ECG smartwatches explained: How they work and the best on the market

Coronary heart price displays are half and parcel of smartwatches and health trackers now, however electrocardiogram (ECG/EKG) is the brand new sensor on the town.

The know-how is designed to assist individuals preserve nearer tabs on their coronary heart well being, and may even be used to assist establish atrial fibrillation (Afib) a critical medical situation that could be a main explanation for stroke.

ECG was thrust into the wearable highlight by way of the Apple Watch Collection 4, however it might probably now be discovered on smartwatches from Samsung, Google, Fitbit and even Huawei.

What’s ECG and why is it a helpful characteristic to have on a smartwatch? We get into the entire key particulars under.

What’s ECG?

Most wearables have optical coronary heart price displays, which use flashing LEDs to penetrate the pores and skin and detect blood circulate. When gentle is mirrored off the circulate of blood, it’s captured by the sensors. The algorithm then will get to work to show that into an estimation of your coronary heart price.

Nevertheless it’s not as correct because it may very well be – particularly the place medical points are concerned.

Enter the electrocardiogram (ECG or EKG). Quite than measuring blood circulate, it’s designed to measure how properly your coronary heart is working.

It’s a time period you’d extra generally hear within the medical business, referring to an electrocardiograph that is used to detect cardiac abnormalities.

Why would I purchase an ECG smartwatch?

An ECG smartwatch can detect in case you have atrial fibrillation, a situation that causes an irregular coronary heart price and is a number one explanation for strokes.

Taking an ECG studying in your watch can let you know in case you have a wholesome coronary heart rhythm – however for many individuals, the characteristic is one thing you may probably use as soon as after which overlook about.

However for a big subset of individuals, having ECG capabilities might be vastly helpful.

Smartwatches from the likes of Apple and Fitbit can export an ECG graph of your coronary heart price, which is usually a big assist when speaking to your physician.

“ECG on wearables is tremendous excessive worth for a small section. It’s in all probability going to be extra advantageous to our customers over 50 than 20-year-olds, however we’re making an attempt to construct one thing for everyone,” Dr. Conor Heneghan, Director of Analysis Algorithms at Fitbit instructed Wareable.

“Afib can come and go, as can circumstances that have an effect on the rhythm of your coronary heart. Which means having a tool that may take spot readings at any time, makes it a vastly highly effective well being instrument to have at your disposal,” he stated.

How do ECG smartwatches work?

Most watches have a built-in ECG sensor, that may take a spot studying of your coronary heart price rhythm.

You begin the app after which place your finger on a particular a part of the watch (normally the case or crown) throughout the take a look at.

Fitbit has not too long ago launched a brand new characteristic that repeatedly displays coronary heart price rhythms, and may search for atrial fibrillation utilizing the PPG sensor.

Whereas this has a bonus over ECG watches for recognizing Afib, ECG smartwatches provide the advantage of with the ability to export a graph of your coronary heart price rhythm.

Which smartwatches have ECG?


The listing of smartwatches that presently embody an ECG is the next:

ECG wearables out there right this moment

Apple Watch Collection 4 – Collection 8

Value when reviewed: $399 / £429


The most recent Apple Watch Series 8 (and the Collection 4, 5, 6, 7) has ECG performance, with sensors constructed into the ceramic coronary heart price monitor below the watch, and in addition the Digital Crown.

Hearth up the ECG app, pop your finger on the crown and you will be guided via the studying.

You will get a notification of whether or not the studying was regular or Afib, and an EKG graph of your coronary heart price will probably be logged within the Apple Well being smartwatch app, which might be downloaded and shared together with your physician.

Apple has FDA approval for its ECG, in addition to clearance within the European Financial Space with greater than 20 international locations now capable of make use of the well being characteristic.

Fitbit Sense 2

Value when reviewed: $329 / £299


The Fitbit Sense 2 is the corporate’s first well being watch, and it brings a number of latest sensors together with ECG.

You may carry out ECG spot checks utilizing the app on the watch. If you open the app, contact your fingers to the aluminum case and maintain as instructed on the look ahead to an ECG to be taken.

Once more, this may be exported by way of a PDF.

The PPG sensor additionally scans for irregular rhythms repeatedly, together with excessive and low coronary heart charges. Which means it might probably warn you to potential points with out the necessity to take handbook scans, and in the event you undergo from a situation, you’ll be able to higher perceive potential triggers.

The Fitbit ECG sensor has gained full FDA and CE approval to be used within the US and Europe.

Fitbit Cost 5

Value when reviewed: $279.99 / £269.99


Staying with Fitbit, the corporate has launched the ECG characteristic on its new Cost 5 health tracker.

It is the one health tracker type issue that may take an ECG studying – so a very good possibility for many who do not need to put on a smartwatch. You pinch the edges of the case to take the studying, which is delivered to the Fitbit app.

You can even share your outcomes together with your physician, in addition to get fast suggestions on whether or not your coronary heart rhythm is regular or Afib.

Learn our full Fitbit Charge 5 review.

Samsung Galaxy Watch 5

Value when reviewed: $299.99 / £269.99

ECG smartwatches explained: How they work and the best on the market

The Galaxy Watch 5 is the most recent and biggest Samsung smartwatch on the town – and the transfer to Put on OS hasn’t affected its capacity to take an ECG measurement.

The ECG app might be discovered on the Galaxy Watch 5 or 5 Professional, simply because it was on the Galaxy Watch 4 and Watch 4 Traditional.

