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Mitral Valve Prolapse in Active Patients: Recognition, Treatment, and Exercise Recommendations

Elizabeth Joy, MD

THE PHYSICIAN AND SPORTSMEDICINE - VOL 24 - NO. 7 - JULY 96


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In Brief: In most people, mitral valve prolapse, which affects women more than men, is a benign condition with few or no symptoms. But in some patients it poses a significant problem. Potential sequelae include endocarditis, serious arrhythmia, and sudden death. Although a midsystolic click followed by a late systolic murmur is characteristic, definitive diagnosis requires echocardiography. Treatment ranges from education and reassurance in those who have mild disease to valve replacement in severe cases. Most athletes who have mitral valve prolapse can safely participate in all activities. Those with evidence of significant valvular disease, serious arrhythmia, or a family history of sudden death due to mitral valve prolapse, however, should participate only in low-intensity competitive sports.

Mitral valve prolapse (MVP) affects up to 5% of the general population and up to 17% of young women and girls (1). Because of its relatively high prevalence, this disorder is of particular concern to physicians caring for athletes and other active patients. In most individuals, MVP is benign and causes few, if any, symptoms. People with more significant valvular abnormalities, however, appear to be at greater risk for serious complications, including bacterial endocarditis, arrhythmia, and sudden death (2). Identifying patients at risk for complications of MVP, therefore, is paramount before optimal treatment and exercise recommendations can be implemented.

Pathophysiology and Epidemiology

MVP is, by definition, abnormal systolic displacement of the mitral valve leaflets superiorly and posteriorly from the left ventricle into the left atrium (3). MVP appears to be a heterogeneous disease, with affected patients demonstrating a continuum of both valvular disease severity and symptomatology.

MVP is most often a primary, autosomally dominant condition (3). Inherited abnormalities of valvular connective tissue result in redundancy and/or thickening of valve leaflets. This leads to various degrees of distensibility, poor leaflet opposition, and subsequent prolapse. Recent evidence suggests that these aberrations of leaflet microarchitecture may also be accompanied by widespread abnormalities of connective tissue elsewhere in the body (4). MVP may also be present in people with other connective tissue diseases such as Marfan syndrome and Ehlers-Danlos syndrome (3,4).

In addition to the valvular changes in MVP, a subset of patients have associated neuroendocrine abnormalities and autonomic dysfunction. This results in a wide variety of symptoms involving multiple organ systems and has been referred to as mitral valve prolapse syndrome (MVPS) (4,5). Patients complain of fatigue, dyspnea, chest pain, palpitations, panic attacks, and many other symptoms that cannot be explained on the basis of their valvular abnormalities alone (5). Research has demonstrated high adrenergic activity in people with MVPS. This is thought to be a result of increased serum levels of catecholamines coupled with adrenergic hyperresponsiveness (4). This may explain the "hypersensitivity" to certain stressful stimuli demonstrated by some MVPS patients.

MVP can affect both men and women; however, more than 60% of adults with MVP are women (3). The prevalence of MVP in athletes is unknown.

Symptoms of Valvular Disease

Two groups of patients with documented prolapse emerge from the literature: those whose symptoms are directly related to their valvular disease, and those whose symptoms cannot be explained on the basis of their valvular disease alone. The first group has been referred to as MVP-anatomic, and the second group as having MVPS (4,5). Some symptom crossover exists between the two groups, and researchers disagree as to whether these two distinct groups even exist (3). It is believed that palpitations are one of the few symptoms experienced by patients who have MVP that has a basis in valve dysfunction alone (3).

Those with MVPS have a constellation of systemic symptoms. The pathogenesis of these symptoms is not well understood but is thought to be multifactorial, including adrenergic hyperresponsiveness, autonomic dysfunction, and an abnormal renin aldosterone response to volume depletion. These patients often have low resting blood pressure, thought to be related to low intravascular volume. Hypotension is thought to contribute to the dizziness or syncope that some patients who have MVP experience (4). This is of particular importance to athletes with MVP because they may be more sensitive to dehydration induced by vigorous physical activity, and thus at higher risk for exercise-induced syncope.

