Base Of Anterior Papillary Muscle Research Articles

Individual variability of vascularization of the anterior papillary muscle within the right ventricle of human heart.

BackgroundTo date there is scarce published evidence reporting the dual blood supply reaching anterior papillary muscle (APM), which descends from both major coronary arteries. Such a vascular configuration can prevent the dysfunction of right ventricular entire valvular system in case of the occlusion of proximal part of either right coronary artery (RCA) or left coronary artery (LCA). The aim of our study was to determine the vascular pattern of APM blood supply which originates from two main coronary arteries, in the context of the APM and septomarginal trabecula (SMT) topography.MethodsThe study was carried out using tissue obtained from 36 human hearts. The material was divided into four morphological types of SMT/APM arrangement. Vascularization and blood supply pattern of papillary muscle was investigated following the analysis of multiple tissue cross sections. The origin of APM arterial supply was traced back to both main coronary arteries. Cross-sectional area of the arteries was estimated at the base of APM and compared within mixed male-female population, aged 18–76.ResultsWe noted that as much as 78% of entire APM material had a blood supply vasculature originating from both LCA and RCA branches. In contrast, 22% of cases APM was supplied by a single coronary artery, while in each case it proved to be LCA. We have never found APM arterial supply provided exclusively by RCA. In case of double AMP blood supply an average of total cross-section area of the arteries branching from LCA, was noted to be in excess of two and a half times bigger in type III and more than two times bigger in type IV, as compared with the arteries originating from RCA.ConclusionsOur research confirm the possibility of double blood supply which vascularizes APM, but the finding does not necessarily apply in all cases. However, APM seems to be predominantly vascularized by arteries deriving from LCA, regardless of their morphological type.

Morphological study of the atrioventricular conduction system and Purkinje fibers in yak.

We studied the morphology of the atrioventricular conduction system (AVCS) and Purkinje fibers of the yak. Light and transmission electron microscopy were used to study the histological features of AVCS. The distributional characteristics of the His-bundle, the left bundle branch (LBB), right bundle branch (RBB), and Purkinje fiber network of yak hearts were examined using gross dissection, ink injection, and ABS casting. The results showed that the atrioventricular node (AVN) of yak located in the right side of interatrial septum and had a flattened ovoid shape. The AVN of yak is composed of the slender, interweaving cells formed almost entirely of the transitional cells (T-cells). The His-bundle extended from the AVN, and split into left LBB and RBB at the crest of the interventricular septum. The LBB descended along the left side of interventricular septum. At approximately the upper 1/3 of the interventricular septum, the LBB typically divided into three branches. The RBB ran under the endocardium of the right side of interventricular septum, and extended to the base of septal papillary muscle, passed into the moderator band, crossed the right ventricular cavity to reach the base of anterior papillary muscle, and divided into four fascicles under the subendocardial layer. The Purkinje fibers in the ventricle formed a complex spatial network. The distributional and cellular component characteristics of the AVCS and Purkinje fibers ensured normal cardiac function.

ANATOMICAL STUDY OF THE MODERATOR BAND

AbstractModerator band is a muscular trabecula which extends from interventricular septal wall to the base of anterior papillary muscle in right ventricle of heart. This study was conducted on 20 hearts from adult human cadavers. Out of 20 specimens of heart we could observe the presence of moderator band in 17 and in rest 3 it was not visible for record. Origin length, thickness and distance from tricuspid valve were noted. The average length of the moderator band was 13.82cm with the SD of 3.94 and the average thickness being 4.46cm with the SD of 1.36. The average distance from tricuspid valve was 3.6cm with the SD of 1.01. As the moderator bands, or other large trabeculations, can be major obstacle for the repair of apical ventricular septal defects, the morphometric study of moderator band may help the surgeons during surgical procedures conducted for correction of such defects.