What is the Maximum Heart Rate of a Kardia EKG? Updated March 26, 2021 21:07 The maximum heart rate calculated from a Kardia EKG is 220 bpm. Related articles Can Kardia Mobile or Kardia Band detect Arrhythmias other than AFIb? How do I take a 6-Lead recording using my KardiaMobile 6L? Are locally stored EKG’s taking up space on my device? What is the Paper Speed of the Kardia EKGs recorded with Kardia devices? Why is the ECG upside-down? How do I adjust ECGs that have been recorded upside-down?