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	08/15/2026
Type of Reportable Event	Malfunction
Event or Problem Description
A us distributor contacted zoll to report that a patient was experiencing "add gel/replace belt" messages.
Additional Manufacturer Narrative
Device evaluation of electrode belt has been completed.The reported problem (add gel / replace belt messages) has been confirmed.Upon investigation the electrode belt did not pass essential performance testing.The cause for the failure was isolated to a pulse wire broken from the rear 1 wire therapy electrode.The root cause for the open wire was unable to 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: 50841505
• Report Number: 3008642652-2026-09125
• Device Sequence Number: 10060042
• Product Code: MVK
• UDI-Device Identifier: 00855778005012
• UDI-Public: (01)00855778005012(17)280605
• 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