[Determination of the transaortic valve gradient in aortic stenosis by continuous Doppler echocardiography].

A correlative study was carried out between the transvalvular aortic gradient determined by continuous wave Doppler echocardiography and by cardiac catheterization (retrograde or transseptal) in 41 patients with proved by invasive methods aortic valvular stenosis of different degree with or without accompanying aortic incompetence (light, moderate or severe). A considerable correlation was found between the transvalvular aortic gradient determined by the two methods (r = 0.75). In spite of that in considerable number of cases there is overestimation or underestimation of the transvalvular aortic gradient determined by Doppler echocardiography compared with the one determined by cardiac catheterization. The overestimation of the transvalvular aortic gradient determined by Doppler echocardiography is due to the accompanying aortic incompetence of greater degree and to the condition that the gradient determined by Doppler echocardiography is maximum instantaneous while the one determined by cardiac catheterization is peak to peak and is principally of lower values. The underestimation of the transvalvular aortic gradient is due to the presence of considerable left ventricular dysfunction and technical faults in the Doppler echocardiographic examination.