Postoperative changes in diastolic function of the left ventricle in patients with aortic valve stenosis

Abstract

Diastolic dysfunction in valvular aortic stenosis frequently precedes systolic dysfunction. The purpose of this study was to examine the changes in left ventricular diastolic function after aortic valve replacement. Seventy eight patients with significant isolated valvular aortic stenosis were enrolled in the study. The echocardiographic examination was performed with ACUSON-XP 10 imaging system. Complete M-mode, 2-dimensional and Doppler echocardiographic results were obtained. In 48 patients right and left heart catheterisation was performed. Left ventricular diastolic function was evaluated by pulse Doppler recording of inflow velocity on the tips of the mitral valve leaflets. Forty two underwent aortic valve replacement. They were followed up 6-12 months postoperatively. Abnormal patterns of left ventricular diastolic filling were noticed in almost all patients (Table 1). Most prominent changes were found in subjects with marked and diffuse hypertrophy (Table 2). After aortic valve replacement decrease in left ventricular size, mass, pressures and improvement in systolic Function (Table 3). Twelve months after the operation late diastolic filling velocity was lower (A = 64 +/- 15 cm/s, Avti = 7.1 +/- 1.8 cm), early diastolic filling velocity was higher (E = 83 +/- 14 cm/s, Evti = 10.3 +/- 1.4 cm), deceleration time (DT = 123 +/- 14 ms) and isovolumetric relaxation time (IRT = 66 +/- 6 ms) were longer in patients with preoperative moderate hypertrophy (Table 4). In patients with severe left ventricular hypertrophy changes in diastolic function were slower. We found decrease in early diastolic filling velocity (A = 44 +/- 6 cm/s, Avti = 4.6 +/- 04 cm), increase in late diastolic filling velocity (E = 67 +/- 14 cm/s, Evti = 9.4 +/- 1.7 cm), with prolongation of deceleration (DT = 131 +/- 18 ms) and isovolumetric relaxation time (IRT = 94 +/- 23 ms) (Table 5). In adults with significant sympthomatic aortic valve stenosis, aortic valve replacement is therapy of choice. Replacement of the diseased aortic valve with a prosthetic valve yields relief of left ventricular outflow obstruction. Myocardial remodeling with regression of mass transpires as the heart adapts to the new level of afterload. In patients with moderate left ventricular hypertrophy improvement in diastolic function during the first year after aortic valve replacement is visible, while in patients with extreme myocardial hypertrophic changes it was slower.