Kardiamobile says sinus rhythm but Galaxy watch says AFib

[easygoer13]

Just wondering if anyone's had this experience I have both the Kardia mobile and a Samsung smartwatch Samsung says afib but kardiamobile normal. heart rate in the 70s does anyone know one could be trusted more than the other

[Ppiman]

I would doubt neither can be fully trusted as both use only fingers / wrists to pick up the changes in the heart's electrical output. I have had my Kardia report AF twice while my Apple Watch gave NSR on the same occasions but I imagine either could be wrong at times. What I was having, a cardiologist told me, was frequent ectopic beats which the Kardia mistook for AF. I think the detection system, using fingers rather than electrodes is the likely weakness.

I have recently changed to a Wellue AI monitor, which can use either fingers or other parts of the body, but also can use ECG electrodes and it's pretty clear that the cause is finger measurement which is far "noisier" than using the electrodes. The algorithm used by Apple and Kardia must do a lot of smoothing of the noise, but this doesn't make the measurement more accurate, of course.

On the graph, look for the tiny blip before the big spike. It can be hard to see. This is the "P" wave which represents the atrial contraction in NSR. In AF, there can be no single P wave at all.

I attach an Apple ECG from my watch that shows the multiple ectopic beats and I've added in the PQRST points on the trace.

Steve

Apple Watch ECG showing ectopic beats and PQRST points.

[easygoer13 in reply to Ppiman]

Thank you and hopefully people can see this the other folks who have replied as well. I'm not sure how to read the ekg but I was seeing what I thought were p waves on both and I think it was probably a little bit of I don't even know what they're called but for me when I'm resting watching TV or what not my heart rate is usually in the 50s and 60s and at this time it was in the 70s so was little higher and I had been pretty active doing some chores around the house which I think spurred it on. I had a little bit of a rough beat but I knew I was good when I laid down and it drops to the fifties

I had an ablation 4 years ago and I've been good since I've had a couple of maybe quick turnaround bouts where I may gone into I'm not even really really sure but other than that I've been very solid and consistent

[Ppiman in reply to easygoer13]

Yes - if there's a P wave, then you are experiencing palpitations rather than AF, I would think.

Steve

[CDreamer]

I’d go more with the Kardia results than the watch but neither will be infallible. Could just be timing?

[Buzby62]

I don’t have either but I have Apple Watch which I believe is the same technology as the Samsung. There is a difference in accuracy depending whether you’re using the electrodes with your finger or just the background checks from the optical sensor on the back. The optical sensor only suggests there may be AF from the heart rate variability seen in the blood through the skin and is susceptible to errors. The electrical sensors are more reliable as it is looking for absence of the p wave in the trace as Steve mentions.

Are you seeing AF electrically on the watch?

[Thomas45]

I'd go with how you feel, instead of analysing what a gadget tells you.

[Ppiman in reply to Thomas45]

Sage advice. Or at least, worry (if that's what you might end up doing) because of the feelings before the watch / Kardia / Wellue before testing, rather than any feelings after testing.

[1969hippy]

Don't have either of these devices. Would you recommend them?

[Ppiman in reply to 1969hippy]

The Wellue is unique if you suffer other arrhythmias than AF and struggle to record them as they are fleeting. It is excellent but the Apple Watch is so much more useful in other, unrelated, ways.

Steve

[Rainfern in reply to 1969hippy]

Iwatch has at least 148 Snoopy animations on one of its faces and keeps a check on sleep patterns. These things alone cheer me up! But I only bought it cos recommended by my EP and it has been useful for getting the general picture which is really all you need with persistent AF.

[ochinee]

"Don't have either of these devices. Would you recommend them?"

I have the 6 lead Kardia and comparing it with the MD office EKG it's very close.

[Ppiman in reply to ochinee]

I think the Kardia is very good indeed but isn't the comparison with a twelve lead medical ECG only valid in recognising the pulse irregularity and the lack of a P wave? Other than that, isn't the Kardia "six lead" only its (very clever and expensively produced...) algorithm interpolating those extra "views" of the heart's electrical activity (well, I guess it does). Also, and more pertinent, the electrical contact remains insecure and very "noisy" as it is by touch rather than by gel/electrode?

