Septal Reduction Using Transvenous Intramyocardial Cerclage Radiofrequency Ablation: Preclinical Feasibility

•Surgical myectomy is morbid and transcoronary alcohol septal ablation can result in geographic miss or occasional nontarget injury.•We developed a transvenous intraseptal radiofrequency ablation technique (cerclage ablation method) to overcome the shortcomings of surgical myectomy and alcohol septal ablation.•We delivered dedicated intraseptal radiofrequency ablation catheter into the ventricular septum through the coronary sinus and a septal vein. The ablated volume of myocardium was larger at higher electrode temperatures and using an irrigated-ablation mode in vitro. Cerclage ablation was successful in all in vivo attempts and induced a focal regional wall motion abnormality at later follow-up.•This study presents in vivo evidence of the feasibility, effectiveness, and safety of cerclage ablation method to debulk interventricular septal myocardium.