Wild heart rate fluctuations when exercising - Is this a concern?

[MarkSw]

I use a rowing machine for about 15 minutes daily, which has a heart rate monitor. At the start I have a rate of about 55 bpm. As I start the rate rises only slowly for the first 20-30 seconds to around 80 and then typically surges up to about 190, a rate that is typically sustained for about 1-2 minutes. The rate then suddenly drops to about 95 for perhaps another 3-4 minutes after which it slowly rises to about 120 bpm. Then it may surge again to about 170-180, for another minute or two, before dropping back down suddenly to around 95, and so on. When I finish rowing I monitor my recovery over one minute whereupon it slows only slowly over about 30 secs, from about 130 down to 110, and drops away almost instantly to around 65, from where it rises back to about 75 after a minute.

All this seems unrelated to how hard I am rowing, as I keep a fast and very even stroke rate throughout, giving myself a reasonably hard but not excessive workout. My expectation would be a rate that is related to the degree that I am working out, but I am actually seeing some quite erratic fluctuations. It doesn't cause me any discomfort, it just looks strange on the chart. Is this something that I should be concerned about?

I am s 48 year old male, 170 pounds, 6 feet in height, and I am on beta-blockers (Atenolol) for hyper-tension, which has successfully brought down by BP from typically 190/100 to circa 125/75. The only side effect was that I have fainted a few times for no apparent reason, although this seems to have gone away as I have become accustomed to the medication.

[zsheba]

A related discussion, re. was started.

[charchar]

Believe me I understand you are not a dr. Just thought you might have some information that you could share that might give people an idea on what these things mean .The reason i gave her weight was to let you know she was not over weight . No she is not anorexic but thanks for the concern and no it didn't offend me. I'm sure we will find out whats going on with her I have the best cardiologist around (in my opinion) but I appreciate your comments and also the comments of others.Its very interesting. Thanks agin.

[charchar]

hi, my daughter has had her holter test done for feeling dizzy and weak while sitting and when running feeling like she is going to pass out. and her test showed she has a slow heart rate and also it jumps way up. While she was sleeping it stayed in the 50's and then around 5:00 in the morning it surged to 170 bpm .so he done a echo test it showed she had a small leaky valve but he said not to worry about that. and he had her redo the holter and it showed where when she plays basketball it would jump to 190 bpm .he will see us again to let us know what he wants to do next. His nurse said he may want to put her on some meds. to slow it down some ..but wouldn't that make her heart rate even go slower when she is already feeling weak and dizzy when it runs in the 50's?? She is 17 and she isn't all that athletic She's never been able to really run hard because she starts getting sick.she is 5'3 98 lbs.So she should be able to do the normal things .

[Dr. Erik]

Definitely a bad monitor. It's happened to me a lot of times. Don't use the monitor or you'll drive yourself crazy.

[runnertom]

Having used heartrate monitors extensively, I might offer a couple of thoughts. I doubt if the quality of your monitor is the issue. I had similar problems of the monitor refusing to update itself due to my frequent PVCs. Watching its function closely while riding a bike, I noticed that under normal circumstances, it updates the pulserate about every 4 or 5 seconds. Apparently, it averages the pulse to pulse interval in that period and uses that to calculate a pulserate. If a PVC should occur during that time, the intervals are too variable and it will not update. In my case, the monitor would report an increasing pulserate up to 120 or so, and then appear to "stick" on a reading when my PVCs became frequent enough to appear in every measurement period. As my pulserate increased to greater than 150, it would again report normally since my PVCs tend to go away as the heartrate gets higher.
   The PVCs can be seen or inferred on my monitor in that the blinking heart icon does not blink when a PVC occurs. This appears to be a skipped beat in the otherwise normal rhythm. When these skips go away, the monitor updates normally.
   I was using a monitor made by Polar, which I think is the major among sports oriented monitors. However, I sought out other brands such as those provided with exercise equipment. They all seemed to have similar problems with PVCs, although some may have been somewhat better in that regard. It probably gets down to the amount of time that particular monitor averages the pulserate over and the likelihood of a PVC occurring during that time.
   My recommendation would be to pay close attention to the possibility of PVCs, either by having someone feel your pulse while exercising or watching the pulse indicator on the monitor (if it has one).
   I have also had some problems with the efficiency of the electrical contacts. That seems somewhat unlikely here if the "symptoms" are as predictable as you imply.

[captmorgan]

I hate to say it but I definately have afib and I definately have the same responses. I have a top of the line Polar 810 that lets you download the info to your computer. When the fluctuations are happening my printout is like a seismograph during an earthquake! The pacs and pvcs also show up like the other poster mentioned.

[mightymuppet]

Sounds like an error in the monitor to me...I've witnessed the same thing with home monitors and bike riding monitors at my fitness gym....I think you'd feel your heartrate pounding quite hard if it suddenly rushed to 190bpm all of a sudden.
I could be wrong though!

[CCF-M.D.-RCJ]

MarkSw,

Thanks for the post.

You may wish to see the post from Runner2 (I think that was his name) about 7-10 days ago.

I think that by far the most likely explanation for the variance in the heart rate is from a poorly functioning heart monitor.  The current technology in heart monitors follows the adage "you get what you pay for".

A very unlikely possibility is that you develop afib during exercise.

An easy way to sort this out would be to (1) buy a better monitor, (2) have someone measure your pulse during the exercise, or (3) have a supervised treadmill exercise test.

Also, make sure your doctor knows about the feinting spells, this is important information for him/her to know.

Hope that helps.