EDIT: I had forgotten the Kardia has a third rear electrode which provides the "six leads". The contact system remains by simple touch, rather than gel electrodes, so the noise issue will still remain and need artificial smoothing via the app's algorithms; also the maximum 5 minute duration remains.

Steve

[ochinee in reply to Ppiman]

Below is the "Conclusion" of a 2021 study of 1,025 individuals using the Kardia 6 lead and a 12 lead EKG published in the European Health Journal.

My cardiology PA said it's easier/faster to read the Kardia to confirm sinus rhythm than the 12 lead EKG for whatever that's worth.

"Conclusion

Several parameters recorded by the Kardia 6L (QT interval in all six leads, rhythm detection, PR interval, QRS duration, and cardiac axis) perform closely to the gold standard 12-lead ECG. However, that consistency weakens for left ventricular hypertrophy, QRS amplitudes (Lead I and AVL), and ischaemic changes."

[Ppiman in reply to ochinee]

Thanks for that. I am sure confirmation of NSR is good on all of these home devices. The Kardia is a very well made and nice looking device; the Apple Watch offers so much else that is useful, but at a higher price, including various long term measurement if needed. The near £10.00 extra cost each month for "Kardia Advanced Determinations" eventually moved me to buy the two Wellue AI devices as I get more palpitations than AF. The Wellue's ability to carry out AI measurements for up to 24 hours using chest electrodes is unique for a home device and incredibly useful to prepare for a cardiologist consultation.

Steve

[ozziebob in reply to Ppiman]

Your Wellue device is still a single lead reading, compared to the 6 leads of the Kardia 6L.

Are you saying the extra diagnostic information contained in the 6 lead ECGs are of no value to medics who are trained in ECG interpretation? Surely not!

Then again, I don't think the Wellue device is medically approved in either UK or USA.

[Ppiman in reply to ozziebob]

Yes, you are right, Bob, thank you. I had completely forgotten that third electrode and have added an edit to my post above.

The noise issue remains a weakness, however, I feel sure and that needs to be smoothed artificially and so produces a less detailed trace than one using electrodes. Also, the Kardia app's determinations, I think I read somewhere, are all derived from the single lead and 30 seconds run time.

As well as the chance to use noise-free gel electrodes if desired, the other reason I like the Wellue is the possibility to catch far more arrhythmia events thanks to the free AI analysis and the 24-hour maximum run time. The AI system can work out all sorts of information, especially when run for longer, such as ectopic load and so on.

Wellue are the consumer arm of a company called Viatom who have been producing professional ECG machines for many years and they do also sell a home 6/12 lead ECG machine, but it's about £400. The AI system has claimed "medical grade accuracy" but it does not have FDA approval for the USA. In terms of home use, and providing a cardiologist with a high quality trace, I suspect it can be bettered.

Steve

[TracyAdmin Partner]

Hello, do you know what model or who old your Samsung watch is? Having just researched FDA guidelines, it would appear that Samsung Galaxy Watch was given clearance by FDA in 2023: mobihealthnews.com/news/sam...

The Alive Kardia Mobile also complies with FDA guidelines: alivecor.zendesk.com/hc/en-...

Therefore, both are deemed as a suitable device in detecting your heart rhythm, however, if you are in doubt, please check with your Dr at your next earliest convenience.

Kind regards

TracyAdmin

[baba in reply to TracyAdmin]

Does FDA have any relevance in UK?

[Stentrunner in reply to baba]

OP is in the US.

[baba in reply to Stentrunner]

But Tracy is in UK.

[Blearyeyed in reply to TracyAdmin]

The Kardia is the one recommended in the UK for NHS patient led monitoring use.

[easygoer13]

Hey thanks to those who replied I really appreciate it I put a lengthier reply up above hope you all are well

[Chinkoflight]

Kardia, especially 6 lead is very reliable and produces an accurate trace according to my GP. Watches unreliable. My smartwatch overestimates high HR by at least 10% so on vigorous exercise can read 180. I have a LINQ implanted loop recorder running 24/7/365 which is set by the monitoring team to trigger high HR event at 158, hasn't been triggered yet in almost 12 months. I have checked with them a specific watch event, to the second of the event and everything was normal on the LINQ.

[1969hippy in reply to Chinkoflight]

It's all Greek to me!

