BIOTRONIK Evia HF - Measuring Retrograde Conduction; Requirements for Measurement

Chapter 10 Follow-up Procedures
Evia HF / HF-T Technical Manual
PAGE 104
Figure 65: Retrograde Conduction Test with a Positive Result
Retrograde conduction from the ventricle to the atrium can be conrmed when a 1:1 relationship with
a constant V-A interval is present. The VA interval is the time between the ventricular paced event and
the rst subsequent atrial sense.
The programmer displays the measured results as the maximum, minimum, and mean retrograde
conduction times. If the measured maximum, minimum and mean values are within 25 ms of each
other, retrograde conduction is suspected. One may repeat the test to conrm the results.
While the test is being performed, the measured V-A times are displayed on the programmer screen.
10.5.1 Measuring Retrograde Conduction
The Retrograde Conduction measurement is initiated from the Retrograde conduction tab. During
the test, the pacemaker operates in VDI mode at a programmable rate that must exceed the heart’s
intrinsic rate. The V-A interval is measured using the event markers on the IEGM (V pace to A sense).
The measurement begins after the START tab is pressed. The rst ve cycles are not used in the
measurement.
10.5.2 Requirements for Measurement
• The programming head must have telemetry contact with the implant for the entire measurement
duration. If telemetry contact is interrupted, the measuring process will be aborted. (This is true for
all tests.) The values measured up to this point remain displayed.
• Retrograde conduction can only be measured if ventricular pacing and atrial sensing
are present.
• The ventricular pacing rate for the retrograde conduction test MUST be greater than the intrinsic
atrial rate.
NOTE:
Retrograde conduction may not be present at all rates. If retrograde conduction is suspected, perform
the test at different rates.