PROGRESSIVE ENLARGEMENT OF THE REGURGITANT ORIFICE IN PATIENTS WITH CHRONIC AORTIC REGURGITATION

The severity of aortic regurgitation is dependent on the size of the r egurgitant orifice, the left ventricular response to volume overload, and the diastolic pressure difference across the aortic valve. The pur pose of this study was to test the hypothesis that the aortic regurgit ant orifice increases over time in patients with audible chronic aorti c regurgitation. To assess serial changes in aortic regurgitant severi ty by the use of two-dimensional and Doppler echocardiography, 59 pati ents (29 men and 30 women) with audible chronic aortic regurgitation w ere prospectively identified and evaluated annually with two-dimension al and Doppler echocardiograms. Patients were followed for a median of 38 months. We measured two separate indicators of the size of the reg urgitant orifice: the color Doppler regurgitant jet width and the Dopp ler-derived regurgitant orifice area. Jet width increased with time (0 .5 +/- 0.4 cm at baseline, 0.04 +/- 0.01 cm/year slope, p < 0.001). Th e regurgitant orifice area also increased (0.12 +/- 0.14 cm(2) at base line, 0.01 +/- 0.01 cm/year, p = 0.05). Changes in regurgitant orifice area were related to changes in left ventricular end-diastolic dimens ion (p < 0.001). There were no significant changes in left ventricular chamber dimensions, volumes, and regurgitant volume over time in this cohort. Increases in jet width and orifice area occurred in patients with all degrees of baseline disease severity, with bicuspid or tricus pid leaflet morphology, and with male or female sex. In this prospecti ve study of chronic aortic regurgitation, both jet width and Doppler-d erived regurgitant orifice area increased over time. These findings su ggest that one factor in the progression of chronic aortic regurgitati on is enlargement of the orifice.