MITRAL VALVE PROLAPSE
What is mitral valve prolapse?
Mitral valve prolapse (also known as "click murmur syndrome" and "Barlow's syndrome") is the most common heart valve abnormality, affecting five to ten percent of the world population. A normal mitral valve consists of two thin leaflets, located between the left atrium and the left ventricle of the heart. Mitral valve leaflets, shaped like parachutes, are attached to the inner wall of the left ventricle by a series of strings called "chordae." When the ventricles contract, the mitral valve leaflets close snugly, preventing backflow of blood from the left ventricle into the left atrium. When the ventricles relax, the valves open to allow oxygenated blood from the lungs to fill the left ventricle.
Heart and Valves Illustration
In patients with mitral valve prolapse, the mitral apparatus (valve leaflets and chordae) becomes affected by a process called myxomatous degeneration. In myxomatous degeneration, the structural protein, collagen, forms abnormally and causes thickening, enlargement and redundancy of the leaflets and chordae. When the ventricles contract, the redundant leaflets prolapse (flop backwards) into the left atrium, sometimes allowing leakage of blood through the valve opening (mitral regurgitation). When severe, mitral regurgitation can lead to heart failure and abnormal heart rhythms. Most patients are totally unaware of the prolapsing of the mitral valve. Others may experience a number of symptoms discussed below.
The mitral valve prolapse (MVP) syndrome has a strong hereditary tendency, although the exact cause is unknown. Affected family members are often tall, thin, with long arms and fingers, and straight backs. It is seen most commonly in women from 20 to 40 years old, but also occurs in men.
How does a patient with MVP feel?
Most people with MVP have no symptoms. Those who do commonly complain of symptoms such as fatigue, palpitations, chest pain, anxiety, migraine headaches, and even stroke.
Fatigue is the most common complaint, although the reason for fatigue is not understood. Patients with MVP may have imbalances in their autonomic nervous system, which regulates heart rate and breathing. Such imbalances may cause inadequate blood oxygen delivery to the working muscles during exercise, thereby causing fatigue.
Palpitations are sensations of fast or irregular heart beats. In most patients with MVP, palpitations are harmless. In some patients, potentially serious heart rhythm abnormalities may underlie palpitations which require further evaluation and treatment.
Sharp chest pains are reported in some patients with MVP, which can be prolonged. Unlike angina, chest pain with MVP rarely occurs during or after exercise, and may not respond to nitroglycerin.
Anxiety, panic attacks, and depression are associated with MVP. Like fatigue, these symptoms are believed to be related to imbalances of the autonomic nervous system.
Migraine headaches are linked to MVP. They are probably related to abnormal nervous system control of the tension in the blood vessels in the brain.
MVP may be associated with strokes occurring in young patients. These patients appear to have increased blood clotting tendencies due to abnormally sticky blood clotting elements, called platelets.
How is mitral valve prolapse diagnosed and evaluated?
Examination of the patient reveals characteristic findings unique to MVP. Using a stethoscope, a clicking sound is heard soon after the ventricle begins to contract. This clicking is felt to reflect tightening of the abnormal valve leaflets against the pressure load of the left ventricle. If there is associated leakage (regurgitation) of blood through the abnormal valve opening, a "whooshing" sound (murmur) can be heard immediately following the clicking sound.
Echocardiography (ultrasound imaging of the heart) is the most useful test for MVP. Echocardiography can measure the severity of prolapse and the degree of mitral regurgitation. It can also detect areas of infection on the abnormal valves. Valve infection is called endocarditis and is a serious complication of MVP. Echocardiography can also evaluate the effect of prolapse and regurgitation on the functioning of the muscles of the ventricles.
Abnormally rapid or irregular heart rhythms can occur in patients with MVP, causing palpitations. A 24-hour Holter is a continuous cassette recording of the patient's heart rhythm as the patient carries on his/her daily activities. Abnormal rhythms occurring during the test period are captured on tape and analyzed at a later date. If abnormal rhythms do not occur everyday, the Holter recording may fail to capture the abnormal rhythms. These patients then can be fitted with a small "event-recorder" to be worn for one to two weeks. When the patient senses a palpitation, an event button can be pressed to record the heart rhythm prior to, during, and after the palpitation episode. Five events can be recorded before returning the recorder to the doctor's office.
A treadmill test is an electronic recording of the patient's heart during increasing exercise. The treadmill test is useful in detecting heart rhythm abnormalities or lack of oxygen to the heart muscles (ischemia) during exercise. It helps doctors decide which levels of exercise are safe for patients.
What is the treatment for MVP?
The vast majority of patients with MVP have an excellent prognosis and need no treatment. For these individuals, routine examinations including echocardiograms every few years may suffice. Mitral regurgitation in patients with MVP can lead to heart failure, heart enlargement, and abnormal rhythms. Therefore, MVP patients with mitral regurgitation are often evaluated annually. Since valve infection, endocarditis, is a serious complication of MVP, patients with MVP are usually given antibiotics prior to any procedure which can introduce bacteria into the bloodstream. These procedures include routine dental work, minor surgery, and procedures that can traumatize body tissues such as colonoscopy, gynecologic, or urologic examinations. Examples of antibiotics used include oral amoxicillin and erythromycin as well as intramuscular or intravenous ampicillin, gentamycin, and vancomycin.
Patients with severe prolapse, abnormal heart rhythms, fainting spells, significant palpitations, chest pain, and anxiety attacks may need treatment. Beta-blockers, such as atenolol (Tenormin), metoprolol (Lopressor), and propranolol (Inderal), are the drugs of choice. These act by increasing the size of the left ventricle, thereby reducing the degree of prolapse. The calcium blockers verapamil (Calan) and diltiazem (Cardizem) are useful in patients who cannot tolerate beta-blockers.
Although most patients with MVP require no treatment or treatment with oral medications, rare patients need surgery (mitral valve replacement or repair). Patients who require surgery usually have severe mitral regurgitation causing worsening heart failure and progressive heart enlargement. Rarely, rupture of one or more chordae can cause sudden, severe mitral regurgitation and heart failure requiring surgical repair. Mitral valve repair is becoming more popular than mitral valve replacement as the surgical treatment for mitral valve regurgitation. After mitral valve replacement, lifelong blood thinning medications are necessary to prevent blood from clotting on the artificial valves. After mitral valve repair, these blood thinning medications are unnecessary. Because of the success of valve repair, it is being performed earlier in patients with mitral regurgitation, thus reducing the risk of abnormal heart rhythms and heart failure.
Rare patients with MVP may suffer strokes because of increased blood clotting. These patients can be treated with a combination of a blood thinner (anticoagulant) and a beta-blocker.
Again, although patients with MVP may experience a variety of complications, most have no symptoms and can lead healthy, active and normal lives.
Mitral Valve Prolapse At A Glance
* Mitral valve prolapse (MVP) is the most common heart valve abnormality.
* Most patients with MVP have no symptoms and require no treatment.
* MVP can be associated with fatigue and/or palpitations.
* MVP can often be detected by a doctor during examination of the heart. MVP can be confirmed with an echocardiogram.
* Patients with MVP are usually given antibiotics prior to any procedure which might introduce bacteria into the bloodstream, including dental work and minor surgery.
