Does aortic regurgitation affect transmitral flow? An echo-Doppler study

Recent studies suggest that the presence of aortic regurgitation can interfere with Doppler measurement of mitral pressure half-time in patients with mitral stenosis. Amongst the factors affecting the transmitral flow in aortic regurgitation a putative role may be played by the mechanical hit of the aortic regurgitant jet impinging on the anterior mitral leaflet, as is very often seen with Doppler Color Flow examination. This study was designed to evaluate the effects of pure aortic regurgitation on the transmitral flow in patients with normal mitral valves. We studied 35 patients affected by pure chronic aortic regurgitation but with a normal mitral valve and compared them with 30 normal subjects. In all the patients the aortic regurgitant jet was directed toward the anterior mitral leaflet. In all the patients and control subjects a standard echo-Doppler examination was performed, sampling the transmitral flow at the level of the tip of the mitral leaflets. In 7 patients and 11 normal subjects the transmitral flow was also sampled at the level of the mitral annulus. Patients with aortic regurgitation showed significantly higher values of the mitral pressure half-time (61.04 +/- 15.14 vs 50.59 +/- 7.07 ms, P < 0.05) and of the time-velocity integral of the total transmitral flow, while the other parameters of transmitral flow, the mitral annulus diameter and the mitral stroke volume didn't show statistically significant differences. The comparison of the pressure half-time and time-velocity flow values measured at the level of the mitral annulus between patients and normal subjects didn't show significant differences.(ABSTRACT TRUNCATED AT 250 WORDS)