As I mentioned in my last blog post, the national survival rate for Sudden Cardiac Arrest (SCA) is an abysmal 10%.

This brings up two obvious questions: Why is the survival rate so bad? And what can we do to fix it?

The answer to each of these questions can be summed up with one word: Time. Time to first shock is the key variable in determining if a person survives or dies and how much brain damage is done when SCA strikes.

The brain can only survive for a few minutes without oxygen. As visualized below from data from, brain damage can start just minutes after oxygen stops being delivered to the brain. Severe brain damage begins to happen around 5 minutes and death is likely after 10 minutes.

On the Cleveland Clinic’s website, you will find a gem of information, “You can treat and reverse sudden cardiac arrest. However, emergency action has to start immediately. Survival can be as high as 90% if treatment starts within the first minutes after sudden cardiac arrest. The rate drops by about 10% each minute longer.”

A few years ago, as I contemplated this information and how to simply illustrate the importance of time, I designed a graph in excel that I believe clearly demonstrates the importance of time in the sudden cardiac arrest formula for survival. I recognize that the graph is over simplified but is important to illustrate the following data points:

  1. Time to first shock is the key to sudden cardiac arrest survival
  2. For every minute that passes, the chance of survival is reduced by 10%
  3. Average response times in the US are between 7 and 14 minutes
  4. These three facts explain much the current reality of survival rates at less than 10 percent nationally


Mathematically, the formula is presented as:

Time to first shock is the key to variable we have most control over. It seems simple, but solving for Time is a bit more involved than it may seem. Broadly speaking, reducing Time to shock can be accomplished by focusing on two things: 1) Technology (AEDs and systems) and 2) People (individuals and cultures).

Technology: An AED is the only effective way to restart someone’s heart after SCA. If you don’t have an AED, you are at the mercy of emergency medical services. These brave responders are wonderful but if it takes 7-14 minutes to get to your loved one, you are mostly out of Time. Having an AED and making sure it is functional is obvious, but unfortunately many AEDs are not ready to shock. Remote monitoring systems and program management software are important factors in ensuring your AED is monitored and ready to shock.

People: A functioning AED without someone empowered to use it, is just a bunch of plastic, wires, and batteries. People can be broken down into two categories, individuals and organizations. Ideally, individuals are trained in AED/CPR and First Aid, but at a minimum should be aware and empowered to follow prompts from the AED. Organizations can also drastically increase preparedness by doing simple things to create a Culture of First Responders™.

When Technology and People come together to combat a number one killer, miracles can happen and lives can be saved. In my next blog post, I’ll share how we do this at RescueStat and how you can take what we are learning and apply it to your organization. The solution is known, it’s all about Time!