Mitral regurgitation

Mitral regurgitation (MR) may present with dyspnoea, usually on exertion, palpitations, and/or decreased exercise tolerance.

Typically presents as a holosystolic blowing murmur at the apex, radiating to the axilla.

Transthoracic echo is the diagnostic test of choice in identifying presence, severity, and mechanism of MR.

Colour Doppler flow and continuous-wave Doppler studies can assess severity of regurgitation, left ventricular dimensions, size and function of the right ventricle, and pulmonary artery systolic pressure.

Management options include surgical repair or replacement and transcatheter mitral valve repair; the risks and benefits of interventional options should be individually evaluated for each patient.

The most common complications of surgical treatment are failure of repair, prosthetic valve stenosis, endocarditis, and mitral valve patient-prosthesis mismatch.

The mitral valve apparatus consists of anterior and posterior leaflets, chordae tendineae, anterolateral and posteromedial papillary muscles, and mitral annulus. Any aberrations of the mitral valve apparatus, due to mechanical, traumatic, infectious, degenerative, congenital, or metabolic causes, may lead to mitral regurgitation (MR).

Mild to moderate disease can be asymptomatic for many years; however, with progression of the disease, eccentric cardiac hypertrophy occurs, which leads to elongation of the myocardial fibres and increased left ventricular end-diastolic volume. Eventually, prolonged volume overload leads to left ventricular dysfunction and increased left ventricular end-systolic diameter.