Thirty-eight patients with a prior history of cardiac arrest underwent programmed electrical stimulation (PES) studies and serial drug testing. Lorcainide was tested acutely in all 38 patients and prevented ventricular tachycardia (VT) or ventricular fibrillation (VF) induction in 14 patients and failed in 24 (efficacy rate 37%). Procainamide had failed clinically (cardiac arrest or breakthrough VT) in 16 patients, seven patients had previously severe adverse side effects, and thus only 15 were tested on procainamide at PES testing with seven protected. Following initial studies, 14 patients were started on lorcainide oral therapy and 24 on other therapy determined effective at PES testing (N-acetylprocainamide-two, flecainide-nine, bethanidine-three, slow-release procainamide hydrochloride-three, quinidine-two, cibenzoline-one, amiodarone-four). After 29 ± 7 months follow-up, three are alive on lorcainide therapy, five discontinued therapy due to side effects; six died—three sudden deaths (33%) and two cardiac deaths (both myocardial infarctions). Twenty out of 24 patients are alive who were started on PES predicted effective therapy other than lorcainide; four died—three sudden deaths (13%) and one cardiac nonsudden death. Antiarrhythmic therapy guided by PES studies gives overall encouraging results in a cardiac arrest group of patients. Lorcainide, however, is not tolerated well and affords less protection against a sudden death recurrence than is noted in a population on other antiarrhythmic therapy predicted effective at PES testing.