Morphological Assessment and Possible Clinical Implications of the Left Ventricle Papillary Muscles. Study in a Colombian Population Sample

SUMMARY: Papillary muscles in the left ventricle present multiple anatomic expressions that are relevant for medical fields focusing on the understanding of clinical events involving these structures. Here, the aim was to perform a morphological characterization of the left ventricle papillary muscles in a sample of Colombian population. In the study were included eighty-two hearts from male individuals who underwent autopsy at the Institute of Legal Medicine and Forensic Sciences in Bucaramanga, Colombia. In each heart was carefully performed a longitudinal incision on the obtuse margin to visualize the papillary muscles. Data set was registered, and analysis of the continuous and categorical variables was carried out. Single anterior papillary muscle was observed in 74 samples (90.2 %) whereas this represented only 48 specimens (58.5 %) for the posterior papillary muscle (p = 0.3). Mean length and breadth of the anterior muscle were 29.9 ± 4.94 and 11.74 ± 2.75 mm, and those for the posterior muscle were 27.42 ± 7.08 and 10.83 ± 4.08 mm. Truncated apical shape was the most frequent type observed on the papillary muscles, anterior 41 (50 %) and posterior 37 (45.1 %), followed by flat-topped in the anterior 25 (30.5 %) and bifurcated in posterior muscle 14 (17.1 %). A mean of 9.04 ± 2.75 chordae raised from the anterior and 7.50 ± 3.3 from posterior papillary muscle. In our study we observed a higher incidence of single papillary muscles and slightly larger dimensions than information reported in the literature. The anatomic diversity of the papillary muscles should be considered for the correct image interpretation, valve implantation and performance evaluation on myocardial ischemic events.

Los músculos papilares del ventrículo izquierdo presentan múltiples expresiones anatómicas que son relevantes para las áreas médicas que se centran en la comprensión de los eventos clínicos que involucran estas estructuras. El objetivo fue realizar una caracterización morfológica de los músculos papilares del ventrículo izquierdo en una muestra de población colombiana. En el estudio se incluyeron ochenta y dos corazones de individuos masculinos a los que se les realizó autopsia en el Instituto de Medicina Legal y Ciencias Forenses de Bucaramanga, Colombia. En cada corazón se realizó cuidadosamente una incisión longitudinal en el margen obtuso para visualizar los músculos papilares. Se registró el conjunto de datos y se realizó el análisis de las variables continuas y categóricas. Se observó un solo músculo papilar anterior en 74 muestras (90,2 %), mientras que este rasgo se presentó en 48 muestras (58,5 %) para el músculo papilar posterior (p = 0,3). La longitud y anchura media del músculo anterior fueron 29,9 ± 4,94 y 11,74 ± 2,75 mm, y las del músculo posterior fueron 27,42 ± 7,08 y 10,83 ± 4,08 mm. La forma apical truncada fue el tipo más frecuente observado en los músculos papilares, anterior 41 (50 %) y posterior 37 (45,1 %), seguido de la forma plana en los 25 anteriores (30,5 %) y bifurcada en el músculo posterior 14 (17,1 %). Una media de 9,04 ± 2,75 cuerdas elevadas desde el músculo papilar anterior y 7,50 ± 3,3 desde posterior. En nuestro estudio observamos una mayor incidencia de músculos papilares únicos y dimensiones ligeramente mayores que la información reportada en la literatura. La diversidad anatómica de los músculos papilares debe ser considerada para la correcta interpretación de imágenes, implantación valvular y evaluación del desempeño en eventos isquémicos miocárdicos.

Comparative anatomy of the mitral valve in four species (human, ovine, porcine and canine): A pre-clinical perspective.

This study aimed to provide comparative anatomical data on the mitral valve and to substantiate the choice between large species for pre-clinical testing of cardiac devices. Different anatomical parameters of the anterior and posterior leaflets, chordae and papillary muscles were measured to characterize the anatomy of the mitral valve in 10 individuals for each four species. Ratios were calculated and used to circumvent the interspecies variations of body and heart size and weight. The results underline many relevant anatomical similarities and differences between man and the three animal species. We confirm that the porcine species is a better model based on anatomical measurements. But many parameters should be considered depending on the shape, size and purpose of the device. The mitral and aortic valve are closer than in man leading to potential damage of the aortic valve by a mitral device. The ovine mitral annulus is more flattened and would sustain more mechanical forces on a round-shaped stent. The anterior and posterior leaflets have comparable height in the animal species leading to more space for implantation. The porcine valve has more chordae allowing less space around the valve for a transcatheter stent. Our observations introduce new comparative data in the perspective of the choice of a large animal model for pre-clinical testing of mitral devices. They are very helpful for all cardiologists, surgeons or engineers who need to understand the reasons for success or failure of a device and to have key elements of discussion.

