HR Issue

on Sunday, November 16, 2014 at 11:35 PM

So I thought I would write a post about the HR issue in more detail in case people are googleing around finding similar symptoms.

The marathon has had me thinking a lot more about the HR issue now.  It's always been something I worried about, but it obviously hasn't caused me serious harm to date, but that's not to say that it won't.  I've read about Ryan Shay and Danny Kassap who were both high level professional marathoners who collapsed during races due to the heart issues and would later die. In fact, I heard that someone collapsed 10m from the finish line at the Hamilton half marathon and that the individual was an experienced runner who also died. Part of me worries that I might suffer the same fate.

The technical medical term for this phenomenon is a tachycardia and depending on what is causing it can mean it's extremely dangerous or just annoying.  

When it happens to me, I barely notice and most of the time, I only know because the HR display on my watch is telling me. The polar info I posted during my race report is one example, here's a better more clear example from a run.  This was from a  8 mile run that included 3x1600m interval session I did back in October.

It actually happened twice during this run.  It happened near the start, about 6 or so minutes in during the warmup when the HR (red line) jumps from a little over 125 to over 150, I ran with it like this for a few minutes and then started to walk when it then comes back down on it's own and then I continue with the warm up. I then get to the track when I immediately start into the intervals.  The first one is fine and the HR tops out at about 180 at the end of the interval, proceed with the recovery which involves a slow jog and as soon as start the second one, the HR jumps to over 200, after this interval, I start a walk recovery because I realize the HR is spiking, I think it actually recovers during the walk, but my pace dropped to 0 for a while and if I recall correctly, I think I did the squat maneuver just to make sure that it was low, I then proceed to walk the rest of the recovery and then do the third interval which is fine where the HR tops out at 185, and the HR issue doesn't return.  All three intervals are done at roughly the same pace so the drastic difference between interval 2 and the first and third isn't a result of pace difference.

While it happens randomly while I'm running, it most often  happens when I come to a stop after running and then restart suddenly (like with interval repeats), this makes stop light stops a pain in the behind because it will usually trigger an event.  I can usually get it to stop by doing the walking/squatting thing. This isn't a problem on long runs or intervals where I can throw in a walk recovery, but it becomes an issue when doing tempo runs where I like to do continuous running for between 4 and 7 miles. Breaking that into pieces to throw in a recovery isn't so great.  I was lucky enough this training cycle that I didn't have any HR issues when doing the tempo runs, but I did notice that the HR spikes seemed to be more frequent this training session during long runs. Other ways of getting it to stop involve what are known as vagal maneuvers which force the vagal nerve to send signals to slow down the heart, they involve holding one's breath or dipping the face into cold water or bearing down like you're having a bowel movement.  These are all difficult to do while running. I discovered the squat method while trying to do the bearing down thing. I'm not sure how one can pass a stool while standing up so the first couple of times I tried it, I would squat down, but I found the act of squatting was itself enough to get it to come down which I'm kinda thankful for.

Over the years, I've tried a number of different things to try to mitigate it. I'm constantly eating salt, which supposedly causes an increase in blood volume which supposedly helps to prevent it. I've been taking calcium&magnesium supplements which supposedly prevent it. I've cut out caffeine completely from my diet  which is supposedly another potential cause. Another potential cause is not getting enough sleep and this is one thing which I have difficulties with.  I can usually get by on 6 hours of sleep, but I find it hard to sleep for longer than that.  My body just naturally gets up after 6 hours.  I guess I need to figure out how to reprogram the internal alarm clock.

I did attempt to get this looked at a few years ago. Family doctor referred me for an echocardiogram and a stress test.  The echocardiogram did not reveal anything abnormal about my heart, and the stress test wasn't able to reproduce the HR spiking symptoms so the doctors' diagnosis was everything's fine, but I knew that something was still not quite right. I purchased an ECG monitor a few years ago on ebay, hoping that some blatantly obvious ECG problem would show itself, but while it's easy to spend $200 on an ECG device, the $100,000 medical degree that allows one to interpret it isn't so easy to come by. But hey if you're curious and can see a difference.

Normal at rest -HR 56
Tach, jog HR 176

The only difference I see is the tachycardia one is just faster.  The shape of the waveforms look pretty much the same. Ideally, I should have captured the ECG running at the same pace, both when it's spiking and when it's not.  It's just not easy to do since I have to run while carrying the ECG monitor with wires hooked up to my chest.  I did this experiment only once while running around a track back in June and I was excited to capture the tachycardia event with the monitor, but I realized after I should have planned it out a bit better. I'm thinking maybe I should try it out on a treadmill.  

The cause of tachycardia is usually a result of extra signal pathways in the heart that cause extra signals to make the heart beat faster.  The way to cure this is through an interesting procedure called a catheter ablation where they use drugs to force your heart into the spiking mode and a catheter is sent into the heart and the tissue that generates the extra signals are basically burned off. This is kinda scary cause after all this is your heart and if they get it wrong, there's a chance you're wearing a pace maker for life.  I've been reading recently that they've introduced a new technique where they use liquid nitrogen to first freeze the tissue to see if it solves the tachycardia problem first. If not, they let it thaw and start looking elsewhere so this at least offer the possibility of a do-over but it still seems kinda risky. 

In any event, I've decided to try and get this thing looked at again from a medical viewpoint and will hopefully get some more information this time around.  First appointment is tomorrow with family physician to try and get a referral to a cardiologist.