Cardiovascular responses to isometric exercise in patients with mitral stenosis. Comparison with normal subjects and patients with depressed ejection fraction.

The hemodynamic response to isometric handgrip was evaluated in 15 patients with mitral stenosis (MS), 12 normal subjects, and 13 patients with severe left ventricular failure (LVF). Acceleration of heart rate and rise in left ventricular systolic pressure were not significantly different between the three groups. Left ventricular end-diastolic pressure did not change in normal subjects and patients with MS during handgrip, but it was raised markedly in patients with LVF. Cardiac index increased in normal subjects but did not change in patients with MS and LVF. Stroke index declined in patients with LVF. In all groups there was a modest and similar increase in oxygen consumption and significant widening of the arteriovenous oxygen difference in patients with LVF. In patients with MS, pulmonary capillary pressure increased by an average of 10.6 mm Hg, with a parallel rise in mean pulmonary vascular resistance. It is concluded that patients with MS demonstrate a normal chronotropic and pressor response to isometric exercise. Normal left ventricular end-diastolic pressure response to isometric handgrip stress in patients with MS suggests good left ventricular performance.