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

Abstract

CHRONIC AORTIC REGURGITATION/Gaasch et al. with the technical assistance ofL. M. Woodbury SUMMARY 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 < 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 < 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-towall thickness (R/Th) ratio _ 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.OPTIMUM TIMING of valve replacement in patients with chronic left ventricular (LV) volume overload is a difficult and challenging problem. While aortic valve replacement often results in striking

Time course of regression of left ventricular hypertrophy after aortic valve replacement.

“…All prosthetic aortic valves are relatively stenotic2 13 compared with the normal aortic valve, and as such constitute an obligatory chronic afterload excess on the myocardium. This is particularly so in those patients with prior aortic stenosis in whom, because of the narrower aortic root, only smaller valve sizes could be inserted, and in whom a larger resting transprosthetic-valvular gradient 8 found in an echocardiographic study that improvement of the volumetric or dimensional abnormalities could be seen as early as 7 to 10 days after successful surgery, and that late systolic function may be better than preoperative function as myocardial regression proceeds. Observing that early (6 to 12 months) after aortic valve replacement for aortic insufficiency there were two groups of patients, those with substantial reductions in left ventricular chamber diameter and muscle cross-sectional area and those without, and that it was in the latter that the only two postoperative deaths occurred, they concluded that this constituted a "poor outcome" group.…”

2008 Focused Update Incorporated Into the ACC/AHA 2006 Guidelines for the Management of Patients With Valvular Heart Disease

“…[235][236][237][238][239][240][241][242][243][244][245][246] With time, during which the ventricle develops progressive chamber enlargement and a more spherical geometry, depressed myocardial contractility predominates over excessive loading as the cause of progressive systolic dysfunction. This can progress to the extent that the full benefit of surgical correction of the regurgitant lesion, in terms of recovery of LV function and improved survival, can no longer be achieved.…”

“…244,[247][248][249][250][251][252][253][254][255][256] A large number of studies have identified LV systolic function and end-systolic size as the most important determinants of survival and postoperative LV function in patients undergoing AVR for chronic AR. 235, Studies of predictors of surgical outcome are listed in Table 13.…”

Survival and functional results after valve replacement for aortic regurgitation from 1976 to 1983: impact of preoperative left ventricular function.

“…During the course of the current study, our strategy for patient management in aortic regurgitation was changed because of data implicating left ventricular function and severity of symptoms as important determinants of postoperative prognosis. '-8, 13,17,20,[30][31][32][33][34][35] Hence, many patients with left ventricular dysfunction in the current study underwent operation before the development of severe symptoms or impaired exercise capacity. Fifty-four of the 80 patients (68%) were able to complete stage I of our treadmill protocol, including 33 of 50 (67%) with subnormal ejection fractions.…”