Lead Polarity Change

I am 100% pacer dependant and have a dual chamber device. I went in for my routine check-up the other day and the tech told me that one of my leads had changed polarity from bipolar to unipolar and that my impedances were fluctuating.
He said he had no idea why this was happening and was going to check with tech support to see if he could get some answers. I have not heard anything yet, and I am more than a bit concerned.
Has anyone else had this happen? Any ideas or suggestions as to what may be causing it?
Thanks so much!

4 Comments

Lead Polarity

by SMITTY - 2012-04-21 01:04:54


Hi Carol,

This is an area I'm anything but an expert in so I can't say I know why this is happening. But I will say that tech should be out digging ditches rather than doing PM checkups. He left you in suspense unnecessarily. Especially with you being PM dependant. Either unipolar or bipolar will serve your needs. It is just that bipolar gives a more stable PM operation and probably extends the battery life a little.

An oversimplification of what is going on is an electrical circuit has a positive and negative side. (Think of the positive and negative posts on a car battery) With a bipolar lead the electrical impulse (positive) goes to the point of contact in the heart and is then picked up by the negative part of the lead tip for the return to the PM to complete the circuit. With a unipolar lead the electrical impulse (positive) goes to the point of contact in the heart and then uses the body (negative) to complete the circuit back to the PM.

Again an oversimplification of impedance is a measure of the amount of resistance the electrical impulse is encountering to get to the heart. Why this is fluctuating I have no idea as I think of a change in impedance as being gradual but continuous.

While I can understand your concern I don't think you need to be. Your PM should continue to do the job for you even with these irregularities. If you do not get a reply Monday I say contact the Dr and tell him/her what that tech said and if that doesn't get an immediate response then copy the message you posted here and e-mail it to the manufacturer.

One last word, if you get another comment contradicting any, or all, of what I have said, believe them, not me.

My best to you,

Smitty

Peace of Mind

by Carol M - 2012-04-21 02:04:41

Smitty,
Thank you so much for your comment. It has helped to ease my mind (at least through the weekend...lol). I have had a PM since I was 16 and I am now 41. I had some issues with my first implant, but it has been smooth sailing ever since. I guess I took it for granted that nothing would ever go wrong. I'm still hoping that's the case, but it definitely caused a misstep to hear that something isn't "right".
Thanks again!!
Carol

bipoloar/unipolar

by manaman - 2012-04-28 10:04:58

I read your post here. I'm a bit confused myself. I have a lead issue (broken/frayed?) cannot get a straight answer. Anyway, I was UNIPOLAR (I think) and was changed to BIPOLAR (I think) to buy time. Didn't work though. Was put back (programed back to original state. I was not aware that this change from one to the other by itself. Thought it had to be done by tech or doctor!
Been chasing lead issue since last December 2,2011. Still not corrected and I can sympotize with you, it is not a good feeling!Cecil

polarity change

by Carol M - 2012-04-28 12:04:49

Cecil,
I had no idea they could change on their own either. I am just hoping they can reprogram mine. I am not due for a Pacer change for another 2 1/2 years. Would much rather wait and have everything done at once.
I go back Monday and they are going to try to reprogram it. Keeping my fingers crossed!
I really hope that they get you some answers. Its hard to believe they have let your situation go for so long. It just doesn't seem right.
best of luck to you!
Carol

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