NEW YORK (NBC NEWS) — Unlike a heart attack which occurs when one or more coronary arteries are blocked, a sudden cardiac arrest occurs following a short circuit in the heart. According to the American Heart Association, this electrical problem strikes more than 350,000 people each year-about 1,000 every day.

The only way to prevent a sudden cardiac arrest is with the use of an implantable defibrillator which shocks the heart back to a normal rhythm. Until recently, no test can predict when a sudden cardiac arrest will happen and who’s at high risk for needing a defibrillator.

“By the time cardiac arrest happens, it’s way too late,” said Dr. Sumeet Chugh, associate director of Genomic Cardiologist Cedars-Sinai Heart Institute. “Every minute that passes there’s a ten percent chance of dying. Ten minutes and you’re gone.”

For decades, Chugh has been working to solve the problem of predicting the unpredictable. Now, after studying thousands of patients, he has discovered a solution that involves an inexpensive century old test called an electrocardiogram, or EKG, which displays the heart’s electrical activity.

Chugh looks at six data points on an EKG tracing that reveals important information ranging from how fast the heart is pumping to its electrical activity. This key information is then used to assign a risk score ranging from zero (normal) to six (severe). A score above four indicates a 20-fold increase in the risk of suffering a cardiac arrest requiring a defibrillator.

The hope is that in the future, anytime a patient receives an EKG at a doctor’s office, it will show their risk of having a sudden cardiac arrest, according to NBC News Medical Correspondent Dr. John Torres. If the score is high, then a person will be referred to a cardiologist for further evaluation which may require an implantable defibrillator, even if they are currently healthy.Read more at NBCNews.com