What is MVP?
Click here for a quick and easy review of the cardiac chambers and valves.MVP occurs when abnormalities in the mitral valve allow it to flop (i.e., to prolapse) back into the left atrium as the left ventricle contracts, thus allowing a certain amount of backflow of blood (i.e. regurgitation) from the ventricle to the atrium. In general, the abnormality that allows prolapse to occur is a congenital excess of tissue on the valve, making it "floppy."
The diagnosis of MVP is generally suspected when the doctor hears the classic “click-murmur” while listening to the heart (the click being caused by the prolapsing of the mitral valve; the murmur by the subsequent regurgitation of blood), and is confirmed with an echocardiogram.
MVP is extremely common. Roughly 2% to 4% of the general population will have MVP on echocardiographic screening (a much lower proportion, however, than previously thought). Further, there is often a genetic predisposition to MVP. If a person has true MVP, it is likely that about 30% of his/her close relatives will also have it.
Why is MVP significant?
Two clinical problems are caused directly by MVP: significant mitral regurgitation, and bacterial endocarditis (i.e., infection of the mitral valve).If severe enough, mitral regurgitation can lead to enlargement of the cardiac chambers, weakening of the heart muscle, and ultimately, to heart failure. Fortunately, MVP tends NOT to cause significant mitral regurgitation. Only about 5% of patients with true MVP will develop significant mitral regurgitation over their lifetimes.
The risk of developing a cardiac infection – endocarditis – increases any time a leaky valve is present within the heart. Fortunately endocarditis associated with MVP is rare, but prophylactic antibiotics should be prescribed for these individuals prior to any procedure likely to “seed” the bloodstream with bacteria. (The most common procedure that does this is a visit to the dentist.)
What is the prognosis with MVP?
The vast majority of patients with MVP can expect to lead completely normal lives, without any symptoms due to their MVP and without any decrease in longevity. Indeed, some studies suggest that patients with MVP may enjoy an increased lifespan as compared to the general population.
What other clinical problems have been attributed to MVP?
Because MVP is common, it has been associated with a myriad of conditions that probably do not have anything to do with the MVP itself. Here are the more common conditions that have been associated with MVP, but whose actual relationship to MVP is tenuous at best:Anxiety, chest pain, palpitations. While it is commonly believed that MVP causes these symptoms, most individuals with MVP do not experience them, and most individuals with anxiety, chest pain and palpitations do not have MVP.
Stroke or sudden death. It has never been shown that MVP itself causes either stroke or sudden death, or that the incidence of MVP is higher than normal in patients who experience these problems. Patients with severe mitral regurgitation – from any cause – have an increased risk of stroke and sudden death, but those with run-of-the-mill MVP probably have the same risk as the general population.
The dysautonomia syndromes: chronic fatigue syndrome, vasovagal (or neurocardiogenic) syncope, panic attacks, fibromyalgia. (Click here for a review of dysautonomia.) It is not at all clear that patients with MVP have an increased propensity to the symptoms associated with the dysautonomias (palpitations, anxiety, fatigue, aches and pains.) But in their desperation to make a diagnosis in patients complaining of such symptoms, and thus by ordering every test known to man, doctors have found (naturally) that a proportion of these difficult patients have MVP. Doctors have thus coined the phrase “Mitral Valve Prolapse Syndrome” (MVPS) to explain it. Again, however, these conditions are very often present without any sign of MVP (no matter how urgently one looks). Whether the MVP actually has anything whatever to do with these symptoms is very doubtful.
