[Value of the continuous Doppler in the evaluation of gradients of aortic valvular stenosis in the adult]. / Valeur du Doppler continu dans l'évaluation des gradients des sténoses aortiques valvulaires de l'adulte.

ABSTRACT

The purpose of this study, performed in 80 patients with aortic valve stenosis, was to find out whether continuous wave doppler ultrasound was reliable in assessing the severity of the stenosis. Maximum mean and instantaneous transaortic pressure gradients obtained by continuous wave doppler were compared with maximum mean instantaneous and peak to peak gradients simultaneously obtained by cardiac catheterization. 35 patients who underwent aortic valve dilation were explored beforehand and afterwards, which brings up to 115 the total number of gradient comparisons. There was a correlation between maximum instantaneous gradient at doppler and peak to peak gradient (r = 0.62, n = 115, e = 22.5 mmHg, p less than 0.001). A similar correlation was found between maximum instantaneous gradients at doppler and haemodynamics (r = 0.64, n = 80, e = 24.5 mmHg), but correlation between mean gradients was weaker (r = 0.57, n = 80, e = 17.7 mmHg). Maximum and mean instantaneous gradients are underestimated by the doppler method. After exclusion of imperfect doppler curves, correlations were better, notably as regards mean gradients (r = 0.80, n = 18, e = 11.9 mmHg). There was a closer correlation between doppler maximum instantaneous gradients and haemodynamic peak to peak gradients in patients without aortic regurgitation (r = 0.71, n = 45, e = 17.2 mmHg) than in patients with aortic regurgitation (r = 0.54, n = 70, e = 24.3 mmHg).(ABSTRACT TRUNCATED AT 250 WORDS)