1 yr old boy, s/p Mitral Valve replacement, Postop. AV block. Epicardial DDD pacemaker. HR range is set at 110-180 bpm.
First panel (24-hr trend) shows pacemaker heart rate decreased to ~110 bpm between 6pm & 10pm, when the patient was febrile.
Second panel shows EKG prior to drop in HR.
Third panel shows EKG during the low HR at ~110 bpm (with fever).
Fourth panel shows EKG after return of HR to higher level (after fever).
Fifth panel shows current EKG at the time of review (next day).
1) What are the possible reasons for the pacemaker not to respond appropriately during a time of need (fever)?
2) What further information is needed regarding pacemaker settings to determine the cause of this pacemaker behavior?
3) What change, if any need to be made in the pacemaker settings?