Quinidine induced electrocardiographic normalization in two patients with Brugada syndrome

Two patients with Brugada syndrome are presented. The ECGs showed right pre cordial J waves and ST-segment elevation. Patient 1 was resuscitated from n octurnal ventricular fibrillation, patient 2 was asymptomatic. In only pati ent 1, flecainide was infused causing monomorphic "malignant" ventricular e xtrasystoles (R on T), demonstrating the deleterious effect of Class IC ant iarrhythmic drugs in Brugada syndrome. However, administration of the Class la antiarrhythmic drug quinidine caused normalization of the ECG in both p atients. Based on in vitro experiments, agents that reduce the magnitude of I-to-mediated phase 1 have been suggested to normalize ST-segment elevatio n in Brugada syndrome. This is the first clinical report of such a quinidin e induced ECG normalization.