Clinical anatomy of the spatial structure of the right ventricular outflow tract.

BACKGROUND: The right ventricular outflow tract (RVOT) is located above the supraventricular crest and reaches the level of the pulmonary valve. Detailed knowledge of the RVOT spatial structure and its morphology is extremely important for cardiac invasive therapeutic procedures. OBJECTIVES: To examine the spatial structure of the RVOT using virtual models of the right ventricle (RV) interior obtained post mortem. MATERIAL AND METHODS: The study was carried out using 40 adult hearts from both sexes fixed in formalin. Donors had a negative history of cardiovascular diseases. Silicone models of the interior of the RV were made and then subjected to a digital modelling procedure using the photogrammetry technique. For each 3D model of the RV, the RVOT was extracted and measurements were performed. RESULTS: Statistical analysis demonstrated that the dimensions of the transverse (p < 0.001) and sagittal (p = 0.002) axis at the level of the upper and lower border of the RVOT differed significantly. There was also a significant difference between the right and left height of the RVOT (p = 0.009). A clear correlation was found between the volume of the RVOT and the volume of the entire RV (r = 0.718, p < 0.001). CONCLUSIONS: The obtained 3D models of the RVOT can help standardize the data related to RVOT architecture. Furthermore, they can extend knowledge about the RVOT in the field of cardiology and improve the procedures in cardiac surgery.

A smelly business: Microbiology of Adélie penguin guano (Point Thomas rookery, Antarctica).

Adélie penguins (Pygoscelis adeliae) are the most numerous flightless bird group breeding in coastal areas of Maritime and Continental Antarctica. Their activity leaves a mark on the land in the form of large guano deposits. This guano is an important nutrient source for terrestrial habitats of ice-free Antarctic areas, most notably by being the source of ammonia vapors which feed the surrounding grass, lichen and algae communities. Although investigated by researchers, the fate of the guano-associated microbial community and its role in decomposition processes remain vague. Therefore, by employing several direct community assessment methods combined with a broad culture-based approach we provide data on bacterial numbers, their activity and taxonomic affiliation in recently deposited and decayed Adélie penguin guano sampled at the Point Thomas rookery in Maritime Antarctica (King George Island). Our research indicates that recently deposited guano harbored mostly bacteria of penguin gut origin, presumably inactive in cold rookery settings. This material was rich in mesophilic enzymes active also at low temperatures, likely mediating early stage decomposition. Fresh guano colonization by environmental bacteria was minor, accomplished mostly by ammonia scavenging Jeotgalibaca sp. cells. Decayed guano contained 10-fold higher bacterial numbers with cold-active enzymes dominating the samples. Guano was colonized by uric-acid degrading and lipolytic Psychrobacter spp. and proteolytic Chryseobacterium sp. among others. Several spore-forming bacteria of penguin gut origin persisted in highly decomposed material, most notably uric-acid fermenting members of the Gottschalkiaceae family.

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

BACKGROUND: To 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. METHODS: The 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. RESULTS: We 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. CONCLUSIONS: Our 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.

The structure of the vascular system of the septomarginal trabecula in the heart of an adult.

BACKGROUND: In cardiology, the paths of the arteries penetrating the septomarginal trabecula (SMT) are especially important. They provide blood supply to the apparatus of the right atrioventricular orifice and often form anastomoses with the system of the right coronary artery. Despite this, only a few publications discuss the morphological aspect of the septomarginal trabecula, and available histological analyses seldom deal with its blood supply. OBJECTIVES: The aim of this study was to analyze the vessel structure of the septomarginal trabecula in terms of the variability of the area of the cross-section of the lumen and the muscular layer of the artery. MATERIAL AND METHODS: The study was carried out on the material of 50 human hearts from adults of both sexes. The material was divided into 4 morphological types. Histological examinations were conducted by means of classic staining methods. RESULTS: At the initial cross-section of the septomarginal trabecula, the area of the cross-section increased to half of the length of the trabecula, and then it started to decrease. This is connected with the thickening of the inner muscular layer of the artery, which proportionally takes up more area of the cross-section of the whole artery of the SMT. The total area of the cross-section of all vessels in both types examined was also the largest in the middle part of the SMT. Furthermore, the results of this study confirm the presence of a connection between both systems of coronary arteries. CONCLUSIONS: As the septomarginal trabecula passes through the lumen of the right ventricle, its arteries become exposed to the influence of the factors which may evoke a biological response from the walls of this vessel, causing the thickening of the muscular layer and, as a result, of the section of the whole artery, in particular its middle part.