P2.23 the Reservoir Pressure Concept: The 3-Element Windkessel Model Revisited? Application to the Asklepios Population Study

Background Traditionally the arterial system is either modelled as a lumped-parameter windkessel model, or as a wave system. Recently, a hybrid model has been proposed in which the arterial system is considered to be a reservoir while still allowing for superimposed wave phenomena. We applied this novel approach to non-invasively obtained carotid pressure waveforms from 2024 subjects from the Asklepios population to investigate the contribution of reservoir pressure to pulse pressure with age and gender and compared it to the windkessel pressure obtained from a more traditional 3 element windkessel model approach. Methods PPres,WK and PPres,hybrid were determined by applying a 3-element windkessel model and the hybrid reservoir pressure concept to scaled carotid artery tonometry readings, respectively. The evolution of PPcar, PPres,WK and PPres,hybrid was separately examined for men and women after stratification of the population into age quartiles. Results Discussion PPcar increased with age regardless of sex, but was more pronounced in women. This increase is largely due to reservoir pressure, regardless of the model used. Hybrid model results closely resemble those obtained by a 3 element windkessel model, with a strong correlation (r=**, P<0.001) between PPres,WK and PPres,hybrid.