Estimation of aortic wave intensity using non-invasive pressure waveforms (pWIA) showed acceptable agreement with LVOT velocity-derived estimates and fair to good reproducibility.
Observational (n=46)
Can aortic wave intensity be accurately and reproducibly estimated using only non-invasive pressure waveforms compared to conventional pressure-flow measurements?
Non-invasive pressure-only wave intensity analysis is a feasible and reproducible surrogate for conventional pressure-flow methods, potentially enabling wider application of hemodynamic assessments in large studies.
Abstract Background Wave intensity analysis provides valuable information on ventriculo-arterial function, hemodynamics and energy transfer in the arterial circulation. Widespread use of wave intensity analysis is limited by the need for concurrent measurement of pressure and flow waveforms. We describe a method that can estimate wave intensity patterns using only non-invasive pressure waveforms (pWIA). Methods Radial artery pressure and left ventricular outflow tract (LVOT) flow velocity waveforms were recorded in 12 participants in the Southall and Brent Revisited (SABRE) study. Pressure waveforms were analysed using custom-written software to derive the excess pressure ( P xs ) which was scaled to peak LVOT velocity and used to calculate wave intensity. These data were compared with wave intensity calculated using the measured LVOT flow velocity waveform. In a separate study, repeat measures of pWIA were performed on 34 individuals who attended 2 clinic visits at an interval of approximately 1 month to assess reproducibility and reliability of the method. Results P xs waveforms were similar in shape to aortic flow velocity waveforms and the time of peak P xs and peak aortic velocity agreed closely. Wave intensity estimated using pWIA showed acceptable agreement with estimates using LVOT velocity tracings and estimates of wave intensity were similar to values reported previously in the literature. The method showed fair to good reproducibility for most parameters. Conclusions The P xs is a surrogate of LVOT flow velocity which, when appropriately scaled, allows estimation of aortic wave intensity with acceptable reproducibility. This may enable wider application of wave intensity analysis to large studies.
Hughes et al. (Fri,) reported a observational. Estimation of aortic wave intensity using non-invasive pressure waveforms (pWIA) vs. Wave intensity calculated using measured LVOT flow velocity waveform was evaluated on Agreement between pWIA and LVOT velocity-derived wave intensity, and reproducibility. Estimation of aortic wave intensity using non-invasive pressure waveforms (pWIA) showed acceptable agreement with LVOT velocity-derived estimates and fair to good reproducibility.