Cardiologists should be familiar with the basic principles and main methods of echocardiography, grasp the advantages and shortcomings, analyze the reported results more objectively, dynamically observe the changes in each measurement data, and combine them with comprehensive clinical analysis to avoid over-reliance on ultrasound diagnosis. Moreover, we should communicate more with the ultrasonographer, fill out the examination application form carefully, provide the necessary clinical information, and preferably analyze the images together with the ultrasonographer in difficult cases. Because, the ultrasound results must be based on clinical practice. In fact, the founder of echocardiography, Feigenbaum, was a cardiologist. In foreign countries, echocardiography is part of the cardiology department, and all cardiologists need to undergo special training in echocardiography, not only to have the ability to analyze the ultrasound images of the heart, but also to have hands-on skills. However, the majority of hospitals in China have always left it up to ultrasound doctors to perform this examination, resulting in cardiologists not understanding the basic knowledge of echocardiography and not being able to accurately understand and judge echocardiography reports; ultrasound doctors, lacking clinical expertise, have difficulty in providing the necessary information required by the clinic in an objective manner. Therefore, training cardiologists with basic skills in cardiac ultrasound and returning echocardiography to cardiology is an inevitable trend in the development of the discipline. Achieving this integration requires the full participation of cardiologists in echocardiography training. The ability to accurately interpret echocardiograms becomes the key to measuring outcomes. Mastering the basics of echocardiography and clarifying the clinical value 1. Common examination methods of echocardiography Two-dimensional echocardiography shows the cross-sectional anatomical structure and spatial relationship of cardiac great vessels in real time, using three basic planes perpendicular to each other with the heart, which becomes the necessary basis for echocardiographic examination. M-mode echocardiography clearly shows the rapid activity changes in the local tissues of the heart, based on two-dimensional echocardiographic images, and the desired M-mode echocardiographic image is selected by adjusting the sampling line. Doppler echocardiography uses the Doppler effect to study the hemodynamic changes of the heart. The blood flow is color-coded in real time in the two-dimensional ultrasound section via the sampling frame, with red indicating blood flow toward the probe and blue indicating blood flow away from the probe. 2.Echocardiography basic functions Echocardiography can qualitatively diagnose and quantitatively analyze the heart structure, valve morphology, ventricular wall motion and hemodynamic status. 3.Assessment of cardiac morphology and structure including chamber size, ventricular wall thickness, valve opening and closing, and myocardial motion. Cardiologists should master the knowledge: the left ventricular internal diameter measured by two-dimensional ultrasound is smaller than the M-mode measurement, and the normal upper limit is usually not more than 55 mm; the normal value of the left atrial volume index is (22±6) ml/m2; the normal upper limit of the right atrial transverse diameter is 44 mm; the right ventricular transverse diameter should be smaller than the left ventricle (the middle <35 mm, the base <42 mm); the right ventricular free wall thickness is usually <5 mm; the right ventricular outflow tract The upper limit of normal value is 33 mm; the upper limit of normal value of pulmonary artery is 23 mm; the upper limit of normal value of aortic sinus is 33 mm; the upper limit of normal value of septal and posterior left ventricular wall thickness is 11 mm. hemodynamic monitoring is performed to assess the output per beat and cardiac output; to evaluate the degree of valve stenosis and insufficiency; the direction, velocity, and pressure difference of atrial, ventricular, and aortic shunts; and to estimate the systolic and diastolic pulmonary artery pressure. The clinical symptoms of pulmonary hypertension are non-specific, and the etiology is multidisciplinary and prone to misdiagnosis, making echocardiography an indispensable and important screening method. Evaluation of cardiac systolic and diastolic function The overall systolic function of the left ventricle is determined by the left ventricular ejection fraction (LVEF), which is normally not less than 55%, but it should be noted that mitral regurgitation above a moderate level may overestimate the result. LVEF: 45% to 54% indicates mild abnormalities in left ventricular systolic function, 30% to 44% indicates moderate abnormalities, and <30% indicates severe abnormalities. The main parameters of LV diastolic function: mitral antegrade flow spectrum E peak, E deceleration time (DT), A peak, and E/A peak ratio; mitral annular tissue Doppler spectrum E' peak, A' peak, and E'/A'; E/E ' peak; pulmonary venous flow spectrum S-wave, D-wave, and inverse a-wave (Table 1). Reading echocardiographic reports for rational planning of treatment strategies A complete echocardiographic report should include four aspects: basic measurements, description of phenomena, ultrasound images, and conclusions. When clinicians see an echocardiogram report, they should not only pay attention to the conclusions given by the echocardiographer, but also read the specific descriptions in the report sheet carefully to obtain information that can help diagnose or differentiate the diagnosis and deepen their understanding of the pathophysiological changes of heart diseases so that they can reasonably formulate treatment plans. Echocardiography report findings can be categorized into three types. 1. There are clear etiological hints: e.g. heart valve disease, congenital heart disease, hypertrophic cardiomyopathy, coronary ventricular wall tumor, infective endocarditis flab formation, etc. For heart valve disease, clinicians should focus on the morphologic features of the valve, including the presence of valve thickening, calcification, restriction of motion, malalignment, prolapse, and tendon rupture; the degree of valve stenosis or regurgitation; and the size of the heart chambers, ventricular wall thickness, cardiac function, and pulmonary artery pressure. For congenital heart disease, especially complex cardiovascular anomalies, attention must also be paid to the visceral-atrial position, atrial-ventricular position, atrioventricular connection, the orientation of the great arteries and their connection with the ventricles, major anomalies and combined anomalies, etc. 2. Only the phenomena are described: e.g., left ventricular enlargement, right ventricular hypertrophy, segmental ventricular wall motion abnormalities, pulmonary hypertension, pericardial effusion, and cardiac occupancy. Clinicians need to combine medical history and laboratory tests to determine the possible causes and develop treatment strategies. 3. Cardiac morphologic and structural changes seen by ultrasound do not match or contradict the hemodynamic information, and other imaging tests are usually required. For example, we encountered a case of a 42-year-old diabetic patient who had only a small atrial septal defect on routine cardiac ultrasound during hospitalization, but the extent of the septal defect did not match the degree of right ventricular enlargement, and further cardiac CT 3D reconstruction suggested ectopic drainage of the left pulmonary vein. This case is a warning: when the hemodynamic abnormalities shown by ultrasound do not match the morphological changes of the heart, the ultrasonographer should be alert and indicate in the report findings; the clinician should actively improve the relevant tests in conjunction with the clinical and reference report findings to clarify the etiology and avoid misdiagnosis and mistreatment.