Under sensing problem

I had some complications because of  difficulty accessing the vein during initial pacemaker placement 4.5 weeks ago. As a result, the ventricular lead is under sensing my natural heart rate. A few days post-op, the pacemaker clinic said the lower lead was only sensing at 40% "sometimes". They reassured me that it is not dangerous and can be resolved a few different ways  but that they will recheck at the 6 week mark. They confirmed that the pacemaker is working "well enough" to fully resolve my AV block.

Needless to say, I'm anxious and disappointed that things are not working 100%. It's bad enough needing a pacemaker and having a difficult surgery with a long, painful recovery.

My questions for the forum are:

1. Has anyone had a sensing problem that improved between week 0 and week 6?

2. Has anyone needed to have the sensing threshold adjusted to resolve under sensing?

3. Under what circumstances do they decide to operate and try to improve lead placement?

4. How bad is lead repositioning surgery?

I'm mostly doing a good job of putting this out of my mind and visualizing point #1 above. It's a challenge  though!



by Tracey_E - 2019-11-27 11:21:09

So sorry to hear you are having problems. I have no idea what the odds are of it resolving itself, but reposition surgery should be easier than the first surgery because they'll go in the same place. Most of the pain is from the pocket, and that won't change.

If the position is such that they have to turn the juice way up to get the signal through, then I'd want to have it repositioned because that will significantly decrease battery life. Right now it's easy to move it to a better spot. Once it's been in a few months, it gets harder. After a year, it'll be in so tight it would take a special laser to get it out. So if you are going to move it, sooner is better. 

Is it the atrial or ventricle lead? If it's atrial I might be tempted to leave it alone. With av block we typically use the atrial lead for information, the pacing is all ventricular. 


by Pacemaker_Sally - 2019-11-27 22:54:18

Thanks Tracey_E. It is the right ventricular lead that is under sensing. My '6-weeks post op' appointment is the week after next and I'll post an update when I have more information. 

Ventricular electrode too loose and misplaced

by Sybarite - 2019-11-29 09:52:27

Hello Sally, I do my best in my bad English:


Let me tell you about my experience
1. bradycardia since I was 50
2. in March 2019 (I'm 81) I have a Biotronik placed in Belgium
3. The convalescent weeks go by, and I do not feel well. Fatigue, vertigo. My cardiologist insists: I have to get used to my PM.
4. I believe my cardiologist and I go home along the Andes.
5. My situation does not change, I feel more and more tired.
Can not walk more than 50 meters.  Life is no longer possible.
6. I return to Belgium and see another cardiologist. This cardiologist
makes me do a stress test on bike. And at the peak of the stress test the cardiologist notices  arythmias !!!
7. I am given a CardioScan which shows that the ventricular electrode is too slack/loose and poorly inserted into the ventricle.
8. I underwent a second surgery to put the electrode in the right place
9. Second convalescence but this time with my left arm immobilized for 3 weeks.
10. A new stress test shows no more arythmia
11. after 6 weeks, I go home along the Andes.
Nobody told me that recovery is important because a network of fibrous tissues (stratum) around the PM is formed, and this stratum protects it.
-------------------------------------------------- -------------------------------------------
After two months ;
A. I resumed my activities in the mountains.
B. I work all day in my property, I walk, I do the gym, Tai Chi, I work as before.
C. I also took up mountain habits: every 40 minutes my iPhone rings and I drink 300 ml of water. At the end of the day I drank at least 3 liters of water and I never pee yellow.
D. That's it. I am 90% as before and happy to live.
E. For the possible tiredness I take Phosphorus that gives me my homeopath.

Feel free to question me. 

I thank you very much PACEMAKERCLUB, because it is while reading the forum that I understood

1. that the sale of PM represents a lot of money
2. that cardiologists do not always tell the truth to the patient 

3. malpratices exist

Thank you Sybarite!

by Pacemaker_Sally - 2019-11-29 12:26:25

Thank you for sharing your actual experience. Complications are fortunately rare and my biggest fear is that mine will be swept under the rug. 
That must be extra challenging that your cardiologists are so far away in Belgium when you live in the mountains of SA! 

More information

by Pacemaker_Sally - 2019-11-30 12:59:39

yesterday, I called my surgeon's office, told them I was feeling really anxious about my pacemaker working less than 100% and asked if there would be any follow up with the surgeon. 
I felt hugely reassured to hear that the surgeon responded to the under sensing issue identified at the pacemaker clinic with a written report on next steps, depending on the outcome of my next visit to the PM clinic in 10 days. 
My anxiety is a little lower today but obviously the possibility of more surgery is unsettling. 
I think it is important to recognize that the PM leads are intended to be there "for life" and if they're not right, they need to be adjusted as soon after implant as possible. 

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