Aortic root morphometry revisited-Clinical implications for aortic valve interventions.

The complex anatomy of the aortic root is of great importance for many surgical and transcatheter cardiac procedures. Therefore, the aim of this study was to provide a comprehensive morphological description of the nondiseased aortic root. We morphometrically examined 200 autopsied human adult hearts (22.0% females, 47.9 ± 17.7 years). A meticulous macroscopic analysis of aortic root anatomy was performed. The largest cross-section area of the aortic root was observed in coaptation center plane (653.9 ± 196.5 mm2), followed by tubular plane (427.7 ± 168.0 mm2) and basal ring (362.7 ± 159.1 mm2) (p < 0.001). The right coronary sinus was the largest (area: 234.3 ± 85.0 mm2), followed by noncoronary sinus (218.7 ± 74.8 mm2) and left coronary sinus (201.2 ± 78.08 mm2). The noncoronary sinus was the deepest, followed by right and left coronary sinus (16.4 ± 3.2 vs. 15.9 ± 3.1 vs. 14.9 ± 2.9 mm, p < 0.001). In 68.5% of hearts, the coaptation center was located near the aortic geometric center. The left coronary ostium was located 15.6 ± 3.8 mm above sinus bottom (within the sinus in 91.5% and above sinutubular junction in 8.5%), while for right coronary ostium, it was 16.2 ± 3.5 mm above (83.5% within sinus and 16.5% above). In general, males exhibited larger aortic valve dimensions than females. A multiple forward stepwise regression model showed that anthropometric variables might predict the size of coaptation center plane (age, sex, and heart weight; R2 = 31.8%), tubular plane (age and sex; R2 = 25.6%), and basal ring (age and sex; R2 = 16.9%). In conclusion, this study presents a comprehensive analysis of aortic-root morphometry and provides a platform for further research into the intricate interplay between structure and function of the aortic root.

The Impacts of Intervertebral Disc Degeneration of the Spine, Alcohol Consumption, Smoking Tobacco Products, and Glycemic Disorders on the Expression Profiles of Neurotrophins-3 and -4.

In the etiology of discogenic pain, attention is paid to the role of neurotrophic factors, which include classic neurotrophins (NTs). This study aimed to assess changes in the concentrations of NT-3 and NT-4 in the intervertebral discs (IVDs) of the lumbosacral (L/S) spine depending on the advancement of degenerative changes, pain severity, habits, and comorbidities. The study group included 113 patients who underwent microdiscectomy due to degenerative IVD disease of the L/S spine. The severity of degenerative IVD changes was assessed using the five-point Pfirrmann scale, and the pain intensity was assessed according to the visual analog scale (VAS). In turn, the control group included 81 participants from whom IVDs of the L/S section of the spine were collected post-mortem during forensic autopsy or organ donation. At the mRNA level, we noted NT-3 overexpression in the test samples compared with the controls (fold change (FC) = 9.12 ± 0.56; p < 0.05), while NT-4 transcriptional activity was decreased in the test samples compared with the controls (FC = 0.33 ± 0.07; p < 0.05). However, at the protein level, the concentrations of NT-3 (134 ± 5.78 pg/mL vs. 6.78 ± 1.17 pg/mL; p < 0.05) and NT-4 (316.77 ± 8.19 pg/mL vs. 76.92 ± 4.82 pg/mL; p < 0.05) were significantly higher in the test samples compared with the control samples. Nevertheless, the concentration of both proteins did not statistically significantly change depending on the advancement of degenerative changes and the pain intensity (p > 0.05). In addition, higher levels of NT-3 and NT-4 were noted in IVD samples from patients who consumed alcohol, smoked tobacco, were overweight/obese, or had comorbid diabetes compared with patients without these risk factors (p < 0.05). Our analysis confirmed that differences in the degenerative process of IVD, energy metabolism, and lifestyle are related to changes in the concentration profiles of NT-3 and NT-4.

Morphology of the mural and commissural atrioventricular junction of the mitral valve.

