This came up in Question 19 from the second paper of 2007. The awesomeness of the PA catheter is discussed in greater detail elsewehere.


When is PAWP is higher than the LVEDP?

Pretty much anything that results in an obstruction (or reversal) of forward flow from the pulmonary circulation into the left ventricle will result in a PAWP higher than the LVEDP.

  • Mitral stenosis (gradient across the mitral valve is high, LA pressure is increased)
  • Atrial myxoma (same reason)
  • Mitral regurgitation (large v waves interfere with wedge measurement, and LA pressure is high)
  • Pulmonary fibrosis (obstruction to venous flow)
  • Inappropriate placement (eg. into a high Wests zone)
  • High PEEP
  • High Auto-PEEP

References

An excellent online resource is available, which treats this subject with a massive amount of detail.

This a full-text version of the seminal paper from 1970:

Swan HJ, Ganz W, Forrester J, Marcus H, Diamond G, Chonette D (August 1970). "Catheterization of the heart in man with use of a flow-directed balloon-tipped catheter". N. Engl. J. Med. 283 (9): 447–51.

A manufacturer (Edwards) offers some free information about the PA catheter on their product page.

The PA catheter section from The ICU Book by Paul L Marino (3rd edition, 2007) is a valuable read.