Arrhythmias are due to a disturbance of the electrical impulses which regulate the heart. The heart may beat too slowly (bradycardia), too quickly (tachycardia) or in an irregular way. The normal heart rate is between 60-100 beats per minute for adults.
This is a companion discussion topic for the original article at https://patient.info/doctor/cardiovascular-disease/anti-arrhythmic-drugs