Studies on the renal circulation and renal function in mitral valvular disease. I. Effect of exercise

In 31 patients with mitral stenosis of varying severity the effect of light, steady exercise during 15 to 17 minutes on renal function and renal circulation has been studied during heart catheterization. The results have been compared with the values obtained at rest in 72 patients with mitral stenosis. Exercise produced a decrease in clearance of para-aminohippurate and sodium excretion and an increase in renal resistance, changes not produced in normal individuals. Cardiac output and pulmonary pressures increased. In patients with right heart failure exercise produced increased pressures but no increase in cardiac output, and only slight changes in clearance but increase in renal resistance and renal venous pressure.