Filed under: Heart & Vascular
Mitral valve stenosis — or mitral stenosis — is a condition in which the heart's mitral valve is narrowed (stenotic). This narrowing blocks the valve from opening properly, obstructing blood flow through your heart and from your heart to the rest of your body. Mitral valve stenosis can make you tired and short of breath, among other problems.
The main cause of mitral valve stenosis is a childhood infection called rheumatic fever, which is related to strep infections. Rheumatic fever — once common in the United States and still prevalent in developing countries — can scar the mitral valve.
Mitral valve stenosis in people of all ages is treatable. Left unchecked, mitral valve stenosis can lead to serious heart complications.
©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
You can have mitral valve stenosis and feel well, or you may have only minimal signs and symptoms for decades. However, mild problems can suddenly get worse. See your doctor if you develop these mitral valve stenosis symptoms:
Mitral valve stenosis symptoms — which may resemble those of other heart or heart valve conditions — may appear or worsen anytime you increase your heart rate, such as during exercise. An episode of rapid heartbeats also may accompany these symptoms. Or they may also be triggered by pregnancy or other stress on your body, such as a respiratory infection or heart infection.
Mitral valve stenosis symptoms usually include those of heart failure, a complication of mitral valve stenosis and other heart problems. In mitral valve stenosis, pressure that builds up in the heart is then sent back to the lungs, resulting in fluid buildup (congestion) and shortness of breath.
Symptoms of mitral valve stenosis most often appear in your 40s and 50s, but they can occur at any age — even during infancy. Depending on the amount of narrowing, an infant or a child with mitral valve stenosis may have no symptoms, may tire easily or may have shortness of breath with vigorous physical activity.
Mitral valve stenosis may also produce a number of signs that only your doctor will be able to find. These may include:
When to see a doctor
Call your doctor for an immediate appointment if you develop symptoms such as fatigue or shortness of breath during physical activity, heart palpitations or chest pain.
If you've been diagnosed with mitral valve stenosis but haven't had symptoms, talk to your doctor about recommended follow-up.
©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
The heart, the center of your circulatory system, consists of four chambers. The two upper chambers, the atria, receive blood. The two lower chambers, the ventricles, pump blood.
Blood flows through your heart's chambers, aided by four heart valves. These valves open and close to let blood flow in only one direction through your heart:
The mitral valve — which lies between the two chambers on the left side of your heart — consists of two triangular-shaped flaps of tissue called leaflets. The leaflets of the mitral valve connect to the heart muscle through a ring called the annulus. Anchoring the mitral valve to the left ventricle are tendon-like cords, resembling the strings of a parachute, called chordae tendineae cordis.
Heart valves open like a trapdoor. The mitral valve is forced open when blood flows from the left atrium into the left ventricle. When all of the blood has gone through the valve, the leaflets swing closed to prevent the blood that has just passed into the left ventricle from flowing backward, in the wrong direction.
A defective heart valve is one that fails to either open or close fully. When a valve doesn't close tightly, blood can flow backward. This backward flow through a valve is called regurgitation (insufficiency). When a valve becomes narrowed and blood flow through it is limited, the condition is called stenosis.
Mitral valve stenosis is narrowing of the mitral valve. Many factors can tighten this passageway between the heart's left-sided chambers, obstructing blood flow into the heart's left ventricle. Causes of mitral valve stenosis include:
©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
Mitral valve stenosis is less common today than it was several decades ago because the most common cause, rheumatic fever, has largely been eradicated in the United States. However, rheumatic fever remains a frequent problem in countries where antibiotic use isn't as common.
Risk factors for mitral valve stenosis include a history of rheumatic fever and recurrent strep infections. Radiation treatment involving the chest can result in mitral valve stenosis. Other unusual causes of mitral valve stenosis include medications, such as ergot preparations used for migraines.
©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
Whatever the cause, a narrowed mitral valve limits blood flow in the same way a narrow funnel spout limits the flow of fluid through a funnel. In mitral valve stenosis, blood has a difficult time flowing from the left atrium to the left ventricle. Pressure builds up in the left atrium, and the chamber may enlarge. Blood may back up into your lungs, leading to lung congestion and shortness of breath. In addition, the enlarged left atrium may become prone to a heart rhythm irregularity called atrial fibrillation. In atrial fibrillation, the upper chambers (atria) of the heart beat chaotically and inefficiently.
Like other heart valve problems, mitral valve stenosis can weaken your heart and decrease how efficiently it pumps blood. Mitral valve stenosis reduces the amount of blood that flows forward through your heart and out to the rest of your body.
Left unchecked, mitral valve stenosis can lead to complications such as:
©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
You're likely to start by first seeing your family doctor. After your initial appointment, your doctor may refer you to a doctor who specializes in the diagnosis and treatment of heart conditions (cardiologist).
Here's some information to help you prepare for your appointment.
What you can do
Questions to ask your doctor at your initial appointment include:
Questions to ask if you are referred to a cardiologist include:
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment at any time that you don't understand something.
What to expect from your doctor
A doctor or cardiologist who sees you for possible mitral valve stenosis may ask:
What you can do in the meantime
While you wait for your appointment, check with your family members to find out if any close relatives have been diagnosed with cardiac disease. The symptoms of mitral valve stenosis are similar to a number of other heart conditions, including some that tend to run in families. Knowing as much as possible about your family's health history will help your doctor determine next steps for your diagnosis and treatment.
