By Andrea Lucia

LEWISVILLE (CBS11) – John Copeland has seen plenty of heart attacks in his 25 years as a Lewisville firefighter and paramedic.

“A lot. A bunch. Many. Many. You would think that would clue me in when I’m having my own, right?” he says.

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When he felt a sharp pain in his arm, though, while exercising in March at the North Central Texas College Fire Academy, he ignored the warning sign.

“The whole time I thought.. How did I tear my shoulder running sprints? How do I have an arm injury?” he recalls.

John Copeland (CBS11)

The Marine ordered his fellow instructors not to call an ambulance, but the off-duty paramedics didn’t listen.

“I’ve always been in top physical shape, so you just think you’re gonna beat it,” he said. “The entire time my ego was trying to kill me.”

At Medical City Denton, interventional cardiologist, Dr. Atif Yousuf was ready and waiting when Copeland arrived.

“He declined really fast, really quickly,” he said.

Copeland saw the urgency in the staff’s faces and understood he was in the position he’d seen his own patients in before.

“I just had seconds. I literally had seconds to live, and they were going,” he said.

“He started having cardiac arrest on our table,” said Dr. Yousuf, who worked alongside others to try to restart Copeland’s heart.

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“We had to shock him multiple times, ten times,” he said.

“They lit me up,” said Copeland, who lost consciousness after the second attempt.

For 15 minutes, he says he wavered somewhere between life and death.

When he opened his eyes again, he saw someone in a surgical mask looking over him.

“Dude, you made it,” he remembers hearing, much to his relief.

Four months later, Copeland returned to personally thank the men and women who saved him.

“This is the only life we have. This is not a practice,” he said.

Today, he is back at work, determined to regain the level of physical fitness he’s always been so proud of and grateful for every extra day he gets.

“I’ve already died once… You gotta really make it count while you’re here,” he said.

Dr. Yousuf says half of all heart attacks are due to genetics, not anything you can control.

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He suggests people learn their family histories and never ignore the symptoms.