Diagnosis

Mitral stenosis

Etiology

Causes [dh6]

• Rheumatic heart disease --> inflammation --> thickened and calcified mitral leaflets --> commissural fusion in severe cases (younger patients)

• Endocarditis

• Calcific (non-rheumatic) mitral stenosis (older patients)

• Congenital (rare, infancy/early childhood): parachute, double orifice, supra mitral ring, Lutembacher's syndrome)

• Infiltrating disease: mucopolysaccharidosis, amyloid deposition

• Systemic disease: Fabry`s disease, SLE, rheumatoid arthritis

• Postoperative mitral stenosis after mitral valve repair

• Abnormal seretonin metabolism: carcinoid, methysergide)

Pathophysiology [gdm][mts]

1. The bileaflet mitral valve is positioned between the left atrium and left ventricle

2. Opens during diastole to allow blood from the left atrium to the left ventricle

   • Majority of blood filled passively, only a small amount of blood is filled by the atrial contraction (the "atrial kick")

3. Significant mitral valve stenosis: orifice area < 2 square centimeters

   • In case of a pressure gradient, the atrial kick becomes important

4. Mitral valve stenosis --> pressure gradient --> increase in left atrial pressure:

   • Pulmonary hypertension

   • Pulmonary congestion

   • Left atrial dilation --> atrial fibrillation --> loss of the "atrial kick"

   • Decreased cardiac output and heart failure

Risk factors [gok]

• Female sex

• Older age

• Diabetes

• Hypertension

• Coronary artery disease

• Chronic kidney disease

Complications [mts]

• Heart failure

• Stroke

• Failure to thrive

• Pulmonary hypertension

• Endocarditis

Epidemiology

Prevalence per 100.000 [4dy][dh6][dsy][ks8]

Incidence per 100.000 [4dy][dh6][dsy][ks8]

Approach

• Blood test: proBNP

• ECG

• Chest X-ray

• Echocardiography

• Cardiac catheterisation

• CT

Treatment

1. Prophylaxis: [mts]

   • Endocarditis

   • Rheumatic fever

2. Medications: [dh6]

   • Therapeutic bradycardia and treat atrial fibrillation -> Betablocker

   • Treat hypertension --> calcium channel blocker, diuretics

   • Correct anemia, fever, infection and volume overload

   • Risk of embolism --> Anticoagulation

3. Surgery: [dh6]

   • Percutaneous balloon valvuplasty

   • Closed or open valvotomy (reconstruction of the valves)

   • Mitral valve replacement

Differential diagnoses

Aortic regurgitation, Aortic stenosis, Endocarditis, Heart failure, Mitral regurgitation, Myxoma, Rheumatic fever, Tricuspid stenosis