"My heart was not able to meet the needs of my body," says Marks, now 28 and a physician herself.
An MRI revealed that Marks had probably suffered a bout of viral myocarditis. In trying to rout the virus, her immune system had inadvertently attacked her body, wreaking havoc on her heart.
After leaving the hospital on medications, Marks initially felt peppy enough to jog up the stairs to her apartment. But it soon became clear that she had no stamina or endurance.
"I went for a run and made it only two blocks before I had to stop. I could tolerate day-to-day activities, but anything beyond that was too much. Some people improve over time, but I was not one of them. My heart was damaged permanently."
Junior year was tough. Many friends were studying abroad. She could hang out with the softball team but only watch the games. She threw herself into schoolwork and research projects. "I don't like to be idle," Marks says. "I was doing my best to put up a positive front, not to let anyone know what thoughts were going through my mind."
That summer, back home, she "crumbled," falling into a depression. But senior year, Marks rallied. Her friends were back on campus, and she made an effort to "focus on the positive things" in her life. Inspired by her mother, a pediatrician, and despite her heart ailment and Type 1 diabetes, Marks applied to medical school.
"It was a lifelong dream," Marks says, "and hopefully I'll be able to use what I've learned through my own struggles to help someone else."
Marks wanted to stay close to home and chose Thomas Jefferson University. All the while, her heart was failing, making her less able to exert herself. The first two years, heavy on book learning, were manageable. But the third year, heavy on rotations and seeing hospital patients, pushed Marks to her physical limit.
By then, Marks had decided to see Susan Brozena, an advanced heart failure specialist at the University of Pennsylvania. Brozena convinced Marks that she needed to slow down, conserve her energy. Says Marks: "She was the first to make me realize how sick I was, but she also let me know we had options for treatment."
In her fourth year, Marks got the pediatric residency she coveted at Nemours/Alfred I. duPont Hospital for Children in Wilmington. She loved the place, the work, and her colleagues, but was feeling exhausted. Then she succumbed to a gastrointestinal illness that threatened her critical diabetes regimen. Her health under assault on many fronts, she was taken to Penn's cardiac unit. There, Brozena convinced Marks that she needed a transplant.
Marks was listed for a donor heart in August 2012. Last August, after a 345-day wait, she received the healthy heart of 39-year-old local man who died of a seizure. A week after leaving the hospital, she was working out on an elliptical trainer. A month after surgery, she was driving and visiting friends. Six weeks after the transplant, she was running ("so exhilarating!").
Early last month, Marks returned to her rounds at duPont. She walks with a zip in her step, is determined to catch up, and has more passion for medicine than ever.
"Most people get to be a patient or a doctor, but I've experienced my heart transplant from both sides," she says. "I've seen firsthand what my physicians have done that has been tremendously helpful or harmful."
Marks has also organized Team Brynn Tin Tin to raise money for organ-donor awareness at the Gift of Life Dash, which starts at the Philadelphia Museum of Art on April 13.
"I want to celebrate the gift I've been given," says Marks, who is grateful to family and friends for "never letting me give up" and who is writing a book about her journey (working title: Not Only Tin Men Need Hearts). "The way I look at it is, if my donor hadn't made that decision, and if his family hadn't supported it, I wouldn't be here right now."
More than 121,000 people in the U.S. are awaiting organ transplants. Of those, about 3,700 need heart transplants; 689 of those are age 34 or younger.
Every day, 79 people receive transplants, and 18 people die while waiting.
One organ donor can save as many as eight lives.
No religions object to organ transplantation. Age and past medical conditions do not keep you from being a donor. Giving does not compromise your care nor does it preclude an open-casket funeral or cost anything.
Pennsylvania residents can register as donors at www.donatelifepa.org or 1-888-366-6771. In New Jersey, donatelifenj.org or 1-800-742-7365.
"Well Being" appears every other week, alternating with Sandy Bauers' "GreenSpace" column. Contact Art Carey at firstname.lastname@example.org. Read his recent columns at www.philly.com/wellbeing.