Complications

When it's mild, mitral valve regurgitation usually does not cause any problems. However, severe mitral valve regurgitation can lead to complications, including:

• Heart failure. Heart failure results when your heart can't pump enough blood to meet your body's needs. Severe mitral valve regurgitation places an extra strain on the heart because, with blood pumping backward, there is less blood going forward with each beat. The left ventricle gets bigger and, if untreated, weakens. This can cause heart failure.

  Also, pressure builds in your lungs, leading to fluid accumulation, which strains the right side of the heart.

• Atrial fibrillation. The stretching and enlargement of your heart's left atrium may lead to this heart rhythm irregularity in which the upper chambers of your heart beat chaotically and rapidly. Atrial fibrillation can cause blood clots, which can break loose from your heart and travel to other parts of your body, causing serious problems, such as a stroke if a clot blocks a blood vessel in your brain.
• Pulmonary hypertension. If you have long-term untreated or improperly treated mitral regurgitation, you can develop a type of high blood pressure that affects the vessels in the lungs (pulmonary hypertension). A leaky mitral valve can increase pressure in the left atrium, which can eventually cause pulmonary hypertension. This can lead to heart failure on the right side of the heart.