Unmasking of J waves during right coronary angiography in patients with spontaneous coronary spasms and ventricular fibrillation.

We encountered two consecutive cases with spontaneous ST elevation due to right coronary spasms and subsequent ventricular fibrillation (VF). Their 12-lead ECGs on anterior chest pain showed elevation of ST-segments in the inferior leads, but coronary angiography (CAG) revealed no significant stenosis. Both cases showed dramatically evolving J waves in the inferior leads during the right CAG, but it was not observed during angiography of the left CAG. Neither Brugada-type ECG nor long-QT was evident. In summary, J waves can be produced without ST-segment elevation, and contrast media-induced J waves might be related to the arrhythmogenesis of subsequent VF evoked by right coronary spasms.