Early and late changes in left ventricular systolic performance after percutaneous aortic balloon valvuloplasty

Abstract

To evaluate early and late hemodynamics after aortic valvuloplasty, 17 patients underwent first-pass radionuclide angiocardiography with simultaneous high-fidelity micromanonteter pressure before, 10 minutes after and 6 months after aortic valvuloplasty. Pressure-volume and stress data were assessed. Immediately after the procedure, no significant change was observed in heart rate, systemic blood pressure, cardiac output or aortic insufficiency (as measured by visual or quantitative aortography). The mean and peak transvalvular gradient decreased from 64 to 36 mm Hg (p < 0.001) and 76 to 38 mm Hg (p < 0.001), respectively. The mean aortic valve area increased from 0.5 to 0.8 cm 2 (p < 0.001). Using echocardiography, meridional end-systolic wall stress decreased from 81 to 63 · 10 3 dynes/cm 2 (p < 0.001). Left ventricular ejection fraction increased from 0.48 to 0.54 (p < 0.01), end-diastolic volume decreased from 161 to 143 ml (p < 0.001) and end-diastolic pressure decreased from 18 to 13 mm Hg (p < 0.01). Left ventricular stroke work (the area of the pressure-volume loop) also decreased from 17.5 to 14.7 · 10 6 ergs (p < 0.001). The loop shifted to the left and downward. At the 6-month study, the mean and peak aortic valve gradient increased from 36 to 56 mm Hg (p < 0.001) and 38 to 61 mm Hg (p < 0.001), respectively. The aortic valve area worsened (0.8 to 0.5 cm 2, p < 0.001), end-systolic wall stress increased (63 to 84 · 10 3 dynes/cm 2, p < 0.001) and the left ventricular ejection fraction decreased (0.54 to 0.49, p < 0.02). The end-diastolic volume increased (143 to 159 ml) along with the end-diastolic pressure (13 to 21 mm Hg, p < 0.01). Left ventricular stroke work (14.7 to 16.3 · 10 6 ergs) was not different from baseline. The loop returned toward baseline. The changes seen in ejection fraction, however, were primarily related to changes in loading conditions. At 6 months, restenosis occurred in most patients, but was not always accompanied by a worsening of clinical status. The pressure-volume loop shifted back toward baseline and the ejection fraction decreased as end-systolic stress increased. There were little data to support an intrinsic change in myocardial contractile performance at any postprocedural interval after aortic valvuloplasty. Rather, the changes in ejection dynamics appeared primarily to be a function of altered loading conditions.