Effect of sinusoidal leg cycling exercise period on brachial artery blood flow dynamics in humans

Abstract

Purpose: To quantify the dynamics of blood flow in brachial artery (BF-BA) in response to sinusoidal work rate (WR) leg cycling exercises of 2-, 4-, and 6-min periods and to examine their relationship with the forearm skin blood flow (SBF). Methods:Seven healthy young male subjects performed upright leg ergometer exercise with a constant WR (mean sinusoidal WR) for 30 min followed by sinusoidal WR exercise of three different periods (number of repetitions): 2 min (7), 4 min (4), and 6 min (3). The WR fluctuated from 20 W to a peak WR corresponding to 60% peak oxygen uptake (VO 2 ). We continuously measured pulmonary gas exchange, heart rate (HR), blood velocity and cross-sectional area of BA, and forearm SBF and sweating rate (SR).Results: All variables were followed by the sinusoidal WR. The phases of the variables for gas exchange and central circulation, such as VO 2 and HR with WR forcing were similar (e.g., phase shift (θ) in HR [°]: 2 min, 60 ± 7; 4 min, 45 ± 10; 6 min, 37 ± 8; mean ± SD) to previous study results, that is, a longer period showed a shorter θ and larger amplitude of responses. Contrarily, the BF-BA response showed anti-phase (approximately 180°) regardless of the period, whereas the θ of forearm SBF and SR were similar to gas exchange and central circulation. Conclusions:Inactive limb BF-BA during sinusoidal leg cycling exercise was out of phase relative to the regulation of O 2 -delivery to active muscles and thermoregulation. The response of BF-BA seems to not always reflect the response of forearm SBF in the downstream area.

Developing an automatic brachial artery segmentation and bloodstream analysis tool using possibilistic C-means clustering from color doppler ultrasound images

“…Thus, it is regarded as a good blood vessel health predictor of cardiovascular disease [6][7][8][9]. Not only for cardiovascular disease patients, is FMD-related blood flow dynamics in brachial artery related with the effect of sports activities in health [10][11][12]. A recent report also confirmed that the brachial artery diameter and FMD were significantly [13].…”