The reservoir pressure analysis was developed based on the presumption that aortic pressure is composed of a pressure contributed by aortic blood volume (reservoir pressure; Preservoir) and a pressure attributed to wave motions (excess pressure; Pexcess). Preservoir can be derived by measured aortic pressure and flow waveforms. Subsequently, reservoir pressure analysis based on pulse waveforms analysis alone (PWA) was developed based on the observation that Pexcess was proportional to aortic flow. In this validation study, we aimed to compare the Preservoir parameters derived from PWA with those from conventional pressure and flow waveforms analysis (PFA).Design and Method:
A total of 202 subjects with various cardiovascular diseases (57.7% men, mean age 57.3 ± 17.7 years) were included, in whom central pressure and flow waveforms were measured using carotid arterial tonometry and Doppler echocardiography, respectively. Preservoir analysis was conducted by both PWA and PFA models to derive 6 parameters, including peak of Preservoir (Pr_peak), amplitude of Preservoir (Pr_pulse), excess pressure integral (XSPI), reservoir pressure integral (PRI), systolic rate constant (SC), and diastolic rate constant (DC).Results:
The intra-class correlation coefficients of these parameters between the two methods ranged from 0.766 to 0.994 (Pr_peak = 0.99, Pr_ pulse = 0.98, XSPI = 0.92, PRI = 0.97, SC = 0.77,and DC = 0.86), and the bias (mean differences) and precision (standard deviation of differences) were -2.24 and 2.16 for Pr_peak, -2.49 and 2.05 for Pr_ pulse, 0.33 and 0.96 for XSPI, -0.39 and 1.11 for PRI, -2.35 and 7.95 for SC, and -0.13 and 0.55 for DC.Conclusions:
The PWA-derived Preservoir parameters agreed reasonably well with those calculated by the conventional PFA approach, and could serve as good surrogates for further hemodynamic interpretations and studies.