Monday, 27 September 2010

MRCP revision battle 22.6: Aortic regurgitation

Aortic regurgitation produces a fiendishly difficult to hear early diastolic murmur; I've heard it once and embarked on a most unprofessional victory dance once out of sight of the patient (even more embarrassingly it wasn't even me picking up the murmur, I had been sent to listen to the patient knowing they had the murmur...)

Possibly because its so hard to hear there are a whole troop of eponymous signs that can suggest aortic regurgitation, and MRCP exams love throwing them into questions to excite you:
  • Corrigan's sign: visible carotid pulsation 
  • de Mussets sign: the head bobs with each pulse
  • Duroziez's sign: femoral artery is compressed and auscultated proximally and a diastolic murmur is heard as blood flows backwards during diastole
  • Millers sign: pulsation of uvula
  • Quincke's sign: capillary pulsations in nail be
  • Traube's sign: pistol shot sound over femoral arteries

The less exciting but probably more important points to remember are:
  • the pulse is collapsing (=waterhammer)
  • wide pulse pressure
  • the apex is thrusting

As well as the classic early diastolic murmur best heard down the left sternal edge which is loudest when the patient is leaning forward and in expiration, you need to be aware of the Austin Flint murmur.

Austin Flint murmur only occurs in severe aortic incompetence.  It is a mid diastolic murmur and is probably due to the regurgitant jet interfering with the opening of the mitral valve.

Symptoms of AR are:
  • dyspnoea
  • palpitations
  • heart failure

Causes of AR include:
  • valve inflammation
    • rheumatic fever
    • IE
    • RA
    • SLE
    • appetite supressants
  • aortic root disease
    • hypertension
    • syphillis
    • aortic dissection
    • ankylosing spondylitis
    • psoriasis
  • collagen diseases
    • hurlers syndrome
    • marfans
    • psuedoxanthoma elasticum
One way to remember these causes is SIR AA SHARP  plus collagen.

Management: the aim is to replace the valve before significant LV dysfunction.  Indications for surgery are increasing symptoms, enlarging heart (CXR/echo), worsening ECG (TWI laterally)

Onwards to the brief final battle - the Argyll Robertson Pupil