Morphology of papillary muscles in the ventricles of heart - a review and meta-analysis.

OBJECTIVE: To review the morphology of papillary muscles in both the ventricles of heart. METHODS: The articles were collected from databases such as MEDLINE etc. using Google as the search engine. Keywords used were papillary muscle morphology, papillary muscle dimensions, papillary muscle blood supply, papillary muscle histology, papillary muscle development and papillary muscle biomechanical properties. Studies were included if they assessed the aforesaid features of papillary muscles. Thirty-four studies were included in the review. Meta-analysis was done for number of right and left ventricular papillary muscles and dimensions of right ventricular papillary muscles. The data obtained from these studies was synthesized, pooled and all analyses were performed using R Statistical Software (v4.1.2; R Core Team 2021) with R package meta version 5.5-0. RESULTS: Marked difference existed between papillary muscles of right and left ventricles. In right ventricle, one anterior (76%), one posterior (38%) and one septal (30%) papillary muscle were most common. In left ventricle, one anterior (46%) and two posterior papillary muscles (26%) were most common. In both the ventricles, commonly observed gross appearances of papillary muscles were conical and flat-topped. Papillary muscles were lengthier in left ventricle than right ventricle. Anterior papillary muscle was 1.36cm long, 1.36cm broad and 0.64cm thick in right ventricle. It was the largest in both right and left ventricles. CONCLUSION: The morphology and measurements of papillary muscles vary significantly. Thorough knowledge of these variations will help surgeons to determine appropriate surgical repair procedures for the valve and subvalvular apparatus.

An unusual origin of a papillary muscle of the right ventricle.

Knowledge of anatomical variations of the heart are important to cardiac surgeons, cardiologists, and radiologist. During routine dissection of a 77-year-old male cadaver, we observed an unusual origin of a papillary muscle of the right ventricle arising from the atrioventricular aspect of the moderator band. This papillary muscle was 6.7mm long and 2.6mm wide. It gave rise to two chordae tendineae: one to the inferior (posterior) papillary muscle of the right ventricle and one directly to the inferior (posterior) leaflet of the tricuspid valve. Variants of the internal anatomy of the heart as exemplified in the present case report should be born in mind during image interpretation and invasive procedures of the right ventricle of the heart.

Tricuspid valve complex- a study on its variations in North Indian population and clinical implications

Since cardiovascular diseases are emerging as major causes of morbidity and mortality in the modern era, emphasis is laid on understanding normal as well as variant cardiac anatomy. Moreover, the advancement in diagnostic and therapeutic cardio-invasive techniques have prompted the revision of our existing knowledge and understanding about fine details of atrio-ventricular, valvular and chordo-papillary complexes. This study is an endeavour to establish the morphology of the tricuspid valve and chordo-papillary complex of the right ventricle in north Indian population and to compare it with previously provided data by different researchers. The study was conducted using 52 formalin-fixed adult human hearts. The presence, number, shapes, length, number of additional heads of the papillary muscles were observed. The morphology of the tricuspid valve was also noted. The morphology and morphometry of the tricuspid valve and papillary muscles were defined. Awareness of such information, whether normal or variant, is considered a prerequisite for successful, uncomplicated cardiac surgeries and interventional radiology

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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 Adaptive Remodeling of the Anterior Mitral Leaflet and Chordae Tendineae Is Associated with Mitral Valve Function in Advanced Ischemic and Nonischemic Dilated Cardiomyopathy.

