- Clinical science
Mitral valve prolapse (MVP) is caused by a structural defect of the mitral valve that results in /mitral leaflets bulging into the left atrium during systole. In the US, MVP is the most common heart valve abnormality and the most common cause of mitral regurgitation (MR). Although MVP is typically asymptomatic, symptoms (eg., palpitations, fatigue, dyspnea) may arise, especially if associated with MR. A mitral prolapse click is a classic auscultatory finding MVP and diagnosis is made with echocardiography. No specific treatment is needed unless severe, symptomatic MR is present, in which case mitral valve repair or replacement is required.
- The most common underlying pathology in the case of mitral valve prolapse is myxomatous degeneration → deposition of glycosaminoglycans (e.g., dermatan sulfate).
Mitral valve prolapse sets into motion a vicious cycle of events.
- If prolapse happens without the rupture of chordae tendineae → mitral valve leaflets billow into the left atrium → mild to moderate mitral regurgitation
- If the papillary muscles become severely ischemic and the chordae tendineae rupture → mitral valve leaflets flail about in the left atrium → severe mitral regurgitation
- Most patients are asymptomatic.
- Rarely: atypical chest pain and anxiety
- In case of complications: fatigue, dyspnea, syncope, and palpitations (see “Complications” below)
- Auscultatory findings
- Mitral valve prolapse click: high-frequency, midsystolic click that is best heard at the mitral region
- High-frequency, mid-to-late systolic murmur that is best heard at the mitral region and may radiate to the axilla (squatting diminishes the murmur)
- Patients with severe MR: S3 may be heard as a result of left ventricular overload (especially in the left decubitus position)
- ECG: mostly normal
- Transthoracic echocardiography (test of choice) to confirm diagnosis
- Transesophageal echocardiography (TEE) is used as an adjunct to TTE and intraoperatively to guide mitral valve repair procedures.
- Ventricular ectopics : MVP patients with ventricular ectopics should be asked to avoid caffeine; β-blockers may be used for symptomatic relief.
- Transient ischemic attacks ( ) and/or : Patients who experience TIA or stroke will require prophylactic doses of aspirin (also see “Therapy” in )
- : MVP patients with a past history of infective endocarditis require prophylaxis against infective endocarditis (see ).
We list the most important complications. The selection is not exhaustive.