Lung Volumes and Alveolorespiratory Function in Mitral Stenosis

ABSTRACT

Lung Volumes and alveolorespiratory function were studied in 30 cases of pure or predominat mitral stenosis in slightly to moderately compromized state, and the results were compared with those in the normal controls. In patients with mitral stenosis, there was a singnificant reduction in the vital capcity and the total lung capacity, whereas the residual volume and its ratio to the total lung capacity were significantly increased. The distribution of inspired gas was uneven as reflected by increase in the lung clearnace index and in the slope of phase III of the single breath nitrogen washout curve. The alvelolar arterial oxygen tension gradient and the physiological dead space were singinificantly increased despite a singinificant decrease in the arterial carbon dioxide tension. The diffusing capacity was also reduced in some cases.