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

Model Number	G447
Medical Device Problem Code	Defibrillation/Stimulation Problem (1573)
Health Effect - Clinical Codes	Ventricular Fibrillation (2130); Syncope/Fainting (4411)
Date of Event	09/01/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
It was reported that this cardiac resynchronization therapy defibrillator (crt-d) delivered anti-tachycardia pacing (atp) for ventricular tachycardia; however, the atp accelerated the rhythm from ventricular tachycardia to ventricular fibrillation.Additionally, the patient experienced syncope during the event.Technical services (ts) was consulted and confirmed the device was operating as programmed, and a max voltage shock converted the accelerated arrythmia.Ts noted that the patient did not feel the shock due to syncope.No additional 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: RESONATE? 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: 50774639
• Report Number: 2124215-2026-49146
• Device Sequence Number: 21261905
• Product Code: NIK
• UDI-Device Identifier: 00802526589539
• UDI-Public: (01)00802526589539(17)230219
• Combination Product (Y/N): N
• Initial Reporter State: CA
• Initial Reporter Country: US
• PMA/510(K) Number: P010012
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2021
• Reporter Type: Manufacturer
• Report Source: Health Professional
• Initial Reporter Occupation: Physician
• Type of Report: Initial
• Report Date (Section B): 09/15/2026

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: 02/19/2023
• Device Model Number: G447
• Device Catalogue Number: G447
• Device Lot Number: 255032
• 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: 09/02/2026
• Initial Report FDA Received Date: 09/15/2026
• Date Device Manufactured: 03/04/2021
• 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: Life Threatening
• Patient Age: 72 YR
• Patient Sex: Unknown