I wear an Apple Watch and run the Seizure heart rate monitor and instant EKG. My heart rate jumps over 200bpm without activity. It can happen while I’m sleeping, sitting or moving. I wear an Apple Watch and run the Kardia heart rate monitor and instant EKG. But after a month it working stop so I am going with this link https://www.applemacsupportnumbers.com/iphone-technical-support/ to solve it. The reasons for sharing is if anyone has any issue with Apple gadgets to use this to solve it because life is more important than money.