Adrenaline released during intense physical or athletic activity often acts as a trigger for sudden death when these abnormalities are present. Cardiac arrest occurs suddenly and dramatically. It's also sometimes called sudden cardiac arrest or unexpected cardiac arrest . All known heart diseases can lead to cardiac arrest and sudden death. This irregular heart rhythm causes the heart to stop beating suddenly.
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.