Blood flow in fingers in generalized scleroderma with Raynaud's phenomenon: influence of arterial blood pressure reduction and proximal vasodilatation.
Maximum reactive hyperemia following vascular occlusion can be taken as an estimate of tissue blood flow capacity. Ten patients with generalized scleroderma and Raynaud's phenomenon and 7 normals were studied. Blood flow was estimated in subcutaneous tissue of fingers by the local 133Xenon washout technique. Blood pressure cuffs were applied around the upper arm and a finger just proximal to the 133Xenon depot. Blood flow was estimated before and after inflation of each cuff. Decrease in arterial perfusion pressure head in fingers was obtained in 3 ways, viz. (a) by proximal vasodilatation, (b) by elevation of the limb, and (c) the combination of (a) and (b). At heart level, maximum 133Xenon washout rate was always lower when the whole arm participated in the hyperemia illustrating the effect of proximal vasodilatation. Maximum blood flow was significantly decreased in the patients as compared to normals. When the fingers were elevated by 40 cm, reactive hyperemia disappeared in the patients. In normals, hyperemia was not abolished until the fingers were elevated by 60 cm. This simple maneuvre might be a suitable provocation test showing the effect of a decrease in arterial perfusion pressure, when organic vascular stenosis exists. Seemingly unimportant lowerings of systemic blood pressure probably are followed by similar changes in finger blood pressure in the patients where they may represent a drastic reduction in blood pressure. This effect may have consequences for the use of systemic vasodilator drugs in late scleroderma.
D001794:Blood Pressure; D005385:Fingers / Q000098:blood supply*; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology; D011928:Raynaud Disease / Q000503:physiopathology*; D012039:Regional Blood Flow; D012595:Scleroderma, Systemic / Q000503:physiopathology*; D014664:Vasodilation