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Background: Mitral valve prolapse (MVP), the most common anomaly of the mitral valve apparatus, occurs when one or both mitral valve leaflets billows excessively into the left atrium towards the end of systole. Mitral regurgitation (MR) occurs in some patients with MVP, particularly with more significant prolapse when the valve edges fail to coapt. An extreme form of prolapse could include chordal rupture, in which the prolapsed mitral valve is flail. Mitral valves excised from patients with severe MR secondary to MVP have large leaflets and show a variety of histologic alterations.
Besides the symptoms attributable to the MR, a variety of neuroendocrine and autonomic disturbances occur in some patients with MVP. In these patients, prolapse may be an epiphenomenon of the underlying autonomic or neurohumoral illness. The term MVP syndrome often is used to refer to the collection of these manifestations. However, in a significant proportion of patients the mitral valve prolapse is trivial, and no such associated manifestations are present. In these patients, MVP constitutes an essentially benign condition.
MVP syndrome was known to physicians as early as 1916, when Sir James MacKenzie described the soldier's heart in spare, thin young men with great vasomotor instability, easy fatigability, breathlessness, and pain over the region of the heart. The syndrome was first described by Kerley in 1920, and by Lincoln in 1928. In 1963, Barlow and colleagues made the first clinical diagnosis of the syndrome as we know it today. The advent of echocardiography led to further advances and formed the basis of our current knowledge.
Idiopathic MVP may be congenital in some patients, but recognition may be delayed until adolescence or adulthood. Associated complicating issues include cardiac arrhythmia, heart failure secondary to severe MR (rare), and occasionally, thromboembolic events. Familial cases are known and occur as an autosomal dominant pattern with variable penetrance and variable expression (familial MVP).
Pathophysiology: MVP is a heterogeneous disorder and may originate from a variety of underlying causes affecting one or more portions of the mitral valve leaflets, chordae tendineae, papillary muscle, and/or valve annulus. The syndrome may occur in isolation or in association with generalized connective tissue abnormalities, such as Marfan and Ehlers-Danlos syndromes, in which specific enzymatic defects are found. It may occur in the context of inflammatory disease such as rheumatic fever or endocarditis. MVP may be secondary to rupture or dysfunction of the papillary muscles following myocardial infarction or ischemia, rupture of chordae tendineae due to infective endocarditis, or abnormal left ventricular wall motion in the setting of myocardial ischemia and/or primary myocardial disease. A connective tissue abnormality, possibly related to collagen metabolism, may underlie the idiopathic disorder.
Electron microscopy of the affected valve leaflets shows a haphazard arrangement, disruption, and fragmentation of collagen fibrils. Myxomatous proliferation of the mitral valve, in which the middle spongiosa layer is involved predominantly, leads to the presence of unusually large amounts of myxomatous material and acid mucopolysaccharide. Degeneration of collagen within the central core of the chordae tendineae may lead to chordal rupture. MVP also can follow rheumatic fever and myocardial infarction, in which case the prolapse is secondary to inflammatory or ischemic chordal rupture, respectively.
Metabolic and neuroendocrine abnormalities also occur in MVP and may result separately in prolapse unrelated to a connective tissue disorder. In such patients, increased norepinephrine and epinephrine may be found. Abnormalities in autonomic and neuroendocrine regulation have been demonstrated, including hyper-response to adrenergic stimulation, parasympathetic abnormalities (vagal withdrawal), altered baroreflex activity, renin-aldosterone regulation abnormalities, decreased intravascular volume, decreased left ventricular volume in upright posture, and atrial natriuretic factor secretion abnormalities.
Frequency:
* In the US: MVP is the most prevalent cardiac valve disorder. MVP is a common finding in otherwise healthy teenagers and young adults, particularly those patients presenting with palpitations, chest pain, or dizziness. More than a third of cases in younger children are associated with other congenital heart defects. Reports vary, but it is likely that 3-5% of pediatric patients have clinically significant MVP.
* Internationally: Prevalence rates are 1-2% in children and 5-15% in adolescents and young adults.
Mortality/Morbidity: When present, coexistent abnormalities dictate the risk. Presence of significant MR and prolonged QT interval on ECG also may influence outcome. QT prolongation is slightly more prevalent among patients with MVP and may be associated with repolarization abnormalities and arrhythmia vulnerability. When severe, MR can lead to heart failure.
Mortality is rare in children. Sudden death also is rare and more often occurs in young women with a history of recurrent syncope, sustained supraventricular tachycardia, or complex ventricular tachycardia. Family history of cardiac sudden death often is a risk-stratifying indicator.
Development of MR and the progression of mild or moderate MR to severe MR are important determinants to morbidity. One study (Deng YB et al) showed that the prevalence of MR increased from 29% of patients to 43% during 4.3 years of follow up. Other possible complications include congestive cardiac failure, rupture of chordae tendineae, infective endocarditis (in 0.1-0.3 cases per 100 patient years), thromboembolic phenomena including cerebrovascular accidents and sudden death. Cardiac arrhythmias such as ventricular tachycardia and fibrillation are more common in MVP.
Sex: Some studies show MVP is twice as frequent in females as in males.
Age: Although findings are more frequent in older children and adults, the defect is believed to be present at birth.
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Physical: Most patients are asymptomatic and MVP is an incidental auscultatory finding. Beta-blockers may markedly attenuate or abolish the symptoms, a fact that is important to remember while evaluating a patient who is receiving these agents. Findings are more marked when patients are examined in the outpatient department rather than in the inpatient setting, reflecting the contributory role of adrenergic state.
* Chest pain occurs in 10% of patients diagnosed with MVP and may be caused by any of the following factors:
o Excessive stretching of the chordae tendineae, leading to traction on papillary muscles
o Coronary microembolism from platelet aggregates and fibrin deposits in the angle between the left atrium and the posterior mitral leaflet
o Inappropriate tachycardia and excessive postural changes and physical and emotional stresses
o Hyperadrenergic state, which increases myocardial oxygen demand
o Coronary artery spasm
* Palpitations
o Palpitations are present in 7.4% of patients.
o Occurrence may be related to cardiac arrhythmia, although this is not proved conclusively.
* Fatigability and dyspnea
o These often develop on exertion.
o The cause may be alterations in centrally modulated breathing cycle control.
* Neuropsychiatric
o Panic attacks may occur.
o Nervousness, presyncope, and syncope occur in 0.9% of patients.
o Thromboembolism, arrhythmia, or vasodepressor-vasovagal problems may be involved.
