Flecanide/ heart failure / QRS

I just had ablation touch up (6/2) to get at 2 areas of flutter and a slight touch up of the fib area they did on 2/25. Before I was on dofetilide and I was on that until a couple weeks before the 2nd ablation. They were going to put me on amnioderone and so I stopped the dofetilide in prepretation for that. Then I had an appt with EP and I cried (literally) and the EP put on his schedule for ablation in 10 days out instead of the amnioderone. So... after the ablation they put me on flecanide for the blanking period. I have had problems with beta blockers in the past.

So first, QRS. When I left the hosptial, my QRS was 105. They wanted me to repeat the ECG in a week which I did, and the QRS was 120 which was the upper limit from my google searching. I am going another one on Tuesday. But what exactly does this 'mean' and how might it look in symptoms if anything? What kind of questions do I need to be asking.I know the flec can increase it...

Also- I have a complicated history (congential/ 5 open heart surgeries).. Several years ago when I went on metropolol my BNP (blood test measurement-ish for heart failure) was very high and so they said I had "heart failure" .. never mind that when I went off the metropolol, it went back down. My latest BNP was 70 with is very very normal. My ejection fraction is normal. BUT I feel now on the flec like I did on the metropolol. I take extra lasix right now from time to time. And in my googling I did read that people with "heart failure" shouldn't take flec. My congenital doc was aware of this but said it would be OK during the blanking period. Basically I blow up like a balloon.. and it isn't like being short of breath- it is more like the pushing action from my stomach makes it hard for my heart to work. I have been in touch with all the docs on this of course. Not looking for medical advice. Just wondering if others have had this experience. I wish I had not stopped the dofetilide because I would have been happy to stay on that during this period but it is a 3 day hosptial stay and even on that I ended up at the lowest amount because of my QT internal.

Mostly would like to know what questions I should be asking... also I think I might have run the gamut of antiarrhytmics that aren't beta blockers. What others are not beta blockers I might suggest other than flec and dofetilide. Of course they should be offering them to me LOL. but I want to have my ducks in a row. (Ps.. I'm only 55... and my guess is although I have afib triggers, my surgeries are probably what started the whole ball of wax). Also anyone else have these sorts of side effects from the flec?

ps I have had some periods of a few min of whacky beats but no real afib since the ablation.. so it might be working which is why I don't want to toss it...

Thanks



Edited 3 time(s). Last edit at 06/19/2022 09:47AM by bettylou4488.

What is your dose do Flecainide and do you know if you might be a poor metabolizer of CYP2D6, the pathway that Flecainide primarily uses? I ask because if you are a poor metabolizer of that pathway, your dose of Flecainide needs to be lower than ‘normal’ as it can build up in your bloodstream. I learned this the hard way when I started getting ‘wide QRS’ on my Kardia and then it progressed to heart block. This happened after a dose increase of Flecainide. Sorry, I don’t know how high the QRS was as Kardia doesn’t tell you. When I asked my new cardiologist whether he had seen this with Flecainide he said yes and that was a typical pattern—wide QRS leading to heart block. But, I AM a poor metabolizer of CYP2D6 so it is likely that this led to an ‘overdose’ though I was within the normal prescribing range.

Quote
Daisy
What is your dose do Flecainide and do you know if you might be a poor metabolizer of CYP2D6, the pathway that Flecainide primarily uses? I ask because if you are a poor metabolizer of that pathway, your dose of Flecainide needs to be lower than ‘normal’ as it can build up in your bloodstream. I learned this the hard way when I started getting ‘wide QRS’ on my Kardia and then it progressed to heart block. This happened after a dose increase of Flecainide. Sorry, I don’t know how high the QRS was as Kardia doesn’t tell you. When I asked my new cardiologist whether he had seen this with Flecainide he said yes and that was a typical pattern—wide QRS leading to heart block. But, I AM a poor metabolizer of CYP2D6 so it is likely that this led to an ‘overdose’ though I was within the normal prescribing range.

im only on 50 am and pm. I don't know if I am a poor metabolizer of CYP2D6. I am familiar with what you are talking about because of head meds for our son but how do you KNOW if you are? what testing? I guess we shall see what the ECG says... what is "heart block" exactly and is it reversible? I really should know the answer to that but I don't.

thanks

The next obvious choice for you to try is Multaq (dronedarone).

