A year a go i had an echo ultrasound n a 24 holter monitor everything was fine i still have palpitations n missed heart beats specially when stresses. no other simptoms. should i worry?

Lab results: Your tests suggest you don't need to worry but that reassurance is more valuable if it comes from a physician who knows more about you.

Probably not: palpitates can be a sign of serious things like a-fib etc. But most of the time its just unerving . the echo is reassuring as structurally normal hearts are unlikely to have life threatening issues. The holter is fine but unless you have any symptoms during the 24 hrs it may miss things. I suggest a 30 day event recorder to cast a wider net, and do a stress echo to see if exercise shows the cause.