Hello, please could someone explain why an 89yr old lady with a pacemaker was unable to raise her pulse rate above the paced 70 bpm to meet the metabolic requirements of a 39.3 - 40deg. fever. She has a double chamber pacemaker inserted for total heart block. Also, what were the metabolic implications for her? Respiratory acidosis, metabolic acidosis? I am doing research but not always understanding what I'm reading. Would be grateful for any help.