Question: what is cardiac arrest really?

Heart stoppage: A cardiac arrest literally translates to heart stop. Ultimately this means that heart's main function to pump blood to vital organs has abruptly halted. The heart may fail to pump when the electrical impulse which signals the heart muscle when to pump becomes too fast, too slow, or even if normal in the event that the muscle is unresponsive to the current.

Stopped heart: Cardiac arrest occurs when the heart stops pumping blood forward . The stoppage is usually due to to a change in the heart's electrical rhythm that prevents the muscle cells from squeezing in an organized fashion. Cardiac arrest can also occur with a normal heart rhythm, if the heart is too weak to pump blood or too empty to have blood to pump. In any case, immediate resuscitation is needed.