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09-01-2011 | Cardiology | Article

Novel pacemaker suitable for use during MRI


Free abstract

MedWire News: Study findings show that a modified version of the traditional pacemaker continues to function correctly even when exposed to a strong magnetic field during magnetic resonance imaging (MRI).

Modifications made to produce the MRI-resistant pacemaker include limiting the amount of ferromagnetic material used in the device, reducing lead tip heating, and providing internal circuit protection to prevent disruption of the pacemaker's internal power supply.

Lead researcher Bruce Wilkoff (Cleveland Clinic, Ohio, USA) explained that, given the current widespread clinical use of MRI and the growing number of people with cardiac devices, "we find ourselves in need of devices that are compatible with MRI scanning."

Wilkoff added: "This pacemaker system is truly the first to be designed specifically for safe use in an MRI environment."

The study included 464 patients with successfully implanted modified pacemaker systems at centers across the USA, Canada, Europe, and the Middle East.

Of these patients, 258 were randomly assigned to undergo MRI scan at 9 to 12 weeks after pacemaker implantation, and their 1-month post-MRI outcomes were compared with those of 206 control patients who also had modified pacemaker implants but did not undergo MRI.

Wilkoff and team observed no MRI-related complications, defined as an adverse event requiring invasive intervention or termination of significant device function (including sustained ventricular arrhythmias, pacemaker output failure or electrical reset), at 1 month among any patient in either group.

Of note, among the MRI group, one patient reported palpitations and three reported paresthesia arising during MRI. However, the researchers did not classify these occurrences as MRI-related complications as they resolved within 24 hours of the MRI and required no invasive action.

Furthermore, "these events are typical events seen among patients who undergo MRI," say Wilkoff and team.

Writing in the journal Heart Rhythm, the researchers conclude: "These results indicate that this pacemaker system can be used safely in an MRI environment when used in accordance with its labelling."

MedWire ( is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2011

By Lauretta Ihonor

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