Digital blood flow in systemic sclerosis

Abstract

Digital vascular status in 10 untreated patients suffering from systemic sclerosis for 1 to 4 years was evaluated by a method called photoplethysmography (PPG). The PPG probe was attached serially to the distal phalanges of all the digits of four limbs with Velcro-strap at an ambient temperature of 28° C - 32° C and humidity of 60-65 percent to record PPG tracings. Six patients (Group A) had clinical symptoms and signs of vascular impairment whereas 4 patients (Group B) did not have. Diminished vascular flow was seen in all the patients of both the groups. On an average, 9 digits (45%) in Group A and 7 digits (35%) in Group B had reduced blood circulation. The difference between the two groups was not statistically significant (p>0.5). Degree of vascular impairment had no bearing upon the duration of the disease (rxy=+0.41). Impairment of digital blood flow may be due to organic narrowing of digital artery, functional vasomotor changes, endothelial proliferation and damage, blood hyperviscocity and less deformable red blood cells.