II. Causes
- Rheumatic Fever
- Congenital Mitral Stenosis
III. Pathophysiology
- Increased left atrial pressure
- Pulmonary Vasoconstriction
- Pulmonary Hypertension
- Right Ventricular Failure
- Decreased Cardiac Output
IV. Symptoms
- Symptoms of Left Ventricular Failure
- Symptoms of Right Ventricular Failure
- Other Symptoms
- Precipitating Factors
- Exertion
- Fever
- Anemia
- Pregnancy
- Sexual intercourse
- Atrial Fibrillation
V. Signs: Precordial Exam
- Diastolic Thrill
-
Diastolic Murmur at apex
- Apical, low pitched rumbling in mid-diastole
- Loudest in early diastole
- Crescendo at end of diastole (presystolic)
- Accentuating factors
- Left lateral decubitus position
- Stethoscope bell
- Brief Exercise (e.g. brief walk in hallway)
- Opening snap of mitral valve cusp
- Heard at 3rd - 4th interspace at left sternal border
- Accentuated P2 heart sound
- Accentuated M1 heart sound
- Diminished M2 heart sound
VI. Signs: Later findings of Right Ventricular Failure
VII. Complications
- Hemoptysis
- Pulmonary Embolism
- Pulmonary infection
- Systemic emboli
- Endocarditis (uncommon)
VIII. Electrocardiogram
-
Atrial Fibrillation
- Occurs secondary to severe atrial hypertrophy
- Most common complication of Mitral Stenosis
- High risk for Thromboembolism (esp. Cerebrovascular Accident)
- Left atrial enlargement
- Stenosed mitral valve impedes flow from left atrium to left ventricle
- Signs Pulmonary Hypertension
IX. Imaging
-
Chest XRay
- Left atrial enlargement
- Right Ventricular Enlargement
- Posterior displacement of esophagus
- Mitral valve calcification
- Kerley B Lines
-
Echocardiogram (Study of choice)
- Mitral valve leaflet changes
- Inadequate separation of valve leaflets
- Valve leaflet calcification and thickening
- Doppler estimates transvalvular gradient
- Mitral valve leaflet changes
X. Course
- Slow, progressive, life-long course
- Latent period of 20 to 40 years after Rheumatic Fever
- Rapid acceleration of symptoms in later life
XI. Management
-
Rheumatic Fever prophylaxis until age 35 years
- Benzathine Penicillin G 1.2 MU IM qMonth OR
- Penicillin VK 125-250 mg PO bid
- SBE Prophylaxis
- Treat complications and associated conditions
- Atrial Fibrillation
- Congestive Heart Failure
- Anticoagulation for history of emboli
- Surgery
- Open Mitral valvuloplasty Indications
- Mitral orifice <= 1.2 cm2
- Cardiopulmonary symptoms
- Not a candidate for balloon valvotomy
- Percutaneous balloon valvuloplasty (Valvotomy)
- Indications
- NYHA Class II, III, IV moderate Mitral Stenosis
- Contraindications
- Non-pliable or calcified valve
- Subvalvular distortion
- No significant Mitral Regurgitation
- Indications
- Open Mitral valvuloplasty Indications
XII. References
- Kondos (1998) CMEA Medicine Review Lecture, San Diego
- Assi (1998) Postgrad Med 104(6):99-110 [PubMed]
- Bonow (1998) Circulation 98:1949-84 [PubMed]
- Carabello (1997) N Engl J Med 337(1):32-41 [PubMed]
- Shipton (2001) Am Fam Physician 63(11):2201-8 [PubMed]