Other symptoms reported by those with both MVP and MVPS include chest pain, fatigue, dyspnea, exercise intolerance, headache, sleep disorders, anxiety and panic attacks, irritable bowel symptoms, and vascular symptoms such as flushing and cold extremities (5).

Key Diagnostic Findings

The workup for MVP and MVPS is the same. MVP is usually recognized by its characteristic auscultatory findings: a midsystolic click followed by a late systolic murmur. The click results from a tightening of the chord-leaflet structures at the time of maximum prolapse, and the murmur from mitral regurgitation (5). Neither the presence nor absence of these findings, however, confirms or excludes the diagnosis of MVP. Maneuvers that reduce left ventricular volume, such as having the patient sit or stand, cause the click and murmur to move closer to the first heart sound. Conversely, having the patient squat will increase left ventricular volume, causing the murmur to either disappear or decrease in intensity. When a click or murmur is present and responds appropriately to the aforementioned maneuvers, an auscultatory diagnosis of MVP can be made.

Echocardiography has markedly improved recognition and assessment of MVP. Patients with auscultatory findings and/or a history suggestive of MVP should undergo an echocardiogram to further evaluate leaflet structure and identify any regurgitation. The echocardiographic diagnosis is made when one or both mitral valve leaflets protrudes or billows into the left atrium in the apical long-axis view (3). Mild bowing of normal-appearing leaflets seen in the four-chamber view probably represents a normal variant and does not warrant a diagnosis of MVP.

Echocardiography can also help classify patients as having low, mild, moderate, or high risk of complications (table 1). Those who show no evidence of mitral regurgitation or valve thickening or redundancy are at lowest risk. Echocardiography is particularly useful for evaluating abnormalities in more severe forms of the disease. Thickening of the leaflets, enlargement of both leaflets and annulus, and significant systolic protrusion of one or more of the leaflets are associated with severe mitral regurgitation and convey a poorer prognosis (6,7). Two-dimensional echo also allows evaluation of atrial and ventricular anatomy and function (which can be altered by chronic mitral regurgitation).

______________________________________________________________________________
Table 1. Evaluation and Management of Mitral Valve Prolapse

______________________________________________________________________________
Risk                    Echo                 Other  
Category*               Evaluation           Tests             Treatment
______________________________________________________________________________
Low
MVP without valvular    Echocardiogram       Initial ECG       Education and 
deformity or            every 5 yr           24-hr Holter       reassurance 
regurgitation                                 monitor          For palpitations:
                                             Graded exercise    beta-blocker, 
                                              stress test       dietary changes,
                                                                and regular 
                                                                exercise
Mild
MVP with valvular       Echocardiogram       Initial ECG       Oral antibiotic  
deformity and no        every 2-3 yr         24-hr Holter       prophylaxis 
regurgitation                                 monitor          Treat even mild
                                             Graded exercise    hypertension
                                              stress test      Encourage weight 
                                             Stress             loss if needed 
                                              echocardiogram   Treat palpitations
                                                                as above  
Moderate
MVP with valvular       Echocardiogram       Initial ECG       Oral antibiotic
deformity and           every 2-3 yr         24-hr Holter       prophylaxis  
mild regurgitation                            monitor          Treat even mild
                                             Graded exercise    hypertension  
                                              stress test      Encourage weight     
                                             Stress             loss if needed 
                                              echocardiogram   Treat palpitations
                                                                as above
High
MVP with moderate-to-   Doppler echo-        Initial ECG       As above and  
severe regurgitation    cardiogram           24-hr Holter      closely monitor  
                        every yr              monitor          cardiac function
                                             Graded exercise   and replace  
                                              stress test      mitral valve 
                                             Stress            when necessary
                                              echocardiogram 
                                             Others based on 
                                              signs and 
                                              symptoms
______________________________________________________________________________
*Risk of having complications
 ECG = electrocardiogram
______________________________________________________________________________

Doppler echocardiography is useful in evaluating the size and intensity of the mitral regurgitant flow or jet. The severity of mitral regurgitation is determined by the regurgitant volume. Mitral regurgitation results in increased diastolic filling of the left ventricle and increased left atrial pressure. Patients with chronic regurgitation consequently have a hard time effectively increasing their cardiac output, and the increases in left atrial pressure and volume can lead to left atrial enlargement and atrial fibrillation. Eventually, both left and right heart failure can result if the mitral regurgitation is not treated appropriately (8).

