Comparing ECG Wearables: SonoHealth, Apple, AliveCor

— The Skeptical Cardiologist finds... much to be skeptical about

Last Updated September 13, 2019
MedicalToday

The Skeptical Cardiologist keeps his eyes open for new, potentially improved ways of personal mobile ECG monitoring, so when I saw the following comments on an atrial fibrillation forum I was intrigued:

"I recently started using a SonoHealth product that I find MUCH MUCH superior to Kardia..."

Really? MUCH MUCH superior? The more someone utilizes all caps to emphasize a point, the less I tend to believe it. But, as I am on a mission to discover the truth in all things cardiologic, I went to the SonoHealth website and encountered this:

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The EKGraph would indeed appear to be MUCH MUCH superior to Kardia mobile ECG, if the website marketing can be believed.

Like the Kardia, the EKGraph offers a personal ECG monitor obtained using the fingertips that syncs to an app on your smartphone.

The EKGraph claims to have three lead capability, something it emphasizes in its marketing, but it is only capable of displaying one lead at a time and, similar to Kardia, one can obtain lead II and precordial ECG leads by putting one electrode on the leg or chest.

Also similar to Kardia, the EKGraph promises "rhythm detection." As we shall learn, however, rhythm detection by the EKGraph cannot be trusted, whereas Kardia has a wealth of published data supporting its accuracy.

Unlike the Kardia, the EKGraph does have a "bright LCD screen" that displays the ECG wave pattern and heart rate along with the heart rhythm diagnosis.

I emailed SonoHealth and they were kind enough to send me one of their ECG devices to demo. A few days later, a package arrived containing the EKGraph in an Apple-esque box that also contained a USB charging cable. In addition, they included a carrying case and a tube of ECG gel.

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After spending some time with it, I can say unequivocally that it should not be purchased or utilized by any patient who wants reliable personal mobile ECG monitoring with accurate diagnoses.

Working with the SonoHealth App

To make a recording, one puts the metal strip on the left side of the device on a hand, arm, or leg and the other metal strip on the right side of the device on an opposing limb or the chest.

This very happy model gives you a feel for the size of the device and the method of making a Lead I recording.

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It is possible to make a decent single lead ECG tracing with this device and view the tracing on the associated smartphone application. However, the recordings are typically very noisy and full of artifact, making it hard to discern the rhythm. The software appears to lack appropriate filtering.

The SonoHealth app is free but getting it registered was a problem. On the company website support area, several readers have complained of the same problem over the last few months:

I am having trouble registering on the phone because when I hit the red button to register, I see the email and username fields at the top of the form, but when I click on email, the info fields jump to name, and I can't scroll up to access those two fields. I then get a notification that those two fields are required to register. Any suggestions?

There is no response to this issue posted 3 months ago from the company.

Syncing with the app via Bluetooth is straightforward. Pressing the sync button transfers all new tracings to the app where they can be reviewed.

Tracings can be emailed or printed.

Rhythm Detection

The major problem with the EKGraph is that its ability to diagnose rhythm is very limited. This device has no published data verifying the accuracy of its rhythm diagnoses, whereas the Apple Watch 4 and Kardia ECG devices do. It is not approved by the FDA.

I used the device on myself twice and, despite identical rhythms, the EKGraph called one "tachycardia" and the other "bradycardia."

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I tried using the SonoHealth on patients in my office who were in normal sinus rhythm and received wild, seemingly random diagnoses.

Whatever algorithm the device is using to diagnose rhythm is clearly not making allowances for poor quality recordings.

This patient is in normal sinus rhythm, but the EKGraph calls it "tachycardia, VPB bigeminy" mistaking the artifact between the normal QRS beats and ventricular ectopic beats.

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Multiple Sketchy Companies with Similar Hardware

I have noted other mobile ECG devices with a remarkably similar appearance to the EKGraph. A search on Amazon yields AliveCor's devices and the SonoHealth EKGraph. The Amazon comparison page shows three additional devices appearing identical to the EKGraph but seemingly from three different sketchy companies, all priced at $79.

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A consumer asked SonoHealth about the identical external appearance of SonoHealth's and EMAY's devices and the company's response was:

"As a small new company making a new design for the outside shell didn't seem viable. A mold from scratch costs anywhere from $65,000-$85,000. So our manufacturer allowed us to use their current mold to make the EKGraph."

"So even though the outside is similar the software side is totally different. We have new and improved software. There's also our own SonoHealth app that we developed from scratch."

"SonoHealth is a USA company that provides excellent customer support."

I would disagree with SonoHealth's assessment -- there is nothing to suggest their software is either new or improved or even accurate.

The app that they developed from scratch is clunky and difficult to use.

Ratings and Online Presence of SonoHealth

SonoHealth posts on its website alleged reviews of the EKGraph. They are uniformly positive. It's hard to find anything that isn't 5/5 stars. Apparently, all the problems I found with the product are unique to me.

However, these reviews should be taken with a grain of salt. A few weeks after acquiring my SonoHealth EKGraph, I received an email from the company offering a gift card if I followed their precise instructions in writing a review:

TERMS: In order to receive the $10 giftcard reward you MUST write both a Company and a Product review. We will send each reviewer the egiftcard to the email that they provided when leaving the review. (For verification purposes, the email you enter when leaving the review must match the email associated with your order.)

This manipulation of the review process is shady and calls into question the validity of any review on the company website or on Amazon.

Let the (Mobile ECG) Buyer Beware

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 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 naïve 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 with a physician and is well worth the dollars spent.

Please also note that I have no financial or consulting ties to AliveCor. I'm just a big fan of their products.

, is a private practice noninvasive cardiologist and medical director of echocardiography at St. Luke's Hospital in St. Louis. He blogs on nutrition, cardiac testing, quackery, and other things worthy of skepticism at , where a version of this post first appeared.