The St. Paul, Minn.-based medical device company sent the letter Jan. 29 after reviewing incident reports on "incident reports on specific older generation pacemaker models," alerting doctors of the possible problem with its Affinity, Entity, Integrity, Identity, Sustain, Frontier, Victory and Zephyr pacemaker models when exposed to electrocautery.
"When devices from these pacemaker families are exposed to electrocautery (as well as the Peak PlasmaBlade blade), they may exhibit a temporary change in function that could persist for 30 seconds or longer after the electrocautery exposure has been terminated," according to the letter. "The duration of the effect depends on several factors including the battery voltage of the device, the energy of the electrocautery output, and the distance from the electrocautery source to the implanted system. The most clinically significant observation has been loss of capture due to a transient reduction in the pacing output voltage. Placing a magnet over the device or programming to an asynchronous pacing mode will not prevent this temporary reduction in pacing output."
The problem does not appear to occur with newer St. Jude pacemakers, including the Accent and Anthem models, or with its implantable cardiac defibrillators, according to the letter.
"If pacemaker dependency is identified, either do not use electrocautery or employ appropriate precautions to ensure that the heart rate will be supported in the presence of electrocautery. Consideration of placing a temporary transvenous pacemaker is appropriate," St. Jude said in the letter.