The effects of work on the pulmonary circulation in mitral stenosis.

In an attempt to understand more fully the hemodynamic effects in mitral stenosis, the vascular response to effort was studied in 12 cases. It was found that pulmonary arterial pressures rose, but did not necessarily parallel changes in the pulmonary "capillary venous" pressure (pcv), suggesting that the response pattern may be modified by secondary pulmonary vascular change. Further, in some studies, pulmonary "capillary venous" pressures were found to rise initially and then fall despite continuing work, emphasizing the necessity to choose work of such a degree and duration that a steady state may be obtained.