A defibrillator vest is saving lives in Oklahoma.  It's designed for people who have a weak heart or survived a heart attack. One Oklahoma man says the LifeVest saved his life twice.

It's been around for a few years now, but doctors say many heart patients don't even know it exists.

Two months ago Michael Hopkins went to the doctor because he was having trouble breathing.

"He gave me an EKG and he said, 'Well you have flunked this. Your heart is in defibrillation. Go to the emergency room now,'" said Michael Hopkins, heart patient.

After about a week of treatment, the doctor presented Hopkins with this LifeVest.  It detects your heart rate and if it stops beating, then the vest will automatically shock your heart.

"We see a lot of our patients coming into the hospital with heart attacks, going home and then dying suddenly just a few weeks later, which is completely tragic and 100 percent preventable," said Dr. David Sandler, Oklahoma Heart Institute.

Hopkins knows first hand it is preventable.  Less than 12 hours after he was discharged from the hospital, he had a heart attack.

"The alarm went off, so I pressed it and it said get ahold of a doctor and I didn't do that, which was rather foolish," Hopkins said.

An hour and a half later - another heart attack. His daughter found him sitting in his chair.  He was on the brink of death.

 "When she came back, my head was back and I was shaking," said heart patient Michael Hopkins. "Without that LifeVest I would not be here right now speaking to you."

Doctors wait 90 days before implanting defibrillators.  This gives the patient's heart a chance to recover before the surgery.

During that waiting period, the LifeVest could be the difference between life and death.

 "I think that every single patient with a heart function below 35 percent, discharged from a hospital without a defibrillator should at least be offered this therapy," Dr. Sandler said.

 "If it's offered to you, don't refuse it," Hopkins said. "I can't say enough about how lucky I am and I feel wonderful now."

Hopkins now has a defibrillator implant.

The LifeVest is the only wearable defibrillator.