In a patient referred for the evaluation of non-sustained monomorphic ventricular tachycardia on Holter recordings, ventricular fibrillation was electrically induced during electrophysiologic study. Despite the absence of structural heart diseases, his ECG revealed J wave and ST segment elevation in the inferior leads, which showed circadian variation and were augmented by the sodium channel blocker, pilsicainide. This case might lead us to notice a new concept, a 'latent' type of variant Brugada syndrome, and these ECG findings and changes might serve as its diagnostic sign.