Evaluation of coronary dominance in pigs; a comparative study with findings in human hearts (Avaliação da dominância coronária em suínos. Estudo comparativo com os achados em corações humanos)

ABSTRACT Coronary dominance in swine has been poorly evaluated. The frequencies of each type of dominance have been described, but few details have been given as to the different expressions of each one. The aim of this study was to characterize coronary dominance in commercial breed swine. One hundred and fifty eight pig hearts were evaluated. The coronary arteries (CA) were infused with synthetic resin (Palatal 85% and Styrene15%) through the ostia after channeling. The coronary artery that gives origin to the posterior interventricular artery (PIA), and the site of termination of both the circumflex arteries (CXA), and left retroventricular branch (LRVB) were determined in order to establish the coronary dominance pattern. Right coronary dominance was found in 105 hearts (66.5%), and a balanced circulation in 53 specimens (33.5%). No dominance was observed for the left coronary artery in the hearts studied. The CXA ended on the posterior aspect of the left ventricle in 101 samples (64%) and on the crux cordis in 55 specimens (34.8%). In two specimens (1.3%) it ended as a left marginal artery. In all cases the PIA was a branch of the RCA, and was long in 105 hearts (66%), 55% of which corresponded to males and 45% to females, but this difference was not statistically significant (p=0.77). The AIA ended on the apex in 126 specimens (80%), 71 of which (56%) corresponded to males and 55 (44%) to females (p=0.74). Regarding right coronary dominance, subtype I was observed in 98 specimens (93.3%), subtype II in 5 cases (4.8%), whereas subtype III was observed in 2 hearts (1.9%). Knowing coronary dominance patterns and their irrigation territories is useful for training purposes based on the use of experimental and hemodynamic models with this animal species. Keywords: pig, coronary dominance, coronary arteries, left dominance, balanced circulation