IPods OK with pacemakers: study

(CBC) - Concerns over iPods causing cardiac pacemakers to malfunction appear to be unfounded, researchers at Children's Hospital Boston said Monday.

Cardiac electrophysiologists at the hospital launched their study after widely reported research last May concluded iPods did in fact interfere with pacemakers. The specialists have seen hundreds of children, teens and young adults with heart conditions requiring pacemakers, and questioned the results of that study.

"Many of our pacemaker patients have iPods and other digital music players, and we've never seen any problem," Dr. Charles Berul, director of the pacemaker service at the hospital, said in a release. "But kids and parents bring up this concern all the time, prompting us to do our own study."

Between September and December 2007, Dr. Gregory Webster, a cardiac fellow in training, along with the electrophysiology nurses and physicians, ran tests on 51 patients.

While last year's study was done on patients averaging 77 years of age, the average age in the Boston study was 22 (ranging from six to 60). Their pacemakers were tested against four digital music players - two kinds of Apple iPod (Nano and Video), SanDisk Sansa and Microsoft Zune. Each digital player was placed directly over the pacemaker.

The study, published in the April 2008 issue of the journal Heart Rhythm, found no change in patients' EKG recordings (which records the electrical activity of the heart) in any of 255 separate tests, and no patients had symptoms indicating a problem.

"This provides reassuring evidence that should allay the fears of people using iPods and other digital music players," says Berul, the study's senior investigator.

Still, the doctors caution that in 41 per cent of patients, the music players interfered with communications between the programmer and the pacemaker. The programmer is a computerized device that doctors use to check and recalibrate the pacemaker during appointments.

The study recommends patients not use digital music players while the doctor is trying to reprogram their device.

The original findings of interference with the pacemaker, conducted by doctors at Michigan State University, are published and updated in the same issue of Heart Rhythm. The editorial discusses possible reasons for the discrepancy between the two studies, which mainly relate to the testing methods and interpretation of the pacemaker recordings.

Berul and colleagues say they are reassured by their own findings, but acknowledge that their testing was only short-term.

"We can't conclude that it's completely safe to have an iPod right on top of the device for hours at a time," Berul says. "That's why we suggest the precaution of keeping it at least six inches away."