An In-depth, Objective Comparison of Mobile ECG Devices: Emay versus Kardia

The skeptical cardiologist has been a huge advocate of personal mobile ECG monitoring to empower patient’s in understanding/monitoring their heart rhythm.

The deserved leaders in this field are the Apple Watch (4 and later) and Alivecor’s Kardia device which comes in single-lead and six-lead flavors.

Both Apple and AliveCor have gotten FDA approval for their mobile ECG device and have a body of published studies supporting their accuracy.

In contrast, there are a number of “copy-cat” mobile ECG devices which have been feeding on the success of Apple Watch and Kardia but do not have the bona fides the two leaders have.

I reviewed the SonoHealth ECG here and found it sorely lacking in comparison to Kardia in terms of accuracy of diagnosis and quality of recordings, the two most important aspects of a personal ECG monitor.

Dan Field, a physician  and reader of my blog, has been evaluating a device similar to the SonoHealth ECG made by Emay.

He has provided a point by point comparison of the two  devices in the chart below

Emay versus Kardia

His summary:

“The Kardia6L was clearly superior in almost every way except for price and even that was within the margin of error. ”

It should be noted that the single lead Kardia mobile ECG is actually cheaper than the Emay and retails for $99.

Let The (Mobile ECG) Buyer Beware

I ended my post reviewing SonoHealth’s ECG with a warning which applies equally to the Emay device:

The SonoHealth EKGraph is capable of making a reasonable quality single lead ECG. Presumably all the other devices utilizing the same hardware will work as well.

However, the utility of these devices for consumers and patients lies in the ability of the software algorithms to provide accurate diagnoses of the cardiac rhythm.

Apple Watch 4 and AliveCor’s Kardia mobile ECG do a very good job of sorting out atrial fibrillation from normal rhythm but the SonoHealth EKGraph does a horrible job and should not be relied on for this purpose.

The companies making and selling the EKGraph and similar devices have not done the due diligence Apple and AliveCor have done in making sure their mobile ECG devices are accurate.  As far as I can tell this is just an attempt to fool naive patients and consumers by a combination of marketing misinformation and manipulation.

I cannot recommend SonoHealth’s EKGraph or any of the other copycat mobile ECG devices. For a few dollars more consumers can have a proven, reliable mobile ECG device with a solid algorithm for rhythm diagnosis. The monthly subscription fee that AliveCor offers as an option allows permanent storage in the cloud along with the capability to connect via KardiaPro with a physician and is well worth the dollars spent.

Skeptically Yours,




18 thoughts on “An In-depth, Objective Comparison of Mobile ECG Devices: Emay versus Kardia”

  1. Hi. I’m very interested to use the Kardiamobil but I have a question. To use it, it only has to be in sitting position, that is sitting on a chair and the device on a table? Because most of the time that I don’t feel well, it happens when I’m walking (in the park for example). Thank you for this article, it helps me.

    • Yes. You have to be quite still to get a useable ECG recording using most all ECG recording mechanisms.
      Your best bet trying to capture exercise ECG abnormalities with Kardia devices is to stop immediately and make a recording. These don’t have to be sitting but the arms/fingers must be very still.

  2. I bought another Contec PM10 clone (the Emay is also a clone) a few days ago at for a bit more than 50 Euro to play with. I had my 2nd cardioversion 2 days ago and the good thing was that my Garmin Vivoactive 4 showed that my elevated HRV started at night at around 2AM. I already used an Android app that makes a Poincarre scatterplot from the R-R interval in 30 seconds, and that also helped to indicate that something had changed (and of course I felt it myself). So I was able to show that it started within 24 hours.
    It is good to read this article and be aware that the Contec PM10 clones are devices that shouldn’t be trusted. Personally, as an engineer, I like to use multiple sources of data and see what correlates and works. I certainly wouldn’t advise a neighbor to buy it now, so thanks!

  3. Dr. Pearson,

    Thank you very much for the nice article. I do regularly use Kardiamobile 6L device.
    However i always experienced that the kardiamobile device is not good at sensing the finger touch on leads. it always take 5/6 attempts to record one EKG.
    I do see lot of such reviews online about Kardiamobile device.
    What is your and your patient experience? It will be good if you can include that point in your article as it will help the future buyers.

    I also came across the device from Wellue ( which claims to test all vitals and it is FDA and CE approved.

    Oxygen Level
    Body Temperature

    It will be great if you can provide your opinion on this device.

    They also have variety of products.

  4. I have ten stents since 2005, and CVD probably for the last 40 years.

    I cannot agree with your summary of the three appliances (Apple, Kardia, and SonoHealth)–I’ve used all three. All three have issues, some more costly than others (albeit I used older versions). Bottom line is to use a cardiologist or primary care instrument with more leads, for a more detailed analysis.

    The hand held monitors only establish comfort levels to the user, to better understand and ultimately communicate with their doctor.

    However, Apple and Kardia have more problems that Sono, especially costs and customer care. Each of them have subscriptions in order to effectively use them and preserve data. And mountains of ads. Signal interference. Costly initial setup issues (cardio has to approve first use $$$ for continued usage for Kardia). Heavy marketing to 3rd parties, Apple tries to override Kardia with its own version for its own phones

    Sono also has its issues, especially in saving records (i.e save times, and dates, data transfer to desktop, and printing). Sono is limited to the first 100 readings, and then overwrites past data. Sono only has two leads, where one lead can be two fingers or extend to leg or arm.

    My experience was far better with Sono–an example: In Dec 2018, rec’d a great EKG from cardio in office; two weeks later I suffered increased heart rate. Did my Sono reading which showed 120 bpms+ and tachycardia. Went back to cardio a month later, verified AFIB in his office.

