Capillary density and oxygen supply in human dilated cardiomyopathy.

Human hearts with dilated cardiomyopathy (DCM) exhibit a hypertrophy of the myocytes; consequently, the intercapillary distance increases, which may impede the diffusionable metabolic supply. Therefore in the following study the microcirculation of living human hearts with DCM, excised during cardiac transplantation, was investigated. The hearts were reperfused with a FITC-stained salt-solution, this allowed the precise detection of all plasma perfused capillaries. Thus, functional capillary density, capillary distribution and its effect on oxygen supply could be determined. In eight human hearts, the average functional capillary density amounted to 1245 +/- 345 capillaries/mm2, while 50% of the tissue was within 12 micron from the nearest capillary. However, a small portion of the tissue (1%) might become anoxic under the assumption of a simple oxygen diffusion model. The results favor the view that capillary density is low in human DCM and tissue is at the border of hypoxia.