Phonak Compilot and Medtronic Surescan

My wife has just had a Medtronic A2DR01 implanted to treat her bradycardia and it appears to be performing well. She wears Phonak hearing aids and enjoys use of the Compilot streamer, a bluetooth device that communicates with her aids via a neckloop radiating a radio-frequency signal. Phonak warns categorically that PM patients should not use the ComPilot.
(1) Would a 6" offset from the loop prevent interference?
(2) Is there any reason to believe that newer devices such as the A2DR01 would be immune from such interference?
(3) In the worst case, how does the patient experience interference should it occur; does it temporarily block pacing or could it reset the device (which I understand causes a fixed 85 bpm pacing)?

5 Comments

Should be OK

by Theknotguy - 2015-08-21 02:08:58

Most of the warnings on equipment concerning PM's is just that, a warning. It's a CYA advisory put there by lawyers.

You shouldn't have any interference between the PM and the Phonak hearing aids. The "radio"/"Communications" part of the PM is turned off unless it is being read. With the radio part turned off there can't be any interference.

During a PM reading, I don't think the Phonak will broadcast a powerful enough signal to even bother the PM. Tests at the University of Michigan determined a radio signal had to be within two inches of an implanted PM to cause any problems. For security reasons, they didn't indicate how powerful the signal had to be but it had to be more powerful than what powers a bluetooth device. Since the Phonak device is at head level, it's more than six inches from the PM.

Between the distance and the weak signal, I don't feel anything would be powerful enough to bother the PM.

I jump started a car and was leaning over two different car engines while running. The alternators were broadcasting interference all over the radio spectrum. I didn't have any problems with my PM. Also the alternators would be more powerful than what is needed to power a bluetooth device.

Hope everything else continues to go well for you.

Amazing

by Janenotarzan - 2015-08-21 04:08:22

What I learn on this site : )

Medtronic response re ComPilot

by Pixie - 2015-08-22 04:08:27

(correction to title of previous comment)
BTW, the net consequence of a falsely sensed action potential on the leads should be supression of the PM's stimulus to the heart. Doesn't seem so bad for an assistive device , cf. an obligatory one as in AV-node ablated patients.

Medtronic's response re Compiot

by Pixie - 2015-08-22 04:08:55

I queried the Medtronic site on this subject. They responded (quite promptly by e-mail) that the 6 inch rule would apply. This should be feasible: the Phonak BT receiver is worn as a pendant at sternum level, the neckloop will have to be guided away from the PM with a clip. I remain uncertain as to the nature of radiated interference from the neckloop. If it is anything like the telecoil receivers that HA wearers use in public places, the signal will be at audio frequencies.

The point made by Theknotguy that the PM receiver is OFF until turned ON with an external strong magnet should lay to rest any possibility of resetting the PM.

However, I wonder if an additional concern is that electromagnetic radiation (such as in an induction loop) will generate weak voltage on the sensing leads from the heart which will be interpreted as an action potential.

ComPilot

by donr - 2015-08-23 04:08:56

IO wore one once upon a time. I wear a pair of Phonak HA's & have for several years. I never even thought about the effect of the ComPilot when I put it on. Neither did my PM!

Realize that the Medtronic response was reviewed by their General Counsel, who is interested in protecting them against lawsuits. I have no lawyers to review my advice.

All I know is that it never affected my PM.

I gave the device up as worse than worthless after several days. To my knowledge, My PM never was affected. Signal too weak.

Donr

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