Hypertrophic cardiomyopathy is a cardiomyopathy characterized by hypertrophy of the left or right ventricle (often asymmetric hypertrophy with septal involvement), impaired left ventricular blood filling, and decreased diastolic compliance. If it is accompanied by left ventricular outflow tract obstruction, it is called hypertrophic obstructive cardiomyopathy. Clinical symptoms include shortness of breath and chest pain during physical activity, dizziness or fainting, panic or embolism of the body circulation due to atrial fibrillation in about 10% of cases, and congestive heart failure, telangiectatic breathing and acute pulmonary edema in advanced cases. Electrocardiography, echocardiography and cardiac catheterization help to determine the diagnosis. As a noninvasive test, echocardiography is of great significance in the diagnosis of hypertrophic obstructive cardiomyopathy. It is characterized by a ratio of the septum to the thickness of the posterior left ventricular wall ≥1.3 during diastole, protrusion of the septal outflow tract partially into the left ventricular cavity, and anterior mitral valve leaflets moving forward during systole. Using color Doppler, the pressure difference before and after the obstruction can be calculated. The treatment of hypertrophic obstructive cardiomyopathy includes pharmacological treatment, surgical treatment and percutaneous septal chemical ablation. Pharmacological treatment mainly includes betablockers (e.g., betaxolol, bisoprolol) and non-dihydropyridine calcium antagonists (e.g., isopodine, heparin). 2. Surgical septal myocardial resection. It requires open-heart surgery and extracorporeal circulation, but it is more traumatic and not many medical institutions in China carry out septal myocardial resection. 3.Percutaneous septal chemical ablation. If the clinical symptoms are obvious, the effect of medical treatment is not satisfactory, and the systolic pressure difference between the left ventricular cavity and the outflow tract at rest exceeds 6.6 kPa (50 mmHg), percutaneous septal chemical ablation can be considered. This is a minimally invasive procedure. The main steps are: first, puncture the radial artery at the wrist or the femoral artery at the root of the thigh, then place a special catheter through the artery at the opening of the left coronary artery to establish access; second, place a hair-thin soft wire through the catheter to the first septal branch of the left coronary artery; third, follow a balloon catheter to the first septal branch and withdraw the wire; fourth, dilate the balloon. The fourth step is to dilate the balloon and inject contrast agent into the distal part of the first septal branch through the central lumen of the balloon catheter to understand the extent of blood supply of this vessel, and to observe whether and to what extent the left ventricular outflow tract obstruction is reduced after the first septal branch is blocked; during echocardiography, sonovir is injected into the distal part of the first septal branch to further understand the specific part of the septum supplied by this vessel, and the blood supply of this vessel to the papillary muscle should be excluded; the fifth step is to clarify the patient After suitable chemical ablation, 1-2 ml of anhydrous alcohol is slowly injected into the distal segment of the first septal branch through the central lumen of the balloon, and a reduction or even disappearance of the pressure step difference in the left ventricular outflow tract can be observed immediately. Of course, the procedure also requires close electrocardiographic and blood pressure monitoring and the placement of a temporary pacemaker to prevent conditions such as bradycardia. Percutaneous septal chemical ablation is less invasive, easier to perform, and more effective, making it more acceptable to patients. It is estimated that 15-20 times more patients are currently undergoing percutaneous septal chemical ablation than surgical septal myocardial resection. However, percutaneous septal chemical ablation is, after all, a destructive procedure, which artificially results in controlled partial septal myocardial necrosis, so the complications of the procedure are higher than those of other coronary interventions.