The role of hemodynamics and duplex ultrasound in the diagnosis of peripheral arterial disease.

Recent reports have suggested that duplex ultrasound should replace hemodynamic measurements and the use of the ankle-to-arm systolic blood pressure ratio in evaluating patients with peripheral arterial disease. Measurement of peripheral hemodynamics in patients with peripheral arterial disease is well established and can be used for screening populations at risk for peripheral arterial disease; the finding of an abnormal ankle-to-arm ratio is associated with a high risk of cardiovascular morbidity and mortality. With the ankle-to-arm ratio, the diagnosis of vascular disease can be established in symptomatic patients and initial treatment plans can be formulated. In contrast, duplex ultrasound provides accurate information on vessel morphology and changes in blood-flow velocity in specific areas of stenosis. The test is noninvasive, and in some situations the duplex instrument may be superior to an angiogram in detecting patent distal vessels. Because it is more expensive and time-intensive than measuring peripheral pressures, duplex ultrasound should be used in selected patients in whom the knowledge of actual vessel morphology is critical to the patient's treatment.