To evaluate the effect of amiodarone on implantable cardioverter defibrillator efficacy, we compared first shock conversion rates for ventricular fibrillation in 113 patients who received amiodarone to those in 641 patients who did not receive the drug. All patients received a CPI VENTAK P2 implantable cardioverter defibrillator. The first shock conversion rate for spontaneous ventricular fibrillation was lower for patients taking amiodarone (62 por cento vs 88 por cento. p < 0.01). Multivariate anysis selected amiodarone use (odds ratio 5.3) and lower first shock energy (odds ratio 0.9) as predictors of first shock failure.

Conclusions:

amiodarone use was associated with decreased implantable cardioverter defibrillator shock efficacy.