* Pulse
o Findings usually are normal.
o Pulse occasionally is irregular in the presence of premature contractions.
o Exaggerated tachycardia (high-volume in severe MR) following exertion is not unusual
* Skeletal abnormalities are observed in two thirds of patients. These do not fit into any of the recognized connective tissue disorders, although an occasional patient may have Marfan or other related syndromes. Common findings are as follows:
o Hypomastia
o Thin children
o Height-to-weight ratio greater than normal
o Arm span greater than height (dolichostenomelia)
o Arachnodactyly
o Scoliosis
o Narrow anteroposterior chest diameter (straight back)
o Pectus excavatum or pectus carinatum
o Cathedral palate
o Crowding of teeth
o Joint hypermobility
* Auscultation
o Apical midsystolic nonejection click and late systolic murmur are the hallmarks, but either may occur alone.
o Heart sounds usually are normal, but the first heart sound (S1) may be accentuated when prolapse occurs early in systole, due to the summation of S1 and mitral click.
o Multiple clicks occur when prolapse of different leaflets occurs at different times during the systole and may resemble pericardial friction rub.
o In patients with redundant floppy mitral valves and significant MR, the murmur may be holosystolic and the click absent.
o Where the posterior mitral valve leaflet is prolapsing, the murmur may radiate along the left sternal border to the aortic area, thus mimicking left ventricular outflow tract murmur. If the anterior leaflet prolapses, the murmur radiates to the axilla and the spine.
* Dynamic auscultation
o In the sitting or standing position in late systole, the click may appear earlier and the murmur may be more prominent. The systolic click moves towards S1 on standing, often merging with S1 if marked postural tachycardia occurs, and new clicks may appear. If an exaggerated heart rate response occurs, the murmur becomes longer and often louder to holosystolic. Occasionally the murmur is present only in the upright posture.
o When squatting from standing position, the click and murmur may move back to late systole. Continuous auscultation, while the patient is standing from squatting position, reveals the click and murmur moving back to early systole on a beat-to-beat basis as the heart rate accelerates.
o Occasionally, a systolic precordial honk or whooping sound may be heard with the murmur. Often these are heard only in the sitting or standing position and may be limited to a few beats immediately after standing.
o Dynamic auscultatory changes reflect alterations in the timing of the MVP, the timing and extent of the MR, the expected changes in left ventricular volume, myocardial contractility, and heart rate. In the upright posture, venous return decreases and so does the left ventricular volume. The reflex tachycardia that occurs in the upright position will further reduce left ventricular volume. Timing and degree of the prolapse are determined by the position of the mitral leaflets at end diastole, which in turn is dependent on the distance from the mitral valve annulus to the attachment of the chordae to papillary muscles. Low left ventricular end-diastolic volume shortens the mitral annular papillary muscle distance, allowing the leaflets to prolapse earlier in systole.
o Prompt squatting from standing position increases venous return and left ventricular volume; thus, the systolic click and murmur may become late systolic. Squatting, however, may also be associated with an increase in peripheral vascular resistance, which in turn increases the tension on the mitral valve apparatus, directing blood flow preferentially into the left atrium, rather than to the peripheral circulation. The late systolic click and murmur then become accentuated in the squatting position.
* Other maneuvers are possible as follows, but none is as practical and helpful as a systematically performed postural dynamic auscultation.
o Leg elevation
o Isometric hand grip exercise
o Valsalva maneuver
o Application of tourniquets to the extremities
o Lower body negative pressure or amyl nitrate inhalation
Causes:
* Heritable disorders of connective tissue
o Marfan syndrome
o Ehlers-Danlos syndrome types I, II, IV
o Stickler syndrome
o Polycystic kidney disease, adult type
o Osteogenesis imperfecta
o Fragile X syndrome
o Martin-Bell syndrome
o Pseudoxanthoma elasticum
o Periarteritis nodosa
* Skeletal abnormalities
o Asthenic habitus
o Straight back syndrome
o Pectus excavatum
o Pectus carinatum
o Cardiac abnormalities
o Atrial septal defect (ostium secundum), including atrial septal aneurysm, tricuspid valve prolapse, aortic valve prolapse, and Ebstein anomaly of tricuspid valve
o Holt-Oram syndrome
o Accessory atrioventricular pathways
o Coronary artery anomalies
o Hypertrophic cardiomyopathy
* Other disease
o Graves disease
o Thyroiditis
o Sickle cell disease
o Muscular dystrophy
o Myotonic dystrophy
o Von Willebrand disease
* Several reports suggest magnesium deficiency underlies the disease in some patients.
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Mitral Stenosis, Acquired
Mitral Stenosis, Congenital
Mitral Valve Insufficiency
Other Problems to be Considered:
Congenital mitral regurgitation
Dilated cardiomyopathy
Hypertrophic cardiomyopathy
Rheumatic mitral regurgitation
Tricuspid valve prolapse
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WORKUP Section 5 of 11 Click here to go to the previous section in this topic Click here to go to the top of this page Click here to go to the next section in this topic
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Lab Studies:
* Perform blood and other laboratory tests as dictated by the condition of the patient.
Imaging Studies:
* Radiography
o Chest radiographic findings are normal. Cardiac size and pulmonary venous congestion appear when MR is severe.
o Skeletal surveys detect any abnormalities.
* Echo-Doppler studies
o This is an essential tool to identify the presence and magnitude of MVP, the thickness of mitral valve leaflets, mitral annulus size, chordae tendineae length, and left ventricular and left atrial size and function. The test also reveals any associated heart diseases.
o Multiple views of the mitral valve annulus are essential, and the echo-Doppler findings have to be correlated with clinical data.
o Two-dimensional, real-time echocardiographic pictures from parasternal long axis window show the mitral valve leaflet(s) coming together in systole and billowing into the left atrium beyond the atrioventricular junction. Medial aspect of the anterior and middle scallop of the posterior leaflet are visualized from this view. Lateral scallop of posterior leaflet can be seen only from the apical 4-chamber window, and at times MVP can be focal. The echocardiographic description of the MVP should include structural changes, such as leaflet thickening, redundancy, annular dilatation, and chordal elongation. A varying degree of noncoaptation of the leaflets is present, and MR can be identified by Doppler-color, pulse wave, and continuous wave. The MR jet can be defined and its magnitude and direction estimated. Size of the left atrium and left ventricle are increased in the presence of moderate-to-severe MR.
o M-mode echocardiography shows a characteristic posterior movement of the posterior mitral leaflet during mid or late systole or pansystolic prolapse of both anterior and posterior mitral leaflets towards the left atrium. With the availability of 2-dimensional and Doppler studies, MVP no longer should be diagnosed solely on M-mode pictures.
o These studies, particularly transesophageal echocardiography, also help identify potential embolic sources in those patients with focal neurologic symptoms or signs.
o Findings always are interpreted in the context of the clinical evaluation by dynamic auscultation. The diagnostic accuracy improves by use of a constellation of findings, which include structural as well as functional changes. Patients with echo criteria for MVP, without evidence of thickened redundant leaflets or significant MR, require careful review before MVP is diagnosed. Mere sagging of anterior leaflet in the 4-chamber view does not indicate MVP. Patients with typical auscultatory findings may be diagnosed even with questionable echo findings.
o Rarely, patients with MVP may have typical echo findings but no abnormality on auscultation. The patient with suggestive symptoms and no auscultatory findings, who has nonspecific echo changes, presents a real challenge and may require periodic reevaluation before a firm diagnosis can be made. Family history could be of help in some of these patients.
* Stress scintigraphy: Myocardial perfusion scintigraphy (eg, using thallium-201) during exercise may help identify the rare MVP patient with myocardial ischemia.
