A change in the normal pattern of the heartbeat is called

A) angina pectoris.
B) distress.
C) heart attack.
D) arrhythmia.

An arrhythmia is a condition in which the normal rhythm of the heartbeat is disrupted. This can lead to a heartbeat that is too slow, too fast, or irregular. Angina pectoris and heart attack are both conditions that involve a blockage or narrowing of the blood vessels that supply the heart, while distress is a general term for emotional or physical strain.