Other tests to consider in the patient with MVP include electrocardiography to screen for conduction disturbance, 24-hour Holter monitoring to evaluate those with palpitations, graded exercise stress testing to monitor exercise tolerance, and stress echocardiography. The stress echo may prove helpful in identifying those at highest risk for certain complications. A recent study (8) shows that compared with a control group, patients with exercise-induced mitral regurgitation are more likely to develop congestive heart failure, syncope, and progressive mitral regurgitation leading to valve replacement. (For a primer on common sequelae, see "Complications of Mitral Valve Prolapse".)

The evaluation of chest pain in a patient with MVP is difficult. The etiology of chest pain in MVP is unclear, making the choice of diagnostic tests challenging. There are no characteristic electrocardiographic features. Graded exercise stress testing is unlikely to show evidence of ischemia, unless the patient also has risk factors for coronary artery disease. One should evaluate each patient individually with respect to the medical history, symptoms, and the situation in which symptoms occur.

Management and Risk Stratification

Management of MVP should be centered on patient education, symptom and risk management, and ongoing risk stratification (table 1). For those in the low-risk category, patient education is the only treatment indicated. It should focus on the generally benign nature of the condition and reassure patients that they can live long, healthy lives. Oral antibiotic prophylaxis is not required. Follow-up echocardiography in 5 years is reasonable, unless other symptoms warrant evaluation sooner (3).

Patients with mild regurgitation and/or valve abnormalities require oral antibiotic prophylaxis. Even mild hypertension should be treated, and weight loss should be encouraged in those who are overweight. Echocardiographic reevaluation at 2- to 3-year intervals is appropriate (3).

At highest risk are those who suffer from moderate-to-severe mitral regurgitation. This group is most likely to require valve replacement, and every effort should be made to reduce factors that increase regurgitation. In addition to reducing weight and controlling blood pressure, static exercise such as weight lifting should be avoided because it may result in dramatic increases in blood pressure, thereby worsening mitral regurgitation. High-risk patients require yearly Doppler evaluation. Valve replacement should be considered in patients who have worsening dyspnea and diminished left ventricular function (3).

In patients who have symptoms suggestive of MVPS, lifestyle modification is the key to reducing symptoms. Dietary changes such as avoidance of caffeine may reduce palpitations. Avoidance or restriction of products containing a lot of sugar may lessen the fatigue experienced by some MVPS sufferers. Liberal fluid intake and minimal alcohol and caffeine intake will minimize the effect that dehydration has on the hypovolemia experienced by some patients (5). Encouraging adequate sodium chloride intake in those with symptomatic hypotension may also help (4).

Medication management in patients who have MVP is fairly limited. In those with documented, hemodynamically stable, nonsustained tachyarrhythmias, or in those who have distressing palpitations, a cardioselective beta-blocker may be helpful. Patients who have atrial fibrillation need anticoagulation therapy, and they may need rate control with digoxin.

A family physician should seek cardiology consultation for anyone who has mitral valve disease with mitral regurgitation, significant arrhythmias, or a family history of sudden death due to MVP.

Exercise Guidelines

Aerobic exercise should be encouraged for all patients with MVP. One study (9) demonstrated that a 12-week aerobic exercise program improved the symptoms and functional capacity of women with documented MVP. Compared with the control group, the exercise group showed a significant decrease in anxiety, as well as increases in general well-being and functional capacity, and a decline in symptoms such as chest pain, fatigue, dizziness, and mood swings. A supervised program is recommended for those who have significant cardiac compromise.