Other Tests:
* Electrocardiography
o Results are usually normal, but in about one half of children and adolescents the results may show inverted or biphasic T waves, especially in Leads II, III, aVF, and/or V5-6. The T-wave abnormalities may vary at different times in the same patient and may improve with exercise or with beta-blocker therapy.
o Arrhythmias described at rest or during exercise include premature atrial (23.6%) or ventricular (27.3%) contractions, supraventricular tachycardia, and conduction abnormalities. Patients with MVP demonstrate a higher frequency of left-sided accessory pathways. More serious findings include ventricular tachycardia and fibrillation.
o A higher incidence of arrhythmia may be due to a prolonged QT interval. Diastolic depolarization of muscle fibers in the anterior mitral leaflet in response to stretch also may have a role.
o Slow response action potentials originating in the atrial-like muscle fibers in the mitral valve leaflets could lead to sustained rhythmic action that penetrates the cardiac chambers.
* Phonocardiography: This was previously used as an adjunct to confirm the auscultatory findings.
Procedures:
* Ambulatory 24-hour electrocardiogram
o A Holter monitor may help identify the nature and frequency of arrhythmic activity.
o Usual findings are premature ventricular beats (38%), multiform couplets, and tachyarrhythmias (8%).
* Exercise testing
o This is useful in patients with palpitations and exercise-related symptoms.
o Common findings are premature ventricular beats (16%), ventricular tachycardia (4%), supraventricular ectopy, and rarely, ventricular fibrillation.
* Cardiac catheterization and angiography
o These tests generally are restricted to patients with MVP and severe MR who may require valve repair or replacement.
o Associated coronary artery disease also can be confirmed or excluded.
o A left ventricular angiogram, taken in the right anterior oblique view, best shows the posterior leaflet. A left anterior oblique projection views the anterior leaflet.
o Other abnormalities that may be revealed include dilatation, decreased systolic contraction, calcification of the mitral annulus, and poor contraction of the basal portion of the left ventricle.
* Electrophysiology
o Indications for electrophysiology (EPS) are similar to those in general clinical practice.
o EPS is useful in the presence of supraventricular tachycardia because accessory atrioventricular pathways are common in patients with MVP. In this subset of patients, this becomes important as radiofrequency ablation can be performed during the same procedure, with a very high curative success rate.
* Tilt test: Upright tilt studies with blood pressure and cardiac rhythm monitoring may be valuable in patients with light-headedness or syncope when vasodepressor-vasovagal reaction is suspected and confirmation of clinical symptoms is desired.
Histologic Findings: Mitral valves excised from patients with severe MR secondary to MVP have large leaflets and show a variety of alterations. The most specific, fundamental, and characteristic histologic changes are (1) collagen dissolution and disruption in the pars fibrosa of the mitral valve leaflet and (2) replacement of the dense collagenous fibrosa by loose myxomatous connective tissue with high acid mucopolysaccharide content.
Similar histologic abnormalities are observed in chordae tendineae. Scanning electron photomicrographs demonstrate surface folds and focal loss of endothelial cells on mitral valve leaflets obtained from patients with severe MVP and significant MR. These surface abnormalities may predispose to thromboembolic complications and/or infectious endocarditis. Continuous pressure and stress on the leaflets and chordae tendineae during left ventricular systole contribute to gradual progression of these histologic changes.
TREATMENT Section 6 of 11 Click here to go to the previous section in this topic Click here to go to the top of this page Click here to go to the next section in this topic
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Medical Care: In childhood, the condition is not progressive, and specific therapy is not indicated for the vast majority.
Asymptomatic patients with isolated mitral systolic clicks need only counseling and reassurance.
Avoid excessive use of caffeine, cigarettes, alcohol, and prescription or over-the-counter drugs containing stimulants such as epinephrine or ephedrine, to minimize catecholamine and cyclic adenosine monophosphate (AMP) stimulation.
Prevention of volume depletion before, during, and immediately after exercise may help.
Subacute bacterial endocarditis antibiotic prophylaxis coverage for at-risk procedures is indicated in patients with MVP and MR. Refer to the following table for risk assessment:
Recommendations for Infective Endocarditis Prophylaxis in Children
Instructions: Refer to Table 1 to find out whether patients have a disease that places them at risk for infective endocarditis (IE). If the answer is yes, then go to Table 2 to see if the procedure planned requires antibiotic cover. If the procedure requires prophylaxis, go to Table 3 a or b to select the appropriate antibiotic regimen †.
Table 1. Does the Cardiac Condition Require Prophylaxis?
Prophylaxis RecommendedProphylaxis not Recommended
High riskIsolated ostium secundum ASD (except for 6 months postoperative)
Prosthetic cardiac valves6 months after surgical correction (without residua) of VSD, PDA
Previous infective endocarditisor ASD
Congenital cyanotic heart diseases Previous rheumatic fever without valvular dysfunction
Surgically created systemic to pulmonary artery shuntsPrevious Kawasaki syndrome without valvular dysfunction
Immunosuppression along with an average risk cardiac lesionPrevious coronary artery bypass graft surgery
Average riskMitral valve prolapse without mitral regurgitation
Most congenital cardiac malformations (with exceptions)Physiological, functional or innocent cardiac murmurs
Acquired valvular heart diseases including rheumaticCardiac pacemaker and implanted defibrillator
Mitral valve prolapse with mitral regurgitation
Hypertrophic cardiomyopathy
Table 2. Does the Dental or Surgical Procedure Require Prophylaxis?
ProcedureProphylaxis RecommendedProphylaxis Not Recommended
Dental, oral, respiratory tract or esophageal procedureDental procedure known to induce bleeding, including professional cleaningNatural shedding of primary teeth, orthodontic adjustment, filling above gum line
Tonsillectomy and adenoidectomyTympanostomy tube insertion
Surgery involving respiratory mucosaEndotracheal intubation
Bronchoscopy with rigid bronchoscopeBronchoscopy with flexible bronchoscope
Esophageal stricture dilatationTrans-esophageal echocardiography
Sclerotherapy for esophageal varices
For the above procedures see table 3a
Gastrointestinal or Genitourinary procedure Laparoscopy/CystoscopyGastrointestinal endoscopy with/without biopsy
Urethral dilatationExtra corporeal shock wave lithotripsy of gall bladder stones
Urethral catheterization/urinary tract surgery if urinary infection is presentUrethral catheterization/urinary tract surgery if urinary infection is absent
For the above procedures see table 3bCircumcision
Cardiac proceduresCardiac surgery including systemic to pulmonary artery shunts and implantation of pacemakerCardiac/vascular catheterization
For the above procedures consult a Cardio-Thoracic Surgeon
Other procedures Incision and drainage of infected tissue: consider fluclox 12.5 mg/kg PO 1 h before procedure Incision/biopsy of surgically scrubbed skin
Eye surgery: The publication in this area is lacking; antibiotics may be used to cover procedures with risk of bleeding. Consider amoxicillin or ampicillin regimes given in table 3a.
† Please note the following points:
1. Additional dental care recommended for patients at risk:
* Regular tooth brushing after food or meals.
* No cookies, sweets or sweet drinks between meals.
* Regular dental checks every 6 months.
* Fluoride supplements where drinking water fluoride is less than 0.3 ppm for children younger than 2 years or less than 0.7 ppm for children younger than 2 years.
