Medical device manufacturer, Boston Scientific, has issued a medical device safety alert concerning its Cardiac Resynchronization Therapy pacemakers (CRT-Ps) and defibrillators (CRT-Ds).

The affected CRT devices are identified as the following:-

• VALITUDE CRT-P [Models: U125 and U128]
• RESONATE CRT-D [Models: G424, G425, G426. G428, G437, G447, G448, G525, G526, G528, G537, G547, G548]
• MOMENTUM CRT-D [Models: G124, G125, G126, G128, G138]
• AUTOGEN CRT-D [Models: G160, G161, G166, G168, G172, G173, G175, G177, G179]
• INOGEN CRT-D [Models: G140, G141, G146, G148]
• VISIONIST CRT-P [Models: U225, U226, U228]
• VIGILANT CRT-D [Models: G224, G225, G228, G237, G247, G248]
• CHARISMA CRT-D [Models: G324, G325, G328, G337, G347, G348]
• DYNAGEN CRT-D [Models: G150, G151, G156, G158]
• ORIGEN CRT-D [Models: G050, G051, G056, G058]

The manufacturer has issued a field action product advisory to physician includes important programming information to prevent an unintended asynchronous biventricular (BiV) pacing behavior when tracking elevated atrial intrinsic rhythms in certain CRT-Ps and CRT-Ds.

According to the manufacturer, repeated detection of the unintended asynchronous BiV pacing behavior may result in the implanted device reverting to a permanent Safety Mode (Safety Core) status thus requiring early replacement. The unintended asynchronous BiV pacing behavior can only occur when an infrequent combination of parameters is programmed, specifically:

• Left Ventricular (LV) Offset programmed to a positive value which exceeds the Atrial Blank after Ventricular Pace (A-Blank after V-Pace) interval; and
• Tracking Preference = ON (nominal).

Until software is available to prevent programming of a susceptible combination of parameters, the advisory's programming recommendations eliminate the risks associated with early device replacement due to the device behavior. CRT devices more commonly programmed to simultaneous BiV pacing (LV Offset = zero) or sequential BiV where LV precedes RV (negative LV Offset value) are not subject to the risks described in the advisory

The manufacturer is actively developing a software update designed to prevent programming of a susceptible combination of parameters.

According to the local supplier, the affected products are distributed in Hong Kong.

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

Posted on 22 December 2017