The Different Photoplethysmographic Patterns Can Help to Distinguish Patients With Primary and Sclerodermic Raynaud Phenomenon

Introduction: The aim of this study is to investigate pulsatility of digital arteries of hands by means of photoplethysmography (PPG) in patients with primary Raynaud phenomenon (PRP) and systemic sclerosis (SSc) and to compare the results with those obtained in healthy controls. Methods: One hundred five patients with SSc, 96 patients with PRP and 85 healthy controls were recruited in this study. Nailfold videocapillaroscopy and PPG were performed in healthy controls and patients. In patients with SSc, the capillaroscopic pattern was classified as early, active and late group pattern. A baseline PPG was recorded simultaneously in all 10 fingers of the hands. The photoplethysmographic curves were evaluated for morphology and amplitude of sphygmic wave. Results: In healthy controls group, PPG shows the presence of photoplethysmographic homogeneous pattern and high mean value of sphygmic wave amplitude. In PRP group, PPG demonstrates homogeneous photoplethysmographic pattern and low mean value of sphygmic wave amplitude. Finally, in the SSc group, photoplethysmographic pattern is dyshomogeneous, and the mean value of sphygmic wave amplitude is intermediate between the other 2 groups. The PPG findings are different in the 3 capillaroscopic groups of patients with SSc and 2 subsets of disease. Conclusion: PPG represents a technique noninvasive to evaluate simultaneously in all 10 fingers of hands digital arteries pulsatility. PPG improves the evaluation of vascular damage in patients with primary and sclerodermic RP.