TOC | Cardiology    * MITRAL STENOSIS                                RX  

Normal mitral valve orifice in adult is 4-6 cm2. Significant flow obstruction occurs when it is <2 cm2. When it is reduced to 1 cm2, a left atrial pressure of about 25 mmHg is required to maintain a normal CO. The elevated atrial pressure will raise pulm venous & capillary pressures, reducing pulm compliance & causing exertional dyspnea.

Dyspnea, pulm edema, atrial arrhythmias, hemoptysis from rupture of pulm-bronchial venous connections secondary to pulm venous hypertension. Right vent.failure, fatigue, abd.discomfort of hepatic congestion.  Recurrent pulm. emboli or infarction. Pulm. infections, infective endocarditis.

a rumbling diastolic murmur at the apex, esp. with the patient lie on the left side and by using provocative maneuvers such as exercise to increase the heart rate.



  1. Prophylaxis for infective endocarditis.
  2. Dietary salt restriction, diuretics, control vent. rate (esp. with atrial fibrillation/flutter) with B-blockers , Calcium blockers or digoxin.
  3. Anticoagulation with warfarin is indicated to prevent thromboembolism when (1) atrial fibrillation is present, (2) there is a history of embolism, or (3) the left atrium is large (> 50 mm in diameter on echocardiography).
  4. Mitral valvulotomy is indicated in symptomatic pt with pure MS whose effective orifice is < 1.3 cm2 (or 0.8 cm2/m2 of body surface area).
  5. Mitral valve replacement in those with critical MS of <1.0 cm2, and in NYHA class III.
  6. Bioprosthesis has less thromboembolic complications, does not need permanent anticoagulation, but may need repeat replacement in 30% of pts in 10 yrs, and in 50% of pts in 15 yrs; not suitable for young pts < 35 yo.
  7. Mechanical prosthesis needs permanent anticoagulation to prevent thromboembolism, but lasts longer.

Scientific American Medicine 1999


Caring for patients with prosthetic heart valves
Cleveland Clinic J of Med  Jan. 2002