Slow heart rate from flecainide

[HotGuacamole]

I keep having questions and nowhere to turn. I was taking flecainide 100 mg 2x a day. Is it normal to see a heart rate of 49 or low 50s on my Fitbit when I am sitting at my desk or even driving? I don't feel dizzy or weak or anything, but I know this is from the flecainide because it is only since I re-started it April 1. I didn't see it the first time I was on flecainide at the same dose and frequency (I tried PIP for five months). I find it very weird, but it might be completely normal!

[Bagrat]

My pulse can be low 50s - 52 this am. I take 100mg bd as well. Couldnt take beta blockers as dropped lower ( I'm 80 btw). But then 98 after walking upstairs!! Don't check often but did today as feeling slightly off it.

[HotGuacamole in reply to Bagrat]

Thanks! I couldn't take beta blockers either. I feel normal, so I'm thinking it can't be too big a problem - but I'm puzzled because it is new, not something I experienced before.

[HotGuacamole in reply to Bagrat]

Considering the lack of replies, I'm guessing this is not very common.

[Gulmarrad in reply to Bagrat]

I take Sotolol 80mg twice daily and my pulse rate is 40 -45.

[KiwiBlake]

Hi. I'm on daily 100 mg Flecainide, which is for rhythm control (keeps my heart at a steady constant beat). In conjunction with this I am on a daily dose of 2.5mg Bisoprolol for rate control. It slows my heart rate down. My resting heart rate (while seated e.g watching TV) is about 48-58 bpm. Before I started taking the Bisoprolol my resting heart rate was 55-65 bpm.

That way it was explained to me is a side effect of Flecainide is that while keeping your heart rhythm steady, Flecainide can make your heart beat too fast, so it is normally prescribed with a rate control such as Bisoprolol (or other meds such as Diltiazem) to slow your heart down.

I don't feel any side effects from the lower heart rate, no dizzy sensations, I'm not lacking in energy. I feel great on it.

The important thing is that you discuss with your Doctor about any changes, so that they can tweak you meds type of dosage if need be.

Blake

[HotGuacamole in reply to KiwiBlake]

Thank you!

[Suesouth in reply to HotGuacamole]

I take 100mg x2 and it usually fluctuates between 47 - 64

[Vonnegut in reply to KiwiBlake]

Thanks for explaining the possible need for Bisoprolol but when I took the lowest dose of 1.25 it brought my heart rate down to the 40s and the EP who originally prescribed the Flecainide told me to just take the Bisoprolol if my heart rate exceeded 140 during an episode of AF which it hardly ever did.

[AAJJTt]

Hi, I am currently on 100mg of Flecainide, previously it was 150mg.

My RHR sits around 50-55bpm, dropping into the high 40s, late evening. I don’t feel dizzy or lightheaded either. I am not entirely sure, if it’s solely due to medication or a combination of factors , including meds, exercise tolerance, etc that precipitates a low HR.

Flecainide works on the sodium channels in your heart. It slows down certain electrical signals through your heart. I’ve read it slows down conductivity to the AV node but I am not certain what bearing it has on the atria and SA node ( hearts pace maker). I guess it’s conceivable.

I only have a beta blocker now as PIP. While I was on daily Bisoprolol my RHR was falling into the high 30s, which was making me listless, tired and fatigued.

[HotGuacamole in reply to AAJJTt]

Thank you!

[Vonnegut in reply to AAJJTt]

I wonder what dose of Bisoprolol you were given? I know that I am very sensitive to drugs so I persuaded the doc I saw to prescribe the lowest dose of Bisoprolol. She didn’t even arrange a follow up appointment but the pharmacist was concerned and told me to be in contact if any problems, so I did after three days of having less energy ( though much more than I have now!) and he took my pulse and told me to stop taking it as it was bringing my heart rate down dangerously low as it certainly seems to be doing with you!

[AAJJTt in reply to Vonnegut]

Hi, it was 2.5mg. As I mentioned I still can take this as part of my PIP. To date, my Afib episodes have been fast with RVR, the rate control is to help protect my ventricles.

[Vonnegut in reply to AAJJTt]

How different we all are! That dose is twice the amount that proved too much for me to take daily! But when I took Flecainide as a PIP originally I was told to take the 1.25 Bisoprolol if my heart rate was still over 140 twenty minutes after taking the 100mg of Flecainide which hardly ever happened.

[Paulbounce]

Hi HG.

When I was in sinus and on the same dose of flex as you, my HR was about the same. Personally I felt great and function at my best at those sort of rates.

Paul

[secondtry]

I am also on 200mgs and I noted it reduced my HR fro around 60 to around 55.

[PaulYeatman]

I’m on exactly the same dose as you and my HR has also drifted down. I have been on it for 4 years. Mine is around 45. On exercise - jogging - it goes up to 95-100. I too don’t have any symptoms as such. I’m not on any beta blockers either. I can’t find any reason in the literature why Flec should have this effect.?

