Arrhythmia refers to any form of abnormal heart rate or rhythm. The normal heart beats 60-100 times per minute when a person is at rest. And it is regular in rhythm. When a person has slow heart rate, i.e. Less than 60 beats per minute; fast heart rate, i.e. more than 100 beats per minute at rest, he/she may have arrhythmia. Sometimes, a person may have normal heart rate but irregular rhythm. He/she may suffer from ectopic heart beats or atrial fibrillation.