The first are patients with a clear diagnosis of hypertrophic cardiomyopathy, with significant symptoms and unsuccessful or unsatisfactory drug therapy; significant obstruction of the left ventricular outflow tract due to the anterior mitral valve leaflet and thickened left ventricular outflow tract myocardium with a differential pressure of more than 50 mm Hg; septal thickness of more than 15 mm; age of more than 21 years old; and patients who are not able to undergo surgical procedures or who very much refuse to have surgical procedures done. The incidence of third-degree atrioventricular block after alcohol ablation therapy is high, with 50% of patients experiencing a transient block and an additional 10%-20% requiring a permanent pacemaker.