Mitral stenosis
From Ganfyd
 | History: Digital dilatation of a stenosed mitral valve was the first successful intra-cardiac operation in the UK. It was performed at the London Hospital by Sir Henry Souttar in 1925. References [1] and [2] |
Contents |
Pathophysiology
- Narrowing of the mitral valve results in decreased cardiac output and heart failure
- Back pressure leads to an enlarged left atrium (LA), pulmonary hypertension and the development of atrial fibrillation (AF) which compounds the problem.
Causes
- Idiopathic
- Rheumatic heart disease
- Lutembacher's syndrome where mitral stenosis coexists with an ASD
Signs
- Mitral facies
- Low volume pulse - irregularly irregular if AF
- Loud (tapping) S1 - mitral valve slammed shut by ventricular systole
- Evidence of cardioembolic phenomena (emboli to brain, gut, limbs)
- Dysphagia (enlarged LA presses on oesophagus which lies immediately behind LA)
- Hoarseness (enlarged LA compresses Recurrent laryngeal nerve) Ortner's syndrome
Investigations
CXR
- Enlarged LA shadow
- Pulmonary haemosiderosis
- Pulmonary oedema
ECG
- "M" shaped P wave "P Mitrale"
- Atrial fibrillation
Echocardiography
Management
- Anticoagulate with warfarin to reduce embolic risk
- Try to restore sinus rhythm though difficult with an enlarged LA. If not possible then control ventricular rate with digoxin or other antiarrhythmic
Consider for intervention
- Balloon valvuloplasty - Catheter inserted via femoral vein to the right atrium. Atrial septum pierced to enter left atrium. Balloon manipulated across mitral valve and inflated. Can only be performed where the valve is uncalcified and mobile or there is an increased risk of causing the embolism of valve debris.
- Mitral valve replacement - Open valve replacement with a prosthetic valve
is the definitive treatment
