Mitral Valve Prolapse

What is mitral valve prolapse?

Mitral valve prolapse is an abnormality of the mitral valve(1) that is usually quite mild. The mitral valve is located between the left upper chamber of the heart (called the left atrium) and the left lower chamber of the heart (called the left ventricle). The mitral valve is one of four valves within the heart and is comprised of two thin flaps of tissue anchored in a firm ring of tissue. The valve leaflets open (2) allowing blood to flow from the left atrium to the left ventricle and close (3) when the filling is complete.

Mitral valve prolapse is diagnosed when there is a backward bowing of the valve leaflets into the left atrium as the ventricle contracts (4). The valve leaflets are often thicker than normal and sometimes there is leakage of the mitral valve but this is usually mild.

A recent and carefully done study suggests that mitral valve prolapse is not as common as previously reported and probably occurs in 2-3% of the population (Freed, 1999). This study is also reassuring in that very few people have any short or long term problems as a result of mitral valve prolapse. Problems during childhood are extremely rare. There are rare cases of sudden cardiac death attributed to mitral valve prolapse but most of these patients had severe leakage of the mitral valve as well. Mitral valve prolapse is associated with connective tissue disorder such as Marfan syndrome. It can be inherited from the child's parents.

What are the effects of this problem on my child's health?

Usually this is a benign finding that has minimal or no short or long term effects on health. Rarely, MVP is associated with abnormal heart rhythms such as atrial fibrillation and ventricular tachycardia. Patients whose mitral valve leaks (a condition called mitral valve regurgitation) are at increased risk for bacterial endocarditis, which is a bacterial infection of the lining of the heart. For the most part, taking a dose of antibiotics prior to dental work and some other medical procedures can prevent this. This use of antibiotics is called SBE prophylaxis.

Exercise recommendations: Exercise recommendations are best made by a patient's doctor so that all relevant factors can be included in the decision. Most patients with mitral valve prolapse do not require any limitations on their physical activities. Limitation from competitive athletics is recommended for patients with serious arrhythmias, severe mitral leakage, Marfan's syndrome (or other connective tissue diseases), or symptoms made worse with exercise such as chest pain or fainting.

How is this problem diagnosed?

Clinical features: MVP is usually diagnosed in adolescence or adulthood. Some reports suggest that it is more common in females than males. There are usually minimal or no symptoms related to mitral valve prolapse. Growth and development are not affected. Some people with mitral valve prolapse experience chest pain and/or palpitations but these sensations rarely represent a serious problem. Mitral valve leakage sometimes progresses over time.

Physical signs: Mitral valve prolapse is usually diagnosed because of the presence of an extra heart sound called a "click". The click may be intermittent. A heart murmur will be heard if the mitral valve leaks.

Medical tests: While there can be false positives and false negative, the diagnosis of mitral valve prolapse can usually be made by echocardiogram. The chest xray is usually normal, as is the electrocardiogram. If there are intermittent symptoms of chest pain, palpitations, or fainting transtelephonic electrocardiograms, treadmill exercise testing, and/or Holter monitoring may be useful.

How is the problem treated?

As described previously, most people experience minimal or no symptoms related to MVP. If there is leakage of the mitral valve, SBE prophylaxis is needed. Rarely, arrhythmias develop that require monitoring and/or treatment. If the mitral valve leakage is severe, mitral valve surgery may be needed.

Clinics

Care and services for patients with this problem are provided in the Congenital Heart and Cardiovascular Surgery clinics at the University of Michigan Medical Center in Ann Arbor.

What is the outlook for children with this problem?
The outlook for people with MVP is excellent for the reasons described above.

References

Freed LA et al. Prevalence and clinical outcome of mitral valve prolapse, N Eng J Med, 341, 1999, 1-6.

Grifka RG & Vincent JA. Abnormalities of the left atrium and mitral valve, including mitral valve prolapse. In Garson A, Bricker JT, McNamara DG (Eds): The Science and Practice of Pediatric Cardiology, Vol ??, Philadelphia PA: Lea & Febiger, 1990. 1277-1298.

Park MK. Valvular heart disease. In Pediatric Cardiology for Practitioners, Chicago, IL: Year Book Medical Publishers, 1988, 252-254.

Rowland TW. Congenital obstructive and valvular heart disease. In B Goldberg (Ed) Sports and exercise for children with chronic health conditions. Champaign IL: Human Kinetics 1995, 233-234.

Written by: S. LeRoy RN, MSN

Reviewed September, 2012