The 26th Bethesda Conference (2,10,11) addressed the topic of exercise for athletes who have either MVP or mitral regurgitation. The recommendations:

Mitral valve prolapse. Athletes with MVP (having a structurally abnormal valve manifested by leaflet thickening and elongation) and without any of the following criteria can engage in all competitive sports:

  • History of syncope, documented to be arrhythmogenic in origin;
  • Family history of sudden death associated with MVP;
  • Repetitive forms of sustained and nonsustained supraventricular arrhythmias, particularly if exaggerated by exercise;
  • Moderate-to-marked mitral regurgitation; or
  • Prior embolic event.

Athletes with MVP and one or more of the aforementioned criteria can participate in only low-intensity competitive sports (class 1A, table 2: not shown) (11).

Mitral valve regurgitation (mild). Exercise recommendations vary for patients who have MVP with mild mitral regurgitation. Athletes in sinus rhythm with normal left ventricular size and function can participate in all competitive sports. Athletes in sinus rhythm or atrial fibrillation with mild left ventricular enlargement and normal left ventricular function at rest can participate in low and moderate static and moderate dynamic competitive sports (classes 1A, 1B, 2A, and 2B, table 2: not shown). Selected athletes can engage in some low and moderate static and low, moderate, and high dynamic competitive sports (classes 1A, 1B, 1C, 2A, 2B, and 2C, table 2: not shown). When a patient has atrial fibrillation, exercise testing can help ensure that the ventricular rate response to exercise will not be excessive.

Athletes with definite left ventricular enlargement or any degree of left ventricular dysfunction at rest should not participate in any competitive sports. Patients on chronic anticoagulation therapy should avoid sports involving body contact.

Conclusion

It's important to remember that MVP rarely results in serious complications. Nonetheless, people who have MVP must be identified—and their risk level assessed—for optimal management of symptoms and risk. Pursuing the appropriate work-up and proceeding with targeted therapy will allow patients to lead safe, healthy, active lives.


Complications of Mitral Valve Prolapse

(Back up to article)

Most patients who have mitral valve prolapse (MVP) will have a benign form with no significant complications (1). Serious sequelae, however, include mitral regurgitation, infective endocarditis, cerebrovascular accidents, and sudden death (2-5).

Mitral regurgitation. MVP is the most common cause of mitral valve regurgitation (1). Those with leaflet thickening and redundancy seem to be at highest risk for developing regurgitation (2). The risk of progressing to regurgitation also increases with age, and, surprisingly, seems to affect men more than women, despite the greater preponderance of women with MVP (1). Elevated blood pressure and high body weight may also increase one's risk for developing mitral regurgitation, and may explain the male majority.

Physical examination of patients with significant regurgitation will reveal a holosystolic or nearly holosystolic mitral regurgitant murmur. This can subsequently be confirmed with Doppler echocardiography. The larger the regurgitant jet area, the more severe the regurgitation. If the area is 4 to 8 cm2, mitral regurgitation is moderate, and if greater than 8 cm2, it is severe (6).

Infective endocarditis. Leaflet thickening and redundancy also put patients at risk for infectious bacterial endocarditis (2,3). While the risk of developing endocarditis is low—1% to 3.5% (1-3)—oral antibiotic prophylaxis should be prescribed prior to invasive procedures for patients who have leaflet thickening or redundancy.

Cerebrovascular accidents. The incidence of stroke in MVP patients is higher than in the general population (1). The reason is not clearly understood, and currently there are no clinical clues to predict the risk of stroke. Those with severe mitral regurgitation seem to be at greater risk, regardless of whether their regurgitation is a result of prolapse (2,3). Several studies concluded that leaflet thickening did not increase one's risk for stroke (2).

Sudden death. Sudden death is a rare complication of MVP. Between 3% and 5% of cardiac-related sudden deaths during exercise are attributed to MVP (7). Several factors have been identified in those who progress to sudden death, including severe mitral regurgitation, severe valve abnormalities without regurgitation, and increased heart weight (1). Reports in the literature also suggest that people with evidence of serious ventricular arrhythmia, those with repolarization abnormalities, and those with convincing clinical symptoms of palpitations and/or syncope may have an increased risk of sudden death (4).

