Bradycardia is a slower than normal heart rate.

The adult heart (at rest) beats at about 60 to 80 beats per minute. Fifty-five to 60 beats per minute would be considered bradycardia for an adult. Infants, however, have a much higher at rest heart rate (110 to l30 beats per minute), thus; bradycardia in infants would be a rate below 100 beats per minute.

Slower than average heart rates are normal in people who are physically fit and people who are sleeping. Many athletes who train regularly have...