PREDICTORS OF DEVICE ACTIVATION FOR VENTRICULAR ARRHYTHMIAS AND SURVIVAL IN PATIENTS WITH IMPLANTABLE PACEMAKERS DEFIBRILLATORS/

Predictors of survival and arrhythmia recurrence for patients with imp lanted defibrillators have been reported but patients with sustained, well-tolerated ventricular tachycardia were often excluded from these trials. Arrhythmia recurrence and survival in populations including th ese patients have been less well studied. The purpose of the present s tudy was to examine predictors of spontaneous ventricular arrhythmias and mortality in patients who received a tiered therapy antitachycardi a pacemaker/defibrillator for ventricular tachycardia, fibrillation, o r both. Three hundred thirty-seven patients who received a Ventritex C adence(R) tiered therapy antitachycardia, device at one of 19 particip ating centers between July 11, 1989 and March 4, 1991 are included in this retrospective analysis. Diagnostic summary data and stored electr ograms telemetered from the implanted device were assessed to determin e characteristics of recurrent arrhythmias. Mean follow-up was 360 +/- 10 (SEM) days. Thirty-three patients died during follow-up. At least one recurrent ventricular arrhythmia was observed in 205 patients (61% ). A total of 7,539 episodes were observed with a mean of 37 +/- 5 per patient. Patients with recurrent ventricular arrhythmias were slightl y but significantly older (64 +/- 0.7 vs 59 +/- 1.2 years; P < 0.001) but were not distinguished by gender or underlying structural disease. Patients whose presenting arrhythmia was monomorphic ventricular tach ycardia were more likely to experience recurrent ventricular arrhythmi as (69% recurrence rate) than patients presenting with ventricular fib rillation or polymorphic ventricular tachycardia (46% recurrence rate; P < 0.001). Cycle length of spontaneous tachycardia was also a predic tor of arrhythmia recurrence. Patients having slower ventricular arrhy thmias were less likely to remain recurrence free. Mean left ventricul ar ejection fraction was similar for patients with and without recurre nces. Younger age and absence of arrhythmia recurrence but not present ing arrhythmia were predictors of survival. We conclude that age and p resentation with monomorphic ventricular tachycardia are important pre dictors of arrhythmia recurrence for this patient population. Exclusio n of patients with monomorphic ventricular tachycardia underestimates the rate of recurrent ventricular arrhythmias and utilization of devic e therapy.