Agonal respiration is an abnormal pattern of breathing characterized by shallow, slow (3-4 per minute), irregular inspirations followed by irregular pauses. They may also be characterized as gasping, labored breathing, accompanied by strange vocalizations and myoclonus.
Agonal respirations are commonly seen in cases of cardiac arrest, and may persist for several minutes after cessation of heartbeat. The presence of agonal respirations in these cases indicates a more favorable prognosis than in cases of cardiac arrest without agonal respirations.
The cause is due to cerebral ischemia, due to extreme hypoxia or even anoxia. Agonal breathing is an extremely serious medical sign requiring immediate medical attention, as the condition generally progresses to complete apnea and heralds death.