The odds were against Mark Peters' sitting across the table from me and boasting of the impressive crimson scar under his shirt.

Most who suffer cardiac arrest do not make it to the hospital, let alone reemerge whole. But here he was, spike-haired and 23, enthusing about his good fortune, a rainbow of rubber "cause" bracelets wobbling around his animated wrists.

The one that matters in this story was red, for the Gregory W. Moyer Defibrillator Fund, which aims to put automated external defibrillators where they're needed most desperately.

Moyer, Peters' boyhood pal, died at halftime during a high school basketball game in 2000 because no device was on hand to reset the rhythm of his heart - not in the brand-new Monroe County school, not in the first ambulance, which took a half-hour to respond.

Moyer - seemingly invincible at 6-foot-3 and 220 pounds - died at age 15.

After recovering from the shock, Peters built a memorial Web site and ever since has returned home to attend dinners and auctions to raise money to ensure that others suffering cardiac arrest would have a better chance.

What Peters could not have known was that eight years after his friend's death one of those devices would save his own life.

Just in time

He had finished his day job - the Temple marketing grad works in business development for eLeadCorp in Berwyn - and was moonlighting as a personal trainer at the Philadelphia Sports Club in Radnor.

It was 6:45 p.m. on Wednesday, Feb. 25. He was stretching with a client, a woman training for crew season. And something felt wrong, "like I was in some kind of slump. That's not usually me."

He asked the woman to alert a trainer. Then he hit the floor.

The smack of his 6-2, 230-pound frame corrected his heart's arrhythmic pattern. When he came to, he was vomiting violently. Then his heart went off again.

That's the last thing he remembers for a while. What he has learned is that everyone at the sports club sprang to action, rolling him on his side, scooping out his mouth. Someone called paramedics. Someone prepared to administer CPR. Someone grabbed the defibrillator.

And by the time his coworkers were ready to start reviving him - not five minutes had passed - Radnor and Narberth rescuers arrived.

Sheetal Chandhok, an electrophysiologist at Bryn Mawr Hospital who treated Peters, said his youth, his physical condition, and the quick response were what had saved him.

A rare save

"Very few people make it out of the hospital alive," Chandhok said. "Single digits make it to full recovery."

But less than 48 hours after doctors put him in a coma to help his brain recover, Peters woke in his hospital bed surrounded by family, and was able to scribble a note, asking what day it was.

When he heard it was Friday, he wrote down another thought: "I have a date tonight."

He had to reschedule, he informed me Monday as we sat at Barnes & Noble on Temple's campus. The makeup date, he said, went "very well, in fact."

He has lost 30 pounds, but otherwise he's in remarkable shape. By Sunday he'll have been cleared for all activities except weight lifting, which he can resume in a few weeks. Under his shirt a defibrillator checks his heartbeat, as his doctor continues to investigate why he went into cardiac arrest.

Another big change, Peters said, is on the inside: a sense of what's important. He won't return to work at the health club. With his free time, he's going to join the Moyer family in drumming up awareness of the need to make defibrillators readily available.

There's much work to do. Benjamin Abella, who directs clinical research at Penn's Center for Resuscitation Science, recently toured Center City looking for lifesaving AEDs. "There were not as many as as we'd hoped," he said. Why?