Radiofrequency catheter ablation of ventricular tachycardia from the anterobasal left ventricle.

Ventricular tachycardia (VT) in coronary artery disease arises mostly from endocardial sites. However, little is known about the site of origin in other diseases. We report two patients who had VT originating from an anterior aspect of the left ventricle just below the mitral annulus, adjacent to the left ventricular outflow tract. The QRS configuration of VT showed an inferior axis and monophasic R waves in all the precordial leads. Radiofrequency current delivered to this site from the endocardial site successfully ablated the tachycardia in both.