Central aortic pressure is independently associated with diastolic function

Abstract

Background: Studies investigating the association between central aortic pressures and diastolic function have been limited.

Methods: Consecutive ambulatory patients (n = 281, mean age 49 +/- 13 years, 49% male) with normal left ventricular (LV) systolic function were included. The LV filling pressure (E/Em) was estimated by Doppler-derived ratio of mitral inflow velocity (E) to septal (Em) by tissue Doppler, LV relaxation by Em, and central aortic pressures by radial tonometry. Central aortic systolic (cSBP), diastolic (cDBP), mean (cMAP) and pulse pressure (cPP) were entered individually into stepwise linear regression models to determine their association with E/Em or Em.

Results: In univariate analysis, cPP correlated most strongly with E/Em (Spearman's rho = 0.45, P < .001), whereas cSBP correlated most strongly with Em (Spearman's rho = -0.51, P < .001). Multivariate analysis demonstrated that the pulsatile component of afterload, cPP, contributed most to E/Em (partial r(2) = 23%); meanwhile, the nonpulsatile components (cDBP and cMAP) were significant but small contributors (partial r(2) of 6% and 5%, respectively) of LV relaxation (Em).

Conclusion: The nonpulsatile components of aortic afterload (cMAP and cDBP) exhibited a weak but significant association with LV relaxation, whereas the pulsatile component of afterload, cPP, exhibited strong association with LV filling pressure.

Figure 1

Working Model of the Pulsatile and Nonpulsatile Components of Central Aortic Blood Pressure. **Pulsatile elements, ++ Nonpulsatile elements.

Figure 2

Components of the Central Aortic Pressure Waveform. cAP=Central Augmented Pressure, NRPP=Non-reflected Pulse Pressure, cPP=Central Aortic Pulse Pressure.