Intraoperative Mapping is Not Necessary for VT Surgery

Surgical ablation of ventricular tachycardia is generally guided by the results of pre‐ and intraoperative cardiac mapping. However, in certain situations intraoperative cardiac mapping may not be possible and, therefore, surgery has to be based on information obtained preoperatively. This raises the question whether intraoperative mapping is necessary for the success of this approach. We describe our experience with encircling endocar‐dial cryoablation for ischemic VT and examine the contribution of intraoperative mapping for this procedure. Thirty‐three patients with inducibie VT refractory to medical therapy and a well defined anatomic scar were considered for surgery. All patients underwent baseline electrophysiology study and intraoperative mapping was attempted during normothermic cardiopulmonary bypass. In 14 patients, VT was inducibie intraoperatively (Group 1) and surgical ablation was guided by this information, whereasin 19patients, VT could not be mapped for various reasons (Group 2). Reasons for failure to obtain intraoperative map included noninducibility (3), nonsustained VT (8), polymorphic VT (4), VF (3), and incessant VT with hemodynamic collapse and cardiac arrest (1). The two groups did not differ with respect to age, location of myocardial infarction, or preoperative left ventricular ejection fraction. The operative procedures were similarin the twogroups with respect to aortic cross clamp time, cardiopulmonary bypass time, number of cryoablation lesions, concomitant revascularization, aneurysmectomy, and ICD implantation. Encircling endocardial cryoablation was performed in 32 patients and one patient underwent partial right ventricular free wall disconnection (RV infarct). Thirteen patients underwent concomitant coronary artery bypass grafting (5 in Group 1 and 8 in group 2). One patient had prophylactic ICD patches (Group 1). The mean LVEF pre‐ and postoperatively were similar in the two groups. One patient died postoperatively. Three patients had recurrent VT perioperatively: one patient was treated with amiodarone and two had an ICD implantation. During long‐term follow‐up (mean 5 years), survival was similar in the two groups. Conclusions: Encircling endocardial cryoablation for ventricular tachycardia is a useful surgical technique in selected patients. Preoperative cardiac mapping is useful in defining a surgical plan, but intraoperative mapping is not crucial to the success of encircling endocardial cryoablation.