[HotGuacamole in reply to PaulYeatman]

I can't either!

[dexter8479]

I've been on Flec for 7 years, in combination with Biso, My resting HR is low 40s, sometimes during the night it dips below 40 for a few minutes (recorded by my iwatch). Both electrophysiologists I've seen have been totally unconcerned about it. The noticeable effect it has for me is that when I start an aerobic exercise session, the first few minutes I feel more noticeably out of breath than I used to, explained to me as a Flec/bb heart has a bit of a lag before getting into the exercise zone. After a couple of minutes it disappears, and my fast cardio rate is in the 80s/90s. Occasionally over 100 when really going for it. I like to kid on that my heart is like a super athlete's 😁 - often their resting HRs can be in the low 30s I believe. Cold hands and feet is the horrible price to pay, though.

[Hidden in reply to dexter8479]

That sounds like effects of the beta blocker, which the OP isn't taking.

[dexter8479 in reply to Hidden]

My understanding of OP's question asking for others experience is that they are finding it weird to have a low HR, but was this in fact normal? I took from that that their concern is having a low HR per se. I said that according to two electrophysiologists I've consulted both have been unconcerned with low HR in itself. Other contributors who are on Flec only in this thread have responded that they also have low HR - the chap above me, as one the examples, is on Flec only with HR of 45, My EPs both also told me when I was similarly concerned about my layman's perception of a low HR, that I could come off the bb if I wanted any time, as not taking it at all would make extremely little or no difference at all to my HR.

[Hidden in reply to dexter8479]

Fair enough. I took it to be a question about Flecainide, as it's rhythm control not rate control.

[Singwell]

This doesn't help you because my HR on Flecainide tended to be higher. Hated the BBs. I did feel much better between episodes though once on theFlecainide. Looking back I suspect this was because I had untreated hypothyroidism at the time and a low resting HR, especially on the BBs. That improved and I had more energy when on the Flecainide. Now my thyroid is treated, and I only have the Flecainide for emergencies as I had an ablation 2 years ago.

[Gravel_Grinder]

I'm on the same dosage and my heart rate was 43 while eating breakfast yesterday. Felt totally fine.

[Peacockmumma]

mine is the same. Drs aren’t generally worried unless you feel unwell. ..I asked my cardiologist over the phone as she wasn’t concerned. Just look at I tn that’s it’s not wearing itself out lol

At night it will drop to 48.

As long as it’s still beating lol

[OzJames]

yes Flecainide does the same to me. Now in sinus and on 10mg of Metoprolol which is equivalent to 1mg Bisoprolol my HR drops. When in AF doctor put me on 100mg Flec then down to 50mg which got me down to mid 40 HR at rest. The Cardiologist then reduced to 25mg all drugs twice daily. I’ve taken it down to 20mg now and HR is 52-55 at rest. My normal sinus HR is 60-65 so doesn’t take much to put it into the 40’s. As a comparison in the past when I went into AF my HR was 80-90 at rest without drugs.

Also if you’re taking it daily rather than PIP I understand it takes a few weeks then your body has this constant level of the drug. With PIP it’s in and out. When I took Flecainide for 10 days prior to cardioversion it didn’t do much to HR now that I’ve been on the low dose I noticed HR change after around a month or so post CV

[Skipandted]

Hi , I’m on the same dose of flecainide and a daily bisoprolol (25mg) my resting HR is normally 45-55, I don’t feel any side effects as a result of this .

[Speed]

My understanding is that whereas Beta Blockers will reduce your resting heart rate, Flecainide has no effect on the resting heart rate but does have a gradually increasing effect as your HR rises. I have read research that shows at peak HR, the impact averages about 12%.

This fits well with my personal experience. I came of Bisoprolol (BB) as it crucified any attempt at exercise, but 50mg Flec twice a day only, has brought the max heart rate I can achieve, down significantly and even more so whenever I have needed to take Flec as a PIP.

[SuziElley]

I couldn’t take beta blockers so take Diltiazem together with Flecainide. My pulse rate is high 40s to low 50s unless I walk up a slight incline or steps.

[ChadL]

I was on Flec 100mg twice a day with Metoprolol 12.5 twice a day for 3 years, all was well then my heart rate started hanging out in the low 40's. My cardiologist lowered my Flec dose to 50mg twice with same Metoprolol dose and day and 3 weeks later my HR is in the 50-60's and sometimes high 40's while resting..

[HotGuacamole]

Thank you everyone for your replies! This is very helpful!

[Sally_Scott]

I’m on the same dose as you to keep me in rhythm. Otherwise I go into Afib. It works well for me. Resting hr 60. I’ve got a pacemaker set at 60 so if it drops lower than 60 it kicks in. When I’m doing exercise it can go 80-110.

