Dr. Catherine Allan wears lots of hats. She's the medical director of the Cardiac Intensive Care Unit (CICU) at Boston Children's Hospital and associate program director of SIMPeds, Boston Children's Simulator Program. She's also a wife, mom, triathlete and a congenital heart defect survivor.

"I was born with tetralogy of Fallot with pulmonary atresia," says Allan. "But I grew up at a time when open-heart surgery happened much later than it does today, so I didn't have surgery until I was 8."

She still remembers the dramatic change in her quality of life after the two surgeries to repair her heart defect.

"Before surgery, I couldn't keep up with other kids my age, but after the surgeries, I was suddenly able to live a normal life and was very active through the rest of my school years. I never felt like I was significantly limited by my health issues."

Allan began riding horses as a girl and continued through college, joining an intercollegiate equestrian team. She's continued to be very active through adulthood.

"I started doing triathlons about four years ago," she says. "I'm slower than most and it's taken me longer to get to the level I'm at than someone without a congenital heart defect, but I've learned that I can actually do much more than I thought. That's really reassuring and reaffirming."

Staying as active as possible is a message she shares with the heart patients she cares for.

"Some kids have greater limitations than others, but I encourage parents to let their kids do what they can, within the restrictions their doctor recommends. The more active they are, the heathier they will be."

Shaped by her experiences as a patient and drawn to science and research, Allan knew she wanted to be a physician from an early age. She loves developing close relationships with patients and their families.

"I'm really lucky to be able to do this job," she says. "As someone who has lived through the experience of heart surgery and really thrived, it's an incredible privilege to help kids and have an impact on their lives."