OBJECTIVE: This study investigates mitral annular disjunctions (MAD) in the atrial wall-mitral annulus-ventricular wall junction along the mural mitral leaflet and commissures. METHODS: We examined 224 adult human hearts (21.9% females, 47.9±17.6 years) devoid of cardiovascular diseases (especially mitral valve disease). These hearts were obtained during forensic medical autopsies conducted between January 2018 and June 2021. MAD was defined as a spatial displacement (≥2 mm) of the leaflet hinge line towards the left atrium. We provided a detailed morphometric analysis (disjunction height) and histological examination of MADs. RESULTS: MADs were observed in 19.6% of all studied hearts. They appeared in 12.1% of mural leaflets. The P1 scallop was the primary site for disjunctions (8.9%), followed by the P2 scallop (5.4%) and P3 scallop (4.5%). MADs were found in 9.8% of all superolateral and 5.8% of all inferoseptal commissures. The average height for leaflet MADs was 3.0±0.6 mm, whereas that for commissural MADs was 2.1±0.5 mm (p<0.0001). The microscopical arrangement of MADs in both the mural leaflet and commissures revealed a disjunction shifted towards left atrial aspect, filled with connective tissue and covered by elongated valve annulus. The size of the MAD remained remarkably uniform and showed no correlation with other anthropometric factors (all p>0.05). CONCLUSIONS: In the cohort of the patients with healthy hearts, MAD is present in about 20% of all studied hearts. The MADs identified tend to be localised, confined to a single scallop. Moreover, MADs in the commissures are notably smaller than those in the mural leaflet.

Analysis of various radiological age-assessment methods in children, adolescents and young adults regarding the differences between the sexes and sides of the body - A comparative review.

A total of 76 articles published within the last twenty years, indexed in the PubMed and ResearchGate databases, were reviewed in order to compare medical imaging-based methods of age estimation of children, adolescents and young adults. The evaluated studies were analyzed for any statistically significant differences between the sexes and sides of the body, sample sizes, and population age. Irrespective of the evaluation method, there were some studies that showed a statistically significant differences in ossification stages between the male and female groups. Most of the studies whose authors conducted a statistical analysis demonstrated no significant differences between the left and right side of the body.

Overkilling: A specific type of homicide - Constructing the definition: Perpetrator, weapon and circumstances.

Overkilling in the Forensic Medicine is known as a specific type of homicide where the number of inflicted injuries greatly surpasses the number of fatal ones. Conducted research aimed to create a unified definition of the phenomenon and its classification criteria by analysing a vast majority of variables concerning its various characteristics. From the population of homicide victims autopsied in the authors' research facility a number of 167 cases were chosen consisting of both overkilling and other homicides. 70 cases were thoroughly analysed based on the completed court files, autopsy protocols and photographs. Second part of the research concerned the facts regarding the perpetrator, used weapon and the circumstances of the act. Conclusions of the conducted analysis allowed to add further characteristics to the overkilling definition: the perpetrators were almost exclusively men, around 35 of age, not related to the victim but might have been in a close relationship with them, often a conflicted one. They did not threaten the victim before the incident. Mostly perpetrators were not intoxicated, and they tried to cover up the homicide in various ways. Perpetrators of overkilling were in most cases mentally disturbed (and thus stated insane), had different levels of intelligence but also a low level of planning before the act - rarely taking actions as preparing the weapon in advance, choosing the scene or luring in the victim.

Aortic valve fenestrations: Macroscopic assessment and functional anatomy study.

Aortic valve fenestrations are defined as a loss of aortic valve leaflet tissue. They are a common but overlooked finding with unclear significance. The aim of this study was to investigate the varied functional anatomies of aortic valve fenestrations. A total of 400 formalin-fixed autopsied human hearts were macroscopically assessed and the function of the aortic valve of 16 reanimated human hearts were imaged using Visible Heart® methodologies. Aortic valve leaflet fenestrations were present in 43.0% of autopsied hearts (in one leaflet in 24.0%, in two leaflets 16.0%, in all leaflets 3.0%). Fenestrations were mostly present in left (25.5%) followed by right (23.3%) and noncoronary leaflet (16.3%). In 93.8% of cases, the fenestrations form clusters and were mainly located at the free edge of the leaflet in the commissural area (95.4%). Hearts with aortic valve fenestrations had significantly larger aortic valve diameters and aortic valve areas (p < 0.001). The average surface area sizes of fenestrations were 23.8 ± 16.6 mm2 , and the areas were largest for left followed by right and noncoronary leaflet fenestrations (p < 0.001). The fenestration areas positively correlated with donor age (r = 0.31; p = 0.02). Significant hypermobility and subjective weakening of the leaflet adhesion levels of the fenestrated regions were observed. In conclusion, fenestrations of the aortic leaflets are frequent, and their sizes may be significant. They occur in all age groups, yet their size increase with aging. Fragments of leaflets with fenestrations show different behaviors during the cardiac cycle versus unchanged areas.

