Tag Archives: Apple Watch 4

A Guide To Using Apple Watch and Kardia ECG devices-What They Can and Can’t Do

Many patients (and perhaps physicians) are confused as to how best to utilize personal ECG devices. I received this question illustrating such confusion from a reader recently:

I first came across your website a year ago during persistent angina attacks, and returning now due to increasing episodes of symptoms akin to Afib. I bought a Kardia 2 yrs ago for the angina episodes, and looking to buy the Apple Series 4 for the Afib, as I want to try a wearable for more constant monitoring. What I would greatly appreciate if you had a basic guide for both the Kardia & Apple devices, specifically when and how to best employ them for unstable angina and detecting undiagnosed Afib. As in, what can I as a patient provide to you as a doctor for diagnosis in advance of a formal visit. I’m a US Iraq vet medically retired in the UK, and most of my concerns get dismissed out of hand as “anxiety”, not sure why they thought a stent would cure my anxiety though  

Personal, Wearable ECG Devices Won’t Diagnose Angina (or Heart Attacks)

First. please understand that none of these devices have any significant role in the management of angina. Angina, which is chest/arm/jaw discomfort due to a poor blood supply to the heart muscle cannot be reliably diagnosed by the single lead ECG recording provided by the Apple Watch, the Kardia Band or the Kardia mobile ECG device. Even a medical-grade 12 lead ECG doesn’t reliably diagnose angina and we rely on a constellation of factors from the patient’s history to advanced testing to determine how best to manage and diagnose angina.

Second, as you are having episodes “akin to Afib”, all of these devices can be helpful in determining what your cardiac rhythm is at the time of the episodes if they last long enough for you to make an ECG recording.

The single lead ECG recording you can make from the Apple Watch, the Kardia Band and from the Kardia mobile device can very reliably tell us what the cardiac rhythm was when you were feeling symptoms.

The algorithms of these devices do a good job of determining if the rhythm Is atrial fibrillation. Also, if the rhythm is totally normal they are good at determining normality.

However, sometimes extra or premature beats confuse the algorithms resulting in an unclassified tracing and (rarely) an inaccurate declaration of afib

These tracings can be reviewed by a competent cardiologist to sort out what the rhythm really is.

In all of these cases, having an actual recording of the cardiac rhythm at the time of symptoms is immensely helpful to your doctor or cardiologist in determining what is causing your problems.

My recommendation, therefore, would be to make several recordings at the time of your symptoms. Print them out and carefully label the print-out with exactly what you were feeling when it was recorded and present these to the doctor who will be reviewing your case.

As I’ve mentioned in previous posts (see here), my patients’ use of Kardia with the KardiaPro online service has in many cases taken the place of expensive and inconvenient long term monitoring devices.

Case Example-Diagnosing Rare And Brief Attacks Of Atrial Fibrillation

I recently saw a patient who I think perfectly demonstrates how useful these devices can be for clarifying what is causing intermittent episodes of palpitations-irregular, pounding, or racing heart beats.

She was lying on a sofa one day when she suddenly noted her heart “pumping fast” and with irregularity. The symptoms last for about an hour. She had noticed this occurred about once a year occurring out of the blue.

Her PCP ordered a long term monitor, a stress test and an echocardiogram.

The monitor showed some brief episodes of what I would term atrial tachycardia but not atrial fibrillation but the patient did not experience one of her once per year hour long episodes of racing heart during the recording. Thus, we had not yet solved the mystery of the prolonged bouts of racing heart.

She was referred to me for evaluation and I recommended she purchase an Alivecor device and sign up for the KardiaPro service which allows me to view all of her recordings online. The combination of the device plus one year of the KardiaPro service costs $120.

She purchased the device and made some occasional recordings when she felt fine and we documented that these were identified as normal by Kardia. For months nothing else happened.

Then one day in April she had her typical prolonged symptom of a racing heart and she made the recording below (She was actually away from home but had the Kardia device with her.)

When she called the office I logged into my KardiaPro account and pulled up her recordings and lo and behold the Kardia device was correct and she was in atrial fibrillation at a rate of 113 BPM.

With the puzzle of her palpitations solved we could now address proper treatment.

Continuous Monitoring for Abnormal Rhythms

Finally, let’s discuss the wearables ability to serve as a monitor and alert a patient when they are in an abnormal rhythm but free of any symptoms.

