Alcohol septal ablation is a minimally invasive treatment for hypertrophic cardiomyopathy (HCM), an inherited disease in which parts of the heart muscle become abnormally thick, making it harder for the heart to pump blood through the body. In this procedure, alcohol is injected into the thickened area, causing some of the cells to shrink and die. Thinning the tissue allows blood to move through the heart more freely, alleviating many HCM symptoms.