I'm a Cardiac Physiologist, palpitations are extra active from the "electrics" within your heart muscle.
If they are in frequent but you are aware see if they occur with certain foods and drink. Caffeine /Chocolate /wine can bring them on, plus stress, Covid could be the instigator some Viruses can cause this, depends how your body reacts.
Some people report they feel their Heart stop after a Palp, but it's just the Heart resyncing so it doesn't get confused.
If A&E let you home they didn't find any abnormal rhythm. Bloods would have rules out any major Coronary Heart issues.
If they continues to drive you potty, speak again to your GP, they might give you a short dose of Beta blockers and possibly a Home Monitor to record you long term ECG.
You should be fine, but don't worry. Every one gets Palpitations (Ectopics) you just are not aware most of the time,
Take care.
