By a large heart wound, a small pericardial wound or a blockage of blood clots in the tissue around the wound. Acute intrapericardial bleeding of 100-200 ml can cause a sharp rise in pressure in the pericardial cavity, which affects the normal diastole of the heart and produces acute pericardial compression signs. The first to be pressurized are the vena cava and atria, resulting in an increase in central venous pressure and end-diastolic pressure, and a gradual rise in peripheral venous pressure. Initially, the blood pressure is normal or slightly elevated due to reflex constriction of the peripheral vessels. When the heart is severely restricted in diastole, the blood volume per beat is significantly reduced and the arterial pressure falls rapidly. When the pressure in the pericardial cavity rises to 17 cmH2O, no blood is discharged from the heart beat, and the patient quickly enters shock symptoms unless the venous pressure is increased by rapid rehydration. On the one hand, acute cardiac pressure blockage decreases the blood discharge from the heartbeat and affects the blood supply of coronary arteries, leading to myocardial hypoxia, sudden loss of cardiac function and failure. On the other hand, pericardial compression can delay lethal hemorrhage in the early stage, or make myocardial fissure bleeding stop temporarily, which provides valuable time to save the patient’s life. Symptoms of acute pericardial compression include peripheral cold sweat, cyanosis of the face and lips, shortness of breath, raging superficial neck veins, decreased blood pressure, fine and rapid pulse, and odd pulse. The classic Beck’s triad: distant heart sounds, decreased systolic blood pressure and elevated venous pressure when present, is helpful in the diagnosis of acute pericardial compression. However, only 35% to 40% of patients generally have all the typical symptoms. In fact, elevated venous pressures appear earliest and decreased arterial pressures appear later. Because the amount of blood in the pericardium is low in pericardial compression due to penetrating cardiac injury, and blood collects in the posterior pericardial cavity of the heart in the supine position, distant heart sounds are less common, but odd pulses are more common.