Distal systolic branch blockage is life-threatening. The distal branch of the rotary branch belongs to a relatively thin blood vessel, the area of myocardial infarction after the blockage of the blood vessel is relatively small, although the infarction area is small, but still may induce malignant arrhythmia, resulting in the occurrence of sudden death. Rotary branch blockage is a serious complication of coronary heart disease, the onset of the basis of coronary atherosclerosis, on the basis of coronary atherosclerosis there is a serious narrowing of the coronary arteries, resulting in acute myocardial infarction caused by vascular blockage. Patients with myocardial infarction should go to the hospital in time to improve coronary angiography, quickly open the occluded blood vessels, reduce the scope of myocardial necrosis, reduce the risk of sudden death.