When someone suffers cardiac arrest the only definitive treatment is CPR and a shock from a defibrillator, but a defibrillator will only shock what it deems as a “shockable rhythm”.

An Automated External Defibrillator (AED) will first analyse the rhythm of the casualty’s heart and only deliver a shock if the heart is in a certain rhythm, but what is a shockable rhythm?

In recent years, defibrillators have become increasingly available to the public in the UK. These life-saving devices can now regularly be seen in public places such as restaurants, gyms, supermarkets and train stations.

Figures from defibshop’s Cardiac Coverage report show that the number of defibrillators per 10,000 people in the UK has risen from 4.17 in 2021 to 13.71 in 2024. Despite this, many less affluent areas are still below the national average for number of defibrillators, and survival rates for Out of Hospital Cardiac Arrest (OHCA) in these areas are lower as a consequence.

Women who suffer a cardiac arrest in public are much less likely to receive bystander Cardiopulmonary Resuscitation (CPR) than men, research has found.

A study of more than 39,000 cardiac arrests found that men are 28% more likely to receive CPR in public compared to women, but why is this?

Cardiopulmonary resuscitation, or CPR, is a skill that anyone can learn to save someone’s life. CPR and the use of a defibrillator is the only definitive treatment for sudden cardiac arrest.