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