need interpretation of monitor report

Cardiologist's office sent latest quarterly report via email, and I need some help interpreting a few things.  

Under heading: Atrial Lead Undersensing, it says:

"Atrial lead signal amplitude suboptimal. Stability of the signal over time needs to be monitored"

"Suboptimal" means not optimal.  What kind(s) of problems does this cause, and should I be asking doctor about it?  My next FTF appointment isn't till January. 

Another section says "Stored EGMs are consistent with or suggestive of premature ventricular contractions ,1%"  Interpretation???

And:  "A Pacing 40%, RV pacing 99% AT/AF burden 1%"  I guess that means right ventricle needs paced 99% of the time, which jives with what they told me at last appt.  But what does the other stuff in that line mean?  Thanks.



by Penguin - 2023-11-15 15:29:36

Hi Lillian, 

I know how you feel - it's a different language entirely! 

I'd ring up for an explanation about sub optimal lead issue.  Others on here may be able to explain better than me, so I'll leave that one to them. 

The other sections are easier: 

"Stored EGMs are consistent with or suggestive of premature ventricular contractions ,1%''  This means that EGMs / ECGs which the device records and stores for various cardiac events show that you are having PVCs.  These are ectopic ventricular beats. 1% is the burden of PVCs.  Sounds like nothing, but 1% will equate to thousands of PVCs.  You may feel them or not. They can feel like thuds or missed beats.

Cardiologists are interested in the % burden because it expresses the 'toll' on your heart of various different functions that the pacemaker performs.  That's why it's a % rather than a number.

"A Pacing 40%, RV pacing 99% AT/AF burden 1%"  

A.Pacing or AP = atrial pacing. This means that the pacemaker is pacing your atria (top of the heart) 40%.  This is neither high nor low and means that the pacemaker is firing to replace your sinus node function (at the top of the heart).

RV pacing = right ventricular pacing. This means that the pacemaker is pacing your ventricle at 99%. This is a v.high % and would make sense if you have an AV node conduction issue.

AT/AF -= Atrial Tachycardia / Atrial Fibrillation. These are arrhythmia which occur in the top chambers of the heart - the atria. The overall burden is 1%. 

Note: Pacemaker statistics don't differentiate between AT and A.Fib. 

Again your overall burden is low, but this usually equates to a fair number of events.  

With all of these statistics how you feel is more important than the %..  

That's a very basic 'translation'.  I hope it's helpful to you. 




If you're losing your atrial pacing lead sensing then you may need the lead to be replaced

by crustyg - 2023-11-15 15:36:51

A lot of your device's operation depends on reliable sensing of atrial activations.

One of the biggest challenges for a PM is ensuring that it doesn't deliver a pacing signal soon after an electrical activation.  For a few tens of milliseconds, an external pacing signal directly to the heart muscle will do nothing - the tissue can't respond.  But for a short time after that, a pacing impulse could trigger AFib or VFib - which is not good.

There's a lot of development and experience gone into ensuring that the above scenario doesn't happen, but overall it depends on your device being able to sense an activation, or wait long enough that it's almost impossible for a pacing output to cause trouble - but the wait might be a real problem leading to low HR => low BP.

Your EP-doc is keen to avoid replacement of your RA lead, but if it proves essential then it has to be done.

PVCs: many of us have them.  A few, not a problem, a lot - a potential problem, an increasing number - perhaps an indicator of an issue with heart muscle health and time for some (additional?) medication, and they can reduce blood pumped from the heart.  Being blunt - increasing PVCs *might* lead to NSVT, might lead to VF (game over if you don't already have an ICD).

suboptimal Atrial lead undersensing

by PacedNRunning - 2023-11-15 21:10:54

Undersensing of the pacemaker means that the lead is not sensing atrial activity and if it does not see the atria working "p" wave, then it will pace the atrium. They can also oversense. It can oversense what it thinks is atrial activity and cause the device to not pace because it thinks your own heart is doing the work.  Suboptimal means they like the lead to sense a certain range of P waves.  I just looked this up because I'm in the same boat and not sure what the plan of action is. I believe they like a range of 0.6mv to 4.0mv. But ideal is >2mv.  Don't quote me. You could google this.  For now, they keep an eye on it. Please let us know what the results are. I don't see my EP until January as well. I have monthly monitoring transmissions reports and so they are keeping a close eye on mine. 

Atrial undersensing

by Rch - 2023-11-16 01:43:32


Atrial under sensing could initiate A Fib or PMT. So, you would need to have your device tech reprogram the pacemaker sooner than January. If you feel any flutters or palpitations now, they could be related to the atrial undersensing. Please discuss your concern via a reply to the Cardiologist's email and seek an earlier appointment or at least let him be aware of your concerns. 

need interpretation of monitor report

by Lillian S. - 2023-11-17 10:40:16

I took your advice and called cardiol's office. Asked about the atrial undersensing and now I can't recall/didn't fully understand exactly what the nurse said, something about averaging over time.  She said she didn't see anything abnormal on the report, nothing to be concerned about. She said over time leads may need to be replaced when they wear out, but I don't need that yet as they are only 2 years old.

If I had palpitations in the recent past, I didn't feel them.  And she said she didn't see any report of afib incidents, which is an improvement over the last report.  I'm making an appointment for my yearly checkup for January and I guess I shouldn't worry in the meantime. 


by PacedNRunning - 2023-11-21 16:05:55

Glad you called and got reassurance. We have to trust our medical team to a certain point. I would hope if it's something urgent they would have us come in sooner. I'll update when I see my EP in Jan 

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