| AED | automatic external defibrillator |
| AHA | American Heart Association |
| ALS | advanced life support |
| arrhythmia | irregular rhythm of the heart muscle |
| cardiac arrest | cessation of the heart muscle |
| CPR | cardiopulmonary resuscitation |
| defibrillation | high-energy pulse of electricity (shock) delivered to the heart muscle to restore normal cardiac activity |
| ECG | electrocardiogram |
| electrocardiogram | curve traced by an electrocardiograph |
| electrocardiograph | instrument used to record electrical currents associated with heart muscle activity |
| fibrillation | rapid twitching movements that replace the normal rhythmic contraction of the heart and may cause a lack of circulation and pulse |
| joule | The amount of energy delivered during defibrillation, related to the intensity of the shock delivered. |
| log | list of ECG samples and time-stamped system events |
| non-shockable rhythm | patient heart rhythms that are not a candidate for defibrillation pulse |
| NSR | normal sinus rhythm |
| RF | radio frequency |
| SCA | sudden cardiac arrest |
| self-test | automatic test performed at system power-up to check readiness of battery, internal circuitry, main processor, and defibrillator |
| shock | defibrillation electrical pulse |
| shockable rhythm | abnormal heart rhythm which is a candidate for defibrillation pulse |
| tachycardia | an abnormally fast heart rate |
| time-stamped event | any change in heart rhythm or any shock delivered by the defibrillator |