Your question: What is agonal breathing?
My humble answer: Agonal breathing is inadequate breaths or gasps. According to the Medical Priority Dispatch System agonal breathing is determined by watching a person breathe. "If the time betwen breaths is 10 seconds or more, this should immediately be considered INEFFECTIVE BREATHING that is likely a fading, AGONAL (dying) respiratory pattern." Agonal breathing is a sign of a very recent cardiac arrest. If you observe agonal breathing you should consider the patient in complete respiratory arrest and treat the patient by providing positive pressure breaths with an AMBU bag.