ABSTRACT
Septal papillary muscles, similarly to other papillary muscles, are essential elements of the heart valvular system. Damage to their structure may lead to a considerable life risk. Of all the papillary muscles, the septal papillary muscles are characterized by the greatest topographical and morphological variability. However, information about these muscles is scarce and fragmentary. The objective of this study was to ascertain their occurrence and the region in which they are placed in the inter-ventricular septum. One hundred and eleven human hearts were examined. The hearts belonged to the Clinical Anatomy Department of the Medical University of Gdansk. They were fixed in formalin with ethanol and came from middle-aged and older individuals of both sexes, devoid of pathological changes and birth defects. During the tests, classic anatomical methods were applied. The region where the papillary muscles are found covers a sizeable surface of the septum, from the conus arteriosus up to the back angle of the right chamber. Depending on their location the following septal papillary muscles (musculi papillares septales, MPS) were singled out: 1) lying on the front wall of the septum (anterior papillares septales), 2) in the central part of the septum (central muscles), and 3) in the posterior section of the septum (posterior papillares septales). A trial to determine the types of MPS was based on this diversity of location. Consequently, five types of MPS were specified: type I: anterior-central (44.1%); type II: anterior (15.3%); type III: anterior-posterior (13.5%); type IV: anterior-central-posterior (24.3%); and type V: uniform (2.75%). This study is an attempt to systematize and standardize the terminology of these structures.
