Ischemia-induced Brugada-type ST-segment alternans and Brugada syndrome.

Abstract The mechanisms of Brugada-type electrocardiographic (ECG) pattern remain unclear. Methods The ST-segment was evaluated during coronary intervention of proximal right coronary artery (RCA). We measured ST-segment elevation with a drug challenge test with a sodium channel blocker. The ST-segment changes were compared with those in true Brugada syndrome. Results Brugada-type ECG was observed in 6 patients but not in 9 patients during coronary intervention. Five patients demonstrated Brugada-type ST elevation and alternans from coved type to saddleback type during coronary intervention. The patients with ST alternans demonstrated the conus branch occlusion or RV branch occlusion. A drug challenge test developed a significant ST-segment elevation neither in patients with Brugada-type ECG nor in patients without Brugada-type ECG. (0.69±0.48 mv vs. 0.48±0.31 mv, p =NS) There was a significant difference in the ST-segment elevation between patients with Brugada-type ECG during the coronary intervention and patients with true Brugada syndrome ( n =5). (0.69±0.48 mv vs. 2.86±0.61 mv, p Conclusions Ischemia of proximal RCA can masquerade as the Brugada syndrome, ST-segment elevation and alternans. Ischemia of proximal RCA could be one of the different entities showing Brugada-type ECG from true Brugada syndrome.