INTRODUCTION — Mitral valve prolapse (MVP) is associated with a wide variety of clinical features. There are potentially serious arrhythmic and nonarrhythmic complications such as sudden death and infective endocarditis. (See "Arrhythmic complications of mitral valve prolapse" and "Nonarrhythmic complications of mitral valve prolapse".)
In addition, a variety of more nonspecific complaints have been associated with MVP. Atypical or non-anginal chest pain is the most common symptom attributed to MVP. Other manifestations may include:
●Palpitations
●Dyspnea
●Exercise intolerance
●Dizziness or syncope
●Panic and anxiety disorders
●Numbness or tingling
●Skeletal abnormalities
●Abnormal resting and exercise electrocardiograms
Any combination of these symptoms and signs plus the typical auscultatory features of MVP have been defined as the MVP syndrome. This topic will review the validity, pathophysiology, and treatment of this disorder.
VALIDITY OF THE SYNDROME — The large number of symptoms directly attributed to mitral valve prolapse (MVP) may be coincidental. The questionable link between MVP and the above list of nonspecific symptoms may have originated because of inaccurate study designs and selection bias. As an example, many studies may not have had well-matched control groups, which is essential because many of the symptoms attributed to MVP commonly occur in the general population. In addition, studies based at tertiary care centers may have attracted potentially more symptomatic patients than those who seek medical attention at smaller medical centers. Thus, trials performed at these centers may have overestimated the true prevalence of symptomatic patients with MVP.
Appropriately controlled clinical studies suggest that patients with MVP and control subjects are equally symptomatic. Support for this comes from a report of the Framingham Heart Study [1]. Eighty-four patients with MVP based upon current two-dimensional echocardiographic criteria were compared to 3403 control subjects without MVP; chest pain, dyspnea, syncope, congestive heart failure, atrial fibrillation, and electrocardiogram abnormalities were equally prevalent in affected patients and matched controls [1]. Two findings that were more common in MVP were an asthenic body habitus and a greater degree of mitral regurgitation.
It is possible, however, that autonomic and neuroendocrine dysfunction found in some patients with MVP may underlie some of the symptoms associated with this disorder. One study, for example, compared the clinical symptoms in affected (ie, with MVP) first degree relatives of patients with MVP with those of unaffected relatives and spouses in an attempt to overcome selection bias [2]. Eighty-one first degree relatives had MVP as determined by echocardiography while 172 relatives and 60 spouses were not affected. Palpitations, lower systolic pressure, low body weight, and thoracic bony abnormalities were more common in relatives with MVP. In contrast, relatives with MVP showed no significant increase over unaffected relatives or spouses in prevalence of chest pain, dyspnea, panic attacks, high anxiety, or repolarization abnormalities.
PATHOPHYSIOLOGY — Symptoms attributed to mitral valve prolapse (MVP) cannot clearly be explained by the degree of prolapse or mitral regurgitation. However, autonomic or neuroendocrine dysfunction has been suggested as a possible cause of the nonspecific symptoms in many patients with MVP. Patients with MVP tend to exhibit the following findings when compared to controls [3,4]:
●Elevated urine and plasma catecholamine levels
●An exaggerated heart rate response to phenylephrine
●A less than expected bradycardic response to the dive reflex
●The reproduction of symptoms with isoproterenol infusion
The specificity of these findings for MVP is uncertain. One study found a series of abnormalities in patients with symptoms of autonomic dysfunction, which did not correlate with the presence or absence of MVP [5].
An association between panic disorder and MVP has also been suggested by several studies, including a meta-analysis [6]. However, these studies have been criticized because of inconsistencies in the diagnostic criteria used for both panic disorder and MVP, and the use of imperfectly matched controls. In addition, panic disorder and MVP are both common illnesses with similar age and gender distributions, suggesting that their association may only be a coincidence.
