Mitral Regurgitation

Mitral regurgitation is a heart condition where the valve between the left atrium and left ventricle does not close properly. This causes blood to flow backward into the atrium when the heart pumps, which can make the heart work harder. The main body system involved is the cardiovascular system, specifically the heart's left side. Over time, this backward flow can lead to symptoms like shortness of breath, fatigue, and irregular heartbeats. If untreated, it may cause heart enlargement and heart failure. The condition can result from valve damage due to infections, aging, or other heart diseases. Understanding this helps explain why the heart's efficiency is reduced in mitral regurgitation.

Mitral regurgitation is defined as the retrograde flow of blood from the left ventricle into the left atrium during systole due to incomplete closure of the mitral valve. The core pathology involves structural abnormalities of the mitral valve apparatus, including the leaflets, chordae tendineae, papillary muscles, or annulus. Common causes include mitral valve prolapse, ischemic heart disease causing papillary muscle dysfunction, rheumatic heart disease, and infective endocarditis. This valvular incompetence leads to volume overload of the left atrium and ventricle, resulting in left atrial dilation, left ventricular hypertrophy, and eventually heart failure if severe and untreated. Clinically, it is significant because it can cause pulmonary congestion, atrial fibrillation, and reduced cardiac output. The severity of regurgitation correlates with symptom burden and prognosis.