Measurement of Arterial and Venous Reactivity by an Advanced Strain Gauge Plethysmograph

Abstract

A bstractThe problems of applying mercury strain gauge venous occlusion plethysmography in quantitative measurements of high blood flow rates were studied in the extremities of humans and animals. The fast-acting ECG-controlled pneumatic Periflow system opens the possibility of measurements with reduced restriction of arterial inflow. In animal experiments the arterial inflow rate (about 0.25 vol%/min) during the arterial occlusion period was estimated by an indicator dilution technique. The accuracy of the perfusion rate estimation of a limb by plethysmography was tested in controlled perfused extremities of large dogs weighing about 60 kg. Strain gauges with different positions showed different—but for each filament quite proportional—relations to real values. The nonuniform venous capacities of the different segments of a limb, which have been shown by injections of a known volume and recording of pressure volume curves, may complicate blood flow measurements by volume displacements from low-compliance regions to high-compliance regions of the vein system. Estimations of the length resistance relation of mercury strain gauges agreed well with the theoretically expected function. If an inextensible part is inserted into the circumferential arrangement of the filament, a correcting calculation of volume changes is necessary.

Angiogenesis in Skeletal Muscle Precede Improvements in Peak Oxygen Uptake in Peripheral Artery Disease Patients

“…First, we used five minutes of cuff occlusion during the plethysmography evaluation for post-hyperemic blood flow. Though this has been used by others 21,22,23 this is not a perfect measure of femoral artery endothelial function or true max flow measured with absolute minimum vascular resistance. A second limitation is that although we did not detect changes in CS or myoglobin with supervised exercise, we did not measure all proteins of oxidative metabolism and we cannot exclude that possibility that other proteins might be regulated in a different manner.…”

“…21,22,23 The involved leg (lowest ABI) was supported just above the level of the heart, and a mercury-in-Silastic strain gauge was placed around the widest part of the calf. Prior to all assessment an ankle cuff was inflated to 50 mmHg above systolic pressure for the 60 seconds to eliminate foot circulation from the measurement.…”

Can venous occlusion plethysmography be used to measure high rates of arterial inflow?

“…When arterial inXow is »20 mL min ¡1 100 mL ¡1 , venous pressure may reach cuV pressure in just a few seconds (Brown et al 1966). Indeed in dogs with arterial inXows as low as »8 mL min ¡1 100 mL ¡1 , venous pressure may reach a cuV pressure of 70 mmHg within just two cardiac cycles during occlusion (Hellige et al 1979). This is in agreement with the Wndings of Tschakovsky et al (1995) who compared FBF with and without venous cuV inXation to 50 mmHg using Doppler ultrasound following dynamic handgrip exercise that had elevated FBF to 22-24 mL min ¡1 100 mL ¡1 .…”

Relationship between leg muscle capillary density and peak hyperemic blood flow with endurance capacity in peripheral artery disease

“…In a subset of (48 PAD and 47 normal) subjects, calf muscle peak hyperemic blood flow was measured in the supine position by venous occlusion strain-gauge plethysmography (DE Hokanson, Issaquah, WA) at rest and during reactive hyperemia (RH) immediately after release of 5 min cuff occlusion, as described below (15). The most severely diseased leg was supported just above the level of the heart, and a mercury-in-Silastic strain gauge was placed around the widest part of the calf.…”