Detection of "pathologic" prosthetic valve stenosis via exercise Doppler echocardiography

To detect borderline mitral valve dysfunction in asymptomatic patients, with Björk-Shiley valves, we studied the patients' hemodynamics at rest and during exercise by Doppler echocardiography. Supine bicycle exercise was performed by 65 patients. The patients were divided into two groups according to the measurements of the exercise Doppler echocardiography: a normally functioning group (n = 45) and a borderline group (n = 20). The valve area at rest was 2.0 +/- 0.6, 2.1 +/- 0.7, and 2.3 +/- 0.5 cm2 with valve sizes of 25, 27, and 29 mm, respectively, in the normal group and 1.9 +/- 0.5, 1.9 +/- 0.4, and 2.1 +/- 0.3 cm2 in the borderline group. The mitral valve area did not significantly change with exercise in either group. In the normal group, peak gradients increased from 9.9 +/- 3.5, 9.7 +/- 1.1, and 9.5 +/- 1.6 mmHg with valve sizes of 25, 27, and 29 mm, respectively, at rest to 15.1 +/- 3.1, 14.0 +/- 3.3, and 14.8 +/- 2.6 mmHg with exercise. Mean gradients increased from 5.2 +/- 1.2, 5.9 +/- 1.3, and 5.8 +/- 1.8 mmHg with valve sizes of 25, 27, and 29 mm, respectively, at rest to 8.0 +/- 2.5, 9.1 +/- 2.0, and 8.8 +/- 1.6 mmHg with exercise. In the borderline group, peak gradients increased from 10.5 +/- 3.1, 10.1 +/- 2.1, and 10.8 +/- 1.7 mmHg with valve sizes of 25, 27, and 29 mm, respectively, at rest to 24.5 +/- 4.2, 23.6 +/- 4.4, and 22.4 +/- 3.2 mmHg with exercise.(ABSTRACT TRUNCATED AT 250 WORDS)