The degree or nature of functional mitral regurgitation (MR) is not necessarily correlated with the size or function of the left ventricle (LV). We hypothesized that the anatomical structure of the mitral valve (MV) complex might play a role in functional MR in ischemic or nonischemic dilated cardiomyopathy (DCM).The structure of the LV and MV complex in DCM patients (n = 29) was assessed using electrocardiogram-gated 320-slice computed tomography and was compared with that in healthy patients (n = 12). Twenty-five DCM patients with mild or low MR (DCM-lowMR) had markedly greater length, diameter, and sphericity index of the LV and a larger tenting area than the controls. The distance between the papillary muscle (PM) tip and the mitral annular plane was not different between DCM-lowMR and normal hearts despite the greater LV length observed in DCM-lowMR. Furthermore, DCM-lowMR had markedly longer chordae tendineae (DCM-lowMR: 24 [20-26] mm; controls: 14 [13-16] mm; P < 0.01) and larger anterior leaflets (DCM-lowMR: 30 [27-31] mm; controls: 22 [20-24] mm; P < 0.01), thus suggesting the adaptive remodeling of the MV complex. Four DCM patients with moderate-severe MR had unbalanced remodeling, such as excessive LV dilatation, short anterior mitral leaflets, and short chordae tendineae.The development of functional MR might be associated with the remodeling of LV and MV components, such as the PMs, chordae tendineae, or anterior MV leaflets. Detailed anatomical assessments of the LV and MV complex would contribute to the adequate staging of ischemic or nonischemic DCM.

Gross anatomy of the heart of the alpaca (Vicugna pacos, Linnaeus 1758).

The available information about anatomical characteristics of the cardiovascular system of the alpaca (Vicugna pacos, Linnaeus 1758) is scarce. The general objective of this work was to describe its heart anatomy. We dissected six adult animals and five neonates. The heart of the alpaca was located in the middle mediastinum, with a craniocaudal extension from the third to the sixth rib. No ligament that connected the fibrous pericardium to the sternum or to the diaphragm was detected. In the right atrium, there was a developed crista terminalis and small pectinate muscles. In the right ventricle, the septomarginal trabecula was very large. From the proximities of the interventricular septum arose small septomarginal trabeculae that ended in carnous trabeculae of the septal wall. The left atrium included little developed pectinate muscles. On the left ventricle, both papillary muscles were bilobed. Two left septomarginal trabeculas were detected in this ventricle. The left subclavian artery was originated from the aortic arch separately from the brachiocephalic trunk, and bicarotid trunk was present. The other branches of the subclavian artery were similar to the domestic ruminants. The arterial supply of the heart was of the right type. In conclusion, the heart anatomy of alpaca and the irrigation of thoracic cavity were more similar to those of old world camels and different from domestic ruminants.

Papillary muscle rupture following acute myocardial infarction: Anatomic, echocardiographic, and surgical insights.

Papillary muscle (PM) rupture is a rare complication of acute myocardial infarction which carries an excessive mortality rate. Optimal outcomes require rapid diagnosis and prompt surgical referral, and in this regard, echocardiography plays a crucial role. Comprehensive echocardiographic examination of the patient with PM rupture consists of identification of the ruptured PM segment, visualization of flail mitral valve segment(s), evaluation of mitral regurgitation severity, and assessment of left ventricular systolic function. This article discusses anatomic and echocardiographic features as well as the surgical management of PM rupture.

Morphology and Classification of Right Ventricular Bands in the Domestic Dog (Canis familiaris).

Ventricular bands, also designated as 'false tendons', are described as single or multiple strands that cross the ventricles and have no connection to valvular cusps. Previous work indicates these strands are present in the ventricles of humans and some animal hearts and not always associated with cardiac pathologies. Despite these previous studies, the published literature is limited in documenting the morphology of these strands and incidence in animals. In this study, examination of 89 hearts showed six types of ventricular bands in the right ventricle of the domestic dog. These bands were classified according to their prevalence and points of attachment. Type I extended from the interventricular septum to the ventricular free wall, type II connected a musculus papillaris parvus to the ventricular free wall and type III connected trabeculae carneae on the interventricular septum. Type IV connected the trabeculae carneae on the ventricular free wall, type V interconnected papillary muscles and type VI connected the interventricular septum to a papillary muscle. While the study of these ventricular bands provided additional information on the cardiac anatomy of the domestic dog, it also showed their clinical importance. Several studies have proposed that their position in the ventricle may interfere with cardiac catheterization and pacemaker lead placement or be misinterpreted during echocardiography.

The first descriptions of various anatomical structures and embryological remnants of the heart: A systematic overview.

