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 < 0.001) and the mean gradient from 61 to 30 mm Hg (p < 0.001); aortic valve area increased from 0.55 to 0.80 cm2 (p < 0.001). Meridional end-systolic wall stress decreased from 83 to 55 × 103 dynes/cm2 (p < 0.01). LV ejection fraction increased from 0.41 to 0.48 (p < 0.01). LV end-diastolic volume decreased from 186 to 160 ml (p < 0.001), end-systolic volume decreased from 115 to 87 ml (p < 0.001) and end-diastolic pressure decreased from 22 to 17 mm Hg (p < 0.01). LV stroke work decreased from 16.0 to 14.0 × 106 erg (p < 0.001). No change was observed in peak positive LV soldP 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.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine