Pesistent AFIB and Accuracy Of Sports Chest Heart Rate Straps?

[MrFizz]

Hi, wondering if any other runners/cyclists that have hrm sports watches and hrm chest straps experience wide results during activities (not at rest).

Im aged 56 and have AFIB 24*7 with very minor symptoms. On 40mg Sotalol twice daily.

I have a Garmin Forerunner 245 sports watch - it measures heart rate, but I bought a ‘garmin pro’ chest strap to get close to ecg accuracy as claimed due to AFIB diagnosis.

However, during a run my watch heart rate using pulsing light on the wrist as a measure records 114 bpm, but put the chest strap on and it says 148 bpm. The run is easy, my max heart rate is 164 for my age and I felt fine as if doing nothing. I took many other readings and the chest strap ALWAYS reads >30+bpm higher during exercise.

I tried a seperate 12 year old chest strap and watch display I had, and it also over reads by the same magnitude also compared to the modern Garmin watch wrist hrm (via light pulse).

The only reasoning I can use, is AFIB is an electrical problem, so maybe the heart chest straps dont cope with heart ‘misfires’ in their algorithms, wheras the garmin watch on the wrists measures changes in blood flow as bpm - nothing ‘electrical’ about it.

Can anyone comment on their experiences?

Thanks in advance.

[Hidden]

You are correct - smartwatches and BP monitors measure the actual i.e. physical pulse whereas ECG monitors measure the electrical pulses in the heart which don't all translate into a full pumping action. They are still causing the heart to react though, so I assume they are still causing stress on the heart. I don't know if the ECG HR or the pulse HR should be taken as the max HR for exercise monitoring purposes.

[Physalis in reply to Hidden]

If you look at the ECG while it is recording on an Apple watch you will see that it is constantly changing. It can read 200 one second and 140 the next. At the end it gives an average over that 30 seconds.

[Hidden in reply to Physalis]

Is that average the same as the manual count?

[Physalis in reply to Hidden]

If it's going at an average of 140 or so, I don't think you'd be able to check your pulse manually.

Even at sinus rhythm average speed of 62 it will show, at the time you are recording it, speeds of, say, 60 to 64. There is a natural heart rate variability between beats. I am not well up on this but the greater the variability the better.

[Hidden in reply to Physalis]

Thank you

[Hidden]

I’m interested in this too and I found several posts by john-boy-92. He uses Polar kit H10 strap and Vantage monitor with an indoor rower. I’m surprised you can run with AF, you must be very fit. I don’t think there is a combination of wearable and sports monitor that is accurate in AF, and that has been my experience. btw why do you take sotalol if you are in AF 24/7?

[MrFizz in reply to Hidden]

Hi Percyflarge,

I looked at the PolarH10 chest strap too - but Im not hopeful; il look at john-boy-92 posts you mention.

Ive discovered tonight the ‘Scosche Rhythm+ 2.0 Heart Rate Sensor’ that uses pulsing green and yellow light as an arm band, and reviews say is comparibly accurate as the Polar H10 - so maybe thats the best option for AFIB ppl as its clinically accurate and doesnt use heart electric pulses that get ‘confused’ In AFIB ppl.

In answer to your question, I had cardioversion 2 weeks ago and was put immediately on Sotalol 40mg twice a day to help keep me in sinus rhythm - and whilst there my resting pulse was 52. I went back into AF on day 8 after cardioversion. I cant see the specialist for several weeks and he advised me to stay on the Sotalol. The Sotalol really works. Although my resting pulse is 64 (12 bpm higher in AF) now usually in AF, I use a cheap SPO2 finger sensor to monitor my heart pulse rhythm and its 80% ok alot of the time (see pic below) with Sotalol (and vitc, magnesium etc)

SP02 finger sensor detailing heart rhythm. Not quite symetrical rolling hills.

[Bill-G]

I am a 67 year old male in persistent afib since late 2018. I still run 3 or 4 times a week, my weekly long run 10 miles. I have found my wrist watch and chest strap hr readings to be all over the place and I now ignore them, instead I go with how I feel - am I out of breath, can I hold a conversation, do I feel dizzy etc. All the best.

[Johnboy64 in reply to Bill-G]

Hi, I’m with you regarding taking notice or not of heart monitoring. A heart nurse told me if you can hold a conversation whilst running you’re probably ok.

