Alcohol Septal Ablation in Obstructive Hypertrophic Cardiomyopathy: A Pilot Study

Patients with obstructive hypertrophic cardiomyopathy (HCM) and drug-refractory symptoms have traditionally been referred for cardiac surgery to widen the left ventricular (LV) outflow tract. More recently, percutaneous transluminal septal ablation (PTSA) has also been shown to thin the subvalvular septum and thereby to reduce LV outflow pressure gradients and to improve symptoms in obstructive HCM. However, this procedure is not infrequently limited by septal coronary artery anatomy and inability to identify and cannulate the appropriate artery that supplies the septal region of interest. Some attempts are also associated with coronary artery dissection, particularly, if there is associated coronary artery disease. A trans-right ventricular (RV) alcohol septal ablation (TRVASA) would significantly simplify the procedure, and increase its safety. The purpose of this study is to initially test our ability to visualize and guide a delivery catheter to a targeted part of the anterior interventricular septum involved in the generation of the LV outflow obstruction using intracardiac echocardiography (ICE). No therapy is intended: alcohol will not be injected into the septum in this initial study.