In the present study a brief overview of the history regarding the development of the knowledge of the macroscopic and microscopic anatomical elements of the heart along with some embryological remnants of the heart has been conducted. The evolution of the awareness as regards the various anatomical and embryonic structures of the heart began from Greek medico-philosophers, such as Hippocrates, Herophilus, Erasistratus and Galen, however, such knowledge was enpowered from the meticulous study of philosophers and physicians until the era of modern anatomy. In specific, the following anatomical and embryological structures are displayed: aortic and pulmonary valve, auricles, bundle of Kent, cardiac nerves, conduction system of the heart, ductus arteriosus, intervenous tubercle of Lower, left atrial oblique vein and ligament of Marshall, limbus of fossa ovalis, mitral and tricuspid valve, nodes or nodules of Arantius, ovale foramen, septomarginal trabecula, sinus of Valsava, small cardiac veins or vessels of Thebesius, tendinous chordae and papillary muscles, tendon of the valve of the inferior vena cava and triangle of Koch, valve of the coronary sinus, valve of the inferior vena cava.

The ability of mitral papillary muscle positions to explain QRS complex characteristics in humans.

Anatomical location of the conduction system may influence the characteristics of the depolarization and thus characteristics of the QRS complex. It is known that in the heart, there are electro-anatomical relationships, such as relationships among the molecular, genetic and anatomic components of the conduction system and papillary muscles. This review aims to discuss how knowledge of the electro-anatomical developmental relationships helps in understanding the known variability to be observed in the human electrocardiograms.

Atypical Chordae Tendineae of the Canine (Canis familiaris) Right Atrioventricular Valve.

The canine right atrioventricular valve cusps are anchored to papillary muscles by chordae tendineae. During ventricular systole, these tendineae keep the cusps from being pushed into the atrium. While this is the general description for chordae tendineae, several researchers have briefly documented chordae tendineae in animal and human hearts that do not attach to papillary muscles. In the 39 canine hearts examined, atypical chordae tendineae were observed in two hearts. In both dogs, a single stranded chordae tendineae extended from the free edge of the parietal cusp of the right atrioventricular valve to the ventricular free wall. While the discovery of these atypical tendineae provides additional information on canine cardiac anatomy, their presence may also be clinically significant. A review of the veterinary and biomedical literature showed entanglement in normal chordae tendineae can be a complication during cardiac catheterization or pacemaker lead placement. Given this issue with normal chordae tendineae, it seems logical to propose that these atypical tendineae could also cause catheter or pacemaker lead entanglement and therefore warrant further study and documentation.

Porcine Tricuspid Valve Anatomy and Human Compatibility: Relevance for Preclinical Validation of Novel Valve Interventions.

BACKGROUND: Tricuspid regurgitation may be a precursor for heart failure, reduced functional capacity, and poor survival. A human compatible experimental model is required to understand the pathophysiology of the tricuspid valve disease as a basis for validating novel tricuspid valve interventions before clinical use. The study aim was to evaluate and compare the tricuspid valve anatomy of porcine and human hearts. METHODS: The anatomy of the tricuspid valve and the surrounding structures that affect the valve during a cardiac cycle were examined in detail in 100 fresh and 19 formalin-fixed porcine hearts obtained from Danish Landrace pigs (body weight 80 kg). All valvular dimensions were compared with human data acquired from literature sources. RESULTS: No difference was seen in the tricuspid annulus circumference between porcine and human hearts (13.0 ± 1.2 cm versus 13.5 ± 1.5 cm; p = NS), or in valve area (5.7 ± 1.6 cm2 versus 5.6 ± 1.0 cm2; p = NS). The majority of chordae types exhibited a larger chordal length and thickness in human hearts compared to porcine hearts. In both species, the anterior papillary muscle (PM) was larger than other PMs in the right ventricle, but muscle length varied greatly (range: 5.2-40.3 mm) and was significantly different in pigs and in humans (12.2 ± 3.2 mm versus 19.2 mm; p <0.001). CONCLUSIONS: The porcine tricuspid valve was determined to be a valid model for preclinical animal studies, despite various anatomic differences being noted between porcine and human hearts.

Incidence, Distribution and Morphology of Left Ventricular False Tendons in Cat Hearts.

The incidence, distribution, and macro- and microscopic structures of left ventricular false tendons (LVFTs) in the cat heart were studied using 25 normal and 57 diseased hearts. The fibrous bands were observed in the left ventricle of all 82 cat hearts examined and most commonly extended between the papillary muscles and the ventricular septum. Histologically, the LVFTs were composed of central Purkinje fibres and surrounding dense collagenous fibres covered by endothelium. There was no appreciable difference in the incidence, distribution or morphology of LVFTs between the normal and the diseased hearts, indicating that LVFTs are a common anatomic variant in the cat heart.