If exercise makes your symptoms worse, avoid exerting yourself physically until you've been seen by your doctor.
©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
If you develop signs or symptoms of mitral valve stenosis — for example, if you experience sudden breathlessness with mild exertion — your doctor may ask you to undergo several types of diagnostic tests.
But first your doctor will ask about your medical history and give you a physical examination. As part of your examination, he or she listens carefully to your heart through a stethoscope. Mitral valve stenosis causes an abnormal heart sound, called a heart murmur. Normal heart valves open silently to permit the flow of blood. A narrowed mitral valve can make a distinct snapping sound followed by a rumbling murmur.
In addition to listening to your heart, your doctor listens to your lungs and the sounds of your breathing. Your doctor is checking for lung congestion — the buildup of fluid in your lungs — that can occur with mitral valve stenosis.
From the initial information, your doctor decides which tests are needed to make a diagnosis. For testing, you may be referred to a cardiologist.
Diagnostic tests
Common tests to diagnose mitral valve stenosis include:
Cardiac tests such as these help your doctor distinguish mitral valve stenosis from other heart conditions, including other problems of the mitral valve. Mitral regurgitation is a condition in which the mitral valve doesn't close tightly. Mitral valve prolapse is a disorder in which the mitral valve sags instead of closing tightly. These conditions may also require treatment.
If you receive a diagnosis of mitral valve stenosis, these tests also help reveal the cause, determine how serious the problem is, and determine whether the mitral valve can be repaired or if replacement may be necessary.
©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
Treatments to prevent permanent damage to your heart from mitral valve stenosis include medications and invasive procedures.
Invasive treatment for mitral valve stenosis isn't always needed right away. If tests reveal that you have mild to moderate mitral valve stenosis and you have no symptoms, there's generally no need for immediate valve repair or replacement. Instead, your doctor will schedule checkups to carefully monitor the valve so that surgery can be done as soon as your condition becomes severe. Some people never need anything done to the mitral valve because they never develop severe mitral valve stenosis.
Medications
No medications can correct a defect in the mitral valve. However, certain drugs can reduce symptoms by easing your heart's workload and regulating your heart's rhythm.
For example, your doctor may prescribe:
Your doctor may also prescribe drugs to treat atrial fibrillation or other rhythm disturbances associated with mitral valve stenosis.
Procedures
You may need valve repair or replacement to treat mitral valve stenosis. Both surgical and nonsurgical options are available.
Repair with balloon valvuloplasty (valvotomy)
This nonsurgical procedure uses a soft, thin tube (catheter) tipped with a balloon. A doctor guides the catheter through a blood vessel in your arm or groin to your heart and into your narrowed mitral valve. Once in position, a balloon at the tip of the catheter is inflated. The balloon pushes open the mitral valve and stretches the valve opening, improving blood flow. The balloon is then deflated and the catheter with balloon is guided back out of your body. Balloon valvuloplasty can relieve mitral valve stenosis and its symptoms. But it may not be appropriate if the valve is both tight (stenotic) and leaky (regurgitant). It's also not performed if there's a blood clot in a chamber of your heart, because of the risk of dislodging it. You may need the procedure repeated within 10 years.
Mitral valve surgery
If there is more than mild leakage (regurgitation) of your valve or if you have other valve problems in addition to mitral stenosis, surgery may be a better option than balloon valvuloplasty. Surgical options include:
Mitral valve surgery may involve open-heart surgery. However, techniques that use less invasive techniques are increasingly available. For example, in robotic surgery, a surgeon watches a 3-D image of the area being operated on and uses hand controls that tell thin robotic arms how to maneuver surgical tools. This approach uses smaller incisions, and recovery time is faster in most cases.
You may continue to be at risk of arrhythmias even after successful surgery for mitral valve stenosis. You may need to take medications to lower that risk.
Other procedures
In some cases your surgeon may perform additional surgery at the time of your operation to try to keep your heart in normal rhythm, such as the maze procedure. This involves making a series of surgical incisions in the upper half of your heart (atria). These heal into carefully placed scars in the atria that form boundaries that force electrical impulses in your heart to travel properly to cause the heart to beat efficiently.
©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
The best way to prevent mitral valve stenosis is to prevent its most common cause, rheumatic fever. You can do this by making sure you and your children see your doctor when any of you have a sore throat. Untreated strep throat infections can develop into rheumatic fever. Fortunately, strep throat is easily treated with antibiotics.
©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
To improve your quality of life if you have mitral valve stenosis, your doctor may recommend that you:
If you're a woman with mitral valve stenosis, discuss family planning with your doctor before you become pregnant, because your heart works harder during pregnancy. How a heart with mitral valve stenosis tolerates this extra work depends on the degree of stenosis and how well your heart pumps. If you become pregnant, your cardiologist and obstetrician should evaluate you throughout your pregnancy, labor and delivery, and after delivery.
©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Want to know more about this article or other health related issues? Ask your question and we'll post some each week for CNN.com reader to discuss or for our experts to weight in.

| Most Viewed | Most Emailed |
