Mitral Valve Prolapse

Q:  I've been told that I have mitral valve prolapse and need to be given antibiotics before dental procedures. What exactly is mitral valve prolapse and why are antibiotics necessary?

A:  Mitral valve prolapse is a condition affecting one of the four major heart valves. All heart valves are designed as one-way valves that prevent the backflow of blood. When a valve prolapses, it bulges or stretches when closing, oftentimes producing a click or snapping sound that can be heard through a stethoscope. If the valve opens slightly as well and allows blood to leak in the wrong direction, a murmur can be heard, caused by a spurt under high pressure through a small opening.

For most people, mitral valve prolapse is a harmless condition. For a very few, chest pain, shortness of breath and abnormal heart rhythms may occur, most of which are still benign. If you have prolapse and a murmur, your heart valves are at a greater risk of being infected. This is the reason for antibiotics before dental work, because with cleaning and other procedures, bacteria from the mouth can be temporarily introduced into the bloodstream.

The best way to diagnose the condition if your doctor has any doubt is through an echocardiogram. I would add that I saw a patient who carried this diagnosis in whom I could not hear a click or a murmur. The echocardiogram showed a normal mitral valve and now she no longer needs antibiotics.

"Your Health" provides easy-to-understand information about common health conditions.