Hemodynamic measurements for evaluating vasovagal syncope in the emergency department.

Syncope is a sudden and transient loss of consciousness and postural tone, with spontaneous recovery without medical intervention. It accounts for 1.0% to 1.5% of emergency department (ED) visits and up to 6% of hospital admissions. Vasovagal syncope may be the cause of syncope in 21% to 40% of cases. A 53-year-old Chinese woman was brought to the ED by ambulance after a near-syncope episode while performing gentle morning exercises. She was hypotensive and bradycardic in the ambulance. Upon arrival at the ED, her blood pressure was 89/61 mmHg. The use of a Doppler cardiac output monitor readily demonstrated that the patient's systemic vascular resistance was reduced, with cardiac output at the lower limit of the normal range. These hemodynamic data were useful in supporting the diagnosis of vasovagal syncope; they helped in the risk stratification of our patient with syncope, and guided the management and subsequent disposition decision.