Are cardiac arrest and sudden death the same thing?

Cardiac arrest and sudden death are generally not the same thing.

Cardiac arrest is when the heart stops beating effectively, preventing blood flow to all parts of the body. In cardiac arrest, the heart's electrical activity is abnormal, causing the heart to fail to contract and pump blood properly. If emergency measures such as cardiopulmonary resuscitation are not performed quickly, cardiac arrest may lead to death. Sudden death is sudden, nonviolent, natural death, usually caused by cardiac causes, such as arrhythmia or structural abnormalities of the heart. Sudden death occurs when the patient suddenly loses consciousness and breathing for a short period of time and quickly enters a state of cardiac arrest requiring immediate cardiopulmonary resuscitation and emergency medical intervention. Cardiac arrest and sudden death are related to some extent, but they are different concepts, so they are not the same.