synkop

Synkop, also known as syncope in English, is a brief loss of consciousness caused by a temporary reduction in blood flow to the brain. It is typically spontaneous and followed by a rapid return to baseline. Prodromal symptoms such as lightheadedness, nausea, sweating, or blurred vision may occur before the event, especially in reflex or orthostatic forms.

The condition is commonly classified into three main categories: reflex (vasovagal) syncope, orthostatic hypotension–related syncope, and cardiac syncope due to arrhythmia or structural heart disease. Less frequent causes include neurologic disorders or situational events (for example micturition or coughing). Cardiac syncope carries the highest risk of recurrence and adverse outcome.

Prodromal symptoms and triggers help guide assessment but do not always distinguish causes. Risk factors include dehydration, prolonged standing, heat exposure, medications that lower blood pressure, older age, and known heart disease.

Evaluation starts with a careful history and physical examination, including orthostatic blood pressure measurements. Electrocardiography is essential to detect rhythm problems. Additional testing may include ambulatory heart rhythm monitoring, echocardiography, blood tests, and, when indicated, neuroimaging. Red flags requiring urgent evaluation include syncope accompanied by chest pain, palpitations, shortness of breath, neurologic deficits, trauma, or hemodynamic instability.

Management targets the underlying cause. Acute treatment for suspected vasovagal episodes involves placing the person supine with legs elevated and ensuring airway and circulation. Long-term strategies include adequate hydration, gradual position changes, avoidance of triggers, and adjustment of medications. Cardiac syncope may require specific therapies such as antiarrhythmic drugs or pacemaker in selected patients. Prognosis is generally favorable for reflex and orthostatic syncope in otherwise healthy individuals but poorer when a serious cardiac condition is present.