When you meet six-year-old Mackenzie “Mack” Zashut, it’s difficult to believe that he has had four open heart surgeries. He buds with energy and curiosity.

Mack was born without a right ventricle, the heart chamber that controls the lungs’ blood supply.

When she was 23 weeks pregnant, Stephanie Cote of Lewiston had an ultrasound at the high risk OB/GYN center at Maine Medical Center in Portland. The images showed that her child would be born with a defective heart.

Cote said Mack’s heart had “plumbing that was a mirror image of a normal heart.”

When he was two days old, Mack had a shunt inserted during his first open heart surgery, step one in the process of reconstructing his heart. At three months, he had surgery to revise the shunt, and at six months he had a procedure to adjust the blood supply to his lungs. At age 3, he visited Maine Medical Center for his last open heart surgery, to complete the heart reconstruction.

Following Mack’s first surgery, Cote got in touch with Precious Hearts, a support group for families of children with heart disease based at Maine Medical Center. She exchanged support and experiences with other Maine parents over the Internet.

A Maine Medical Center cardiologist explained to Cote that every heart defect unique and cautioned her against searching the Internet for heart diseases since nothing she would find would apply to Mack’s condition. Although she sought out information about heart defects, Stephanie said her primary research covered the basics: To learn how a normal heart works. “I wouldn’t have been able to understand what a defective heart would do if I didn’t understand how a normal heart functions.”

She encountered information that scared her: 25 to 30 years ago, children born with Mack’s condition did not stand a chance for survival and were sent home to die.

“Research is huge,” she said.

Now, she speaks on behalf of the American Heart Association and was featured in an AHA video.

The three years of surgery were “nerve-wracking,” Cote said. “Mack has always returned home within seven days of his open heart surgeries, which is amazing. Most people are nauseous when they come out of anesthesia; he asks for pizza.”

Mack is part of a hockey family but will never be able to play the sport or do any other contact activities. The doctors indicated that his ability to keep up with his peers will decline as he grows older because his heart works with fewer ventricles. However, there is no risk Mack will ever be inactive. He plays T-ball, tennis and golf.

And “Mack likes to dress up like Tom Brady and tackle trash cans,” Cote said.

He started kindergarten this fall and enjoys it. His favorite activities include drawing and playing soccer, horseshoes and riding on scooters in gym class.

When he grows up he wants to be a construction worker, a traveler and a college student.

Mack’s heart may lack parts, but it does not lack a passion for life. Delightful and good-humored, he ended an interview with an honest “I’m bored.” Then he went out to join his friends in play.