This document provides information on how to use an automated external defibrillator (AED) for cardiac emergencies. It discusses that AEDs can correct abnormal heart rhythms through defibrillation shocks. It emphasizes the importance of immediately using an AED on unresponsive, non-breathing, and pulseless patients and continuing CPR until the AED is ready to analyze the heart rhythm. The document outlines the steps to take when using an AED, including turning it on, attaching pads to the patient's chest, analyzing the rhythm, delivering shocks if advised, and continuing CPR between analyses. It notes some variations depending on the AED model and patient age.