Changes of the CO-diffusing components of the lung in patients with coronary artery disease (author's transl)

In 32 patients with angiographically proved CAD the diffusion parameters of the lung (intracapillary pulmonary blood volume, Vc, and diffusion capacity of the alveolo-capillary membrane, Dm, respectively the reciprocal value membrane resistance) were measured. As reference the pre-a-LVDP was used, as it represents more adequately than the LVEDP the pressure acting on the alveolo-capillary membrane. There was a significant positive correlation between the Vc and the pre-a-LVDP as well as a highly significant positive correlation between the diffusion resistance of the alveolo-capillary membrane and the pre-a-LVDP. This corresponds to a pulmonary congestion with an increase of Vc and an interstitial edema with an increase of the diffusion resistance of the alveolo-capillary membrane. The Dco may be unchanged in spite of a marked increase of LVDP, since the decrease of the membrane component is accompanied by an increase of the blood component of diffusion. Only the differentiation of the CO-transfer in its components Vc and Dm gives an information about changes of the hemodynamics in CAD.