Two men in their 40s go into cardiac arrest during 3M Half Marathon

It was a pretty brisk Sunday morning, but not too brisk for a great turnout. Officials say the 3M Half Marathon had its second-largest registration in the race's history, but it had a couple of very frightening events.

ATCEMS says its crews responded to two separate cardiac arrest calls, one at the finish line and another at East 32nd and Duval Street. ATCEMS says both of the men were in their 40s.

Dr. Craig Siegel, director of sports cardiology at the Heart Hospital of Austin at St. David's Round Rock Medical Center, says if you witness the signs of cardiac arrest pay close attention.

“You may see a runner beginning to stagger, perhaps not alert as he or she had been. It's often mistaken for someone who is just fatigued or tired. We may see an individual collapsed or gasping for air. Sometimes it's confused with seizures or convulsions,” Siegel said.

Siegel says with cardiac arrests, the key is early recognition and early response. 

“You need to assume sudden cardiac death until proven otherwise," Siegel said. "The key is early recognition and early response, so early application of CPR and prompt defibrillation with an AED is really the key to getting these individuals out of the hospital alive. In general, the instance, the sudden cardiac death in a marathon or half marathon on average is about 1.5 per 100,000 people."

RELATED: ATCEMS: Two men suffer cardiac arrests during 3M Half Marathon

He says even well-trained athletes are at risk so he advises everyone who wants to compete get checked out by a physician beforehand.

“We want people to do what they want to do, safely," Siegel said.

As for the two men, another doctor was running behind one of the victims and says she stopped to help assist with CPR in progress. EMS arrived minutes later and took over his care.

She stayed with his wife until he was transported to the hospital then the doctor finished her last two miles.

“This really highlights the importance of CPR training in the community,” Siegel said.

ATCEMS say both victims had to have their pulses return and were transported to the hospital.

"Events like this tend to occur in the last quarter of the race. It's human nature you want to finish you've invested a lot of time and energy into training for and preparing for the race so you don't want to quit," Siegel said. "So you may ignore some indications or signals your body is sending you.”

As for recovery, Siegel says he's seen patients that have had cardiac arrests, heart attacks, and bypass surgery and almost all of them have no recollection of what happened or much warning.

He recommends going through cardiac rehab and for them to perform a maximum stress test.