And my ECG and Echo were normal. What could be the reason? l had anxiety few years back.

getting tired

Everyone gets it.

Its natural, when you are perfectly relaxed and hold your breath.

When my heart is beating particuarly fast l can see my beat in my chest.

You might also be having muscle spasms or twitches if you feel a pulsing sensation in your legs or deltoids.

l quite enjoy that sensation :D

maybe you're having a heart burn..

it is called adrenaline..but it might help if you got off the drugs? XP

YOUR FEELING THE EFFECTS OF SOUND TRAVELING THROUGH vibrations. Sound and vibration travels faster through water than air.

heart papls can occur due to many things , stress caffeine, anxiety, In my case l had a short circuit, not life threatening but a seriously scary thing to experience out of the no where. try not drinking any caffeine or alcohol, for a while and see if it stops. also most people experience this feeling while laying down after standing or moving all day, the shift in your body is position can cause blood to flow more rapidly towards your heart making it palpitate

ohhhhh your fine it happends to all of us all the time sometimes we do not notice cause we do not worry about it.
so you fine it happends to me

well anxiety never leaves u even after treatment so there is a possibility its anxiety

Still it could be anxiety.