Mitral Valve DiseaseProf JD Marx UFSJanuary 2006
Anatomy
Mitral Stenosis
Almost always rheumatic Heavy calcification in elderly Congenital MS in infants
Aetiology
Mitral valve orifice diminished by
progressive fibrosis
calcification valve leaflets
fusion cusps subvalvular apparatus
Pathophysiology
Mitral Valve Orifice Normal 5 cm²
Moderately severe 2 cm² or less
severe 1 cm² or less
Pulmonary venous congestion
LA dilatation and hypertrophy
LA contraction important LV filling
Diastolic filling period important
Pulmonary hypertension
Atrial fibrillation
Thrombus formation in LA
Bloodflow LA to LV restricted
Breathlessness (pulmonary congestion)
Fatigue (low cardiac output)
Oedema, ascites (right heart failure)
Palpitation (atrial fibrillation)
Haemoptysis (pulmonary congestion, pulmonary embolism)
Cough (pulmonary congestion)
Chest pain (pulmonary hypertension)
Symptoms of thromboembolic complications (e.g. stroke, ischaemic limb)
Symptoms
Atrial fibrillation
Mitral facies
AuscultationLoud first heart sound. Opening snapMid-diastolic murmur
Signs of raised pulmonary capillary pressureCrepitations, pulmonary oedema, effusions
Signs of pulmonary hypertensionRV heave, loud P2
Signs
ECG Left atrial hypertrophy (if not in AF) Right ventricular hypertrophy
Chest Radiograph Enlarged left atrium Signs of pulmonary venous congestion
Echo Thickened immobile cusps Reduced valve area Reduced rate of diastolic filling of LV
Doppler Pressure gradient across mitral valve Pulmonary artery pressure
Cardiac catheterisation Pressure gradient between LA (or pulmonary wedge) and LV
Investigations
Medical management
Patients with minor symptoms
Anti coagulants eg Warfarin
Diuretics for pulmonary congestion
Rate and rhythm control digoxin, -blockers etc
A/B prophylaxis IE
Management
Mechanical disease
Consider - patient symptomatic- pulmonary hypertension- atrial fibrillation- MVA 1 cm² or less
Mitral balloon valvuloplasty
Open mitral replacement
Surgical procedures
Mitral Regurgitation
Aetiology
Chronic rheumatic endocarditis
Infective endocarditis
Mitral valve prolaps and myxomatous degeneration
Mitral valve ring dilatation eg dilating cardiomyopathy
Papillary muscle necrosis / ischaemia
Pathophysiology
Chronic mitral regurgitation
Gradual dilatation LALittle increase in pressureLV dilates slowlyLate rise in diastolic and LA pressure
Acute mitral regurgitation
Rapid rise in LA pressure (compliance)
Clinical Features
Symptoms
Dyspnoea (pulmonary venous congestion)
Fatigue (low cardiac output)
Palpitation (AF, increased stroke volume)
Oedema, ascites (right heart failure)
Signs
Atrial fibrillation / flutter
Cardiomegaly – displaced hyperdynamic apex beat
Apical pansystolic murmur ± thrill
Soft S1, apical S3
Signs of pulmonary venous congestion (crepitations, pulmonary oedema, effusions)
Signs of pulmonary hypertension and right heart failure
12.87
InvestigationsECG• Left atrial hypertrophy (if not in AF)• Left ventricular hypertrophy
Chest Radiograph• Enlarged left atrium• Enlarged left ventricle• Pulmonary venous congestion• Pulmonary oedema (if acute)
Echo• Dilated LA, LV• Dynamic LV (unless myocardial dysfunction predominates)• Structural abnormalities of mitral valve (e.g. prolapse)
Doppler• Detects and quantifies regurgitation
Cardiac catheterisation• Dilated LA, dilated LV, mitral regurgitation• Pulmonary hypertension• Coexisting coronary artery disease
Management
Medical management
Mild to moderate MR Diuretics Vasodilators eg ACE Inhibitors Digoxin if AF Anti coagulants if AF A/B prophylaxis for IE
Surgical management
Patient more symptomatic Evidence deteriorating LV function and LV dilatation Mitral valve repair Mitral valve replacement