Catheter ablation of idiopathic ventricular tachycardia.

Idiopathic ventricular arrhythmias can originate from either the endocardial, midmyocardial, or epicardial regions of the heart. The outflow tracts and basal regions of the ventricle tend to be common locations of origin of these tachycardias. The anatomy of this region of the heart is both fascinating and, at times, challenging from a procedural standpoint. The orientation of the outflow tracts and basal regions allows mapping of ventricular tachycardias (VTs) using multiple anatomic approaches, such as through the coronary vasculature, directly through a percutaneous pericardial approach (transverse sinus), and through the atrial appendages.1 The intricate relationship of the outflow and basal regions of the ventricles to the coronary vasculature (arteries and veins) provides useful avenues for epicardial mapping and catheter ablation (Figure). Coronary veins provide endovascular access to the epicardial regions of the ventricles, especially the crucial area between the junction of the great cardiac vein and the anterior interventricular vein (Figure).