The fusion of ossification centers - A comparative review of radiographic and other imaging modalities of age assessment in living groups of children, adolescents, and young adults.

A total of 227 articles published within the last twenty years, indexed in the PUBMED and Researchgate databases, were reviewed for the purpose of comparing medical imaging-based methods of age estimation. The evaluated studies were analyzed in terms of the assessed parts of the body, age, and epiphyseal fusion ages in children, adolescents, and young adults. Our analysis showed that an overwhelming majority of studies had been based on computed tomography and magnetic resonance imaging. A comparison of the studies showed that, irrespective of the imaging modality and the nationality of study population cohorts, the rates of development and the ages at which the process of ossification begins and ends show certain trends.

Pulmonary valve morphometry revisited: Clinical implications for valvular and supravalvular interventions.

In this cadaver-based study, we aimed to present a novel approach to pulmonary valve (PV) anatomy, morphometry, and geometry to offer comprehensive information on PV structure. The 182 autopsied human hearts were investigated morphometrically. The largest PV area was seen for the coaptation center plane, followed by basal ring and the tubular plane (626.7 ± 191.7 mm2 vs. 433.9 ± 133.6 mm2 vs. 290.0 ± 110.1 mm2 , p < 0.001). In all leaflets, fenestrations are noted and occur in 12.5% of PVs. Only in 31.3% of PVs, the coaptation center is located in close vicinity of the PV geometric center. Similar-sized sinuses were found in 35.7% of hearts, in the remaining cases, significant heterogeneity was seen in size. The mean sinus depth was: left anterior 15.59 ± 2.91 mm, posterior: 16.04 ± 2.82 mm and right anterior sinus: 16.21 ± 2.81 mm and the mean sinus height: left anterior 15.24 ± 3.10 mm, posterior: 19.12 ± 3.79 mm and right anterior sinus: 18.59 ± 4.03 mm. For males, the mean pulmonary root perimeters and areas were significantly larger than those for females. Multiple forward stepwise regression model showed that anthropometric variables might predict the coaptation center plane (sex, age, and heart weight; R2  = 33.8%), tubular plane (sex, age, and BSA; R2  = 20.5%) and basal ring level area (heart weight and sex; R2  = 17.1%). In conclusion, the largest pulmonary root area is observed at the coaptation center plane, followed by the basal ring and tubular plane. The PV geometric center usually does not overlap valve coaptation center. Significant heterogeneity is observed in the size of sinuses and leaflets within and between valves. Anthropometric variables may be used to predict pulmonary root dimensions.

Overkilling: A specific type of homicide - Constructing the definition: Injuries and victim.

Overkilling in the Forensic Medicine field is known as a specific type of homicide where the number of inflicted injuries greatly surpasses the number of fatal ones. Conducted research aimed to create a unified definition of the phenomenon and its classification criteria by analysing a vast majority of data concerning its various characteristics. From the population of homicide victims autopsied in the authors' research facility a number of 167 cases were chosen consisting of both overkilling and other homicides. 70 cases were thoroughly analysed based on the completed court files, autopsy protocols and photographs. First part of the research concerned the facts regarding the injuries sustained and the victim's characteristics. Conclusions of the statistical analysis allowed to characterize overkilling as a type of homicide where the number of injuries (sharp or blunt) is several times higher than the number of fatal injuries. Sharp force injuries predominate, and are often localized on the torso, neck and limbs, while blunt force injuries are localized mostly on the head. There is no significant dominance between the sexes of the victims, mostly they are in their 40-50's. Victims with reduced abilities to resist predominated (mostly women), which is correlated with the position of their body (lying or sitting) at the begging of the incident. Also overkilling victims more often suffer from defensive injuries and post mortem trauma.

