Chest Pain post intense workouts (HIS Bundle Pacer)

Hello from Oregon!

I'm about 18 months out from HIS Bundle implant for complete AV block. I believe I am the only HIS Bundle patient in this extremely large practice. 

Twice with high intensity workouts, where I pop up to my 170 cap, I experience 3-4 hours of mild tachycardia 95-105 followed by over 48 hours of chest pain and fatigue.

All lab work normal - thus no heart attack. 

Anyone else experience similar phenomena?

Cardiologist states the clean blood work suggests that it cannot be cardiac. I'm not so sure based on its presentation, but unsure what else to suggest to consider in the differential.


Thank you,




Chest pain

by Gemita - 2020-10-10 03:10:24

Shana until you get some answers I would avoid pushing so hard.  48 hours of chest pain and fatigue sounds concerning and needs investigating.  

I can get chest pain from gastric (oesophageal) and bone problems, as well as from poor blood flow during an arrhythmia.  My arrhythmia can cause fatigue for hours, or even for several days but the chest pain from an arrhythmia usually subsides fairly quickly once the arrhythmia stops.

I note you get mild tachycardia for several hours prior to experiencing chest pain/fatigue for up to 48 hours.  I would respectfully ask perhaps for an exercise induced stress test to look again for any signs of coronary artery disease, arrhythmias, inadequate blood flow, valve problems, ischaemia as well as looking for an alternative diagnosis.

Do you have access to a rapid access chest pain clinic which you can attend when this next happens?  Try to catch the problem when it is actually occurring, or ask for longer term monitoring.  Very strange because of chest pain "duration" which doesn't seem to fit with a cardiac diagnosis like angina/ACS (acute coronary syndrome) although I may be mistaken.  

Does chest pain occur when you don't exercise or have you noticed this type of chest pain at other times?  Is your long lasting chest pain always preceded by mild tachycardia symptoms?  Costochondritis is a frequent cause of long lasting, non cardiac chest pain.  Did they check for any infection, inflammation, joint problems?  Try to keep diary notes of what brings it on (?in addition to high intensity work outs) to help with a diagnosis.  

Is your pacemaker working properly and able to sustain high intensity work outs?   Do your settings need adjusting ?  Maybe a visit to your pacemaker clinic for a few checks is also warranted although this type of problem should be picked up by a stress exercise test.  What a mystery, good luck and please let us know how things go.

Thanks Gemita!

by Shana - 2020-10-10 12:45:04


Thank you for your well thought out response and for caring.

I appreciate your brainstorm of non-cardiac chest pain sources. I'll research them.

We've completed a treadmill  stress test at similar exercise intensity and it looked great! We have opted out of the more invasive angiogram based on my heart's performance and other risk factors - my risk for CAD is less than 1%. 

I rarely push to my cap with exercise  intensity - which is good news and plan to keep it that way. The two times this has happened were 4 months a part.

Good point about the tachycardia triggering the fatigue. I forgot about that! I've have had similar tachycardia/fatigue patterns that weren't exercise induced. 

This is my analogy of what it feels like- a strained muscle. When you strain a hamstring on an intense training session by pushing it hard, it hurts for a period of time after the workout. Could be days/could be longer. The heart is also a muscle, right? After I push it to the cap, when Wenkebach kicks in, it hurts. And continues for a few days.  If the heart wasn't so integral to our well being and didn't have the complicated electrical system, would it be possible to make the analogy  to a strained muscle? Totally over simplifying, I know.


You are probably right

by Gemita - 2020-10-10 14:34:11

Shana, I would agree, a serious cardiac cause for your occasional, long lasting intense chest pain seems highly unlikely !  The likely problem seems to point to a muscle strain, pull or tear but which muscle ?? 

From your description you are definitely not arrhythmia (tachycardia) free either and with an arrhythmia, if you try to push through it (as I well know) it can cause troublesome symptoms.  It could be that when you were exercising you also had atrial tachycardia occurring in the background, albeit only at a lowish rate, which made your heart work even harder to sustain your vigorous work out.  As your heart rate rose, it might have placed an extra strain on your heart muscle. 

Have you had an echocardiogram recently done to have a look at the size of your heart chambers?  Some athletes do develop enlarged heart chambers - and arrhythmias - as a result of intense exercise.  I am not suggesting you stop exercising, just be aware that arrhythmias, like AF (Atrial Fibrillation) or Tachycardia (SVT, AT) can suddenly start when we push ourselves to our limits.  When you get symptoms again, try to record your heart rate/ECG to see what is happening or do a pacemaker download for your clinic, giving them the time and date of any symptoms.  Do you have a Kardia Mobile or any other good home monitor?  Great way to take the evidence to your doctors.

You clearly had fatigue symptoms after your vigorous exercise.  Do you ever get any breathlessness, dizzy spells to accompany your fatigue and chest pain?  When I get a fast arrhythmia my chest pain, breathlessness, instability can be quite worrying and I have had to attend ER/A&E too on occasions because of my concerns.  I have other health conditions, so I am very prone to joint pain in the chest region, so this can complicate the picture for me too.

I feel though if you had placed too much stress on your heart during your vigorous work outs, your situation might be more concerning now.  You would not, I think, after say two days or so of chest pain just get over it.  There would probably be some noticeable residual symptoms perhaps to show that you had exceeded the safe limit of your cardiac output.  

I would be inclined to think that you suffered from musculoskeletal chest pain/fatigue (possibly intercostal/chest wall muscles) complicated by an arrhythmia during your intense work outs?  Maybe a chest X-ray would help rule out any other problems like a potential small fracture somewhere, or you could visit a musculoskeletal therapist?  Monitoring your heart and keeping a diary when you next get fatigue symptoms will also help to learn more, as well as getting an echocardiogram done to look at your heart chambers, valves, ejection fraction.  I would also want to know what your pacemaker settings are and whether these are appropriate for your lifestyle.  I would also ask your doctor whether your heart condition/block has progressed in any way to cause occasional fatigue and chest pain on exercise?   Good luck

Just a WAG

by AgentX86 - 2020-10-10 20:19:10

Is it possible that when you hit your maximum, your pacemaker shifts into VVI mode and you lose synchrony?  Your heart will suddenly become much less efficient and perhaps you're starving it of oxygen.  This would be a circuitous route to angina and something not easily detectable.

Progression & VVI

by Shana - 2020-10-14 10:33:33

Good morning!

Gemita, I have had an echo in the last year. All good. I think it will be a watch and wait - continue to report symptoms. It's clear my cardiologist has no interest in further assessment. I may go back to my internist to assure she feels just as confident. 

AgentX, I believe I know what you are describing with VVI. Although, my team describes it as Wenkebach.

From 165-170, enters an asynchronous rhythm and then once I hit the cap at 170 it moves to a 3:1 rhythm. It's crazy to be running stairs and watch my heart rate drop so quickly. Obviously, I am forced to stop for oxygen. 

I totally agree about long lasting discomfort when this happens. In the more recent occurrence, however, I caught it manually for just a second. Then back to normal. It wasn't a complete 'hit a wall' experience. 

Regardless, I do believe the intensity of this workout definitely played a role in my chest pain.  I've made adjustments to my training to try and avoid this. First time since May is pretty good! 

Thank you both,



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