2. If more than 2 dental treatments are scheduled, they should be at an interval of 14 days or more.
3. Antibiotic prophylactic protection is never absolute. IE should be actively excluded if a patient develops a fever associated with nonspecific symptoms following an "at risk" procedure.
4. When in doubt as to whether antibiotic prophylaxis is required, the risk of IE should be balanced against the immediate risk of an adverse drug reaction, and the long-term development of resistance.
Table 3. What Antibiotic Regimen is Recommended?
A) Dental*, oral, respiratory tract, or esophageal procedures (alpha-hemolytic streptococci)
RegimeModifying ConditionDrugDose, Route, Duration
I) OralUnder local or no anesthesia (includes patients with prosthetic valves)Amoxicillin50 mg/kg PO 1 h before procedure; not to exceed 2 g
Under general anesthesiaAmoxicillin50 mg/kg PO 4 h before procedure; not to exceed 2 g; repeat50 mg/kg PO (not to exceed 2g) as soon as possible after procedure
Allergic to penicillin or received more than one single dose of penicillin in previous monthCephradine OR25 mg/kg PO 1 h before procedure; not to exceed 1 g
Cephalexin OR25 mg/kg (not to exceed 2 g) PO 1 h before procedure; not to exceed 2 g
Clindamycin OR10 mg/kg PO 1 h before procedure; not to exceed 600 mg
Azithromycin / Clarithromycin OR10 mg/kg PO 1 h before procedure; not to exceed 500 mg
Erythromycin ethylsuccinate OR20 mg/kg PO 1 h before procedure; not to exceed 800 mg
Erythromycin stearate20 mg/kg PO 1 h before procedure; not to exceed 1 g
II) ParenteralUnable to take oral medicationAmpicillin50 mg/kg IV 30 min before procedure; not to exceed 2 g
Allergic to penicillin or received more than a single dose of penicillin in previous monthCephradine OR25 mg/kg IV before procedure; not to exceed 1 g
Vancomycin ‡ OR20 mg/kg inf over 1 h, ending 15 min before procedure; not to exceed 1 g
Clindamycin10 mg/kg inf over 10 min given 15 min before procedure; not to exceed 600 mg
*Additional measure for dental procedure only Chlorhexidine gluconate10 ml 0.2% mouth wash OR 1% dental gel before procedure
B) Genitourinary or gastrointestinal (except esophageal procedures (enterococci)
Send urine specimen for culture before urinary procedure; if urinary infection is present, give additional antibiotic cover for the pathogens involved.
RegimeModifying ConditionDrugDose, Route, Duration
III) OralStandard riskAmoxicillin50 mg/kg PO 1 h before procedure; not to exceed 2 g
IV) ParenteralStandard riskAmpicillin50 mg/kg IV before procedure; not to exceed 2 g
Standard risk and allergic to penicillin or received more than a single dose of penicillin in previous monthVancomycin ‡ 20 mg/kg inf over 1 h ending 15 min before procedure not to exceed 1 g)
High riskAmpicillin PLUS Gentamicin 50 mg/kg IV before procedure; not to exceed 2 g; repeat 25 mg/kg (not to exceed 1 g) 6 h later**
2 mg/kg (not to exceed 120 mg) IV before procedure
High risk and allergic to penicillin or Received more than one single dose of penicillin in previous monthVancomycin‡ PLUS Gentamicin 20 mg/kg inf over 1 h ending 15 min before procedure; not to exceed 1 g
2 mg/kg IV before procedure; not to exceed 120 mg
‡ Do not substitute with teicoplanin unless absolutely necessary
** The second dose of ampicillin may be replaced with amoxicillin 25 mg/kg PO not to exceed 1 g
Suggested further reading: (1) Infective endocarditis prophylaxis in children. Hospital Medicine 1998;59:685-689. (2) Prevention of bacterial endocarditis. Recommendations by the American Heart Association. JAMA 1997;277:1794-1801
DT 01/03/99 Venugopalan P & Worthing EA, Sultan Qaboos University Hospital, PO Box 38, PCO 123, Muscat, Sultanate of Oman.
Surgical Care: Consider reconstructive mitral valve surgery for patients with congestive heart failure and/or severe MR secondary to MVP. Readers are referred to the chapter on Mitral Regurgitation for details of surgical intervention, results, postoperative care and complications.
Consultations: A multidisciplinary approach is preferable, with a team from the following specialties:
* Pediatrics
* Pediatric cardiology
* Radiology
* Genetics
* Cardiothoracics
* Physiotherapy
* Family medicine
* Orthopedics
Activity:
* A gradual return to exercise may be tolerated.
* In the absence of studies on the effect of exercise on the progression of MVP, the best approach at present is based on common sense and good clinical judgment.
* Patients with symptoms of syncope, presyncope, or palpitations on exertion should undergo thorough evaluations and avoid competitive sports for at least 6 months after the last significant episode.
* In the presence of significant MR, limitations apply as for any other cause of MR.
* Coexisting aortic root dilatation and aortic regurgitation could limit activity further.
* Patients with cardiac arrhythmia should have periodic exercise tests and ambulatory ECG recordings while doing the type of exercise they are likely to undertake.
* Sudden death is extremely uncommon in MVP.
MEDICATION Section 7 of 11 Click here to go to the previous section in this topic Click here to go to the top of this page Click here to go to the next section in this topic
Author Information Introduction Clinical Differentials Workup Treatment Medication Follow-up Miscellaneous Pictures Bibliography
Medical strategies for MVP
* Anticongestive heart failure therapy
* Antibiotic prophylaxis during surgery and dental procedures - Only necessary if associated mitral regurgitation
* Antiarrhythmic therapy (may be indicated in patients with documented and/or symptomatic arrhythmia, dependent on findings of noninvasive and/or invasive electrophysiologic testing)
* Beta-blockers (may be beneficial for symptom prevention, reduction in ectopy, treatment of vasodepressor syncope, panic attacks, or antiarrhythmic therapy)
* Antiplatelet therapy (in patients with thromboembolic episodes)
* Angiotensin-converting enzyme (ACE) inhibitors (in presence of significant mitral regurgitation)
* Low-dose aspirin and/or anticoagulant therapy; considered in patients with thromboembolic episodes
Drug Category: Beta-adrenergic blocking agents -- Block beta-adrenergic receptor and are modulators of the autonomic system. Inhibit chronotropic, inotropic and vasodilatory responses to beta-adrenergic stimulation.
Drug Name
Propranolol (Inderal) -- Inhibits beta1 and beta2-adrenergic receptors. Class II antiarrhythmic, nonselective, beta-adrenergic receptor blocker with membrane-stabilizing activity that decreases automaticity of contractions.
Adult Dose30-160 mg/d PO divided tid/qid
Pediatric Dose1-4 mg/kg/d PO divided bid/qid
ContraindicationsDocumented hypersensitivity; bronchial asthma, bradycardia, hypotension, second- and third-degree heart block, or severe peripheral arterial disease
InteractionsEnhances hypotensive action of ACE inhibitors, alcohol, anesthetics, corticosteroids, and diuretics; increases negative inotropic action of calcium channel blockers
PregnancyC - Safety for use during pregnancy has not been established.
