Safety Alert Or Field Safety Notices for Sigma® implantable pacemakers

According to Medicines and Healthcare products Regulatory Agency, this safety alert or field safety notices involved a device in United Kingdom that was produced by Medtronic.

What is this?

Field safety notices are communications sent out by medical device manufacturers or their representatives in relation to actions that they may be taking in relation to their product that is on the market. These are mainly for health workers, but also for users. They can include recalls and alerts.

Learn more about the data here
  • Type of Event
    Safety alert / Field Safety Notice
  • Event Number
  • Date
  • Event Date Posted
  • Event Country
  • Event Source
  • Event Source URL
  • Notes / Alerts
    Data from the United Kingdom is current through April 2019. All of the data comes from the Medicines and Healthcare products Regulatory Agency, except for the categories Manufacturer Parent Company and Product Classification.
    The Parent Company and the Product Classification were added by ICIJ.
    The parent company information is based on 2017 public records. The device classification information comes from FDA’s Product Classification by Review Panel, based on matches of recall data from the U.S. and the United Kingdom.
  • Extra notes in the data
    Failure of interconnecting wires within the pacemaker may cause:loss of pacing output from atrial and/or ventricular ports
    premature battery depletion
    intermittent or total loss of telemetry
    high lead impedance values
    loss of rate response
    device reset to manufacturer’s default settingsMedtronic has advised MHRA that some Sigma® pacemakers from the above model ranges may be subject to failures which could result in any of the behaviours listed on page 1. Medtronic issued letters to clinicians about this issue in November 2005 (See Appendices 1 and 2).Medtronic’s analyses of 19 returned Sigma® pacemakers has identified a failure mode where separation of interconnecting wires between certain electronic components, can seriously affect the performance of the device.Analysis has identified that the wire separation is associated with the use of an incorrect cleaning solvent during circuit board manufacturing that contained an antioxidant. The solvent, which was only used for a limited manufacturing period, resulted in surface contamination of electrical connection areas prior to wire bond connection. Extensive testing and analysis by Medtronic has now confirmed that use of this cleaning solvent can lead to a reduction in strength of the wire bond connections and these connections may separate over time. No mean time to failure has been established for this failure mode however there have been no failures less than 17 months post implant.There is no provocative testing that can be performed to identify when any of the affected devices may fail.Failure rates are currently low at approximately 0.05%. To date 19 Sigma® failures have been confirmed where wire bond connections have separated. Medtronic estimate that approximately 28,000 devices remain implanted worldwide. In the UK 1 failure by this mode has been confirmed to date out of an estimated 1700 devices that remain implanted. The UK failure occurred at implant duration of 36 months with the patient presenting with shortness of breath. Subsequent clinical checking confirmed no pacing output or telemetry.Medtronic have received no reports of serious injuries or deaths due to this problem.Affected Sigma® pacemakers may be identified through accessing the Medtronic website
  • Reason
    (medtronic) failure of interconnecting wires may cause loss of pacing output from atrial and or ventricular ports, premature depletion of battery, intermittent or total loss of telemetry, undersensing, high lead impedance values, loss of rate response, device reset to manufacturer's default settings. (mda/2005/072).
  • Action
    Identify and return to Medtronic all un-implanted devices that are potentially affected (under ‘Download Documents’ below) Identify all patients that have affected pacemakers and where last follow-up was longer than six months, arrange for pacemaker follow-up as soon as possible, giving priority to pacemaker dependant patients. At follow-up confirm that the device is performing as expected. Abnormal device behaviours may include: intermittent or total loss of pacing output in either or both of the atrial/ventricular ports intermittent or total loss of telemetry unanticipated premature battery depletion unexplained increases in lead impedance(s) in unipolar or bipolar mode undersensing loss of rate response function (where applicable and programmed on) power on reset - return to manufacturer’s default settings Advise patients to contact their follow-up clinic immediately if they experience return of symptoms (e.g. syncope / light-headedness or shortness of breath). Consider elective device replacement if any of the above device behaviours are detected, especially for pacemaker dependant patients giving consideration to each patient’s medical history, degree of pacemaker dependency and the relative risks of an invasive procedure. Consider scheduling subsequent pacemaker follow-up at intervals no longer than six months, for all potentially affected pacemakers, to monitor for signs of device degradation. Report all incidents of device failure to the MHRA and Medtronic. Report explants to the National Pacing and ICD Database (see Contacts).


  • Model / Serial
  • Product Description
    Medtronic Sigma® implantable pacemakersModel NumbersSD203 SDR203 SS203 SSR203 SD303 SDR303 SS303 SSR303 SS103 SS106 SDR306 SVDD303
  • Manufacturer


  • Manufacturer Address
    Enquiries to the manufacturer or the National Pacing and ICD Database should be addressed to:David G Dunham BSc PhD Regulatory Affairs Manager - UK & Ireland, Medtronic Ltd, Suite One, Sherbourne House, Croxley Business Centre, Watford WD18 8WWTel: 01923 212 213E-mail: david.dunham@medtronic.comNational Pacing and ICD Database, PO Box 9205, Bridge of Weir, Strathclyde, PA11 3DZTel: 01505 612 829 Fax: 01505 612 829E-mail:
  • Manufacturer Parent Company (2017)
  • Manufacturer comment
    “If our surveillance systems identify a potential performance issue, our personnel promptly evaluate the problem, including, when appropriate, conducting root cause investigations and internal testing to assess whether the product continues to meet specifications and defined performance criteria,” Medtronic told ICIJ in a statement. “In some cases, based on this evaluation, Medtronic may determine that a recall is necessary.” The company said that it communicates with healthcare providers and/or patients and provide recommendations to address such issues. Medtronic noted that these communications can include letters, emails, calls, press releases, physician notifications and social media postings, as well as informing the FDA and other regulators of the actions.
  • Source