A slower-than-normal heart rate is called A slower-than-normal heart rate is called tachycardia. premature contractions. bradycardia. fibrillation. None of the answers is correct.

Answer: it is called Bradycardia.

Explanation:

Bradycardia is a slower that normal heart rate. The heart rate of adult human usually beats between 60 to 100 per minutes. A testing heart rate less than 60 beats per minutes is called Bradycardia with the exception of Adult in deep sleep. It could be a serious problem if the heart could not pump oxygen rich blood to the body. It is caused by damaged of heart tissues from heart disease or due to aging. Heart disorder from birth or infection of heart tissue