Basic Operating Procedures
ACIST RXi System User’s Guide |
39
901700-001,01 2019-09 English
Deliver the Navvus® MicroCatheter, Equalize Signals, and Enter Venous Pressure
7. Review and adjust the venous pressure value if necessary. (The default
value for the venous pressure on the ACIST RXi System is 0 mmHg.)
All displayed calculations of resting Pd/Pa and FFR include a correction
for the current Pv setting as shown in the following equation:
FFR =
Pd - Pv
Pa - Pv
The variables in this equation represent the following values:
•
FFR
is the fractional flow reserve.
•
Pd
is the mean arterial pressure distal to the stenosis as measured by
the Navvus MicroCatheter.
•
Pv
is the systemic venous pressure.
•
Pa
is the mean aortic pressure at the ostium.
High venous pressure (above 8 mmHg) will have a significant impact on
FFR and resting Pd/Pa values. A high Pv value results in lower FFR and
resting Pd/Pa values.
To change the venous pressure value, perform these steps:
•
Press the
Pv
button on the main screen.
•
Enter the Pv value using the plus (+) or minus (-) buttons.
The Pv value entered is displayed in the main screen.
Note
The Pv value will revert to the default value after the procedure for the current patient is
completed. See page 73 for detailed instructions for changing the default Pv value.