Arrhythmia

An arrhythmia is an uneven heartbeat. It means your heart is out of its usual rhythm. It may feel like your heart skipped a beat, added a beat, or is "fluttering." It might feel like it’s beating too fast or too slow. Or you might not notice anything. Arrhythmias can be an emergency, or they could be harmless. If you feel something unusual happening with your heartbeat, get medical help right away so doctors can find out why it's happening and what you need to do about it.