Comprehensive analysis of effective reflection distance under diverse hemodynamic conditions

Abstract

Distance to a major reflection site, effective reflection distance (ERD), is associated with aging and augmentation index (AIx). However, it remains unclear whether and how ERD varies and associates with AIx when hemodynamics is acutely perturbed. In 13 anesthetized dogs, we measured arterial pressure, aortic flow, while altering the hemodynamic condition over wide ranges by administering a variety of cardiovascular drugs. Using measured data, we determined ERD based on an arterial model comprising a tube with Wind-Kessel (ERDtl), a physiologically valid model. We also determined ERD based on wave separation (ERDwsa) and pressure-based analyses (ERDaw). ERDtl was shortened significantly in response to vasodilator or inotrope administration, and was significantly and negatively associated with AIx in multiple regression analysis. ERDwsa or ERDaw did not necessarily correlate with ERDtl in terms of drug responses or association with AIx. Present results should be kept in mind in analysing ERD and AIx.