Value of isometric exercise testing during cardiac catheterization in mitral stenosis.

To examine the value of preoperative isometric exercise testing during cardiac catheterization in patients with mitral stenosis, the isometric handgrip exercise test was performed on 28 patients during preoperative diagnostic catheterization. Eighteen patients who subsequently underwent mitral valve surgery were recatheterized and reevaluated clinically 12 months after operation. Preoperatively, the patients were divided into 2 groups: 16 whose mean mitral valve pressure gradient increased greater than 4 mm Hg during isometric exercise (group A) and 12 whose pressure gradient decreased or increased less than 4 mm Hg (group B). The ejection fraction remained unchanged and the peak systolic pressure/end-systolic volume ratio increased during isometric exercise in group A (p less than 0.001). In group B, the ejection fraction decreased (p less than 0.001) and the peak systolic pressure/end-systolic volume ratio remained unchanged. In the total group, a positive correlation existed between the change in mean mitral valve pressure gradient during isometric exercise and the changes in measures of left ventricular function during exercise. The patients in group A had a significant improvement in both symptoms and in exercise tolerance as determined by symptom-limited bicycle ergometry after surgery. The patients in group B showed minimal or no symptomatic improvement and their exercise tolerance did not improve. The change in mitral valve pressure gradient during isometric exercise appears to reflect the left ventricular response to exercise.