BPM question

BPM

by Julros - 2021-05-16 01:47:46

It depends on what your underlying heart rate is. For me, my underlying heart rate is 30, so I can only go my max of 140. Before my ablation, my max was 80. I was told the initial settings of 60-130 were  factory pre-set and they did adjust my upper rate at my request, but won't let me go higher "due to my age". I'm 64. Your pacer tech should be able to adjust for your lifestyle in subsequent interogations. 

High heart rate

by Theknotguy - 2021-05-16 07:28:28

If your heart rate goes above 130 the pacemaker just sits there and watches.  It doesn't do anything.  It means your heart rate above 130 isn't paced and you go back to using your biological pacemaker.  

You'll want to ask your EP if that's a problem.  In my case I get some really weird heartbeat situations because I have heart block and the beating signals don't get transmitted correctly.  Fortunately I usually don't go into that high of a rate.  Also, as julros pointed out, they can sometimes set the pacemaker upper limits into your range.  However, since the tech isn't allowed to "practice" medicine, you EP may want to make that call.  

Otherwise, I hope your adjustment to your pacemaker goes well. 

Thank you!

by Lovesthesun41 - 2021-05-16 08:37:38

Thank you Julros and Theknotguy for your replies I appreciate it. I'm both excited and a bit nervous to get back to it. Fingers crossed 🤞

Max heart rate

by AgentX86 - 2021-05-16 16:51:19

It's unclear to me (I haven't gone back through your posts) why you have the PM but I'm guessing that you have heart block (the reason for the BiV pacemaker).   In this case, your upper limit is the fastest your PM will drive your ventricles.  Your atria would still be governed by your SI node. 

If the above is the case, then when your max limit is reached, the ventrical half of the pacemaker will stop tracking the atria and they'll start beating on their own, at times working with each other but most of the tiem working against each other.  You're probably going to feel this decoupling and you're not going to like it. 

You should be able to go somewhat higher due to age alone but there may be a good reason your EP doesn't want you to.  More likely, he wants to see how things go before raising it and won't if you don't ask.  If you're limited or feel horrible when you hit the brick wall(*) then ask to have it raised.  He may do it in small steps, or may not.  You might have to sweet talk him into it but if there isn't a really good reason not to (and this should be explained) he'll probably relent and raise it.  It might take some cajoling but it should go one way (raised) the other (reasons why not).

(*) It's worse than a brick wall in that it doen't just stop you from advancing. The dyssynronyt actually subtracts from your performance so it's more of a performance reset to a much lower level.  Instantly, you go from more or less from an oxygen in/co2 out equalibrium to your muscles being quite oxygen starved.

I've never had this happen because I'm 100% in dyssynchrony so don't experience the switch.  I'm always on the wrong side of the curve so compensate in other ways.  My rate is limited to 130 for other reasons.  My EP won't budge and it really doesn't matter much to me.  I rarely get to 120.  I think the highest Iv'e reached while walking (my exercise of choice) is 114.  My floor is set to 70bpm, daytime, so it isn't much of an increase.

Just to add to Agent's experience

by crustyg - 2021-05-17 06:50:54

I can achieve the same issue for short periods when out on my road bike.  SA-node useless, so normally 100% paced RA - obviously severe CI.  My escape rhythm can get me up to about 110-115BPM if there's enough emotional drive (==sympathetic nerve stimulation), so I can arrive at a hill from a period of freewheeling, HR about 80BPM or less.  Start working the legs, escape rhythm kicks in *but* it's ventricles only, no pre-filling of ventricles with blood from atrial contractions.  Within a few seconds legs turn to jelly (not enough oxygenated blood) and I feel terrible.

Over next 20-30s PM Rate Response builds, drives atria to a higher rate than escape rhythm so A=>V sync restored.  Blood supply rapidly increases and I feel sick as the lactate + whatever washes out from the oxygen-starved muscles.  Then muscles start to recover and I can pedal away up the hill.

So, exactly as Agent says, it's actually worse than hitting 'The Wall' (in running terms) - I actually feel terrible for 30-40s - then it passes and I'm pleased with the box in my chest.

I also started out post PM at 50-130BPM, but quickly got my EP-doc to give me 160BPM maxHR after about 5 weeks.

Life is all about choices.

Thank you!

by Lovesthesun41 - 2021-05-17 20:18:24

Thank you AgentX86 and crusty for your explanations. I appreciate your taking the time to respond. I'm going to a class tomorrow so fingers crossed!