The Australia Therapeutic Goods Administration (TGA) posted a medical device safety alert concerning implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy defibrillators (CRT-Ds) programmed with Merlin Programmer Software Version 17.2.2 rev. 0, manufactured by St. Jude Medical.

According to the manufacturer's information, the affected models include Current VR, Current Accel VR RF, Current DR, Current Accel DR RF, Promote, Promote Accel RF, Promote Quadra, AnalyST Accel VR RF, AnalyST Accel DR RF, Fortify ST VR, Fortify ST DR, Fortify Assura VR, Fortify Assura DR, Ellipse VR, Ellipse DR, Unify, Unify Quadra, Unify Assura CRT-D, Quadra Assura CRT-D, and Quadra Assura MP CRT-D.

When using the 17.2.2 software and any parameter that is programmed as part of a single VF detection zone configuration, the sinus redetection value will be inappropriately set to zero milliseconds. As a result, any intrinsic activity following the first shock will be considered a "sinus rate" and the device will diagnose "return to sinus". Therefore, if the arrhythmia was not terminated by the initial high voltage therapy, the ongoing arrhythmia would be considered a new episode causing the next high voltage therapy to also be delivered at the first programmed energy level.

The manufacturer advises users of the followings:

• Review St Jude Medical ICD/CRT-D patient records for patients with affected devices implanted or seen in clinic starting in September 2013 and programmed to a single VF detection zone with the 17.2.2 software. For patients identified during this review, users should schedule an immediate follow-up visit.
• For patient devices programmed as described above with 17.2.2 software, St. Jude Medical will arrange installation of a new software version 17.2.3 to correct this issue.
• If a patient is seen before the 17.2.3 software is installed, then program the device to a two or three zone configuration, even if one of the zones is strictly a monitor zone. This will resolve the issue when using a programmer with 17.2.2 software.

According to the local supplier, products with affected software version 17.2.2 were not distributed in Hong Kong.

For details, please refer to TGA website
http://www.tga.gov.au/SARA/arn-detail.aspx?k=RC-2014-RN-00034-1

If you are in possession of the product, please contact your supplier for necessary actions.

Posted on 28 January 2014