Introduction
Hypertrophic cardiomyopathy (HCM) is a heterogeneous monogenic heart disease characterized by a small left ventricular cavity and marked hypertrophy of the myocardium, with a prevalence of 0.2 to 0.5 % around the world. Obstruction of the left ventricular outflow tract (LVOT) is a major hallmark of HCM, present in approximately two-thirds of patients, classified as hypertrophic obstructive cardiomyopathy (HOCM). Reduction of LVOT gradients has been shown to improve symptoms and possibly prognosis.1-3 For patients with severe and highly symptomatic LVOT obstruction despite medication, transaortic surgical myomectomy has been considered the gold standard for many years. Alcohol septal ablation (ASA) has been utilized recently as a minimally invasive alternative to surgical myectomy.4-6 Experience with permanent pacemaker (PPM) implantation to force RV pacing and RV/LV dys-synchrony as another treatment has fallen out of favor.7, 8
Recently, endocardial catheter-based septal radiofrequency ablation of the LVOT has been utilized to treat HOCM. Catheter ablation, particularly with utilization of an electroanatomic mapping system and/or intracardiac echocardiography (ICE), may allow a higher degree of ablative accuracy, resulting in potentially more effective relief of obstruction and less risk of collateral myocardial and other injury. Single-center evidence has demonstrated that endocardial radiofrequency ablation for septal hypertrophy might be an option for patients with HOCM in order to alleviate the LVOT gradient.9-14 The accuracy of tissue damage and improvement in LVOT gradient, symptoms, and quality of life in this preliminary group of patients appears promising.9 However, to date, the selection of appropriate patients for this procedure remains unclear. In this study, we collected data from patients who underwent septal ablation and assessed the factors that may influence treatment outcomes.