[Chinkoflight in reply to 1969hippy]

I see you are new to the forum. Welcome. I hope the reply was helpful to the person who posted the query. I assure you I don't know Greek but if something is unclear please ask a specific question. On the other hand there is enough to do some basic research on your own. Perhaps look for a #chinkoflight.

[Tellingfibs]

I have the original Kardia. Generalising, if I use my fingers as is described in the main instructions, I get quite a few Afib readings that contradict the results when using my knee - described as an alternative way to use the device. I don’t think people bother with this way as it is much less convenient. However, when I use the knee position, I tend to get ‘ Sinus Rythmn with Supraventricular Ectopics ‘ results. My GP said that in his opinion, it makes sense that the knee position is more accurate. So even one one device contradicts itself - comparing with another must throw up even more doubts !

Annie.

[1969hippy in reply to Tellingfibs]

I don't have any of these devices.

[Blearyeyed]

Basically , if you have both a watch and the Kardia , medical testing has shown that the Kardia reading is the one should rely upon.They also suggest no brand of watch can be used as more than a guideline to then test with a Kardia or preferably get tested with a Medical Grade ECG , especially if you have symptoms.

All watches and the Kardia units were tested against simultaneous Medical ECGs , and the readings were checked on two levels : the automatic assessment that is done by the watch and is seen as an answer instantly on your watch , and a professional assessment of the recorded readings by Medical Professionals from Medical Students to Senior Consultants and EPs.

The research was done by Swiss Medical.

No watches automatic ( algorithm generated diagnosis) accuracy was higher than 63% that was the Apple . The Kardia units came in between 70-80% not that much lower than the Medical Grade ECG after professional assessment of recordings. Most watches automatic readings accuracy for predicting aFib was only accurate between 45-55%.

When double checked by Medical Professionals of all levels aFib recordings were classed as ' inconclusive' in between 22-33% of the time when assessing Smart watch recordings because of poor recordings.

This is because the recorded ECGs have many problems in generating accurate results. These include improper placement of sensers , poor contact of leads to skin because of sweat or skin debris, looseness of device at the time of recording, interference that happens from patient movement ( including tremoring) , the circulation in the arm it is worn on, battery life at the time if testing, and electrical interference from other devices or equipment nearby.

The Samsung Galaxy units came in second lowest in thorough tests on Smart Watch SL-ECGs for predicting aFib in the Swiss Medic research tests.

Smart watches have the same issue relating to the test and automatically algorithm created results when generating diagnosis for any Heart Rhythm and Blood Pressure results too, which is why BP should also be assessed with a cuff monitor.

It's why the Smart Watches can be great indicators of Heart Rate and helping you to moderate your pace of activity or motivate you to be more active in the generally healthy population but any results for more complex issues in patients with diagnosed conditions or recurring symptoms should be double checked by a Medical Professional or rechecked if testing at home with a medically recognised unit like a Kardia or blood pressure cuff for BP before you can be sure that you are having an aFib event , or other cardiac and BP problems.

[ozziebob in reply to Blearyeyed]

Hi,

After an unsuccessful attempt to find it, I am hoping you can help me locate the research by Swiss Medical that you quote in your Reply.

Could you please send me the relevant link via PM?

bob

[FSsimmer]

The bottom line is you cannot totally rely on these devices. I thought of purchasing one, but as I am in Afib 24/7 what it it going to tell me. Cardiologist agreed. They can be a major source of stress and anxiety, something you need to avoid with Afib. A proper 24 Hr or hospital based E£CG interpreted by a trained professional is the norm

[Countrydweller2]

I love my Galaxy smart watch 4 and find it spot on for a suspected Afib stirring. I just wish I could use the blood pressure feature, it's tempting but must do harm with AFib..

[ozziebob]

Just to help your understanding of the 6 different views of your heart measured simultaneously by the Kardia 6L device in a 30 second recording, I will include this well known image. Other devices only measure 1 lead.

6 lead views of Kardia 6L

[WildIris]

I used the original Kardia. I would sit still for a few minutes, then if I was in AFIB, my pulse was always above 80 and the PWave was missing, also the heart rate would be more variable. If my rate was 70 or under, if under 60 definitely, and pretty regular, I was in NSR. When I first started getting AFib, my rate was generally higher than 100, but with regular exercise and a healthier diet, AFib got closer to NSR (then fizzled out).