Infants can benefit from a treatment that burns off a small amount of heart tissue to regulate uncontrolled, rapid heart rhythms.
The treatment, called radiofrequency catheter ablation, has been used to treat abnormal heartbeat called tachycardia, mostly in older pediatric patients and adults. But a national study of its use in infants found that they, too, can benefit, according to research published Monday in Circulation: Journal of the American Heart Association.
The study found the ablation is about 90 percent effective.
The treatment has been around since the 1980s, said Primary Children's Medical Center physician Dr. Susan Etheridge, who uses the procedure on children "usually where more conventional methods like medicine have failed to get rid of tachycardia or keep it under control." She hasn't used it on newborn patients, she said.
The ablation uses catheters that look like spaghetti threaded into the heart to reach the tissue where the electrical signals have gone awry. Then radio frequency energy powered by an external generator is used to kill a small piece of tissue.
The procedure carries risks, some of them serious, Etheridge said.
For some children, like Caitlin Clawson, 14, the ablation beats the alternative. The girl had her first tachycardia episode in sixth grade. As she reached puberty, the episodes were more frequent and included fainting, tunnel vision and black spots in her vision. It became harder to function, so doctors put her on beta blockers, which controlled her heartbeat better, but she started having nightmares and was exhausted all the time, her mother, Robin Ayers, said. When they tried to wean her off the medication, the tachycardia increased, but her parents and doctors agreed that she was not a good candidate for lifelong medication.
Sept. 13, Etheridge ablated her heart and Clawson came home the next day. She now takes a chewable low-dose aspirin every day and is on her school lacrosse team. She's also resumed swimming, something she used to do avidly.
Some children must use medicine the rest of their lives— and it doesn't always keep the condition in check. Tachycardia itself can range from frightening "heart racing" to sudden death. Eventually, it can lead to congestive heart failure.
The rapid pulse is extreme in some cases — up to 300 in infants and 250 in teenagers.
In the 1960s and '70s, the only cure for superventricular tachycardia was to open the chest and change the circuitry with cryoablation, where the target tissue is frozen. Recovery was much longer and the radiofrequency ablation has become the standard for many arrhythmias in pediatric patients.
Safety concerns have been a major barrier, because arrhythmias in infants cause more problems and are harder to treat with medications.
The doctors reviewed records from a national pediatric registry to note why the procedure was used on infants, its complications and efficacy. They compared 137 infants, ages 2 weeks to 18 months, to 5,960 patients 19 months to 21 years old. They found the treatment was used for very, very sick infants where other therapies had failed.
Researchers found no statistical difference between the two groups as far as its effectiveness, although the trend slightly favored older patients. They found little difference in the complication rate between the groups. But lead author Dr. Andrew W. Blaufox, assistant professor of pediatric cardiology at the Medical University of South Carolina, said, "I am not certain that we would have found no difference between the two groups if there had been 100 more infants."
Weight, age, the size of the medical center where the procedure occurred and whether or not the patient had a heart defect had no effect on the success.
E-mail: lois@desnews.com