As a provider of essential business supplies, we get asked a lot about defibrillators. Are they worth footing the bill, what do they do and so on and so forth…

After a few brief articles in the past giving snapshot guides on these devices, we give you a complete guide to help in deciding whether they’re right for you.


Quickly find your question below:

  1. What is a defibrillator?

  2. Why would someone need a defibrillator?

  3. Difference between heart attack and cardiac arrest

  4. How Long Do Defibrillators Last?

  5. How long do defibrillator batteries last?

  6. How many times can a defibrillator be used?

  7. How many times can a person be defibrillated?

  8. How often do defibrillators work?

  9. Can anyone use a defibrillator?

  10. Do you use a defibrillator when a heart stops?

  11. Does a defibrillator stop a heart?

  12. Can you defibrillate someone with a pacemaker?

  13. Why are defibrillators so expensive?


Defibrillator AED

1. What is a Defibrillator?

A Defibrillator (Also referred to as Defib) is a small electrical device that provides a controlled shock to the heart, in the event of a life-threatening arrhythmia called ventricular fibrillation. The most common type of defibrillator is the AED (This is called an automated external defibrillator).

The AED comes in two forms, either semi-automatic or automatic.

A semi-automatic AED like the defibtech lifeline will detect the rhythm of the heart and tell you when to shock the person in cardiac arrest.

lifeline defibtech

A fully automatic AED like the LIFEPAK CR is designed to be the first person at the scene of a cardiac arrest.  If the patient has a shockable rhythm, the defibrillator automatically delivers a shock without any other user intervention required.

lifepak CR plus

2. Why would someone need a defibrillator?

When a cardiac arrest happens, there is a problem between the electrical impulses between the brains & the heart. This prevents the heart from pumping blood to the rest of the body.

Defibrillators save lives by giving a high energy electric shock to the heart through the chest wall when someone is in cardiac arrest.

The purpose of the electric shock is to restore the normal rhythm – to defibrillate the heart.

There is a big difference between a heart attack and sudden cardiac arrest.

3. Difference between heart attack and cardiac arrest

A heart attack happens when there are issues where the pipes in your body that pump blood to and from the heart get clogged.

Victims may report chest pains days or weeks before the attack happens. The heart will still pump but, at abnormal rates; if you notice any signs of crushing chest pain or shortness of breath contact 999 immediately.

A sudden cardiac arrest is when the heart stops and the person falls unconscious.

4. How Long Do Defibrillators Last?

Defibrillators have replaceable parts.

Rather than the actual models themselves, it’s the batteries and electrode packs that need replacing.

Each Defibrillator model comes with a stand-by life while it isn’t in use. This ranges between 2-5 years while the unit isn’t in direct use. This doesn’t mean the defibrillator needs replacing, this only means that replacement parts are required.

This comes in as either electrode pads or the replacement battery. Batteries usually last a maximum of 5 years shelf life. Pads are considerably less, with an average of 2 years shelf life. Pads should be replaced after each use. Batteries have a maximum number of shocks before replacements are needed.

For more information on defibrillator lifespans, click here.

defibrillator battery

5. How long do defibrillator batteries last?

Nothing lasts forever and with the importance of life-saving devices; you’ll need the right parts to keep them operating smoothly.

Defibrillator batteries have a standby life and a maximum number of shocks, this varies between each model.

For a full itinerary of the defibrillators we sell. Click here.

how long do defibrillator batteries last

6. How many times can a defibrillator be used?

You can use a defibrillator for as long as there are replacement parts available.

The end of life for a defibrillator comes from when the manufacturer can no longer obtain parts (electrodes/pads, batteries).

This is usually many many years after the warranty expires.

The lack of replacement parts makes it more difficult to ensure it is still useful in the event of an emergency.

If you are unsure, give us a call on 0808 278 2741

Here’s a breakdown of some of our best AED units:

Defibrillator Buyers Guide

7. How many times can a person be defibrillated?

First things first. It depends on a few immediate factors:

  • How many shocks can the battery on your AED deliver?
  • How many batteries do you have for your AED?

Every minute without CPR or defibrillation reduces the victim’s survival chances by between 7% and 10%

One study suggested a minimum of 2-3 shocks are most closely related to long-term survival afterwards.

However, physical and underlying conditions vary in people, defibrillator greatly extends survival.

In short; a person can be shocked as many times as necessary, however, with each shock that fails to return the heart to a normal rhythm,  the chances of survival decreases.

8. How often do defibrillators work?

Did you know around 30,000 out-of-hospital cardiac arrests occur every year in the UK?

Without any immediate treatment, 90-95% of cardiac arrest victims will die.

This is where the importance of defibrillators come into place.

Defibrillators can rapidly improve the survival after out-of-hospital cardiac arrests.

For victims who received a shock within three minutes of collapse, the survival rate was 74 %.  That kind of effectiveness speaks volumes to the importance of owning a defibrillator.

9. Can anyone use a defibrillator?

Yes – modern AEDs are all equipped with varying levels of visual and auditory support to aid the user in resuscitating a cardiac arrest victim. Fully automatic defibrillators will even deliver the shock when required!  

They are pretty great devices, allowing anyone to deliver treatment that would previously be only available in a hospital setting.

10. Do you use a defibrillator when a heart stops?

If someone has gone into sudden cardiac arrest, you should first conduct CPR to stimulate the hearts rhythm before using a defibrillator.

Taken from the NHS website, on how to perform CPR:

“1. Place the heel of your hand on the breastbone at the centre of the person’s chest. Place your other hand on top of your first hand and interlock your fingers.

2. Position yourself with your shoulders above your hands.

3. Using your body weight (not just your arms), press straight down by 5–6cm on their chest.”

4. Try to perform chest compressions at 100-120 chest compressions a minute.”

You would then use the AED, follow the instructions carefully and repeat both CPR and the AED before emergency services arrive. Most modern AEDs come with a CPR rhythm counter built in to guide you through this stage.

If the heart can be shocked quickly with an AED, a normal heart rhythm may be restored.

11. Does a defibrillator stop a heart?

The shock from an AED will reset the heart in order to get it beating to a normal rhythm again.

12. Can you defibrillate someone with a pacemaker?

A pacemaker is a small device that is placed in the chest or abdomen to control abnormal heart rhythms. Even with one in, they are still vulnerable to sudden cardiac arrests. For patients with a pacemaker, you will see a scar just over the area on their upper right chest, where you would normally place the electrode pads.

It’s not advisable to place the pads on the pacemaker even though, if they are experiencing sudden cardiac arrest it implies the pacemaker isn’t functioning properly.

The electrode pads pass current from one pad to another, so if you administer a defib shock to a pacemaker, place it a few inches below the recommended placement. Remember, the current needs to pass-through the heart between the two pads.

13. Why are defibrillators so expensive?

You pay for a piece of mind. These aren’t called life-saving devices without being able to live up the name.

When you factor in the price you need to think about (not limited to)

  • These aren’t double AA batteries. A lot of expense and design goes into making them long-lasting, low maintenance and protection against all potential complications.
  • The high voltage components needed to power and conduct the intense voltage shocks do not come cheap.
  • Mass production with solid testing and assurance the devices are fully regulated.

You’re carrying a device which if it was faulty and unregulated could very well kill you. That’s why the utmost care is taken to make sure nothing goes wrong when using them in the event of an emergency

See our complete selection of life-saving devices here at Direct365 supplies

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