Parachute mitral valve (or PMV) is a rare

congenital heart disease A congenital heart defect (CHD), also known as a congenital heart anomaly and congenital heart disease, is a defect in the structure of the heart or great vessels that is present at birth. A congenital heart defect is classed as a cardiovascular ...

where the

mitral valve The mitral valve (), also known as the bicuspid valve or left atrioventricular valve, is one of the four heart valves. It has two cusps or flaps and lies between the left atrium and the left ventricle of the heart. The heart valves are all one- ...

only has a single papillary muscle from which all

chordae tendineae The chordae tendineae (tendinous cords), colloquially known as the heart strings, are inelastic cords of fibrous connective tissue that connect the papillary muscles to the tricuspid valve and the mitral valve in the heart. Structure The chord ...

originate. It is caused by an embryologic failure of papillary muscles to divide into two normally distinct columns, giving the mitral valve orifice and chordea an irregular, parachute-like appearance. Due to the abnormal anatomy, there are almost always associated mitral valve disorders, and because of its abnormal embryologic origin, PMV almost always coincides in a complex of other congenital heart defects. PMV is usually identified during infancy or childhood due to its symptomatic nature, and hardly ever diagnosed during adulthood.

Clinical significance

Associated Mitral Valve Disease

As a result of the thickened and shortened chordae, there is a restriction of the inflow of blood to mitral valve annulus and subannulus causing a narrowing known as

mitral stenosis Mitral stenosis is a valvular heart disease characterized by the narrowing of the opening of the mitral valve of the heart. It is almost always caused by rheumatic valvular heart disease. Normally, the mitral valve is about 5 cm2 during d ...

which increases the pressure gradient through the valve. Also, abnormal closure of the mitral valve leaflets or

mitral valve prolapse Mitral valve prolapse (MVP) is a valvular heart disease characterized by the displacement of an abnormally thickened mitral valve leaflet into the left atrium during systole. It is the primary form of myxomatous degeneration of the valve. There ...

will cause the valve significantly leak during closure known as

mitral valve insufficiency Mitral regurgitation (MR), also known as mitral insufficiency or mitral incompetence, is a form of valvular heart disease in which the mitral valve is insufficient and does not close properly when the heart pumps out blood.

. Parachute mitral valve is commonly associated with other congenital heart disease. A 2004 study finds that children with PMV are 68% likely to have aortic coarctation, 54% likely to have an atrial septal defect, 46% likely to have a ventricular septal defect, and 19% likely to have left ventricular hypoplasia. Parachute mitral valve is also a part of the congenital complex of

Shone's Syndrome Shone's syndrome is a rare congenital heart defect described by Shone in 1963. In the complete form, four left-sided defects are present: * Supravalvular mitral membrane (SVMM) * Parachute mitral valve * Subaortic stenosis (membranous or muscular) ...

. Unfortunately, the overall outcome of the children diagnosed with parachute mitral valve especially with the other likely multilevel left-heart diseases is only somewhat satisfactory. However, with increasingly improved technology for mitral valve reconstructions, repairs and replacements procedures, outcomes are expected to improve in the future.

References

{{reflist Cardiology Cardiogenetic disorders