Sometimes problems with the heart's electrical signals lead to a fast heart rhythm. Too many signals may make the heart beat very fast (tachycardia). Or signals may be sent so rapidly and irregularly that the heart muscle sometimes quivers and doesn't beat at all (fibrillation).
An arrhythmia is a change from the normal speed or pattern of your heartbeat. Learn about the symptoms and causes and how to care for yourself when you have one.
Any abnormal change in the speed or pattern of the heartbeat is called an arrhythmia. An arrhythmia that causes the heart to beat slower than normal is called bradycardia.
