Device: All models of RF enabled St. Jude Medical Implantable Cardioverter Defibrillators (Ellipse Fortify Assura, Unify Assura, and Quadra Assura) and Pacemakers (Assurity and Allure) when used with Merlin@home RF Remote Monitor Model EX1150.

Advisory Grade TGA: Hazard Alert

ANZDACC Advisory Grade: Elective/Routine

Number in Australia: Not known or identifiable

Risk: In addition to the advisory notice published  22nd December 2014 another soft ware anomaly has been discovered in the Merlin@home RF Remote Monitor Model EX1150. The new software anomaly have revealed a potential scenario caused by a noisy wireless connection that will revert the device to back-up operation as a precautionary measure to ensure basic operation.

Description: St Jude Medical has advised there is a potential for the aforementioned devices to be placed in a  backup mode, the nominal operational settings  for defibrillators will be VVI pacing mode, 67 ppm, 5.0 V/0.6 ms with bipolar pacing output and defibrillation settings of a VF detection rate of 146 bpm and 36 J high voltage therapy. In back up mode inappropriate defibrillation may ensue. The likelihood of an RF-enabled ICD to be potentially impacted by this anomaly is 0.3%.

For the pacemakers, output settings of VVI pacing mode, 67 ppm, 5.0 V/0.6 ms with unipolar pacing. The likelihood of an RF-enabled pacemaker to be potentially impacted by this anomaly is 0.07%.

In back up mode the ICD will deliver a vibratory alert and the pacemakers an audible alert.

Inductive remote monitored or non remote monitored devices are not affected.

Presentation: Patients device will alert via an audible beeping tone or vibration and will receive an alert transmission via Merlin@Home transmitter.

Advice: No change to device follow up schedule (remote or in clinic) is advised until the issue presents. Patients that are affected by this issue require immediate in person follow up to allow for software rebuild and device reprogramming.

The Merlin@home transmitter software has been modified to prevent this issue from occurring. The process of “uploading” this new software to patient transmitters will begin shortly. This update will be performed automatically over the telephone, broadband, or cellular connection without requiring any action from the patient. No changes to your patient’s remote or in-clinic follow up schedules are required.