P55 Effects of Carotid Pressure Waveform Obtained in Different Ways on the Results of Wave Separation, Wave Intensity and Reservoir Pressure Analysis

Abstract

Purpose/Background/Objectives

Recently great attention has been placed on innovative cardiovascular biomarkers obtained from wave separation (WS), wave intensity analysis (WIA) and the reservoir-wave (RW) concept. Pressure waveforms needed to implement these techniques can be obtained in different ways. Aim of this study was to evaluate differences in WS, WIA and RW parameters obtained deriving pressure curves in different ways.

Methods

Twenty-two individuals (49 ± 17 years, 59% males) were examined. Common carotid blood flow waveforms were obtained from Pulsed-Wave Doppler images. Carotid pressure waveforms were obtained in four different ways: 1) standard method, i.e., with applanation tonometry; 2) linear scaling from ultrasound (US)-derived diameter curve; 3) exponential scaling from US-derived diameter curve; 4) linear scaling from an accelero-metric-derived diameter signal. In each case, reflection magnitude (RM) and reflection index (RI) were obtained from WS. The amplitude of the first positive peak (W1), of the second positive peak (W2) and of the negative one (Wb) were calculated from WIA; the maximum of the reservoir (maxPr) and the excess (maxPex) pressure were achieved from RW.

Results

According to the intra-class coefficient values, the agreement between the standard method and all the others was excellent in case of RM, RI, maxPrand maxPex(0.82–0.97), while reached only a fair/good level in case of W1, W2and Wb(0.44–0.82).

Conclusions

The use of alternative carotid pressure waveforms does not influence the cardiovascular parameters obtained by WS and RW, while those derived by WIA are affected by the carotid pressure curve employed.