MAUDE Adverse Event Report: BOSTON SCIENTIFIC CORPORATION MOMENTUM? X4 CRT-D; Implantable Cardiac Resynchronization Therapy Defibrillator

Model Number	G138
Medical Device Problem Codes	Over-Sensing (1438); Pacing Problem (1439)
Health Effect - Clinical Codes	Bradycardia (1751); No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	08/01/2026
Type of Reportable Event	Malfunction
Event or Problem Description
It was reported that this cardiac resynchronization therapy defibrillator (crt-d) inhibited pacing.Additionally, farfield r wave oversensing was noted.Technical services (ts) was consulted to review an atrial tachy response (atr) episode and found that atrial pacing was inhibited due to atrial flutter response (afr).Ts found regular farfield r wave oversensing in events and determined it was less persistent when a mode switch occurred but was still present.Ts offered next steps to establish a root cause for the pacing inhibition.No adverse patient effects were reported.This crt-d remains in service.
Additional Manufacturer Narrative
This product investigation is still in progress.This report will be updated when product investigation is complete.If pertinent information is provided in the future, a supplemental report will be submitted.

• Brand Name: MOMENTUM? X4 CRT-D
• Common Device Name: Implantable Cardiac Resynchronization Therapy Defibrillator
• Manufacturer (Section D): BOSTON SCIENTIFIC CORPORATION; 4100 hamline avenue north; saint paul MN 55112
• Manufacturer (Section G): Boston Scientific Corporation; cashel road; clonmel E91 T 862; EI E91 T862
• Manufacturer Contact: mark mischke ; 4100 hamline avenue north; saint paul, MN 55112 ; +1(612)875-7234
• MDR Report Key: 50839789
• Report Number: 2124215-2026-50156
• Device Sequence Number: 10262747
• Product Code: NIK
• UDI-Device Identifier: 00802526589188
• UDI-Public: (01)00802526589188(17)260513
• Combination Product (Y/N): N
• Initial Reporter State: WA
• Initial Reporter Country: US
• PMA/510(K) Number: P010012
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2024
• Reporter Type: Manufacturer
• Report Source: Health Professional
• Initial Reporter Occupation: Other Health Care Professional
• Type of Report: Initial,Followup
• Report Date (Section B): 09/24/2026

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Operator of Device: Lay User/Patient
• Device Expiration Date: 05/13/2026
• Device Model Number: G138
• Device Catalogue Number: G138
• Device Lot Number: 395926
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 09/08/2026
• Supplement Date Received by Manufacturer: 09/21/2026
• Initial Report FDA Received Date: 09/21/2026
• Supplement Report FDA Received Date: 09/24/2026
• Date Device Manufactured: 05/23/2024
• 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
• Patient Age: 61 YR
• Patient Sex: Male