Quote
bettylou4488

im only on 50 am and pm. I don't know if I am a poor metabolizer of CYP2D6. I am familiar with what you are talking about because of head meds for our son but how do you KNOW if you are? what testing? I guess we shall see what the ECG says... what is "heart block" exactly and is it reversible? I really should know the answer to that but I don't.

thanks

50 mg is a low dose, as I’m sure you know. My EP did pharmacogenetics testing. Heart block is when the beat in the atria is blocked from reaching the ventricles, (there are degrees of heart block) so basically your functional heartbeat is blocked either partially or completely. Thankfully I already had a pacemaker. Yes, heart block is can usually be reversed, at least that is how I understand it. As Carey mentioned, Multaq could be an alternative— that is what I am taking now.

Quote
Carey
The next obvious choice for you to try is Multaq (dronedarone).

But that has a beta blocker in it yes? not sure how I would tolerate it..

Quote
bettylou4488
im only on 50 am and pm. I don't know if I am a poor metabolizer of CYP2D6. I am familiar with what you are talking about because of head meds for our son but how do you KNOW if you are? what testing?

[www.labcorp.com].


The xTAG® CYP2D6 Kit v3 is a qualitative genotyping assay, which can be used as an aid to clinicians in determining therapeutic stategy for therapeutics that are metabolized by the CYP2D6 gene product. CYP2D6 is involved in the metabolism of more than 65 commonly used drugs including β-blockers, antipsychotics, antidepressants, analgesics, and antiarrythmics. The CYP2D6 gene is highly polymorphic. Many alleles of 2D6 encode enzymes that have reduced or no function compared to the wild-type enzyme. Individuals can also have gene rearrangements with more than two copies of the CYP2D6 gene (gene duplication) or absence of both copies (gene deletion). Depending on the combination of alleles in an individual, drug-metabolizing phenotypes associated with the CYP2D6 enzyme can vary.

Quote
bettylou4488
But that has a beta blocker in it yes? not sure how I would tolerate it..

No, it does not. It will lower your heart rate some, as most antiarrhythmics do, but that's not because of any beta blockers. Multaq contains nothing but dronedarone, which is in the same class of antiarrhythmics as dofetilide and amiodarone. But it's "milder" than those and has fewer side effects. It's the next logical choice (and there aren't many more).



Edited 1 time(s). Last edit at 06/19/2022 04:47PM by Carey.

Quote
Carey

But that has a beta blocker in it yes? not sure how I would tolerate it..

No, it does not. It will lower your heart rate some, as most antiarrhythmics do, but that's not because of any beta blockers. Multaq contains nothing but dronedarone, which is in the same class of antiarrhythmics as dofetilide and amiodarone. But t's "milder" than those with fewer side effects. It's the next logical choice (and there aren't many more).

Thanks.. based on how this week goes I will bring it up. There was a reason when I spoke with the cardiac pharmacist that they weren't using it before. I am only 2 weeks out from the ablation- and the doc told me to keep taking it EZ. (That is not my natural bent! LOL!)

Quote
GeorgeN



[www.labcorp.com].

.

thanks!

Quote
Carey

But that has a beta blocker in it yes? not sure how I would tolerate it..

No, it does not. It will lower your heart rate some, as most antiarrhythmics do, but that's not because of any beta blockers. Multaq contains nothing but dronedarone, which is in the same class of antiarrhythmics as dofetilide and amiodarone. But it's "milder" than those and has fewer side effects. It's the next logical choice (and there aren't many more).

