[The influence of pulmonary 'venous' compliance on the static pulmonary compliance: a study of patients with left-sided heart disease with normal respiratory function]

In heart diseases, such as mitral stenosis and angina pectoris, the static pulmonary compliance has been reported to be decreased. By definition, the pulmonary "venous" system consists of the pulmonary veins and the left atrium. It plays an important role as the reservoir for the left ventricle. In this laboratory, the pulmonary "venous" compliance (Cp"v") has been evaluated as delta V/delta P of a short segment of the P"V" volume-pressure curve. To evaluate the influence of Cp"v" on the static pulmonary compliance and to speculate about the mechanisms of the reduction in static pulmonary compliance in left-sided heart disease, hemodynamic data and static pulmonary compliance (Cst) were measured in 27 patients with left-sided heart disease. Cst was measured with esophageal balloon technique in a sitting position. The static volume-pressure curve was fitted by a sigmoid model: V = Vm/(1 + e(A-P)/kappa), where kappa is a shape constant and an index of the lung stiffness. The pulmonary blood volume (PBV) was estimated with our own method, using radionuclide (RN) angiocardiography. The mean pulmonary artery wedge pressures (PAW) were measured using a floating catheter. Cp"v" was calculated as the delta V/delta P from the increment of pulmonary "venous" volume (delta V) and that of PAW (delta P) that occurred during passive elevation of the legs. Pulmonary arterial compliance (Cpa) was obtained from an analysis of the diastolic decline in pulmonary arterial pressure wave forms.(ABSTRACT TRUNCATED AT 250 WORDS)