Indications for internal cardioverter defibrillator implantation predict time to first shock and the modulating effect of β-blockers

Time to first shock is determined by the indication for ICD implantation and is not predicted by the results of EPS. Patients with secondary indications for ICD implantation are at highest risk of shocks and may deserve consideration for prophylactic antiarrhythmic drugs. β-Blockers increase the time to first ICD shock in patients implanted for secondary prevention of sudden death.