A cardiac arrest occurs when your heart suddenly stops beating. The heart functions through electrical pulses, and when those pulses are interrupted it can cause an irregular heartbeat or cardiac arrest. The cause of cardiac arrest is an electrical problem. It does not have anything to do with your arteries’ functions. cardiac arrest occurs when your heart suddenly stops beating. The heart functions through electrical pulses, and when those pulses are interrupted it can cause an irregular heartbeat or cardiac arrest. The cause of cardiac arrest is an electrical problem. It does not have anything to do with your arteries’ functions.