No threat to pacemakers from iPods: Study

Here is relief for gizmo-lovers with a heart condition - no, "electronic noise" from iPods does not cause cardiac pacemakers to trip, a new study says.

Researchers at Children's Hospital Boston were intrigued by a widely reported study last May that concluded errant electronic noise from iPods could cause implantable cardiac pacemakers to malfunction.

This just did not sound right to the hospital's cardiac electro-physiologists who have seen hundreds of children, teens and young adults with heart conditions requiring pacemakers, ScienceDaily reported.

"Many of our pacemaker patients have iPods and other digital music players, and we've never seen any problem," said Charles Berul.

"But kids and parents bring up this concern all the time, prompting us to do our own study."

While last year's study was done in patients averaging 77 years, the average age in the new study was 22. All patients had active pacemakers or implantable cardioverter-defibrillators (ICDs), which were tested against four digital music players - two kinds of iPods (Apple Nano and Apple Video), SanDisk Sansa and Microsoft Zune.

All patients were lying down during the tests, and each digital player was placed directly over the pacemaker or ICD.

The study, published in the latest issue of the journal Heart Rhythm, found there was no interference with intrinsic device functioning - patients' EKG (electrocardiographic) recordings showed no change in any of 255 separate tests, and no patients had symptoms.

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

However, in 41 percent of patients, the music players interfered with telemetry, or communications between the programmer and the pacemaker or ICD itself. The programmer is a computerised device used by physicians to check and recalibrate the pacemaker/ICD - patients do not carry it.

This interference, picked up in 29 of 204 tests, however, went away when the digital player was moved six inches or more from the device, and did not compromise device function.

Patients should not use digital music players while the doctor is trying to reprogram their device, the researchers concluded.

Berul and colleagues 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 said. "That's why we suggest the precaution of keeping it at least six inches away."