The effect of ventricular arrhythmias (VA) on survival was retrospectively reviewed in 41 patients (33 men, 8 women) who were supported with Thoratec ventricular assist devices (VAD [Thoratec Medical Inc., Berkeley, CA]) (17 left, 9 right, and 15 biventricular). Ages ranged from 15 to 71 years (mean, 56 years), and duration of support was 0.1-17 days (mean, 4.7 days). There was no significant difference in age, gender, or type of support between survivors and nonsurvivors, and no correlation between the type of support and incidence of VA. Only two patients (both on left ventricular assist devices [LVAD]) died as a direct result of VA. There was no significant difference in the occurrence of VA before or during VAD support between survivors and nonsurvivors. These data show that evidence of VA is not a predictor of survival in patients in whom myocardial recovery is expected.