Mitral Regurgitation Clinical Presentation

Updated: Jan 03, 2016
  • Author: Ivan Hanson, MD; Chief Editor: Richard A Lange, MD, MBA  more...
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Presentation

History

Acute mitral regurgitation

When associated with coronary artery disease and acute myocardial infarction (typically, inferior myocardial infarction, which may lead to papillary muscle dysfunction), significant acute mitral regurgitation (MR) is accompanied by symptoms of impaired LV function, such as dyspnea, fatigue, and orthopnea. In these cases, pulmonary edema is often the initial manifestation because of rapid volume overload on the left atrium and the pulmonary venous system.

Chronic mitral regurgitation

Chronic MR often results from a primary defect of the mitral valve apparatus with subsequent progressive enlargement of the left atrium and ventricle. In this state, patients may remain asymptomatic for years. Patients may have normal exercise tolerance until systolic dysfunction of the LV develops, at which point they may experience symptoms of a reduced forward cardiac output (ie, fatigue, dyspnea on exertion, or shortness of breath). With time, patients may feel chest palpitations if atrial fibrillation develops as a result of chronic atrial dilatation.

Patients with LV enlargement and more severe disease eventually progress to symptomatic congestive heart failure with pulmonary congestion and edema. At this stage of LV dilatation, the myocardial dysfunction often becomes irreversible.

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Physical

On palpation, a brisk carotid upstroke and hyperdynamic cardiac impulse may be noted, and a prominent LV filling wave may be present.

On auscultation, S1 may be diminished in acute MR and chronic severe MR with defective valve leaflets, and wide splitting of S2 may occur due to early closure of the aortic valve. S3 may be present due to LV dysfunction or as a result of increased blood flow across the mitral valve. P2 may be accentuated if pulmonary hypertension is present.

If murmurs are present, note and characterize the following features:

  • Quality: Usually high-pitched, blowing
  • Location: Usually best heard over the apex; usually radiates to the left axilla or subscapular region: posterior leaflet dysfunction causes murmur to radiate to the sternum or aortic area, and anterior leaflet dysfunction causes murmur to radiate to the back or top of the head
  • Duration: Usually holosystolic, may be confined to early systole in acute MR, may be confined to late systole in MVP or papillary muscle dysfunction (S 1 will probably be normal in these cases since initial closure of mitral valve cusps is unimpeded, and a midsystolic click preceding murmur is suggestive of MVP)
  • Intensity: Little correlation exists between intensity of murmur and severity of MR; intensity may be diminished in severe MR caused by LV dysfunction, acute myocardial infarction, or periprosthetic valve regurgitation
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Causes

Acute mitral regurgitation

Causes of acute MR include coronary artery disease, infectious endocarditis, valvular surgery, and other conditions.

Coronary artery disease (ischemia or acute myocardial infarction) may result from papillary muscle dysfunction or chordae tendineae dysfunction or rupture. The posteromedial papillary muscle is supplied by the terminal branch of the posterior descending artery and is more vulnerable to ischemic insult than the anterolateral papillary muscle, which is usually supplied by both the left anterior descending and circumflex arteries. Transient ischemia may result in transient MR associated with angina. Myocardial infarction or severe prolonged ischemia produces irreversible papillary muscle dysfunction and scarring.

Infectious endocarditis features include the following:

  • Abscess formation
  • Vegetations
  • Rupture of chordae tendineae
  • Leaflet perforation

Following valvular surgery, acute MR may occur as a result of trauma, percutaneous valvuloplasty, or suture interruption.

Other causes of acute MR include the following:

  • Tumors (most commonly atrial myxoma)
  • Myxomatous degeneration (mitral valve prolapse, Ehlers-Danlos syndrome, Marfan syndrome)
  • Systemic lupus erythematosus (Libman-Sacks lesion)
  • Acute rheumatic fever (Carey Coombs murmur)
  • Acute global left ventricular dysfunction
  • Prosthetic mitral valve dysfunction

Chronic mitral regurgitation

Causes of chronic MR include the following:

  • Rheumatic heart disease
  • Systemic lupus erythematosus
  • Scleroderma
  • Myxomatous degeneration (mitral valve prolapse, Ehlers-Danlos syndrome, Marfan syndrome)
  • Calcification of mitral valve annulus
  • Infective endocarditis (can affect normal, abnormal, or prosthetic mitral valves)
  • Ruptured chordae tendineae (trauma, mitral valve prolapse, endocarditis, spontaneous
  • Functional MR (dilation of mitral valve annulus, anormal tethering of leaflets due to enlargement of LV cavity and stretch of papillary muscles and chordae [dilated cardiomyopathies, aneurysmal dilation of the left ventricle])
  • Hypertrophic cardiomyopathy
  • Systolic anterior motion of the mitral valve
  • Perivalvular prosthetic leak
  • Congenital (mitral valve clefts, mitral valve fenestrations, parachute mitral valve abnormality)
  • Drug-related (ergotamine, methysergide, pergolide, anorexiant medications)
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