Blood supply of the papillary muscles of the left ventricle of the dog´s heart (Canis familiaris L. 1758)

Abstract

The irrigation of the papillary muscles, has incomplete information on the distribution of the arterial vessels. Objectifying to establish the origin of these arteries and their distribution in the left ventricle papillary muscles, we used 30 hearts of adult, male and female mongrel dogs. After the death, the heart was removed, washed and injected through the left coronary artery opening with an acetate solution of stained vinyl, neoprene latex 650 colored or 10% gelatin. The papillary muscles in all the applied techniques had been fixed with 10% formaldehyde solution. The dissection was carried out with the aid of a 40% sulfuric acid solution. For accomplishment of the radiography, we used mercury injection what assisted the assembly of the studied vascularization projects. Clearing technique of Spalteholz was applied for better visualization of the cardiac irrigation. We evidenced that the subauricular and subatrial papillary muscles are irrigated by the left coronary artery branches. The subauricular papillary muscle was blood-supplied by the interventricular paraconal and circumflex branches and the subatrial papillary muscle mainly by the circumflex branch. The sub-segments that supply the subauricular papillary muscle from the interventricular paraconal branch are the left collateral and ventricular branches and from the circumflex branch: left dorsal branches and intermedial (left ventricular marginal) and rarely from the left ventricular ridge (diaphragmatic branch). The subsegments of the circumflex branch that supply the subatrial papillary muscle are: intermedial (left ventricular marginal), from the left ventricular ridge (diaphragmatic branch), right dorsal branches and subsinuous interventricular branch. In some cases we observed the collateral branch and the proper interventricular paraconal branch reaching the portion of the vertex of the subatrial papillary muscle.