Mitral stenosis

Question 1

What comprises of the Mitral valve

Answer 1

Anterior and Posterior leaflets, chordae tendineae, papillary muscles

Question 2

What is the most common cause of mitral stenosis?

Answer 2

RHD (Group A B-Haemolytic streptococcus)

Question 3

What are the other causes of mitral stenosis?

Answer 3

congenital mitral stenosis, carcinoid tumours, Lutembacher syndrome, mitral annular calcification rare (may lead to mitral stenosis in the elderly patients and those with ESKD)

Question 4

What is the Pathophysiology of Mitral stenosis?

Answer 4

# 4 - 6cm2 is normal but 1cm2 becomes worse
# For sufficient cardiac output, left atrial pressure increase, left atrial dilatation
# consequently, increase in pulmonary venous, pulmonary artery and right heart pressure
# increase in pulmonary pressure is followed by pulmonary edema
# prevented by alveolar thickening and pulmonary arterial vasoconstriction (reactive pulmonary hypertension)
# pulmonary hypertension leads to right ventricular hypertrophy, dilatation and failure with subsequent tricuspid regurgitation.

Question 5

What are the symptoms of Mitral stenosis

Answer 5

1. usually no symptoms until the valve orifice is moderately stenosed <2cm
2. progressive severe dyspnoea (from increased left atrial pressure, vascular congestion and pulmonary edema)
3. cough productive of blood tinged, frothy sputum or frank hemoptysis can occur.
4. pulmonary hypertension leads to right heart failure and its symptoms of weakness, fatigue, abdominal or lower limb swelling.
5. large left atrium predisposes to atrial fibrillation, giving palpitations.

Question 6

What are the signs of mitral stenosis

Answer 6

Face
- mitral facies or malar flush

Pulse

• may be associated with small volume pulse (early in disease process)
• atrial fibrillation resulting in irregularly irregular pulse (as severity of disease progresses)

Jugular veins
- if right heart failure develops, there is obvious distension of the jugular veins

Chest

• left tapping parasternal heave (result of palpable first heart sound combined with left ventricular backward displacement produced by an enlarging right ventricle.
• loud first heart sound if mitral valve pliable, but this will not ocurr in calcific mitral stenosis
• as valve suddenly opens with the force of increased left atrial pressure, an “opening snap” is heard.
• followed by low pitched, ‘rumbling’, mid-diastolic murmur

Question 7

The severity of mitral stenosis is judged clinically by several criteria. some are?

Answer 7

1. Presence of Pulmonary HTN (Pulmonary HTN will result in pulmonary valve regurgitation, which causes an early diastolic murmur in the pulmonary area known as GRAHAM STEELL murmur)
2. The time between the load OS and Second heart sound shortens with increasing severity of mitral stenosis
3. The length of the mid diastolic murmur is proportional to the severity
4. As the valve become immobile, the loud first heart sound softens and the opening snap disappears. when pulmonary HTN occurs, the mid-diastolic murmur becomes quieter because of the reduction in cardiac output.

Question 8

what are the investigations in Mitral stenosis?

Answer 8

Chest Xray (left atrial enlargement with straightening of the left heart border and a ‘double shadow’ on the border of the right and left atria.

ECG shows bifid P wave owing to delayed atrial activation, may show atrial fibrillation, as diseases progresses, ECG features of right ventricular hypertrophy (right axis deviation, tall R waves in lead V1) may develop

TTE (determine left atrial size and degree of thickening, calcification and mobility of mitral leaflets) and TOE (detection presence of left atrial thrombus. Wilkins score assesses whether the valveis suitable for percutaneous vallvotomy)

CMR mitral valve anatomy shown more accurately

Cardiac catheterization may be used to determine pulmonary artery pressure in patients referred for valve intervention.

Question 9

How do you manage Mitral stenosis

Answer 9

1. May need no treatment other than prompt therapy for attacks of bronchitis. infective endocarditis in mitral stenosis is uncommon.
2. Early symptoms of mitral stenosis, such as mild dyspnoea, can be treated with diuretics
3. The onset of Atrial fibrillation may require beta blockers or DC cardioversion and anticoagulation to prevent atrial thrombus and systemic embolization.
4. If pulmonary HTN develops with persistence of symptoms despite therapy, surgical relief of mitral stenosis required.

Question 10

What are the operative measures for Mitral stenosis

Answer 10

1. Trans-septal balloon valvotomy
2. Closed valvotomy
3. Open valvotomy
4. Mitral valve replacement