My heart isn't great, i had some problems with it sometimes in the past few years. Mine feels as if it's hitting my chest kinda, when i lay down/ it just feels weird... Is that what it feels like? If it's doing it now, go to the hospital NOW and tell them it's urgent, because without it happening when a medical person is there, they won't have a clue what's wrong unless you've got blatant symptoms, if you can time it right when they do an ECG (sticky pad things, hurts when they pull them off) and see what's wrong. Have you done a lot of exercise lately? And or haven't slept much? Or had loads of stimulants like red bull, chocolate, coffee, coke/carbonated drinks? Things like that can set mine off (i only have chocolate or fizzy drinks very rarely, don't eat crisps anymore and no redbull/drinks like that have passed my lips for a good few years, never eat macdonalds, and rarley have burgers, once a year probably)) Just get it checked.