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.