Sometimes I will be sitting at home just chilling and my heart will flutter like it s beating really fast. i can almost feel my aotra pounding. what can this be a sign of?? I know i have a heart murmor is this a side effect?? It kinda worries me... there is no pain involved just an annoying pounding i m scarred it s going to turn into a heart attack. i m a little over weight but i m only 25 ? any advice ?