Relação dos músculos papilares com os segmentos anátomo-cirúrgicos do ventrículo esquerdo e ramos marginais da artéria coronária esquerda em cães (Canis familiaris, Linnaeus, 1758)

Abstract

In 20 hearts of mongrel dogs, the morphology and the relation of the papillary muscles of the left ventricule with the anatomic-surgical segments and marginal branches of the left coronary artery on the external surface of the left ventricule were studied. The objective was to provide ways of localizing them through the external surface of the left ventricule in order to avoid its inclusion in the plicated or sectioned muscular segment. After being washed, the hearts were fixed and preserved in formaldehyde solution 10%. Using needles, each papillary muscle was separated transversally into three portions: dorsal, median and ventral. The circumflex artery had left caudal-lateral ventricular (LCLV), intermediate (I) and right caudal-lateral ventricular (RCLV) marginal branches. The subauricular and subatrial papillary muscles are found in the left ventricule. In all the preparations, the subauricular papillary muscle was related to the left ventral anatomic-surgical segment (III); the subatrial papillary muscle was related to the right ventral anatomic-surgical segment (V) in 13 cases (65.0%), to the left marginal anatomic-surgical segment (IV) in 3 pieces (15.0%), and to both IV and V segments in 4 cases (20.0%). In 20 preparations (100%), the subauricular papillary muscle was related to the LCLV branch, and the subatrial papillary muscle to I and RCLV branches in 18 pieces (90.0%). The papillary muscles were presented in three ways: single, with one branching or with two branchings. According to these findings, it is safer to apply the left ventricule plication in the left marginal anatomic- -surgical segment (IV), oriented by I branch.