Do hope your daughter is lots better now. I appreciate the information you gave, and will follow it up with a pacemaker clinic to get more detail. What you said makes sense.
To ed34: pulse rate increases naturally in response to a high fever to supply more O2 and nutrients to vital body parts, e.g., the heart, brain, lungs, kidneys. That's how our bodies function. Failure to do so puts more strain on these organs, and shock can potentially set in. At 41 deg. C.