Maybe I’m unique but once I started multaq I had to stop Tenormin—which was rough because I was on Tenormin since 1987 and didn’t properly wean off. I was told by two EPs that it isn’t a BB but can act like one.

Sotalol (200mg/day) lowers my hr so much my pacemaker, set at 55, is pacing 98.4%. Technically it’s an anti arrhythmia drug but also affects one’s HR. Well…at least for some.

Susan, Tenormin is a brand name for atenolol, which is a beta blocker. Sotalol is also a beta blocker.

Got my ECG.. QRS went up.. sigh. thankfully BNP was well in normal. Potassium / Mg all normal. Will see what the docs say. QRS was at 105 on 6/2 when left hosptial, 120 a week later and 130 a week and half later. that is what is written on the EKG. I don't know if they hand calculate like they do with the QT. But in sinus.. so that's super. I will bring up Multaq if I have to go off it.

Quote
bettylou4488
that is what is written on the EKG. I don't know if they hand calculate like they do with the QT. But in sinus.. so that's super.

I don't know why anyone would hand calculate either number when the EKG machine does it for you with perfect accuracy. The numbers you see on the EKG are the numbers you have.

Quote
Carey

that is what is written on the EKG. I don't know if they hand calculate like they do with the QT. But in sinus.. so that's super.

I don't know why anyone would hand calculate either number when the EKG machine does it for you with perfect accuracy. The numbers you see on the EKG are the numbers you have.

I am not sure but it is a thing. When I went on dofetilide they would do the EKG and they would come in and hand calculate. each time. I did say I wanted them to ask the actual DOCTOR. (It was the NP or PA that read it). And I will contact my congenital doc .. he is on vacation this week but the other one on the team is there. I always get the straight scoop from him. He wasn't thrilled with me being on flecanide but said it was OK for the blanking period. I have heard of this hand calculating thing though and so I wonder.. maybe mine is a whack-a-doodle. My ECG has said abnormal as long as I remember so they compare it to older ones. Even at the ER .. "it's abnormal but normal for you." Either way.. I need clarification but if anyone still reading this thread knows why they'd hand calculate please pipe in. thanks.

The EKG saying "abnormal" is a bunch of noise you can safely ignore. Nobody -- and I mean nobody -- pays attention to the diagnostics EKG machines spew out. But their measurement of things like QRS duration and QTc are 100% accurate. A human cannot possibly be more accurate, so all I can imagine is that your docs are applying some sort of unique formula to you due to your other conditions.

Quote
bettylou4488
Also- I have a complicated history (congential/ 5 open heart surgeries).. Several years ago when I went on metropolol my BNP (blood test measurement-ish for heart failure) was very high and so they said I had "heart failure" .. never mind that when I went off the metropolol, it went back down. My latest BNP was 70 with is very very normal. My ejection fraction is normal. BUT I feel now on the flec like I did on the metropolol. I take extra lasix right now from time to time.

This sucks:
[www.medpagetoday.com]

Quote
Carey
The EKG saying "abnormal" is a bunch of noise you can safely ignore. Nobody -- and I mean nobody -- pays attention to the diagnostics EKG machines spew out. But their measurement of things like QRS duration and QTc are 100% accurate. A human cannot possibly be more accurate, so all I can imagine is that your docs are applying some sort of unique formula to you due to your other conditions.

The doc looked at it. I'm going to just roll with what they are saying. Had a rapid(er) heart rate last night and then an afib episode .. most seems digestion related. I may write another post on that later. I wonder if what I have been feeling lately isn't a function issue but was afib. I just was trying to relax and not hyper analyze so I didn't do any cardias.. But did a couple Kardia last night... Anyway.. I either trust them or I don't eh? And I will check in with my congenital doc when he gets back from vacation next week. I'm also doing more than I did 3 weeks after my first one which I thought was good but I'm going to simmer down some and chill more.