Cardiac arrest is a sudden and unexpected loss of heart function, breathing, and consciousness, often due to arrhythmias and leading to death if not promptly treated. Incidence rates vary significantly across populations, with a study in India showing an annual incidence of 53 per 100,000 residents, and survival rates depend inversely on incidence. Management includes immediate CPR, defibrillation, medications, lifestyle changes, and surgical procedures such as catheter ablation and pacemaker implantation.