My reader’s intent was to acquire a device for “constant monitoring”:

I’m looking to buy the Apple Series 4 for the Afib, as I want to try a wearable for more constant monitoring.

This capability is theoretically available with Apple Watch 4’s ECG and with the Kardia Band (using SmartRhythm) which works with Apple Watch Series 1-3.

However, I have not been impressed with Apple Watch’s accuracy in this area (see here and here) and would not at this point rely solely on any device to reliably alert patients to silent or asymptomatic atrial fibrillation.

In theory, all wearables that track heart rate and alert the wearer if the resting heart rates goes above 100 BPM have the capability of detecting atrial fibrillation. If you receive an alert of high HR from a non ECG-capable wearable you can then record an ECG with the Kardia mobile ECG to see if it really is atrial fibrillation.

At 99$, the Kardia is the most cost-effective way of confirming atrial fibrillation for consumers.

I hope this post adds some clarity to the often confusing field of personal and wearable ECG devices.

Electroanatomically Yours,

-ACP

Putting The Apple Watch 4 ECG To The Test In Atrial Fibrillation: An Informal Comparison To Kardia

My first patient this morning, a delightful tech-savvy septagenarian with persistent atrial fibrillation told me she had been monitoring her rhythm for the last few days using her Apple Watch 4’s built in ECG device.

Previously she had been using what I consider the Gold Standard for personal ECG monitoring- AliveCor’s Kardia Mobile ECG   and I monitored her recordings through our Kardia Pro connection.

I had been eagerly awaiting Apple’s roll out since I purchased the AW4 in September (see here) and between patients this morning I down-loaded and installed the required iPhone and Watch upgrades and began making AW4 recordings.

Through the day I tried the AW4 and the Kardia on patients in my office.

Apple Watch 4 ECG Is Easy and Straightforward

The AW4 ECG recording process is very easy and straightforward. Upon opening the watch app you are prompted to open the health app on your iPhone to allow connection to the Watch ECG information. After this, to initiate a recording simply open the Watch ECG app and hold your finger on the crown.

Immediately a red ECG tracing begins along with a 30 second countdown.

Helpful advice to pass the time appears below the timer:

“Try Not to move your arms.”

and

“Apple Watch never checks for heart attacks.”

When finished you will see what I and my patient (who mostly stays in sinus rhythm with the aid of flecainide) saw-a declaration of normality:

Later in the day I had a few patients with permanent  atrial fibrillation put on my watch.

This seventy-something farmer from Bowling Green, Missouri was easily able to make a very good ECG recording with minimal instruction

The AW4 nailed the diagnosis as atrial fibrillation.

We also recorded a Kardia device ECG on him and with a little more instruction the device also diagnosed atrial fibrillation

After you’ve made an AW4 recording you can view the PDF of the ECG in the Health app on your iPhone where all of your ECGs are stored. The PDF can be exported to email (to your doctor) or other apps.

ECG of the Bowling Green farmer. I am not in afib.

Apple Watch Often “Inconclusive”

The AW4 could not diagnose another patient with permanent atrial fibrillation and judged the recording “inconclusive”

The Kardia device and algorithm despite a fairly noisy tracing was able to correctly diagnose atrial fibrillation in this same patient.

I put the AW4 on Sandy, our outstanding echo tech at Winghaven who is known to have a left bundle branch block but remains in normal rhythm and obtained this inconclusive report .

Kardia, on the other hand got the diagnosis correctly:

One Bizarre Tracing by the AW4

In another patient , an 87 year old lady with a totally normal recording by the Kardia device, the AW4 yielded a bizarre tracing which resembled ventricular tachycardia:

Despite adjustments to her finger position and watch position, I could not obtain a reasonble tracing with the AW4.

The Kardia tracing is fine, no artifact whatsoever.

What can we conclude after today’s adventures with the Apple Watch ECG?

This is an amazingly easy, convenient and straightforward method for recording a single channel ECG.

I love the idea that I can record an ECG whereverI am with minimal fuss. Since I wear my AW4 almost all the time I don’t have to think about bringing a device with me (although for a while I had the Kardia attached to iPhone case that ultimately became cumbersome.)

Based on my limited sample size today, however, the AW4 has a high rate of being uncertain about diagnoses. Only 2/3 cases of permanent atrial fibrillation were identified (compared to 3/3 for the Kardia) and only 4/6 cases of sinus rhythm were identified.

If those numbers hold up with larger numbers, the AW4 is inferior to the Kardia ECG device.

