Mitral Valve Prolapse in Emergency Medicine 

Updated: Apr 08, 2021
Author: Michael C Plewa, MD; Chief Editor: Barry E Brenner, MD, PhD, FACEP 

Overview

Background

Mitral valve prolapse (MVP) is generally a benign condition, yet it is also an important contributing risk factor for arrhythmias, endocarditis, stroke,[1] mitral regurgitation (MR), mitral valve replacement (MVR) surgery,[2] and sudden death.[3, 4] Although now considered to be much less common in the general population than previously described,[5, 6] MVP is associated with a multitude of other medical conditions, especially connective tissue disorders, as well as migraine (especially migraine with aura),[7] autoimmune disease,[8] open-angle glaucoma,[9] straight back syndrome (shown in the image below), and idiopathic sudden sensorineural hearing loss.[10]

MVP likely progresses over time, beginning in some instances with "nondiagnostic MVP morphology" (NDM) on echocardiography,[11] and occasionally progressing to MR over decades. Many individuals are asymptomatic, although palpitations, fatigue, and orthostasis are not uncommon, especially when the patient is volume depleted. Symptoms of chest pain, dyspnea, anxiety, and panic[12] are probably no more common with MVP than in the general population.

Mitral valve prolapse. A patient with straight bac Mitral valve prolapse. A patient with straight back syndrome.

Pathophysiology

A myxomatous degeneration from collagen dissolution leads to excess mucopolysaccharides in the middle spongiosa layer of the mitral valve leaflets, resulting in stretching of the leaflets and the chordae tendineae. Mitral valve prolapse (MVP) occurs when the left ventricular (LV) size is small in comparison to an enlarged mitral annulus, leaflets, or chordae tendineae, and it can be induced in healthy women with typical body habitus following dehydration that is reversed with rehydration. Mitral valve prolapse resolves during pregnancy and following weight gain in anorexic patients.

Studies have shown that abnormalities of elastic fibers found in floppy mitral valves are related to genetic variants in fibrillin, one of the components of the microfibrils, as well as elastin and collagen I and II.[13, 4] Mitral valve prolapse is associated with a variety of medical conditions involving connective tissues, such as joint hypermobility disorders,[14] and Ehlers Danlos and Marfan syndromes. Mitral valve prolapse is also associated with autoimmune disorders such as systemic lupus erythematosus and autoimmune thyroid disease; many patients with mitral valve prolapse have positive autoantibodies including ANA, rheumatoid factor, and anticardiolipin antibody.[8]

A constellation of abnormalities (eg, increased sensitivity to adrenergic stimuli, increased catecholamines, abnormal beta-receptors, increased atrial natriuretic factor, renin-aldosterone dysregulation, decreased intravascular volume, magnesium deficiency)[15] has been thought to lead to chest pain, dyspnea, fatigue, dizziness, near-syncope symptoms, and anxiety in a subset of patients with mitral valve prolapse.[16, 17]

Cardiac manifestations include supraventricular more so than ventricular arrhythmias, palpitations, mitral regurgitation, bacterial endocarditis, and sudden death. Chest pain may not be more common in patients with mitral valve prolapse than in the general population, and it may be attributed to myofascial syndromes, hyperventilation, coronary spasm, esophageal dysmotility, or gastroesophageal reflux.[18]

Mitral valve prolapse can result in cerebrovascular ischemia, which may be related to abnormal platelet activity or coagulation disorders (eg, anticardiolipin antibody, protein C or S deficiencies).

Etiology

Most cases of mitral valve prolapse (MVP) are primary, idiopathic in nature, and expressed as an autosomal dominant trait that exhibits both sex- and age-dependent penetrance.[19]

Connective tissue disorders

Connective tissue conditions that may lead to MVP include the following:

  • Marfan syndrome

  • Ehlers-Danlos syndrome (ie, types I, II, IV)

  • Osteogenesis imperfecta

  • Pseudoxanthoma elasticum

  • Polycystic kidney disease

  • Stickler syndrome

  • Systemic lupus erythematosus

  • Relapsing polychondritis

  • Polyarteritis nodosa

Muscle disorders

Duchenne muscular dystrophy, fragile X syndrome, mucopolysaccharidoses, and myotonic dystrophy may lead to the development of MVP.

