Optimal time for brachial artery occlusion of periphral artiral volume to assess endothelial function

Abstract Backgroud: The aim of the study was to evaluate PAV technique in clinical work scenario, which was a novel fingertip non-invasive detection, defined the optimal brachial artery blocking time on the basis of selecting the best reactive hyperaemic index. With the extension of brachial artery blocking time, the degree of reactive hyperemia will increased gradually and tended to be stable. This study will evaluate the different brachial artery blocking time to assess the optimal reactive hyperaemic index(RHI), so as to define the optimal brachial artery blocking time of PAV technology. Methods: Four PAV tests were performed at the same day in 447 subjects who met the inclusion criteria. The brachial artery occlusion time was set at 1,3,5,7 minutes respectively, to define the optimal duration time of blood occlusion to obtain maximum reactive hypermia. The relationship between the ratio of reactive hyperaemic index at the each time period (that is the precentage of RHI measured at 7 minutes) and the measurement time was plotted to evaluate the general trend. RHI were recorded in each group and each time period, and bar charts were drawn according to the mean RHI and standard deviation to analyse whether there were differences of RHI in each group. The PAV measured value obtained in each group and each time period were used to draw dot plots, and the dispersion degree of PAV obtained in each group was analyzed. Results: According to the PAV block time-reactive congestion curve chart, when the block time lasted for 3, 5 and 7 minutes, the curve graph showed an upward trend and tended to be stable. In total data, the average RHI results of 1-minute were significantly different from that of 3-minute, 5-minute and 7-minute(1.29 vs 1.44, p < 0.0001;1.29 vs 1.41, p < 0.0005; 1.29 vs 1.38, p < 0.0080). The PAV had the smallest degree of dispersion and similar coefficients of variation when the blocking time was 3 minutes(31%, 31%, 30%, 29%). Conclusion: At the time of maximum reactive congestion index, combined with the time tolerance of cuff compression acceptable to the subjects, 3-minute was recommended as the optimal time for brachial artery occlusion.