Proarrhythmic ECG deterioration caused by myocardial ischemia of the conus branch artery in patients with a Brugada ECG pattern.

The Brugada-type electrocardiogram (ECG) is characterized by ST-segment elevation in the right precordial ECG leads and has been reported to have the potential of sudden death. Right ventricular outflow tract supplied from the conus branch of the coronary artery (CB) is considered as the anatomopathologic substrate of Brugada syndrome. We experienced two asymptomatic patients with a saddleback Brugada-type ECG who exhibited a dynamic ECG conversion to a coved type following a ventricular fibrillation/ventricular tachycardia (VT/VF) episode when myocardial ischemia occurred exclusively at the CB. Some types of Brugada syndrome might be caused VT/VF by selective myocardial ischemia at the CB.