Heart diseases

Congenital heart disease (eg, atrial septal defect [ASD], Ebstein anomaly, and acquired heart disease (eg, papillary muscle dysfunction [eg, ischemia, myocarditis], cardiac trauma, post mitral valve surgery, rheumatic endocarditis) can cause MVP.

Miscellaneous

Wolff-Parkinson-White syndrome and von Willebrand disease may also lead to MVP.

Epidemiology

United States data

Mitral valve prolapse (MVP) can be identified by echocardiography in an estimated 0.3%[6] to 3% of the general population, and it is identified in 7% of autopsies.[4, 20]

International data

The worldwide incidence of mitral valve prolapse is similar to that in the United States.

Race-, sex-, and age-related demographics

The prevalence of MVP is similar among different ethnic groups.[21]

The female-to-male ratio is approximately 3:1. However, men have a higher risk than women of endocarditis, posterior prolapse, leaflet thickening, severe regurgitation, and men are more likely to undergo mitral valve surgery.[22]

The age of MVP onset is 10-16 years. MVP is uncommon before the adolescent growth spurt occurs, thus, it usually is detected in young adulthood. Although MVP is considered congenital, echocardiographic findings typically are absent in newborns.

Prognosis

Morbidity/mortality

In general, mitral valve prolapse (MVP) is initially a benign disorder, and in most situations, the prognosis is excellent. However, MVP may account for the majority of isolated cases of mitral regurgitation (MR), 90% of cases of ruptured chordae tendineae, 40% of strokes in young patients, and 10-15% of cases of endocarditis.[23]

MR is the most significant risk factor for other complications (eg, sudden death, stroke, endocarditis, atrial and ventricular arrhythmia[24, 25] ). Patients whose echocardiograms shows abnormal valve anatomy, men, and those older than 45 years are at an increased risk of developing MR.

Those with structural abnormalities (ie, thickened, deformed, or redundant mitral valve leaflets) are more likely to suffer complications (eg, progressive MR, endocarditis, sudden death), although a longitudinal study of 285 residents in Olmsted County, MN, suggests that progression of MR occurs in nearly 40% of MVP cases, regardless of age, gender, leaflet thickening, or initial grade of MR.[26]

Left ventricular (LV) remodeling, with elevated LV end-systolic volume index and LV end-systolic dimension, occurs even with isolated late systolic MR murmur similar to that seen with pan-systolic MR murmur.[27]

Patients who are older, lack social support, have higher anxiety, and fail to exercise regularly are at risk for more symptoms.

Cardiovascular mortality is predicted the most by moderate-to-severe MR and ejection fraction less than 50%, and less so by left atrial size greater than 40 mm, flail leaflet, atrial fibrillation, and age older than 50 years.[28, 29]

Cases of MVP with a murmur and not just an isolated click have a general mortality rate that is increased by 15-20%.

Complications

For the following complications, the absolute risk (ie, annual incidence) and the odds ratios (OR), comparing patients with MVP to the general population, are as follows:

  • Sudden cardiac death - 0.06% annual incidence among patients with MVP and severe MR; OR of 50-100 with hemodynamically significant MR and depressed left ventricular function

  • Rupture of chordae tendineae (the most frequent serious complication of MVP)

  • Progressive MR - 0.06% annual incidence of requiring surgery; lifetime risk of surgery is 1.5% for women and 4-6% for men; OR of 30-40; increased risk in males, older than 75 years, elevated body weight, and high blood pressure.

