MAUDE Adverse Event Report: CARDIONET/ BIOTELEMETRY TECHNOLOGIES MOBILE CONTINUOUS OUTPATIENT TELEMETRY (MCOT); CARDIONET SENSOR

Catalog Number 100-0028-02

Device Problem Improper Chemical Reaction (2952)

Patient Problems Erythema (1840); Itching Sensation (1943); Pain (1994); Skin Irritation (2076)

Event Date 04/24/2017

Event Type  Injury  

Event Description

The reported device is a 3-lead cardiac sensor (mcot) distributed by (b)(4), it was prescribed to be worn for 2 weeks continuously, except for breaks for bathing.The electrode leads are colored red, white and black.After wearing the sensors for about 2 days, the pt noticed adverse symptoms and wondered whether the device might be defective.The following d.C.Voltages were observed on the following leads when the device was powered (but not connected to electrode patches); black to white: 562 mv d.C (white lead positive) red to white: 565 mv d.C.(white lead positive) in theory, there should have been no measurable voltage present.The following symptoms were observed.After about 24 hours of wear, a bright red wheal appeared under the black lead electrode and extended about 3 cm out from the electrode adhesive pad.Veins in the affected area appeared darker and more prominent than elsewhere.The site was painful and itched for about 2 weeks.Basic chemistry tells us that when a dc voltage is applied to a saline solution, hydrogen gas, chlorine gas and sodium hydroxide (lye) are produced; 2nacl + 2h2 o--> 2naoh + h2 + ci2.In this case, the saline solution was the pt's perspiration, and the dc voltage was applied by the monitor as indicated above.As the pt perspired, a path of saline solution (e.G., perspiration) was established between 2 active electrodes and electrolysis began, causing the release of hydrogen and chlorine gas and the formation of sodium hydroxide.The generation of sodium hydroxide would be expected to cause a severe skin irritation.Please note the electrolysis would not be limited to the surface of the skin, so that the sodium hydroxide appearing subdermally could continue irritation after removal of the electrode patch and after bathing.For a report similar symptoms, please refer to mdr report #mw5029417.In this case, the defect in the sensor was apparently not discovered.After about 10 hours of wear, the pt observed a worsening of cardiac symptoms and malaise and improvement of symptoms when the monitor was removed or powered off.This observation was repeated about 10 times over the course of 2 weeks.In the science of electrical muscle stimulation (ems), it has long been understood that the application of an electrical stimulation to a muscle can cause it to flex.In clinical applications (including tens and nmes) brief electrical pulses are applied to block pain signals or increase muscle tone.It follows that a constant current applied over the course of several hours would be expected to cause the affected muscles to tire and affect their ability to perform normally.If a high voltage applied across the heart through chest defibrillator electrodes for a very brief period can cause the heart to stop and restart, it follows that a foreign low voltage applied to the same locations for hours might be expected to have an adverse effect on the same muscles.It also follows that those same muscles might not behave normally, casting doubt on the validity of the data recorded by the monitor.(b)(4).

• Brand Name: MOBILE CONTINUOUS OUTPATIENT TELEMETRY (MCOT)
• Type of Device: CARDIONET SENSOR
• Manufacturer (Section D): CARDIONET/ BIOTELEMETRY TECHNOLOGIES
• MDR Report Key: 6669460
• MDR Text Key: 78664292
• Report Number: MW5070635
• Device Sequence Number: 0
• Product Code: DSI
• Reporter Country Code: US
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Voluntary
• Reporter Occupation: Unknown
• Type of Report: Initial
• Report Date: 06/23/2017

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 06/23/2017
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Device Operator: Lay User/Patient
• Device Catalogue Number: 100-0028-02
• Device Lot Number: FCC ID: QB1-1011
• Was Device Available for Evaluation?: No
• Was Device Evaluated by Manufacturer?: No Information
• Type of Device Usage: N
• Patient Sequence Number: 1
• Patient Outcome(s): Disability
• Patient Age: 67 YR
• Patient Weight: 60