Athlete with various types of heart block

Hi, I'm new to this forum but am finding it enormously useful.
I'm 45 and scheduled for pacemaker insertion on Monday and wanted to see if anyone has similar experiences to my own.

I'm an avid cyclist and runner, cycling about 100miles/ week and running about 15miles, the cycling volume has reduced from 200miles per week prior to the covid pandemic. I've always had a low heart rate, typically in the 50s and high 40s but over the last 4-5 years this has reduced to mid 30s at rest (lower when sleeping). I've been suffering from fatigue increasingly over the last 5 years, dizziness and light headedness, and unable to concentrate, get extreme and sudden onset of tiredness if I've been sitting for too long - I feel like I am twice my actual age. When exercising my heart rate maxes out at 167bpm, and I feel great for about an hour after, but really have to force myself to do it. I have a VO2 Max of 59.8, in part due to my low heart rate.

last October I visited my GP again to discuss the fatigue and light headedness, but this time he put me on an ecg and found I have a very weird heart rhythm and had me hospitalised the same day. I was discharged from hospital after a day of ECG monitoring with symptomatic bradycardia and second degree, type 1 heart block.

My rhythm follows this pattern:

Excercise: First Degree Heart Block with wide QRS but no dropped beats and max at 167

Walking: Second degree, type 1 heart block at 70-80 bpm

Rest/work (desk based): Second degree, type 1 heart block at 35-40bpm with less frequent junctional escape and what looks like a complete heart block (regular P to P intervals but no relation to the QRS).

Sleep: similar to rest but at 30-35bpm and occasional A-Fib alerts on my Apple Watch 

I have been seeing a cardiologist to evaluate the rhythm and there is still confusion about the junctional escape / complete block. I have had an MRI and that shows athletic adaptation of the heart with enlarged ventricles and mild mitral regurgitation. 

Long story, but I am now scheduled for a dual chamber pacemaker insertion, I'm glad to have some kind of resolution but am pretty anxious now as I wait for Monday to come. But I'm hopeful to regain some energy return to normality and feel like I'm still 45... ..and continue cycling!


It's not unknown

by crustyg - 2024-01-30 09:57:15

I suspect it's as much to do with high vagal tone as anything structural.  The AV-node has two nerve supplies - one sympathetic (fight or flight) and one parasympathetic, and this latter increases the refractory period during which the AV-node won't conduct another atrial activation to the ventricles/bundle of His.

Folk with enlarged, athletic hearts have a strong vagal influence, partly to keep BP under control. If every HB pushes a lot of blood out into the aorta - which becomes less elastic with age - then in the short term there are only two things that keep BP down.

1 Reduced heart rate, 2 Reduced force of contraction of each HB.

And achieving 1 involves slowing down SA-node activations *and* increasing AV-node refractory period.  Whether this leads to formal HB (PR invterval > 120ms) and conduction issues is, I believe, debatable.

It's all very personal: I was actually asking (==pleading) with my EP-doc for a PM!  And just as well: at implant resting HR 42BPM, 10months later, resting HR (PM off), 28BPM.

So unfair

by Lavender - 2024-01-30 11:04:31

You athletes do what we're told to do and so many have pacemakers after a lifetime of training.  It's unfair. Your hearts should be stellar.

A guy I know biked 35 miles daily and walked daily no matter the weather. He had a quad bypass in his late 50's but kept up his biking and hiking routine into his late 80's. He was 89 years old when he got his pacemaker- three months before I got mine. He's old enough to be my father. This guy was in top shape and ate well-all the stuff we are told to eat. He died this week at age 92 from congestive heart failure. 

He had a great life and a long one. Perhaps it was because he took good care of his body. But so many young guys get pacemakers!  I know the electrical system of the heart fails without regard to age, race, etc., but I would think being athletic would preserve the structural (plumbing) part of the heart. 

God go with you on Monday. I'm sure that after a brief recovery, you will be back doing what you love! ❤️‍🩹


by Tracey_E - 2024-01-30 11:12:41

If the fatigue is coming from the low rates, you will feel a lot better once you are paced!

Are you seeing cardiologist or electrophysiologist? EP's are cardiologists with specialty in electrical issues. They do pacers all day long. Ideally, you want an EP who has a lot of other athlete patients. EP's will do the actual surgery, so I prefer to see an EP rather than a cardiologist who refers me out for the surgery itself.

