Out of the blue my heart began racing the two nights ago. My resting hr is usually somewhere in the 50’s (which I think is too low as I’m certainly not fit) but it rose from the mid 69s up to about 100bpm before it slowly dropped again but remained in the high 60s all night.
Since then it hasn’t happened again but it is a little bit elevated and I’m feeling anxious at rest.
Why could this be?
I should say I’m experiencing a return of symptoms recently but my heart racing was never an issue before.