Restraint asphyxia. An analysis of the circumstances and mechanism of death in agitated, physically restrained individuals. / Asfiksja restrykcyjna. Analiza okolicznosci i mechanizmu smierci osób pobudzonych psychoruchowo, w trakcie obezwladniania z uzyciem sily.

Recent years saw frequent media reports of young people who die while they are being arrested by the police. Death in these circumstances affects people who are agitated and restrained with the use of force, with their autopsies indicating no unequivocally traumatic cause of death. The goal of this study was to identify the mechanism and circumstances of sudden deaths in agitated individuals who are being restrained. Ten cases evaluated at our center since 2010 were included in this study: nine involved forensic postmortem examination and one involved casefile analysis. In each case there was sudden cardiac arrest or at least a loss of consciousness, and the cardiopulmonary resuscitation proved ineffective. In six cases the cause of agitation was acute psychosis, in four it was an effect of narcotics, usually in high concentration. Conjunctival petechiae were detected in only five cases. The most probable cause of death in the evaluated cases was the combination of physical exertion caused by pathological psychomotor agitation and forcible restraint, hindering the function of the respiratory system. This mechanism is known as restraint asphyxia.

Neuropathological Changes in the Brains of Suicide Killers.

BACKGROUND: Homicide combined with subsequent suicide of the perpetrator is a particular form of interpersonal violence and, at the same time, a manifestation of extreme aggression directed against oneself. Despite the relatively well-described individual acts of homicide and suicide, both in terms of psychopathology and law, acts of homicide and subsequent suicide committed by the same person are not well-studied phenomena. The importance of emotional factors, including the influence of mental state deviations (psychopathology), on this phenomenon, is discussed in the literature, but still there is relatively little data with which to attempt neuropathological assessments of the brains of suicide killers. This paper is dedicated to the issue based on the neuropathological studies performed. METHODS: We analyzed a group of murder-suicides using histochemical and immunohistochemical methods. RESULTS: The results of our research indicate the presence of neurodegenerative changes including multiple deposits of ß-amyloid in the form of senile/amyloid plaques and perivascular diffuse plaques. CONCLUSIONS: Neurodegenerative changes found in the analyzed brains of suicide killers may provide an interesting starting point for a number of analyses. The presence of neurodegenerative changes at such a young age in some murderers may suggest preclinical lesions that affect cognitive functions and are associated with depressed moods.

Mutual Arrangements of Coronary Blood Vessels within the Right Atrial Appendage Vestibule.

BACKGROUND: The aim of our study was to investigate the presence and mutual relationships of coronary vessels within the right atrial appendage (RAA) vestibule. METHODS: We examined 200 autopsied hearts. The RAA vestibule was cross-sectioned along its isthmuses (superior, middle, and inferior). RESULTS: The right coronary artery (RCA) was present in 100% of the superior RAA isthmuses but absent in 2.0% of hearts within the middle isthmus and in 6.5% of hearts within the inferior RAA isthmus. Its diameter was quite uniform along the superior (2.6 ± 0.8 mm), middle (2.9 ± 1.1 mm), and inferior (2.7 ± 0.9 mm) isthmuses (p = 0.12). The location of the RCA varied significantly, and it was sometimes accompanied by other accessory coronary vessels. In all the isthmuses, the RCA ran significantly closer to the endocardial surface than to the epicardial surface (p < 0.001). At the superior RAA isthmus, the artery was furthest from the right atrial endocardial surface and this distance gradually decreased between the middle RAA isthmus and the inferior RAA. CONCLUSIONS: This study was the most complex analysis of the mutual arrangements and morphometric characteristics of coronary blood vessels within the RAA vestibule. Awareness of additional blood vessels within the vestibule can help clinicians plan and perform safe and efficacious procedures in this region.

Thickness of the left atrial wall surrounding the left atrial appendage orifice.

