Hypertrophic cardiomyopathy is characterized by myocardial hypertrophy. The main pathological change is asymmetric progressive myocardial hypertrophy. According to the location and degree of myocardial hypertrophy, it is divided into two types: (1) hypertrophy of the interventricular septum, which mainly causes outflow tract obstruction, is called hypertrophic obstructive cardiomyopathy; (2) myocardial hypertrophy without outflow tract obstruction is called hypertrophic non-obstructive cardiomyopathy (asymmetric interventricular septal hypertrophy resulting in aortic stenosis under the aortic valve is called idiopathic hypertrophic subaortic stenosis). The disease has a global distribution, with a familial or sporadic onset, and is more common in men than in women, with symptoms appearing earlier and being more severe in women. The majority of patients survive for decades, so the prognosis is good. The prognosis is good. 50% of deaths are sudden. Etiology The cause of the disease is unknown, and the possible factors are: i. Genetic factors. ii. Endocrine disorders: tyrosinoma patients with hypertrophic cardiomyopathy, human intravenous infusion of large amounts of norepinephrine can cause myocardial necrosis. In animal experiments, intravenous injection of catecholamines can cause myocardial hypertrophy. Therefore, some people think that hypertrophic cardiomyopathy is caused by endocrine disorders. Clinical symptoms The main clinical manifestations are dyspnea, angina pectoris, syncope, palpitations, fatigue, cardiac enlargement, and a rough systolic jet murmur in the apical region of the heart and the 3rd and 4th intercostal spaces at the left edge of the sternum. Therapeutic measures Hypertrophic cardiomyopathy develops slowly and has a good prognosis, but due to arrhythmia, it can lead to sudden death, and attention should be paid to avoiding overwork in life, preventing excessive mental stress, and avoiding infections. Therapeutic measures:Mainly include 1, drug therapy 2, pacemaker therapy 3, hypertrophic myocardial ablation therapy 4 Surgery: hypertrophic myocardial resection/incision, mitral valve replacement and heart transplantation. Drug therapy:The goal of treatment is to relieve symptoms and control arrhythmias. 1, β-blockers can make myocardial contraction weakened, reduce outflow tract obstruction, reduce myocardial oxygen consumption, increase diastolic ventricular dilatation, and can slow down the heart rate and increase cardiac output. The earliest application of propranolol is 10mg each time, 3~4 times/d, and gradually increase the dose, in order to improve the symptoms and the heart rate and blood pressure are not low, up to 200mg/d. However, recently it is found that β-blockers can reduce myocardial contraction and outflow tract obstruction. But recently found that beta-blocker therapy can not reduce arrhythmia and sudden death, and does not change the prognosis. 2.Calcium antagonists have both negative inotropic effect to weaken myocardial contraction, but also improve myocardial compliance and favor diastolic function. Verapamil 120～480mg/d, 3～4 times orally, can make the long-term relief of symptoms, low blood pressure, sinus function or atrioventricular conduction disorders should be used with caution. Diltiazem treatment is also effective, the dosage of 30-60mg, 3 times / d. β-blockers and calcium antagonists can reduce side effects and improve the efficacy of treatment. 3.Anti-arrhythmic drugs are used to control rapid ventricular arrhythmia and atrial fibrillation, and amiodarone is more commonly used. When drug treatment is ineffective, electric cardioversion should be considered. 4, the late ventricular systolic function has been impaired and the emergence of congestive heart failure, its treatment and other causes of heart failure the same. 5, drug therapy precautions: Where to enhance myocardial contractility of drugs such as digitalis, β-receptor excitatory drugs such as isoproterenol, etc., as well as to reduce the cardiac load of drugs such as nitroglycerin, etc. to make the left ventricular outflow tract obstruction aggravated, as far as possible not to use. Pacemaker therapy: The therapeutic effect of pacemaker implantation has significant age variability, with elderly patients being better than young patients. The mechanism may be to change the normal cardiac conduction through preexcitation, so that the sequence of septal motion changes to reduce or eliminate the purpose of obstruction. For paroxysmal atrial fibrillation intolerant of medication; or chronic atrial fibrillation not satisfactorily controlled by medication, atrial disassociated node ablation plus pacemaker therapy may help to improve the quality of life. Hypertrophic myocardial ablation: a new treatment in recent years, its mechanism is to infuse a high concentration of alcohol, so that the myocardium in the area of hypertrophic obstruction is necrotic and loses its contractile function, so as to alleviate the effect of obstruction of the flow channel. Surgery: This is currently the most effective treatment for this disease, and is known as the “golden index” for the treatment of this type of disease. It includes hypertrophic myocardial resection/tomy, mitral valve replacement and heart transplantation. Other treatments can control symptoms to some extent in some patients, but a significant number of patients are still incapacitated. And a significant number of patients are unable to receive high doses of medication or medication is ineffective; other treatments are not effective or have failed, so they are more amenable to surgical treatment. Hypertrophic cardiomyopathy can be treated surgically (hypertrophic muscle resection) if there is obstruction (pressure step difference >60 mmHg) and medication or other methods of treatment are ineffective or have failed. In combination with severe mitral valve insufficiency (or SAM sign), concomitant mitral valve replacement may be performed. Patients with end-stage hypertrophic cardiomyopathy may undergo heart transplantation.