Why do i get palpitations when i lay down. usually after 20mins then they really start. when i'm nearly asleep 30yrs otherwise healthy. not anxiety?

Reflux or notice : Maybe reflux as pain or burning not necessarily noted with reflux and cough and or palpitations maybe only notable symptom. Everyone has palpations and some people are more in tune with these changes a fee test would be needed to assure this is normal heart beat changes or if there is something abnormal going on even at the young age of thirty. Hope all is well.