[net.med] Mitral Valve Prolapse

john@ur-tut.UUCP (John Gurian) (01/14/86)

	The term "prolapse" refers to a falling back into, or "lapsing back".
Mitral valve prolapse refers to a condition where the mitral valves flop
back into the left atrium during systole farther than they normally do.
This may be due to weak papillary muscles (the muscles that attach between the
valves and the heart wall and keep the valves from prolapsing normally), or
due to extra large or "floppy" mitral valve leaflets - the extra tissue
"balloons" into the left atrium during systole.

	The condition is entirely benign.  On physical exam, a "click" can
often be heard with a stethescope in the middle of systole (contraction),
leading to the alternate term "mid-systolic click syndrome".  This is due to
a clicking sound made as the ballooning leaflets are suddenly tensed at the end
of their journey.  Sometimes, a systolic murmur is heard, as some blood is
regurgitated into the left atrium.  Often, no physical signs can be elicited,
and the diagnosis must be made by ultrasound.

	The condition may be caused by rheumatic heart disease (rheumatic fever)
but often the leaflets were just formed that way.

	Again, the condition is entirely benign.  Often, even when a loud murmur
is present, the patient has no symptoms, the condition being picked up
incidentially during a physical.  Infrequently, chest pains (often very
frightening to the patient) will be present sporadically; these may be due
to stress placed on the papillary muscles as the are overstretched.  There
is nothing that a person with this condition cannot do that a normal person
could not.  If chest pain is present, it is something that must be learned to
live with.  Exercise presents no problem and in fact could be beneficial,
since it increases the cardiac reserve.

	In cases of more severe chest pains & palpitations, with clear evidence
of cardiac arrhythmias on EKG, propanolol may be useful as an anti-arrhythmic
drug.

	Despite its benign condition, in cases where symptoms ARE present,
it's probably prudent to get re-evaluated every 2-3 years just to make sure
there is no progression.

	One important caveat: penicillin should be taken before and after any
dental work is done, since bacteria introduced via the oral mucosa can seed in
the abnormal mitral valve and lead to bacterial endocarditis, a SERIOUS
infection.  Other than this one precaution, the patient has nothing to worry
about.  It is more psychologically stressful than physically harmful.

	About 5-10% of women have the condition; one study suggested as many
as 15-20% of women may have MVP.  I'm not sure on the figures for men, except
that they're lower.

						John Gurian
						Univ. Rochester
						School of Medicine
						!rochester!tut!john