“Is heart tachycardia after COVID vaccine normal?”

It is not normal, but it can happen after the vaccine.  We are finding that a lot of side effects can happen after the vaccine.  Some of the more common side effects are fever, fatigue, and a rash.  But, tachycardia is not a common side effect.  If the tachycardia persists, you should see your doctor or go to the emergency room if your breathing or endurance is also affected.

Only if you got some fever from the vaccine??