PrecautionsBeta-adrenergic blockade may decrease signs of acute hypoglycemia and hyperthyroidism; abrupt withdrawal may exacerbate symptoms of hyperthyroidism, including thyroid storm; withdraw drug slowly and monitor closely; reduce dose in liver or renal failure and myasthenia gravis; adverse effects include bradycardia, hypotension, bronchospasm, gastrointestinal upset, fatigue, and rash; taper over 1-2 wk when discontinuing
Drug Category: Antiplatelet agents -- These drugs are used for secondary prevention of thrombotic cerebrovascular or cardiac disease.
Drug Name
Aspirin (Anacin, Bayer, Empirin) -- Inhibits prostaglandin synthesis, which prevents formation of platelet-aggregating thromboxane A2.
Adult Dose75-100 mg/d PO
Pediatric Dose5-10 mg/kg/d PO; not to exceed 100 mg/d
ContraindicationsDocumented hypersensitivity; liver damage, hypoprothrombinemia, vitamin K deficiency, bleeding disorders, asthma; due to association of aspirin with Reye syndrome, not for use in children (<16 y) with flu
InteractionsEffects may decrease with antacids and urinary alkalinizers; corticosteroids decrease salicylate serum levels; additive hypoprothrombinemic effects and increased bleeding time may occur with coadministration of anticoagulants; may antagonize uricosuric effects of probenecid and increase toxicity of phenytoin and valproic acid; doses >2 g/d may potentiate glucose lowering effect of sulfonylurea drugs; enhanced absorption with metoclopramide; increases levels of methotrexate and acetazolamide
PregnancyD - Unsafe in pregnancy
PrecautionsMay cause transient decrease in renal function and aggravate chronic kidney disease; avoid use in patients with severe anemia, with history of blood coagulation defects, or taking anticoagulants; use in pregnancy may cause increased risk of bleeding during delivery; high doses may cause premature closure of ductus arteriosus with complications; enhances risk of kernicterus in babies if given to mother toward term; adverse effects include bronchospasm, gastrointestinal hemorrhage, and other hemorrhages
Drug Name
Dipyridamole (Persantine) -- Acts by decreasing platelet aggregation. Inhibits thrombus formation in the arterial side of circulation.
Adult Dose300-600 mg/d PO divided tid/qid
Pediatric Dose2.5 mg/kg PO bid
ContraindicationsDocumented hypersensitivity; peptic ulcer disease; hereditary coagulopathies
InteractionsTheophylline may decrease hypotensive effects; antiplatelet activity may increase heparin toxicity; enhances and prolongs action of adenosine
PregnancyB - Usually safe but benefits must outweigh the risks.
PrecautionsCaution in hypotension; medication has peripheral vasodilating effects; exacerbates heart failure, asthma, angina, and MI; adverse effects include gastrointestinal upset, dizziness, headache, hot flushes, tachycardia, and bleeding tendency
Drug Category: Diuretics -- These drugs are used to release retained fluid and lower preload.
Drug Name
Furosemide (Lasix) -- Inhibits reabsorption of fluid from ascending limb of the Loop of Henle in renal tubule. Given IV, also has venodilation action, thus also lowering preload even before diuresis effect. Useful in acute heart failure and exacerbations of chronic heart failure.
Adult Dose40 mg PO bid; or 20-50 mg IV, repeat q6-8h
Pediatric Dose1-4 mg/kg PO qd or bid; or 1-4 mg/kg IV q8h
ContraindicationsDocumented hypersensitivity; hepatic coma, anuria, and state of severe electrolyte depletion
InteractionsEnhanced hypotension with ACE inhibitors; enhanced risk of nephrotoxicity with nonsteroidal antiinflammatory drugs; coadministration with amiodarone causes flecainide enhanced toxicity due to the risk of hypokalemia; possible enhanced ototoxicity with aminoglycosides; enhanced hypotension and risk of cardiac arrhythmia with sotalol
PregnancyC - Safety for use during pregnancy has not been established.
PrecautionsPerform frequent serum electrolyte (monitor for hypokalemia and hyponatremia), CO2, glucose, creatinine, uric acid, calcium, and BUN determinations during first few months of therapy and periodically thereafter; aggravates diabetes mellitus, porphyria, and liver failure; caution in pregnancy and breastfeeding
Drug Name
Spironolactone (Aldactone) -- Potassium-sparing diuretic. Acts on the distal convoluted tubule of the kidney as an aldosterone antagonist. Has synergistic action with furosemide.
Adult Dose100-200 mg/d PO
Pediatric Dose0.5-1.5 mg/kg PO bid
ContraindicationsDocumented hypersensitivity; hyperkalemia, hyponatremia, severe renal impairment, Addison disease
InteractionsRisk of hyperkalemia with ACE inhibitors, cyclosporin, or potassium supplements
PregnancyD - Unsafe in pregnancy
PrecautionsCaution in renal and hepatic impairment; may cause gastrointestinal upset, hyponatremia, hyperkalemia, lethargy, confusion, impotence, gynecomastia, and is carcinogenic in rodents
Drug Name
Amiloride (Midamor) -- Pyrazine-carbonyl-guanidine unrelated chemically to other known antikaliuretic or diuretic agents. Potassium-conserving (antikaliuretic) drug that, compared with thiazide diuretics, possesses weak natriuretic, diuretic, and antihypertensive activity. Acts directly on the distal renal tubule, usually used along with a potassium-losing diuretic.
Adult Dose5-10 mg PO bid
Pediatric Dose<20 kg: 0.2 mg/kg PO bid; not to exceed 10 mg/d
>20 kg: Administer as in adults
ContraindicationsDocumented hypersensitivity; elevated serum potassium levels, >5.5 mEq/L; impaired renal function, acute or chronic renal insufficiency, and evidence of diabetic nephropathy; monitor electrolytes closely if there is evidence of renal functional impairment, BUN >30 mg/100 mL or serum creatinine levels >1.5 mg/100 mL
InteractionsRisk of hyperkalemia with ACE inhibitors, cyclosporine, or potassium supplements; decreased effect with NSAIDs
PregnancyB - Usually safe but benefits must outweigh the risks.
PrecautionsPotassium retention associated with use of an antikaliuretic agent accentuated in presence of renal impairment and may result in rapid development of hyperkalemia; monitor serum potassium level, mild hyperkalemia usually not associated with abnormal ECG; gastrointestinal upset, dry mouth, skin rash, confusion, and postural hypotension may occur
Drug Category: Angiotensin-converting enzyme (ACE) inhibitor -- Reduces afterload and decreases myocardial remodeling, which worsens chronic heart failure.
Drug Name
Captopril (Capoten) -- Accepted as essential part of heart failure therapy. Not only gives symptomatic improvement but also prolongs survival.
