Merlin Patient Care System (PCS) Programmer and Merlin 2 PCS Programmer When Used with Gallant, Neutrino NxT, or Entrant Devices

Background

Publication Date: March 23, 2022

Abbott has detected a software anomaly in the Merlin^TM and Merlin^TM 2 Patient Care System (PCS) programmers that have software versions supporting Gallant^TM, Neutrino^TM NxT, and EntrantTM devices. The issue is specific to using the Decrement Test Method (either voltage or pulse width decrement threshold testing) on the programmer to perform a pacing capture threshold test on a Gallant, Neutrino NxT, or Entrant device. When the user lets go of the "Hold to Test" button on the programmer screen within a narrow time window occurring approximately 2.5 seconds after test initiation (which roughly correlates to the first decrement), the Decrement Test will continue running until an output of 0.25V is reached or telemetry communication is broken. There have been 21 complaints for this issue out of approximately 38,000 implanted devices worldwide.

There have been no reports of serious harm to patients resulting from this issue. However, transient asystole in a pacemaker-dependent patient could occur during the Decrement Test when pacing below the patient's capture threshold.

Updates

Abbott has developed a programmer software update, which corrects this issue. The timing of this update varies by country and geographic region. In the U.S., the programmers will be updated by Abbott representatives starting in March 2022.

Abbott Recommendations

Abbott recommends the following if a patient with a Gallant, Neutrino NxT, or Entrant device requires a full device interrogation before the programmer software has been updated:

• Consider placing the patient in the supine position if the patient is pacemaker-dependent.
• Start the Decrement Test at a significantly higher value than the anticipated capture threshold. 
• During the Decrement Test to determine the capture threshold, do not release the "Hold to Test" button before it has completed the first decrement step which takes approximately 2-3 seconds.
• If the Decrement Test continues after the "Hold to Test" button is released, break the telemetry communication to restore the permanent programmed parameters. Telemetry can be broken by moving the inductive wand, disconnecting the Bluetooth dongle, or powering down the programmer.

HRS Recommendations

HRS strongly encourages its members to read the U.S. Abbott Safety notification or International Abbott Safety notification.

Reporting Adverse Reactions or Quality Problems 

Adverse reactions or quality problems experienced with the use of this product should be reported to Abbott and to the FDA MedWatch Safety Information and Adverse Event Reporting Program either online, by regular mail, or by fax.

• Complete and submit a report online by clicking on “Report a Problem.”
• Call 1-800-332-1088 to request a reporting form, or download the form here. Forms may also be mailed or faxed.

For additional questions, contact your local Abbott Representative or Abbott Technical Services at 1-800-722-3774.