Catheter Ablation of Idiopathic Ventricular Tachycardia Arising from the Aortic Root

Most idiopathic ventricular tachycardia (VT) arises from the area of the outflow tracts, and the most common left ventricular site is the aortic root, usually from the right and left sinuses of Valsalva. This site of origin is suggested by specific patterns on the electrocardiogram. Activation mapping and pace mapping are both useful strategies, and their relative benefits and limitations need to be appreciated. The mapping strategy for a VT of suspected aortic root origin is based on the consideration that multiple chambers may need to be mapped, and the temptation to ablate at suboptimal sites based on the justification that it was easy to get to should be resisted. The entire surface of each cusp needs to be sampled, as distinct activation times and pacemaps are obtained at each site. Standard radiofrequency energy is typically adequate and the precision of mapping rather than the amount of tissue ablated is tantamount to success. In my opinion, the indications for ablation of aortic root VT are similar to those for other idiopathic VT. Although I offer patients both pharmacologic and nonpharmacologic options, I feel that ablation is first line therapy for patients with sufficient symptoms to warrant therapy.