Exercise-induced supraventricular tachycardia

helzbelz1984

Hi everyone,

I recently posted about a 'mysterious condition' that I've been having for the past 3 years. Following lots of help from people on here, and after speaking briefly with a cardiologist, I think that this mysterious condition could be "exercise induced supraventricular tachycardia" (what a mouthful!).

Obviously I'm going to be pursuing a proper diagnosis (I'm seeing my GP tomorrow), but it would be interesting to see whether anyone else has this and whether my symptoms sound similar....

I first noticed it back in 2012. I was at my fittest - I'd set a PB half-marathon at 1:39, and a 5k PB of 21:15. Then one day I was out for my usual 6 mile run and I suddenly felt like I was drained of energy, really breathless and 'heavy'. Fatigued, i guess is the best word to describe it. I hadnt been running any faster than usual and so it seemed really random. As soon as I stopped, the feeling went, but I had to 'walk-run' for the remainder of the 6 miles.

Ever since then the same thing has been happening on and off. Sometimes I can go for weeks without it happening so bad. It's never perfect, but a 'good' day is where I don't have to stop and recover.  Back in April was the last 'good phase' - I managed to run 13 miles in 1:42, and a full marathon in 3:55. But since then it's been happening on almost every run and when it's really bad I can't even keep up a conversational pace without having to stop and recover. I've had to drop out of several marathons and half marathons because of this too.

Initially I thought it was a problem with my breathing and so the Dr gave me an asthma inhaler. This didn't work and, after speaking to other people with exercise induced asthma, the fact that my breathlessness stopped as soon as I stopped is not consistent with asthma. Plus it didnt really feel like it was localised to my lungs - more of a whole body fatigue. I then went back to my GP and got referred for a resting ECG - this didnt show anything except bradycardia (48 bpm) and, because my resting HR is slow, I have an extra heart beat. This is a normal variant apparently. I've also had loads of blood tests done , for ameamia and thyroid problems and whatever else - they all came back normal and the GP has given up trying to diagnose me.

But, as it's gotten so bad these past few weeks, I've been on a bit of a mission to find out what it is. Plus recently I've noticed palpitations after walking up the stairs, which are also accompanied by this breathless feeling, so I'm sure it's something to do with my heart. So I went for a 8 mile run the other day with my heart rate monitor on, which I havent worn for years, and found that my average HR is 178bpm (on a slow run) with the occassional spikes up to 230 (when I'm still just plodding along on flat ground)! Obviously this could be interference, but if it's not then this could be indicative of SVT, right? Plus, before I developed this condition, my HR would average around 65% of my max HR on a long slow run whereas now it's 96% of my max HR (I'm 30) (yes, I know that 220-age isnt an accurate predictor of max HR but, relatively speaking, it appears to be a lot faster!).

Another thing that makes me think that this could be SVT is that I randomly discovered that coughing or holding my breath (not that easy when running!) tends to help end the episode. I thought this was psychological and so didnt think anything of it, but after researching about SVT, I discovered that these techniques are recommended to help stimulate the vagel nerves.

It would be interesting to hear whether any of you have experienced similar symptoms and have received a diagnosis. Also, is there anything that you find helps?

Thanks !!

 

sarahmg

Hi Helzbelz1984, I seem to be experiencing the exact same symptoms as you.... I have run marathons and was training for one. I noticed I was tired on a few runs but didn't really worry. Then I noticed my heart rate was high even just walking - normally my running heart rate is 80 - 85 bpm. When I checked my heart rate data I could see my heart had been jumping from 80 to 160 for many of my runs, sometimes for just a km, but more recently for the whole run. I saw the Dr who didn't take me very seriously and thought it was anxiety so I rested and it seemed to go away and I continued training with a normal heart rate. 2 weeks later it clicked back out again on a short run and now every time I exert myself it goes high and if I run it goes to 150 to 180, even up to 190. I had an echo and ECG which showed nothing and now I am waiting for a further appointment. It is so frustrating as I have had to drop out of the marathon and am not running at all as it just sends my heart into its max zone straight away, even when I am just plodding. This has persisted for 4 weeks now. Did you get a diagnosis for your problem?

Tiago_Fzz

Hi all, have you found the causes of your SVT sarahmg and helzbelz1984? 
I'm 36 year's old and I used to run a lot, but on the last two years I stopped running that offten, so in was decided to start to be the "running machine" and started training on November 2017, everything was going fine until my first SVT while running on 25 March 2018, I was about to cross the 10k when suddenly I felt something on my chest, lack of strength and air, some pain, I couldn't bread no more, I felt like I was going to collapse right there... when I looked to my Garmin I was with 185bpm while stopped, and I remembered that I had checked a few seconds before while going down the street and i had 145bpm, I started to panic thinking I was going to have a stroke out there alone without anyone to assist me... after a few minutes my HR dropped to 145bpm ( this tooked 7min between 145 to 185 and back to 145...)  it was a very scary experience... I did some exams, stress test, 24h holter, echocardiogram, ECG (bradycardia), and they all checked normal, but I this week I started running again, I went for a 10k run 2 days ago, everything checked ok, while this morning I was running while my wife was ridding her bike, I had done like just 3k when suddenly there was the hit on the chest, the lack of air, and some dizziness, but mutch more weaker than the previous experience... this time I was with my wife who helped me to calm down, because if you get scare can be worst my HR went from 130 to 185 stayed there for 30 seconds and it went down again. After this I rested for 10min and went back on foot to the car, 3k more... 
My wife says it could be a panic attack, but I was feeling great, and I think shouldn't it happen when I'm not running? 
I still don't know what it was, but I know what I felt and it wasn't panic (I had panic attacks 7 year's ago and I know how do they feel)
Does anyone know anything about this? 
What can trigger this while running?

(Sorry for my English)

Coolas65

Hi, I think I’m suffering similar symptoms to you guys. Had the problem for 3 years now. I used to be able to run 10k in 37 minutes with no issues. I then trained for London marathon which I did in 3 & half hours, but ever since then I’ve struggled to complete a 10k & sometimes 5k even! Just raced in a 4 mile race tonight. Started with first 5k at 3:40 pace, then got rising feeling, struggle to breathe but not wheezing & had to stop 4/5 times before struggling over finish. Typical of my races now. If try to run through just feel dizzy. Had ecg but nothing wrong with heart. Have low blood pressure - standing of around 45. Gp not really interested in helping as nothing otherwise wrong. Really getting me down. Can anyone offer anything as going to quit otherwise?