Automated External Defibrillators (AEDs) save lives threatened by sudden cardiac arrest. However even when the lifesaving devices are widely deployed, they are not always available when needed, according to a new study reported at the American Heart Association Scientific Sessions. To address the issue, the Sudden Cardiac Arrest Foundation calls for 24/7 access to the lifesaving devices.
Sudden cardiac arrest (SCA) is the third leading cause of death in the United States.  In the U.S. alone, approximately 326,200 people of all ages experience EMS-assessed out-of-hospital non-traumatic SCA each year and nine out of 10 victims die.  In fact, the number of people who die each year from SCA is roughly equivalent to the number who die from Alzheimers disease, assault with firearms, breast cancer, cervical cancer, colorectal cancer, diabetes, HIV, house fires, motor vehicle accidents, prostate cancer and suicides combined. 
While these statistics paint a dismal picture, it is encouraging to know that SCA can be treated successfully through early intervention. Over the past decade, great strides have been made to reduce SCA mortality through more widespread CPR-AED training and AED deployment. In addition, thanks to proactive action taken by state legislatures, liability concerns for Good Samaritans responding to SCA have largely disappeared.
An AED is a portable device used to treat cardiac arrest. The smart, user-friendly device automatically analyzes heart rhythms and advises the operator to deliver a shock if the heart is in a fatal rhythm. Shocks from the AED disrupt deadly heart rhythms, allowing a normal heartbeat to resume naturally. (Think of rebooting a computer).
An extensive body of research has proven the effectiveness of AEDs, which are designed for use by the lay public. Non-medical laypersons can use AEDs safely and effectively with minimal training. To be most effective, however, AEDs must be used quickly--ideally within a few minutes after the victim becomes unconscious and unresponsive, and stops breathing normally.
Use of AEDs by bystanders is already making a significant difference. While the average rate of survival from cardiac arrest occurring outside hospitals is about 10 percent, the survival rate increases to nearly 40 percent when bystanders give CPR and use AEDs before EMS arrives at the scene.  Some communities with exceptionally strong CPR-AED programs have reported survival rates as high as 70 percent. The Sudden Cardiac Arrest Foundation's growing survivor network is a testament to the success of strong community CPR-AED programs.
The undeniable success of AEDs has led to an increase in publicly available defibrillators. It is a huge step in the right direction that AEDs are being deployed more widely in communities across the U.S.
New research, however, highlights the fact that there is still much more work to be done. Christopher Sun and Timothy Chan, researchers at the University of Toronto, recently completed a study that examined 451 cases of sudden cardiac arrest. The incidents all occurred within 100 meters of an AED. One-quarter of the time, AEDs were inaccessible--behind locked doors. Nearly two-thirds of the cases examined occurred during weekends or at night, thus limiting access to AEDs placed in nearby office buildings, schools, and recreational facilities, which were closed and locked during these off-hours. 
This study highlights a serious flaw in current thinking about AED deployment and ignores a basic premise that lifesaving equipment needs to be available 24/7. Also complicating efforts is the fact that most AEDs are not designed to be left out in the elements. They have sensitive equipment, such as batteries, circuit boards, and gel pads, which may be compromised by fluctuations in temperature and moisture. As such, AEDs stored outdoors need to be in climate-controlled cabinets that are readily accessible.
Innovative strategies for AED deployment are being explored, including deliveries by Uber, Lyft, and cardiac drones. In addition, installation at ATM machines and integration into existing vending machines--which are climate-controlled--is a possibility. (In Japan, AEDs have been installed in vending machines since 2007.) Further, AED apps are being used to alert volunteers to respond when cardiac emergencies occur.
As we continue to build our crowd-sourced and mobile-enhanced way of life in the United States, we must develop new and innovative ways to get lifesaving equipment to emergencies quickly and safely. We must work to ensure that lifesaving AEDs are readily available, 24/7, whenever sudden unexpected cardiac arrest occurs. AEDs save lives, but AEDs in hiding are rendered useless.
Contributing author: Andrew Roszak, Esq., JD, MPA, Sudden Cardiac Arrest Foundation Advisor
 IOM (Institute of Medicine). 2015. Strategies to improve cardiac arrest survival: A time to act. Washington, DC: The National Academies Press.
 Heart Disease and Stroke Statistics -- 2015 Update: A Report From the American Heart Association. Circulation. 2015; 131: e29-e322. Published online before print December 17, 2014, doi: 10.1161/CIR.0000000000000152.
 Sudden Cardiac Arrest Foundation, www.sca-aware.org/about-sca
 Weisfeldt ML, Sitlani CM, Ornato JP, et al. Survival after application of automated external defibrillators before arrival of the emergency medical system: Evaluation in the Resuscitation outcomes consortium population of 21 million. J Am Coll Cardiol. 2010;55(16): 1,713-1,720.
 Life-saving AEDs often in locked buildings when needed. http://newsroom.heart.org/news/resuscitation-science-tip-sheet-3094258?preview=de34