Quiz: Temporary Pacemaker

2 year old, s/p heart surgery for complex congenital heart disease - having a difficult postoperative course. Upper panel shows a problem with pacemaker. This h been corrected in the lower panel.
1) What is the pacemaker problem in the upper panel? Can you guess the pacemaker mode in the upper panel?
2) What adjustments in the pacemaker will rectify the problem?
3) Lower panel (recorded 2 hrs later): How is the pacemaker functioning now? What are the current settings in the pacemaker i.e. Mode, Rate & AV interval setting?

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