Pacemaker for sick sinus syndrome, now exercise tachycardia


I had a Pacemaker inserted Jan 2018 for sick sinus syndrome. For some reason the sinoatrial node was working 50% of the time and I was getting very dizzy (RHR in the 30’s). 

I also have ‘exercise intolerance’ so Oct 2018 the Dr increased the settings so that my heart would rise to the level of exercise. I run a lot and even completed an ultra marathon Sept 2018. 

Since the setting change I’ve had tachycardia whenever I exercise. I had the settings adjusted again 2 weeks ago after complaining my HR was in the 170’s and sometimes 180’s when doing a slow jog. I’m 45 yo woman. I also  have had severe pain in the centre of my chest while running a couple of weeks ago, but it stopped after a few minutes when I stopped running. I went to the GP and the cardiologist and they said probably nothing to worry about. The cardiologist did adjust the exercise settings in the PM down a notch to prevent more tachycardia. Both drs put the pain down to exercise induced angina. Then last week I had chest discomfort and slight pain where my heart was after running. It didn’t go away after a couple of hours so I went to the ER. They checked for heart attack, did some X-rays and other than high CK levels (in the 250’s), there was nothing they could find. I had a follow up CT scan as I’ve had this ‘discomfort’ on and off for over a year, but never for 2 hours. The CT showed nothing. I thought that the adjustment to the PM would have sorted the exercise tachycardia by now. But my HR is still in the 170’s and peaks in the 180’s even if I go really slow. The nurse at the ER also said that I’m completely reliant on the PM as it was always pacing when I was in hospital. 

I feel like I’m just complaining. That they might think it’s all in my head. Especially when the cardiologist checked my exercise HR on the PM monitor and said it was in the 140’s. I pointed out that was because I was stopping or walking to get the HR down (e.g. 30 sec jog: 30 sec walk) Now I’m not walking at all so I can show what the actual exercise rates are. And I haven’t collapsed. Which is the first question the dr’s ask. When I say no it’s like, well it’s not really a problem. Do I have to faint before I get taken seriously? Once I got dizzy and then disoriented and I had to ring my husband to find me in the park as I couldn’t recognise anymore where I was. Even though I run the route regularly. 

I’m worried I will one day faint or worse. 


don't be shy about going back

by Tracey_E - 2019-02-23 13:06:47

It's normal to take a few tries, or sometimes more than a few tries, to get the settings right so don't hesitate to go back again. If they treat  you like it's in your head, it's time to find another doctor. If you're just worried they're thinking that, then don't. Young active paced patients are rare and no two of us are alike so we can be challenging to get the settings right. Getting on a treadmill at the office so they can watch real time while we run can be helpful.

When you get up to 180+, is that paced or is your heart kicking in? If it's paced, it can be changed. Just because the pacer can get that high doesn't mean it should.  If it's you, then sometimes they can give us a low dose beta blocker to keep it from getting so high. Sometimes with SSS you pace at rest but your heart kicks in on its own once you get your rate up.

I was on a beta blocker for a few years for exercise induced svt. I never got over 150-155 with it. I'm not on it now. My stamina is better without it but I have to do walking intervals in order to keep my rate down when I run. If I just run, I stay at 170-180. My doc is ok with that and said it's ok to be that high but I'm not! It doesn't feel good if I stay there for more than a few minutes. I figured out how often to add in walking intervals to keep my average under 170. It took a few months, a lot of miles, and the cardiogram charts from my apple watch to figure out what works for me. So I run and let it get up for short intervals, but then walk and bring it down again. Frustrating to train hard and still have to take walk breaks, but I can run and feel good so I'll live with my turtle pace and try not to whine too much. 

Until you get it figured out, don't push yourself to the point you end up with angina or being disoriented. Whether they tell you it's ok to push that hard or not, whether they've figured out what's going on or not, something is clearly happening when you get that high so the safest thing to do is not get that high for now. 


Get on a treadmill stress test

by CyborgMike - 2019-02-23 19:22:23

Melanie, is the tachycardia a normal sinus rhythm (sinus tachycardia)? or is it Ventricular tachycardia, afib, or ?   

I also have SSS with exercise intolerance that invokes VT after my HR gets above 100-110. The VT sometimes shows up as a HR of 160 or often my HR monitors just don't show anything. In my case the VT was also associated with shortness of breath and lightheadedness, but would go away as soon as I stopped running/exercising. 

It's important to get on a treadmill and see the ECG, so you know what type of rhythm you have. A good EP will know if it is the pacemaker settings causing it or you have a second condition, as I do, based on the stress test. 

Keep pushing the docs. You need to self advocate if it isn't working for you. Get your own data. An Apple Watch with ECG is a great tool, especially for a runner with a pacemaker. 

Good luck!

Not sure which tachycardia

by Melanie - 2019-02-23 20:58:10

Thanks for the comments. I’m not sure which tachycardia it is. The cardiologist said he could do a stress test but that it’s probably a waste of time. I have a Garmin Forerunner 235 which measures my HR when running. Today on my ‘easy long run’ it got up to 187 bpm. And I started to get a mild headache but then the headache went away. I didn’t push myself so I didn’t feel dizzy. The exercise tachycardia is something new.

