Impact of arterial load and loading sequence on left ventricular tissue velocities in XXXX .

@entity1 @entity712 @entity455 @entity101 @entity122
OBJECTIVES: The aim of this study was to examine the relationship between individual components of left ventricular (LV) afterload and tissue Doppler echocardiography (TDE) velocities in @entity1 . BACKGROUND: Acute increases in afterload slow diastolic relaxation as assessed invasively, yet little is known about chronic effects of load and loading sequence on LV TDE velocities. METHODS: Forty-eight subjects underwent echo Doppler and color-coded TDE with comprehensive noninvasive vascular assessment. Arterial afterload was measured by effective arterial elastance (Ea) and systemic vascular resistance index (SVRI), and loading sequence was quantified by early- (carotid characteristic impedance [Zc]) and late-systolic loads (augmentation index [cAI]; late pressure-time integral [PTI3]). @entity455 was measured by carotid-femoral pulse wave velocity ( @entity122 ) and total arterial compliance. RESULTS: Early-diastolic velocity (E') varied inversely with Zc, SVRI, Ea, and @entity122 (r = -0.4 to 0.5; beta = 1.0 to 1.2; p < or = 0.004), but late-systolic load (cAI and PTI3 r = -0.6; beta = 1.6; both p < 0.0001) and arterial compliance (r = 0.6; beta = 1.4; p < 0.0001) had the strongest associations with E'. Load dependence was not altered by the presence of @entity101 , and in multivariate analysis only cAI and Zc significantly predicted E', even after adjusting for age (p < 0.05). Peak systolic velocity was additionally found to be inversely related to afterload, whereas other measures of contractility were not. CONCLUSIONS: Diastolic and systolic tissue velocities vary inversely with arterial afterload, with late-systolic load having the greatest influence on E'. These findings may partly explain the decrease in early relaxation velocity noted with aging, @entity101 , and @entity1 with @entity712 . Strategies to reduce afterload, vascular stiffening, and wave reflections may prove useful to enhance early diastolic relaxation.
