[Analysis of forearm circulation--a substitute for 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 desirable to non- or semi-invasively evaluate blood flow regulation and its impairment by atherosclerotic processes. Indeed, endothelial dysfunction of the coronary arteries parallels endothelium-related impairment of vasoreactivity of the brachial artery. Analysis of flow-dependent dilatation 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 in a semi-invasive way. The endothelium-mediated forearm blood flow response is obtained by the infusion of acetylcholine into the brachial artery, whereas infusion of sodium-nitroprusside provides information about the endothelium-independent vasodilator capacity of the forearm resistance vasculature. Assuming that the atherosclerotic process is a generalized disease, the assessment of the forearm blood flow by venous strain gauge occlusion plethysmography may provide some information applicable to the coronary circulation. However, the proof of a positive correlation between the degree of the impaired forearm blood flow responses measured by occlusion plethysmography and the extent of coronary atherosclerosis and its disturbed vasoregulation remains to be established.