A case of idiopathic ventricular fibrillation with incomplete right bundle branch block and persistent ST segment elevation.

We report the case of a 42-year-old male who suffered from ventricular fibrillation (VF) without obvious QT prolongation. His electrocardiogram showed incomplete right bundle branch block (IRBBB) and persistent ST segment elevation in the right precordial leads during sinus rhythm. Cardiac catheterization revealed no overt heart disease except moderate endocardial and subendocardial fibrosis in the left ventricle. Mental stress seemed to trigger VF, and ST elevation became prominent just before VF. Propranolol and mexiletine have been effective in preventing VF for over 3 years.