[wwatson280283]

Hi there, I was on 50mg Flecainide bid until recently. I too had a HR which was occasionally falling to the mid to high 40's when sitting watching TV in the evening. When I say occasionally it was once every few weeks. I would feel as if my heart had stopped for a split second and I was going to faint. I went to my cardiologist who mentioned that it could be Tachy-brady syndrome. Identified as bradycardia alternating with paroxysmal supraventricular arrhythmias, most frequently atrial fibrillation (AF). I was put on a monitor for two weeks and sods law I didn't have a similar episode during that period. I did have an episode of AF where my HR was 240. I was subsequently prescribed 100mg Flecainide bid.

I too have a suspicion that the occasional very low HR I experience is down to the medication. Unfortunately without the hard evidence presented by the monitor the cardiologist was more concerned with the high HR. I would assume that you like me are concerned with the low HR because you can't manage the episode if you have fainted but can when the HR is high.

I am 57 and now contemplating the ablation route as mentioned by my cardiologist to try and bring this terrible condition to an end.

[HotGuacamole in reply to wwatson280283]

Yes, I was on the 100 mg 2x a day for about a month before it started trending down. I guess it was the change that made me uncomfortable - the way it was trending, it made me wonder how low it would go. I saw my cardiologist this week and he said I could try another trial of a pill-in-the-pocket. I hope it will work for me this time.

[WildIris]

My pulse is in the low 50s, sometimes 49 on 12.5 mg metoprolol (half a normal dose). I feel fine.

[Mcopt]

I am on the same 100mg bd, do you take a beta blocker like bisoprolol as well ? My heart rate has always been slow resting can be low 40s , it is still like that and I have to be careful not to take a high dose bisoprolol I only take 1.25mg once a day the lowest dose.

Flecainide is a rhythm control med and shouldn't affect rate whereas a beta blocker will affect the rate in most people.

Perhaps speak to your doctor but for most resting rate of around 50 shouldn't be a problem.

[Quest4NSR]

You checked Blood Pressure? All normal?

[HotGuacamole in reply to Quest4NSR]

All normal.

[Quest4NSR]

Heart probably adjusting then, mine did that when I first was on it for a couple of weeks

[bigtallgeezer]

Hi, I’m on the 100mg maintenance dose of Amiodarone after about 18 months in and out of Afib with other drug treatments. Before Afib I was a fit late 60’s chap doing two and half hour gym sessions 4 times a week.

My resting pulse at that time was mid 40’s.

Now, my resting pulse is always around the mid 30’s and drops to low 30’s several times a day, usually 31 at present. It has been as low as 29.

Obvioulsy, that is too low and makes me feel barely alive, and very breathless. It appears there are no drugs to lift a pulse rate at rest, and I am waiting for a sometime/never UK NHS pace maker and ablation.

I can make my pulse go higher by pottering at various things around my house including gardening, and have even gone back to my gym recently for vastly decreased gentle exercise including walking, working on the theory that if I go ‘man down’ it will be noticed by someone to help me, where that might not be the case if I was doing that outdoors.

Good luck!

[HotGuacamole in reply to bigtallgeezer]

Oh wow - that's concerning. If you get the ablation maybe you won't need the pacemaker?

[bigtallgeezer in reply to HotGuacamole]

Time will tell I guess….The waiting time for an op. if you can ever see a EP in UK is long, somewhere between 18 months and 200 years!

I wish I’d had a heart attack instead of this, at least you stand half a chance of getting fixed.

[HotGuacamole in reply to bigtallgeezer]

Oh, I'm so sorry. I guess I'm lucky on this since I am in the U.S.

[wilmo12]

Hi

Diagnosed with AF in 2016 and took Flecainide 100g, 2.5 mg of Nebivolo and Xarelto until an ablation in 2018. It was a successful procedure. However, my cardiologist did not change the medication even though my AF was gone. As my blood pressure was high, I was prescribed with indapamide instead of my usual Telmisartan. Couldn't remember for how long, maybe two months or so, my heart rate went really low for days and I fell light headed. I Googled and found that there's interaction between Flecainide and Indapamide. So I decided to stop taking Flecainide as I couldn't get in touch with my cardiologist until my appointment the following week. Anyway after seeing him and he agreed to stop taking it and I have not taken any since.

Better check with your doctor, maybe once a day is enough as your rate is too slow

[sarniacherie]

Beta blockers lower the heart rate and over the years I have been prescribed several different ones until a 48 hour tape returned readings of 33bpm. The cardiologist decided that beta-blockers are not for me so stopped me from taking them. I found Flecainide suited me but when my 70th birthday was coming up he took me off them, yet I often read posts on here of older people still taking them. Sotalol and Bisoprolol were the worst ones for me. I would mention your concerns to your medics.

[Poppyred1]

My normal resting heart rate is low to mid 50's. Apparently it's fine as long as you feel okay ie no fatigue or light headedness