    Three months later did conversion, a month afterward Sono showed brady leading back to tachy (35 bpms to 100 in one month). Verified AFIB again, went to ablation therapy, now maintain at 50-60 bpms.

    The important takeaway is that a user should not implicitly nor solely trust these instruments, which are merely interim on the way to your doctor. The Sono results mirrored a Holter monitor and cardio’s EKG as well, when needed, although in simpler form (i.e., leads)

    It also mirrored FitBit, which batteries never lasted beyond two days. Sono lasted over two weeks under constant use–and can be recharged with USB vs, buying a new battery with Kardia. Again, I only used older versions of the three. Sono also consistently updates their app and had immediate customer service (for ex., immediately replaced a bad unit when confronted with their error).

    I like your website…

  5. ACP: i know this may seem no way to give u a sincere compliment: u & I fight like cats and dog over diet. Your work here re a fib/e devices is absolutely 1st rate. U could help an experienced brother out: re your take on anticoag of elderly (65+) a fib wi Cha2DS2-Vasc score of 0, 1, 2. Add in low vs moderate a fib burden. I keep getting from published and local experienced, even EPS, people that it is not clear. Mebbe that is the answer. Thx & congrats again. HRS, MD, FACC

    • HRS,
      Thanks for the compliment! we can always agree to disagree over diet. Maybe 10 years from know science will prove you correct and I will be in your camp.
      Is the CHADS2 score in addition to the point the 65+ gets for being 65-75?

  6. Thanks as always for continuing to watch for new ways for patients to better understand their heart rhythms, and to better communicate their concerns and progress with their doctor. I love my Kardia (1lead) and love when there are long gaps between the times I need to use it. I saw my EP for my annual visit this past week and after I told him about my 3 episodes this past summer, I brought up the Kardia history just to remind him I had it. He absolutely wanted to review the readings and made notes in my file. He is still a fan. We’re both feeling optimistic that with my recent (and continued) weight loss and recent addition of CPAP, I may be able to reduce my flecinaide dose, or even stop it. Thanks again.

    • Julie,
      Thanks for your kind words. I am so happy you’ve found an EP who is working with you and your Kardia recordings and is pursuing what seems like an enlightened medical management of your afib!
      Too often EPs are like the man with a hammer….
      Dr P

      • Sadly, Kardia is limited to only a few smartphones, and does not offer support to others. I’ve been a Marcia user for many years, but recently mine abruptly stopped working and I was told it was because my phone was not on their list…despite the fact that I had been using the phone with it successfully for a year.

  7. My only issue with the Kardia is it confuses my pvcs as a fib . My pvc burden is 6% . So my cardiologist has to read them in order to reassure me that im not in afib

    • Barb,
      I’m glad you brought this up.
      There is no $120 dollar fee to use the Kardia device alone.
      One can make all the ECG recordings one wants and email them to yourself or a doctor without charge with the Kardia device.
      The idea that one needs to pay a subscription fee for Kardia seems to be a talking point/marketing point for the copycat manufacturers.

      What you paid $120 for was a combination of the Kardia recording device plus a one year subscription to the online cloud service which stores all the tracings and makes them accessible to your cardiologist online in a convenient summary/report/dashboard format. Subsequent one year subscriptions to this online service is $60.

      This premium service is an amazingly helpful tool in managing my patients with atrial fibrillation.

      • are you piad by Kardia? I was going to get the Wellue portable device which costs a bit more and had two extra wires for leads you can use. But the whole reason I got the emay was for the diagnosis of why it thinks something was abnormal. The wellue just tells your normal or abnormal. If i have to subscribe for that from Kardia I’m not going to buy it. Seems Shady. I’m also not going to buy a device to do an ekg just to have a doctor analyze it. Might as well just have the doctor do the ekg as well. I know I’m probably being foolish and no matter what the emay says I would need a doctor to analyze it. And most likely the wellue is a better machine. But its human nature to want to know and emay has got me there.

        • Richard,
          I don’t receive a dime from Kardia. In previous posts I’ve pointed out deficiencies of their algorithms.
          There is nothing shady about Kardia or AliveCor. AlivecCor has proceeded very carefully in developing their products. They have strong scientific backing for their results. They have FDA approval for anything they market.
          The subscription fee with Kardia is optional but allows “advanced determinations”.
          The Emay provides very unreliable diagnoses and has no scientific studies supporting its accuracy.
          As for Wellue . I have been provided with a demo device by the company but haven’t gotten around to testing it.
          Dr P

    • I’m addressing the kardia device, not your particular situation. Please excuse me if this distracts from your issues.

      I have had AF and PVC for decades. Two ablations, lots of meds, still happens. So I thought to get a heart monitor to ‘see’ how serious the current excursions were. Shopped around, found Kardia 6 lead…looked good, bought it.

      It arrived. Nice object. Well designed. No user interface…depends on bluetooth to ‘talk’ to a cellphone or tablet which then displays the data, which is most of why the product price point is relatively low. But the software is, well, demanding. First off, it requires a minimum operating system update. Then the install requires your name, weight, height, address, and access to the phone’s gps data.

      I wrote Kardia and asked why they want that data since all the software did was display data from the device. The wrote me back and said it was all OK since it was in the ‘terms of service’. Insofar as those terms of service are part of the install process, that is quite the catch-22. The only way they could use this data is if the software streamed my cardiac info to them, a clear breach of HIPAA.

      I need the device. Without the display function it is useless. So I must allow this data shakedown. But I will post my objections to every forum that will allow me to do so in hopes the court of public opinion will encourage Kardia to amend their ways.


Please leave your comments. The skeptical cardiologist loves feedback. He reads all and replies to all that warrant a reply.