Diagnosis of hypertrophic cardiomyopathy: Primary criteria: (1) Echocardiographic left ventricular wall or (and) septal thickness of more than 15 mm. (2) Hypertrophy in the apical and proximal septal areas with dense myocardium or interstitial arrangement found by tissue Doppler and magnetic resonance. Secondary criteria: (1) Patients within 35 years of age with 12-lead ECG I, aVL, V4.6 lead ST downshift, and deep symmetric inverted T waves. (2) 2D ultrasound septal and left ventricular wall thickness of 11.14 mm. (3) Genetic screening reveals a known mutation, or a new mutated locus, linked to HCM. Exclusion criteria: (1) Systemic disease, hypertensive disease, rheumatic heart disease mitral valve disease, congenital heart disease (atrial septal and ventricular septal defects) and metabolic disease with myocardial hypertrophy. (2) Cardiac hypertrophy in athletes. Clinical criteria for confirming the diagnosis of HCM: Any one of the following: 1) major criteria + exclusion criteria; 1) major criterion + minor criterion 3 i.e. positive mutation; 1) major criterion + exclusion criteria; 2) minor criteria 2 and 3; minor criteria 1 and 3. Diagnosis of FHCM: Two or more members of the immediate family in three generations have a diagnosis of HCM or have the same DNA locus variant, except for those with prior evidence of the onset of the disease. It is important to screen and determine the genetic background after the diagnosis of FHCM and to follow up mutation carriers without clinical manifestations to determine the clinical phenotype in a timely manner, and it is recommended to perform genetic diagnosis and evaluation according to the procedure shown in Figure 2.