lead moved and output turned up

Hi,

I had my dual chamber pacemaker inserted 23rd December 2008 for heart block, I have felt great until a few weeks ago when I started getting symptoms of heart failure again. Following really bad palpitations on Saturday I called my liaison nurse and he organised a pacemaker check today. The technician discovered a problem, and organised an x-ray. The upshot was that lead had moved- (I’m not sure which one though) as I’m sure the technician said one thing and consultant another. I’m assuming it is no longer attached although I could be wrong. They have turned the output up to maximum and will see me again in 6 weeks.
If someone could explain any of this to me I would be very grateful. Would they have turned up the output if the lead was still attached? If the lead isn’t attached does it need to be? Anything I should be thinking about?
I know this is all a bit vague. I know a lot about the structure of the heart and congenital heart defects but very little about the electrical conduction systems in the heart

8 Comments

Lead Moved

by SMITTY - 2009-11-30 08:11:50

Hello Vicki,

So that we are both on the same page, let's start with the basics. Our leads are attached and held in place on the pacemaker by screws. The other end is attached to the heart wall by whatever the attaching mechanism is on the other end. Some of these attaching devices look like cork screws and are literally screwed into the heart wall, although it is a very shallow penetration. Some leads have a barbs that looks some what like a fishhook and holds the lead to the heart wall with this hooking device. I'm sure there are others means used to insure the leads stay in contact with the heart wall but I'm not familiar with them. Since your pacemaker was implanted almost a year ago, I would guess that if a lead has come lose it will be on the end that is supposed to be in contact with the heart wall as these leads actually move with each heart beat. If the connection at the pacemaker had been faulty, I would think that would have shown up before now as there should be no movement at these connections.

During a checkup they check what is called impedance of the leads. This is a check to see how much of, or how well, the power impulse from the pacemaker is reaching the heart. As impedance increases more power output may be required to get the necessary amount to the heart chamber to make it contract. So if a lead has become disconnected or simply now has a lose contact with the heart as you see this will be identified by an increase in impedance of the particular lead.

If if the lead has come completely lose I would doubt that any amount of increase in the power output would be helpful. While on the on the other hand if a lead is simply lose then I can see why they may think an increase in power output may overcome the poor lead connection as a temporary measure. It is possible, I guess, that if it is just a poor connection the hope is that with a little time the lead may become better connected to the heart wall and avoid the necessity of having to replace a lead. To me this would be the consecrative approach. If the change in PM settings relieve your symptoms, but the lead impedance does not return to what is considered normal, the worst that can happen at the end of six weeks is you will have to have a new lead implanted, which is what would happened if the conservative approach had not been tried.

Now to put the final sentence on this page. Of course all I am doing is guess or speculating and I will now step aside and see what others have to say.

Good luck to you,

Smitty

Lead situation

by ElectricFrank - 2009-11-30 11:11:40

Smitty covered most of it well so I'll just add a few comments.

As Smitty mentioned modern leads are either attached to the heart with a spiral "corkscrew" type device or a barb on the end. When they are being installed either type will be pushed into the heart wall and if the screw type they will be rotated to secure them. If you think about it the cardiologist has a demanding task to accomplish this on a wildly thrashing heart wall. If the heart wall has a lot of fatty deposits or plaque it may interfere with the attachment being secure.

I can only guess what might have happened. For good contact it needs to be buried reasonably deep in the tissue so it could have come out part way. It could also have come completely out and then flopped around in the heart chamber until it hit the wall and reburied itself. In either case turning up the voltage would compensate for it. Actually, it could still be out and flopping around. Blood is very conductive so with a higher voltage it could still pace the heart.

Now for the bad news. Running the pacing voltage at maximum causes a high drain on the pacer battery. Where your pacer programmed to handle AV block will normally last for 5-7 years, running at full output can reduce that to half. Another thing to be considered is the effect of the higher voltage on the heart wall. High voltages are irritating to the heart. It should not be considered a permanent solution.

