A question our team is asked regularly: “Can I use an AED on someone who has a pacemaker / heart condition / diabetes?” The short answer is yes — always. Here’s why, and what to be aware of.
The Key Principle
Defibrillators can be used on any patient suffering Sudden Cardiac Arrest, regardless of their past medical history — cardiac or otherwise. When someone’s heart has stopped, their pre-existing conditions become secondary. The priority is defibrillation and CPR, started as soon as possible.
CPR and defibrillation can be stopped if further information comes to hand indicating it is not warranted — but generally, unless physically impossible, you should continue until qualified help arrives. Qualified help means a paramedic, doctor or nurse.
If in any doubt, call 000 immediately and follow the instructions of the call taker while help is on the way.
Common Questions About Specific Conditions
Pacemakers & Implantable Defibrillators (ICDs)
Use the AED. Avoid placing pads directly over an implanted device if possible — position them at least 2–3cm away. The AED will still work effectively. If the patient’s ICD is already delivering shocks, stand clear and let it do its job first.
Atrial Fibrillation (AF)
AF alone does not cause Sudden Cardiac Arrest, but patients with AF are at higher cardiovascular risk. If a patient with a known AF history goes into cardiac arrest, use the AED without hesitation — the device will analyse the rhythm and only shock if appropriate.
Previous Heart Surgery or Cardiac History
A history of bypass surgery, heart valve repair, heart failure or other cardiac conditions does not change what you do in a cardiac arrest. Start CPR, apply the AED and call 000. The AED will assess the rhythm and advise accordingly.
Diabetes
Diabetes significantly increases the risk of cardiovascular disease and cardiac events. If a diabetic patient collapses and is unresponsive and not breathing normally, treat it as a cardiac arrest — apply the AED and begin CPR while waiting for paramedics.
Stroke
Stroke and cardiac arrest are different emergencies, but a stroke can precede a cardiac arrest. If you are unsure, check for responsiveness and normal breathing. If absent — treat as cardiac arrest. The AED will not shock a patient who does not need it.
Epilepsy
Seizures can be mistaken for cardiac arrest — but the key difference is breathing. A person having a seizure will generally still be breathing. If the patient is unresponsive AND not breathing normally after a seizure, treat as cardiac arrest and apply the AED.
High Blood Pressure & High Cholesterol
Both are significant cardiac risk factors. Patients with hypertension or high cholesterol are at greater risk of sudden cardiac arrest. Having an AED accessible in environments where at-risk individuals work or gather is exactly why workplace AEDs matter.
Medications
You do not need to know what medications a patient is taking in order to use an AED. Some medications affect heart rhythm, which is all the more reason to defibrillate promptly if cardiac arrest occurs. Tell the paramedics what medications the patient takes when they arrive.
Children & Paediatric Patients
Most AEDs can be used on children — many include a paediatric mode or paediatric pads that reduce the energy delivered. If only adult pads are available, use them. An imperfect shock is better than no shock. Ask our team about AED models with built-in paediatric capability.
Other Conditions That Increase Cardiac Risk
The following conditions are associated with increased cardiovascular risk or may be relevant in a cardiac emergency. In all cases, if a person is unresponsive and not breathing normally — treat as cardiac arrest, apply the AED and call 000.
- Cardiomyopathy
- Congestive Cardiac Failure (CCF)
- Ventricular Tachycardia (VT)
- Bradycardia (slow pulse)
- Tachycardia (fast pulse)
- Mitral valve defects
- Obesity
- Chronic Renal Failure (CRF)
- Respiratory history
- Syncope (fainting)
- Trauma
- Post-surgery recovery
The above is a general guide only. If you have any of these conditions, follow your doctor’s advice and recommendations. This information is provided for general awareness purposes only and does not constitute medical advice.
Have a question about AEDs and a specific condition?
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