Decreased compliance in the deep and superficial conduit veins of the upper arm during prolonged cycling exercise

Abstract

We examined whether there is a difference in compliance between the deep and superficial conduit veins of the upper arm in response to prolonged exercise. Eight young men performed cycling exercise at 60% of peak oxygen uptake until rectal temperature had been increased by 1.1°C for 38-48 min. The cross-sectional area (CSA) of the brachial (deep) and basilic (superficial) veins was assessed by ultrasound during a cuff deflation protocol. Compliance (CPL) was calculated as the numerical derivative of the cuff pressure and CSA curve. During prolonged exercise, CPL in both conduit veins was similarly decreased when compared with pre-exercise values; however, the CSA decreased in the deep vein but increased in the superficial vein. In addition, passive heating caused an analogous change in CSA and CPL of superficial vein when compared with prolonged exercise, but did not change CSA and CPL of deep vein. Cold pressor test induced the decreased CSA of deep and superficial veins without the alteration of CPL of both veins. These results suggest that CPL in the deep and superficial conduit veins adjusts to prolonged exercise via different mechanisms.

Keywords: Conduit vein; cross‐sectional area; cuff deflation protocol; ultrasound technique.

Figure 1

Cuff pressure–cross sectional area (CSA) curves and cuff pressure–compliance (CPL) relations in deep and superficial veins at pre‐exercise and during prolonged exercise. Values are mean ± SE. Probability given by two‐way ANOVA are shown in figures of A–D; Condition, main effect of pre‐exercise and exercise; Cuff pressure, main effect of cuff pressure; Interaction, interaction effects. * Significant difference between pre‐exercise and during exercise in post hoc test, P < 0.05.

Figure 2

Effect of passive heating without exercise on cross‐sectional area (CSA) and compliance (CPL) in deep and superficial veins. Values are mean ± SE. Probability given by two‐way ANOVA are shown in figures of A–D; Condition, main effect of CON and HOT; Cuff pressure, main effect of cuff pressure; Interaction, interaction effects. * Significant difference between CON and HOT in post hoc test, P < 0.05.

Figure 3

Effect of cold pressor test on cross‐sectional area (CSA) and compliance (CPL) in deep and superficial veins. Values are mean ± SE. Probability given by two‐way ANOVA are shown in figures of A–D; Condition, main effect of rest and cold pressor test; Cuff pressure, main effect of cuff pressure; Interaction, interaction effects. * Significant difference between rest and cold pressor test in post hoc test, P < 0.05.