Brief Answer:
Needs management

Detailed Answer:
Thank you for asking.
Lying down is resting position and does not demand much blood so heart beats at a slower pace.when standing up suddenly the best goes up.it is a normal phenomenon.epinephrine surges cause that. But derangement that much is worth assessment.
Do you stand up suddenly from laying down ? If so please avoid such acts in future.sit down from laying for a while.rub your eyes with your palms that induces occulocardiac reflex and help dampen the accelerating pace of the heart.
And then wait for a while and then slowly stand up with a support.
See if it helps.if it still persists then it is not normal and reflex tachycardia irrespective of the etiology it is.
Standing up reduces blood pressure is some people called ortho static hypotension and that reduced pressure reduces flow to the heart and and heart responds by increasing the pace
Needs a little assessment and a work up to connect all the dots. That would require you a visit to nearby cardiologist and let them decide what it is. Hoping for the best and most likely a natural entity is suspected here requiring just modification we talked.
I hope it helps. Take good care of yourself and don't forget to close the discussion please.
May the odds be ever in your favour.
Regards XXXXXXX

---