MAUDE Adverse Event Report: ZOLL Manufacturing Corporation LifeVest WCD 4000 System; Wearable Cardioverter Defibrillator

Model Number	LifeVest WCD 4000 System
Medical Device Problem Code	Structural Problem (2506)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	09/02/2026
Type of Reportable Event	Malfunction
Event or Problem Description
A us distributor reported that a patient was experiencing check therapy electrode messages.
Additional Manufacturer Narrative
Device evaluation of electrode belt has been completed.The reported problem (check therapy electrode messages) has been confirmed.Upon investigation the electrode belt did not pass a therapy electrode recognition test.The cause for the failure was isolated to an open pulse wire in the cable connecting ecg "a" and the front therapy electrode.The root cause for the open wire could not be positively identified.There were no adverse events associated with the damaged belt.

• Brand Name: LifeVest WCD 4000 System
• Common Device Name: Wearable Cardioverter Defibrillator
• Manufacturer (Section D): ZOLL Manufacturing Corporation; 121 gamma drive; pittsburgh PA 15238
• Manufacturer (Section G): ZOLL Manufacturing Corporation; 121 gamma drive; pittsburgh PA 15238
• Manufacturer Contact: zoll mfg corporation ; 121 gamma drive; pittsburgh, PA 15238
• MDR Report Key: 50843218
• Report Number: 3008642652-2026-09143
• Device Sequence Number: 16018215
• Product Code: MVK
• UDI-Device Identifier: 00855778005012
• UDI-Public: (01)00855778005012(17)270604
• Combination Product (Y/N): N
• Initial Reporter State: PA
• Initial Reporter Country: US
• PMA/510(K) Number: P010030
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Reporter Type: Manufacturer
• Report Source: Distributor
• Type of Report: Initial
• Report Date (Section B): 09/21/2026

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 Model Number: LifeVest WCD 4000 System
• Is the Reporter a Health Professional?: No
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 09/21/2026
• Initial Report FDA Received Date: 09/21/2026
• Is the Device Labeled for Single Use? (Y/N): No
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Usage of Device: Reuse
• Patient Sequence Number: 1
• Patient Sex: Unknown