Hypertrophic obstructive cardiomyopathy is characterized by hypertrophy of the ventricular myocardium, typically in the left ventricle, especially in the septum, and occasionally as concentric hypertrophy. The left ventricular chamber volume is normal or reduced. Occasionally, the lesion occurs in the right ventricle. It is usually inherited in an autosomal dominant fashion. Symptoms 1. Dyspnea: It occurs mostly after exertion and is due to reduced left ventricular compliance, increased end-diastolic pressure, followed by increased pulmonary venous pressure and pulmonary stasis. Mitral valve insufficiency with septal hypertrophy can aggravate pulmonary stasis. 2, precordial pain: mostly after exertion, like angina pectoris, but atypical, due to increased oxygen demand of hypertrophied myocardium and relative lack of coronary artery blood supply. 3, weakness, dizziness and fainting: mostly occur during activity, because the heart rate is accelerated, which further shortens the diastolic period of the left ventricle, which is already poorly filled in the diastolic period, aggravating the underfilling and reducing the cardiac blood output. During activity or emotional excitement, the sympathetic nerve strengthens the contraction of the hypertrophied myocardium, aggravating the outflow tract obstruction and causing a sudden decrease in cardiac blood output. 4, palpitations: due to cardiac hypoperfusion or arrhythmia. 5.Heart failure: mostly seen in advanced patients, due to reduced myocardial compliance, significant increase in ventricular end-diastolic pressure, followed by increased atrial pressure, and often combined with atrial fibrillation. In advanced patients, myocardial fibrosis is widespread and ventricular systolic function is also reduced, making them susceptible to heart failure and sudden death. Treatment To prevent the onset of the disease, avoid exertion, excitement, and sudden exertion. Drugs that enhance myocardial contractility, such as digitalis, beta-agonists such as isoprenaline, and drugs that reduce cardiac load, such as nitroglycerin, aggravate left ventricular outflow tract obstruction and should not be used as much as possible. Surgical treatment Commonly used surgical methods include: 1. Combined aortic and left ventricular incision myocardial resection: median sternal incision, application of extracorporeal circulation combined with hypothermia, placing a decompression drain in the left atrium, blocking the ascending aorta, injecting cold cardiac arrest fluid under pressure at its root and locally lowering the myocardial temperature, incising the root of the ascending aorta laterally, pulling the right coronary valve forward with a pulling hook, and removing the U-shaped myocardium from the front of the ventricular septum with a round-bladed knife. The U-shaped myocardium is removed with a round-bladed knife from the anterior ventricular septum, starting below the right coronary valve and extending to the left below the junction of the right and left coronary valves. It is important not to extend the septal incision to the right, as this may damage the left atrioventricular bundle and cause complete conduction block. The septal rectangular myocardial slice is elongated inferiorly under direct visualization, but must not be cut too deeply. Another oblique incision of approximately 4 cm in length parallel to the lowest oblique branch is made in the lower part of the anterior wall of the left ventricle to enter the left ventricular cavity below the anterior papillary muscle, and the anterior valve leaflet is pulled to the left side of the ventricular septum through the incision, and the hypertrophied myocardium of the ventricular septum is removed from below and upward with a small knife to join the transaortic resected myocardial piece, and then the whole hypertrophied myocardium is cut off. embolism. The full myocardial incision is intermittently sutured, and the aortic incision is sutured. The left ventricular cavity and residual gas in the aorta are drained, the aortic blocking forceps are removed and the body temperature is raised, and the extracorporeal circulation is stopped after a strong heartbeat. 2, transaortic incision ventricular septal myocardial resection and dissection: establish extracorporeal circulation and take myocardial protection measures, block the aortic blood flow through the root of the ascending aorta transverse incision, traction right coronary valve to reveal the ventricular septum, use a small circular knife to make two parallel incisions in the upper part of the ventricular septum below the right coronary valve, when cutting the lower part of the ventricular septum can compress the right ventricular free wall, so that the ventricular septum moves to the left ventricular cavity to improve the exposure, and then The rectangle of hypertrophic myocardial tissue between the two parallel incisions was excised. Finger pressure is applied to the septal incision to increase the depth and width of the septal groove, remove the myocardial debris, suture the aortic incision, drain the left ventricular cavity and intra-aortic gas, and remove the aortic blocking clamp. If the myocardial resection of the hypertrophied ventricular septum is still considered unsatisfactory, the myocardium can be completely resected via the left ventriculotomy route. Interventional treatment Chemical ablation is used to ablate the hypertrophied septal muscle, which requires a suitable septal branch vessel.