Mitral Regurgitation Flashcards
What is mitral regurgitation?
The mitral valve apparatus consists of anterior and posterior leaflets, chordae tendineae, anterolateral and posteromedial papillary muscles, and mitral annulus. Any aberrations of the mitral valve apparatus, due to mechanical, traumatic, infectious, degenerative, congenital, or metabolic causes, may lead to mitral regurgitation (MR).
What are the common causes of acute and chronic mitral regurgitation?
Acute: infective endocarditis, ischaemic papillary muscle dysfunction or rupture, acute rheumatic fever, and acute dilation of the left ventricle due to myocarditis or ischaemia.
Chronic: include those already listed as well as myxomatous degeneration of the mitral leaflets or chordae tendineae and mitral valve prolapse.
What are the risk factors for mitral regurgitation?
- Mitral valve prolapse
- Hx of rheumatic heart disease
- Infective endocarditis
- Hx of cardiac trauma
- Hx of MI
- Hx of congenital heart disease
- Hx of ischaemic heart disease
- Left ventricular systolic dysfunction
- Hypertrophic cardiomyopathy
- Anorectic/dopaminergic drugs
What are the signs of mitral regurgitation?
- Holosystolic, blowing murmur at the apex radiating to axilla
- Displaced hyperdynamic apex
- Soft S1
- Split S2
- Loud P2
What are the symptoms of mitral regurgitation?
- Dysnpoea on exertion
- Decreased exercise tolerance
- Fatigue
- Palpitations
- Lower extremity oedema
What investigations should be ordered for mitral regurgitation?
- Echocardiogram
- ECG
- CXR
- Cardiac catheterisation
Why investigate using echocardiogram?
Visualisation determines severity of valve dysfunction, mechanism, presence of flail, left ventricular size and function, left atrial size, other valvular abnormalities, and right ventricular systolic pressure.
Presence and severity of MR; other structural and flow abnormalities.
Why investigate using ECG?
All patients must undergo ECG examination as a routine screening as well as for any rhythm disturbance (e.g., atrial fibrillation).
May show underlying arrythmia or prior infarction
Why investigate using CXR?
May show enlarged LA and LV, mitral valve calcification and pulmonary oedema.
Why investigate using cardiac catheterisation?
To confirm the diagnosis.
How is acute mitral regurgitation treated?
Surgery is indicated for acute MR. Regurgitation can be corrected by repairing the abnormal valve leaflet or repairing or replacing the supporting valve structures. A prosthetic ring can be inserted to reshape the valve.
Treatment is known as annuloplasty.
What is the medical treatment for mitral regurgitation?
There is no specific accepted medical treatment for chronic management of MR.
All such patients should be treated with ACE inhibitors, beta-blockers, and diuretics.
What are the complications of mitral regurgitation?
- Atrial fibrillation
- Pulmonary hypertension
- LV hypertrophy and congestive HF
What differentials should be considered for mitral regurgitation?
- Acute coronary syndrome (ACS)
- Infective endocarditis
- Mitral stenosis
How does mitral regurgitation and acute coronary syndrome differ?
Differentiating signs and symptoms:
- There may be a history of angina or cardiovascular disease, relief of symptoms with rest or nitrates and risk factors such as family history, smoking, DM, and hyperlipidaemia
- The patient with ACS typically presents with central crushing chest pain lasting >20 minutes, often associated with nausea, sweatiness, dyspnoea and palpitations
Differentiating investigations:
- ECG shows ST segment elevation (in STEMI) or depression (in NSTEMI), tall or inverted T waves or new left bundle branch block
- Cardiac enzymes are raised
