Cardiology: Mitral Regurgitation
Causes – rule of two’s
- Heart
- LV dilatation
- Annular Calcification
- Infective
- Infective Endocarditis
- Rheumatic Heart Fever
- Connective Tissue Disorders
- Marfan Syndroms
- Ehlers-Danlos Syndrome
- Appetite Suppressants
Signs
- Pansystolic murmur best heard in the mitral area, radiating to the axilla.
- Heave
- Displaced Apex Beat
- Possible signs of:
- Heart failure / pulmonary hypertension: crackles at the lung bases, pink frothy sputum, oedema etc
- AF – irregularly irregular pulse
Hang on a minute! – the blood in mitral regurg is flowing away from the axilla – why does the sound radiate to the axilla?
- Well, the sound comes from the valve itself, and is not related to the direction of flow of blood. Due to the location of the mitral valve, any sound it produces (whether from regurg or stenosis) will radiate to the axilla.
Symptoms
- Signs of any valve defect
- Fatigue
- Dyspnoea
Investigations
- ECG – P Mitrale – ‘bifid’ (two-peaks) P waves due to atrial hypertrophy
- Trans-Oesophageal Ultrasound – TOE – used to asses the level of valve damage, to check if suitable for valve repair / replacement
- Doppler-Echo – assesses the site and size of the regurgitant jet
- Cardiac catheterisation – may be used to confirm the diagnosis, and to assess the level of underlying CAD (coronary artery disease)
Management
- Conservative – lifestyle advice (e.g. avoidance of RFs for underlying cause)
- Medical –control the signs and symptoms; e.g. diuretics if heart failure is a component, treat AF
- Surgical –patients may require valve replacement or repair.
- Patients should be placed on antibiotics to prevent bacterial endocarditis
Valve replacements
- Prosthetic – last about 10 years, after which time, may require another replacement. No need for long term anticoagulant therapy.
- Metal –last a life time, but require anticoagulant therapy for life. Also noisy (often make a loud ‘click’ sound). There are three types of metal valve
- Tilting disc
- Double tilting disc
- Ball in a cage
Notes by Tom Leach
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