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 untreated, mitral valve stenosis can lead to complications such as:

  • Heart failure. Heart failure is a condition in which your heart can't pump enough blood to meet your body's needs. A narrowed mitral valve interferes with blood flow through your heart and from your heart out to the rest of your body. In addition, pressure builds up in your lungs, leading to fluid accumulation. Eventually, this places a strain on the right side of the heart, which leads to fluid buildup in either your ankles or abdomen or both areas (edema).
  • Heart enlargement. The pressure buildup of mitral valve stenosis results in enlargement of your heart's upper left chamber (atrium). At first this change helps your heart pump more efficiently, but eventually, it damages your heart's overall health. Additionally, pressure can build up in your lungs and cause pulmonary congestion and hypertension.
  • Atrial fibrillation. In mitral valve stenosis, the stretching and enlargement of your heart's left atrium may lead to a heart rhythm irregularity called atrial fibrillation. In atrial fibrillation, the upper chambers of your heart beat chaotically and too quickly.
  • Blood clots. Left untreated, atrial fibrillation can put you at risk of blood clots forming in the upper left chamber of your heart, where blood pools in mitral valve stenosis. Blood clots from your heart may break loose and travel to other parts of your body, causing serious problems. For example, a blood clot that travels to your brain and blocks a blood vessel there could cause a stroke.
  • Lung congestion. Another possible complication of mitral valve stenosis is pulmonary edema — a condition in which blood and fluid back up into your lungs. This causes congestion of the lungs, leading to shortness of breath and, sometimes, coughing up of blood-tinged sputum.
Sep. 15, 2011