Medtronic Pacemaker Defects Reported Among Kappa and Sigma Devices

Approximately 37,000 Medtronic Kappa and Sigma pacemakers could contain a wiring defect, according to an advisory letter Medtronic sent to doctors this month. The defect could cause the pacemaker to fail and potentially result in serious injury or death.

At least two fatalities have already been reported that may have been caused by the Medtronic pacemaker defects, which can result in the separation of the wiring between the circuit board and other components. This could cause a loss of rate response, battery depletion, loss of telemetry or no output. Patients who are experiencing problems with the faulty pacemakers may show signs of fanting or lightheadedness.

Out of nearly 1.7 million Kappa and Sigma pacemakers implanted in patients since 1997, Medtronic estimates that less than 2% of the devices contain the wiring defect. The pacemakers were primarily manufactured between November 2000 and November 2002, and many are already approaching the normal elective replacement time.

Doctors were notified that approximately 15,200 patients implanted with Medtronic Kappa pacemakers and 6,100 patients with Medtronic Sigma pacemakers should be monitored for potential device failures. In addition, another 15,600 patients with Sigma devices that were included in a 2005 advisory involving wire separations caused by a cleaning solvent used during the manufacturing process, may also impacted by this wiring defect.

Despite the potential pacemaker problems, Medtronic has not recommended that physicians consider device replacement unless a patient is pacemaker dependent. If the device is not already at the elective replacement time, Medtronic is offerinig a supplemental device warranty for those patients.

For non-pacemaker dependent patients, physicians have been advised to continue routine follow up and to instruct patients to seek immediate medical attention if they experience symptoms like fainting or lightheadedness.

Medtronic currently faces a number of lawsuits regarding an October 2007 Sprint Fidelis defibrillator lead recall, which involved a faulty electrical wire that connects the defibrillator to the heart. The defective lead was removed from the market because it was found to be prone to fracturing or breaking, which could result in a massive electrical shock or cause the defibrillator to not work when it is needed.

The Heart Rhythm Society has suggested that the FDA and device manufacturers should cease use of the word “recall” in association with implanted heart devices, instead calling the actions advisories or safety noticies. The advocacy group fears that many patients automatically assume that they must undergo surgery to have the defective device removed in its entirety if a recall is issued. However, in many cases, the small chance of a device failure is not great enough to warrant the risk of undergoing a replacement surgery.