Electrical Alternans?

So I think I finally figured out what the wierd rythym I've been getting is called. I think it's a type of electrical alternan, where I have alternating RR-intervals. One slightly slower beat, then one slightly faster beat, repeat. It happens when I exercise without a very, very gradual warmup. I triggered an event on my latest holter monitor, but the report said it was just a high heart rate due to exercise. Not so I think!

I've attached a RR-interval plot of it, and an ecg image and pdf too. It is extremely obvious in the RR-interval plot, but quite subtle on the ecg, hence why it was missed in the report.

I didn't used to get this, but it only started happening over the last year. This is the time frame I started diltiazem and flecanide for afib (which I have now weaned off of). And I see studies drawing a connection between alternans and flecanide...

Does anyone have here have any experience/knowledge on alternans? Am I worrying over nothing? I've already composed an email to my cardiologist about this, but want to get some thoughts here first before potentially crying wolf. I mean, I don't have any symptoms, I just feel different and maybe not as good, I'm more worried that rhythm begest rythym and it could weaken my heart.

Maybe this means it's more important than ever to get an ablation. Or maybe I can manange it the same way I am with my afib. I really would like to wait for pulsed field ablation, but I suppose an alternan fix would require RF anyway... but perhaps from an EP with specific experience with this kind of thing...

Any input is greatly appreciated!

There is no Y scale on your RR heart rate vs. time. What is the difference in BPM from one beat to the next? Years ago, my friend who is a Wolf Parkinson White (WPW) ablatee had something like that. I slapped a Polar strap & watch on her and it seemed to be about 5 BPM variance, if my memory is correct. It did seem to materially impact her exercise output, which was annoying, but not catastrophic. Carbs in her diet seemed to make it more pronounced. She never had anything done to "fix" it. WPW folk are more prone to afib and here we are maybe 15 years post WPW ablation and she is seeing some paroxysmal afib. I also recall that a gradual warm up helped minimizing it. She's now 72.

I'll await your cardiologist's opinion but I don't see an issue. Alternans is something usually seen with fluid buildup in the pericardial sac surrounding your heart, such as cardiac tamponade or severe pericardial effusion, both of which would make you very sick and come with lots of severe symptoms. I think what you're seeing is just normal variation.

GeorgeN, thanks for always being there to give your valuable input. BBM is alternating between 115 and 125. I will see if changing carbs has any impact. Will look into WPW.

Thank you too, Carey. Most of what I've read so far about Alternans relates to alternating amplitude, and that seems to be due to the swigning heart in fluid etc., but my amplitude seems stable, it's just the RR interval that is alternating...