What circulation system is affected if the mitral valve does not close properly?

The pulmonary circulation system is affected if the mitral valve does not close properly.

The mitral valve is located between the left atrium and the left ventricle of the heart. It prevents blood from flowing backward from the ventricle to the atrium when the ventricle contracts. If the mitral valve does not close properly, blood can leak back into the atrium, which can lead to a condition called mitral regurgitation.

Mitral regurgitation can cause a number of symptoms, including shortness of breath, fatigue, and chest pain. It can also lead to heart failure if left untreated.