Important pressure recovery in patients with aortic stenosis and high Doppler gradients

Pressure recovery has been described in aortic stenosis and may explain the difference occasionally observed between Doppler- and catheter-measured gr adients. A narrow ascending aorta (AA) and moderately severe stenosis favor s pressure recovery. The aims of this study were to investigate the degree to which these conditions are present in patients with aortic stenosis and high Doppler gradients and to evaluate the magnitude of pressure recovery. One hundred sixteen patients were examined with Doppler echocardiography be fore aortic valve replacement. Patients with a maximum gradient > 70 mm Hg (n = 81) were included. The diameter of the AA was measured and compared wi th the diameter in an age- and body sire-matched group of normal controls ( n = 23), Pressure recovery was estimated from a previously validated equati on by measuring the maximum Doppler gradient, the effective orifice area (E OA), and the diameter of the AA, The diameter of the AA was similar for pat ients (mean 3.0 cm, range 2.1 to 4.1) and normal controls (mean 3.0 cm, ran ge 2.3 to 3.5). The maximum Doppler gradient was 107 mm Hg (range 71 to 170 ) and the EOA was 0.6 cm(2) (range 0.2 to 1.3), The calculated pressure rec overy was 18 mm Hg (range 6 to 37), which gives a net gradient of 89 mm Hg (range 51 to 151), Twenty-three percent had a net gradient < 70 mm Hg. A cu toff of EOA/AA diameter at >0.2 cm identified 84% of patients (16 of 19) wi th a net gradient < 70 mm Hg. In conclusion, we found that important pressu re recovery con be expected in most patients with aortic stenosis and high Doppler gradients. Pressure recovery may explain why some patients with hig h Doppler gradients ore asymptomatic. Also, pressure recovery is a factor t o consider in patients with atypical symptomatology and high Doppler gradie nts when one must decide on valvular replacement. (C) 2001 by Excerpta Medi co, Inc.