INTRODUCTION: The aim of this study was to investigate the thickness of the left atrial wall surrounding the left atrial appendage (LAA) orifice. METHODS AND RESULTS: The tissue thickness around the LAA orifice was measured at four points (superior, inferior, anterior, and posterior) in 200 randomly selected autopsied human hearts. The thickest tissue was observed at the anterior point (3.17 ± 1.41 mm), followed by the superior (2.47 ± 1.00 mm), inferior (2.22 ± 0.80 mm) and posterior (2.22 ± 0.83 mm). The chicken wing LAA type was associated with the lowest thickness at the superior point compared to the cauliflower and arrowhead shapes (p = .024). In hearts with an oval LAA orifice, the atrial wall was significantly thicker in all points than in specimens with a round LAA orifice (p > .05). Both the LAA orifice anteroposterior diameter and orifice surface area were negatively correlated with the tissue thickness in the anterior (r = -.22, p = .004 and r = -.23, p = .001) and posterior points (r = -.24, p = .001 and r = -.28, p = .005). Endocardial surface roughness was commonly in the inferior pole of the LAA orifice (75.5% of cases), while they are much less prevalent in other sectors around the orifice (anterior: 17.5%), superior: 4.0%, and posterior: 1.5%). CONCLUSIONS: Although a significant heterogeneity in the atrial wall thickness around the LAA orifice was observed, the thickness in the respective points is quite conservative and depends only on LAA orifice size and shape, as well as LAA body shape. Thin atrial wall and endocardial surface roughness might challenge invasive procedures within this region.

Morphology of the Left Atrial Appendage: Introduction of a New Simplified Shape-Based Classification System.

BACKGROUND: The left atrial appendage (LAA) is a heart structure with known prothrombogenic and pro-arrhythmogenic properties. AIM: The aim of this study was to evaluate the specific anatomy of the LAA and to create a simple classification system based on the shape of its body. METHOD AND RESULTS: This study investigated 200 randomly selected autopsied human hearts (25.0% females, 46.6±19.1 years old). Three (3) types of LAAs were distinguished: the cauliflower type (no bend, limited overall length, compact structure [36.5%]); the chicken wing type (substantial bend in the dominant lobe [37.5%]), and the arrowhead type (no bend, one dominant lobe of substantial length [26.0%]). Additional accessory lobes were present in 55.5% of all LAAs. Significant variations between category types were noted in LAA length (chicken wing: 35.7±9.8 mm, arrowhead: 30.8±10.1 mm, cauliflower: 22.3±9.6 mm [p<0.001]) and in the thickness of pectinate muscles located within the LAA apex (arrowhead: 1.2±0.7 mm; cauliflower: 1.1±0.6 mm; chicken wing: 0.9±0.6 mm [p<0.001]). Left atrial appendage volume and orifice size were not affected by the type of LAA shape. The age of the donor was positively correlated with LAA volume (r=0.29, p=0.005), body length (r=0.26, p=0.012), and area of the orifice (r=0.36, p<0.001). Donors with an oval LAA orifice were significantly older than those with round orifices (50.2±16.6 vs 43.7±20.4 years [p=0.014]) and had significantly heavier hearts (458.2±104.8 vs 409.6±114.1g [p=0.002]). CONCLUSIONS: This study delivered a new simple classification system of the LAA based on its body shape. An increase in age and heart weight was associated with LAA enlargement and a more oval-shaped orifice. Results of current study may help to estimate the different thrombogenic properties associated with each LAA type and be an assistance during planning and performing interventions on LAA.

Topographical anatomy of the right atrial appendage vestibule and its isthmuses.

INTRODUCTION: The right atrial appendage (RAA) vestibule is an area located in the right atrium between the RAA orifice and the right atrioventricular valve annulus and may be a target for invasive transcatheter procedures. METHODS AND RESULTS: We examined 200 autopsied human hearts. Three isthmuses (an inferior, a middle, and a superior isthmus) were detected. The average length of the vestibule was 67.4 ± 10.1 mm. Crevices and diverticula were observed within the vestibule in 15.3% of specimens. The isthmuses had varying heights: superior: 14.0 ± 3.4 mm, middle: 11.2 ± 3.1 mm, and inferior: 10.1 ± 2.7 mm (p < .001). The superior isthmus had the thickest atrial wall (at midlevel: 16.7 ± 5.6 mm), the middle isthmus had the second thickest wall (13.5 ± 4.2 mm), and the inferior isthmus had the thinnest wall (9.3 ± 3.0 mm; p < .001). This same pattern was observed when analyzing the thickness of the adipose layer (superior isthmus had a thickness of 15.4 ± 5.6 mm, middle: 11.7 ± 4.1 mm and inferior: 7.1 ± 3.1 mm; p < .001). The average myocardial thickness did not vary between isthmuses (superior isthmus: 1.3 ± 0.5 mm, middle isthmus: 1.8 ± 0.8 mm, inferior isthmus: 1.6 ± 0.5 mm; p > .05). Within each isthmus, there were variations in the thickness of the entire atrial wall and of the adipose layer. These were thickest near the valve annulus and thinnest near the RAA orifice (p < .001). The thickness of the myocardial layer followed an inverse trend (p < .001). CONCLUSIONS: This study was the first to describe the detailed topographical anatomy of the RAA vestibule and that of its adjoining isthmuses. The substantial variability in the structure and dimensions of the RAA isthmuses may play a role in planning interventions within this anatomic region.

