Heart Rate Goes Up to 226bpm then drops to 30bpm

Hi,

       I am a runner and I have noticed a weird issue when I work out. Sometimes if I push myself for the first 5 minutes of a workout, rather it be running or the elliptical, my heart rate goes to a very high peak, then drops down to a lower level. In the past I have noticed it drop when it gets to about 180pbm about 5 minutes into a heavy cardio workout then it would drop down to about 80 for the remainder of the workout. This past weekend I did a relay run and my heart rate monitor recorded my heart rate going to 226bpm then dropped to 30 bpm then averaged out to about 60-70 bpm during a extreme hill run during a race. When this happens the first 5 minutes I get tired but when I push through it after the first few minutes, all of the sudden it seems like I am not even tired and I can run forever. I have noticed it a few times while running and alot on the elliptical. Has anyone seen anything like this? You can look at this particular run by going to my Garmin Connect Link...

http://connect.garmin.com/activity/117330722

       From that page if you scroll down on the right hand side you will see my speed/pace, elevation, and heart rate on the chart being recorded at the same times during the race. As you can see it dont make sense... I have recorded this kind of even a few times. So at this point just wondering...

Steven

[is_something_wrong]

My first thought is that your monitor is wrong. I would say that no one in the world could run up a hill with heart rate below 60 BPM or run at all with heart rate 30-38 BPM. No one, not even top athletes.

That said, you may have an arrhythmia where the monitor is only able to pick up some of the heart beats (like atrial fibrillation) and I definitely recommend that you ask your doctor for a stress test or a monitor where not only the pulse rate is seen, but the EKG (measures the electrical activity in the heart).

You can also measure the heart rate on your wrist or neck to see if your monitor is wrong, but if you have symptoms (which you describe) you should see a doctor before you do strenous exercise again.

[yogacat]

I definately agree.  I have occasional afib. I have had one long major episode in July and many afib flutters.  When I do the elipitical, or use the incline on the treadmill, I go from 70's to 180 really fast, and stay for a minute or 2 and slowly drop back to 70, My dr. said this is my afib flutter.  
Hopefully your dr. will check you with holtier monitor.  If not, I would suggest you have a bp monitor with an irregular heart dectector.   I would not know I was in afib because I have no symptoms, other than fatigue.  The irregular heart dectector picks it up once or twice a week.

[yogacat]

PS  .  With my afib. unless I am in it, it does not show up on stress test or EKG.    I have had many ekg's and the only time it showed up was when I was diagnosed.

[stevies_stuff]

I agree it is weird that is why I posted it on here. I have seen it happen in the past just not to this extreme of going up to 226 then dropping to 30's. To calculate my max heart rate i was told to do the 220 - my age (33) So for it to go to 226 seems odd. Saying that during the run I felt great and felt I could go on forever if I didnt have to hand it off in the relay. My heart rate chest monitor has captured it in the past going up to 180 then dropping down to the 80's, 90's. Most of my other runs are normal in my eyes, so I dont know if my heart rate strap would be acting up? It only captures it like this 2 total times. At the gym I see it often on the eliptical like YogaCat mentioned. I have had several ekg's and my resting heart rate at the time of my last one maybe 8 months ago was in the lower 50's. If I do a stress test what would that show? I mean for this to occur it has to be a high tempo workout from my experience in the past. Would a stress test prove it? If this is indeed a correct heart rate monitor, then do I have to worry about something?

[is_something_wrong]

Hello.

1) During an arrhythmia (if that's what you have) max heart rate doesn't matter. An arrhythmia may easily provide a heart rate of 200, 250, or above 300 for that matter, but in that case the consequence is fainting and often worse consequences, as the heart isn't able to fill between the beats, so cardiac output is zero. Luckily, arrhythmias rarely get that rapid.

2) It's the slow heart rhythm that makes me question if the monitor is wrong (and if it's wrong calculating the slow heart rhythm it may be wrong calculating the rapid rhythm). It's impossible to exercise with a heart rate below 50. If you're running uphill, I would guess the body needs a cardiac output of at least 15 liter/minute. That would mean that your heart would have to pump 300 ml of blood for each beat. Not even top athletes have a stroke volume above 180-200 ml, so that's impossible.

What can be possible though, is that you have an irregular rhythm which isn't completely captured by the monitor, that for example every third or fourth beat is captured. A heart rate monitor is mechanical, so you need a certain pulse in order for the monitor to capture it, different from an EKG recorder that monitors the electrical activity, regardless of what pulse wave is produced.

You should see your doctor regarding this.

[stevies_stuff]

Thanks, I made a apointment to see my doctor. I am going to print out the output and show it to him. I am going to ask for a stress test to see what it shows. I have seen it happen at the gym on the ellipitcal like I said but not to this extreme. And this is the second time running that it has dropped, but not this extreme either. So the EKG is just a instant recorder at the time, so I think a stress test would be better this way I can see if it is actually something to be concerned about. Thanks for your comments, the other option is to get a new heart rate chest strap and see if it happens down the road again. But your right, my heart rate would have been impossible to be in the 30's.

[tj_74]

I am curious what was the outcome of your visit to the doctor.  I had a similar experience first noticed during my first Ironman last November however with me I don't have the extreme high spikes. BTW the extreme high spikes on garmin monitors can be sometimes caused by friction of non cotton t-shirts.  
When it happened to me my HR dropped to 44 while walking 5 miles from the finish of the marathon portion then the HR monitor stopped reading my hr.  I was using Garmin 310 watch with HR monitor.  I did feel dizzy and felt like close to passing out. This happened again 2 weeks after the race during a very easy stationary bike ride 5 minutes into the workout.  Again very slow HR reading, feeling very dizzy, close to passing out.  I suspected that perhaps my HR monitor had a low battery as it hasn't been changed in over 2 years but the feeling of dizziness was very scary.  I did see a cardiologist but he wasn't concerned and explained it that I likely had a "increased vagal tone" and that I likely was dehydrated.  He couldn't explain why it happened 2 weeks later when I was totally rested at the beginning of easy bike workout. He also didn't want me to take any other tests since I had a stress test 2 years prior which was normal.   I am now waiting to see another cardiologist for a second opinion.  My normal resting heart rate is about 44/50 but never when moving.

[littlegreenman1]

If the chest strap is too loose and it's slipping - they give funky readings.
I looked at the garmin on the OP here and the pulse looks impossibly low for the physical output. Just no  way.

Have you confirmed your heart rate slowness by hand?

My resting HR is in the 40-50's as well, but in exertion I hang in the 160-170 range.

I had SVT which would render charts, like the following:
http://connect.garmin.com/activity/32390799 - this was a particularly bad effort! SVT after SVT after SVT!!