EMSA's cardiac arrest survival rates are four times the national average.
EMSA paramedics say they are able to keep 45 percent of cardiac arrest patients alive because they work like a pit crew.
When someone is having a heart attack and calls 911, EMSA says dispatchers will talk a bystander through CPR or how to use a defibrillator.
Once paramedics arrive, they jump into action with specific roles: One will do ventilations, while another performs CPR and another oversees the process.
EMSA Clinical Educator Scott Williams said EMSA practices this pit crew-like response often.
"The best outcomes we've seen are whenever people are taking the initiative to do at least compressions-only CPR," Scott Williams said. "Grab an AED, put it on that patient and see if it's going to give them a shock."
911 dispatchers will also advise to keep the patient as cold as possible to preserve brain function.
Paramedics will then stabilize the person, bringing them back up to normal temperature after cardiac arrest.