Asphyxial arrest is cardiac arrest caused by asphyxiation. In contrast to a myocardial infarction, which is a heart attack caused by a lack of blood supply to the heart, an asphyxial arrest is caused by a lack of oxygen in the blood.
Asphyxia is respiratory failure, which causes an extremely deficient supply of oxygen to the body. It occurs in drowning victims, choking victims and in other circumstances that obstruct the airway or otherwise prevent the intake of oxygen.
Asphyxiation prevents oxygen from reaching vital organs, including the heart, resulting in a depletion of oxygen in the blood. During asphyxiation, the heart continues to pump blood.
The circulatory system normally delivers carbon dioxide to the lungs where it is exhaled and the blood is reoxygenated. During asphyxia, this process ceases. Carbon dioxide accumulates in the lungs while the oxygen supply in the lungs is depleted, resulting in cardiac arrest.
The heart will stop beating when the oxygen supply is depleted and enough carbon dioxide has accumulated in the lungs. This is called asphyxial arrest.