Why early CPR, accessible AEDs, and bystander confidence are critical in sudden cardiac arrest.
It can happen in an instant. A person collapses – the victim of sudden cardiac arrest (SCA) – and the clock starts ticking in the race to restore a normal rhythm to the heart.
A rescuer armed with an Automated External Defibrillator (AED) and performing CPR is the victim’s best chance for survival until medical personnel arrive.
Indeed, research shows that the probability of survival goes up dramatically when CPR is performed and when an AED is applied before an ambulance arrives.1
“Sudden cardiac arrest (SCA) is one of the leading causes of death in the U.S.,” said Jonathan Bowman, Senior Director of Sales, Acute Care Technologies – ZOLL. “The only effective treatment is a shock from an AED combined with high-quality CPR administered as soon as possible after a victim collapses. This ensures the most favorable outcome.”
An AED will only recommend a shock 50% of the time on the first analysis. A cardiac arrest victim will require high-quality CPR all the time. For the 50% of cases where no shock is advised, high-quality CPR increases the flow of oxygenated blood to the heart, brain, and other vital organs. With CPR, a victim’s chance of survival increases significantly. Even when a shock is advised, a struggling heart needs high-quality CPR to provide it with oxygenated blood to return it to a normal rhythm.
Awareness, education and access
Even with the availability of this technology, barriers to lifesaving action can happen well before emergency responders arrive.
One of the most persistent challenges is fear. “People are afraid to cause more harm, not understanding that you are protected by the Good Samaritan laws, and when someone is not breathing and unresponsive, bystander help is critical to their chances of survival,” Bowman said. Compounding that fear is a widespread misconception that AEDs are only for medical professionals. In reality, Bowman noted, “An AED is designed to be used by anyone for helping someone who is suffering from cardiac arrest.”
Recognition is another hurdle. Many people have never witnessed cardiac arrest and may struggle to identify its signs. Bowman pointed to the importance of broader education efforts, explaining that increased public awareness campaigns and workplace CPR training can help close that gap and empower people to act decisively in emergencies.
Over the past two decades, access to technology has dramatically changed cardiac arrest care. Bowman highlighted the growing availability of AEDs in public spaces and a deeper understanding of CPR effectiveness. “The realization that not all CPR is great, and that monitoring of the quality of CPR can make a huge difference in patient outcomes,” has reshaped resuscitation practices across public, EMS, and hospital settings, Bowman said. This evolution is reflected in the American Heart Association’s ongoing updates to CPR and AED guidelines, including the newly released 2025 recommendations.
Looking ahead, Bowman sees education and accessibility as the next frontier. Continued CPR and AED instruction for students of all ages, mandatory training for coaches and teachers, and better visibility of AED locations are essential. Bowman also pointed to innovation that connects personal technology with AED registries, helping bystanders quickly locate lifesaving devices when seconds matter most.
1 Weisfeldt ML, et al. J Am Coll Cardiol. 2010;55(16):1713–20