Calls made on cell phones do not affect hospital medical devices, Mayo Clinic researchers said, but store anti-theft alarms might make implanted heart devices misfire.

In a study published in the March issue of Mayo Clinic Proceedings, researchers say tests showed normal use of cell phones caused no noticeable interference with patient care equipment. Two cell phones were involved in the study, using different technologies from different carriers, and 192 medical devices. Three hundred tests were performed over a five-month period in 2006, without a single problem incurred.

Currently, cell phone bans inconvenience patients and their families who must exit hospitals to place calls. The study's authors say the findings should prompt hospitals to alter or abandon their bans on cell phone use. Mayo Clinic leaders are reviewing the facility's cell phone ban because of the study's findings, says David Hayes, M.D., of the Division of Cardiovascular Diseases and a study author.

But unlike the cell phone study, a portable CD player caused an abnormal electrocardiographic (ECG) reading when a patient used it near one of the leads of the device. The recording returned to normal when the CD player, which the patient was holding close to the ECG lead, was turned off.

Technology also can threaten implantable rhythm devices such as pacemakers and defibrillators outside the hospital setting, according to a journal report. The report outlines two cases of retail stores' anti-theft devices causing people's heart devices to malfunction.

In an accompanying editorial, John Abenstein, M.D., of Mayo Clinic's Department of Anesthesiology, addresses the journal reports relating to the impact of technological devices on patient care equipment. Dr. Abenstein says the risk of some technological devices upsetting the function of patient care equipment in hospitals appears to be small. The Food and Drug Administration (FDA) should take a more explicit stand on the matter, he says, so that health care facility policies can be altered when appropriate.

Articles are available online at http://www.mayoclinicproceedings.com .