Evaluation of left ventricular relaxation and estimation of filling pressures by tissue doppler imaging

ABSTRACT

Doppler Left ventricular [LV] filling indices have been used to evaluate different parameters of diastolic function. However the- interpretation of these indices becomes challenging when several haemodynamic alterations occur simultaneously. Color M-mode and Doppler tissue imaging [DTI] have been shown to provide an accurate estimation of LV relaxation and appear to he relatively insensitive to the effect of preload compensation. The aim of this study was to assess the value of DTI the evaluation of LV relaxation and in the estimation of LV filling pressure among patients with coronary artery disease [CAD].We studied 30 patients with CAD and 10 normal control volunteers [6 males and 4 females; age 35.50 +/- 7.32 yrs]. The patients included 15 [45.80 +/- 9.67 yrs] with impaired relaxation [IR] and 15 [55.73 +/- 7.82 yrs] with pseudonormal relaxation pattern. Alt patients were subjected to conventional Doppler echocardiography to assess LV diastolic function by measurement of E and A waves and time E/A ratio]. For DTI, the following mitral valve annular velocities were measured peak systolic velocity [Sa], early "Ea" and late "Aa" diastolic velocities, acceleration time of Ea [from onset to peak of Ea], deceleration time of' Ea [from peak to baseline] and the E/Ea [ratio of transmitral E to mitral annular E velocity]. LV catheterization was done to measure LV end-diastolic pressure [LVEDP] by fluid filled catheter. RV catheterization was done to measure pulmonary capillary wedge pressure [PCWP]. E/A ratio could not different between normal and groups. Both normal and pseudonormal groups displayed higher E wave 82.3 +/- 13.5 and 78.13 +/- 15.11, respectively and higher E/A ratio "1.3 +/- 0.12 and 1.9 +/- 0.3, respectively", compared to impaired relaxation group "E 55.60 +/- 7.08, E/A ratio=0.68 +/- 0.12", Sa was significantly reduced in the pseudonormal group compared to the other 2 groups. Early diastolic annular velocity [Ea] was significantly lower in pseudonormal and impaired relaxation groups [5, 33 +/- 1.7 and 7.37 +/- 2.01] compared to normal group [14.70 +/- 3.3] [P< 0.001]. E/Ea ratio was significantly increased in pseudonormal group compared to the other 2 groups. There was good correlation between E/Ea and PCWP [PCWP = 1.29 [E/Ea] + 1.9.] There was a good relation between E/Ea ratio and LVEDP. The difference between catheter and Doppler-measured LVEDP was 0.1 +/- 3.8. In normal group. PCWP was 9.27 +/- 1.9 by DTI, 8.0 +/- 2.3 by catheter. In impaired relaxation group, PCWP was 11.20 +/- 2.4 by DTI, 10.47 +/- 3.23 by catheter. In pseudonormal group. PCWP was 21.93 +/- 8.5 by DTI, 21.80 +/- 6.91 by catheter. Early diastolic velocity of the mitral annulus "Ea" can distinguish a pseudonormal mitral inflow pattern from a normal one. E/Ea is an accurate method for estimation of LV filling pressures