Mitral Stenosis

Aetiology

I. Organic:
1. Rheumatic: The most common.
2. Rare causes: SLE & LA myxoma.

II. Functional:
↑↑ blood flow, Carry-Coomb’s & Austin-Flint murmur.

Stages of MS

I. Compansated MS: Asymptomatic MS.
II. Congestive MS: MS with pulmonary congestion.
III. Hypertensive MS: MS with pulmonary hypertension.
IV. MS with RVF.

Complications of MS

1. In the Mitral Valve:
a. Rheumatic activity.
b. Infective endocarditis.
c. Calcification.
2. In the Left Atrium:
a. Atrial dysrhythmias:
- AF, atrial flutter, atrial premature beats & PSVT.
- AF increases the risk of LA thrombosis.
b. Pressure symptoms due to enlarged LA (rare):
- Dysphagia.
- Cough & dyspnoea.
- Hoarseness of voice.
c. Thrombo-embolism: LA thrombus may lead to
- Systemic embolisation: e.g. cereberal & retinal.
- Ball & valve embolus (rare): causes syncope or sudden death.




3. In the lung:
a. Haemoptysis.
b. Pulmonary oedema.
c. Pulmonary infection.
d. Pulmonary embolism: secondary to DVT.
4. In the RV:
a. RVF.
b. Secondary TI.
5. Complications of treatment:
a. Complications of prolonged rest in bed: e.g. DVT.
b. Complications of medical treatment: e.g. diuretics.
c. Complications of balloon dilatation.
d. Complications of surgery.


Clinical Picture of Mitral Stenosis
Symptoms:
1. In mild cases: no symptoms.
2. In congestive cases: symptoms of pulmonary congestion.
3. In hypertensive cases: symptoms of low CO.
4. In late cases with RVF: symptoms of systemic venous congestion.
General Signs:
1. In mild cases: absent.
2. In congestive cases: fine basal crepitations may be present.
3. In hypertensive cases:
- Signs of low CO. - Malar flush. - Giant A wave.
4. In late cases with RVF: signs of systemic venous congestion.
Precordial Examination:

1. In mild & congestive cases:
- The apex is slapping.
- Diastolic thrill.
2. In hypertensive cases & with RVF:
- Signs of RV enlargement.
- Diastolic thrill over the apex.
- Signs of pulmonary hypertension over the second left space:
• Pulsations. • Palpable S2 (Diastolic Shock). • Dullness.


Auscultation:
1. Over the mitral area:
a. Accentuated first HS: Except with
• Associated MI (Double Mitral)
• Calcified mitral valve.
b. Mitral opening snap:
Its presence indicates absence of calcification & absence of MI.
c. Mitral stenotic murmur:
- Timing:
• Mid diastolic presystolic with presystolic accentuation.
• Short presystolic murmur, in mild cases.
• Presystolic accentuation is lost in AF.
- Character: rumbling.
- Site: heard best at or inside the apex.
- Propagation: localised.
- Position: best heared in left lateral position.
2. In hypertensive & RVF: the previous findings plus
Auscultatory findings of pulmonary hypertension:
• Over the pulmonary area:
- Accentuated second heart sound.
- Ejection systolic murmur: functional PS.
- Early diastolic (Graham-Steel) murmur: functional PI.
3. In cases with RVF: the previous findings plus
• Auscultatory findings over the tricuspid area:
- Pansystolic murmur: due to functional TI.
- Ventricular gallop: due to RVF.

Investigations

1. Chest X-ray:
a. In mild cases:
No abnormality.
b. In congestive MS:
• Left atrial enlargement.
• Pulmonary congestion.
c) In hypertensive MS & late cases with RVF:
• Previous findings & RV enlargement.



2. ECG:
a. In mild case:
No abnormality.
b. In congestive MS:
Left atrial enlargement: P mitrale.
c. In hypertensive MS & RVF:
- Left atrial enlargement: P mitrale.
- Right atrial enlargement: P pulmonale.
- Right ventriclular enlargement.
3. Echocardiography & doppler: for diagnosis of
• MS & its severity.
• Associated valvular lesions.
• Chamber enlargement.
• RV dysfunction: decreased ejection fraction.
• Complications: e.g. thrombosis & infective endocarditis.
Tight Mitral Stenosis

• Severe MS indicated for surgery or balloon dilatation.
• Criteria for diagnosis of tight MS are:
1. Clinical features & investigations diagnostic of:
• Congestive MS with dyspnea more than grade II.
• Hypertensive MS.
• MS with RVF.
2. Echocardiography:
The valve area is less than 1 cm².


Staging of Mitral Stenosis

	I	II	III	IV
Symptoms	• No symptoms	• Pulmonary congestion.	• Pulmonary cong. ↓↓ • ↓↓CO.	• Systemic congestion
General signs	• No signs	• ? crepitations	• Malar flush • ↓↓CO • Giant (A) wave.	• Systemic congestion
Precordial exam	• Slapping apex • Diastolic thrill	• Slapping apex • Diastolic thrill	• Pulm.hypertension • R.V. ↑↑	• Pulm hypertension • R.V. ↑↑↑↑
Auscultation	• ↑↑ S1 • M.O.S • Presystolic murmur	• ↑↑ S1 • M.O.S • Middiastolic, presystolic mur.	• Mitral: same • Pulm: ↑↑ S2 • Tricusp: ↑↑ S4	• Mitral: same • Pulm: same • Tricusp: ↑↑ S3 T.I.
X-ray	• Normal • LA ↑↑	• LA ↑↑ • Pulm. congestion	• Pulm. artery ↑↑ • R.V ↑↑	• Pulm. art. ↑↑ • R.V ↑↑↑↑
ECG	• Normal • P. mitrale	P. mitrale	P. mitrale+ pulmonale R.V ↑	• P. mitrale+ pulmonale • R.V ↑↑↑↑
Echo: Chambers↑↑ M. orifice	• Normal or LA • <4 cm³	• LA • <2 cm³	• LA, PA, RV • <1 cm³	• LA, PA, RV • <1 cm³
Tight M.S.	-	±	+	+
Treatment	Medical	? Med/surg	Surgical	Surgical

Treatment of MS

I. Medical:
1. Prevention of complications:
• Long acting penicillin: to prevent rheumatic activity.
• Antibiotics before surgery: to prevent infective endocarditis.
2. Treatment of complications: e.g.
• HF, AF, Rh activity & Infective endocarditis.
II. Surgical:
Indications:
1. Tight MS.
2. Haemoptysis not responding to medical treatment.
3. Embolisation with no residual manifestations.
Type of Operations:
1. Mitral commissurotomy: in pure MS with no calcification.
2. Valve replacement: if there is calcification or MI.
Complications:
1. Embolisation.
2. Arrhythmias.
3. MI or re-stensosis.
4. Chest infection.
5. Post-cardiotomy syndrome:
• Pleuropericarditis 1-4 weeks after operation.
• Probably immunological.
• It is treated by corticosteroids.
6. Complications of artificial valves:
• Haemolytic anaemia.
• Thrombo-embolism.
• Infective endocarditis.
• Mechanical dysfunction.
• Complications of anticoagulants.
III. Balloon dilatation:
Can replace surgery in patients indicated for valvotomy.