  • Stroke - 0.02% annual incidence versus less than 0.02% in uncomplicated MVP; OR of 4-6

  • Infective endocarditis - 0.02% annual incidence; OR of 3-8; 1 in 1400 patients per year with MVP and murmur; increased risk in males older than 45 years

  • Atrial fibrillation can be persistent in 15% or paroxysmal in 13% when MR is severe enough to require mitral valve replacement (MVR) surgery. These rates are lower than seen with mitral stenosis requiring MVR.[30]

  • Atrial and ventricular arrhythmias are more common in those patients with mitral valve prolapse and moderate-to-severe MR.[24, 25]

  • Individuals with idiopathic sudden sensorineural hearing loss (ISSNHL) have a higher incidence of MVP, mitral leaflet thickening, and MR, suggesting that MVP may be involved in the etiology of this sudden hearing loss.[10]

Patient Education

Patients with a murmur, patients who have echo evidence of nontrivial MR, or men older than 45 years who have valve thickening should inform their dentist and surgeon, although antibiotic prophylaxis prior to dental, respiratory, or infected skin or musculoskeletal tissue procedures would only be indicated if there was a history of infective endocarditis.[31]

Patients with palpitations should avoid caffeine, alcohol, stimulants, and smoking.

Symptoms of the classic mitral valve prolapse (MVP) syndrome may improve with exercise, meditation, and biofeedback.

For patient education resources, see& Heart Health Center, as well as Mitral Valve Prolapse, Chest Pain, and Palpitations.

 

Presentation

History

Mitral valve prolapse (MVP) usually is asymptomatic, nonprogressive, and benign.

Palpitations occur in 40% of MVP cases. This percentage excludes palpitations due to withdrawal syndromes (eg, alcohol, sedatives), intoxications (eg, cocaine, amphetamine, phencyclidine), or medication exposures (eg, caffeine, sympathomimetic, anticholinergic).

Chest pain and dyspnea previously were considered part of the MVP syndrome, but they are now thought to be no more common in cases of MVP than they are in the general population.[5, 32]

Although controversial, anxiety and panic disorders may be more common in patients with MVP than the general population.[33]

Other symptoms may include fatigue, syncope/presyncope,[32] and orthostasis.[32]

Physical Examination

Patients may have the following features:

  • Thin aesthetic body habitus with narrow anteroposterior diameter[34]

  • Skeletal abnormalities (ie, pectus excavatum, straight back, kyphoscoliosis)

  • Supernumerary nipples in Asian Indians

  • Resting bradycardia and orthostatic hypotension

  • Mitral regurgitation[35]

  • Autonomic dysfunction - Decreased heart rate variability and parasympathetic tone[36, 37]

  • Neuroendocrine dysfunction

  • Ehlers-Danlos syndrome findings (eg, joint hypermobility, abnormal striae, bruising, distensibility of skin)

  • Osteogenesis imperfecta findings (eg, blue sclera)

  • Marfan syndrome findings (eg, scoliosis, straight back, pectus excavatum, arachnodactyly, arm span greater than body height)

  • Protrusions of subcutaneous fatty tissue (piezogenic pedal papules) on the lateral feet when standing[38]

  • Stickler syndrome findings (eg, kyphosis, scoliosis, mandibular hypoplasia, retinal detachment). Whether Stickler syndrome is associated with mitral valve prolapse is debatable.

Cardiac auscultation

On cardiac evaluation, the following features may be noted:

  • Apical, single or multiple, mid-to-late systolic clicks, which result from the tightening of the chordae tendineae or the redundant valve, can be heard.

  • An apical mid-to-late systolic murmur of crescendo, decrescendo, or constant nature can be heard, and the murmur continues to be heard in S2.

  • The click and the murmur change as the position changes (closer to S1 with diminished LV volume; closer to S2 with increased LV volume)

  • In the supine position, the click is late (ie, close to S2), and the murmur is brief.

  • In the standing position and during the Valsalva maneuver, the click is earlier (ie, close to S1), and the murmur is longer. This may identify a murmur that previously was not noted.

  • In the squatting position, the click is later (ie, closer to S2), and the murmur is shorter. The click and the murmur may even disappear.

  • The isometric handgrip exercise increases the intensity (ie, loudness) of the murmur without affecting the position.

  • The murmur should be distinguished from that of aortic stenosis (ie, early systolic, at base); pulmonic flow murmur (ie, short and early systolic, diminishes with Valsalva maneuver); hypertrophic cardiomyopathy (ie, diminishes with squatting and intensifies with standing and Valsalva maneuver); and mitral regurgitation (ie, holosystolic murmur with S3, enlarged and displaced point of maximal intensity [PMI]).

