Mitral Valve Regurgitation - Cause
two forms of mitral valve regurgitation (MR): chronic
and acute. Chronic mitral valve regurgitation develops slowly over several
years. Acute MR develops suddenly.
Chronic mitral valve regurgitation
valve regurgitation is caused by diseases or conditions that damage the mitral
valve over time. The valve then allows blood to leak backward
The mitral valve may become hard, or calcified,
around the tough ring of tissue (annulus) to which the mitral valve flaps are
attached. Normally the mitral annulus is soft and flexible. But as a person
ages, calcium may build up inside the annulus. This hardened mitral valve
cannot close completely, and blood leaks backward (regurgitates) into the upper
left chamber of the heart (atrium).
of diseases or conditions that can cause mitral valve regurgitation
- Mitral valve prolapse.
- Heart defects or
abnormalities present at birth (congenital heart defects).
- Endocarditis, which is an infection of
the lining of the heart and heart valves. This infection can scar the mitral
- Injury to the heart or the chordae tendineae, which are
strong, flexible cords that control the opening and closing of the mitral
- Dilation of the
left ventricle, or
heart failure. This can be caused by years of
high blood pressure,
coronary artery disease, or heart muscle disease
- Autoimmune diseases that
can damage the mitral valves, such as
rheumatoid arthritis or
- Marfan's syndrome, which is a connective tissue
- Severe kidney disease.
- Rheumatic fever, which can scar the heart valves and
prevent them from closing completely.
- Previous use of the
weight-loss medicine fen-phen (phentermine and fenfluramine/dexfenfluramine),
which appears to increase the risk of heart valve disease.
Acute mitral valve regurgitation
valve regurgitation occurs when the mitral valve or one of its supporting
structures ruptures suddenly, creating an immediate overload of blood volume
and pressure in the left side of the heart. Your heart
doesn't have time to adjust to the increased volume and pressure of blood (as it does in chronic MR).
Causes of sudden rupture include:
- Injury to the chordae tendineae. Endocarditis may also cause the chordae
tendineae to rupture.
- Injury to the chest.
- Heart attack,
which may cause the rupture of the muscle (papillary) surrounding the valve.
- Problems with a
prosthetic mitral valve.
- Perforation of
the mitral valve flap (leaflet), caused by endocarditis.