Evaluation of St. Jude Medical Mitral Valve Function by Exercise Doppler Echocardiography

ABSTRACT The aim of this study was to detect borderline mitral valve dysfunction in 100 asymptomatic patients with a St. Jude Medical valve. We studied rest and exercise hemodynamics by Doppler echocardiography. Study patients were divided into two groups according to the time since surgery: group A had valves implanted less than 5 years ago (44 patients), group B had valves implanted more than 5 years ago (56 patients). Although patients had no clinical signs of valve dysfunction, group B was found to have significant reduction of mitral valve area (p < 0.05). In the group A patients, mean gradients at rest increased from 4 ± 2, 4 ± 2, and 3 ± 1 mmHg in valve sizes of 25, 27, and 29 mm, respectively, to 7 ± 2, 7 ± 3, and 5 ± 2 mmHg with exercise. In the group B patients, mean gradients at rest increased from 7 ± 1, 6 ± 2, and 5 ± 1 mmHg to 14 ± 3, 13 ± 3, and 10 ± 4 mmHg, respectively, after exercise. The percent increase (mean) in peak pressure gradient with exercise was significantly higher in group B (more than 100%) than in group A (less than 80%) (p < 0.01). The percent increase in mean gradient with exercise was also significantly higher in group B (more than 100%) than in group A (less than 75%). In conclusion, patients with reduced valve area and more than a 100% increase of peak and mean gradients should be followed up carefully. If any signs or symptoms of heart failure develop, they must be considered as candidates for surgery. 1995 Futura Publishing Company, Inc.