Left ventricular tachycardia originating near the left main coronary artery.

Eight patients with idiopathic ventricular tachycardia (VT) underwent mapping and radiofrequency ablation. Mapping showed VT originating in the high posterolateral left ventricular outflow tract in proximity to the left main and proximal circumflex coronary arteries. Ablation was not attempted due to this proximity to the left main and proximal circumflex coronary arteries. Ablation was not attempted due to this proximity in 2 patients and limited in 1 patient. It was successful in VT suppression in 5 of 6 patients.