Chronic aortic regurgitation: the effect of aortic valve replacement on left ventricular volume, mass and function.

Serial echocardiographic left ventricular (LV) studies were performed in 19 patients before (preop) and after (postop) aortic valve replacement (AVR) for chronic aortic regurgitation (AR); the effect of AVR on LV volume, mass and function was determined from the echocardiographic data. In the 12 patients who were considered to have successful surgical results, the average LV end-diastolic dimension fell from a preop value of 6.9 +/- 0.2 cm to 5.5 +/- 0.2 cm (P less than 0.01) at the time of the early postop study (seven to 10 days). Muscle cross-sectional area (CSA) derived from dimension and wall thickness data was used as an index of LV muscle mass (preop CSA = 26 +/- 1.3 cm2); CSA was unchanged at the early postop study, but subsequently fell to near normal within six months after AVR (20 +/- 1 cm2, P less than 0.01). There was a trend toward improvement in systolic performance by the late postop studies (12+ months). In two out of three patients with postop paravalvular AR, LV dimension increased after an initial fall. Four patients without paravalvular AR failed to show a significant reduction in LV dimension in the postop studies. In this group the preop studies showed a tendency toward a large end-diastolic dimension and decreased fractional shortening, but the single preop parameter which differentiated these four from the successfully treated group was an end-diastolic radius-to-wall thickness (R/Th) ratio greater than or equal to 4. Thus, successful AVR for chronic AR results in the normalization of LV volume and a decrease in LV muscle mass to near normal. The R/Th ratio has important prognostic value which appears to be independent of fractional shortening in some patients with chronic AR.