Morphometry and aberrant morphology of the adult human tricuspid valve leaflets.

The tricuspid valve complex has been studied since the beginning of the twentieth century, and variations in the structural orientation of the tricuspid leaflets has been reported before, as the occurrence of accessory leaflets poses a major problem during surgeries related to the tricuspid valve. In this study, 36 adult formalin-fixed human hearts were analyzed to compare the number, form and size of the tricuspid leaflets. The result shows that in right ventricles, the number of leaflets can vary from the routine three to as many as seven, and the localization of such accessory leaflets of the tricuspid valve differs between specimens. Five leaflet forms were the most common, and the 'typical' form of tricuspid valves with no accessory leaflets was only present in a small percentage of the cases studied. Measurements of the main and accessory leaflets showed that the anterior leaflets were the largest, followed by the inferior leaflets, while the septal and the accessory leaflets were the smallest in size. On the basis of these results, it is suggested that three leaflets of the tricuspid valve are relatively uncommon, with frequent occurrences of accessory leaflets. The multicuspidal form of the tricuspid valve therefore raises concern about understanding the functional and physiological significance of the accessory leaflets.

Percutaneous Transcatheter Mitral Valve Replacement: Patient-specific Three-dimensional Computer-based Heart Model and Prototyping.

Mitral regurgitation is the most prevalent valvular heart disease worldwide. Despite the widespread availability of curative surgical intervention, a considerable proportion of patients with severe mitral regurgitation are not referred for treatment, largely due to the presence of left ventricular dysfunction, advanced age, and comorbid illnesses. Transcatheter mitral valve replacement is a promising therapeutic alternative to traditional surgical valve replacement. The complex anatomical and pathophysiological nature of the mitral valvular complex, however, presents significant challenges to the successful design and implementation of novel transcatheter mitral replacement devices. Patient-specific 3-dimensional computer-based models enable accurate assessment of the mitral valve anatomy and preprocedural simulations for transcatheter therapies. Such information may help refine the design features of novel transcatheter mitral devices and enhance procedural planning. Herein, we describe a novel medical image-based processing tool that facilitates accurate, noninvasive assessment of the mitral valvular complex, by creating precise three-dimensional heart models. The 3-dimensional computer reconstructions are then converted to a physical model using 3-dimensional printing technology, thereby enabling patient-specific assessment of the interaction between device and patient. It may provide new opportunities for a better understanding of the mitral anatomy-pathophysiology-device interaction, which is of critical importance for the advancement of transcatheter mitral valve replacement.

Histomorfometria do epitélio ruminal de cabritos 1/2 sangue Boer submetidos a dietas com tortas oriundas da produção do biodiesel / Histomorphometrics of the ruminal epithelium of 1/2 blood Bôer goats submitted to diets with pies from the production of biodiesel

Objetivou-se determinar o melhor nível de inclusão e de substituição das tortas de dendê e amendoim, respectivamente, em dietas para cabritos 1/2 sangue Boer, por meio da avaliação histomorfométrica das papilas ruminais. Foram utilizados 40 cabritos 1/2 sangue Boer, para cada período experimental, machos, não castrados, com idade aproximada de três meses e com peso inicial de 15,01±1,76kg. Os períodos experimentais constaram de 75 dias e 72 dias. As dietas consistiram de volumoso feno de Tifton-85 e de ração em mistura completa, contendo níveis de inclusão da torta de dendê nas proporções de 0,0; 7,0; 14,0; e 21,0% com base na matéria seca; e de mistura completa, contendo níveis de substituição do farelo de soja pela torta de amendoim nas proporções de 0,0; 33,0; 66,0; e 100%, constituindo-se os tratamentos. No epitélio do rúmen, foram avaliadas altura e largura das papilas, assim como densidade papilar e espessura da parede muscular do rúmen. Entre estas, a altura das papilas, no experimento com torta de amendoim, foi a única a sofrer efeito linear decrescente (P<0,0014); as demais variáveis, tanto dos animais alimentados com torta de amendoim quanto daqueles alimentados com torta de dendê, não foram afetadas pela dieta. As médias de altura encontradas foram de 2,6 e 2,3mm para as tortas de amendoim e dendê, respectivamente. Portanto, a inclusão de até 21% de torta de dendê e a substituição de 100% de torta de amendoim no concentrado de cabritos não alteraram a morfometria das papilas ruminais.