I’d rather see the AW4 declare inconclusive than to declare atrial fibrillation when it’s not present but this lack of certainty detracts from its value.

What caused the bizarre artifact and inconclusive AW4 tracing in my patient is unclear. If anybody has an answer, let me know.

We definitely need more data and more studies on the overall sensitivity and specificity of the AW4 and hopefully these will be rapidly forthcoming.

For most of my patients the advantages of the AW4 (assuming they don’t already have one) will be outweighed by its much greater cost and we will continue to primarily utilize the Kardia device which will also allow me to view all of their recordings instantaneously in the cloud.

Conclusively Yours,

-ACP

Note. The original version of this post had the wrong ECG tracing for the first “inconclusive” AW4 recording of a patient with permanent atrial fibrillation. H/t to discerning reader Vignesh for pointing this out months after the initial posting.

My New Apple Watch 4 Is Nice: But It Won’t Record ECGs or Work With KardiaBand!

The skeptical cardiologist picked up an Apple Watch 4  at the Galleria Apple Store in St. Louis today.  The Apple employee who retrieved it told me that ECG recording capabilities were expected in the fall. Of course fall began today and it is not at all clear when, if ever, Apple will provide the software update to its AW4 that will provide ECG capabilities.

Fortunately, consumers already have the capability of  recording a medical grade single lead ECG with any Apple Watch 2 or 3-using the KardiaBand from AliveCor.

Apple has hubristically proclaimed the AW4 as the  ultimate guardian of our health and while setting it up I was asked if I wanted the watch to notify me if my heart rate dropped below 40 bpm for 10 minutes. Sure! Let’s see how irritating this feature will be.

 

 

After setting up the new watch I immediately attached my KardiaBand and installed the Kardia Apple Watch app.

I was able to open the Kardia app and it performed its normal SmartRhythm monitoring but when I tried to record an ECG, alas, nothing happened.

It appears that the KardiaBand does not work with the new Apple Watch 4. Yet.

I was informed by Ira Bahr at AliveCor that their “testing on AW4 is not yet complete. So at present, the device is not supported.”

Now I face a difficult decision-Do I wear my new AW4 with a non KardiaBand wrist band (and no ECG capability) or wear my old Apple Watch with the KardiaBand (and outstanding ECG capability.)

ACP

Apple’s Alternative Facts And The Giant Watch Restaurant Next Door To AliveCor

As I pointed out Friday,  Apple’s claim that the ECG sensor on their new Apple Watch 4  (available “later this year”) is  “the First ECG product offered over the counter directly to consumers” is totally bogus.

AliveCor’s Kardia mobile ECG device was approved by the FDA  for over the counter direct to consumer sales on February 10, 2014. Apple had to have known this as they worked with AliveCor to bring the first Apple Watch based ECG device to FDA approval in 2017.

I tried but failed to get AliveCor founder Dr. David Albert’s thoughts on Apple’s disinformation but Yahoo finance was able to speak to Vic Gundotra, the CEO of AliveCor:

Over at the headquarters of AliveCor, a startup based in Google’s hometown of Mountain View, they, too, were surprised by the announcement, CEO Vic Gundotra said in a phone interview on Thursday. Gundotra is a former Googler, widely known as the executive behind the Google+ social network.

Specifically, Gundotra says that his company was confused by Apple’s claims that the Series 4 will be the first over-the-counter ECG testing device for consumers. AliveCor is a 49-employee startup that makes over-the-counter ECG testing devices and software, including an FDA-cleared band for the Apple Watch, called KardiaBand, and a version that attaches to a smartphone, called Kardia.

Gundotra was also surprised by Apple’s claims of ECG primacy

“We were watching [the announcement], and we were surprised,” Gundotra said. “It was amazing, it was like us being on stage, with the thing we’ve been doing for 7 years,” referring to AliveCor’s product for detecting atrial fibrillation  (AFib), a tough-to-spot heart disorder that manifests as an irregular, often quick heart rate that can cause poor circulation.

“Although when they said they were first to go over-the-counter, we were surprised,” he continued. “Apple doesn’t like to admit they copy anyone, even in the smallest things. Their own version of alternative facts.”

One man’s alternative fact is another (less polite) man’s lie.

Gundotra apparently views Apple’s entry as a good thing

“We love that Apple is validating AFib; just wait until you see what AliveCor is going to do next,” he said. “We were a great restaurant in a remote section of town, and someone just opened a giant restaurant right next to us, bringing a lot more attention.”

