What is bradycardia (slow heart rate)?

Bradycardia refers to a slow heartbeat that is less than 60 beats per minute. If you are physically fit, you may have a slow heart rate at rest, and this is perfectly normal for you. But a heart rate lower than 60 beats a minute at rest may indicate a more serious problem for someone who is not physically fit.

Sometimes bradycardia means that the heart is not pumping enough blood through the body. Types of bradycardia include sick sinus syndrome and conduction blocks. With sick sinus syndrome, the sinus node, or the heart's natural pacemaker, isn't sending the electrical impulses properly. Sick sinus syndrome may be the result of scar tissue near the sinus node, which can result in stopping or disrupting the travel of the impulses. With a conduction block, the electrical impulses between the upper and lower sections of the heart may slow down or stop. Sometimes there are no symptoms when the impulse is blocked, yet other times you will experience bradycardia (slow heartbeat) or even skipped heartbeats.