The KardiaMobile Card Review: Accurate ECG Recording and Analysis From a Credit-Card Sized Device

The skeptical cardiologist has gotten his hands on AliveCor’s brand new KardiaMobile Card and can confirm that it is an amazing development in the personal mobile ECG space.

As announced last week, the Kard is exactly the height and width of a credit card and performs high-quality single-lead ECGs in a manner similar to AliveCor’s larger KardiaMobile.

The Kard

AliveCor should consider using my catchy term for its new phenom-The Kard!

It is 85.6 mm x 54.0 mm x 1.2 mm, has two 25 by 15 mm electrodes, and weighs 7.4 grams. It runs off a non-replaceable lithium manganese oxide battery designed to last 2 years and utilizes Low Energy Bluetooth technology to communicate with most smartphones.

The Kard weighs less than the Venture X VISA card I just received and it now resides permanently in my wallet ready to spring into action should I or someone near me require a single-lead ECG.

The front of the Kard consists of a left and right electrode an LED light and a power button

the recently polished index fingers of the former Eternal Fiancee’ in proper position on the Kard’s electrodes.

Setting Up and Using The Kard

If this is your first time using a Kardia device you will need to download and launch the Kardia app from the App Store (Apple iOS) or Google Play (Android smartphones) and create a Kardia account. The list of compatible devices can be viewed at

The Kardia app is a great way to aggregate your ECG, blood pressure and weight measurements.

Once the app is set up, select the Profile tab on the bottom navigation bar and the screen to the left should appear. Under devices you can see that I have previously connected my KardiaMobile 6L and 2 BP monitors to the app.

Select manage devices.

the Kard should appear as a choice at this point. Pairing between the smarphone kardia app and the Kard was quick and easy.

Making an ECG Recording

Making a recording with the Kard is simple and very similar to making one with KardiaMobile with the exception that you have to squeeze the little power button (pick it up using your index finger and thumb, and squeeze the power button with your thumb) until you feel a click at which point the LED light comes on and the device is activated. Unlike the original KardiaMobile devices, the Kard turns itself off after 10 seconds to conserve battery life.

The Kard communicates via Bluetooth with the smartphone app so make sure that Bluetooth is turned on on your phone.

Battery conservation is important because once the battery dies, the Kard is useless, whereas with KardiaMobile it could be replaced.

To make an ECG recording you can employ one of two approaches: 1) Grasp the card in both hands with one thumb on each electrode or 2) Place it flat on a solid surface and put an index finger from each hand on the electrodes. Stay very still for 30 seconds while the ECG is being recorded.

The first recording I made with the Kard came back unclassified because I never got a good stable connection.

Poor quality ECG. Note marked variation in the baseline (red line) which improves near the end of the recording but not enough for the algorithm to feel confident in identifying the rhythm

This was easily corrected by making sure my thumbs were parallel to the long axis of the rectangular electrodes which maximizes the area of contact between thumb skin and metal.

Second recording with better thumb positioning. Note that the ECG baseline (outlined by red line) becomes very stable within a few beats of starting the recording.

Other tips for avoiding poor recordings and unclassified readings include moistening your fingers if they are dry, concentrating on staying very still (which is easier if the KMC is flat on the table), and avoiding squeezing too hard.

Instant analysis

Like KardiaMobile single and 6 lead devices, the single, Lead I recording is analyzed by Kardia’s instant analysis AI algorithm on the smartphone which can recognize, very reliably, abnormal and normal heart rhythms.

All historical EKGs and Instant Analysis results can be viewed, downloaded, and emailed from the “History” section of the Kardia app

Cost, KardiaCare and Other Factors

AliveCor sells the Kard for $149 on their website and that buys you a one-year “KardiaCare Membership.” The Kard is only available with an annual KardiaCare membership (unlike the other KardiaMobile devices.) Per AliveCor you will be automatically renewed after the first year and charged $99/year. Your device will work for the lifetime of your membership

And per Dr. Dave Albert of AliveCor (email communication) “if you have a currently active subscription and your battery dies, you will be sent a replacement card at no additional cost.”

