RESUMO
Doppler echocardiographic and catheter measurements of pressure gradients were compared in 29 patients (61 +/- 11 a) with isolated aortic stenosis. In addition we retrospectively evaluated which easily obtained Doppler echocardiographic parameters might indicate severe aortic stenosis requiring surgery. Catheter-derived peak to peak and mean gradients correlated well with maximum systolic Doppler gradient (r = 0.78, p less than 0.01) and mean Doppler gradient (r = 0.73, p less than 0.01). Using the continuity equation, the aortic valve area was assessed in 14 patients by Doppler echocardiography. A good correlation was found with catheter-determined aortic valve area (r = 0.83, p less than 0.01). Surgical intervention was recommended in 19 patients after left heart catheterisation. Doppler determined maximum transvalvular flow velocity (Vmax.) was greater than 4.5 m/s in 10 patients, all ultimately considered to be surgical candidates. None of the 7 patients with Vmax. less than 3.8 m/s proved to have critical aortic stenosis. In 12 patients Vmax. was between 3.8 and 4.5 m/s. In this group aortic valve replacement was advised in 9 patients after catheterisation. In 5 surgical candidates echocardiography showed reduced left ventricular function (systolic shortening fraction less than 0.27). Hence, the Doppler derived peak flow velocity greater than 4.5 m/s or peak flow greater than 3.8 m/s in the presence of reduced left ventricular function indicate severe aortic stenosis requiring surgery.