Adult Dose6.25-25 mg PO tid
Pediatric Dose0.1-1 mg/kg PO tid; initiate at lower dosage range and titrate upward
ContraindicationsDocumented hypersensitivity; renal artery stenosis, left ventricular outflow obstruction
InteractionsNSAIDs may reduce hypotensive effects of captopril; ACE inhibitors may increase digoxin, lithium, and allopurinol levels; rifampin decreases levels; probenecid may increase levels; the hypotensive effects of ACE inhibitors may be enhanced when given concurrently with diuretics;
enhanced hypotensive effect with coadministration of anesthetic agents; cyclosporine enhances risk of hyperkalemia; potassium-sparing diuretics or potassium supplements enhance risk of hyperkalemia
PregnancyC - Safety for use during pregnancy has not been established.
PrecautionsCategory D in second and third trimesters; caution in renal impairment, valvular stenosis, or severe congestive heart failure; adverse effects include hypotension, tachycardia, and renal failure; therapy must be commenced while blood pressure is adequate and state of hydration satisfactory; small doses are started while in hospital and blood pressure monitored; persistent dry cough has been reported in 5-20% of children and it might require change over to another agent in the group or to an angiotensin receptor blocker; other adverse effects include angioedema, rash, serum sickness, GI upset, pancreatitis, hepatitis, cholestatic jaundice, blood dyscrasias, bronchospasm, headache, dizziness, and fatigue
Drug Category: Cardiac glycoside -- Provides symptomatic improvement in heart failure.
Drug Name
Digoxin (Lanoxin) -- Improves myocardial contractility, reduces heart rate, and lowers sympathetic stimulation in chronic heart failure.
Adult DoseMaintenance: 125-250 mcg/d PO
Pediatric DoseMaintenance dose:
Preterm infant: 5-7.5 mcg/kg/d
Term infant: 6-10 mcg/kg/d
1 month to 2 years: 10-15 mcg/kg/d
2-5 years: 7.5-10 mcg/kg/d
5-10 years: 5-10 mcg/kg/d
>10 years: 2.5-5 mcg/kg/d
Daily dose typically divided bid for <10 y
ContraindicationsDocumented hypersensitivity; beriberi heart disease, idiopathic hypertrophic subaortic stenosis, constrictive pericarditis, and Wolff-Parkinson-White syndrome
InteractionsMedications that may increase digoxin levels include alprazolam, benzodiazepines, bepridil, captopril, cyclosporine, propafenone, propantheline, quinidine, diltiazem, aminoglycosides, amiodarone, anticholinergics, diphenoxylate, erythromycin, felodipine, flecainide, furosemide, hydroxychloroquine, itraconazole, nifedipine, omeprazole, quinine, ibuprofen, indomethacin, esmolol, tetracycline, tolbutamide, and verapamil; medications that may decrease serum digoxin levels include aminoglutethimide, antihistamines, cholestyramine, neomycin, penicillamine, aminoglycosides, PO colestipol, hydantoins, hypoglycemic agents, antineoplastic treatment combinations (including carmustine, bleomycin, methotrexate, cytarabine, doxorubicin, cyclophosphamide, vincristine, procarbazine), aluminum or magnesium antacids, rifampin, sucralfate, sulfasalazine, barbiturates, kaolin/pectin, and aminosalicylic acid
PregnancyC - Safety for use during pregnancy has not been established.
PrecautionsReduce dose in renal impairment; avoid hypokalemia; avoid IV use except when absolutely essential; avoid in sick sinus syndrome and thyroid disease; monitor blood level in suspected toxicity and in high-risk situations; major noncardiac adverse effects include vomiting, nausea, abdominal pain, visual disturbances, headache, and fatigue; cardiac adverse effects include arrhythmia (paroxysmal atrial tachycardia with block) and heart block
Drug Category: Antibiotics, prophylactic -- Antibiotic prophylaxis is given to patients with MVP and mitral regurgitation prior to performing procedures that may cause bacteremia. The newest AHA recommendations also include azithromycin and clarithromycin. Adult and pediatric doses for each are 500 mg PO and 15 mg/kg PO 1 h before the procedure respectively.
Drug Name
Amoxicillin (Trimox, Amoxil) -- DOC in most situations. Broad-spectrum penicillin active against certain gram-positive and gram-negative organisms. Compared to ampicillin, it is better absorbed when administered by mouth and produces higher plasma and tissue concentrations.
Adult Dose2 g PO 1 h before procedure
Pediatric Dose50 mg/kg PO 1 h before procedure; not to exceed 2 g
ContraindicationsDocumented hypersensitivity
InteractionsPossible enhanced effect of warfarin; enhances toxicity of methotrexate by reducing its excretion; excretion reduced by probenecid
PregnancyB - Usually safe but benefits must outweigh the risks.
PrecautionsAdverse effects include nausea, vomiting, diarrhea, rash, and rarely, antibiotic-associated colitis; hypersensitivity reactions include urticaria, fever, joint pains, rash, angioedema, anaphylaxis, serum sickness–like reactions, hemolytic anemia, interstitial nephritis, neutropenia, thrombocytopenia, coagulation disorders, and CNS toxicity, including seizures
Drug Name
Ampicillin (Omnipen, Marcillin) -- DOC in patients who cannot tolerate oral medication before procedures (ie, undergoing general anesthesia). Combined with gentamicin in high-risk patients undergoing genitourinary or gastrointestinal (except esophageal) procedures.
Adult Dose2 g IV 30 min before procedure
High-risk patients: 2 g ampicillin IV/IM plus gentamicin 1.5 mg/kg IV 30 min before procedure, followed 6 h later by 1 g ampicillin IV/IM or 1 g amoxicillin PO
Pediatric Dose50 mg/kg IV/IM 30 min before procedure; not to exceed 2 g/dose
High-risk patients: 50 mg/kg IV/IM ampicillin plus gentamicin 1.5 mg/kg IV 30 min before procedure, followed 6 h later by ampicillin 25 mg/kg IV/IM or amoxicillin 25 mg/kg PO
ContraindicationsDocumented hypersensitivity
InteractionsPossible enhanced effect of warfarin; enhances toxicity of methotrexate by reducing its excretion; excretion reduced by probenecid
PregnancyB - Usually safe but benefits must outweigh the risks.
PrecautionsAdverse effects include nausea, vomiting, diarrhea, rash, and rarely, antibiotic-associated colitis; hypersensitivity reactions include urticaria, fever, joint pains, angioedema, anaphylaxis, serum sickness–like reactions, hemolytic anemia, interstitial nephritis, neutropenia, thrombocytopenia, coagulation disorders, and CNS toxicity including seizures
Drug Name
Clindamycin (Cleocin) -- Active against gram-positive organisms including penicillin resistant staphylococci and anaerobes, especially Bacteroides fragilis. Useful in patients with penicillin allergy.
Adult Dose600 mg PO 1 h before procedure
Pediatric Dose20 mg/kg PO 1 h before procedure; not to exceed 600 mg
ContraindicationsDocumented hypersensitivity; regional enteritis, ulcerative colitis, hepatic impairment, antibiotic-associated colitis
InteractionsIncreases duration of neuromuscular blockade, induced by tubocurarine and pancuronium; erythromycin may antagonize effects of clindamycin; antidiarrheals may delay absorption; reduced effect of neostigmine and pyridostigmine
PregnancyB - Usually safe but benefits must outweigh the risks.
