stimulation (PES) is a time-honored diagnostic tool in patients with ventricular tachyarrhythmias. The response to PES can be used to assess efficacy of pharmacologic or electrical therapy, as well as to obtain prognostic information. Reproducible induction of ventricular tachycardia with invasive electrophysiologic testing, or stimulation through defibrillator lead systems, can help optimize antiarrhythmic drug therapy and device programming during clinical follow-up. Methods: We present our experience with 100 patients who had inducible sustained monomorphic ventricular tachycardia (SMVT) during invasive PES at baseline, and received a third-generation implantable cardioverter-defibrillator (ICD) alone, or in combination with antiarrhythmic drug therapy. Noninvasive programmed stimulation (NIPS) was performed prior to hospital discharge in 61 patients. Results: The inducibility of SMVT was concordant between the invasive study and NIPS in a subgroup of 40 (82%) patients who had invasive PES on the same drug regimen. During a mean follow-up of 16 months, there were 12 nonarrhythmic deaths and recurrence of spontaneous SMVT in 36 (40%) of the surviving patients. Using a Cox proportional hazards model, the following variables were associated with early arrhythmia recurrence: persistent inducibility of SMVT during the NIPS session (relative risk 11, range 2.6-47); induction of SMVT with a cycle length > 280 ms during invasive baseline PES (2.5, 1.2-5) and presence of prior inferior myocardial infarction (2.1, 1-4.2). Timing to initial recurrence of spontaneous tachycardia was unaffected by other clinical variables or concomitant antiarrhythmic drug use. Conclusion: Programmed electrical stimulation techniques offer insight into the patterns of spontaneous ventricular tachycardia recurrence and have significant practical utility in the management of patients receiving third-generation ICDs.