When Justine Carter stepped on the treadmill for a quick energy boost last May, she never thought it would lead to a near-death experience.
The Utah mother, 33, was fit and healthy — but 12 minutes into her walk, she started having shortness of breath and a pain in her back that penetrated to her chest.
When that was followed by violent vomiting, Carter assumed she’d been hit with a terrible stomach flu.
SOY MILK COULD REDUCE RISK FACTORS FOR HEART DISEASE, RESEARCH SHOWS
"That's where things get a little bit hazy," she told Fox News Digital during an interview.
Carter called her husband and mother-in-law, but has no recollection of the conversations.
"The next thing I knew, I woke up in the hospital."
Her husband and mother-in-law had found her in the bathroom, where Carter appeared to be having a seizure and had very slow breathing.
SLEEPING LONGER ON WEEKENDS COULD LOWER HEART DISEASE RISK BY 20%, STUDY FINDS
Her mother-in-law, Teresa Carter — a nurse at HCA Healthcare’s Mountain View Hospital in Payson, Utah — kept her alive with CPR until emergency medical services arrived.
For 25 minutes, Carter’s heart didn’t beat, and blood only circulated to her body through CPR.
"Everything was pretty ominous," Teresa Carter told Fox News Digital during the same interview.
"She had what we call ‘tombstone rhythm’ on the monitor, which tells us she was having a heart attack, and that her heart muscle was not getting enough oxygen."
At HCA Healthcare’s Mountain View Hospital, doctors confirmed that Carter had experienced a spontaneous coronary artery dissection (SCAD), which is a tear in the wall of a coronary artery that can lead to a heart attack, heart rhythm problems or even sudden death.
Carter’s condition, SCAD, has no known cause or risk factors.
Most patients who have the condition are women in their 40s and 50s who are otherwise healthy, according to the American Heart Association (AHA).
While there is no specific known cause, "scientists think it’s likely that multiple factors may cause SCAD, such as abnormalities in the arteries, genetics, hormonal influences or inflammatory issues," the AHA’s website states.
"Although it is not perfectly clear what causes SCAD, patients are often women – very similar to Justine’s case – who are otherwise healthy," Dr. Mark Bair, medical director of the emergency department at HCA Healthcare’s Mountain View Hospital — the physician who treated Carter — told Fox News Digital.
"In fact, it’s often the case that SCAD patients have few or no risk factors for heart disease at all," he went on.
"Extreme physical and emotional stress are risk factors, as is fibromuscular dysplasia, which affects arterial blood vessels, genetic connective tissue disorders and very high blood pressure."
Carter had no concerning warning signs before the event.
HEART HEALTH RISK FACTORS FOR WOMEN OVER AGE 50
"I just felt like I had low energy that day and didn’t feel up to par — but I just thought it was because it was winter and cloudy outside," she said.
A week after the first heart attack, the day she returned home from the hospital, Carter experienced another cardiac event.
As with the first time, she had chest pain and severe nausea, along with dangerously low blood pressure.
"The second event was every bit as scary as the first," she told Fox News Digital.
Carter was life-flighted to HCA Healthcare’s Timpanogos Regional Hospital, which has a full cath lab team and a cardiothoracic surgeon, in case she needed open-heart surgery.
The cardiac team found that Carter’s original aortic tear had grown in length, causing more swelling and yet another blockage.
WOMEN’S HEART DISEASE RISK COULD BE PREDICTED UP TO 30 YEARS IN ADVANCE WITH ONE BLOOD TEST, STUDY FINDS
"When she arrived at the hospital, her blood pressure was not life-supporting," said Teresa Carter. "Truly, I thought her heart was just going to give out, and was afraid we might lose her."
After restoring blood flow by using a balloon to compress the artery wound, the cardiac team implanted a small heart pump to temporarily relieve Carter’s heart of some of its workload while she recovered.
Today, Carter is back at home, feeling stronger every day.
"Justine is doing great and has a wonderful prognosis with good care and prevention techniques," Bair told Fox News Digital.
When Carter first arrived at Mountain View Hospital’s ER, Bair was worried that she could have ongoing neurological damage because of the 25 minutes that she wasn’t getting oxygen to her brain, he said.
"However, due to the wonderful things that were done in the field, she has fully recovered."
NO CARDIOLOGISTS AVAILABLE IN HALF OF US COUNTIES AS STUDY REVEALS ‘INCREDIBLY CONCERNING’ CARE GAPS
Carter’s mother-in-law starting CPR and the resuscitation efforts of the EMS crews were key to her survival, Bair noted, along with the "heroic steps" performed in the hospital to preserve her brain function.
"Her recovery has been incredible to watch," he added.
After completing cardio rehab, Carter is now able to take her dog on walks, but hasn't yet been cleared to resume her running or hiking activities.
"I was really tired for the first two weeks, and then my energy level started coming up," she said.
"Now I can get through the whole day without needing a nap."
Every three months, Carter visits her cardiologist to make sure her heart is functioning as it should.
Although SCAD can’t be predicted or prevented, Bair emphasized the importance of good lifestyle choices, like eating a heart-healthy diet, engaging in moderate exercise, reducing stress and treating high blood pressure.
"Adults should also get necessary, quality sleep and have regular visits with their physician," he advised. "Tobacco use is also the most preventable risk factor for heart disease."
Carter’s heart attacks have been "life-changing," she said, teaching her the following valuable lessons.
"As women, we tend to put everyone else's needs above our own," she said. "We have to say, ‘This is how I'm feeling and this is what I'm going to do about it.’"
Carter’s heart attacks have helped her realize it’s OK to slow down and let others do things for her.
"Now, if I'm tired, I just tap out."
CLICK HERE TO SIGN UP FOR OUR HEALTH NEWSLETTER
"If something feels ‘off,’ don't hesitate," she advised. "Just call 911, because a lot of things can be prevented if you do that."
Baid also stressed the importance of paying attention to new or different symptoms, including chest pain, abnormal shortness of breath, and extreme weakness or dizziness.
It’s important for people to know CPR and be prepared to use it in emergency situations until EMS arrives, Justine and Teresa Carter agreed.
"Even for non-medical people, it’s such a valuable skill to have," said Teresa Carter. "You will most likely be able to help someone you love."
Although SCAD events usually can’t be predicted or prevented, Carter is determined not to live in fear.
"You can live your life scared of a lot of things, but if you spend every day in fear, you won't enjoy life," she said. "Life is fragile and short, so just enjoy it for what it is."
For more Health articles, visit www.foxnews.com/health
Carter reiterated her gratitude for the team at HCA Healthcare Mountain View Hospital.
"I'm only here because of them," she said. "All I can say is, ‘Thank you.’"