ANOVA followed by Tukey test, ‘F’ significant vs. Fistula, ‘S’ significant vs. Sham, n= 4–5 animals per group. A, representative ×10 micrographs of capillaries and cardiomyocyte membranes in POH and VOH. B, capillary density per area is reduced in advanced POH (POH-DCM) while it is preserved in compensated POH and intact in VOH; P= 0.003 for ANOVA. C, the number of capillaries per cardiac myocyte increases in both VOH and compensated POH (POH-CLVH) and regresses to control levels in the advanced POH (POH-DCM); P= 0.0014 for ANOVA.