The two sides of the floppy tube represent the anterior and posterior leaflets of the valve. Your fingers are the chordae tendinae, long cords of tissue that hold the leaflets in the right position so that the valve will open and close properly. In the human valve, there are many chordae, which are attached to the leaflets along the free edge, and also closer to the middle of the leaflets. Because the two leaflets aren't making contact properly, some blood can flow backwards through the valve into the left atrium. Many people have some degree of mitral prolapse and it is most frequently diagnosed in young women.
Mitral prolapse is present in almost one in four young women.
The degree of prolapse is important, mild mitral prolapse is quite common such that is regarded as a normal variant by most doctors, however if the prolapse is severe then you may have significant symptoms and require surgery. At this point I want to stress that only people with severe mitral prolapse usually require any kind of medical intervention. Many people live completely normal lives and are completely oblivious to the fact that they have minor mitral prolapse. What follows is a description of some of the symptoms that patients with severe mitral valve prolapse may experience. A prolapse that causes severe regurgitation may eventually cause congestive heart failure and, if untreated, ultimately death.