 

DDx

Diagnostic Considerations

Important considerations

Evidence of mitral valve prolapse (MVP) should not be a reason to terminate further diagnostic evaluation of patients with symptoms such as chest pain, palpitations, dyspnea, or syncope.

MVP does not predispose women to any increased risk during pregnancy.

Aviators with MVP may develop mitral regurgitation (MR) under positive-G force and may be at risk for dysrhythmia or syncope.

MVP should be considered in the differential diagnosis of patients with unexplained cerebral ischemia.[39]

Patients with MVP and a murmur should avoid high-intensity competitive sports if they have syncope associated with dysrhythmia, a family history of sudden death associated with MVP, significant supraventricular or ventricular dysrhythmias, or moderate-to-severe MR. Those who have had a previous embolic event also should avoid high-intensity competitive sports.

MVP is the third most common cause of sudden death in athletes, following congenital coronary artery anomalies and hypertrophic cardiomyopathy.

Other conditions to consider

Other conditions to consider in patients with suspected mitral stenosis include the following:

  • Hypertrophic cardiomyopathy (HCM)

  • Tachyarrhythmias, narrow complex

  • Tachyarrhythmias, wide complex

  • Ventricular septal defect (VSD)

  • Stickler syndrome

  • Postural orthostatic tachycardia syndrome (POTS)

  • Benign joint hypermobility syndrome

  • Neurocardiogenic syncope

Differential Diagnoses

 

Workup

Laboratory Studies

Specific lab studies are not necessary to confirm mitral valve prolapse (MVP), although some may be indicated to exclude other diagnoses, such as the following.

  • Arterial blood gas (ABG) analysis may be obtained to exclude the diagnosis of hyperventilation, hypoxemia, and metabolic acidosis in patients with tachypnea or dyspnea.

  • Serum electrolytes may be obtained to exclude the diagnosis of hypokalemia and acidosis in patients with dysrhythmias or palpitations.

  • Serum hemoglobin may be obtained to exclude the diagnosis of anemia in patients with fatigue or near-syncope.

  • Serum glucose may be obtained to exclude the diagnosis of hypoglycemia in patients with fatigue or near-syncope.

  • Cardiac enzymes may be obtained to exclude the diagnosis of an acute myocardial event in patients with chest pain.

  • A urine toxin screen may be obtained to exclude the diagnosis of an exposure to amphetamines, cocaine, or phencyclidine in patients with agitation, chest pain, dyspnea, and tachydysrhythmia.

Other Tests

Tilt table testing

Tilt table tests may be more likely to be positive in patients with mitral valve prolapse than in control patients; however, this finding is nonspecific.[40]

Holter monitoring

Outpatient Holter monitoring or transtelephonic event recording should be considered in patients with palpitations that are associated with syncope or near-syncope.

Supraventricular tachydysrhythmias occur in 30% of patients with mitral valve prolapse (MVP), but the incidence of ventricular dysrhythmias is similar to that of the general population.

Electrophysiologic testing

Electrophysiologic testing is indicated for those with near-sudden death, symptomatic complex ventricular ectopy, Wolff-Parkinson-White syndrome, and recurrent unexplained syncope.

Stress testing

Contrary to earlier studies that report a false-positive result 50% of the time on exercise stress ECGs and thallium imaging studies, more recent reports have found stress test abnormalities no more likely in patients with MVP than in the general population.

Chest Radiography

Chest radiography is not specifically indicated except to exclude other causes of chest pain and dyspnea.

The chest radiograph may reveal an increased left atrial or pulmonary artery size, which is indicative of mitral regurgitation. A lateral chest radiograph may reveal dorsal spine straightening and a narrow anteroposterior diameter.

Echocardiography

Outpatient echocardiography (echo) is indicated for those with a murmur.