Theoretically with heart block the sinus node is working normally and we don't need the pacer to raise it for us (rate response). It's just playing follow the leader and making sure the ventricles beat when the atria does, so we don't need rate response. There are some pacers that do a much better job for cyclists than others. Odds are you don't need it, but I would still want one with a breathing based rate response just in case you need it down the road. The ones based on motion (most of the ones from Medtronic and Abbott) don't pick up on cycling. 


by Tracey_E - 2024-01-30 11:23:58

1. You can't fight genetics

2. No amount of exercise is going to prevent electrical issues

3. There is evidence that years of very heavy exercise (competitive level, not just working out to be fit) can have the opposite effect on the heart. I participate in a FB group of athletes with heart conditions and you'd be shocked how many fairly young, extremely fit, elite athletes end up with heart attacks, pacers, etc. 


by Gotrhythm - 2024-01-30 14:22:48

You asked for similar experiences. Though I am not an avid cyclist, your symptoms and diagnosis sound very like mine.

If you have to have a heart issue, our conditions are the ones that pacemakers are the very best at.

Unfortunately, cylcling adds a extra wrinkle to the challenge of getting the pacemaker "tuned" to fit our exact requirements. So, although it's reasonable to hope you will quickly feel better, think more clearly, be less tired, it may take a while and several returns to the clinic before your team can find the most optimal settings for supporting cycling. Patience and persistence might be needed to get the best performance possible from your pacemaker..

I second what others have said the need for an EP and maybe more importantly, an EP who has other patients who are young, healthy athletes. If you have to travel to find one, do it. Yes your care might take more hours, and possibly cost more, but this is not the length but the quality of your life we're talking about.

You have many years to live. And you have, and should have, higher quality of life standards. 

As you have discovered there is a wealth of knowlege and experience here, specifically among avid cyclists. The funny looking Q or maybe it's a magnifying glass in the upper right corner will let you search the archives.

Thank you!

by Ryan_CX - 2024-01-30 16:55:28

Thank you so much for your responses, this forum and the people that use it are amazing!

I'm told by my cardiologist that my initial ECG was shared widely for opinion within the NHS, so it's taken some unravelling, the prognosis is that it's a result of a lifetime of endurance training. I am confident in the care getting, I'm taking advantage of my private health insurance and had the opportunity to select the most appropriate specialist. We talked Rate Response and it's not needed to be switched on to treat my rhythm, my rate rises naturally through exercise and its rest/work that are the issue. The pacing is to ensure I maintain a normal rhythm and no longer drop into bradycardia.

It seems strange planning to be ill (for the next few weeks) but I'm looking forward to getting through the recovery,  eliminating the fatigue and getting on with my life.

Thanks to everyone that has taken the time to reply, I'm really grateful!

very athletic

by dwelch - 2024-02-17 04:28:18

I was a very athletic teen when I got my first device.  We knew for years about my CCHB before device number one.  I simply lied to my doc about my activities to avoid a lecture.  Should killed me.   Activites were in no way affected after.  Just a much better working heart, and I guess in hind sight my then oversized heart shrunk.  

By this writing you already have your device.  There will be an upper limit and hopefully you told the doc about your activities so that you may get a device with higher upper rate capabilities and or they can give you a higher upper rate.  But in theory with your heart working properly it should not have to work as hard during your activities.


Thanks dwelch

by Ryan_CX - 2024-02-22 07:36:33

Hey Dwelch, thanks for adding to this thread.

I am now almost 3 weeks post insertion and the difference in my wellbeing is night and day I thought initially that there was no improvement just warmer hands and feet, but as the weeks progress I'm starting to feel like I'm 30 again! When I think back to how I was, I couldn't walk the dog or go to the shops without getting dizzy.

I've done no cycling or running since pre-op and I'm taking careful note from my Cardiologist so won't return to cyclocross until I'm given the green light - but I can't wait!

In the end I had a Medtronic Azure XT DR MRI SureScan - Settings: DDD, 40BPM, AV Delay 250ms.

Rate response is off as my PM is being used to pick up the pauses from my heart block and ensure I don't go back into bradycardia. My settings are a slightly off, the AV delay is too short so I'm pacing more than I'd like (my PR is typically 300ms vs the 250ms setting) and the voltage is causing some nerve stimulation in certain sleep positions, but as soon as they are sorted I'll be back!

You know you're wired when...

You need to be re-booted each morning.

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