Papillary muscles of left ventricle

The papillary muscles of the left ventricle are specialized myocardial structures that anchor the chordae tendineae, which in turn attach to the mitral valve leaflets. There are two main papillary muscles: the superior (anterolateral) papillary muscle and the inferior (posteromedial) papillary muscle. The superior papillary muscle is located superolaterally, while the inferior papillary muscle is situated inferoseptally within the left ventricular cavity. These muscles project from the ventricular wall and are covered by endocardium, attaching to the ventricular wall via trabeculae carneae rather than directly to the solid myocardium.

Each papillary muscle gives rise to multiple chordae tendineae, which are classified as primary (to the leaflet edge), secondary (to the body/rough zone), and tertiary (to the base or annulus, typically from the ventricular wall).The superior papillary muscle generally supplies chordae to the lateral half of both the anterior and posterior mitral leaflets, while the inferior papillary muscle supplies the medial half.Morphological studies show significant variability in the number, shape (conical, truncated, bifurcate, trifurcate, etc.), and branching patterns of these muscles and their heads.