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.

A Comparative Study Of Number And Position Of Papillary Muscles And Clinical Significance

Introduction: Papillary muscles are the conical muscle masses project into the cavity of ventricle and areinserted into the valve cusps by chordae tendinae. They prevent the cusps from being forced back into the atriumduring ventricular contraction. Their number and positions are highly variable. An anomalous papillary musclecan act as an ectopic foci. Hence these variations should be assessed before any operative intervention on thevalve. Present study aim to analyse these variations in detail.Materials and Methods: This is a descriptive observational study to analyse the variations in number andposition of papillary muscles in ventricles of 100 adult human hearts ranging in age from 17 to 80 yearsobtained from autopsy specimens. The methodology used was the dissection method according to standardautopsy techniques. The data obtained were quantified as frequencies (in %).Results: Of the 100 hearts studied, the right ventricle consisted of the usual three groups of papillary muscles in84% of hearts whereas the remaining 16% of hearts had only two groups (rudimentary SPMs). The left ventricleconsisted of two groups of papillary muscles in 73% of hearts ; three groups in 23%; four groups in 4% and noneof the hearts contained single papillary muscle. Regarding the positions, the right ventricle had APMs inanterobasal position, the PPMs in posterobasal position and SPMs was located close to ventricular septum andno extra group of papillary muscles were found. In left ventricle, 73% of hearts had APMs and PPMs in anterolateraland posteromedial positions respectively, whereas in 27% (23% and 4%) hearts, the extra group of papillarymuscles (third group and fourth group) were interlinked to PPMs and was situated in posterolateral position.Conclusion: These findings suggest that the variations in number and positions of papillary muscles should beanticipated before any operative intervention on the valvular apparatus.

Morphometric and Clinical Analysis of Moderator Band in Humans.

Background: The moderator band has the right bundle of His within the right ventricle. It also is known to prevent the over dilatation of RV. It is important because of its involvement in RV infarcts, in differentiating RV from LV in congenital anomalies, in VPDs & VTs and in VSDs. The present literature is very much lacking in its morphometry. Materials and Methods: Moderator band was looked for in 50 hearts and only in this study did we find it in all the hearts. The length, the thickness, the distance from the tricuspid valve along with the presence of any trabeculations in the septal end or in the papillary muscle end were looked for and recorded. Results: The average length was 14.71±4.99mm, the average thickness was 4.97±1.64 mm, the average distance from the tricuspid orifice was 19.85±5.92 mm. The attachment to the anterior papillary muscle was found to be branched in 8 hearts that is having an incidence of 14% . The septal end were branched and separated as two in only two specimens. Only one specimen had branched attachments on both the apical and septal ends. Conclusion: The distance from tricuspid valve and knowledge of branching are important in corrective surgeries of the VSDs. An awareness of length and thickness helps the clinician to differentiate moderator band from the other structures, which may result in misdiagnosis during echocardiography. Its presence may in fact be of significance in preventing over distension of the heart in RV myocardial ischaemia.

A Morphological And Morphometric Study Of Right Ventricular Papillary Muscles In North Indian Region.

Abstracts: Background & Objective: Aim of present study was morphological and morphometric observation of papillary muscles of tricuspid valve of human heart. Methodology: This study was carried out in 36 human (24 males and 12 females) heart from adult cadavers, which were dissected according to standard technique. All papillary muscles were observed for their shapes, numbers and dimensions in centimeters. Data were tabulated and statistical comparison were done using “chi square” and “z” test. Results: The average length of anterior, posterior and septal papillary muscle was 1.42 ± 0.29 cm, 0.94 ± 0.23 cm and 0.18 ± 0.08 cm while average breadth of anterior, posterior and septal papillary muscle was 0.41± 0.12 cm, 0.29± 0.09 cm and 0.11± 0.01 cm respectively. The anterior papillary muscles presented 1 head in 27.78% and 2 heads in 25%, while posterior papillary muscles presented 1 head in 27.78% and 2 heads in 25%. All the septal papillary muscles presented with 1 head. Single anterior papillary muscle was found to be 97.22% while posterior papillary muscle was found to be single in 72.28% and double in 27.78. Septal papillary muscle was found to be single in 25% cases and absent in 38.89% cases. Conclusion: Data obtained from this study might be helpful for reparative surgical procedures of tricuspid valve.