Venous occlusion plethysmography versus Doppler ultrasound in the assessment of leg blood flow during calf exercise

Abstract

This study explored the accuracy with which venous occlusion plethysmography (VOP) assesses the hyperaemic response during calf exercise. Using Doppler ultrasound (DU) as a criterion standard technique, we tested the hypotheses that leg blood flow during contraction is not greater than at rest and that VOP provides similar estimates of the hyperaemic response between contractions as DU. Eleven subjects performed several bouts of calf exercise across a wide range of forces (50-400 N ≅ 6-45%MVC). Each bout consisted of 2 min of intermittent contractions preceded and immediately followed by sustained (40 s) contractions. DU estimates of leg blood flow during the sustained contractions were never significantly greater (P > 0.05) than those measured at rest. Paired (DU and VOP) estimates of leg blood flow (n = 488) were obtained between intermittent contractions and ranged between ~50-900 ml min(-1). There was a strong correlation between these DU and VOP estimates (Pearson r = 0.91; P < 0.05). Ordinary least products regression analysis, with VOP as the y variable, showed a relatively small proportional bias (slope = 0.942; CI = 0.938-0.946) and fixed bias (y intercept = -13.3 ml min(-1); CI = -14.4 to -12.2 ml min(-1)) between the two measurement techniques. Since these small biases can be explained by the slight differences in vascular regions which the two techniques assess, these data suggest that VOP can accurately assess the hyperaemic response to exercise.

Hemodynamic responses during graded and constant-load plantar flexion exercise in middle-aged men and women with type 2 diabetes

“…Blood flow was assessed using venous occlusion plethysmography (VOP). This technique has been shown to provide similar estimates of limb blood flow during calf plantarflexion exercise, very similar to the present protocol, when compared with Doppler ultrasound (10). Briefly, a mercury-silastic strain gauge (Hokanson EC-6) was placed around the widest part of the subject's right calf and connected to the plethysmograph (Hokanson EC-6).…”

“…All participants visited the cardiovascular performance laboratory at Trinity College Dublin on two or three separate occasions separated by at least 48 h. Of the female subjects, six were premenopausal (1 with T2D and 5 nondiabetics), and their testing dates were scheduled to occur during the midfollicular phase of their menstrual cycle (days [5][6][7][8][9][10][11][12]. Before each visit subjects were asked to refrain from consuming caffeine and alcohol in the 24 h prior to testing, in addition to limiting exercise to activities of daily living.…”

Effect of type 2 diabetes on the dynamic response characteristics of leg vascular conductance during exercise

“…53,54 However, recent work from one of our laboratories shows very close agreement between plethysmographic and Doppler ultrasound estimates of leg blood flow during calf exercise. 55 …”

Changes in the peripheral blood flow in legs in response to the cold: own studies using plethysmography

“…Impedance plethysmography has been used in a number of global studies to assess changes in peripheral blood pressure, both in people with cardiovascular diseases and in healthy people, in response to different external impulses. [13][14][15][16] Impedance plethysmography has also been applied to assess the usefulness of blood vessels, e.g., of the forearm, before using them in bypasses of coronary arteries. [10] In traumatology, impedance plethysmography has been used to assess changes in blood flow following the application of low temperature for extremity injuries.…”