Positions of septal papillary muscles in human hearts

Area of Science:

• Cardiovascular Anatomy
• Cardiac Morphology
• Human Anatomy

Background:

• Septal papillary muscles (MPS) are crucial for heart valve function, and their damage poses significant risks.
• Existing knowledge on the topography and morphology of MPS is limited and fragmented.
• Understanding MPS variability is essential due to their significant topographical and morphological diversity.

Purpose of the Study:

• To investigate the occurrence and anatomical location of septal papillary muscles (MPS) within the inter-ventricular septum.
• To classify the different types of MPS based on their topographical distribution.
• To contribute to the systematization and standardization of terminology for MPS.

Main Methods:

• Examination of 111 human hearts from the Clinical Anatomy Department, Medical University of Gdańsk.
• Hearts were preserved in formalin with ethanol and sourced from adult individuals without pathological changes or congenital defects.
• Application of classic anatomical methods to identify and categorize MPS based on their location within the septum.

Main Results:

• Septal papillary muscles (MPS) were identified across a broad region of the inter-ventricular septum, from the conus arteriosus to the posterior angle of the right ventricle.
• Three main locations were identified: anterior, central, and posterior.
• Five distinct types of MPS were classified based on location: anterior-central (44.1%), anterior (15.3%), anterior-posterior (13.5%), anterior-central-posterior (24.3%), and uniform (2.75%).

Conclusions:

• This study provides a detailed classification of septal papillary muscles (MPS) based on their anatomical location and frequency.
• The findings highlight the significant variability in MPS morphology and distribution.
• Standardizing MPS terminology is proposed to improve clarity in anatomical and clinical contexts.