AliveCor Mobile ECG Update: Successes and Failures

The  AliveCor/Kardia mobile ECG device is a really nifty way to monitor your heart rhythm. Since acquiring the third generation device (which sits within or on my iPhone case and communicates with a smartphone app) I have begun routinely using it  on my patients who need a heart rhythm  check during office visits. It saves us the time, inconvenience (shirt and bra removal) and expense of a full 12-lead ECG which I would normally use.
In addition, I’ve convinced  several dozen of my patients to  purchase one of these devices and they are using it regularly  to monitor their heart rhythms. Typically, I recommend it to a patient who has had atrial fibrillation (Afib)  in the past or who has intermittent spells of palpitations.
Some make daily recordings to verify that they are still in normal rhythm and others only make recordings when symptoms develop.
Once my email invitation request is accepted I can view the ECGs recorded by my patients who have AliveCor devices as I described here.
This monitoring has in many cases taken the place of expensive, obtrusive and clumsy long term event monitors.
In general, it has been very helpful but the device/app makes occasional mistakes which are significant and sometimes for certain patients it does a poor job of making a good recording.

Alivecor Success Stories

One of my patients,  a spry ninety-something year young lady makes an AliveCor recording every day, since an episode of Afib 9 months ago.
And when I say every day I mean it literally everyday. It could be because she is compulsive or perhaps she has programmed the AliveCor to remind her. When I log in to the AliveCor site and click on her name I can see  these daily recordings:Screen Shot 2016-06-17 at 12.40.07 PM
After a month of normal daily recordings, she suddenly began feeling very light headed and weak with a sensation that her heart was racing.
Screen Shot 2016-06-17 at 12.41.13 PMShe grabbed her trusty iPhone and used the AliveCor device attached to it to make a recording of her cardiac rhythm. This time, unlike the dozens of other previous recordings, the device indicated her heart rate was 157  beats per minutes , about twice as fast as usual.
After 5 hours her symptoms abated and by the time of Screen Shot 2016-06-17 at 12.46.52 PMher next recording she had gone back to the normal rhythm.
She made two other recordings during the time she felt bad and they both confirmed Afib at rates of 140 to 150 beats per minute.
In this case, the device definitely alerted her to a marked and dramatic increase in heart rate but was not capable of identifying this as Afib In my experience with several hundred recordings, the device accurately identifies atrial fibrillation about 80% of the time. On rare occasions (see here) it has misidentified normal rhythm with extra beats as atrial fibrillation

Review Options

AliveCor/kardia users  have the option of having their recordings IMG_6936-1interpreted for a fee by a cardiologist or a technician.
My patients can alert me of a recording and I can go online and read the ECG myself and then contact the patient to inform them of my interpration of their heart rhythm and my recommendations.
Another patient made the recording below:Screen Shot 2016-06-18 at 11.32.26 AMAlthough she is  at high risk of having a stroke during the times she is in Afib, we had been holding the blood thinner I had started her on because of bleeding from her mouth. I had instructed her to take daily recordings of her rhythm with the AliveCor until she was seen by her dentist to evaluate the bleeding.
In this case, the AliveCor performed appropriately, identifying correctly the presence of Afib which was the cause of her nocturnal symptoms.

AliveCor Failures

A young woman emailed me that her AliveCor device on several occasions has identified her cardiac rhythm during times of a feeling of heart racing and palpitations as “possible atrial fibrillation.”  When she sent the recordings in to AliveCor to have a paid interpretation, however, the recordings were interpreted as sinus tachycardia with extra beats.  Indeed , upon my review her rhythm was not Afib. Clearly, when the device misidentifies Afib, this has the potential for creating unnecessary anxiety.
It is not uncommon for a full, 12-lead ECG done in the hospital or doctor’s office  by complex computer algorithms to misinterpret normal rhythm as Afib so I’m not surprised that this happens with AliveCor using a single lead recorded from the fingers.
The young woman was advised by AliveCor to try a few things such as using the device in airplane mode, sitting still and wetting her fingers which did not help. She was sent a new device and the problem persisted. She finds that putting the device on her chest gives a better chance of success.
She also runs into a problem I see frequently which is a totally normal recording labeled by the device as  “unclassified.”
In this example, although I can clearly see the p-waves indicating normal sinus rhythm, the voltage is too low for the device to recognize.

