MITRAL REGURGITATION

AETIOLOGY

1. Mitral valve prolapse

2. Dilatation of the mitral valve ring (e.g. rheumatic fever, myocarditis, cardiomyopathy)

3. Damage to valve cusps and chordae (rheumatic heart disease - is coexisting mitral stenosis and/or aortic valve disease; endocarditis)

4. Damage to papillary muscle

5. Myocardial infaction

SYMPTOMS of REGURGITATION:

• chronic - produces volume overload of the left atrium and ventricle - dilatation

• exertional dyspnoea, nocturnal dyspnoea, palpitations

• symptoms of pulmonary oedema

• symptoms of diminished cardiac output (tiredness, fatique)

• symptoms of right ventricular failure

• acute - rapid rise of left atrial and pulmonary venous pressure, rapid decrease of stroke volume - pulmonary oedema and symptoms of reduced cardiac output

SIGNS of MITRAL REGURGITATION

• atrial fibrillation/flutter

• cardiomegaly

• apical holosystolic murmur (it is heard best in the apex, radiates into axilla, may be accompanied by a thrill)

• quiet first heart sound (abnormal valve closure), loud third sound sometimes accompanied by short mid-diastolic murmur (the increased forward flow through the mitral valve)

• apex beat displaced to the left (result of dilatation of the left ventricle)

• signs of rised pulmonary capillary pressure (crepitations, pulmonary oedema, effisions)

• signs of pulmonary hypertension

In practice, the usual problem lies in deciding the extent to which cardiac failure is due to mitral regurgitation and extent to which it reflects impaired left ventricular function.

INVESTIGATION IN MITRAL REGURGITATION

1. ECG - left atrial hypertrophy (AF), left ventricular hypertrophy

2. CXR - enlarged left atrium, enlarged left ventricle, signs of pulmonary venous hypertension, signs of pulmonary oedema

3. Echocardiography - dilated LA, LV, dynamic LV (unless LVF predominates), regurgitation detectable on Doppler

4. Cardiac caheterisation - dilated LA, LV, mitral regurgitation, pulmonary hypertension (chronic MR)

Category: Cardiology Notes