MITRAL VALVE PROLAPSE

Mitral Valve connects the left atrium with the left ventricle. The mitral valve apparatus (or device), often called simply the mitral valve, consists of two leaflets, the papillary muscles, and the tendon chordae. The leaflets open during the diastolic phase of the heart cycle and then close tightly.

If during the coaptation of the mitral valve leaflets one or both “get into” in the left atrium during the contraction for more than 2 mm this condition is called Mitral Valve Prolapse. This condition is observed in about 2.5% of the general population. It occurs with equal frequency in women and men, contrary to what was formerly believed.

Mitral valve prolapse had previously been associated with various situations but newer evidence shows this is not valid. Lone mitral regurgitation is usually asymptomatic and is diagnosed at a random examination. When symptoms are present they are associated with concomitant mitral regurgitation. We used to believe that mitral regurgitation is associated with increased arrhythmia burden or transient vascular strokes, which is also not confirmed.

Mitral regurgitation is divided into primary and secondary. Primary mitral regurgitation is further classified into:

a) Mitral Prolapse Syndrome: found in women 20-50 years old, is characterized by thin leaflets with mild prolapse may be accompanied by low blood pressure, orthostatic hypotension and palpitations. It is most of the times benign.

b) Myxomatous Degeneration (Barlowsyndrome): diagnosed in men 40-70 years, characterized by thickening of the leaflets, severe prolapse and increased chance of mitral regurgitation – which will gradually worsen and require surgery.

Secondary mitral regurgitation is related with a disproportion of the dimensions of the mitral annulus and left ventricle. It is usually observed in young women and is resolved with advanced age. In most of the cases it is not accompanied by valve regurgitation. Secondary prolapse may also be present in connective tissue diseases (90% in Marfan syndrome, >6% on Ehler-Danlos syndrome), in incomplete osteogenesis etc. It can be present in atrial fibrillation, hyperthyroidism, emphysema, obstructive hypertrophic cardiomyopathy. Secondary mitral valve prolapse is usually of little clinical significance and is not associated with severe mitral regurgitation.

Mitral valve prolapse does not require special treatment. Any treatment is related to mitral regurgitation when it exists. Diagnosis is established via echocardiography. The current guidelines recommend a follow-up every 3 to 5 years.

Current guidelines (2015, European Society of Cardiology) classify mitral regurgitation as an intermediate risk for infective endocarditis and advise against the administration of chemoprophylaxis (preventive antibiotic treatment) in routine dental procedures.

In patients with mitral valve prolapse, especially primary, it is recommended to avoid situations such as abrupt weight lifting.