Mitral regurgitation or mitral insufficiency is a condition in which the mitral valve does not close completely, so it allows blood to flow backward from the left ventricle into the left atrium.
A very mild degree of mitral regurgitation may be found by color Doppler echocardiogram in almost half of the normal population. If the mitral valve looks structurally normal by two-dimensional echocardiogram then there is nothing to worry about.
Patients with mitral valve prolapse may also develop mitral regurgitation, which usually requires cardiology follow up a few years later to be sure that there is no progressive leakage.
Patients with mild mitral regurgitation do quite well. In cases of more severe mitral regurgitation, the left heart may grow larger as it needs to accommodate a larger volume of blood, and the patient may eventually become fatigue or weak.
Mitral valve regurgitation may be congenital (present at birth) or acquired.
The mitral valve apparatus consists of the mitral valve and a set of strings (chordae tendineae) and two papillary muscles attached to the left heart inner wall. An abnormality in any of the components of the mitral valve apparatus may produce leakage. For example, a cleft (hole) in the mitral valve itself may cause significant leakage. A set of shortened strings can prevent the valve from closing all the way and may allow blood to leak back into the left atrium. Mitral valve prolapse may prevent the valve to seal completely as it closes unevenly. Mitral valve prolapse is virtually an isolated finding, but it may also be found in patients with Marfan syndrome. Mitral regurgitation may also be associated with rheumatic fever, rheumatic heart disease, Kawasaki disease, myocarditis (inflammation of the heart muscle), endocarditis, cardiomyopathy, rheumatoid arthritis, lupus, and other collagenous diseases.
Diagnosis and Cardiovascular Tests:
Mitral regurgitation may be identified during routine color Doppler echocardiogram. In virtually all of those cases with very mild leakage, the finding is not significant. The patients may be referred to us in case of a blowing and pansystolic heart murmur.
In milder forms of mitral regurgitation, the electrocardiogram and chest x-ray may be completely normal. The echocardiogram is very useful, as it will help classify mitral regurgitation into mild-moderate or severe leakage. An echo also helps determine the size of the left heart as well as its function (contractility). In many instances, it may also help determine the possible etiology (cause) of the leakage. It also helps to determine the timing of surgery in those cases with moderate severe mitral regurgitation.
Children with mild to moderate regurgitation usually do not develop any symptoms and lead a normal life. Children with more severe leakage may experience symptoms such as:
Shortness of breath
Difficulty breathing, especially during exertion
Fast heart rate
Patients with a milder form of mitral regurgitation will not require any treatment. Those patients with moderate-severe leakage may require medications such as diuretics (water pills) and drugs that help reduce the workload and improve left heart function. Patients with moderate severe mitral regurgitation should be followed longitudinally with serial echocardiograms. Timing of surgery depends on heart function and/or progressive increase in left heart size. Other factors to consider for the timing of surgery are symptoms, arrhythmias, pulmonary pressures, age of patient, and structural abnormalities in which surgery may be helpful in preventing too much leakage.
There are different types of surgeries such as mitral valve repair, valvuloplasty, valve replacement (mechanical, human, or animal heart valve), and others. In addition, some centers nowadays are offering less invasive procedures that can be performed in the cardiac catheterization laboratory.
Athletes with mild to moderate mitral regurgitation who are in normal heart rhythm, with normal left heart size and function and with normal pulmonary artery pressures can participate in all competitive sports. Most patients with mitral regurgitation lead a normal life. They have a higher incidence of fast heartbeats (tachyarrhythmias) and endocarditis. Optimal dental hygiene and routine dental appointments are recommended in these patients.