Mitral regurgitation

Causes:

chronic

– rheumatic heart disease

– degenerative disease

– mitral valve prolapse

– papillary muscle dysfunction secondary to left ventricular failure or chronic ischaemia

– cardiomyopathy

– connective tissue disease – Marfan’s / rheumatoid arthritis / ankylosing spondylitis

– congenital

 

acute

– infective endocarditis

– papillary muscle rupture post-AMI

– mitral valve replacement

– trauma

 

Symptoms:

acute – acute pulmonary oedema, cardiogenic shock

chronic – dyspnoea, fatigue

 

Signs:

acute

tachypnoea

systolic apical thrill

loud apical systolic murmur

chronic

atrial fibrillation

displaced apex beat +/- pansystolic thrill at apex +/- parasternal impulse (due to very large left atrium)

soft S1

S3

pansystolic murmur loudest at apex, radiating to axilla

signs and symptoms due to the enlarged left atrium compressing the adjacent structures – dysphonia (recurrent laryngeal nerve); dysphagia (oesophagus)

 

ECG findings:

P mitrale; AF; right axis deviation

 

Severe mitral regurgitation:

small volume pulse

early diastolic rumble

signs of pulmonary hypertension

signs of left ventricular failure

echo – enlarged left ventricle; regurgitant fraction > 60% stroke volume

Management precautions:

– AVOID bradycardia (ideal HR 80 – 100/min)

– AVOID excessive volume load

– in case of acute pulmonary oedema in a patient with mitral regurgitation consider using GTN or nitroprusside infusion to increase forward flow; however, some patients may become severely hypotensive – add dobutamine