Fluctuating heart rate. : Can anyone else on... - AF Association

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Fluctuating heart rate.

ETHEL103 profile image

Can anyone else on here tell me if your heart rate fluctuates wildly during a fib. Goes down to 40 then 60 then 50 ect.?

39 Replies

Mine does as well anything from 120 to 80 then occasionally down to 35. I had a CT . angiogram today and was mesmerized by the constantly changing heart rates whilst attached to the EGG machine. I am having AF . all the time at the moment.

ETHEL103 profile image
ETHEL103 in reply to Louisep1958

Me too. Horrible isn't it?

RaraAvis profile image
RaraAvis in reply to ETHEL103

If the symptoms are so bad is it not the reason to use flecanaide?

ETHEL103 profile image
ETHEL103 in reply to RaraAvis

I haven't seen a cardio or EP yet. On a waiting list for a call.

Yes, absolutely, that's the nature of the beast ! Mine can go from 70s to 240 and beyond, all over the place! It frightens the life out of me at this rate even though I should be used to it by now. Also I don't care how many people say that 'it can't kill you...' all I know is that it b....y well feels like it !!


ETHEL103 profile image
ETHEL103 in reply to Jalia

Mine is going really low to ight. Down to 35 then back to 60..Feel a bit woozy when it goes down.

baba profile image
baba in reply to ETHEL103

You need to see a doctor. Next step from heart rates that low is loss of consciousness - no fun.

Glb1948 profile image
Glb1948 in reply to ETHEL103

Mine has been doing that today. I was going to ask the same question as mine has been from 44 to58 and back to 51. I was feeling light headed too and had to lie down.

Caradomben profile image
Caradomben in reply to ETHEL103

Mine does that too. Scary when it goes down to 35 . Never seems to go above 50 when resting .

ETHEL103 profile image
ETHEL103 in reply to Caradomben

Hi are you on meds at all?

Caradomben profile image
Caradomben in reply to ETHEL103

Yeah I am on Flecainide 100mgs twice daily and 1.25 mgs bisoprolol . Not sure if it’s the bisoprolol I don’t tolerate .. was on 2.5mg but reduced it about 2 month ago but no difference. Got an appointment next month with cardiologist .

I was having the same issues going down to 35 up to 140 back down to 35 etc ,,,now have pacemaker ,best thing I ever got done it’s stopped me feeling faint and light headed ,,

Treschere profile image
Treschere in reply to Jalia

Jalia you need to see someone if it goes that high (240) go to A and E

Jalia profile image
Jalia in reply to Treschere

Thank you Treschere. I do go to AE when that high, if by myself it's been a 999 call.

Jalia wrote

"Mine can go from 70s to 240 and beyond"

240 is a red light job Jalia. There and then.

Ethel wrote

"Can anyone else on here tell me if your heart rate fluctuates wildly during a fib"

Yep - it's like a yo yo. An instant drop like that will certainly make you feel woozy. If you feel it coming on make sure you sit down. A sudden drop like that can make you feel very poorly for a few minutes or more. Your rate is nearly halving - if this happens quickly it can really hit you. Make sure you sit / lie down if you feel this happening.


Jalia profile image
Jalia in reply to Paulbounce

Don't worry Paul , 240 has almost always meant a paramedic call out when it doesn't subside. Hence my tally of 20+ dccvs

( 4th ablation in 2 weeks..)

If I eat during AF the heart rate often increases considerably.

Obvious but crucial questions: what are you using to measure your heart rate with and how long is the segment it's measuring?

CDreamer profile image
CDreamer in reply to HiloHairy

Excellent comment as finger monitors, BP machines and pulse monitors will be inaccurate.

LaceyLady profile image
LaceyLady in reply to CDreamer

My ORMRON X7 takes 3 blood pressure readings

momist profile image
momist in reply to LaceyLady

Clever machine, but it's still measuring the rise in blood pressure during a heart beat. When in AF, some heart beats occur so much at the wrong time that the heart hasn't filled with blood, and there is no rise in pressure to measure . . .

The only valid record of heart rate in AF is from the electrical signals generated by the heart.

LaceyLady profile image
LaceyLady in reply to momist

When I had my partial knee replacement 11/2019 the nurses weren’t taking my BP properly, using too smaller cuffs! I said to one because it was coming off, carried on taking it 😡 I’ve been a Complementary Therapist for 23 years. Yes I did make a complaint to the matron.

ETHEL103 profile image
ETHEL103 in reply to HiloHairy

Finger monitor and fit bit. Take BP a couple of times a week. It shows arrhythmia if HR is all over the place.

Whatever device you are using to record your bpm it's important to consider how the result you see is calculated. For a genuine "beats per minute" result the device would need to count the number of beats in the previous 60 seconds and display the cumulative total as the current bpm. However that would not be the current bpm but the average over the previous 60 seconds. Many devices simply record the interval between the last beat and the one before and then extrapolate that to a bpm. In AFib your heart may be beating in an irregularly irregular manner so the time interval between beats is not constant but varying widely. Two quick beats might compute to a heartrate displayed as 220 bpm whereas the next beat comes a bit later so the device computes this as 120 bpm. What is displayed on your device may not be actually beats per minute but a computation based on the time interval between two consecutive beats.

Excellent description

Great information 👌

Yes, it happens to me all the time, but it never goes over 90. I think 🤔 it is because I'm on Digoxin and Flecainide.

Ethel when I had Paroxysmal Afib used to go from 50bpm to 125bpm and then spontaneously return to my then norm of 50. Went into perm Afib and since then had 2 ablations. My very best to you.

ETHEL103 profile image
ETHEL103 in reply to Smileyian


Hi ETHEL103,If your heart rate goes down to 40bpm constantly then that is into bradycardia ( Heart rate too low) That is ambulance time. Unfortunately af is a shifting heart rate from any parameter in any parameters. A horrible scourge. I am now af free after a successful ablation on 5th November 2019 but can sympathise with anyone with it.

Good luck for the future and hang on in there.

Best wishes


My heart rate goes up to anything between 150 to 240 and then drops down to nothing and pauses for a few seconds and l blackout. After a few minutes it does it all over again. It keeps doing that until go back into normal sinus rhythm.

Omg that's awful for you.

I think the consultant is going to suggest pace and ablate which is a last resort. I am not too happy about that as your life depends on a machine to keep your heart going and we all know that machines can break down. The trouble is high doses of drugs make me very ill, so l am in a bit of a quandary. Thank you for your concern x

Yup. Has gone between 50 and 160 and at worst, around 250 (rare, thankfully) Its the nature of the beast, sadly.

Mine goes all over the place and hard to document.

Yes mine fluctuates I think this is the exact nature of afib an irregular heartbeat

Thats not bad fluctuations. Go walking if possible. Avoid strong coffee i have weak tea. Plenty water. No late nights. Dont look at computer or tv screens at least 2 hrs before bed.

I would think that if one has a HB of 100 and the left ventricle fails to produce any pressure due to it being empty every second beat then the reading would be 50 bpm during this anomaly.

The actual beats will still be 100 but the instrument would read 50.

I think Sheepbreeder's post nails this. HR monitors are not designed to measure a fluctuating rhythm, so the numbers they are displaying are meaningless to someone in AF. Let's imagine there are 3 very quick beats followed by two with large gaps between. Quite typical of AF, I'm sure we'd all agree. The monitor may register 200 then 25.

To someone in sinus rhythm this would be a swing requiring medical intervention, but not so with AF.

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