The aim of this study was to determine the best level of pies and replacement of palm oil and peanut, respectively, in diets of 1/2 blood Bôer goats from the histomorphometry of the rumen papillae. A total of 40 1/2 blood male, unneutered, aged approximately three months and initial weight of 15.01±1.76kg Bôer goats were used in each experimental period. The experimental periods consisted of 75 days and 72 days. The diets consisted of roughage hay Tifton-85 and total mixed ration containing levels of inclusion of palm kernel cake in the proportions of 0.0, 7.0, 14.0 and 21.0% based on dry matter; and the second experiment consisted of a complete mixture containing substitution levels of soybean meal by groundnut cake in the proportions of 0.0, 33.0, 66.0 and 100%. Epithelial cells were evaluated in the rumen height and width of the papillae, and density and thickness of the papillary muscle of the rumen. Among these, the height of the papillae in the experiment with peanut butter pie was the only one to suffer a negative linear effect (P<0.0014), the other variables, both in animals fed groundnut cake and palm oil, were not affected by the diet. The average heights found were 2.6 and 2.3, for pies, peanut and palm oil, respectively. Therefore, the inclusion of up to 21% palm kernel cake and replacement of 100% peanut cake in the concentrate of kids did not alter the morphology of the rumen papillae.

Length of papillary muscles in both ventricles of different age group on Bangladeshi cadaver.

Papillary muscle rupture and dysfunction can lead to complications of prolapsed atrioventricular valve and valvular regurgitation. Morphology, measurements and attachments of papillary muscles in both tricuspid and bicuspid valve gains utmost importance in cardiac surgeries and variations in the papillary muscle morphology is one of causes for myocardial infarction in recent time. Therefore, it is important to know both the normal anatomy and variations of papillary muscles. The study was carried out in the department of Anatomy, Mymensingh Medical College, Mymensingh from July 2013 to June 2014. A total 80 human hearts were collected by purposive sampling method, among them 49 were male and 31 were female. The specimens were collected from Bangladeshi cadavers of age ranging from 6 months to 60 years, from autopsy laboratory of the Department of Forensic Medicine of Mymensingh Medical College. All the specimens were grouped into three categories Group A (upto 20 years), Group B (21 to 40 years) and Group C (41 to 60 years) according to age. Dissection was performed according to standard autopsy techniques. Length of each papillary muscle was measured in both ventricles in different age groups. In present study the mean length of the anterior papillary muscles of right ventricle was higher than both the posterior and septal papillary muscles among the age groups. The mean±SD length of the anterior papillary muscle was 1.07±0.48, 1.50±0.37 and 1.60±0.25cm in Group A, B and C respectively. The mean±SD length of the posterior papillary muscle was 1.02±0.35, 1.31±0.40 and 1.37±0.34cm in Group A, B & C respectively. The mean±SD length of the septal papillary muscle in right ventricle was 0.51±0.42, 0.65±0.31 and 0.81±0.35cm in Group A, B & C respectively. It was also observed that the mean length of anterior, posterior and septal papillary muscle was increased with age. In present study the mean length of the anterior papillary muscles in left ventricle was higher than that of the posterior papillary muscle among the age groups. The mean±SD length of the anterior papillary muscle was 1.53±0.34, 2.05±0.39 and 2.01±0.25cm in Group A, B and C respectively. The mean±SD length of the posterior papillary muscle was 1.33±0.34, 1.95±0.89 and 1.81±0.76cm in Group A, B and C respectively and it was also observed that the mean length of both anterior and posterior papillary muscle was increased with age. In statistical analysis, differences between age groups were calculated by using one way ANOVA test.

Automatic segmentation of the left ventricle into 17 anatomical regions in cardiac MR imaging.

Analysis and characterization of anatomical segments in the left ventricle (LV) of the heart in cardiac MRI convey clinical significance. Based on the standard defined by the American Heart Association (AHA), the LV is divided into 17 anatomical segments. In this paper, we propose a novel method to automatically partition the LV into 17 segments, which allows automated analysis of these segments. Our method starts with assigning each slice with a section tag by using the papillary muscles and the LV cavity as references: basal, mid-cavity, apical and apex. It then partitions each slice into 4 or 6 segments by extracting the relevant points on the outer circle of a fitted cylinder and identifying the image orientation by using the lung as a reference. We evaluate our method on 45 patients with different cardiac conditions. The partition of mid-cavity has the best agreement with the ground truth, followed by basal and then apical sections for all groups of patients.