Mitral regurgitation is leakage of blood backward through the mitral valve each time the left ventricle contracts.
Watch an animation of mitral valve regurgitation
A leaking mitral valve allows blood to flow in two directions during the contraction. Some blood flows from the ventricle through the aortic valve — as it should — and some blood flows back into the atrium.
What is the problem that results from mitral regurgitation?
Leakage can increase blood volume and pressure in the area. The increased blood pressure in the left atrium can increase pressure in the veins leading from the lungs to the heart (pulmonary veins).
If regurgitation is severe, increased pressure may result in congestion (or fluid build-up) in the lungs.
What are the symptoms of mitral valve regurgitation?
Mild mitral regurgitation may not have any symptoms.
When regurgitation is more severe, a person may have palpitations, especially when lying on the left side.
If regurgitation is severe enough, the heart may enlarge to maintain forward flow of blood, causing heart failure (when the heart does not pump enough blood to the body). This may produce symptoms
ranging from shortness of breath during exertion, coughing, congestion around the heart and lungs, swelling of the legs and feet.
What conditions may be related to mitral regurgitation?
The left atrium tends to enlarge due to the extra blood volume leaking back from the ventricle. An enlarged atrium may develop a rapid and disorganized movement (a disorder called atrial fibrillation),
which reduces the heart’s ability to pump efficiently.
A fibrillating atrium is just a quivering, not a pumping, that will not allow blood to flow normally, which increases the risk for blood clots that may cause a stroke.