Mitral valve regurgitation
Mitral valve regurgitation (MR) is the leaking or backflow of blood through the valve between the upper left heart chamber (atrium) and the lower left heart chamber (ventricle). If serious, this condition can lead to a backup of blood in the left atrium and the lungs, cause enlargement of and damage to the left ventricle, and lead to heart failure.
Current as of: May 1, 2026
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