The US Food and Drug Administration has raised an alert for patients to the Class I recall of certain Medtronic Kappa and Sigma pacemakers. These devices may fail due to a separation of wires that connect the electronic circuit to other pacemaker components, such as the battery.

Patients with malfunctioning pacemakers may experience a return of symptoms associated with abnormal heart rate, such as fainting or lightheadedness. In rare cases, pacemaker-dependent patients may experience serious injury or even death.

There are more than 1.7 million Kappa or Sigma pacemakers implanted in patients throughout the world. Of those, only about 21,000 pacemakers are affected by this recall, most of which have been implanted in patients for five years or longer.

Medtronic issued a letter to physicians alerting them to this problem on May 18. The company communicated with patients via letter on May 27.

The affected pacemakers are Kappa Series 600/700/900 and Sigma Series 100/200/300. Patients with these models of Kappa and Sigma pacemakers should determine if their pacemaker is part of this recall by contacting Medtronic at 800-505-4636 or going to their web site at http://www.KappaSigmaSNList.medtronic.com.

Patients who have these recalled pacemakers and those who are unsure if their pacemakers are affected should follow up with their primary care physician or cardiologist.

Through standard medical device reporting requirements, the FDA became aware of possible problems and worked with the company to address them. The FDA classified this voluntary recall as Class-I, indicating reasonable probability that the use of the device will cause serious adverse health consequences or death.