We aimed to evaluate hemodynamic parameters in the cutaneous microcirculation during recovery to graded dynamic exercise performed on a cycloergometer by using two distinctive methods: high-frequency ultrasound Doppler flowmetry (UDF) and laser Doppler fluxmetry (LDF). Regarding UDF, the medium linear blood flow velocity (Vam) was estimated, expressed in absolute units (cm/s) whereas blood flow assessed by LDF was registered in arbitrary perfusion units (PU). We compared the corresponding perfusion values obtained by UDF and LDF, respectively, every 20 s during recovery period to physical exercise. Three types of microvascular blood flow dynamics were recorded: blood flow with an occasional paroxysm, a pulsatile blood flow pattern, and a shunting-type blood flow pattern. In the first type, the reaction time of registration and the direction of changes of UDF and LDF values coincided in 77.7%, exhibiting high correlation (r = 0.77; p≤0.001). In the second type, the direction of changes of UDF and LDF showed 85.0% similarity and a moderate correlation (r = 0.66; p = 0.0015), whereas in the third type, there was also a moderate correlation (r = 0.53, p = 0.0024). Our pilot experiments have shown that UDF could be regarded as a comparable substitutional method to LDF for studying skin microcirculation.
Keywords: Microcirculation; high-frequency Doppler sonography; laser Doppler fluxmetry; physical exercise; ultrasound Doppler flowmetry.