Cardiac arrest is a life-threatening condition where the heart stops pumping blood, often caused by heart disease and electrical system malfunctions. Immediate intervention, such as CPR and defibrillation, is crucial for survival, as brain damage or death can occur within minutes. Various factors, including previous heart attacks, cardiomyopathy, electrical abnormalities, and drug use, can contribute to cardiac arrest, and treatment options may include advanced therapies like implantable cardioverter-defibrillators.