Idiopathic ventricular fibrillation associated with J wave and early repolarization: a really benign electrocardiographic sign?

In patients with idiopathic ventricular fibrillation, several kinds of electrocardiographic findings have been reported. Brugada electrocardiogram (ECG), a coved-type ST-segment elevation in the right precordial leads, is a well-known electrocardiographic sign, which is related to ventricular fibrillation leading to sudden cardiac death. By contrast, J wave and early repolarization are generally considered as benign manifestations on the ECG; however, they are reported as having the potential to cause cardiac arrhythmias at experimental studies. This study revealed that J wave and early repolarization were more frequent in patients with idiopathic ventricular fibrillation compared with control subjects (31 vs 5%; p < 0.0001). Moreover, a higher incidence of recurrent ventricular fibrillation was observed in patients with J wave and early repolarization on the ECG compared with those without such abnormalities (HR: 2.1; 95% CI: 1.2-3.5; p = 0.008). This study raises a question on the general concept that J wave and early repolarization are benign electrocardiographic patterns.