MAUDE Adverse Event Report: BOSTON SCIENTIFIC CORPORATION DYNAGEN? X4 CRT-D; CARDIAC RESYNCHRONIZATION THERAPY DEFIBRILLATOR

Model Number	G156
Medical Device Problem Codes	Signal Artifact/Noise (1036); Failure to Capture (1081); High impedance (1291); Over-Sensing (1438); Pacing Problem (1439); Inappropriate/Inadequate Shock/Stimulation (1574); Failure to Read Input Signal (1581); Low impedance (2285)
Health Effect - Clinical Codes	Shock from Patient Lead(s) (3162); Asystole (4442)
Date of Event	08/25/2025
Type of Reportable Event	Serious Injury
Additional Manufacturer Narrative
If pertinent information is provided in the future, a supplemental report will be submitted.
Event or Problem Description
It was reported that this cardiac resynchronization therapy defibrillator (crt-d) exhibited dramatic oversensing on the right ventricular (rv) channel.Oversensing of noise resulted in pacing inhibition greater than five seconds.Oversensing resulted in inappropriate anti-tachycardia pacing and a single inappropriate shock to be delivered.Technical services (ts) advised amplitudes are low and loss of capture was exhibited on the presenting electrogram.In addition, ts found intermittent high out of range right atrial (ra) pacing impedance measurements.However, ra pacing impedance measurements are now gradually decreasing but remain within range.A gradual rise in rv shock impedance measurements was also observed.However, shock impedance measurements remained within normal limits at this time.A temporary pacemaker was used.This crt-d was subsequently explanted due to normal battery depletion.This crt-d has not been returned at this time.No additional adverse patient effects were reported.
Additional Manufacturer Narrative
This correction report is being submitted due to changes in the h11 additional mfr narrative field.This product has not been returned to boston scientific, and as a result, laboratory analysis could not be conducted.The associated investigation determined that this device exhibited intermittent changes in impedance measurements with no conclusive evidence of a product performance issue or inadequate lead-to-device connection; please refer to the b5 describe event or problem field for more information regarding the specific circumstances of this event.Engineering analysis and testing of returned products has determined that repeated, small movements of the lead terminal ring along with variances in the connection contact force and surface roughness can impact the connection between the spring contact and the lead ring, resulting in intermittent changes in impedance measurement.A review of the device history record (dhr) was performed.The review of the dhr identified that there were no process related non-conformances, scrap, or rework performed during the production that could explain the event.The reviews ensure each device meets specification prior to release for use.A risk review was completed and confirmed that the event of oversensing was defined in the risk documentation.This event type has been accounted for during product risk analysis to support acceptable risk benefit for the product.Review of labeling determined that the complaint situation was listed in the manual.There was no indication in the complaint that the product was not used in accordance to labeling.The manual was unlikely to be the cause of the reported complaint; translation, wording, or graphics does not require further review.If pertinent information is provided in the future, a supplemental report will be submitted.
Event or Problem Description
It was reported that this cardiac resynchronization therapy defibrillator (crt-d) exhibited dramatic oversensing on the right ventricular (rv) channel.Oversensing of noise resulted in pacing inhibition greater than five seconds.Oversensing resulted in inappropriate anti-tachycardia pacing and a single inappropriate shock to be delivered.Technical services (ts) advised amplitudes are low and loss of capture was exhibited on the presenting electrogram.In addition, ts found intermittent high out of range right atrial (ra) pacing impedance measurements.However, ra pacing impedance measurements are now gradually decreasing but remain within range.A gradual rise in rv shock impedance measurements was also observed.However, shock impedance measurements remained within normal limits at this time.A temporary pacemaker was used.This crt-d was subsequently explanted due to normal battery depletion.This crt-d has not been returned at this time.No additional adverse patient effects were reported.
Additional Manufacturer Narrative
This product has not been returned to boston scientific, and as a result, laboratory analysis could not be conducted.The associated investigation determined that this device exhibited intermittent changes in impedance measurements with no conclusive evidence of a product performance issue or inadequate lead-to-device connection; please refer to the b5 describe event or problem field for more information regarding the specific circumstances of this event.Engineering analysis and testing of returned products has determined that repeated, small movements of the lead terminal ring along with variances in the connection contact force and surface roughness can impact the connection between the spring contact and the lead ring, resulting in intermittent changes in impedance measurement.A review of the device history record (dhr) was performed.The review of the dhr identified that there were no process related non-conformances, scrap, or rework performed during the production that could explain the event.The reviews ensure each device meets specification prior to release for use.Review of the instructions for use (ifu) confirmed there was relevant content and sufficient guidance with respect to the circumstances described within this complaint.No updates are required to the ifu as a result of this event.A risk review was completed and confirmed that the event of caused traced to device design was defined in the risk documentation.This event type has been accounted for during product risk analysis to support acceptable risk benefit for the product.If pertinent information is provided in the future, a supplemental report will be submitted.
Event or Problem Description
It was reported that this cardiac resynchronization therapy defibrillator (crt-d) exhibited dramatic oversensing on the right ventricular (rv) channel.Oversensing of noise resulted in pacing inhibition greater than five seconds.Oversensing resulted in inappropriate anti-tachycardia pacing and a single inappropriate shock to be delivered.Technical services (ts) advised amplitudes are low and loss of capture was exhibited on the presenting electrogram.In addition, ts found intermittent high out of range right atrial (ra) pacing impedance measurements.However, ra pacing impedance measurements are now gradually decreasing but remain within range.A gradual rise in rv shock impedance measurements was also observed.However, shock impedance measurements remained within normal limits at this time.A temporary pacemaker was used.This crt-d was subsequently explanted due to normal battery depletion.This crt-d has not been returned at this time.No additional adverse patient effects were reported.

• Brand Name: DYNAGEN? X4 CRT-D
• Common Device Name: 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 ; EI
• Manufacturer Contact: timothy degroot ; 4100 hamline avenue north; saint paul, MN 55112 ; 6515826168
• MDR Report Key: 23126472
• Report Number: 2124215-2025-66994
• Device Sequence Number: 17955689
• Product Code: NIK
• UDI-Device Identifier: 00802526534669
• UDI-Public: (01)00802526534669(17)180222
• Combination Product (Y/N): N
• Initial Reporter State: MO
• Initial Reporter Country: US
• PMA/510(K) Number: P010012
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2016
• Device Explanted Year: 2025
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Health Professional,Company Representative
• Initial Reporter Occupation: Physician
• Type of Report: Initial,Followup,Followup
• Report Date (Section B): 03/04/2026

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: Lay User/Patient
• Device Expiration Date: 02/22/2018
• Device Model Number: G156
• Device Catalogue Number: G156
• Device Lot Number: 372533
• 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: 08/27/2025
• Supplement Date Received by Manufacturer: 03/03/2026; 03/03/2026
• Initial Report FDA Received Date: 09/23/2025
• Supplement Report FDA Received Date: 03/03/2026; 03/04/2026
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Date Device Manufactured: 10/19/2016
• 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
• Outcome Attributed to Adverse Event: Required Intervention
• Patient Age: 82 YR
• Patient Sex: Male