Mitral valve stenosis: The effect of other valve problems on diagnosis and treatment
Mitral valve stenosis can occur with other heart valve problems. When this happens, diagnosis can be difficult, and treatment options may be less clear.
Multiple valve problems are generally caused by rheumatic fever, although Marfan's syndrome, other connective tissue disorders, and infective endocarditis can also be causes. Most problems occur with the aortic valve (both stenosis and regurgitation), although there can be problems with the tricuspid or pulmonic valve. Malfunctions of the latter two valves typically happen as a result of earlier problems with the mitral valve, which in turn cause expansion of the base of the pulmonic and tricuspid valves, stretching them out of shape.
Mitral valve stenosis and aortic valve regurgitation
Some people with mitral valve stenosis also have aortic valve regurgitation. In aortic valve regurgitation, the aortic valve leaks, allowing some blood to flow back into the left ventricle after it leaves the chamber. Most of the time this aortic valve regurgitation is of little or no importance.
Having aortic and mitral valve stenosis together can make diagnosis difficult because each can mask the symptoms of the other. Aortic valve regurgitation is usually recognized by a wide pulse pressure (the systolic pressure is much higher than diastolic pressure) and an enlarged left ventricle. But mitral valve stenosis can cause the wide pulse pressure to be absent. Mitral valve stenosis is usually suspected through a heart murmur, but aortic valve regurgitation can cause a similar sound that can either hide the mitral valve stenosis or cause aortic valve regurgitation alone to be diagnosed as mitral valve stenosis and aortic valve regurgitation.
Whichever valve problem is masking the other is considered the dominant valve malfunction, and treatment will be dictated by the treatment guidelines for that valve malfunction.
Mitral valve stenosis and aortic valve stenosis
The combination of mitral valve stenosis and aortic valve stenosis (AS) is serious and can be particularly dangerous when the mitral valve stenosis is treated surgically and the AS is not. When the two conditions occur together, mitral valve stenosis often obscures the AS, making diagnosis of the AS difficult. To confuse the issue further, the combination of mitral valve stenosis and AS can alleviate some of the problems caused by aortic valve stenosis.
For instance, mitral valve stenosis and AS will reduce the pressure gradient and the force at which the left ventricle pumps. This will reduce the rate at which the aortic valve calcifies and the left ventricle muscle enlarges (hypertrophy). It will probably also reduce any angina (chest pain) that occurs because of AS.
Unfortunately, the combination of mitral valve stenosis and AS also tends to exacerbate the problems caused by the mitral valve stenosis. The blood pressure in the lungs (pulmonary hypertension) is elevated, resulting in more congestion buildup in the lungs and hemoptysis (coughing up blood due to blood vessel rupture). Atrial fibrillation also occurs more frequently, as the stress of the two valve malfunctions stretches out the left atrium. As incidences of atrial fibrillation happen more frequently and the atrium stretches, the harder it is to induce the heart to start beating normally again. More frequent atrial fibrillation leads to a greater risk of blood clots developing in your heart and to a greater risk of stroke.
Combined mitral valve stenosis and AS should be recognized before treatment begins. If you fix your mitral valve and not your aortic valve, your heart will suddenly be confronted with compensating for aortic valve stenosis. Since it has not had time to develop these compensations, your heart may suddenly begin to fail. Typically this can lead to acute swelling in your lungs (pulmonary edema), which can be fatal.
How does treatment for other valve problems affect mitral valve stenosis treatment?
A problem with the aortic valve will limit the treatment options for mitral valve stenosis. Because the only way to treat aortic valve malfunctions is through valve replacement surgery, it follows that other valve problems occurring with aortic valve problems will also be treated surgically. But when you replace more than one valve during surgery, you are at increased risk for a shorter life span.
The cause of the mitral valve malfunction can become important in deciding treatment. It may be possible to repair the mitral valve, which is preferable to replacing both valves. Unfortunately, though, it is sometimes impossible to determine either through echocardiograms or angiography whether the mitral valve can be repaired or must be replaced. Often the decision to repair or replace is made during the surgery itself.
Because multiple valve replacement surgery carries a greater risk of death than single valve replacement, the doctor will usually recommend waiting as long as possible before having multiple valve replacement surgery. Unfortunately, replacing both the aortic and mitral valves carries the highest risk of all of the multiple valve replacement combinations. This reinforces the importance of repairing rather than replacing the mitral valve if at all possible.
| Author: | Robin Parks, MS | Last Updated: March 18, 2008 |
| Medical Review: | E. Gregory Thompson, MD - Internal Medicine Stephen Fort, MD, MRCP, FRCPC - Interventional Cardiology | |
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