Recording of dynamic arterial compliance changes during hand elevation

Finger arterial compliance has been studied on the beat-to-beat basis by using the digital arterial pressure and volume waveforms and performing measurements at zero transmural pressure during arm elevation in 11 volunteers. Continuous non-invasive finger blood pressure was measured by applying the Finapres monitor and the finger volume pulses were recorded by the UT9201 physiograph by using the photoplethysmographic principle of registration. Estimation of the beat-to-beat finger arterial compliance is based on (i) the recorded volume and pressure wave amplitudes (Vpulse and Ppulse) and (ii) on the calculation of the slope of the pressure-volume relationship from the first derivatives dV/dt and dP/dt of the recorded volume and pressure pulses near the point of the maximum slope. The results of the study demonstrate that the applied two methods similarly (correlation coefficient r = 0.97) describe the changes of the beat-to-beat compliance during hand elevation test. At the same time the second estimate was 18% higher than the first one (P = 0.003).