[Functional changes in the respiratory system in acquired heart defects]

A total of 52 patients were examined, 8 out of them healthy and 44 patients with acquired valves defects without accompanying pulmonary and other diseases. The indices of external respiration, alveolar-arterial gradients for O2 and CO2 were followed up as well as diffusion capacity of lungs and its components, acid-alkaline balance, functional and real shunts in the pulmonary circulation, etc. The summed up results revealed that considerable disturbances in external respiration, leading mainly to a restrictive ventilatory syndrome, developed with the lesion of myocardium and valve apparatus of the heart. The values of diffusion lung capacity for CO and its components--Dm and Vc are decreased. O2 and CO2 metabolism was disturbed. The results pointed to a moderately manifested hypoxemia, marked elevation of alveolar-arterial gradients for O2 and presence of respiratory alkalosis. A considerable increase in the functional and real shunts of the lungs were established, manifestations of the disturbed pulmonary ventilation and hemodynamics in the pulmonary circulation.