Thursday, April 12, 2012

Mitral Valve Proplapse (MVP) Symptoms, Complications and Invesigations

Mitral valve bulging back into the left atrium during systole is called mitral valve prolapse. This is also called floppy mitral valve or or myxomatous mitral valve.

MVP is twice as frequent in women as in men. In the mildest form due to prolapse of mitral valve there is only mid-systolic click but progressively it leads to mitral regurgitation.

MVP exhibits a strong hereditary component and in some patients is transmitted as a autosomal dominant trait.

Etiology
  • Most commonly it develops due to myxomatous degeneration of mitral valve in which middle layer of valve leaflet composed of loose, myxomatous material is unusually prominent.
  • Second common cause in our country is rheumatic fever.
  • MVP may occasionally result from Marfan syndrome, Ehlers-Danlos syndrome, osteogenesis imperfecta, periarteritis nodosa, myotonic dystrophy, von Willebrand disease, hyperthyroidism, Ebstein anomaly of tricuspid valve, hypertrophic cardiomyopathy, ASD II, mitral valve surgery and left ventricular aneurysm.

Clinical Features

Symptoms
  • Most patients with Mitral Valve Proplapse are asymptomatic.
  • In symptomatic patient it presents as chest pain, dyspnea, fatigue, palpitation, syncope and sudden death (reasons of symptoms is unknown). Palpitation may be due to atrial or ventricular premature beats or tachyarrhythmias. Chest pain is similar to angina but may last for hours or days, not related to exertion, and punctuated by brief attacks or severe stabbing pain at apex. This chest pain or discomfort may be due to abnormal tension and papillary muscles.
  • Mitral regurgitation (MR) may develop due to progressive elongation of chordae teninae.
  • Spontaneous rupture of chordae tendinae may cause a sudden worsening of MR that is hemodynamically severe.

On Examination
  • On auscultation there is midsystolic click in mild cases and pansystolic murmur if significant mitral regurgitation. Thoracic deformities are more prevalent in Mitral Valve Proplapse such as loss of normal thoracic kyphosis (straight back syndrome) pectus excavatum and scoliosis.
  • BP may be normal or low.

Complications
  • Infective endocarditis
  • Rupture of chordae tendineae causing sudden severe MR.
  • Progressive MR
  • Arrhythmias and sudden death.

Investigations

ECG may be normal or show arrhythmias such as SVT, atrial or ventricular premature contractions, ventricular tachyarrhythmias, sinus node dysfunction or varying degrees of heart block.

Echocardiography is diagnostic of  Mitral Valve Proplapse (MVP). It shows one or both mitral valve leaflets bulging by at least 2mm into the left atrium during systole. Thickening of the involved leaflet to > 5 mm supports the diagnosis. Doppler echo frequently reveals mild MR that is not always associated with an audible murmur.

Management
  • Asymptomatic patients without arrhythmia on ECG should be reassured about the prognosis and follow up every 3-5 years.
  • Beta-blockers and aspirin