Infective endocarditis may cause
mitral valve stenosis or
mitral valve regurgitation (MR), or it may be a
complication of either of these diseases. The infection is considered a
complication when it is actually caused by the mitral valve condition.
As a cause
While an infection in the heart (infective endocarditis) is a
common cause of other valve conditions, it is rarely responsible for mitral
valve stenosis.
When bacteria begin to grow on the mitral valve or inside the
heart, they form a colony, known as a vegetation, which may grow to be several
centimeters in size. When growing on the valve, they can block its opening,
causing stenosis, or more commonly they scar the valve, making it difficult for
the valve to close completely, causing regurgitation. Vegetations can also
cause a perforation, leading to acute mitral valve regurgitation, which
requires emergency treatment.
As a complication
If you have an
artificial valve, getting endocarditis could be very
dangerous for you. The artificial valve gives bacteria a place to move in,
attach, and grow. When bacteria settle in, they expand and clump together,
becoming a larger mass attached to your heart muscle or valve. As these clumps
of bacteria become larger, pieces are likely to break off. These pieces that
break off act much like a blood clot and can block your arteries, causing a
heart attack or
stroke. They can also spread the infection throughout
your body by traveling through your bloodstream.
Certain
dental or surgical procedures could introduce bacteria
into your blood and put you at risk for endocarditis. So to prevent an
infection, you may need to take
antibiotics before these procedures.
If you develop an infection, endocarditis can be treated with
intravenous antibiotics. This will be in much larger doses than the oral
antibiotics you take to prevent infection, and it will be given for a much
longer period of time. A typical course of antibiotics to treat endocarditis is
daily for four to six weeks, compared to one dose before surgery and one dose
afterwards for preventive purposes.
For more information, see the topic Endocarditis.