DETERMINATION OF AORTIC-VALVE ORIFICE AREA IN AORTIC-VALVE STENOSIS BY TWO-DIMENSIONAL TRANSESOPHAGEAL ECHOCARDIOGRAPHY

Two-dimensional transesophageal echocardiography was used to measure aortic valve orifice area in 24 patients with aortic valve stenosis (AS) and 15 patients without aortic valve disease. Using transesophageal echocardiography, orifice area could be measured in 20 of 24 patients with AS. With transthoracic echocardiography, orifice area could be determined in only 2 of 24 patients. In patients with AS, orifice area determined by transesophageal echocardiography was 0.75 .+-. 0.34 cm2 and that calculated with Gorlin''s formula was 0.75 .+-. 0.32 cm2. In normal aortic valves, orifice area was 3.9 .+-. 1.2 cm2 by transesophageal echocardiography. A good correlation was demonstrated between aortic valve orifice area determined using transesophageal echocardiography and calculated orifice area using Gorlin''s formula in patients with AS: r = 0.92, standard error estimate = 0.14 cm2. The absolute difference between orifice area measured with both methods ranged from 0.0 to 0.4 cm2 (mean 0.09 .+-. 0.1). In 4 patients orifice area could not be determined with transesophageal echocardiography. The orifice could not be identified in 2 patients because an appropriate cross-sectional view of the aortic valve could not be achieved and in 2 patients with pinhole stenosis (aortic valve orifice area 0.3 cm2). These data show that aortic valve orifice area can be measured reliably using 2-dimensional transesophageal echocardiography.