[Functional and true intrapulmonary shunts and their dynamics in acquired heart defects]

One hundred thirty nine patients with acquired valvular defects were examined, 56 of them were studied in dynamics as well as nine healthy subjects. The changes in the functional and true intrapulmonary shunts were studied as well as the alveolar-arterial gradients for O2 in breathing of atmospheric air and 100% O2, the slope of the alveolar plateau of capnogram, etc. The results obtained revealed a considerable reduction of the values of the functional and true intrapulmonary shunts, the alveolar-arterial gradients for O2 and the slope of the alveolar plateau of capnogram after the treatment carried out. In stage I of cardiac insufficiency the values obtained after the treatment are very close to the normal, suggesting the possibility of complete reversibility of the functional disorders established at the initial stage of cardiac insufficiency. The presence of a considerable increase of the shunts and the alveolar-arterial gradients for O2 even before the manifestation of the clinical signs enables the early functional diagnostics in parallel with the changes in diffusibility of lungs, described by us. The dynamic study of those functional studies reveals some of the pathogenetic mechanisms of the disorders in the respiratory system in case of acquired heart defects.