mitral valve prolapse

Picture a sail that is slightly too large for its mast: under the wind it billows and bulges backward instead of lying flat. In mitral valve prolapse one or both mitral leaflets are floppy and excessive, so during the heart's contraction they balloon back into the left atrium instead of meeting neatly edge to edge.

This billowing produces a characteristic clicking sound, and if the seal is imperfect, a murmur of leakage. Many people with prolapse have a normal lifespan and never develop significant problems; the condition is one of the most common valve findings in the general population, and is frequently discovered incidentally.

The underlying issue is usually a degenerative change in the leaflet tissue (myxomatous degeneration) that makes it redundant and stretchy, sometimes with elongated or ruptured supporting cords. A minority of patients develop progressively severe mitral regurgitation requiring repair, and the floppy leaflets carry a small added risk of certain arrhythmias. Echocardiography confirms the diagnosis and tracks any leak.

Prolapse spans a wide spectrum from a benign incidental finding to a cause of severe regurgitation, so generalizations should not replace individual evaluation.