ANALYSIS OF FOREARM BLOOD-FLOW - A SURROG ATE FOR THE DIAGNOSIS OF CORONARY ATHEROSCLEROSIS

The vascular endothelium plays a central role in the regulation of the arterial tone and in the control of the local hemostasis. It is also involved in the regulation of proliferation processes of the vascular wall. The presence of risk factors for coronary artery disease and/or manifest atherosclerotic lesions are associated with an impairment of endothelium-dependent vasoregulation. Since the assessment of coronary vascular reactivity requires an invasive approach, it would be desira ble to non-or semi-invasively evaluate blood now regulation and its im pairment by atherosclerotic processes. Indeed, endothelial dysfunction of the coronary arteries parallels endothelium-related impairment of vasoreactivity of the brachial artery. Analysis of flow-dependent dila tation of the brachial artery by means of ultrasound represents a non- invasive diagnostic tool to assess endothelium-mediated vasomotion. By means of venous strain gauge forearm occlusion plethysmography. it is possible to measure the blood flow ina semi-invasive way. The endothe lium-mediated forearm blood flow response is obtained by the infusion of acetylcholine into the brachial artery whereas infusion of sodium n itroprusside provides information about the endothelium-independent va sodilator capacity of the forearm resistance vasculature. Assuming tha t the atherosclerotic process is a generalized disease, the assessment of the forearm blood flow by venous strain gauge occlusion plethysmog raphy may provide some information applicable to the coronary circulat ion. However, the proof of a positive correlation between the degree o f the impaired forearm blood flow responses measured by occlusion plet hysmography and the extent of coronary atherosclerosis and its disturb ed vasoregulation remains to be established.