The Effect of Cuff Occlusion Protocols on Radial Strain and Arterial Haemodynamics

Abstract

The purpose of this study is to compare arterial vasodilation in response to two occlusive cuff positions and various protocols under reactive hyperaemic stimulus. For determining the optimal reactive hyperaemia protocol we studied 10 healthy young adults and calculated the relative strain and haemodynamic changes of the left brachial artery with motion estimation from sequential ultrasonic images and Doppler sonograms. The results from two occlusion cuff positions (left proximal upper arm and distal forearm) showed that brachial artery vasodilation was significantly greater under upper arm occlusion than under forearm occlusion. Results from optimizing reactive hyperaemia protocols showed that the optimum occlusion pressure was 150 mmHg, with an occlusion time of 5 min. The optimum time interval for recording ultrasonic images and estimating relative strain after releasing the cuff was 45-60 s. Use of these conditions resulted in higher vasodilation and larger blood flow changes. We conclude that the magnitudes of relative strain and blood velocity are related not only to the choice of the location of cuff inflation and the magnitude of occlusion pressure and time, but also to the time interval after the release of the occlusive cuff.