Mitral Valve Stenosis

What Is Mitral Valve Stenosis?

Mitral valve stenosis is a condition in which the heart's mitral valve is narrowed or stiff. Stenotic mitral valve don’t open properly, blocking blood flowing through the left ventricle, the main pumping chamber of the heart. The upper heart chamber swells as pressure builds up. Blood may flow back into the lungs. Fluid then collects in the lung tissue (pulmonary edema),which can cause difficulty breathing, feelings of tiredness, and other problems.

What Causes of Mitral Valve Stenosis?

The main cause of mitral valve stenosis is an infection called rheumatic fever, which can be a complication of untreated strep infections. Rheumatic fever (which is now rare in the United States, but still common in developing countries) can scar the mitral valve. The valve problems develop five to ten years after the rheumatic fever.

Other factors can cause mitral stenosis in adults as well. As people age, excessive calcium deposits can build up around the mitral valve, which sometimes cause significant mitral valve stenosis. Radiation treatment to the chest and some medications also may cause mitral valve stenosis. Children may be born with mitral stenosis (congenital) or other birth defects involving the heart that cause mitral stenosis. Often, there are other heart defects present, along with the mitral stenosis. Mitral stenosis may run in families.

What Are the Symptoms of Mitral Valve Stenosis?

Symptoms of mitral valve stenosis can include fatigue with increased physical activity, shortness of breath when lying down, swollen feet or ankles, heart palpitations, frequent respiratory infections, heavy coughing, and rarely, chest discomfort or chest pain. These symptoms are typically the result of pressure building up in the heart and backing up into the lungs.

Not all people with mitral valve stenosis have symptoms.  Some may feel fine or have only minimal signs and symptoms for decades. However, mild problems can suddenly get worse. Symptoms may appear or worsen with any increase in heart rate, such as during exercise, or they may be triggered by pregnancy or other stress on the body, like an infection.

Mitral valve stenosis may also produce a number of signs that a doctor can find on examination or with further testing. These may include:

  • Heart murmur
  • Lung congestion
  • Irregular heart rhythms (arrhythmias)
  • Pulmonary hypertension
  • Blood clots.

If left untreated, mitral valve stenosis can lead to complications such as heart failure and atrial fibrillations.

How is Mitral Stenosis Treated? 

The only corrective treatments for mitral stenosis are procedures to repair or replace the mitral valve. A procedure may not be needed right away: if tests reveal mild-to-moderate mitral valve stenosis and no symptoms are present, there's generally no need for immediate valve repair or replacement.

When a procedure is necessary, it can take the form of: 

  • Balloon Valvuloplasty: This nonsurgical procedure uses a soft, thin tube (catheter) tipped with a balloon. A doctor guides the catheter through a blood vessel in the arm or groin to the heart and into the 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 the body. Balloon valvuloplasty can relieve mitral valve stenosis and its symptoms. This procedure may not be appropriate if the valve is both tight (stenotic) and leaky (regurgitant) or if the valve is too heavily calcified. It's also not performed if there's a blood clot in a chamber of the heart, because of the risk of dislodging it. The procedure may need to repeated if problems recur. 

  • Mitral Valve Repair: Mitral valve repair surgery is also called valvuloplasty and is performed using traditional surgical tools. During surgery, a cardiac surgeon may make repairs such as separating fused valve leaflets and removing obstructions on or near the mitral valve. This helps to clear the valve passageway. Surgery may need to be repeated if mitral valve stenosis develops again in the years following. 

  • Mitral Valve Replacement: Most people with mitral valve stenosis who need surgery will have mitral valve replacement. A cardiac surgeon will remove the narrowed mitral valve and replace it with a mechanical valve or a tissue valve. The procedure involves all the steps of traditional heart surgery such as sternotomy and cardiopulmonary bypass.

In terms of replacement valves: 

  • Mechanical valves are made completely of mechanical parts, which are non-reactive and tolerated well by the body. People with mechanical valves need to take an anticoagulant medication, such as warfarin (Coumadin), for the rest of their life to reduce the risk of blood clotting and stroke.

  • Biological valves (also called tissue or bioprosthetic valves) are made of tissue, but they may also have some artificial parts to provide additional support and allow the valve to be sewn in place. Biological valves can be made from pig tissue (porcine), cow tissue (bovine), or pericardial tissue from other species. These valves do not require being on long-term blood thinning medication. 

For some people with mitral valve stenosis and an irregular heart rhythm, an additional surgery may be performed at the time of their mitral valve operation. One such procedure, called the MAZE procedure, 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. Today the MAZE procedure is more commonly performed by radiofrequency ablation or cryoablation, which mimic incisions but leave no extra incisions in the atria.

Medications cannot correct a defect in the mitral valve, however, certain drugs can reduce symptoms and prevent further damage by easing the heart's workload and regulating the heart's rhythm. Medications for mild to moderate mitral stenosis may include: 

  • Diuretics (which remove excess fluid)
  • Blood thinners (also called anticoagulants)
  • Beta blockers (which help with heart rate and blood pressure)
  • Calcium channel blockers (which help control blood pressure)
  • Anti-arrhythmic medications (which control rhythm problems, if present)

If I Have Mitral Valve Stenosis, What Are My Next Steps?

If you are having symptoms of mitral valve stenosis and need to confirm the diagnosis, you should schedule an appointment with a cardiologist. If you have already been diagnosed and need treatment or a second opinion, our cardiac surgeons are here to help.

Request an appointment today.

Next Steps

If you have heart disease and need help, we’re here for you. To get started today, call (212) 305-2633 or use our appointment request form.

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