What causes random low heart rate readings on Apple Watch Ultra 2?

Just wanted to let anyone know who sees a random low HR on their Apple Watch. Like today I had a random 46. If you go into health and hr and show all data, scroll till you fine the low hr, click on it and if it says ECG, it was a glitch. The watch tried to run an ecg in the background. So it means you either moved it or didn’t get a proper reading. You will see the rest of the HRs on the list will be listed as “work out” but the random low you see will generally say “ECG”

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