I’ve been meaning to write in detail about KardiaCare and will soon. Importantly the Advanced Determinations of the AliveCor Analysis algorithm are only available with KardiaCare membership.

Comments From A User/Reader

A reader of my blog posted this comment the other day :

I received my new KardiaMobile Card in today’s mail. I like it a lot. I compared the readings alongside my original KardiaMobile using advanced determinations and my KardiaMobile 6L. The readings itof all three devices correlate exactly.

It’s great to be able to put the KardiaMobile Card in my wallet which is why I bought it. I keep it between a couple of credit cards so it stays protected from bending. The power shuts off automatically after 10 seconds of no use so I don’t have to worry about remembering to turn it off and inadvertently running down the internal battery.

Readers may wonder if they are losing anything by having only a single lead ECG with the Kard versus the six leads a Kardia 6L offers. I tend to think the vast majority of users are not losing out and agree with this reader’s comments on the matter:

I’ve used the 6L 6-lead device regularly since they first became available and it does give more information, but in my case I never found having more information to be of real value over the single lead device. I also found the 6L to be bothersome in the aspect that I either had to pull up one pvaiant leg or pull down a sock to be able to take a 6-lead reading.

Overall, I view the Kard as another wonderful contribution to personal ECG and remote monitoring. Most people carry a wallet or a combined cell phone/credit card accessory with them almost all the time. If the Kard is sitting in that accessory it will be available if and when rhythm analysis is warranted.

This development puts AliveCor on equal footing with Apple Watch ECG for ease and simplicity of real world use but at a lower price point and with the advantage of AliveCor’s Advanced Determinations.

Walletingly Yours,



17 thoughts on “The KardiaMobile Card Review: Accurate ECG Recording and Analysis From a Credit-Card Sized Device”

  1. I have SVT. My cardiologist, which was new due to insurance, didn’t believe me. He thought I diagnosed myself using the internet. I was diagnosed 35 years ago and have been converted with meds many times and once I was hospitalized for it. My cardiologist told me to get this and capture an episode. So I did and he was shocked that I wasn’t making this up. He said “you really do have SVT, hmmmm” The fact that I had to go through all of this when he could have just gotten my medical records is enough to make me look for another doctor. If he is so non trusting, that indicates he can’t be trusted.

  2. Hi Dr. P.,
    I just received a one lead pacemaker in the context of bradycardia, a heart block and possible persistent AFIB. Query, will the pacemaker override the richness of the information I can get from the Kardia unit? Thanks much !!.

    • Allan,
      Generally, one gets a “one-lead” pacemaker with just the ventricle being stimulated when one has permanent atrial fibrillation.
      If you have heart block and permanent atrial fibrillation, I venture to say that you will get very little useful information from the Kardia.
      Rhythm in that situation is typically 100% paced and that will really confuse the AI algorithm.
      Dr P

  3. Kardia has been a life saver through diagnoses of PAF/AF/Atrial Flutter as i travel frequently it provides peace of mind to worried patients and helps doctors document and correct issues as they occur. My doctor at Cedars-Sinai alerted me to this product and i’m very grateful! Thanks Kardia!!

  4. Read your latest about the new Kardia card. Apparently they have a pretty good revenue stream from Kardia care and this will drive up the numbers participating. I had that service for a year but frankly didn’t find it that useful. The couple times I submitted a review request, it came back with simply ” normal”. I guess for someone without a regular cardiologist it could be helpful but I see my doctor twice a year. My main use is to check my rhythm daily to be sure I’m not going into AFib, which I cannot feel. So far about 2 years and all normal.
    Good news, after seeing actors in the new commercials saying the doctor will thank you now, the old testimonial is playing again. So that’s good for my ego!
    Warren from Syracuse

  5. As I commented before, it would be much better to simply put one finger on a watch to see EKG strip immediately on the watch face. No card/no phone


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