MITRAL VALVE DISEASE Flashcards
What is the single most common cause of valvular disease in the developing world?
Rheumatic fever
What is the underlying mechanism of rheumatic fever?
Occurs 2-3 weeks after a pharyneal infection involving Strep pyogenes - group A streptococcal. Antibody mediated autoimmune response (antibodies against bacteria cross react with membrane antigens. Causes multi-organ disease.
How is the diagnosis of rheumatic fever made?
Duckett-Jones criteria:
Evidence for β-haemolytic streptococcus plus one major criterion or two minor criterion.
What are the major criteria of the Duckett-Jones criteria for diagnosing rheumatic fever?
Carditis
Arthritis
Sydenham’s chorea (involuntary movements of face and mouth due to inflammation of caudate nucleus)
Erythema marginatum (rash with raised red edges)
Nodules
What are the minor criteria of the Duckett-Jones criteria for diagnosing rheumatic fever?
Fever Previous rheumatic fever Raised ESR or Raised CRP Long PR interval Arthralgia
What investigations would you carry out on someone with suspected rheumatic fever?
Blood tests - Raised ESR and CRP
Antistrptolysin O (ASO) titre - rising when taken tow weeks apart
Throat swab - positive
How is someone with diagnosed rheumatic fever managed?
High dose benzylpenicillin.
Anti-inflammatory agents - salicylates
Corticosteroids if signs of carditis
Long term follow up
What is the most common cause of mitral stenosis across the world?
Rheumatic fever
Apart from rheumatic fever, what are the rarer causes of mitral stenosis?
Congenital - isolated lesion Atrial septal defect (Lutembacher's syndrome) Malignant - carnoid Calcification SLE Infective endocraditis
What are the heart conditions that mimic mitral stenosis by obstructing inflow to the left ventricle?
Atrial myxoma (benign tumour of the heart)
Left atrial thrombus
Hypertrophic cardiomyopathy
What are the complications that can arise as a result of mitral stenosis?
Pulmonary hypertension and oedema
Chest infections
Atrial fibrillation
Left atrial enlargement
What are the clinical features of mitral stenosis?
Dyspnoea from pulmonary oedema
Haemoptysis from ruptured pulmonary vein due to hypertension
Palpitations and systemic emboli as a result of AF
Hoarse voice due to enlarged atrium stretching laryngeal nerve
Dysphagia due to enlarged atrium compressing oesophagus
Left lung collapse due to compression of left main bronchus
On examination of a patient with mitral stenosis, what might you expect to find?
Mid-diastolic murmur heard best with patient on their left side in expiration.
Loud S1 - mitral valve slamming shut at beginning of ventricle systole
Tapping apex beat - not displaced
Opening snap after S2
Loud P2 if there is pulmonary hypertension
What investigations would be ordered for someone with suspected mitral stenosis?
ECG
Chest X-ray
Echo
Cardiac catheterization
What might you see on the ECG of a patient with mitral stenosis?
AF
P mitrale - abnormally long p wave in lead II which may have an ‘M’ shape
What might a chest x-ray reveal in someone with mitral stenosis?
Enlarged left atrium
Calcified mitral valve
Prominent pulmonary vessels
What are the medical management options for someone diagnosed with mitral stenosis?
Small dose of beta blocker - allows for slightly longer diastolic filling time
Warfarin - in those with AF and mitral stenosis
Digoxin, beta-blockers or DC cardioversion to treat AF
Diuretics to treat any pulmonary or peripheral oedema
Apart from medical management, what are the management options for someone diagnosed with mitral stenosis?
Mitral valvuloplasty - using a balloon to stretch stenosed valve
Open or closed mitral valvotomy
Mitral valve replacement
What are the four parts of the mitral valve which can become abnormal and render the valve incompetent?
Valve annulus
Valve leaflets
Chordea tendineae
Papillary muscle function
What are the cardiac complications of mitral regurgitation?
Dilatation of left ventricle - leading to left ventricular failure
Right ventricular failure due to pulmonary hypertension
What are the normal presenting complaints of chronic mitral regurgitation?
Fatigue
Dyspnoea
How does acute mitral regurgitation present?
Severe dyspnoea
Which patients are particularly susceptible to acute mitral regurgitation?
MI patients
Infective endocarditis patients
How can an MI lead to mitral regurgitation?
Ischaemic damage leads to papillary muscle rupture or dysfunction
How long after an MI does papillary muscle rupture usually occur?
4-7 days
What pathologies of the mitral annulus might lead to mitral regurgitation?
Senile calcification
Left ventricular dilatation and enlargement of the annulus
Abscess formation during infective endocarditis
What pathologies of the mitral valve leaflets might lead to mitral regurgitation?
Infective endocarditis Rheumatic fever Prolapsing mitral valve (floppy) Congenital malformation Connective tissue disorders - Marfan's syndrome, Ehlers-Danlos syndrome, osteogenesis imperfecta, pseudoxanthoma elasticium
What pathologies of the chordae tendinae might lead to mitral regurgitation?
Idiopathic rupture
Myxomatous degeneration
Infective endocarditis
Connective tissue disorders - Marfan’s syndrome, Ehlers-Danlos syndrome, osteogenesis imperfecta, pseudoxanthoma elasticium
What pathologies of the papillary muscle might lead to mitral regurgitation?
Myocardial infarction
Infiltration - sarcoid, amyloid
Myocarditis
On examination of someone with mitral regurgitation, what signs might you find?
Pan-systolic murmur best heard at apex Irregularly irregular pulse - AF Raised JVP Displaced apex beat Third heart sound Loud P2 Inspiratory crepitations Ascites Peripheral oedema Ventricular heave
What is mitral valve prolapse?
When the valve prolapse back into the atrium.
Does mitral valve affect more males or females?
Females
How do patients with mitral valve prolapse present?
Often with no symptoms (diagnosed at routine medical exam)
Fatigue
Atypical chest pain
Palpitations
Do all patients with mitral valve prolapse need prophylaxis against infective endocarditis?
No, only those with mitral regurgitation
What investigations should be done in someone with suspected mitral regurgitation?
ECG
Chest X-ray
Echo
Cardiac catheterisation
What might an ECG of someone with mitral regurgitation reveal?
Atrial fibrillation
Left-ventricular hypertrophy
What might a chest x-ray of someone with mitral regurgation show?
Cardiomegaly
Calcified valve
Why do we do cardiac catheterisation in patients with mitral regurgitation?
Most patients have minimal MR on echo and do not require catheterisation. It is performed to assess the severity of MR and to exclude valve lesions and coronary artery disease.
How would you medically manage someone diagnosed with mitral regurgitation?
Diuretics and ACE inhibitors to treat congestive cardiac failure.
How might you surgically manage someone diagnosed with mitral regurgitation?
Mitral valve repair (annuplasty or leaflet repair)
Mitral valve replacement
