My heart won t stop fluttering. It started a few months ago and would go away after a few days, but right now it s at the point where it flutters almost every other second. I have no other symptoms, just a fluttering or tremor-like feeling that lasts one second each. I did have coffee three hours ago and worked out afterward. I drink and smoke on a regular basis and was wondering if maybe it s part of the hangover?