AIM: Cardiac devices unaffected by handheld metal detectors
Handheld metal detectors used for screening patients at airports did not affect pacemakers or implantable cardioverter-defibrillators in 388 people who participated in a recent study, according to a report published Oct. 31 in the Annals of Internal Medicine.

Jilek Clemens, MD, of the electrophysiology department at the German Heart Center in Berlin, and colleagues did not detect any malfunctions of cardiac rhythm devices during or after exposure to handheld metal detectors, according to the study.

“As security measures have intensified in the past decade, metal detectors are routinely used in many settings to detect ferrous items. Metal detectors create a magnetic field that might interfere with the function of cardiac rhythm devices, and patients with pacemakers and ICDs are often advised to avoid screening with metal detectors because of the risk for electromagnetic interference,” the authors wrote.

The researchers had previously demonstrated that metal detector gates are safe for patients with cardiac rhythm devices, and aimed to assess the risk associated with handheld devices. The FDA reported 44 instances of possible interference between handheld metal detectors or antitheft protection devices and cardiac rhythm devices between 1988 and 1998.

Clemens and colleagues used two handheld metal detectors commonly used in airport security screening to evaluate their effects on 209 patients with pacemakers and 179 with ICDs. Participants were evaluated to ensure their devices were working properly and then they were swiped with a detector for at least 30 seconds, longer than a normal security screening, according to the report. Investigators then evaluated the participant for any abnormalities in the function of their cardiac devices.

“In the assessment of interference between commonly used handheld metal detectors and carious cardiac rhythm devices in a convenience sample of patients assessed at two medical centers, we found no adverse effects from use of handheld detectors on cardiac device function,” wrote Clemens et al. “We aimed to maximize the likelihood of interference by using the highest possible magnetic field of two commonly used handheld metal detectors and by increasing the duration of exposure to 30 seconds per test, which far exceeds the duration of conventional screening.”

Researchers acknowledged that their findings cannot be considered definitive because the study used a convenience sample of patients and devices. Additionally, the research was conducted in isolated clinic rooms, and interference may be possible in airports or other security settings.

“We believe that this scenario is unlikely, however, given that the strength of the magnetic fields is inversely related to their distance from the source,” the authors wrote. “We encourage device manufacturers and other investigators to repeat our protocol in order to more systematically evaluate the interaction between metal detectors and cardiac rhythm devices, and possibly to confirm these findings.”