Alternative criteria for the measurement of aortic valve with cardiac Doppler

pp 247-252

Abstract

The difficulties for the measurements of aortic valve area with cardiac Doppler are well known. Fifty seven patients with aortic stenosis were studied prospectively, with the aim of: 1) comparing alternative criteria like the acceleration time/ejection time in left ventricle outlet tract (≥ 0.52), the relation between left ventricle outlet tract velocity/maximal aortic valve velocity (≤0.25), maximal instantaneous gradient (≥  80 mmHg), mean gradient (≥ 50 mmHg) and fractional shortening/maximal instantaneous gradient (≤ 0.8) for determining the aortic stenosis severity; 2) assessing the utility inpatients with low cardiac output; 3) studying the influence of valvular associated lesions. Eleven patients had mild, 8 moderate and 38 severe aortic stenosis, evaluated through aortic valve area obtained with catheterism and/or Doppler. The acceleration time/ejection time in left ventricle outlet tract had a sensibility of 63% and specificity of 89 %,left ventricle outlet tract velocity/maximal aortic valve velocity 100 % and 89 %, respectively; maximal instantaneous gradient 68 and 100%; mean gradient 78 and 100%,and fractional shortening/maximal instantaneous gradient 100 and 89%, respectively. In the group of patients with low cardiac output, the severity was better determined with left ventricle outlet tract velocity/maximal aortic valve velocity and fractional shortening/maximal instantaneous gradient; of course the gradients were lower; so an inferior limit must betaken into account for defining the severity. The acceleration time/ejection time in left ventricle outlet tract relation had a poor sensibility. Nineteen patients had a catheterism; 17 with severe and two with mo-derate aortic stenosis, in agreement with Doppler hemodinamic data. It is concluded that the most useful criteria for defining severity are left ventricle outlet tract velocity/maximal aortic valve velocity and fractional shortening/maximal instantaneous gradient, even though in the population with low cardiac output. The presence of associated regurgitant valvulopathy impairs the utility of these parameters.