The pacemaker just kicks in when my HR goes below 60. Which it always does. 

I’m under investigation for Mitochondrial Disease too as my identical twin sister has the disease. It’s causing autonomic dysfunction which I guess could cause these new symptoms. I’m still waiting on test results to see if I do actually have the disease. Until I get a diagnosis for Mitochondrial Disease, the cardiologist hasn’t been focused on how the disease can impact my heart. Although he did explore the rare chance of a heart tumour which was ruled out by the CT scan. 

I’ll make another appointment with my cardiologist to get the PM checked again to see if that is somehow contributing to the tachycardia. 

stress test

by Tracey_E - 2019-02-23 21:44:52

I would ask for it anyway. He may not think it will be usefull but it might show them what's happening when you have symptoms.

If you are using rate response- and it sounds like you are- then in addition to not letting your rate get below 60 it's also giving you a boost when you exercise. All of this will show in a stress test, what's pacing and what is you and what's happening when you feel badly. 

187 sounds high

by CyborgMike - 2019-02-23 23:18:44

A max HR of 187 sounds too high for a 45yo runner. What was your max while running before the pacemaker?

it could be bad rate response (if enabled) or it could be something much worse like Ventricular tachycardia or one of a dozen other very bad types of tachy. The flutter of bad tachycardia will fool the watch or HR monitor into thinking it is a high heart rate, but really it could be one part of the heart having a type of electrical seizure. This is more probable if you see a big jump in your HR while running (like from 130 to 180) without a proportional exertion.

Again, if it were me I would stop running and get it diagnosed with a treadmill stress test. The headache is your body warning you. Don’t risk something more serious or damage to your heart.  



HR 6 months ago

by Melanie - 2019-02-24 05:34:05

Hi CyborgMike. My HR for around the same distance (14km) and slightly faster pace was on average 144. Although it did spike a few times and got to 165 at one point. Today the average was 169 but spike to 187 early on in the run. About 11 minutes in. The same thing happened when I had the intense pain in the middle of my chest a few weeks ago. It felt like several hard punches. When I stopped, the pain went away and didn’t come back. But I did notice when I checked my Garmin there was a spike in the HR just before the pain. And the same thing happened when I went on a walk the following day, but the pain wasn’t as intense. The ongoing discomfort which was directly where my heart is was more of a concern to the GP but not the cardiologist. But after 2 hours of discomfort and a few sharp pangs I went to the ER. They confirmed I hadn’t had a heart attack. 

I’ll definitely ask for the treadmill stress test. It takes about 8 minutes for the HR to get up so I hope they do the stress test for at least 10 minutes. 


by Tracey_E - 2019-02-24 10:21:15

Take your garmin read outs with you and add notes about when pain happens. They have their own benchmarks when they do a stress test so it'll be helpful to show them what to aim for.

Exercise Tach

by Czechmate - 2019-03-21 16:13:20

Just read this post.  I'm having the same issue and was doing the same tricks of trying to bring down the HR during running.  I've had the PM since 2016 and before that never had an issue with tach.  Now have a bunch of "high heart rate" or tach alerts when I run.  Once and a while the high heart rate keeps going after I'm done running and I have to manually bring on a vagal response to lower it.  Never had that problem the 10 years of running and racing prior to the PM installed.  The timing of these things with the PM install is too coincidental to ignore.  Like you, I'm flustered.  We are now going down the rabbit hole of trying to figure our which kind of tach it is.  All I want to do is turn the rate response off and see what happens.  Of couse, doc thinks that won't work.  I'm wearing an extra HR monitor for twenty days to get more data.  I still blame the PM for my exercise related issues and will insist the rate response be turned off as it's the only way I will be convinced otherwise.  I'm trying to cut back on stimulants during this time as well and request bloodwork.  Sometimes feels like the simpler solution is not always considered.  It's either drugs or surgery.         


by Melanie - 2019-03-21 21:24:01

Thanks Czechmate. I’ve tried cutting back on caffeine too. It’s made no difference unfortunately. I’ve since had other symptoms such as dizziness and nausea. It seems to correlate with a HR spike. So now I’m booked to wear a Holter monitor for 3 days. And I’ll go for a walk tomorrow and little jog on Sunday to see what the response is like. 

I’ve just been formally diagnosed with Mitochondrial Disease which causes autonomic dysfunction. Which could explain why the sinoatrial node is no longer pacing itself and the new exercise induced tachycardia. Although the simplest explanation could be low iron too. 


by Czechmate - 2019-03-27 19:15:08

Sorry hear about your disease.  I hope you find a long-term solution to everything.  I’ve been wearing a Bodyguardian monitor for about 6 days.  Today I went for a super easy jog (12 min pace) with some walking  as I’m recovering from a knee injury.  I went into tach sometime after 20 mins.  I stopped at 30 min and just let the heart race for about 3 min after stopping.  It was going about 180 and my pulse was soft.  I wasn’t faint or short of breath.  I pressed the event alert on the monitor several times.  Doc called me 30 minutes later.  They say I have exercise induced SVT.  Recommending ablation.  I’m scared because all of this is permanent.  Guess I’m in denial and just want to try it without the rate response first before going the ablation route.  I know it’s not something to mess around with either.  Just don’t get why it showed up after the PM install.  

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