A small but compelling pilot study indicates that many children with serious congenital heart disease, who are typically urged to restrict their activity, can improve their cardiovascular function and exercise capacity through a cardiac rehabilitation program. Fifteen of 16 children participating in a 12-week rehabilitation program at Children’s Hospital Boston showed significant gains in heart function, researchers report in the December Pediatrics.

Congenital heart defects affect about 8 in 1000 newborns. Due to advances in care, more and more children with these defects are surviving. Many have diminished exercise capacity after the defects are repaired, and some of this reduction is caused by a lack of activity, says Jonathan Rhodes, MD, a cardiologist at Children’s who led the study.

“These kids haven’t exercised much. They’ve been told by coaches, doctors, parents and teachers, ‘Oh, you can’t exercise,’” Rhodes says. “Cardiac rehabilitation is not a component of most pediatric cardiology programs.”

The study enrolled 19 children, aged 8 to 17, who had congenital heart disease severe enough to consider restricting their activity and showed reduced cardiac function on exercise testing. None had findings on exercise testing that might raise a concern about the safety of rehabilitation, such as arrhythmias or chest pain. However, all 16 children who completed the program had undergone heart surgery or a nonsurgical procedure in the past, and 11 of 16 had only one functional ventricle, or pumping chamber. “This was a sick group,” says Rhodes.

The 12-week program consisted of twice-weekly, hour-long sessions combining stretching, aerobics, and light weight/resistance exercises. Activities were tailored to the children’s interests, and included dance, calisthenics, kick boxing and jump rope. Balls, music, games like “capture the flag” and relay races, and age-appropriate prizes were used to keep the kids motivated, and sessions were moved outdoors when weather permitted.

“One game they particularly enjoyed was ‘punch the doctor,’” says Rhodes, referring to a game in which children threw punches at pieces of matting. “A lot of the kids were timid in the beginning, but they were really moving by the end. Being with other kids with heart disease who had never exercised helped melt away a lot of their anxiety. It was quite a metamorphosis.”

Heart rate was checked before each session, and 2 to 3 times during the session. For safety, a pulse oximeter and external defibrillator were available on site, but were never needed.

At the end of the program, 15 of 16 children had significantly improved peak work rate, peak oxygen consumption, or both: their hearts were pumping more blood with each beat, and their muscles were using more oxygen. Improvements were as high as 20 percent on some parameters of function. There were no adverse events.

Rhodes’s team also conducted follow-up exercise testing 1 year after the pre-program tests (about 7 months after program completion). The results, now under review for publication, showed that participants’ cardiac benefits were sustained, whereas non-participating children showed a slight decline in cardiac function. On questionnaires, participants reported exercising more than in the past and had higher behavioral, emotional and self-esteem scores.

Children’s plans to launch a formal cardiac rehabilitation program in fall 2006 or spring 2007, when facilities at Children’s Hospital Boston at Waltham – a new outpatient specialty center in Waltham, Mass. – are complete. Rhodes believes that about two-thirds of children with serious congenital heart disease will be eligible to participate. In the pilot study, fewer than 10 percent of children with reduced exercise capacity had conditions that made it dangerous to exercise.

“With the approval of a pediatric cardiologist, and after careful exercise testing, exercise is generally safe and tolerable for children with congenital heart defects,” he says.