during 55 antiarrhythmic drug trials ( 24 of procainamide , 21 of quinidine , 10 of disopyramide ) in the 24 patients , 6 patients had a proarrhythmic response : sustained monomorphic ventricular tachycardia in 3 , ventricular fibrillation in 2 , nonsustained monomorphic ventricular tachycardia in 1 .
C0003195
antiarrhythmic
C0034414
quinidine