Mitral valve regurgitation is also known as mitral regurgitation/Mitral Insufficiency. Mitral regurgitation (MR) can occur due to abnormalities of the valve leaflets, the annulus, the chordae tendineae or papillary muscles, or the left ventricle. The most frequent causes of mitral regurgitation are degenerative (myxomatous) disease, ischemic heart disease, rheumatic heart disease, and infectious endocarditis.
Mitral regurgitation is also seen in diseases of the myocardium (dilated and hypertrophic cardiomyopathy), rheumatic autoimmune diseases, e.g. systemic lupus erythematosus, collagen diseases, e.g. Marfan’s and Ehlers–Danlos syndromes, and drugs including centrally acting appetite suppressants (fenfluramine) and dopamine agonists (cabergoline).
Signs and Symptoms
In acute mitral regurgitation, the LA size is not large, and LA pressure rises abruptly, leading to pulmonary edema if severe. When chronic, the LA enlarges progressively and the increased volume can be handled without a major rise in the LA pressure; the pressure in pulmonary veins and capillaries may rise only transiently during exertion. Exertional dyspnea and fatigue progress gradually over many years.
Mitral Regurgitation vs Mitral Stenosis:
Mitral regurgitation leads to chronic LA and LV enlargement and may result in subsequent atrial fibrillation and LV dysfunction. Clinically, mitral regurgitation is characterized by a pansystolic murmur maximal at the apex, radiating to the axilla and occasionally to the base; a hyperdynamic LV impulse and a brisk carotid upstroke; and a prominent third heart sound due to the increased volume returning to the LV in early diastole. The mitral regurgitation murmur due to mitral valve prolapse tends to radiate anteriorly in the presence of posterior leaflet prolapse and posteriorly when the prolapsed is primarily of the anterior leaflet.