cardiac arrest

cardiac arrest Cardiac: pertaining to the heart. Arrest: stop. Cardiac arrest: previously equated with death, but since the advent of modern resuscitation methods, an emergency well known to viewers of hospital soaps. When the heart stops, and the circulating blood therefore comes to a standstill, that part of the brain which allows conscious function has only a few minutes to survive. The heart stops beating if the pacemaker-generated rhythm is halted, or if conduction of the electrical impulses is disrupted, sending the muscle of the ventricles — the heart's pumps — into the irregular and useless twitching state of fibrillation. If the instrument and the expertise are available, electric shocks are administered with a defibrillator, which may or may not restore a normal electrical rhythm and hence a regular beat. When this amenity is not at hand, or access to it is delayed, the first aid measure is external cardiac massage, consisting of rhythmic pressure on the chest, at the lower end of the sternum. By squeezing the heart against the spinal column, this can temporarily restore circulation of the blood. Since breathing is likely to have stopped at the same time, or very soon after, the heart beat, attention must be divided between cardiac massage and mouth-to-mouth respiration.

Stuart Judge

See defibrillator; heart; heart attack; resuscitation.