The causes of sudden death are many, and the common ones include the following: 1. Acute myocardial infarction, which is a very serious disease that can cause sudden death due to sudden blockage of the blood vessels supplying the heart, resulting in sudden necrosis of a large amount of heart muscle. 2. Malignant arrhythmias, such as supraventricular tachycardia exceeding 200 beats a minute, ventricular tachycardia exceeding 150 beats a minute, or a heartbeat that is too slow, such as less than 35 beats a minute, are very serious conditions that can cause sudden death. 3. 3. aortic coarctation, a disease in which blood enters between the endothelium and the middle layer due to tearing of the endothelium, can cause sudden death if the coarctation ruptures. 4. pulmonary embolism, especially in patients with deep vein thrombosis of the lower extremities, can also cause sudden death if a large thrombus is dislodged and causes embolism of the main pulmonary artery. The same can cause sudden death.