Mitral regurgitation

A retrograde flow of blood from the left ventricle into the left atrium during systole due to incomplete mitral valve closure, resulting in left-sided volume overload and a characteristic systolic murmur maximal at the apex. Possible causes are mitral valve prolapse, infective endocarditis, rheumatic heart disease, connective tissue disorders (Marfan syndrome, Ehlers-Danlos syndrome), and congenital defects.