CLINICAL MANIFESTATIONS AND TREATMENT — The symptomatic relief of patients with mitral valve prolapse (MVP) may require both general and pharmacologic measures. Reassurance about the benign nature of the disorder is often adequate to reduce the severity of symptoms in many patients. Many patients also appear to benefit from a change in lifestyle, including aerobic exercise training; the avoidance of stimulants (caffeine), alcohol, and undue fatigue; and a reduction in stress. One study, for example, evaluated the efficacy of aerobic exercise (three times per week for 12 weeks) in 32 symptomatic women with MVP [7]. Compared with control subjects, the exercise group showed a decrease in anxiety scores, an increase in general well-being, and a decline in the frequency of chest pain, fatigue, dizziness, and mood swings.
It is important that a lifestyle modification program be started gradually and consistently. A response to this regimen may take several weeks and frequent encouragement is often required.
Magnesium supplementation may benefit a subset of patients with symptoms and magnesium deficiency [8,9]. One study of 141 patients with MVP found a significant number of MVP patients had a low serum magnesium compared to 40 healthy controls (60 versus 5 percent) [8]. Patients with low serum magnesium received five weeks of magnesium supplementation or placebo; magnesium supplementation resulted in a significant reduction in weakness, chest pain, palpitations, and anxiety. A decrease in the mean daily excretion of norepinephrine was noted in the magnesium-treated group. A study of 230 pediatric patients with MVP found hypomagnesemia in 8.2 percent of subjects. Five weeks of magnesium supplementation gave significant relief of chest pain but no change in palpitations, fatigue, or dyspnea [9].
Chest pain — The chest pain attributed to MVP is usually atypical and easily distinguishable from angina. The pain is generally mild but can be disabling and recurrent.
Patients with chest pain and MVP should be evaluated in the same manner as any patient with chest discomfort. (See "Outpatient evaluation of the adult with chest pain".) If no cause is found, we do not recommend the use of beta blockers, because there is no evidence that they are effective. However, a modest change in lifestyle including the initiation of an exercise program may be beneficial [7].
Anxiety — Patients presenting with symptoms diagnostic of anxiety disorder, panic disorder, or depression should be treated for these illnesses with the same indications as those without MVP. (See "Generalized anxiety disorder in adults: Epidemiology, pathogenesis, clinical manifestations, course, assessment, and diagnosis" and "Unipolar depression in adults: Assessment and diagnosis".)
Palpitations — Palpitations are a common presenting complaint in MVP. The evaluation of patients with symptomatic palpitations is similar to that in patients without MVP. Palpitations are often associated with ventricular premature beats, but supraventricular arrhythmias can also occur. (See "Arrhythmic complications of mitral valve prolapse".) In addition, palpitations may be reported by patients at a time when an arrhythmia is absent on continuous ambulatory recording. Thus, the presence of an arrhythmia should be confirmed before beginning antiarrhythmic therapy. Beta blockers may be helpful in patients who present with hyperadrenergic symptoms such as tachycardia, palpitations, nervousness, and an exaggerated heart rate response to exercise.
Hyperventilation — Symptoms of hyperventilation, including dyspnea, dizziness, numbness, and tingling, are common in MVP. Objective exercise testing in these symptomatic patients is usually normal and the symptoms frequently respond to lifestyle modifications.
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Cardiac valve disease".)
INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, “The Basics” and “Beyond the Basics.” The Basics patient education pieces are written in plain language, at the 5th to 6th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10th to 12th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.
Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on “patient info” and the keyword(s) of interest.)
●Basics topic (see "Patient education: Mitral valve prolapse (The Basics)")
SUMMARY AND RECOMMENDATIONS
●Atypical or non-anginal chest pain is the most common symptom attributed to mitral valve prolapse (MVP). Other manifestations may include palpitations, dyspnea, exercise intolerance, dizziness or syncope, and panic and anxiety disorders. Any combination of these symptoms and signs plus the typical auscultatory features of MVP have been defined as the mitral valve prolapse syndrome.
●The large number of symptoms directly attributed to MVP may be coincidental. It is possible, however, that autonomic and neuroendocrine dysfunction found in some patients with MVP may underlie some of the symptoms associated with this disorder.
●Reassurance about the benign nature of MVP syndrome is often adequate to reduce the severity of symptoms in many patients. Many patients also appear to benefit from a change in lifestyle, including aerobic exercise training; the avoidance of stimulants (caffeine), alcohol, and undue fatigue; and a reduction in stress.
