A new and simple method to measure maximal aortic valve pressure gradients by Doppler echocardiography

Most echocardiographic laboratories now use continuous-wave Doppler to measure transvalvular pressure gradients in patients with valvular aortic stenosis (AS). In many cases, particularly in the elderly, this technique can be difficult and time-consuming, and there is no immediate means of verifying the accuracy of the results. In the present study, a new and simple method is proposed to calculate maximal aortic valve gradients from the pulsed-wave Doppler tracing recorded in the left ventricular outflow tract. The method consists of calculating maximal aortic flow velocity and thus the maximal gradient by extrapolating to their point of intersection the initial accelerating velocity and the terminal decelerating velocity recorded on the pulsed Doppler tracing. In 20 patients with varying degrees of AS, there was an excellent correlation (r = 0.96, p less than 0.001) between the results obtained by this method and those obtained by continuous-wave Doppler. In 10 patients who had cardiac catheterization, the results also correlated well with the maximal gradient (r = 0.93, p less than 0.001) measured at cardiac catheterization. Because the method is simple, it should become an integral part of the Doppler examination in patients with AS. Its main advantages will be to serve as an independent confirmation of the results obtained by continuous-wave Doppler and to reduce in many patients the duration of the examination.