Although screening subjects who are at a low risk for complications (ie, those without mitral regurgitation [MR]) is not indicated, 2-dimensional and 3-dimensional echocardiography can detect the patients with more severe or unusual forms of mitral valve prolapse (MVP) (eg, patients with significant MR, annular and leaflet thickening, chordal lengthening, atrial septal defect [ie, secundum], hypertrophic cardiomyopathy).[41, 42, 43, 44]

Two-dimensional echocardiography is less sensitive than M-mode echo, detecting only 50% of patients with M-mode echo and auscultatory findings, but it is more specific for MVP than M-mode echo.

Diagnostic criteria include systolic billowing of one or both mitral leaflets by more than 2 mm into the left atrium. This systolic billowing occurs on the left atrial side, above the visualized annular plane, in the long-axis parasternal view. Additionally, parasternal long-axis views demonstrate 5 mm or more of leaflet thickness.

An M-mode echocardiogram gives many false-negative and false-positive results, but it can identify MVP with at least 2 mm of midsystolic prolapse or 3 mm of holosystolic or late-systolic movement of the leaflets, which are posterior to the line connecting the valve's opening and the closure points.

Doppler echocardiography is recommended every 2-3 years for patients with mild MR, and it is recommended yearly for those with significant MR.

Electrocardiography

Electrocardiographic (ECG) findings include the following:

  • Results usually are normal.

  • Minor QTc prolongation (0.42 ± 0.05) may occur.

  • More commonly QTc intervals are normal, yet QT dispersion is elevated.[40, 45] QT dispersion may differentiate between primary mitral valve prolapse (MVP) and rheumatic MVP.[46]

  • Prolonged Tp- interval and Tp-e/QT ratios are higher in patients with MVP, increasing their risk for ventricular arrhythmias.[45]

  • Nonspecific ST- and T-wave changes were previously noted, but they may not be more frequent than in the general population.

Computed Tomography Scanning

Cardiac multidetector computed tomography (MDCT) scanning, more commonly used for the assessment of coronary artery anatomy, also has useful accuracy in assessing mitral valve prolapse (MVP).[47]

Cardiac CT angiography also has good sensitivity and specificity in detecting MVP, defined as a 2-mm displacement of the mitral leaflet below the annulus plane.[48]

Although not commonly used clinically, single-photon emission CT myocardial perfusion imaging has excluded myocardial ischemia in patients with MVP and exercise-induced chest pain.[39]

 

Treatment

Approach Considerations

Consultation by a cardiologist is recommended to confirm the diagnosis of mitral valve prolapse (MVP), to exclude other possible disorders from the diagnosis (eg, hypertrophic cardiomyopathy, atrial septal defect) and to further evaluate symptoms (eg, palpitations).

Echocardiography may not be necessary for diagnosis in many cases because dynamic auscultation may be more reliable.

Cognitive behavioral therapy and breathing retraining may diminish functional cardiac symptoms (eg, chest pain, dyspnea, dizziness).

Follow-up care by a cardiothoracic surgeon is recommended for patients with hemodynamically significant mitral regurgitation (MR). Surgical repair or replacement of the mitral valve is indicated for patients with exertional dyspnea, an ejection fraction below 50%, and a left ventricular end-systolic dimension approaching 45 mm.

Prevention

Blood pressure control may diminish the risk of progression to mitral regurgitation.

Exercise; biofeedback; meditation; and avoidance of smoking, alcohol, caffeine, and stimulants may prevent symptoms.

Prehospital Care

The prehospital treatment of patients with chest pain, dyspnea, palpitations, a neurologic deficit, or syncope should include cardiac monitoring, supplemental oxygen, and intravenous catheter placement.

Emergency Department Care

Patients with symptoms of chest pain, dyspnea, palpitations, a neurologic deficit, or syncope should be placed on oxygen, put in a supine or Fowler position, and monitored with the following:

  • Pulse oximetry

  • Cardiac monitoring

  • Frequent vital signs, including one set of orthostatic vital signs when possible

Anxious patients should be reassured regarding their status, and many may benefit from psychosocial intervention.

Patients with stroke, risk of sudden death, unstable ventricular dysrhythmias, severe symptomatic mitral regurgitation (MR), or bacterial endocarditis may require inpatient management.

Consultations

Consult a cardiologist in cases of diagnostic uncertainty, ventricular dysrhythmia, or risk of sudden death as well as when symptoms of severe MR are present.

