Some cardiac arrests are due to extreme slowing of the heart. About 220,000 people a year die of coronary heart disease without being hospitalized. Most of these are sudden deaths caused by cardiac arrest. Other factors besides heart disease and heart attack can cause cardiac arrest. They include respiratory arrest, electrocution, drowning, choking or trauma.
Cardiac arrest can also occur without any known cause.
Brain death and permanent death start to occur in just four to six minutes after someone experiences cardiac arrest. Cardiac arrest can be reversed in most victims if it's treated within a few minutes with an electric shock to the heart to restore a normal heartbeat. This process is called defibrillation. Few attempts at resuscitation succeed after 10 minutes. No statistics are available for the exact number of cardiac arrests that occur each year.