Pacemaker Tolerances

Some newbie thoughts:

If my pacemaker is set at 80bpm and has not varied from this so far until this morning, then when I used my blood pressure cuff, the reading is 86 bpm, what then are the permissible tolerance variations? I know that when they ablate the AV node they will set it lower, but I just wondered how you can tell the pacemaker is working properly....

PS Can a pacemaker stop without warning and would this be fatal after AV node ablation? Sorry if these are inane questions, but these things pass through your thoughts especially at night!

5 Comments

Phew!!

by JoMarie - 2014-02-25 01:02:26

Thank you for your informed and sensible observations. I had just a few hours to make up my mind whether to agree to a pacemaker, or Amiodorone drugs, or a further now risky ablation, so I felt a bit railroaded really.

I understand about the lower pacing now, but not if the rate goes extra fast, which is what my problem was in the first place. I have a dual chamber rate responsive one (I think), so will that pull down a heartbeat rising too high? I understand it will not cure my AFib and SVT but will bring it to a level which will be tolerable for me (sic).

Misunderstanding

by golden_snitch - 2014-02-25 02:02:25

Hi JoMarie!

Unfortunately, you understood something completely wrong here. The pacemaker will not be able to do anything about your atrial fibrillation and SVT. A pacemaker can only do something about slow heart rates and pauses, nothing about tachycardia. It is simply overrun by fast heart rhythms. I'm sorry if your cardio hasn't explained this well to you.

You had the AV-node ablation, so that the AV-node no longer passes the fast or irregular electrical impulses, that are coming from your atria, on to the ventricles. Your atria will continue to fibrillate or beat fast, but these signals don't get through into the ventricles. Instead, the ventricles are now paced at an appropriate rate by your pacemaker. So, while the atria might still be going fast, your ventricles will beat regularly at a rate that's adaquate for your level of activity. Good thing is that you'll no longer need antiarrhythmic drugs to treat the Afib or SVT. Bad thing, you need to continue your blood thinning medication.

Usually this "ablate & pace" approach, which includes ablating the AV-node and putting in a pacemaker, is used to treat highly symptomatic patients with permanent atrial fibrillation in whom every other therapy has failed. I hope that you had exhausted all other options, like cardioversions, anti-arrhythmic drugs and pulmonary vein isolation (special ablation technique that directly targets the Afib), before you had the AV-node ablation done. It's not used often as it leaves the patient with 100% ventricular pacing and, as many would be put, 100% pacer dependency.

BUT as Don already pointed out, even if the AV-node has been ablated, the ventricles can normally produce an escape rhythm. It might take a few seconds to kick in and it is really slow, around 20-40bpm, but it keeps you alive. So, if your pacer should ever fail all of a sudden - which happens very rarely -, you will most likely not die.

Best wishes
Inga

Heart rate

by Theknotguy - 2014-02-25 05:02:30

Your heart rate can vary widely. I was in cardio rehab this AM and my heart rate went from 60 bpm up to 121 bpm as I was exercising. The rates are normal.

It's not unusual for the heart rate to vary by as much as 10 to 20 bpm. Sometimes the medications can affect your heart rate. Sometimes emotions can affect your heart beats. Emotions can sometimes have a stronger effect than you think.

Right after I got home from having my collapse and the new PM, I was concerned about my blood pressure. I mentally "talked" myself into high blood pressure and an accelerated heart rate. Called the EMT's. Fast trip to the hospital where they gave me morphine to calm me down. Nothing else was wrong other than my mental attitude

So if your heart isn't racing and you aren't short of breath, your heart rate is probably OK.

Hang in there. You've got a lot of life to live!

Theknotguy

Whoa, Whoa!!!!!

by donr - 2014-02-25 08:02:27

Jo: You have the PM all wrong!!!!! But you are a Newbie, so that is understandable!

A whole bunch of points to teach you.

1) Your PM does NOT fix your heart at a certain rate. That 80 BPM is just a "Floor," a lower limit on rate that it will NOT let your heart go below. Your heart is permitted to beat at any rate it wants as long as it is above the 80 BPM.. Tolerance is a word that has no significance to the operation of your PM /Heart combination.

I will come back in another comment & tell you more about the "Floor" of your PM & how it keeps you from going below it. Too long to stick in here.

2) About the only concrete indication that your PM is NOT working correctly is if you catch your HR well below the 80 BPM level At this point in your career as a Host, just assume that it is, other than the 80 BPM issue. They are THAT reliable. I could write you a book about reliability, but now it would put you into a state known as sensory overload w/ info.

3) Can a PM stop instantly w/o warning? Of course it can. Can your heart stop instantly w/o warning? Of course it can. ANY device can stop w/o warning. I'd be lying to you if I said otherwise. The question you want answered is WILL my PM stop w/o warning. The answer is a resounding PROBABLY NOT! They are just that reliable. Over their projected 10 yr lifespan, they will just keep on pacing & are more reliable than your native heart. Come back in a month or so & I'll write you a monograph on their reliability.

3)Yep - those thoughts do, indeed, pass through your mind at night when it is dark, quiet & you have nothing to do but listen to someone else snore to keep you awake.

No, you probably will not die if the pm suddenly quits on you post-ablation. You better hear from a whole bunch of hosts living w/ that condition. Among them is a marvelous woman named Inga (Golden_Snitch) who lives in Berlin. She will give you the whole 9 yards on living w/ series ablations & being 100% PM dependent. She will talk about a little thingy called an "Escape" capability of the ventricles. So stop worrying needlessly about that.

Very good questions - not at all inane for a Newbie.

That's why we are here.

Donr

Pacing

by JoMarie - 2014-02-26 05:02:18

I have had two failed ablations for paroxysmal AFib and it was noted that I have very random firings within the atria and the likelihood of striking gold was becoming slim as the areas left to work on were 'thin walled' and therefore risky. I am still on increased doses of Flecainide and Bisoprolol. I once had bradycardia of about 46, but haven't seen anything other than 66 now for ages, until the crisis arose.

After the second ablation, things seemed to get out of hand and then for the first time the atrial tachycardia arrived at about 133 together with raised BP, alternating with AFib. The second time this happened I was admitted to the ward and the three alternatives were presented. The pacemaker was implanted about two weeks ago, but I have yet to take the step of the AV node ablation which will be scheduled very soon.

I can well understand the anxiety factor. This tinnitus I have sounds like an echocardiogram squelchy beat and I can cope during the day, but listening to it at night limping along, well I am not sleeping too well right now! I am also feeling a kind of dread at the final step of the further ablation of the node.

You know you're wired when...

Jerry & The Pacemakers is your favorite band.

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