References

  1. Devereux RB: Mitral valve prolapse. J Am Med Wom Assoc 1994;49(6):192-196
  2. Marks AR, Choong CY, Sanfilippo AJ, et al: Identification of high-risk and low-risk subgroups of patients with mitral-valve prolapse. N Engl J Med 1989;320(16):1031-1036
  3. Nishimura RA, McGoon MD, Shub C, et al: Echocardiographically documented mitral-valve prolapse; long-term follow-up of 237 patients. N Engl J Med 1985;313(21):1305-1309
  4. Pocock WA, Bosman CK, Chester E, et al: Sudden death in primary mitral valve prolapse. Am Heart J 1984;107(2): 378-382
  5. Stoddard MF, Prince CR, Dillon S, et al: Exercise-induced mitral regurgitation is a predictor of morbid events in subjects with mitral valve prolapse. J Am Col Cardiol 1995;25(3):693-699
  6. Cheitlin M, Douglas PS, Parmley WW: Acquired valvular heart disease. Med Sci Sports Exerc 1994; 26(10 suppl): S254-S260
  7. Johnson RJ: Sudden death during exercise: a cruel turn of events. Postgrad Med 1992;92(2):195-206

References

  1. Savage DD, Garrison RJ, Devereux RB, et al: Mitral valve prolapse in the general population. 1. Epidemiologic features: the Framingham Study. Am Heart J 1983;106(3):571-576
  2. Maron BJ, Isner JM, McKenna WJ: 26th Bethesda Conference: recommendations for determining eligibility for competition in athletes with cardiovascular abnormalities. Task force 3: hypertrophic cardiomyopathy, myocarditis, and other myopericardial diseases and mitral valve prolapse. Med Sci Sports Exerc 1994;26(10 suppl):S261-S267
  3. Devereux RB: Mitral valve prolapse. J Am Med Wom Assoc 1994;49(6):192-196
  4. Boudoulas H, Kolibash AJ Jr, Baker P, et al: Mitral valve prolapse and the mitral valve prolapse syndrome: a diagnostic classification and pathogenesis of symptoms. Am Heart J 1989;118(4):796-818
  5. Styres KS: The phenomenon of dysautonomia and mitral valve prolapse. J Am Acad Nurse Pract 1994;6(1):11-15
  6. Marks AR, Choong CY, Sanfilippo AJ, et al: Identification of high-risk and low-risk subgroups of patients with mitral-valve prolapse. N Engl J Med 1989;320(16):1031-1036
  7. Nishimura RA, McGoon MD, Shub C, et al: Echocardiographically documented mitral-valve prolapse; long-term follow-up of 237 patients. N Engl J Med 1985;313(21):1305-1309
  8. Stoddard MF, Prince CR, Dillon S, et al: Exercise-induced mitral regurgitation is a predictor of morbid events in subjects with mitral valve prolapse. J Am Col Cardiol 1995;25(3):693-699
  9. Scordo KA: Effects of aerobic exercise training on symptomatic women with mitral valve prolapse. Am J Cardiol 1991;67(9):863-868
  10. Cheitlin M, Douglas PS, Parmley WW: 26th Bethesda Conference: recommendations for determining eligibility for competition in athletes with cardiovascular abnormalities. Task force 2: acquired valvular heart disease. Med Sci Sports Exerc 1994;26(10 suppl): S254-S260
  11. Mitchell JH, Haskell WL, Raven PB: 26th Bethesda Conference: recommendations for determining eligibility for competition in athletes with cardiovascular abnormalities. Classification of sports. Med Sci Sports Exerc 1994;26(10 suppl):S242-S245

Dr Joy is a family physician in private practice in Salt Lake City and a fellow of the American College of Sports Medicine. Address correspondence to Elizabeth Joy, MD, 2295 Foothill Dr, Salt Lake City, UT 84109.


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