QUESTION: My doctor heard a ``click'' and a murmur when
listening to my heart and told me that I have mitral valve
prolapse. He reassured me that it's not unusual in women and that
I'm perfectly healthy, but I'm still worried. How serious is this
condition?
MINKIN: Your question comes at a good time, since improved
technology and a better understanding of the anatomy of the heart
are giving us a clearer picture of mitral valve prolapse and its
possible complications.
In fact, a lot of people who have been told that they have MVP
actually don't! You may be one of them.
MVP is a congenital defect of the valve through which blood
flows when it leaves the atrium, or upper left chamber of the
heart, and enters the ventricle, the lower left chamber. The mitral
valve is supposed to snap shut to make a tight seal so that blood
can't flow back into the atrium. With MVP, over time the valve
becomes thickened and floppy, creating the sounds that your doctor
heard.
About 10 percent to 15 percent of the people who have walked
into my office have been told at some point that they have MVP. In
fact, it has earned the reputation of being the most common form of
heart valve disease. Previous estimates said that 5 percent to 15
percent of the population -- primarily young women -- were affected.
Many people came away from their MVP diagnosis with a lot of
anxiety. Some, on the advice of their doctor, overused antibiotics
before dental or medical procedures to avoid potential infection.
The fear is that if blood is ``backflowing'' across the valve in
the heart, bacteria in the blood could cause an infection of the
valve. And, of course, it's during dental and medical procedures
that bacteria are most likely to get into the bloodstream.
But a new study published last summer, based on 3,500 subjects
from the highly regarded Framingham Heart Study, had some
reassuring findings that are helping to clear up much of the
confusion among patients and physicians regarding MVP (New England
Journal of Medicine, July 1, 1999). The study concluded that MVP is
not as common as previously thought and while more women are
diagnosed, there's not a dramatic gender difference.
In fact, in this study only 2.4 percent of the subjects actually
had MVP, 60 percent of whom were women.
This is a very reasonable study and confirms what many of us
have found in our clinical experience, namely that MVP is
overdiagnosed,'' comments Dr. Lynda E. Rosenfeld, associate
professor of medicine and pediatrics at Yale University School of
Medicine.
The only way to accurately diagnose MVP is with an
echocardiogram, a noninvasive test which uses sound waves to look
at the heart and how it is working. So make sure that you see a
cardiologist for an echocardiogram to confirm your doctor's
suspicions.
And now, more precise two-dimensional echocardiograms -- the gold
standard for diagnosing MVP -- can identify those patients who truly
have MVP and are at risk for complications. Also, there's new,
updated criteria for diagnosing MVP that most of the ``echo'' labs
are using.
If you do have MVP, there's no need to panic. But it's good to
be aware of some symptoms that people with MVP may experience, such
as anxiety, heart palpitations and mild chest pain (not angina).
One of the other reassuring findings from this new study is that
people with MVP don't seem to be more likely than those without the
condition to suffer heart failure, stroke, heart arrhythmias, or
fainting, all of which were previously thought to be frequent
complications of MVP. As with people without MVP, the best
protection against these serious problems is a healthy diet and
exercise.
Sometimes there is mitral regurgitation with MVP, which means
that blood is leaking backward in the heart through the mitral
valve. Your doctor should check for it if you are diagnosed with
MVP. Anyone with MVP should have an echocardiogram at least every
five years to ensure that the condition is not progressing and that
backflow of blood is not enlarging the heart.
One real risk of MVP is the development of a bacterial infection
of the heart valve. If you have been properly diagnosed with MVP,
you will need to take antibiotics ahead of time before having
dental work done or before undergoing surgery or an invasive
diagnostic procedure. Be sure to make your dentist and other
doctors aware of this.
