By Bill Shields, WBZ-TVBy Bill Shields

BOSTON (CBS) – When Pete Sweeney suffered cardiac arrest, his doctors gave him an unusual prescription.

They wanted him to wear a special vest.

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It didn’t take long for him to discover just how valuable that vest could be.

Sweeney, 63, is alive today because of a defibrillator vest that his doctor told him to wear last winter when his heart started acting up.

Pete was watching a Bruins game when he suffered sudden cardiac arrest.

Luckily for him, the vest detected it and shocked his heart back into a normal rhythm.

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“All of a sudden it fired, and I knew right away,” Pete Sweeney said.

The ZOLL Life Vest is worn directly on the skin. Round electrodes monitor the heart, and if there’s sudden cardiac arrest small pads will shock the heart back into rhythm.

Survival rates of sudden cardiac arrest without the vest are grim.

“Without the vest he would most certainly be dead,” said UMass Memorial Cardiologist Dr. Larry Rosenthal. “He has hit the lottery in life. It was fortunate that he was wearing that vest.”

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Since the incident, doctors have figured out Pete’s heart problem and he no longer has to wear the vest.