Diagnosis

Mitral regurgitation

Etiology

Cause [shs]

• Primary mitral regurgitation:

  1. Degenerative

     • Structural deformity/damage to the leaflets, chordae, or papillary muscles

     • Insufficiently closure during systole

     • Causes: Papillary muscle rupture, mitral valve prolapse, or leaflet perforation

  2. Infectious/rheumatic

  3. Congenital valvular anomaly (extremely rare)

• Secondary mitral regurgitation

  1. Functional or ischemic

     • Left ventricular wall motion abnormalities

     • Causes: ischemic cardiomyopathy, remodeling (dilated cardiomyopathy, hypertrophic cardiomyopathy), Atrial fibrillation

Pathophysiology [ysq][8oc]

1. Acute due to spontaneous rupture of the chordae tendineae or papillary muscle: elevated left atrial pressure, acute pulmonary edema, dyspnea, cardiogenic shock (operative mortality 80%)

   • Myxomatous degeneration: Mitral valve prolapse, Ehlers-Danlos, Marfan

   • Myocardial infarction

   • Endocarditis: Abscess, Vegetations, Rupture of chordae, Leaflet perforation

   • Trauma

   • Osteogenesis imperfecta

   • Systemic lupus erythematosus 

2. Chronic decompensated: left ventricular hypertrophy, increased end-diastolic volumes, left ventricular muscle dysfunction, impaired end-systolic ventricle emptying, increased left atrial pressure, pulmonary congestion, left atrial enlargement --> atrial fibrillation, chest pain, arrhythmias, heart failure, pulmonary edema, cardiogenic shock

   • Myxomatous degeneration: Mitral valve prolapse, Ehlers-Danlos, Marfan

   • Mitral annular calcification

   • Annular dilatation and poor valve closure due to left ventricular dilatation

   • Rheumatic heart disease

   • Endocarditis

   • Cardiomyopathy

   • Systemic lupus erythematosus

   • Scleroderma

   • Hypertrophic cardiomyopathy

   • Prosthetic leak

   • Congenital: mitral valve clefts, mitral valve fenestrations, parachute abnormality

   • Drugs: ergotamine, methysergide, pergolide, anorexiant medications

3. Chronic compensated: Left atrium and ventricle have sufficient time to dilate and accommodate the regurgitant volume

Complications [shs]

• Heart failure and related symptoms (ie, shortness of breath)

• Atrial fibrillation

• Stroke due to arrhythmias 

• Pulmonary artery hypertension 

• Dilation of the heart and cardiomegaly 

• Complications of mitral valve surgery:

  Infections, bleeding, clotting/stenosis, valve dysfunction, arrhythmia, stroke, death

Epidemiology

Incidence per 100.000 [p9b][vik]

Prevalence per 100.000 [p9b][vik]

Approach

• Blood test: Troponin T, CK-MB, proBNP [ysq]

• ECG: Atrial fibrillation, Q wave, ST- and T-wave changes

• Chest X-ray: LV and LA enlargement

• Echocardiography: Regurgitation

• Cardiac angiography: assessment of the regurgitant volume (severity)

• Cardiac MRI

Treatment

1. Medication: [ysq][shs]

   • Delay the progression in asymptomatic patients:

     • Angiotensin-converting enzyme inhibitors

     • Angiotensin II receptor blockers

   • After load reduction decreases the regurgitant volume

     • Loop diuretics

     • Vasodilator (nitroprusside)

     • Aortic balloon counterpulsation

   • Pulmonary edema: Oxygen, diuretics, nitrates, intubation

   • Frequency: Moderate tachycardia is beneficial --> less time for regurgitation

   • Rapid atrial fibrillation: Diltiazem, digoxin, cardioversion

   • Heart failure: Diltiazem

2. Percutaneous mitral valve repair

3. Surgical mitral valve repair: if treated early

4. Surgical valve replacement

Differential diagnoses

Aortic regurgitation, Aortic stenosis, Arrhythmia, Cardiac tamponade, Endocarditis, Heart failure, Mitral stenosis, Myocardial infarction, Myocarditis, Pneumothorax, Pulmonary embolism, Shock, Thyrotoxicosis, Tricuspid stenosis