The examination methods of pericardial effusion 1.X-ray examination The heart shadow is generally enlarged to both sides (the effusion is more than 300ml); the heart shadow is flask-shaped when a large amount of effusion (more than 1000ml), the superior vena cava shadow is widened, and the heart beat is weak under fluoroscopy. Clear lung field can be distinguished from heart failure. 2.Electrocardiogram There is often low voltage, tachycardia, and alternating voltages are seen in those with large amounts of effusion. 3.Echocardiogram M-type echocardiogram is seen between the anterior wall and after the posterior wall with a dark area of fluid, that is, when the maximum diastolic dark area between the pericardium and epicardium (10 mm, then the accumulation of fluid is small; if between 10 and 19 mm, then it is moderate; if more than 20 mm, then it is large.) M-type echocardiogram is seen between the anterior wall and after the posterior wall with a dark area of fluid, that is, when the maximum diastolic dark area between the pericardium and epicardium The maximum diastolic dark area (at 10 mm, the fluid accumulation is small; if it is between 10 and 19 mm, it is moderate; if it is greater than 20 mm, it is large). 4.Pericardiocentesis can confirm the presence of pericardial effusion and relieve the symptoms of pericardial tamponade. A portion of the effusion is retained for laboratory tests of relevant etiology.