Article Text

Download PDFPDF
Coronary pressure measurements: catheter induced errors
  1. M POULLIS, Cardiothoracic Research Fellow, Department of Cardiothoracic Surgery
  1. Hammersmith Hospital, Du Cane Road
  2. East Acton, London W12 0NN, UK
  3. email:

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

Editor,—Coronary pressure derived fractional flow reserve (FFR), as reviewed by Pijls and Bruyne,1 provides an excellent and reproducible technique to estimate the severity of a coronary lesion, and is a significant advance over coronary flow reserve. Three points need to be raised.

First, the arterial pressure measurement should be taken during diastole as most coronary flow is during diastole (not strictly true for the right ventricle). Using mean arterial pressure will induce significant errors.

Second, calculations of FFR without full assessment of the central venous pressure (CVP) may incur significant errors, as the vast majority of patients do not have a CVP of 0. The percentage error incurred when the CVP is not included can be calculated from equation 1. Percentage error in FFR = (1)

Embedded Image

Where Pa = arterial pressure; Pd = distal pressure; and Pcvp = central venous pressure.

This is graphically illustrated in fig 1A, which shows that the percentage error incurred is significant.

Figure 1

(A) Percentage error for various CVPs. Data are shown for FFRs of 0.6, 0.7, and 0.8. A CVP between 5 and 10 mm Hg can incur a …

View Full Text