Changes in left ventricular systolic performance immediately after percutaneous aortic balloon valvuloplasty.

To evaluate the acute changes in left ventricular (LV) performance before and immediately after percutaneous aortic valvuloplasty, 25 patients underwent first-pass radionuclide angiocardiography for construction of pressure-volume loops. Simultaneously, high-fidelity micromanometric aortic and LV pressures were recorded. Echocardiographic wall thickness was used to define wall stress. After valvuloplasty, no acute changes were observed in the heart rate, aortic systolic pressure, cardiac output or degree of aortic insufficiency. Valvuloplasty decreased the peak aortic valve gradient from 73 to 40 mm Hg (p less than 0.001) and the mean gradient from 61 to 30 mm Hg (p less than 0.001); aortic valve area increased from 0.55 to 0.80 cm2 (p less than 0.001). Meridional end-systolic wall stress decreased from 83 to 55 X 10(3) dynes/cm2 (p less than 0.01). LV ejection fraction increased from 0.41 to 0.48 (p less than 0.01). LV end-diastolic volume decreased from 186 to 160 ml (p less than 0.001), end-systolic volume decreased from 115 to 87 ml (p less than 0.001) and end-diastolic pressure decreased from 22 to 17 mm Hg (p less than 0.01). LV stroke work decreased from 16.0 to 14.0 X 10(6) erg (p less than 0.001). No change was observed in peak positive LV dP/dt or the end-systolic pressure-volume ratio. This study documents variable and complex changes in the measures of cardiac function after aortic valvuloplasty. A decrease in the amount of LV outflow obstruction with maintenance of the cardiac output at a decreased level of LV filling occurs.