DISCREPANT DRUG-ACTION OF DISOPYRAMIDE ON ECG ABNORMALITIES AND INDUCTION OF VENTRICULAR ARRHYTHMIAS IN A PATIENT WITH BRUGADA-SYNDROME

An electrophysiologic study was attempted in a patient who experienced cardiac arrest. Programmed electrical stimulation from the right vent ricle, without the use of any drugs, induced ventricular fibrillation (VF) twice. Disopyramide prevented the induction of ventricular arrhyt hmia by rendering VF to a nonsustained polymorphic ventricular tachyca rdia when administered at 300 mg/day, and noninducible at 400 mg/day. However, ST segment elevation and the rSr' pattern in leads V1-3 chara cteristic of Brugada syndrome became exaggerated by disopyramide. Diso pyramide exerted discrepant action on the electrocardiographic (ECG) a bnormalities and induction of VF in this patient, suggesting the effic acy of antiarrhythmic drugs assessed by an electrophysiologic study ma y be unrelated to ECG abnormalities in cases of Brugada syndrome.