Exertional syncope suggests cardiac outflow tract obstruction, mainly due to aortic stenosis. This syncope reflects cerebral ischemia caused by the simultaneous dilatation of peripheral vessels due to the inability to increase cardiac output during exertion. Prolonged syncope can cause seizures. Typical syncopal episodes are brief, with loss of consciousness rarely lasting more than 20-30 seconds. Some syncopal episodes are preceded by prodromal symptoms such as dizziness, tinnitus, sweating, blurred vision, pallor, and general malaise; this period is called the prodromal phase. After the attack, symptoms such as fatigue and weakness, nausea, vomiting, drowsiness, and even incontinence occur, which is called the recovery period. Therefore, the entire course of syncope may last for several minutes or longer. Syncope usually does not produce retrograde amnesia, and disorientation and correct behavior often return rapidly. Labor syncope often occurs immediately after exercise, and prolonged syncope can cause seizures.