Pacemaker Not Working?

thoughts

by Tracey_E - 2017-07-28 16:09:13

First thought is if you have av block, you don't need rate response so don't worry about that. Rate response is for when the sinus node doesn't increase during activity. With av block, our sinus node works just fine, we only need the pacer to make the ventricles beat when the atria does. 

Second thought, what your rate used to be has absolutely nothing to do with what your rate is now so forget those numbers. You can also ignore those charts with target rates. It'll take some time to figure out your new, paced normal. Before you were paced but when you were in block, there were atrial beats that didn't have corresponding ventricular beats so your actual rate would have been higher had the heart been in sync. 

I'm no doctor but my immediate thought is 150 is not enough, btdt and it's like hitting a wall. Does yours not go higher than that or does he not want to turn it up higher than that?  It's plenty for some people but you are young and fit and it's perfectly normal to get higher than that when you work out.There is at least one of the mri compatible devices that only goes to 150 but most of them can go to 180, a few will do 220. My upper limit is 190. I never hit that, 160-170 is my norm when exercising, but it's good to have a cushion. If your sinus (atrial rate) gets over 150, then the heart is out of sync because the pacer can only pace the ventricles up to your upper limit, and it will zap our strength instantly.

When you ride your bike, are you getting to 150 and staying there? If yes, go back and insist on a treadmill test. Doesn't much matter if it's a bike or treadmill, it's the exertion that you want to show them, see if the sinus rate is over 150. Or a Holter can tell them a lot.

L.ast thought, some doctors don't have many young and active patients so they don't have much experience with us. Some doctors themselves are out of shape, in which case they don't get our need to exercise and can write us off. Don't settle for either one. If they aren't used to active patients, they can learn or you need to find someone else. If they write you off and tell you to get used to it, find a doctor who is into fitness and gets it. Both my cardio and sjm rep are runners so I've been fortunate that every time Ive had a problem, they've been willing to go all out to find an answer so I can be as active as I want.

You have a simple problem, you should be able to do what you want now that you're paced. Don't settle for less. 

From The Athlete

by Peter P. - 2017-07-29 20:14:48

Wow; thanks for the detailed reply!

Regarding the 150bpm limit: I'm under the impression the pacemaker isn't limiting my heart to 150, but the pacemaker will not assist above that rate. I'm 57 years old so I'm assuming my max heart rate will be in the 160-170 range; close enough that I shouldn't worry about the 150 pacemaker ceiling, no?

I took to wearing a heart rate monitor just to see if I was still missing beats because when I checked my carotid artery, it felt like it and I wondered whether this was my problem. Sure enough, the heart rate monitor confirmed what my pulse was telling me. But the heart rate monitor also told me I'm not going anywhere near 150bpm before I start to crater; that starts to occur above say, 110bpm.

Your phrase, "zap your strength instantly" pretty accurately describes what happens to me. It starts at about 22 minutes into a ride and dare I continue to even try to keep the heart rate up, the deleterious effects I feel will last for hours after the workout. It feels so bad I consider heading to the E.R., but the effects usually subside by the next day.

Good suggestion on the Holter monitor. I had considered asking them to hook me up with one again so I could "press the button" during every ride when I melt down and give them an idea of what was happening. The funny thing is, the first time I suggested putting my on a treadmill and mentioned the 22 minute start of symptoms, the doc essentially said, "We can't wait that long.", as if the patient's healt wasn't worth their time. I'm definitely going to suggest a Holter monitor at my upcoming appointment.

It's hard for me to comprehend that the pacemaker docs haven't a clue how to deal with athletes as I'd expect I'm not the first one they have seen. You'd think they were listening to Charlie Brown's prinicipal!

I'll report back once this gets squared away. Again, thanks for your reply.

150

by Tracey_E - 2017-07-29 21:57:18

The heart can always go as fast as it wants on its own. The pacer is a gas pedal, not a brake. Can it go higher than 150 on its own? Sure. Will it? Not always, we have issues, that's why we're paced in the first place. 

150 can mean two things. With atrial pacing, which is when rate response kicks in (that's what you're hearing when you read about cyclists having problems) means it will artificially get your atrial rate only up as high as 150. With av block we rarely need atrial pacing so this doesn't apply to us.

150 in regards to ventricular pacing means it will only keep the ventricles beating in sync with the atria up to 150. And yes, if your sinus rate is 160-170 and your ventricles are only doing 150 you will most definitely feel it. For me it can be anything from mildly dizzy to black around the edges and feeling like I'm going to pass out to arms and legs like lead. My old pacer (I'm on #5) only went to 170 and I was regularly maxing out so this happened to me several times every workout. It was too frustrating so I eventually went on beta blockers to keep my rate down, then when I got a new one last year they gave me one that goes higher so now it's not an issue. Long way of saying I'm a bit of an expert on how it feels when you max out lol. Yes, the atria can go as fast as it wants. If you are in block, the ventricles are limited to the upper limit.

But if you are only at 110 or so when it happens, you aren't maxing out and something else is going on. I don't see what the big deal is doing a 20 minute treadmill, in reality the way they do it won't be 20 minutes anyway. They are preset to increase both speed and incline every so many minutes so it pushes us pretty hard fairly quickly.

If they are going to be weird about it, just push for the holter. Or go get another opinion. JMHO, but I won't have a doctor again who isn't into fitness and also comfortable with very active patients. The very best thing we can do for ourselves is to stay fit, our pacers should help with that not hinder.  Anyone who doesn't get that isn't the right doc for me. 

I recently switched to a new practice, one that specializes in adult congenital, and he automatically does a holter on every paced patient every year. He said he can figure out 80% of the settings from talking to us and looking at the pacer interrogation, he uses the holter to fine tune the other 20%. I hadn't heard of that before but it makes sense.  

Update

by Peter P. - 2017-09-10 10:07:42

It's been a while and while my issue hasn't been squared away, I thought I'd post anyway.

I had a stress test performed while a team monitored my EKG on my left, and a team monitored the pacemaker operation on my right. They saw nothing unusual and said the pacemaker was performing properly.

So they gave me a Holter monitor for a week and told me to "push the button" whenever I felt symptoms while riding.

At a visit with the electrophysiologist a week later, he said my A-V interval was too long. He switched the pacemaker from MVP mode to DDD mode so it's pacing the ventricle constantly vs. on demand. There's been MAYBE  a 10-15% improvement. He also told me to keep the Holter monitor on for a month and continue to use it. We meet again then to see what adjustments can be made.

FYI: I did manage to see my settings on the screen and my upper limit is set to 170bpm, not 150 as earlier reported.