Mitral valve prolapse

From Ganfyd

Mitral valve prolapse (MVP) is common, often symptomatic and benign

Mitral valve prolapse was originally described as billowing mitral leaflet and the present name was first used in 1966. It has been subsequently recommended^[1] that the term prolapse should be reserved to indicate that the free edge of the leaflet protrudes beyond the mitral annulus level during systole, whereas the term billowing with its different prognosis should be used when the leaflet body bulges into the left atrium, overriding the mitral annulus plane and usually maintaining the free edge of the leaflets on the ventricular side. A mitral valve can be both billowing and prolapsing. The underlying pathology is usually myxomatous degeneration for those coming to surgery. Barlow's syndrome, is a term for the most extreme form of myxomatous degeneration in younger patients with excess leaflet tissue. Older patients tend to have fibroelastic deficiency.

Epidemiology

• Most common heart defect in population, commoner in young women.
• Prevalence about 0.6–2.5%
• Increases with age
• Benign without serious consequences except in older men^[2]
• Common cause of iatrogenic cardiac neurosis
• Associated with X-linked myxomatous valvular dystrophy, Marfans, Ehlers-Danlos syndrome, osteogenesis imperfecta and at least three other genes^[3]

Symptoms

• Mitral valve prolapse symptoms are common despite benign prognosis^[4]. They include:
  • Autonomic dysfunction
  • Palpitations^[5]
  • Orthostatic hypotension and increased risk of vasovagal syncope^[5]
  • Fatigue
  • Atypical chest pain, dyspnoea, anxiety and panic attacks are no more frequent than with other patients with or without physical signs

Signs

• Some will have those of mitral incompetence
• Auscultation for midsystolic clicks and late-systolic murmurs that may be brought typically by manoeuvers such as squatting.

Investigation

ECG

It is associated with benign arrhythmia^[5]. A third will have ventricular arrhythmias, usually ectopics. Ventricular tachycardia is found in less than 2%^[6] and predicted by the presence of moderate to severe mitral regurgitation.

Echocardiography

• Mitral valve prolapse is when there is displacement of mitral valve leaflet(s) above the annulus into the left atrium during systole

Other

• Cardiovascular magnetic resonance imaging can allow tissue characterization such as the myocardial fibrosis involving the papillary muscle associated with those with more exotic causes of the MVP.
• Multislice computed tomography can help work up in those with severe mitral regurgitation prior to surgery
• Blood culture if endocarditis suspected - there is a small increased risk of this complication due to the secondary mitral and tricuspid regurgitation

Management

• Reassurance
• If severe mitral regurgitation or with left ventricular dysfunction (ejection fraction <60%) or with left ventricular dilatation (left ventricular end-systolic dimension >4 cm) surgery should be considered^[7]

References