Send Me Your AliveCor Problems and Solutions

I’m interested in collecting more AliveCor/Kardia success and failure stories so please post yours in the comments or email me directly at DRP@theskeptical
In addition, I’m interested in any tips AliveCor users have to enhance the success of their recordings: What techniques do you use to make the signal strength and recording better? What situations have you found that tend to worsen the signal strength and recording quality?
Still Unclassified Yours,


P.S. Tomorrow is Cyber Monday and I note that Kardia is running a “Black Friday” special through 11/28, offering the device at 25% off.

P.P.S. Kardia, You should change the statement on your website, “90% of strokes are preventable if you catch the symptoms early.”  makes no sense. I think you mean that some strokes are preventable (I have no idea where the 90% figure come from) if one can detect Afib by utilizing a monitoring device to assess symptoms such as palpitations or irregular heart beat.


12 thoughts on “AliveCor Mobile ECG Update: Successes and Failures”

  1. Thank you
    I use the Kardia device and frequently get “unreadable” or “unclassified” I am primarily using the device to track arrhythmias related to allergic reactions. I have Indolent Systemic Mastocytosis which seems to cause cardiac events as one of the first symptoms. Had cardiac arrest following bone marrow biopsy. This required CPR to recover. I now experience bradycardia followed by afib with rates over 200. Mayo Clinic put in a Pacemaker to help manage. The episodes pass within about an hour….usually. Monitoring for vfib

  2. I am a 43 year old survivor of a massive heart attack in the LAD which resulted in a low ef.
    I use the Alivecor as part of my trouble shooting when I’m not feeling well and/or have chest pain. Of note, I also have an ICD so if something happens I have a back up. I do not have afib but suffer occasional bouts of PVCs. The last time I sent the readings to my cardiologist and she adjusted my meds right away. I also use it during exercise, similar to the monitoring in cardiac rehab.
    I had to learn what to look for since Alivecor only detects certain issues. I wish I knew a little more about what to look for in my readings.

    • Thanks for the input! AliveCor does not recognize PVCS or arrhythmias other than afib. I use it in my office when I detect by exam that the patient is having extra beats to confirm that they are PVCS. I think it could be of great value for patients with palpitations due to PVCs if it could accurately identify them.

  3. Possibly stating the obvious here, but I have learned that usually when I get an “unclassified” result on my Alivecor/Kardia device, it’s because I’m too close to an electronic device. When I move far away as possible from televisions, computers, etc., then I get a valid reading.

  4. Anthony, I am in France at the moment and Kardia shows up Google Play both on my computer and my phone. I have made recordings in France with the device (last year). It’s possible the problem may be specific to certain countries, but at least in France it works.

  5. Hi,
    My successes and failures:
    -about a year ago I let my friend use it. It reported AFib. I paid for an evaluation 2 or 3 times because it kept changing. Alivecor finally had one of their staff evaluate it and refunded all of my payments: it was normal.
    – I believe they use geofencing: when I go to Europe, it stops working (no error, just won’t respond to touch). When I touch down at JFK, it starts working fine. But last week I traveled from home (Costa Rica, where it works fine) to Philadelphia. And it wouldn’t work.
    – if you’re outside the US and go to the Google Play Store, you can’t find Alivecor or kardia. Sometimes if you spoof your IP address it will show up. But mostly, you need to go to the US to download the app.
    I have familial HCM.
    I enjoy your skepticism and your informative ruminations.
    Charlie McDermott

    • Charles, thanks for you comments. My thoughts on them:
      1. ” I paid for an evaluation 2 or 3 times because it kept changing.”
      -by changing you mean the paid evaluations came up with different diagnoses? I’d like to see that problematic tracing.
      -It definitely seems like if AliveCor says Afib and a review declares no Afib that you should be reimbursed.
      Otherwise, Alivecor could generate profts by lowering the specificity of the algorithm
      2. “geofencing”. Not sure how that works and I don’t think I’ve tried to use it out of the country. Would be interested if any international readers have issues.
      Familial hypertrophic cardiomyopathy seems like a good use for the device to look for markers of increased sudden cardiac death risk. I believe I have a form of familial HCM which I’ll write about some day.


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