“That was when the alarm bells went off, though I couldn’t, even at that moment, imagine I was having a heart attack,” says Casalan, president of the UPS Store Inc. and a single mom to two boys who were 6 and 7 at the time. After all, she was just 47, active, and in generally good health. “And why would I think I was having a heart attack without chest pain?” 

Casalan eventually got herself up and to her mom, who happened to be visiting that night, and from there “it was a total of about five minutes between the realization that I could be having a heart attack to unconsciousness.” Turns out she was suffering from full blockage in her left ascending artery—prompting a heart attack known as a “widowmaker”—which has just a 12% survival rate outside of hospitals for women. (Doctors have since theorized that it could’ve been brought on by having had an “overly inflamed” heart after a bout with COVID.)

What followed were several cardiac arrests—sudden stoppages of the heart—that required resuscitation, and being placed on life support for her heart and lungs. 

“My family was advised to make their preparations and say goodbye,” she tells Fortune, and they were informed that her best chance at survival would come from a heart transplant. She was placed on a waiting list.  

Today, Casalan, who has headed the 5,700-store network since 2021 and who, just days before her health crisis, had shared the stage with the company’s CEO and CMO at a conference and was feeling “ready to take on the world,” has come out on the other side of a long road to recovery dotted with setbacks. But she’s also eager to talk about it all, as “helping women work,” especially moms, is a “personal passion,” she says—as is health equity.

“So it’s just a great extension of two things that I care so passionately about,” Casalan, 49, now a board chair with the American Heart Association of Chicago, says. “How do we model for women how they can be successful in the workplace and be successful moms? Be successful single moms? You have to be a healthy mom to be able to do all of those things.”

Below, Casalan, shares just a few of the valuable lessons she learned from her near-death experience—about leadership, parenting, and setbacks. 

Have some faith in medicine

Casalan remained on life support for many days and suffered initial setbacks—including when she developed a blood clot that wound up cutting off blood supply to her leg and foot, requiring extensive surgical efforts to save them. She stayed in the hospital for over two weeks. 

“I was sent home with a life vest, which is an external defibrillation device that anticipates your higher risk of cardiac arrest,” she says, and entered cardiac rehabilitation. “The idea was, hey, if you can survive the first 90 days, maybe we can kind of get past this transplant idea…And I’m here today to tell you that I have my own little heart.”

Casalan has recovered the vast majority of her heart function. “My message there is: Science matters. Medication matters.” At a recent appointment with her doctor, she was told, “Listen, you can do all the lifestyle things. You can do all the intervention things. But the medication and the science is what got you here.”

Listen to your body 

Since her heart attack, Casalan has discovered, through the emerging science of genomic risk analysis at GenomicMD, that she does indeed carry a 70% higher than average risk of cardiovascular disease. Had she known, she might’ve lived differently years ago.

“I lived in New York City for 15 years. I worked in the fashion industry. I was single. I was living the most extraordinary and full and interesting life, sustaining myself on a diet of caffeine, bagels, M&Ms and Diet Coke,” she says. In those days, she recalls, her mindset was one of, “I’m just all in on everything and everyone and everywhere, and I don’t have to take care of myself.” At the same time, she had “a little bit of the typical mom piece and the typical female leader piece, like, ‘I’m going to take everything on.’” Eventually, that meant adding a “highly contentious divorce” into the already stressful mix.

What Casalan has come to understand about doing it all and taking care of everyone but yourself is this: “If you don’t listen to your body, it will speak for you eventually…My invincible persona was re-educated.”

Good leaders are vulnerable—and know how to roll with setbacks

Casalan had some big lessons sink in when she eventually returned to work. “For my team to have confidence and understand where we all were at the time, I had to be very honest about everything—including what my limits were. And that was very difficult.” What she believes that fostered, though, “was an openness from us as a team to talk about the realities that we’re all managing and how we can help and support each other.”

The biggest change in her leadership style, however, “is how I consider setbacks,” she says. That’s because she faced even more during her recovery—namely, 70% blockage in another artery, her left main artery, discovered during a stress test at the doctor’s office and prompting immediate robotic-assisted bypass surgery. 

“That one was hard,” she says. “I think I had always anticipated that there would be some type of setback…[but] that’s not what I expected, for my healing to kind of be picked up and off of the rail.” 

As a leader, she shares, in her aforementioned “indestructible phase,” she had a tendency to “run through all obstacles,” believing, “there’s no constraint we can’t eliminate. We put our minds to it, and we can do it.” But her second blocked artery changed her mindset.

“Now the way I think about setbacks is to say some of them are very far out of our control and very far out of our influence,” she says. And she’s more apt to consider a range of options about how to go forward—with the understanding that they may need to be a pivot to a different way of thinking. “I think that it has opened up a lot of creative conversations,” she says. “Before we just either give up or keep going, let’s really spend the time thinking about, what does this setback mean, and how can we respond to it? And giving the time and grace to do that has been meaningfully different.” 

It really does take a village

When Casalan was unconscious and being taken out of her home by stretcher the night of her heart attack, her two boys—both on the autism spectrum—were unfortunately not asleep. “They did see the paramedics take me away, and it’s still, you know, it’s still a moment for them,” she says. 

But they were quickly comforted and cared for by many people in their lives. “I am extremely fortunate. I come from the line of cast-iron women, they are quite formidable,” she says. That includes her sisters who came from the East Coast, one staying for eight weeks, and her mother, who wound up staying for a year. Plus, she has “an extraordinary nanny.” 

Despite the crisis at hand, she recalls, when it came to her kids, “the most important thing was that they were surrounded by love and a sense of safety and optimism. We didn’t really talk about what had happened until I was okay—like, we didn’t talk about the severity of what had happened.” They have since—just as they recently attended a local fire and rescue open house day, where they were all able to personally thank the paramedics who were there that night, bringing some closure. 

Now, she says, she openly talks about her brush with death—especially with her younger son, who, coincidentally, had corrective heart surgery at 10 months old. Sometimes they “compare scars,” she said, and they recently did an American Heart Association event together.

Both boys are even able to joke about it all. “They’re funny,” she says. “They’ll say, ‘Well, Mom, you know you only live once! Except you.’”

More on heart health:

• Will you have a stroke? These 17 factors—10 just for women—can be predictors, say new prevention guidelines
• Sleeping in on weekends could cut your risk of heart disease by up to 20%, new study shows
• When’s the last time you were angry? Just recalling the experience may be detrimental to your heart health, study says