What is a defibrillator?

The automated external defibrillator or AED, helps saves lives in case of sudden cardiac arrest (SCA). An AED is a medical device that is connected to an SCA patient via disposable electrode pads. It analyses a person’s heart rhythm for a potentially fatal irregular heartbeat. The AED automatically recognizes a heartbeat that requires a shock. The AED uses text and voice prompts to communicate rescue steps, and when the electrical shock will be delivered. The shock in turn, can restore the heart back to a normal rhythm.

AEDs are very accurate and very easy to use. Anyone can learn to operate an AED safely.


Rescuers give shocks by pushing a button.

Fully Automatic

The device delivers the shock during the rescue when necessary without human intervention.


How does the AED work?

When someone is in sudden cardiac arrest (SCA) every minute counts. The adhesive pads (electrodes) are attached to the chest of the person who is having the SCA. The electrodes send information about the person’s heart rhythm to the AED. The AED analyzes the heart rhythm to find out whether an electric shock is needed. If the patient is in a shockable rhythm the AED will give an automatic shock (if the AED is fully automatic) if the AED is a semi-automatic the AED will give voice instructions to press red flashing button to administer a shock. When the analysis and shock instructions have been given CPR must then commence when the AED instructs to do so. The AED will continue to analyse the heart rhythm until the pads are removed from the chest.


Where should AEDs be?

Anywhere there are people there is a potential risk for a SCA.

First-response vehicles

Public areas

Shopping centres

Sports arenas

Schools/high schools/colleges/universities



GP surgeries

Touristic places

Office complexes (offices, shops, factories, warehouses, construction sites…)…..Everywhere!


How to choose an AED?

Because all the AEDs are not the same and because early defibrillation is very important, you need to choose well your defibrillator. Here are some factors to take into account before buying an AED.

  • Choose a specialist of medical devices.
  • The AED must be always ready and easy to use.
  • According to the 2015 ERC guidelines, “it is appropriate to consider escalating the shock energy if feasible, after a failed shock and for patients where re-fibrillation occurs
  • Pre-connected electrodes (when you turn the AED on, they are already connected to the device) and preferably non-polarised (the electrodes can be placed in either position).
  • A defibrillator is more efficient if it can deliver shocks by taking into account the corpulence and the morphology of the patient for a maximum efficiency.
  • CPR is an important link in the chain of survival. A CPR aid helps provide the rescuer with guidance during the CPR and feedback. The 2015 ERC and AHA guidelines recommend that CPR feedback should ensure effective compressions according to the rate, depth and recoil.
  • FDA agreement (Food and Drug Administration). In the US, the FDA is the authority in charge of controlling the AED market and the manufacturers. To be FDA approved involves alot of testing and anaylsys. Having the FDA agreement is a token of the safety and quality of the product.
  • The battery must be powerful and long lasting. The AED uses the energy of the batteries to do automatic self-tests and to ensure having enough energy necessary for a rescue. If you want a high-quality AED, you should buy an AED using medical batteries. Medical grade batteries can last for years even when used to do self-tests every day.
  • A good AED must be sensitive to the detection of the asystole threshold. The more sensitivity of the detection, the better the ability of the AED to detect the lower cardiac fibrillation and to decide to deliver a shock.
  • Check the costs of the consumables (batteries and electrodes) and if a service or maintenance contract is required or not.
  • Check the AED and consumables (battery and electrodes) warranty and find out what it covers.
  • Make sure the AED can work easily in your environment (humidity, temperature, noise)
  • Check you can upgrade the latest AED updates for free, to meet the ERC and AHA guidelines.
  • Is the download software data, free of charge?