MAUDE Adverse Event Report: IRHYTHM TECHNOLOGIES, INC ZIO XT; RECORDER, MAGNETIC TAPE, MEDICAL

Medical Device Problem Code	Patient-Device Incompatibility (2682)
Health Effect - Clinical Code	Hypersensitivity/Allergic reaction (1907)
Date of Event	09/26/2024
Type of Reportable Event	Serious Injury
Event or Problem Description
The patient presented to the healthcare provider with signs of an allergic reaction, reportedly caused by the zio xt.The patient stated that hives developed within 48 hours after the zio xt application.Despite this reaction, the patient continued to wear the zio xt for the rest of the prescribed period.The patient was prescribed benadryl and prednisone for treatment.
Additional Manufacturer Narrative
A review of the complaint revealed that the patient wore the xt for the 14-day prescribed wear period.It is unknown if the patient has a history of reactions to medical adhesives or sensitive skin.The cause of the reported event cannot be determined.However, skin irritation is a known inherent risk of the device.The device manual warnings section read as follows: do not use the zio xt patch on patients with known allergic reaction to adhesives or hydrogels or with a family history of adhesive skin allergies.Patient may experience skin irritation.If skin irritation such as severe redness, itching or allergic symptoms develop, remove the zio xt patch from the patient¿s chest.This event is being reported per 21cfr803 as a serious injury.This report does not constitute an admission by rhythm 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.
Additional Manufacturer Narrative
This supplemental mdr is being submitted as a part of retrospective review from january 2021 till august 2025.A capa (2024-0036) was initiated on 29th september 2024 to implement corrective actions.Device performance and/or risk profile are not impacted.

• Brand Name: ZIO XT
• Common Device Name: RECORDER, MAGNETIC TAPE, MEDICAL
• 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: 22800799
• Report Number: 3007208829-2025-00018
• Device Sequence Number: 8846371
• Product Code: DSH
• UDI-Device Identifier: 00869770000203
• UDI-Public: (01)00869770000203(17)250212
• Combination Product (Y/N): N
• PMA/510(K) Number: K121319
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Consumer
• Initial Reporter Occupation: Non-Healthcare Professional
• Type of Report: Initial,Followup
• Report Date (Section B): 08/28/2025

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
• Operator of Device: Lay User/Patient
• Device Expiration Date: 02/12/2025
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 10/18/2024
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 10/18/2024
• Supplement Date Received by Manufacturer: 08/26/2025
• Initial Report FDA Received Date: 08/13/2025
• Supplement Report FDA Received Date: 08/28/2025
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Date Device Manufactured: 08/16/2024
• 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: Required Intervention
• Patient Age: 50 YR
• Patient Sex: Female