Papillarmuskeln

Papillarmuskeln, or papillary muscles, are muscular projections located within the ventricles of the heart. They anchor the chordae tendineae, which connect to the leaflets of the atrioventricular valves (mitral and tricuspid). By contracting during ventricular systole, the papillary muscles tense the chordae and prevent valve leaflets from prolapsing into the atria, helping to prevent regurgitation.

Anatomy and variation: In the left ventricle, there are typically two principal papillary muscles—the anterolateral and the posteromedial. The right ventricle contains several papillary muscles, commonly described as anterior, posterior, and septal. Each muscle gives rise to chordae tendineae that attach to the corresponding valve leaflets. The vascular supply to the papillary muscles varies with coronary dominance: the anterolateral muscle often receives a dual blood supply from branches of the left anterior descending and left circumflex arteries, while the posteromedial muscle is usually supplied by the posterior descending artery and is more susceptible to ischemic injury in single-vessel disease.

Clinical significance: Papillary muscle dysfunction or rupture can occur after myocardial infarction or other cardiac trauma, leading to acute or severe valvular regurgitation, heart failure, and shock. Management may require urgent surgical repair or replacement of the affected valve, along with revascularization and supportive hemodynamic care.

Related structures: The papillary muscles are part of the subvalvular apparatus that includes the chordae tendineae and the valve leaflets, functioning together to ensure proper valve closure during systole.