Central aortic pressure is independently associated with diastolic function.

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.

Cardiac resynchronization therapy acutely improves diastolic function.

BACKGROUND: Invasive studies have shown that cardiac resynchronization therapy (CRT) acutely improves left ventricular (LV) systolic performance and lowers filling pressures in a majority of patients with medically-refractory severe heart failure. Measurements included LV volume, ejection fraction, PWD early (E-wave) and atrial (A-wave) velocities, diastolic filling time (DFT), and DTI early diastolic mitral annular velocity (Em) at the lateral and septal annulus; PWD mitral E-wave/Em and E/FP were calculated to estimate LV filling pressures. RESULTS: Immediately after CRT, LV volumes decreased and LVEF increased significantly. PWD mitral E-wave velocity decreased and E-wave duration and DFT increased significantly; mitral E/FP ratio also decreased significantly, consistent with a decrease in LV filling pressure. Patients with a pre-CRT mitral E/A ratio >1 (n = 20), demonstrated improvements in LV diastolic filling and lower filling pressures whereas those with an E/A ratio < or =1 (n = 21) did not show significant changes in diastolic indices. CONCLUSIONS: The acute effects of CRT include echocardiographic evidence of reduced LV volumes and increased LVEF with improved diastolic filling and lower filling pressures; LV relaxation is not significantly altered. The benefits in diastolic function are dependent on the PWD-determined LV filling characteristics prior to CRT.