Medtronic—InSync III Cardiac Resynchronization Therapy Pacemakers: Unexpected High Battery Impedance May Occur, Potentially Affecting Device Function

November 18, 2015 | Strategic Insights for Health System


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In a November 2015 Urgent Medical Device Correction letter submitted by an ECRI Institute member hospital, Medtronic states that unexpected high battery impedance may affect the long-term battery performance of the pacemakers listed below. Unexpected high battery impedance may result in the battery's inability to supply sufficient electrical current, affecting device function. Medtronic further states that 12 of 30 devices affected by this problem had reports of unexpected loss of pacing capture. The other 18 devices experienced some form of erratic behavior, including early elective replacement indication (ERI), significant fluctuations in remaining longevity estimates, and inaccurate lead impedances. Medtronic further states that through October 27, 2015, events associated with this problem have occurred in devices with implant durations of 53 months or more. Medtronic has received one report of a patient death, where it is possible, but unconfirmed, that this problem was a contributing factor. Medtronic states that if pacing capture is compromised, some patients may experience a return of heart failure symptoms because of loss of biventricular pacing. In cases involving pacemaker-dependent patients, a loss of pacing capture could result in serious injury or death. Medtronic further states that the issue cannot be mitigated by programming changes or increasing patient follow-up frequency and that the devices are no longer distributed. Current devices have a modified battery design...

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