The pathology of mitral valve prolapse

Area of Science:

• Cardiology
• Pathology
• Echocardiography

Background:

• Mitral valve prolapse (MVP) is a common cardiac condition characterized by the displacement of one or both mitral valve leaflets into the left atrium during systole.
• Understanding the morphological and pathological features of MVP is crucial for diagnosing and managing associated complications, particularly mitral regurgitation.

Purpose of the Study:

• To delineate the gross and microscopic diagnostic criteria for mitral valve prolapse.
• To compare morphologic measurements of prolapsed mitral valves with control specimens.
• To identify factors contributing to mitral regurgitation in patients with MVP.

Main Methods:

• Gross examination of surgically removed mitral valves, focusing on leaflet morphology, annular dimensions, and chordae tendineae.
• Microscopic analysis including histochemical and ultrastructural evaluation of valve tissue.
• Comparison of echocardiographic measurements with morphologic findings.

Main Results:

• Key diagnostic features include leaflet hooding, elongation, and annular dilatation, with the posterior leaflet most frequently affected.
• Surgically removed prolapsed valves showed larger leaflet length and annular diameter compared to controls; echocardiography correlated well with leaflet length but underestimated annular diameter.
• Annular ring dilatation and chordae tendineae rupture are significant contributors to mitral regurgitation in MVP patients.

Conclusions:

• MVP exhibits distinct gross and microscopic pathological changes that aid in diagnosis.
• Mitral regurgitation is the most common complication, often linked to annular dilatation and chordal rupture.
• Certain patient subgroups, including those with redundant leaflets or specific ECG findings, may face increased risks of sudden death or infective endocarditis.