• Clinical science

Mitral stenosis

Abstract

Mitral stenosis (MS) is a valvular anomaly of the mitral valve that leads to obstruction of blood flow into the left ventricle. The most common cause of MS is rheumatic fever. The clinical manifestations depend on the extent of stenosis: reduced mitral opening leads to progressive congestion behind the stenotic valve. Initial dilation of the left atrium (complications: atrial fibrillations, emboli) is followed by progressive congestion of the lungs and subsequent cardiac asthma (coughing, dyspnea). Acute decompensation can cause pulmonary edema. Echocardiography is the main diagnostic tool for evaluating the mitral valve apparatus, left atrial size, and pulmonary pressure. In the event of high grade and/or symptomatic stenosis, percutaneous valvuloplasty or surgical valve replacement is often required.

Etiology

Pathophysiology

Clinical features

References:[1][2][3]

Diagnostics

  • Auscultation (see auscultation in valvular defects)
    • Diastolic murmur typically heard best at the 5th left intercostal space at the mid-clavicular line (the apex)
      • Heard loudest when the patient is lying on his/her left side.
    • Loud first heart sound (S1)
    • Opening snap of the mitral valve after S2; shorter interval between opening snap and S2 indicative of more severe disease; , because left atrial pressure is greater than left ventricular end diastolic pressure (LVEDP)
  • Chest x-ray
    • Posterior-anterior image
      • LA enlargement with prominent left auricle (left atrial appendage) → straightening of the left cardiac border ; double density sign: double contour of the right atrial border due to the enlarged left atrium overlapping with the right atrium
      • Splaying of the carina > 90°
      • Signs of pulmonary congestion; (see X-ray findings in pulmonary congestion)
    • Lateral image
  • ECG
  • Echocardiography: most important diagnostic method for detecting and assessing valvular abnormalities
    • Abnormal valve mobility
    • Subvalvular thickening
    • Leaflet thickening
    • Calcification
  • Coronary angiography may be conducted prior to surgical interventions to assess the associated risk of coronary artery disease

References:[2][3][4]

Treatment

ACE inhibitors and other afterload-reducing drugs are contraindicated because they cause dilation of peripheral blood vessels, which may lead to cardiovascular decompensation!

Complications

We list the most important complications. The selection is not exhaustive.

  • 1. Jenkins B, McInnis M, Lewis C. Step-Up to USMLE Step 2 CK. Lippincott Williams & Wilkins; 2015.
  • 2. Collier P, Phelan D, Griffin BP. Mitral Valve Disease: Stenosis and Regurgitation. http://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/cardiology/mitral-valve-disease/. Updated August 1, 2014. Accessed February 13, 2017.
  • 3. Dima C. Mitral Stenosis. In: Mitral Stenosis. New York, NY: WebMD. http://emedicine.medscape.com/article/155724-overview. Updated November 6, 2014. Accessed February 26, 2017.
  • 4. Nishimura RA, Otto CM, Bonow RO, et al. 2014 AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2014; 63(22): pp. e57–185. doi: 10.1016/j.jacc.2014.02.536.
  • Herold G. Internal Medicine. Cologne, Germany: Herold G; 2014.
last updated 12/13/2018
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