Drug-induced Brugada syndrome.

Survivors of sudden death without structural heart disease and a normal coronary angiogram are often diagnosed with idiopathic ventricular fibrillation (VF). The criteria for idiopathic VF have been reviewed elsewhere. However, a careful analysis of the electrocardiogram (ECG) is essential in the differential diagnosis of unexplained sudden cardiac death. We report two patients with unexplained VF, intermittent right bundle-branch block (RBBB) and ST-segment elevation in the precordial leads V1-V3. This syndrome is named after Brugada who first described a clinical series. This paper stresses the dynamic changes and the spontaneous normalization of the ECG. Class I drugs can unmask this peculiar ECG-pattern and can sometimes precipitate an arrhythmia if they are given chronically. Patients with the diagnosis of idiopathic VF should be screened for intermittent RBBB and ST-segment elevation. Because the syndrome is mostly familial and inherited as an autosomal dominant trait, diagnosis of this entity in a patient has an implication for the screening of family members.