MAUDE Adverse Event Report: ZOLL MANUFACTURING CORPORATION LIFEVEST WCD 4000 SYSTEM; WEARABLE CARDIOVERTER DEFIBRILLATOR

Model Number WCD 4000

Device Problems Over-Sensing (1438); Defibrillation/Stimulation Problem (1573); Inappropriate/Inadequate Shock/Stimulation (1574); Use of Device Problem (1670)

Patient Problems Loss of consciousness (2418); Shock from Patient Lead(s) (3162)

Event Date 10/09/2018

Event Type  Injury  

Manufacturer Narrative

Explanation: there was no death associated with the inappropriate defibrillation event.There is no indication that the patient sustained a serious injury.Device evaluation summary: monitor sn (b)(4) was returned and evaluated at the distributor, in accordance with procedures recommended by zoll manufacturing corporation.The evaluation included review of downloaded software flag files on the day of the event and incoming functional testing.The review of the software flags consisted of an analysis of the downloaded data to identify any fault flags or unusual patterns of software flags.The software flag files did not suggest a device malfunction that would contribute to the inappropriate treatment.During the incoming functional testing, a 1hz simulated normal sinus rhythm signal was applied to the ecg electrodes, followed by a 5hz simulated treatable arrhythmia signal which verified proper performance of the detection algorithm.During the transition to the 5hz signal, the device was confirmed to properly enter into a treatment sequence which includes a verification of the tactile vibration alarm, audio messaging, and siren alarms, as well as a test of the pulse delivery circuitry.The pulse delivery circuitry test verified proper charging of the high voltage capacitors and proper delivery of five full energy 150j biphasic pulses.The functional testing confirmed proper response button functionality, ecg acquisition, detection algorithm performance, and pulse delivery functionality.Device evaluation of electrode belt sn (b)(4) has been completed.Upon investigation the cable connecting ecg a to the front therapy electrode was severed and missing.Additionally, the j500 component was broken off the dn pca.The root cause for the missing cable and the broken component was physical abuse.There is no indication that the electrode belt malfunction caused or contributed to inappropriate treatment event.The investigation into the event concludes that there was no device malfunction.A cause and effect analysis was conducted using all of the available information which includes the incident report, device evaluation, software flag files, and ecg strips.The primary cause of the inappropriate shock was improper response button use prior to shock delivery.The response buttons were pressed earlier in the detection sequence but not immediately prior to shock delivery, and also after shock delivery.The response buttons functioned appropriately.The ecg analysis, conducted by trained ecg technicians, identified the primary cause of the false detection was multiple counting of low-amplitude cardiac signal.Inappropriate defibrillations are an anticipated risk associated with the use of the lifevest.Patients are instructed through alarms, voice messages, ifu, and training to press the response buttons to prevent an inappropriate defibrillation.(b)(4).A summary of the safety and effectiveness data (ssed), including the inappropriate defibrillation safety objective supporting fda's approval of the lifevest, can be found at .The lifevest detection algorithm complies with iec 60601-2-4 performance requirements for sensitivity and specificity.

Event Description

A us distributor contacted zoll to report that a patient experienced an inappropriate defibrillation event consisting of one shock.The patient reportedly lost consciousness during the event.It was also reported that the patient's wife was pressing the response buttons.Multiple counting of low-amplitude cardiac signal contributed to the false detection.The response buttons were pressed earlier in the detection sequence, but not immediately prior to shock delivery.The response buttons were also pressed after the treatment was delivered.The response buttons functioned appropriately.Ems was called and the patient was transported to the hospital after the event.The patient's doctors have ended use of the lifevest.There was no death or serious injury associated with the inappropriate defibrillation event.

• Brand Name: LIFEVEST WCD 4000 SYSTEM
• Type of Device: WEARABLE CARDIOVERTER DEFIBRILLATOR
• Manufacturer (Section D): ZOLL MANUFACTURING CORPORATION; 121 gamma drive; pittsburgh PA 15238 3495
• Manufacturer (Section G): ZOLL MANUFACTURING CORPORATION; 121 gamma drive; pittsburgh PA 15238 3495
• Manufacturer Contact: mary ward ; 121 gamma drive; pittsburgh, PA 15238-3495 ; 4129683333
• MDR Report Key: 8056063
• MDR Text Key: 126701020
• Report Number: 3008642652-2018-09521
• Device Sequence Number: 0
• Product Code: MVK
• PMA/PMN Number: P010030
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: distributor
• Type of Report: Initial
• Report Date: 11/07/2018

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
• Device Operator: Lay User/Patient
• Device Model Number: WCD 4000
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 11/01/2018
• Initial Date Manufacturer Received: 10/10/2018
• Initial Date FDA Received: 11/09/2018
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 06/17/2016
• Is the Device Single Use?: No
• Is This a Reprocessed and Reused Single-Use Device?: No
• Type of Device Usage: Reuse
• Patient Sequence Number: 1
• Patient Outcome(s): Hospitalization; Other
• Patient Age: 54 YR