PrecautionsDiscontinue immediately if diarrhea develops; associated with severe and possibly fatal colitis; caution with hepatic impairment; no adjustment necessary in renal insufficiency; adverse effects include nausea, vomiting, abdominal discomfort, urticaria, erythema multiforme, dermatitis, cholestatic jaundice, elevated liver enzymes, neutropenia, eosinophilia, agranulocytosis, and thrombocytopenia
Drug Name
Gentamicin (Garamycin) -- Aminoglycoside bactericidal antibiotic effective against some gram-positive and many gram-negative organisms. Has synergistic effect with penicillins against streptococci. Used only in high-risk patients to cover genitourinary or gastrointestinal (except esophageal) procedures.
Adult Dose1.5 mg/kg within 30 min of procedure; not to exceed 120 mg; administer with ampicillin 2 g IV 30 min before procedure
Pediatric Dose1.5 mg/kg IV; not to exceed 120 mg/dose, 30 min before procedure; administer with ampicillin (50 mg/kg IV; not to exceed 2 g/dose)
ContraindicationsDocumented hypersensitivity; non–dialysis-dependent renal insufficiency
InteractionsCoadministration with other aminoglycosides, cephalosporins, penicillins, and amphotericin B may increase nephrotoxicity; aminoglycosides enhance effects of neuromuscular blocking agents thus prolonged respiratory depression may occur; coadministration with loop diuretics may increase auditory toxicity of aminoglycosides; possible irreversible hearing loss of varying degrees may occur (monitor regularly)
PregnancyC - Safety for use during pregnancy has not been established.
PrecautionsNarrow therapeutic index (not intended for long-term therapy); caution in renal failure (not on dialysis), myasthenia gravis, hypocalcemia, and conditions that depress neuromuscular transmission; adjust dose in renal impairment; adverse effects include vestibular and auditory damage, nephrotoxicity, and antibiotic-associated colitis; other adverse effects are nausea, vomiting, and rash
Drug Name
Vancomycin (Vancocin) -- Glycopeptide antibiotic that is bactericidal against aerobic and anaerobic gram-positive organisms. Used in patients allergic to penicillin, who have received more than 1 dose of penicillin in the previous mo, or who are in high-risk category.
Adult Dose1 g IV infusion over 1 h ending 15 min before procedure
Pediatric Dose20 mg/kg (max 1 g) IV infusion over 1 h, ending 15 min before procedure
ContraindicationsDocumented hypersensitivity
InteractionsErythema, histamine-like flushing and anaphylactic reactions may occur when administered with anesthetic agents; taken concurrently with aminoglycosides, risk of nephrotoxicity may increase above that with aminoglycoside monotherapy; effects in neuromuscular blockade may be enhanced, when coadministered with nondepolarizing muscle relaxants; enhanced ototoxicity and nephrotoxicity with cisplatin; enhanced ototoxicity with loop diuretics
PregnancyC - Safety for use during pregnancy has not been established.
PrecautionsCaution in renal impairment; monitor blood counts, urinalysis, and renal function during therapy; avoid using with other nephrotoxic or ototoxic agents; Red Man syndrome (manifested by hypotension, shock, wheezing, dyspnea, urticaria, pruritus, flushing of upper body, and pain and muscle spasm of the back and chest) is caused by too rapid IV infusion (dose given over a few min) but rarely happens when dose given as 2-h administration or as PO or IP administration; Red Man syndrome is not an allergic reaction
Drug Name
Cefazolin (Ancef) -- First-generation semisynthetic cephalosporin that arrests bacterial cell wall synthesis, inhibiting bacterial growth. Primarily active against skin flora, including Staphylococcus aureus. Alternatively, other cephalosporins may be used such as cephalexin (Keflex) or cefadroxil (Duricef). The adult dose for each is 2 g PO and the pediatric dose is 50 mg/kg 1 h before procedure.
Adult Dose1 g IV/IM within 30 min before procedure
Pediatric Dose25 mg/kg IV/IM within 30 min before procedure; not to exceed 1 g/dose
ContraindicationsDocumented hypersensitivity
InteractionsProbenecid prolongs effect; coadministration with aminoglycosides may increase renal toxicity; may yield false-positive urine-dip test results for glucose
PregnancyB - Usually safe but benefits must outweigh the risks.
PrecautionsAdjust dose in renal impairment; superinfections and promotion of nonsusceptible organisms may occur with prolonged use or repeated therapy
FOLLOW-UP Section 8 of 11 Click here to go to the previous section in this topic Click here to go to the top of this page Click here to go to the next section in this topic
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Further Inpatient Care:
* Admission is seldom required, except in the case of complications or for consideration of surgical intervention.
Further Outpatient Care:
* Patients require continued follow-up care and evaluation into adult life.
* Repeat evaluations every 3-5 years to identify any progression.
* Infective endocarditis prophylaxis is indicated in patients with MVP and MR while undergoing at-risk procedures.
* Patients with accessory pathways should have detailed EPS studies and radiofrequency ablation of the accessory pathway.
* Coronary artery anomalies should be excluded in patients with chest pain before they participate in sports.
* Mild prolapse while on echocardiogram, in the absence of clinical findings (15-20% of patients), does not indicate true MVP syndrome. Parents and patients need to be reassured.
In/Out Patient Meds:
* Anti-heart failure medications
* Propranolol
* Aspirin
* Dipyridamole
* Warfarin
* Antibiotics for endocarditis prophylaxis
Complications:
* Progression or appearance of MR is one of the main complications. Over 4.3 years, approximately 14% of patients developed MR.
* Congestive cardiac failure
* Rupture of chordae tendineae
* Infective endocarditis, in 0.1-0.3 cases per 100 patient-years
* Thromboembolic phenomena including cerebrovascular accidents and sudden death
* Cardiac arrhythmia
* Ventricular tachycardia and fibrillation
Prognosis:
* The condition is not progressive in childhood, and specific therapy is not indicated for the vast majority.
* Progression to significant MR or sudden death is rare.
* Asymptomatic patients with isolated mitral systolic clicks need only counseling and reassurance.
Patient Education:
* Careful explanation of the clinical findings and the nature of MVP help to reassure the anxious patient.
* Normal activity can be allowed if mitral regurgitation is not severe
* Antibiotic prophylaxis during surgery and dental procedures is only necessary if associated mitral regurgitation is present.
* The vast majority of patients with MVP remain asymptomatic for their entire lives and require observation every few years for reassurance.
* Patients with orthostatic syncope secondary to dehydration should take extra salt and water during and following sport activities and competition.
* Pregnancy requires infective endocarditis prophylaxis during delivery. Other implications are based on the severity of mitral regurgitation.
* For excellent patient education resources, visit eMedicine's Heart Center. Also, see eMedicine's patient education article Mitral Valve Prolapse.
MISCELLANEOUS Section 9 of 11 Click here to go to the previous section in this topic Click here to go to the top of this page Click here to go to the next section in this topic
Author Information Introduction Clinical Differentials Workup Treatment Medication Follow-up Miscellaneous Pictures Bibliography
Medical/Legal Pitfalls:
* Failure to make the diagnosis
* Failure to fully investigate patients who are symptomatic
* Failure to restrict exercise in patients who are symptomatic
* Failure to recognize the higher risk of arrhythmia durin