Value of finger arterial blood pressure in diagnosis of vascular changes in some connective tissue diseases.

This study was performed in 60 patients with the following connective tissue diseases: rheumatoid arthritis (RA--20 patients), systemic lupus erythematosus (SLE--20), and progressive systemic sclerosis (scleroderma = PSS--20). Twenty normal persons served as controls. All patients and controls were subjected to complete history taking, complete physical examination, and laboratory investigations including: rheumatoid factor, anti-DNA, LE cell test, antinuclear factor (ANF), and ECG. Finger arterial blood pressure (FABP) readings using an 8 MHz Doppler flow detector with a 24-mm-diameter cuff at a temperature of 24 degrees C were made in all cases and controls. The mean age of incidence in patients with RA was 37.8 years; in those with SLE, 21.5 years; in those with PSS 34.6 years; and in the control group, 33.7 years. Women were predominant both in the diseases and the control groups. The FABP was measured in all groups and the range of difference between the brachial and finger arterial blood pressure in each group was estimated. In the control group the mean difference was 27.7 mm Hg; in the RA group, 45.8 mm Hg; in the SLE group, 58.1 mm Hg; and in the PSS group, 70.9 mm Hg. There were no significant peripheral vascular changes in the small arteries in the RA group, whereas in the SLE and PSS groups there was a significant difference, which suggests different underlying microvascular changes. The FABP appears to be a diagnostic tool in the diagnosis of PSS and it helps in differentiation between various types of collagen disease in equivocal cases.