Mitral valve prolapse severe enough to cause regurgitation may directly cause pressure in the atrium.

Mitral valve prolapse severe enough to cause regurgitation may directly cause INCREASE pressure in the LEFT atrium. Mitral valve prolapse is a medical condition in which the the two valve flaps of the mitral valve do not close properly, bulging upward into the left atrium. The condition may be mild or severe. Heart surgery may be required in case of the severe one.