Pacemaker Misfiring Nightly

2:00 to 3:00AM

by AgentX86 - 2024-05-13 19:08:41

It's probably always the same time.  This is undoubtably the self-test/calibration feature doing its thing.  I does things like measure and adjusting your sensing and capture voltages and margins.  There may other housekeeping items that your EP has told it to do. Most don't feel it, but if it bothers you just tell them to turn it off.

Atrial Lead Oversensing Fairfield

by RioTeresa - 2024-05-13 22:13:01

Thank you for your input AgentX86. I haven’t heard from the doctor yet but received the results of my transmission (interrogation) and it shows 98 events of Atrial Tachycardia up to 353 bpm since April 15 and Atrial lead oversensing Fairfield (whatever that is?). Atrial lead warning April 15 and Atrial lead oversensing non-physiologic, cannot rule out lead noise. So what this tells me is there’s a problem with the Atrial lead. At least this one is the screw type so I’m not concerned about replacing it. I had the old hook types implanted in 1995 but those were extracted in 2011. I’m relieved to know what’s going on now but not looking forward to tonight’s pounding chest. I need sleep!

Thank you again for your input,

Teresa

Oversensing

by JaneJ - 2024-05-14 02:40:29

Hi Teresa, it sounds (like you had said) that there maybe an issue with your atrial lead.  I hope your dr calls you back soon and you can get things figured out.  98 events is a lot!   I would probably call them again soon if you don't hear from them.  Let us know what they say.  Take care ❤️

Article re: P Wave Oversensing

by Penguin - 2024-05-14 03:26:22

Not sure if this is helpful or not?

https://www.cardiocases.com/en/pacingdefibrillation/clinical-situation/icd/p-wave-oversensing-0

Yes I have experienced tachy events during the night

by Gemita - 2024-05-14 05:14:59

Teresa, firstly I don’t think we can jump to any final conclusions just yet about the actual cause of your atrial high rate episodes that seem to occur for around 10 mins at the same time each night.  A dysfunctional lead would no doubt reveal itself at any time during a 24 hour period, not just specifically between 2 and 3 am.  You may need external holter monitoring in addition to your pacemaker monitoring to determine why this is happening, whether the nightly checks are causing interference, leading to tachy events.  I used to get this when I had a loop recorder implant, together with my pacemaker implant.  It used to happen at around 1 am as my loop recorder was interrogated.  I had awful tachycardia events caused by interference.  

No doubt your team will need to see you in clinic to carry out some checks on the integrity of your atrial lead and to see whether your settings need adjusting.  For example whether you are switching appropriately to a non tracking atrial mode when your atrial high rate episodes are detected?  If mode switch isn’t happening, your ventricles will be pushed too fast and you will be feeling the pounding chest.  I see you have a history of persistent Atrial Tachyarrhythmias, including Flutter.

There are lots of questions to ask Teresa, so please don’t assume anything at this point.  Your lead may not be as bad as you fear.  I recall I used to have over 1,500 events regularly detected in a 3 month period, but these were often short lived tachy events.  The sensitivity of my atrial lead has been adjusted several times.

Some technical stuff follows separately in case it helps.  Please keep us updated Teresa and take good care.

Tracking of atrial arrhythmias, myopotentials (from skeletal muscle activity), electromagnetic interference, or lead noise 

by Gemita - 2024-05-14 05:19:23

Any rapid atrial rhythm can be sensed by the atrial lead. Tracking for example of Atrial Tachycardia can cause ventricular pacing at the maximum tracking rate, particularly if the Mode Switch setting option is not active.  Additionally, inappropriate mode switches can sometimes occur.  For example, far field events or frequent ectopic beats can result in high atrial counters and inappropriate detection and classification of events as atrial tachyarrhythmia events.  

Dual-chamber pacemakers capable of "tracking" the atrial rhythm recognize very rapid atrial rates and initiate mode switch to a non-tracking mode when specific criteria are met. If the pacemaker senses non-physiologic activity on the atrial channel (e.g. noise) or inappropriately senses ventricular activity on the atrial sensing channel, (termed far field R wave [FFRW] sensing), the detected atrial rate may not represent a true atrial tachyarrhythmia. If this artificially detected atrial rate meets criteria for the mode switch algorithm, inappropriate mode switching will occur.

Tracking of atrial noise (such as what may occur with electromagnetic interference and myopotentials from chest wall muscles) can also be sensed by the pacemaker and cause pacing at the upper rate limit. Myopotential (skeletal muscle activity tracking) is more common with unipolar leads which may be sensed by a pacemaker and falsely interpreted as a depolarization. 

Over-sensing occurs when the pacemaker detects electrical activity that it should not normally encounter and incorrectly interprets as intrinsic cardiac activity.  Over-sensing may occur due to multiple factors, including lead noise or artefact caused by electromagnetic interference from machinery and sources of high voltage, pacemaker Crosstalk due to over-sensing of signal in the opposite chamber, lead failure due to insulation break or fracture, myopotential from skeletal muscle activity.  

I hope a clinic appointment and full testing of your pacemaker and leads will be arranged quickly for you. 

Atrial Lead Fractured & Reversed Polarity

by RioTeresa - 2024-05-16 00:26:48

Thank you all so much for your help and kind wishes. Gemita, you get it! The article or information you posted here is exactly what is happening. Thank you so much! I saw my EP yesterday for a pacer check and she said the Atrial lead is fractured & had reversed polarity which was what was causing those hard nightly thumps, (apparently at other times as well but not bothering me as much since I’m awake and busy). My heart is beating all kinds of different speeds & the VP is up to 469 bpm!! She made several unusual adjustments so that it won’t run through the nightly tests anymore and a lot of technical stuff I can’t begin to go into, but I was finally able to sleep last night for the first time in weeks. I do still feel tachycardias when I’m relaxed but that’s nothing unusual for me.

I need a lead extraction, which is involved since I’m 100% paced & it’s my 2nd, so I’m meeting with the surgeon next week. Hopefully I’ll be rewired and pacing properly soon. 

My background: I had ventricular tachycardia as a teen and it got out of control, six times or more a day, blacking out while on beta blockers in my 20’s, until I eventually had cardiac ablations in my early 30’s, the first two failed, the third caused complete heart block resulting in pacemaker implant at age 34. I feel blessed to have the pacemaker compared to life with the VT & beta blockers. 

Everyone on here is so thoughtful and kind to take the time to help with kind words, well wishes & information. I sincerely appreciate it. Thank you so much! 

Teresa ❤️