Pacemaker Magnet Rate, Battery Voltage and Elective Replacement Indicator (ERI) Indication

Magnet Rate Is Not Latched at ERI in the Affinity™, Integrity™, Identity™, Frontier™, Sustain™, VerityVictory™ and Zephyr™ Pacemaker Families

On 31 Jan 2017 Abbott (formerly St. Jude Medical) published information via email for customers regarding patients implanted with our company’s older generation pacemakers, such as Affinity, Integrity, Identity, Frontier, Sustain, Verity, Victory, and Zephyr. This information is to ensure physicians are well-informed that the magnet rate on these devices is designed to show the user the relative condition of the battery voltage at the time of the last 23 hour measurement.

Magnet rate is considered a qualitative measurement and when transtelephonic monitoring (TTM) is used, magnet rate is considered a primary indicator for device replacement. However it is not necessarily a quantitative indicator of the battery condition.

For the product families listed above, the magnet rate is not latched* at Elective Replacement Indicator (ERI) and will only show an ERI magnet rate if the last daily measured battery voltage was ≤ 2.50 volts. The battery condition (and subsequent magnet rate) can fluctuate as described in the Technical Insight document linked below. We are informing physicians to be aware that once ERI has been triggered in the specific devices highlighted here, the ERI magnet rate is not latched and in some cases may recover to a value above the ERI magnet rate. It is important for physicians to interrogate patient devices in-clinic using the programmer as devices approach elective replacement in order to better assess the remaining battery longevity of these specific pacemaker devices.

The newer generation of Abbott pacemakers, such as Accent™, Anthem™, Endurity™, Assurity™, Allure™ and subsequent models, use a battery with different characteristics and the ERI magnet rate is latched once the device reaches elective replacement voltage.

For further information on the non-latching pacemaker behavior, please read the technical information document.

PDF Technical Information: Magnet Rate, Battery Voltage and ERI Indications (74kb)
*A non-latching magnet mode is a design feature where the battery temporarily drops below the ERI voltage threshold and then recovers. Programmer interrogation will show demand rate ECG at ERI, but the magnet rate will not show ERI until the battery voltage again drops below ERI.

January 2017