Bradycardia means a slowed heart rate. In premature babies, bradycardia is a heart rate of less than 80 beats per minute.

In premature babies, apnea and bradycardia often occur together, along with low blood oxygen levels. First, apnea occurs and the baby will stop breathing. Because the baby isn’t breathing, blood oxygen levels will fall. The heart slows down in response to the low blood oxygen levels.