Mitral Valve Disease Prof JD Marx UFS January 2006

Anatomy

Mitral Stenosis Aetiology Almost always rheumatic Heavy calcification in elderly Congenital MS in infants

Pathophysiology Mitral valve orifice diminished by progressive fibrosis calcification valve leaflets fusion cusps subvalvular apparatus

Bloodflow LA to LV restricted 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

Symptoms 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)

Signs Atrial fibrillation Mitral facies Auscultation Loud first heart sound. Opening snap Mid-diastolic murmur Signs of raised pulmonary capillary pressure Crepitations, pulmonary oedema, effusions Signs of pulmonary hypertension RV heave, loud P2

Investigations ECG Chest Radiograph Echo Doppler 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

Management 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

Surgical procedures Mechanical disease Consider - patient symptomatic - pulmonary hypertension - atrial fibrillation - MVA 1 cm² or less Mitral balloon valvuloplasty Open mitral replacement

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 LA Little increase in pressure LV dilates slowly Late 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

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Investigations ECG Chest Radiograph Echo Doppler 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 Surgical 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