1, the concept of syncope Syncope is a symptom of a brief, self-limiting loss of consciousness that often leads to fainting. The mechanism of syncope is transient cerebral ischemia, which occurs relatively quickly and is followed by automatic and complete recovery. Some syncope has aura symptoms, but more often the loss of consciousness occurs suddenly and without aura symptoms. Usually, with the recovery of syncope, behavior and orientation are immediately restored. Retrograde amnesia may sometimes occur, mostly in older patients. Sometimes recovery from syncope may be followed by significant weakness. Typical syncopal episodes are brief, and the time to complete loss of consciousness in vasovagal syncope is usually less than 20 seconds. Individual syncopal episodes can last longer than several minutes. 2. Classification of syncope: neurally mediated syncope ——- vasovagal syncope ——- carotid sinus syncope ——- situational syncope (acute bleeding/coughing and sneezing/gastrointestinal irritation/swallowing/defecation/abdominal pain/post-urination/post-meal/weight lifting/brass instrument playing) ——- glossopharyngeal neuralgia upright hypotensive syncope —— autonomic dysregulation —— drug or alcohol induced upright syncope —— hypovolemia (bleeding/diarrhea) arrhythmic syncope ——– sinus node dysfunction ——– atrioventricular conduction system disorders ——– paroxysmal supraventricular and ventricular tachycardia ——– hereditary arrhythmias (e.g., long QT syndrome, Brugada syndrome, etc.) ——– Dysfunction with antiarrhythmic device (pacemaker/ICD) ——– Drug-induced arrhythmias Syncope due to organic heart disease or cardiopulmonary disorders ——- Obstructive heart valve disease ——- Acute myocardial infarction, ischemia ——- Hypertrophic obstructive cardiomyopathy ——- Atrial mucinous aneurysm ——- Aortic coarctation ——- Pericardial disease, pericardial compression ——- Pulmonary embolism, pulmonary hypertension Cerebrovascular syncope ———– Vascular steal syndrome