Remodeling of the bifurcation asymmetry of right coronary ventricular branches in hypertrophy.

To document the remodeling of the asymmetric branching pattern of the coronary right ventricular branches (RVBs) in right ventricular hypertrophy (RVH), we computed an asymmetry ratio, S, for the diameters and lengths of all vessels, defined as the ratio of the daughter diameters and lengths, respectively. We have previously induced RVH in pigs by pulmonary stenosis for five weeks. At autopsy, silicone elastomer casts of the right coronary arteries were made and the morphometric data on the branching pattern and vascular geometry of the RVB were collected. Data on smaller vessels were obtained from histological specimens while data on larger vessels were obtained from vascular casts. The results show that the diameter asymmetry ratio was significantly decreased in RVH hearts. The asymmetry ratios of diameters and lengths were used to compute the asymmetry ratios for vascular resistance and flow of the various daughter vessels. It was found that the degree of asymmetry of the resistance and flow were decreased, which implies that the flow heterogeneity at a bifurcation is decreased in the RVH hearts.