Quantitative photoplethysmography in chronic venous insufficiency: a new method of noninvasive estimation of ambulatory venous pressure.

We estimated ambulatory venous pressure (AVP) noninvasively with a new technique of quantitative photoplethysmography (PPG). Postural changes of hydrostatic pressure permitted in vivo calibration of the PPG. We recorded quantitative PPG and AVP in 14 normal subjects and 14 patients with postthrombotic chronic venous insufficiency. The results were contrasted with qualitative PPG recordings on 41 consecutive patients with chronic venous insufficiency. All but one of the latter patients demonstrated a decrement in skin blood content with exercise of the calf muscle, and shortened recovery time ws the only significant indicator of venous disease. Quantitative PPG correlated closely with AVP with respect to both estimated drop in superficial venous pressure (r = 0.97, P less than 0.001) and recovery time (r = 0.98, P less than 0.001). PPG estimates of intravenous pressure in normal and postthrombosis patients, 42 +/- 10 and 62 +/- 18 mm Hg, respectively, agreed with AVP measurements, 39 +/- 9 and 61 +/- 18 mm Hg, respectively. Quantitative PPG may prove to be an accurate estimate of AVP in patients with suspected chronic venous insufficiency.