Anybody with bradycardia (low heart rate)

[TLJ-1]

Shortly after multiple pulmonary emboli in April, 2022, lead to my long-term NSAID usage being stopped, tests lead to diagnosis of PMF with CALR, type 1, mutation. Along with other unpleasant health effects from that time, I have had bradycardia (binodal) very often (almost daily) with rates below 40 bpm not uncommon. One cause of bradycardia is inflammation, which is now running rampant in me due to cessation of NSAID use. However, it also occurs to me that the the CALR mutation also messes with calcium homeostasis. It seems possible to me that this could also have an effect on heart rate and pattern.

OK, so this information leads up to my question: do any of the rest of you have problems with heart rate as a possible consequence of your MPN? I would also like to hear from CALR+ people if everything has remained perfectly well with their heart. Thanks!

[Mirabellegage]

I’m CALR+, recently diagnosed (last month) PMF. RHR around 50, when I feel worse it drops down to 45 or so. I’m no athlete so no reason for it being that low. Current referral to cardio for 24 hour monitoring as I’ve had some odd stuff going on. Seemed to be very sensitive to small changes and and a higher potassium diet (noticeably stronger pounding) fortunately I picked it up on some bloods and a few days of low potassium and the strength of the pounding dropped off.

[TLJ-1 in reply to Mirabellegage]

Thanks for your response, Mirabellegage. When you see the cardiologist, please make sure you mention that you are CALR+ and that changes calcium homeostasis. Note that type 1 mutations (52-bp deletion) are more strongly affected than type 2 (5-bp insertion). The question is: does that have a possible impact on your heart rate?

[Mirabellegage in reply to TLJ-1]

Its an interesting question. There does seem that there is a role for Calreticulin in the adult heart function. I will certainly mention it to the cardiologist. pubmed.ncbi.nlm.nih.gov/234...

[Hombre]

Hi TLJ-1

It was three years ago when I had bad bradycardia and that led to investigations which in turn led to a diagnosis of ET, Calr positive. I've no idea whether the two were related. Heart investigations showed there was nothing structurally wrong. Beta blockers actually made things worse, and the diagnosis was extra beats, followed by long pauses. Now seems to be more or less ok and the ET is under control with hydroxy and aspirin.

[TLJ-1]

Thanks for sharing, Hombre. It's not surprising that a beta blocker would make the situation worse. Like you did, I get the extra beats – hence being called bigeminal (although I see that I mistakenly wrote binodal in my original post). It is great that your bradycardia disappeared and you're "more or less ok" now. The aspirin would reduce inflammation to a certain extent, although I wouldn't think it would be very much. The reduced inflammation, maybe from that aspirin or something else, could have been enough to relieve your bradycardia.