Morphometric characteristics of myocardial sleeves of the pulmonary veins.

BACKGROUND: The pulmonary veins are covered by a myocardial layer, which is often an electrical substrate for atrial fibrillation. The aim of this study was to study the morphologic characteristics of the myocardial sleeves of pulmonary veins by examining a large group of freshly autopsied human material. METHODS AND RESULTS: The study macroscopically examined a total of 498 pulmonary veins draining the left atrium (120 unpreserved human hearts). In 75.0% of specimens, a classical pulmonary venous pattern was observed. The remainder of specimens either had an additional middle right pulmonary vein (20.0% of cases) or a common left pulmonary vein (5.0% of cases). Among all the veins seen in the classical pulmonary venous drainage type, the left superior pulmonary vein had the longest myocardial sleeves (9.4 ± 4.6 mm; coverage = 60.1 ± 19.4%), followed by the left inferior pulmonary vein (6.6 ± 3.5 mm; coverage = 47.6 ± 18.3%), the right superior pulmonary vein (6.0 ± 2.7 mm; coverage = 50.5 ± 13.9%) and then the right inferior pulmonary vein (5.0 ± 2.8 mm; coverage = 45.6 ± 16.2%; analysis of variance p < .001). In hearts with an additional right pulmonary vein, this vessel had the shortest myocardial sleeves (2.7 ± 1.1 mm; coverage = 36.0 ± 11.6%). In hearts with a common left pulmonary vein, the myocardial sleeves had the longest course for the common vein (13.7 ± 4.4 mm; coverage = 79.7 ± 4.9%). CONCLUSIONS: Myocardial sleeves of the pulmonary veins were seen in each examined specimen, however, their length varied significantly. In hearts with a classical venous drainage pattern, the left superior pulmonary vein had the longest sleeves. When present, an additional middle right pulmonary vein had the shortest myocardial sleeves, while the left common pulmonary vein had the longest sleeves.

Topography of the oblique vein of the left atrium (vein of Marshall).

BACKGROUND: The oblique vein of the left atrium is of interest for electrophysiologists working in the field of both basic science and clinical practice. AIMS: We aimed to examine the topographic anatomy of the oblique vein and to assess the vein's location and relationships with surrounding cardiac structures. METHODS: A total of 200 autopsied adult human hearts were examined. RESULTS: The oblique vein was observed in 71% of the hearts. Its mean (SD) total length was 30.8 (13.6) mm. In hearts with the oblique vein, a larger distance was observed between the left inferior pulmonary vein (LIPV) and great cardiac vein (mean [SD], 18.6 [5.1] mm vs 16.3 [4.8] mm; P = 0.004), between the left atrial appendage (LAA) and LIPV (mean [SD], 17.8 [6.8] mm vs 15.1 [5.2] mm; P = 0.007), and between the LAA and left superior pulmonary vein (LSPV; mean [SD], 28.5 [7.2] mm vs 21.3 [6.4] mm; P <0.001). Hearts with a classic pattern of left­sided pulmonary veins were categorized into 4 types based on the length of oblique vein extension. In type I, the vein extended below the level of the LIPV (21.9%); in type II, to the level of the LIPV (47.7%); in type III, to the level of the interpulmonary area (17.2%); and in type IV, to the level of the LSPV (13.3%). In each type, the distance between the oblique vein and LIPV was shorter than that between the oblique vein and LAA Conclusions: The oblique vein had a variable course and differing lengths of extension. The presence of the oblique vein was connected with a greater distance between the left­sided pulmonary veins and LAA.

Anatomy of the left atrial ridge (coumadin ridge) and possible clinical implications for cardiovascular imaging and invasive procedures.

