papillary muscle rupture
Mechanical complication of myocardial infarction involving complete or partial tearing of papillary muscles, causing acute mitral regurgitation.
Full Definition
Papillary muscle rupture represents a catastrophic mechanical complication of acute myocardial infarction, characterized by complete or partial tearing of one or more papillary muscles that anchor the mitral valve leaflets via chordae tendineae. This condition typically occurs 3-7 days post-infarction when the necrotic muscle is most vulnerable before scar formation. The posteromedial papillary muscle is more commonly affected than the anterolateral muscle due to its single blood supply from the posterior descending artery. Rupture results in severe acute mitral regurgitation with rapid hemodynamic deterioration. Pathologically, the diagnosis is confirmed by identifying the torn muscle head and associated hemorrhage, often with evidence of underlying infarction.
Usage
Usage note: Always specify which papillary muscle is affected and whether rupture is complete or partial.
In Context
- "Autopsy revealed complete rupture of the posteromedial papillary muscle with the muscle head floating free in the left ventricle." — Post-infarction autopsy
- "The cause of sudden hemodynamic collapse was determined to be papillary muscle rupture complicating the inferior myocardial infarction." — Emergency cardiac pathology