MAUDE Adverse Event Report: ST. JUDE MEDICAL, INC.(CRM-SYLMAR) ZEPHYR XL SR; PULSE GENERATOR, PERMANENT, IMPLANTABLE

Model Number	5626
Medical Device Problem Code	Unexpected Mode Switch (4076)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	08/14/2025
Type of Reportable Event	Serious Injury
Event or Problem Description
It was reported that the asymptomatic patient presented for a follow-up in clinic.Upon interrogation, it was noted that the pacemaker exhibited a backup vvi mode.The pacemaker was explanted and replaced.The patient was in stable condition.
Additional Manufacturer Narrative
The reported event of unexpected mode switch was confirmed.The device was received in backup mode for analysis.The product code was reloaded to enable further testing.Post-reload analysis, including telemetry and pacing output, indicated that the pacer exhibited normal device characteristics.Analysis of the device image revealed that the backup mode was triggered by an nmi (non-maskable interrupt).Code corruption led to a false low battery reset which triggered the nmi.The reset condition could not be reproduced, and the root cause of the code corruption remains unknown.A longevity assessment was performed, and battery depletion was found to be normal based on device usage.

• Brand Name: ZEPHYR XL SR
• Common Device Name: PULSE GENERATOR, PERMANENT, IMPLANTABLE
• Manufacturer (Section D): ST. JUDE MEDICAL, INC.(CRM-SYLMAR); 15900 valley view court; sylmar CA 91342
• Manufacturer (Section G): ST. JUDE MEDICAL, INC.(CRM-SYLMAR); 15900 valley view court; sylmar CA 91342
• Manufacturer Contact: navpreet singh ; 15900 valley view court; sylmar, CA 91342
• MDR Report Key: 22935578
• Report Number: 2017865-2025-99084
• Device Sequence Number: 9920011
• Product Code: NVZ
• UDI-Device Identifier: 05414734501712
• UDI-Public: (01)05414734501712(10)2837734(17)110228
• Combination Product (Y/N): N
• Initial Reporter State: OH
• Initial Reporter Country: US
• PMA/510(K) Number: P880086
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2010
• Device Explanted Year: 2025
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Health Professional,User Facility,Company Representative
• Initial Reporter Occupation: Physician
• Type of Report: Initial,Followup
• Report Date (Section B): 11/06/2025

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Operator of Device: Health Professional
• Device Expiration Date: 02/28/2011
• Device Model Number: 5626
• Device Lot Number: 2837734
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 08/21/2025
• Is the Reporter a Health Professional?: Yes
• Was the Report Sent to FDA?: No
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 08/14/2025
• Supplement Date Received by Manufacturer: 11/05/2025
• Initial Report FDA Received Date: 09/02/2025
• Supplement Report FDA Received Date: 11/05/2025
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Date Device Manufactured: 08/05/2009
• Is the Device Labeled for Single Use? (Y/N): Yes
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Usage of Device: Initial
• Patient Sequence Number: 1
• Concomitant Medical Products and Therapy/Usage Dates: RIGHT VENTRICULAR LEAD.
• Outcome Attributed to Adverse Event: Required Intervention
• Patient Sex: Male