Introduction

Mitral regurgitation can be cause be either a primary valve disorder, or can be secondary to left ventricular dysfunction.

In the developed world, most cases are due to degenerative mitral valve disease or coronary artery disease. In the developing world and amongst indigenous populations in developed countries, rheumatic heart disease remains a common cause.

Mitral regurgitation eventually overloads the left ventricle, leading to heart failure, but there is often a long asymptomatic period as the condition progresses before it reaches this point. Left ventricular size and function are often used to assess the extent of mitral regurgitation disease.

Causes

Rule of two’s

Heart

  • LV dilatation
  • Annular Calcification

Infective

Connective Tissue Disorders

Appetite Suppressants

Signs

  • Pansystolic murmur best heard in the mitral area, radiating to the axilla.
  • Heave
  • Displaced Apex Beat
  • Possible signs of:
    • Heart failure / pulmonary hypertension: crackles at the lung bases, pink frothy sputum, oedema etc
    • AF – irregularly irregular pulse
 
Hang on a minute! – the blood in mitral regurgitation is flowing away from the axilla – why does the sound radiate to the axilla?
  • Well, the sound comes from the valve itself, and is not related to the direction of flow of blood. Due to the location of the mitral valve, any sound it produces (whether from regurg or stenosis) will radiate to the axilla.
 

Symptoms

Signs of any valve defect

  • Fatigue
  • Dyspnoea
 
 

Investigations

  • ECG – P Mitrale – ‘bifid’ (two-peaks) P waves due to atrial hypertrophy
  • Trans-Oesophageal Echocardiogram – TOE – used to asses the level of valve damage, to check if suitable for valve repair / replacement
  • Doppler-Echo – assesses the site and size of the regurgitant jet
  • Cardiac catheterisation – may be used to confirm the diagnosis, and to assess the level of underlying CAD (coronary artery disease)
 
 

Management

  • Conservative – lifestyle advice (e.g. avoidance of RFs for underlying cause)
  • Medical – control the signs and symptoms; e.g. diuretics if heart failure is a component, treat AF
  • Surgical – patients may require valve replacement or repair.
    • Patients should be placed on antibiotics to prevent bacterial endocarditis

Valve replacement

  • Prosthetic – last about 10 years, after which time, may require another replacement. No need for long term anticoagulant therapy.
  • Metal – last a life time, but require anticoagulant therapy for life. Also noisy (often make a loud ‘click’ sound). There are three types of metal valve
    • Tilting disc
    • Double tilting disc
    • Ball in a cage

References

  • Mitral Regurgitation - UpToDate
  • Murtagh’s General Practice. 6th Ed. (2015) John Murtagh, Jill Rosenblatt
  • Oxford Handbook of General Practice. 3rd Ed. (2010) Simon, C., Everitt, H., van Drop, F.

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