And as I pointed out previously, the AliveCor mobile ECG device (not the Kardia Band) is significantly cheaper than an Apple Watch and has multiple studies showing its accuracy. Interestingly, Gundotra indicates AliveCor sales has increased after the Apple announcement,.

“Ours is $99, theirs is $399, our sales popped yesterday, big time,”

Antialternafactively Yours,

-ACP

The New Apple Watch 4: Cardiac Accuracy Unknown, “Game-Changing” Benefits Overblown

On February 10, 2014 AliveCor, Inc. announced that its heavily validated personal  mobile ECG monitor had received FDA over-the counter clearance. Previously the device, which allows recording of a single-lead ECG and, in conjunction with a free smart-phone app, can diagnose atrial fibrillation was only available by prescription.

Since 2013, I have been successfully using this device with my patients who have atrial fibrillation (and writing about it extensively)

Apple COO Jeff Williams standing in front of (presumably) an ECG obtained by Apple Watch 4. It’s OK quality (but smallish p waves). Is that the best they could do? Notice that it is making a diagnosis of sinus rhythm. This PDF can be mailed “to your doctor.”

I was shocked, therefore, to hear the COO of Apple, Jeff Williams, announce that Apple will be offering in its new Apple Watch 4  “the first ECG product offered over the counter directly to consumers.”

This seemed blatantly inaccurate as AliveCor’s device clearly preceded by 4 years Apple’s claim.

Furthermore, AliveCor’s Kardia Band which converts any Apple Watch into a single-lead ECG  (which I’ve written about here and here) has been available and providing the Apple Watch-based ECGs since November 30, 2017.

AliveCor has an outstanding website which documents in detail all the research studies done on their products (there are dozens and dozens of linked papers) and all of their press releases dating back to 2012. It also explains in detail how the product works.

The title of their November 30, 2017 release was  FDA Clears First Medical Device Accessory for Apple Watch®

AliveCor shortly thereafter (December 12, 2017) announced Smart Rhythm , an Apple Watch app that monitors your rhythm and alerts you if it thinks you are in atrial fibrillation. I’ve discussed Smart Rhythm here.

Apple’s Watch will tell you that you are not in atrial fibrillation. Given that we don’t know how accurate it is, should that be reassuring?

The new Apple Watch’s rhythm monitoring app sounds a lot like Smart Rhythm but without any of the documentation AliveCor has provided.

So, within 10 months of Alivecor providing the world with the first ever wearable ECG (and proven its accuracy in afib) Apple seems to have come out with a remarkably similar product.

The major difference between Apple and AliveCor is the total lack of any reviewable data on the accuracy of the Apple device. Yes, that’s right Apple has provided no studies and no data and we have no idea how accurate its ECG device is (or its monitoring algorithm).

For all we know, it could diagnose sinus rhythm with frequent APCS or PVCs consistently as atrial fibrillation, sending thousands of Watch 4 wearers into a panic and overloading the health care system with meaningless alerts.

Apple’s website claims

Apple Watch Series 4 is capable of generating an ECG similar to a single-lead electrocardiogram. It’s a momentous achievement for a wearable device that can provide critical real-time data for doctors and peace of mind for you.

Apple’s “momentous achievement” was actually achieved 10 months earlier by AliveCor and if its monitoring algorithm and ECG system are significantly worse than the proven AliveCor system they will be destroying the peace of mind of users.

Electrodes built into the Digital Crown and the sapphire back crystal allow sensing of cardiac electrical signals. Did Apple get this idea from AliveCor?

After describing the Apple Watch’s new health features, Jeff Williams introduced Ivor Benjamin, MD, the President of the American Heart Association. Benjamin proceeded to describe the new Apple Watch cardiac features as “game-changing”, noting that the AHA is committed to helping patients be “proactive.”

Does  Benjamin have access to the accuracy of the Apple Watch ECG sensor? If so, he and the AHA should immediately share it with the scientific community. If not, by endorsing this feature of the Watch he should be ashamed. Users need to know if he or the AHA was paid any money for this appearance. Also, we should demand to know if (as the prominent AHA logo suggested and news reports implied) the AHA is somehow endorsing the Apple Watch.

Frequent readers know I’m a huge Apple fan but this Apple Watch business makes me think something is rotten in the state of Apple.

Skeptically Yours,

-ACP