People who appear to be absolutely normal are talking to their families, walking around the mall, watching a game when they suddenly have a cardiac arrest. In this case the ideal is to immediately start a resuscitation maneuver and call for medical help, however, this is a difficult situation and time is extremely determinant in the patient's survival.
Many experts claim that within 5 minutes, 50% of individuals who have suffered a cardiac arrest will be dead and thereafter 10% will die with every passing minute. So when all is said and done, in ten minutes everyone will be dead. Thus, we can state that 10 minutes would be a reasonable time to consider resuscitation interruption after complete resuscitation efforts without detectable heart rate.
