Friday 19 November 2010

MRCP revision battle 54.4: Cardiac axis

The normal cardiac axis is -30 to +90 degrees.

More negative = left axis deviation
More positive = right axis deviation.


Causes of left axis deviation:
  • LBBB
  • LVH
  • ASD
  • cardiomyopathies
  • aortic stenosis
  • can be normal in:
    • ascites
    • pregnancy
    • obesity

Causes of right axis deviation:
  • RBBB
  • RVH --> lung disease
  • PE
  • can be normal in:
    • infancy
    • thin people


Next: haemolysis