Abstract
Finger systolic blood pressure (FSP) was measured by cuff technique before and after local cooling in three groups of patients (Raynaud's disease (7), subclavian stenoses (5), thrombo-angiitis obliterans (15)), and in 15 normals. The response to finger cooling registered as a decrease in FSP indicates an increase of digital arterial tone. In all three groups, digital arterial tone increased more than in normals during finger cooling. Patients with Raynaud's disease showed a pathological increase in arterial tone at 23.5°C with closure of the digital arteries at a mean temperature of 18.5°C. The temperature eliciting these phenomena in patients with thrombo-angiitis obliterans was about 7°C lower (16.5 and 11.0°C, respectively). Accordingly, cold sensitivity and Raynaud's phenomena in the two groups may have a different pathophysiological mechanism, namely a pathological arterial tone in Raynaud's disease vs. a normal arterial tone in obliterative diseases acting on a narrow vessel.