Consider consulting a cardiothoracic surgeon in patients with significant exertional dyspnea and congestive heart failure that is related to MR.

 

Medication

Medication Summary

Medications generally are not necessary. Beta-blockers may be helpful if palpitations are severe.

Antiplatelet agents such as aspirin, aspirin with extended-release dipyridamole (Aggrenox), or clopidogrel (Plavix) are indicated for patients with transient ischemic attack or stroke.[49] Some authors recommend prophylaxis with antiplatelet agents in all patients with mitral valve prolapse (MVP) and murmur because of a small but significant increase in risk of stroke (10%).[50]

Orthostatic hypotension and presyncope symptoms may be treated with sodium chloride tablets; however, if this treatment is not successful, fludrocortisone 0.05-0.10 mg/d PO may be used.

Magnesium supplementation may improve symptoms of the classic MVP syndrome.[15]

Significant mitral regurgitation (MR) in the setting of hypertension (systolic blood pressure >140 mm Hg) may be improved with the use of angiotensin-converting enzyme inhibitors. No evidence exists as yet to support the use of these medications to halt the progression of MVP to MR.

Antibiotics

Class Summary

Antibiotic prophylaxis to prevent infective endocarditis is no longer recommended prior to dental or surgical procedures for any patient with MVP (even those with a murmur or nontrivial MR on echo and men older than 45 years with valve thickening) unless there is a history of endocarditis.[31] Antibiotic prophylaxis to prevent infective endocarditis is no longer recommended prior to genitourinary or gastrointestinal procedures, even with a history of endocarditis.[31, 51]

Patients with MVP with prior endocarditis who are undergoing a dental, respiratory tract, infected skin, or musculoskeletal tissue procedure (eg, contaminated wound repair or abscess incision and drainage) should receive prophylaxis for infective endocarditis with amoxicillin 2 g (50 mg/kg) PO 1 hour prior to the procedure. Patients with MVP with prior endocarditis who are unable to take oral medications may be treated with ampicillin 2 g (50 mg/kg) IM or IV, or cefazolin or ceftriaxone 1 g (50 mg/kg) IM or IV 1 hour prior to the procedure.

Patients with MVP with prior endocarditis who are allergic to penicillin may be treated 1 hour before the procedure with cephalexin 2 g (50 mg/kg) PO, clindamycin 600 mg (20 mg/kg) PO, or azithromycin or clarithromycin 500 mg (15 mg/kg) PO. Clindamycin 600 mg (20 mg/kg), or cefazolin or ceftriaxone 1 g (50 mg/kg), may be administered IM or IV 30 minutes before the procedure, as an alternative to the PO route.

Amoxicillin (Amoxil, Biomox, Polymox)

DOC; interferes with the synthesis of cell wall mucopeptide during active multiplication, resulting in a bactericidal activity against susceptible bacteria.

Ampicillin (Marcillin, Omnipen)

Alternative parenteral agent. Interferes with bacterial cell wall synthesis during active multiplication, causing bactericidal activity against susceptible organisms. Given in place of amoxicillin in patients who are unable to take medication orally.

Beta-blockers

Class Summary

Blood pressure control may prevent chordal rupture and the progression of MVP to severe MR. Clonidine has been shown to diminish symptoms of the classic (disputed) MVP syndrome. Beta-blocking agents (eg, propranolol, atenolol, pindolol) may also be effective in those with neurocardiogenic syncope.

Atenolol (Tenormin)

Selectively blocks beta1-receptors with little or no effect on beta2 types.

Antiarrhythmics

Class Summary

Digoxin has been effective in treating supraventricular tachycardia and in the prevention of symptoms of classic MVP syndrome (eg, chest pain, fatigue).

Digoxin (Lanoxin)

Cardiac glycoside with direct inotropic effects in addition to indirect effects on the cardiovascular system. Effects on the myocardium involve both a direct action on cardiac muscle that increases myocardial systolic contractions and indirect actions that result in increased carotid sinus nerve activity and enhanced sympathetic withdrawal for any given increase in mean arterial pressure.