MAUDE Adverse Event Report: IRHYTHM TECHNOLOGIES, INC ZEUS SYSTEM; COMPUTER, DIAGNOSTIC, PROGRAMMABLE

Medical Device Problem Codes	Adverse Event Without Identified Device or Use Problem (2993); Inaccurate Information (4051)
Health Effect - Clinical Code	Unspecified Heart Problem (4454)
Date of Event	07/13/2024
Type of Reportable Event	Serious Injury
Additional Manufacturer Narrative
The zio at device was returned to irhythm, and the clinical data was downloaded.A review of the clinical data found that the patient wore the zio at device for 3 days of the 7-day prescribed wear period.Irhythm became aware of the misclassified arrhythmia while preparing the final report and notified the hcp on day 13.The investigation revealed that the algorithm misclassified the arrhythmia and the certified cardiographic technician (cct) subsequently agreed with the algorithm interpretation.The zio at clinical reference manual states in the ¿indications for use¿ section that ¿the reports are provided for review by the intended user to render a diagnosis based on clinical judgment and experience.¿ this event is being reported per 21cfr 803 as a product problem /malfunction.This report does not constitute an admission by irhythm that the product described in this report has any defects or has malfunctioned.These terms are included in form fda 3500a and are fixed terms for selection created by the fda to categorize the type of event solely for the purpose of regulatory reporting.
Event or Problem Description
The patient experienced an arrhythmia that met medical doctor notification (mdn) requirements that was not communicated during the wear period.The investigation revealed that a preliminary ecg interpretation provided to the physician was misclassified.Following the wear period and while compiling the final report, the interpretation was amended.The hcp was notified immediately, and irhythm learned that the patient received a pacemaker due to the initial false positive interpretation.It is unknown whether the pacemaker will be removed.
Additional Manufacturer Narrative
This supplemental report is being submitted in response to the fda notification received on september 26, 2024, concerning missing udi numbers in mdr submissions from october 2023 through december 2024.In response to this issue, irhythm conducted an investigation and identified a system processing error, which has now been resolved.Please see the update in section d4.

• Brand Name: ZEUS SYSTEM
• Common Device Name: COMPUTER, DIAGNOSTIC, PROGRAMMABLE
• Manufacturer (Section D): IRHYTHM TECHNOLOGIES, INC; 699 8th st suite 600; san francisco CA 94103
• Manufacturer (Section G): IRHYTHM TECHNOLOGIES, INC; 6550 katella avenue, suite 200; cypress CA 90630
• Manufacturer Contact: tara mackinnon ; 699 8th st suite 600; san francisco, CA 94103 ; 6094600577
• MDR Report Key: 20006481
• Report Number: 3007208829-2024-00422
• Device Sequence Number: 19927545
• Product Code: DQK
• UDI-Device Identifier: 00850043907046
• UDI-Public: (01)00850043907046
• Combination Product (Y/N): N
• Initial Reporter State: PA
• Initial Reporter Country: US
• PMA/510(K) Number: K222389
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Health Professional,Company Representative
• Initial Reporter Occupation: Other Health Care Professional
• Type of Report: Initial,Followup
• Report Date (Section B): 06/24/2025

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?: No
• Was Device Available for Evaluation?: Yes
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 07/25/2024
• Supplement Date Received by Manufacturer: 06/02/2025
• Initial Report FDA Received Date: 08/20/2024
• Supplement Report FDA Received Date: 06/26/2025
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• 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: Initial
• Patient Sequence Number: 1
• Concomitant Medical Products and Therapy/Usage Dates: ZIO AT/SN: (B)(6).
• Outcome Attributed to Adverse Event: Other
• Patient Age: 84 YR
• Patient Sex: Male