BACKGROUND: The left atrial ridge is a structure located in the left atrium between the left-sided pulmonary veins ostia and the orifice of the left atrial appendage. Since it was commonly misdiagnosed as a thrombus, the ridge is also known as the "coumadin" or "warfarin" ridge. The left atrial ridge is a potential source of arrhythmias and can be an obstacle in ablation procedures. This study aimed to provide information about the occurrence and spatial morphometric characteristics of the left atrial ridge. METHODS AND RESULTS: The macroscopic morphology of the left atrial ridge was assessed in 200 autopsied human hearts. The ridge was observed in 59.5% of specimens and was absent in the remaining 40.5% of cases. The mean length of the ridge was 22.4 ± 5.1 mm. It was wider at its inferior sector when compared to its superior sector (9.1 ± 5.0 vs 7.9 ± 3.2 mm; P = .028). The total wall thickness measured at the cross section of the ridge was significantly larger in the inferior than in superior sector (6.2 ± 3.5 vs 4.3 ± 1.8 mm; P < .001), although the myocardial thickness was significantly larger at the superior sector (3.1 ± 1.4 vs 1.9 ± 0.9 mm in inferior sector, P < .001). CONCLUSION: The left atrial ridge is a variable structure, present in 59.5% of humans. The ridge is significantly wider and thicker at its inferior sector, although the actual myocardial layer present within the ridge is thinner at this location. Knowledge about the left atrial ridge morphology is key in avoiding unnecessary interventions or complications during invasive procedures.

Quadricuspid pulmonary valve: macroscopic and microscopic morphometric examination.

A quadricuspid pulmonary valve obtained upon autopsy of a 26-year-old male was examined. The macroscopic evaluation revealed three normal (posterior, right anterior and left anterior) leaflets and one additional leaflet of the pulmonary valve. Except that, the heart showed neither other anatomical variabilities nor any signs of heart disease. The additional leaflet was located between the left anterior and right anterior leaflets and was significantly smaller in size. Under the microscope, all leaflets showed preservation of the typical, layered structure. The thickness and extracellular matrix composition of the particular layers differed between the leaflets. Right ventricular myocardium (myocardial sleeves) exceeded the level of the hinge line in all three normal leaflets, which was not observed in the additional leaflet. Autonomic nerves and ganglia were not seen in the perivalvular epicardial adipose tissue surrounding the additional leaflet. The sinus wall of all the leaflets revealed typical organization of collagen bundles as well as elastic fibers and showed no signs of disruption. The abnormality seen in the structure of the pulmonary valve is likely to be a result of disturbed embryonic development and may affect the clinical management of patients with such variation.

Topographic characteristics of the left atrial medial isthmus.

BACKGROUND: The purpose of this study was to provide detailed topography of the left atrial medial isthmus (situated between the right inferior pulmonary vein ostium and the medial part of the mitral annulus). METHODS: Two hundred human hearts (Caucasian, 22.5% females, 48.7 ± 4.9 years old) were investigated. RESULTS: The mean length of the medial isthmus was 42.4 ± 8.6 mm. Additionally, the medial isthmus line was divided by the oval fossa into three sections with equal mean lengths (upper: 14.2 ± 7.2 vs middle: 14.1 ± 6.1 vs lower: 14.9 ± 4.6 mm; P > .05). The left upper section of the atrial wall was thinner than the lower section (2.5 ± 1.1 vs 3.4 ± 1.6 mm; P < .0001). This study noted three separate spatial arrangements of the isthmus line. Type I (54.5%) had an oval fossa located outside the isthmus line; type II (32.5%) had an oval fossa crossed by the isthmus line, and type III (13.0%) had an oval fossa rim located tangentially to the isthmus line. In 68.5% of the examined specimens, the isthmus area had a smooth surface. Conversely, the remaining 31.5% had additional structures within its borders such as diverticula, recesses, and tissue bridges. CONCLUSION: This study is the first to describe the morphometric and topographical features of the left atrial medial isthmus. Interventions within the medial isthmus line should be performed cautiously, especially when they are transected by the oval fossa (32.5%). Careful navigation of the area is also recommended due to the possibility of existent additional structures. The latter could lead to catheter entrapment during ablation procedures.