[Bill-G in reply to Johnboy64]

I suppose gadgets have their place but I haven’t found them reliable when I am running or exercising. So I go with how I feel, for me the hold a conversation bit is a good marker that I am not overdoing it.

[Izzle]

I had an occasion when I went into AF and was wearing a chest pulse monitor. I wanted to know how accurate it was so requested the A&E Dr do a comparison with their medical equipment. In the 140-160 range both were within just a few beats, the slight variation we put down to different algorithms in the instruments.

However on a separate occasion my chest monitor was registering in the high 40's which had never occurred before. I rung the ambulance in a panic. As my pulse slowed further right down to 42, my panic grew. Long story short, the ambo's couldn't get an accurate pulse but it was well over 100. The problem turned out to be the chest strap battery had suddenly lost it's power. Result: one very embarrassed patient.

[MrFizz in reply to Izzle]

Hi Izzle,

Better to be safe than sorry! Funny story. Thx for sharing,

[jondeanp in reply to Izzle]

I use a Polar H10 currently. A few years ago while trying to get back into running my HR was all over the place at the start of a run for about 5-10 mins even though I didn’t feel too bad. I changed the battery, but it turned out to be the actual strap that was dying. A new strap resolved the issue. Regarding the original query I had a treadmill test at the hospital. I asked if I could use my chest strap to compare readings and they were very close to the ecg readings. I can’t say by how much cos it was a number of years ago.

[Hidden]

Unless the devices have been validated by something like the FDA I would be wary of placing too much confidence in either of them. You could try taking a manual pulse when your heart is going at a normal speed, then checking with the devices to see if they give the same reading (but of course, any inaccuracies in the devices might only show up at a faster heart rate). The other possibility would be to get a Kardia which is accurate, then check its readings against the chest strap and the watch.

[Fazerboy]

I am 64 and do a lot of cycling. I managed to confirm that I had svt from my garmin hrm chest strap. Apart from also feeling suddenly exhausted etc. I bought a fitbit watch which reads hr. My iphone can also read hr. I found that when in svt the chest strap would record the high hr but the fitbit and the phone (both using light) didn’t pick it up. I also compared my garmin hrm against an ecg and they were the same. I wanted to record the electrical pulses so preferred the chest strap. I have had an ablation now so I no longer have svt. I trust the chest strap more than the light methods. I hear that Apple watches are good though but I haven’t ever had one.

[KMRobbo]

Contrary to other answers I would believe the chest strap!.I have a old Garmin 305 with chest strap. I was diagnosed afib owing to that. I was initially asymtomatic in afib except a fluttery feeling in upper chest/ neck as I went into high rate afib. I had had the fluttery feeling at the end of a run once befire and it had shown a huge spike in my hr trace while it lasted. This was about 2 months previous. ON the occasion I was diagnosed I had only got home from work at 9 pm , had the flutter feeling straight after I ate and as I was sat on my pc where the garmin was charging I put it on as i had remembered the unexplained spike. It showed 165 bpm. I felt fine but the hr remained high. I went to bed with the strap on but when I woke up I had been high rate at night so far as I could tell and was still 165 in the morning. I felt fine so was going to go to work but my wife rang 111 for advice and they sent an ambulance! I was embarrassed as I fèlt fine and suspected the Garmin was knackered. Unfortunately when the paramedics took an ECG when they arrived I actually was 165 so they took me to a&e and I was diagnosed afib. On subsequent occasions when got afib I checked the garmin and went to A&e if sustained above 130bpm. ON two occasions a&e used a finger monitor to check my hr and disagreed with the Garmin. I insisted they gave me a ECG and the Garmin was again proved generally correct. Neither my Omron bp monitor nor my wife's fitbit could count my hr when in afib. The fitbit on the occasion i used it was half the garmin rate. That is an optical check , whereas I believe the Garmin 345 chest strap checks electrical signals. My assumption was that the irregular blood flow In high rate afib confused the algorithms in the omron and fit bit. My omron actually has a flag for arrhythmia if it detects it, but the HR displayed is wrong.

[GordonEdin]

I wouldn't trust the watch to pick up uneven, fast afib heart beats. My wife had been watching her heart rate on Fitbit watch which did not show a very high heart rate. When her pulse was checked manually at the GP surgery, it was found to be reaching 150 BPM. I don't think that the optical sensors and algorithms in such devices are designed to cope with afib type situations. In principle, an electrical chest strap type sensor would seem more likely to record the fast fibrillations correctly though they might still be designed to ignite unusual signals.