The immediate effect of physical activity on ultrasound-derived venous reflux parameters.

OBJECTIVE

Ultrasound-derived reflux volume (RV) has a low correlation with the clinical severity of chronic venous disease, as well as other hemodynamic parameters. The difference in methodology of measurements could be a possible explanation. The purpose of this study was to investigate the immediate effect of calf pump activity used in the functional methods on ultrasound-measured venous reflux parameters.

METHODS

Patients with primary incompetence of the great saphenous vein (GSV) were recruited for the study. The diameter of the GSV, cross-sectional area in square centimeters, time average velocity in centimeters per second, and reflux duration (RT) in seconds were measured by duplex ultrasound examination. The RV flow rate (Q) in milliliters per second and RV in milliliters were calculated. The measurements were performed standing at rest before and 60 seconds after physical exercise (30 lifts to tiptoes at a frequency of 1 time per second). A decrease in the volume of reflux after exercise was calculated (DRV = RV [after] - RV [before]/RV [before] × 100%.) Automatic distal compression-decompression (120 mm Hg) was used as a provocation maneuver.

RESULTS

There were 61 patients included in the study. Before exercise, reflux parameters were: RT = 4.85 seconds (interquartile range [IQR], 3.71-6.00 seconds); Q = 3.89 mL/second (IQR, 2.03-5.81 mL/second); and RV = 17.05 mL (IQR, 10.32-25.34 mL). After physical exercise, they changed to RT = 2.86 seconds (IQR, 2.14-3.33 seconds); Q = 3.61 mL/second (IQR, 2.06-6.37 mL/second); RV = 10.07 mL (IQR, 6.08-16.48 m:); and DRV = 40.9%. The changes in RT and RV values were statistically significant. DRV was inversely related to both the GSV diameter and the Venous Clinical Severity Score (r = -0.56, and r = -0.41, respectively; P < .0001).

CONCLUSIONS

Venous reflux decreases within 1 minute after the end of the exercises. Reduction of the volume of retrograde flow occurs only owing to the shortening of reflux time, and not the flow rate, suggesting that venous reflux is influenced by exercise-induced changes in the volume of the venous reservoir.