Cardiac

Concussion is a syncope induced by a sudden decrease in cardiac output and cerebral ischemia. Severe cases can cause sudden death during a syncope and are the most severe type. The presence of organic heart disease is the most critical factor affecting the prognosis of patients with syncope. Patients with organic heart disease or left ventricular dysfunction should be alert to the risk of sudden death if syncope occurs. According to foreign reports, the one-year mortality (18-33%) of patients with cardiogenic syncope is significantly higher than that of patients with non-cardiogenic syncope (0-12%) or patients with unexplained syncope (6%). But this difference is mainly determined by the type of heart disease rather than syncope. Most cardiogenic syncope has nothing to do with body position (except for some special diseases such as atrial myxoma), and there are few prodromes, which may be accompanied by cyanosis, dyspnea, arrhythmia, weak heart sounds and corresponding ECG abnormalities. Heart diseases that cause cardiogenic syncope can be divided into three categories: arrhythmia, obstruction of cardiac output, and myocardial disease.