Mitral Valve: Anatomy, Function, and Clinical Relevance

The mitral valve (bicuspid valve) regulates blood flow between the left atrium and left ventricle.

Anatomy

• Two leaflets: anterior (aortic) and posterior (mural).
• Chordae tendineae connect leaflets to papillary muscles (anterolateral, posteromedial).
• Annulus: fibrous ring providing structural support.

Function

• Diastole: Valve opens → blood flows from LA to LV (passive filling + atrial kick).
• Systole: Valve closes → prevents backflow into LA; LV ejects blood via aortic valve.

Common Pathologies

• Mitral Regurgitation: Leaflets don't coapt fully → backward leak. Causes: prolapse, rheumatic, ischemic, cardiomyopathy.
• Mitral Stenosis: Narrowed orifice → impaired filling. Mostly rheumatic.
• Mitral Valve Prolapse: Leaflets billow into LA; often benign, can progress to regurgitation.

Diagnosis: Echocardiography (transthoracic/transesophageal). Treatment: surveillance, medication, repair/replacement (surgical or transcatheter).