PM crashing during exercise

My dual chamber PM regularly but randomly crashes during exercise. For example, I will get my heart rate up somewhere between 90 and 130 and then it will suddenly crash down to somewhere between 45 and 68 beats where it will stay for about 30 seconds before suddenly kicking in again somewhere over 110. Has anyone else experienced this or had it diagnosed?

7 Comments

count

by Tracey_E - 2009-08-20 04:08:22

I wouldn't depend on the Polar for the rate, the pm can interfere with its signal and mess with the accuracy. I'd stop exercising and count.

I assume they've done a stress test? It's frustrating when you can't duplicate it for them! They can't fix it if they don't know what it is.

40 yrs might be the record here!

PM settings and exercise problems

by mango - 2009-08-20 04:08:33

Thanks for your response. I've had many checkups to adjust the settings, and changing my upper rate from 150 to 170 seems to reduce the frequency of these events, but it hasn't eliminated the problem. Trouble is, it is random and not something I can recreate for them on demand (as they asked me to try to do yesterday by running up and down stairs in the hospital stairwell). One of the things they told me was that my lower rate was already set at 60 so it was impossible for my rate to fall below that. I can only tell them what I saw and experienced using my polar monitor readout, which was that when this happened ealier in the week, I was wearing my polar monitor and it said my heartrate went down to 45. I think they don't believe this is happening to me, which is massively frustrating. I will take your suggestion to record dates and times - that's a good idea. I've had a pacemaker for 40 years, and only had this problem in the last 9 years. I've been complaining about it for years, but they haven't been able to diagnose it or eliminate it, other than to say that it may be ectopic beats which are normal and usually don't bother people. No one's ever suggested either of the conditions you refer to, so I will check those out and ask them about it at my next checkup. Thanks so much for your response, I really appreciate it.

How do you know this is happening?

by COBradyBunch - 2009-08-20 04:08:45

I exercise nearly daily and use a Polar HRM and have found that while my 'Watch' is pretty accurate since I have had my PM installed (I am only set for the PM to kick in when my HR drops below 50 - Have a resting HR of around 60) some of the machines I use at the gym will show my actual HR and then suddenly they will be showing either 1/2 or 1/3 (45-75) or my actual HR (usually somewhere between 130 - 150). I check my watch and it still shows the HR I expect and a quick 6 second pulse count also shows my watch is right. So if you are using a HRM strap with gym machines it might be the strap battery is old or your machines just don't sync well with the strap.

I guess the first question is what are you using to get this HR number? Next question is do you feel the drop in HR (sudden loss of energy or power)?

loss of power/weakness

by mango - 2009-08-20 05:08:41

Hi and thanks again for your replies. To answer the first question, I was using the polar heart rate monitor that I purchased at a healthy heart clinic run out of my local hospital. They advised that while the rate shown on it may be different by a beat or two from my actual rate, it would be pretty reliably accurate. I have used it both in conjunction with cardio machines that show a difference of a beat or two (I. e. my polar wristwatch says my heart rate is 110 and the machine monnitor says 109) and I have used it just out walking without any machines. The drop in HR sometimes (but not always) shows up briefly on the cardio maching monitor, although I've founf that it's picked up better on my own writswatch.

To answer the second question, I absolutely do feel the drop in HR. I can sense it happening without putting my fingers on my pulse to count, and I can sense it kicking back in. When it happens, I have to stop immediately because I feel tremendous and sudden weakness, as if I just need to stop and stand up against a wall so the wall can hold me up. Within a few seconds after the HR restoring itself (usually after about 30 seconds), I am good to go again. Although I haven't counted, when I do put my fingers on my pulse I can feel that my HR has cut down drafmatically, I would estimate about half of what it was.

They have done a stress test, but it only records snapshots and hasn't shown this drop. I'm scheduled to be put on a two week monitor in a week or so and am hoping that will show them what I'm talking about. And you are right, in fairness, it's pretty tough to fix when they can't see what is happening. But for that they would have to be by my side for a couple of days - which, hopefully is what the upcoming test will do.

I got my first pacemaker when I was 5 and I'm now 46, so yes, I've had a few! I never knew anyone else with a pacemaker growing up, and have lived a pretty normal life, so have never had the need to reach out to a community like this. But now that I have found you all, I am so glad for the opportunity to ask some questions and get some help. They have told me at the pacemaker clinic that they have never heard of this problem before, but I can't imagine I'm the first person with a PM to have run into this. Thank everyone for your time and thoughts - much appreciated, and if you have any other suggestions, please let me know.

Interesting info...

by COBradyBunch - 2009-08-20 05:08:57

Might just be the typical legal lingo but did find this:

http://www.polarusa.com/us-en/support/faqs?product=&category=Products&documenttitle=Pacemaker+and+Polar+Heart+Rate+Monitor&document=/gip/PEUS1kb-public.nsf/web_cat/85256F470048B0BC852574C50074627B

And something from Boston Sci about accuracy:

http://www.bostonscientific.com/templatedata/imports/HTML/CRM/A_Closer_Look/pdfs/ACL_Polar_Heart_Rate_Monitors_080408.pdf



settings

by Tracey_E - 2009-08-20 06:08:53

It sounds like your settings need adjusted, I'd call and ask to be checked. Make a note of the day and time it happens, that will help them pinpoint it. Several things can cause that, SSS and chronotopic incompetence come to mind. They should be able to adjust your settings to prevent the dips.

What is your lower limit? 45 is low for a lower limit.

similar symptoms

by BuddyOne - 2009-08-21 12:08:04

Hi Mango

I have similar symptoms with my pm. I've had the pm for bradycardia for a little over 3 years and felt good for the 1st year. The past two years I've experienced my heart rate dropping in half on a consistent basis. My max track (St. Jude dual) used to be 180, but I could never reach max because it would cut at 140-145 down to 70-77. This would happen on a treadmill at the gym, out on the street, and at the cardiologist on the treadmill. Always happened at about the 6 min. mark. Max track was progressively reduced from 180, 170, 160, 150, 140 with multiple tweaking of the settings, with the same results. Had an ablation/EP study in June that was suppose to finally address it, but that too did not resolve the issue. The EP finally lowered my max track to 130 (in theory, if it cut out at 140 plus, it wouldn't do it anymore because it wouldn't go above 130), but same results, only alot quicker and worse. I couldn;t go for 7 minutes in a paddle boat at a local amusement park (had to sit for 20 minutes after the ride) or ride a razr (foot scooter) with my son for 3 1/2 minutes.

Went to the EP a couple of days ago and he believes that the lead to the lower chamber has too much scar tissue around it and it is causing the pm to go into a loop (scar tissue blocking some of the signals). Wants to replace the lower lead (tinge?) to one with a screw for better conduction.

As for the holter monitors, I found that those aren't as reliable for what you are experiencing because the printouts usually have too many artifacts, channels drop out, etc. Ask your doc for a standard 2 minute Bruce protocol on the treadmill and I bet you'll have your results for the doc.

One last thing, the polar straps are fairly accurate most of the time, but do pick up interference from other sources and sometimes conflict if you are on an equipment with a built in hr monitor. Pick up an inexpensive oxymeter (50-60 bucks) on amazon. Slips on your finger and reads the pulse with infarred through the finger. I compared one to the computer when I went for a treadmill stress test and a couple of days ago when I had the pm interogated, read pretty much the same on both.

Good luck,

Al

http://www.pacemakerclub.com/public/jpage/1/p/story/a/storypage/sid/12986/content.do

You know you're wired when...

You have a little piece of high-tech in your chest.

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