Even if the impedance returns to a more normal it only means that somehow the lead has found a better resting place. However, this doesn't mean it is well attached and won't come back out in the future. The lead needs to be replaced for reliable long term functioning. All too often this decision is based upon whether your insurance will pay for the procedure or considers it a warranty job.

frank

Leads

by tcrabtree85 - 2009-12-01 12:12:45

Hi,
I didn't have the chance to sit and read what Smitty and Frank wrote but I trust they gave you all the advice needed.
I just wanted to let you know my story though. A year ago I was in the same place as you where my lead had moved my output had been at the highest for a couple months prior. Well what happened was my lead dropped down and would not hit the right spot.
I am dependent on my pm and was hating being paced so much in my ventricles. I went to the ER where they showed that my pulse was running low they called in a pm rep who ran a lot of tests and determined my lead was giving such a weak signal.
A week later I had surgery to replace both my leads as some how they were both having a weak signal b/c for some time they had my voltage set to the highest it caused my battery to wear out also. I had 5 months left on it so they decided to replace my entire unit completely.
I hope that they will just replace yours instead of waiting so long and having to be faced with what I had too. If you have any questions please feel free to ask me.

Tammy

Thanks

by ElectricFrank - 2009-12-02 01:12:26

It helps to have a real story to make it easier to understand what Smitty and I said.

This is one of those situations where waiting to see what they want to do is a bad approach. It is our body they are messing with.

frank

lead moved

by vicki2806 - 2009-12-03 09:12:37

Thank you for your very helpful comments. I have a couple of more questions I hope you don't mind!
I live in Scotland so thankfully don't have to worry about insurance cover, and I know I can access my cardiologist quickly which helps too.
When I had my pacemaker checked in February it was pacing 86%, when I had it checked on Monday it had been pacing only 10%. I don't know if this drop is usual or if it is a result of the pacemaker not functioning properly. I had the checks at different hosptials so they didn't have my records and I didn't think about it until later.
Frank you said that running the pacemaker at high voltage could cause irritation to the walls of the heart. How would this manifest itself and what, if any, damage would this do to the heart.
Would I experience anything with my pacemaker running at full output? I'm feeling a bit weird, hard to explain, but I'm not keen on going back to hospital as I have a big university placcement to finish which I'm repeating because of getting my placemaker in last year!

Thanks again

Vicki

Question

by huntfishok - 2009-12-08 12:12:27

First the leads are attached either by the cork screw or by "fins" or "tines" not barbs. The tines and fins look similar to a fish's fins. They become lodged in the trebeculae of the inner muscle layer of the heart. They are easier to remove if needed in the future. Turning the output to max is a question of why. Did the lead dislodge and until it is able to be repositioned, the high output will work, maybe. If it is dislodged then it may not be capturing the heart with every output which will cause you to have symptomes. If a lead is a little lose, over time will not correct its performance. It will most likely develop Exit Block and need higher outputs for the long term, shortening your battery life of your pacemaker. High outputs are a bridge to repositioning of the lead or a doctors reluctance to reposition.

Andyz

by Andyz - 2009-12-11 03:12:40



I am required to have a complete removal of my PM which is positioned on my right hand side of my chest,where I also have 4 leads which have been painful and annoying for a number of years..

This is my 5th replacement and will be having a new system emplanted on my left side , i am also right handed and that also could have been creating an irritation..

I live close to Wellington New Zealand and my cardiologist has to fly down from Auckland..

This procedure will be performed on Tuesday next and late this afternoon he rang me to go over the concerns he has over the surgery..

He gives me the feeling that no patient has gone thru this procedure in New Zealand and did I really want to go ahead..

He left me feeling very nervy and surgests that I could bleed to death but that will not solve the problem...

Has any one had this procedure performed.....

cheers Andy New Zealand

update

by vicki2806 - 2009-12-18 06:12:20

Update on the situation- I've been to the cardiology department 4 times in the past 2 weeks, had an echo, holter and exercise test. The upshot is that I have sinus tachycardia. The EP people are not concerned about this as it is a sinus rhythmn, however it is impacting on me- I'm exhausted and waking up in the early hours with a racing heart, I have a feeling of pressure on the top of my chest. Basically I've to go back to the clinic on the 15th Jan, I have a feeling they won't be keen to do anything, however this is obviously a change for me.
Any thoughts?

Vicki

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