It takes a 30-second studying while you place your finger on the sensor constructed into the highest bodily button. You will additionally want to stay nonetheless together with your forearm resting on a flat floor.

Samsung’s Well being Monitor app is reside within the US and South Korea, and it is also obtained clearance in Europe.

Particularly, it is out there in Iceland, Germany, Bulgaria, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Hungary, Eire, Italy, Latvia, Belgium, Lithuania, Netherlands, Greece, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Austria, and the UK.

What’s extra, Japan, Indonesia, UAE, Chile, India, and China are all confirmed, too.

Have a learn of our full Samsung Galaxy Watch 5 review and our information on how to take an ECG reading on Samsung smartwatches.

Huawei Watch D

Value when reviewed: £349.99

ECG smartwatches explained: How they work and the best on the market

It is taken some time however the Huawei Watch D is now out there in Europe – and it options blood strain monitoring and ECG detection.

The Watch D is the corporate’s well being smartwatch, and it is a huge, highly effective beast. We used it at IFA 2022, and it is definitely not a snug, glossy smartwatch for informal put on.

It is a machine that is designed for medical-grade surveillance, and it is probably suited to people who have a pre-existing situation.

As with all issues Huawei, it is unlikely we see a launch for this one within the US. 

Google Pixel Watch

Value when reviewed: $349 / £339

It isn’t simply Fitbit’s gadgets that Google enlists to take electrocardiograms, with the debut Pixel Watch additionally providing the ability. 

Like with the Apple Watch, that is taken via the crown on the outer fringe of the watch via a 30-second scan. 

Outcomes are then despatched to the Fitbit app to your perusal, with a full historical past and timeline of your readings proven.

Learn our Google Pixel Watch review for the complete particulars.

Withings ScanWatch

Value when reviewed: $249 / £229


The Withings ScanWatch gives much more sensors, with SpO2 detection of sleep apnea additionally on board.

You may take off-the-cuff ECG readings to test for afib, and the outcomes might be offered in a PDF to indicate to your physician.

The optical coronary heart price sensor that checks your coronary heart price all through the day can even preserve an eye fixed out for irregular heartbeats, and if it thinks you could have them, counsel you are taking an ECG take a look at.

ScanWatch has been out within the EU since 2020 and is now out there within the US. That is nice information, because it’s a superb well being wearable – and it is heading for a a lot greater viewers.

Take a look at our Withings ScanWatch review.

Withings Transfer ECG

Value when reviewed: $129 / £129


The primary hybrid watch to characteristic the flexibility to take an electrocardiogram studying – serving to detect the indicators of atrial fibrillation – the Transfer ECG can also be water-resistant as much as 50 meters and can mechanically observe your exercise.

Sadly, this one is presently nonetheless present process scientific validation from the FDA within the US, although it’s out there within the EU already.

Learn our full Withings Move ECG review.

Coros Vertix 2

Value when reviewed: $699 / $599


You might not have heard of Coros, but it surely’s a US-based health wearables model that has Garmin in its sights

The Vertix 2 is the corporate’s new open air GPS watch, which gives an unlimited 140 hours of GPS battery life, mapping and coaching insights.

However up its sleeve is an ECG sensor – but it surely’s not used to take the identical sort of Afib readings as the opposite gadgets in our listing. It is designed to take coronary heart price variability readings as a stress sensor.

Learn our Coros Vertix 2 review.

Amazfit Verge 2

Obtainable from $145 / £115


Amazfit’s newest and biggest, the Verge 2 packs ECG know-how to put it as a direct competitor for different watches on this listing. This works through the use of Huami’s Huangshan No.1 always-on AI chip.

This nifty chip includes a cardiac biometrics engine to watch your coronary heart price extra precisely, together with screening for coronary heart arrhythmia and atrial fibrillation.

In the intervening time, nevertheless, the Verge 2 is just out there in China, with US and European launches deliberate.

How does ECG smartwatch tech work?

An ECG data the tiny electrical indicators which might be generated by the beating of your coronary heart below your pores and skin, which it presents as a hint. This then permits educated professionals, machines, or wearables to grasp extra about how your coronary heart is functioning – and decide if there are any abnormalities.

“Within the easiest sense, it might probably let you know the center price (how briskly), the rhythm (how common), the state of the conduction system and muscle tissue (coronary heart assaults), and even the extent of sure chemical compounds like potassium within the blood, and the impact of remedy,” says Dr. Keith Grimes, GP and Clinical Innovation Director at Babylon Health.

An electrocardiograph in a medical setting normally requires putting electrodes on the pores and skin located near the center, which measures electrical exercise produced by the center because it contracts. {The electrical} exercise is shipped to a receiver that data the data, and that is the place the center’s rhythm might be analyzed and irregularities might be detected.

However the tech contained in the Apple Watch (and different ECG-reading gadgets you need to use at house) works in another way.


For instance, reasonably than place electrodes in your pores and skin, the Apple Watch instance requires you to carry your finger on the machine’s digital crown. Anticipate 30 seconds and {the electrical} exercise of your coronary heart attracts a purple hint throughout the watch’s display. When you’re accomplished, the app will let whether or not the hint captured a standard heartbeat, known as a sinus rhythm, or an irregular heartbeat.

On the Fitbit Sense, while you’ve opened its ECG app you may be prompted to put your fingers on the corners of the watch’s body for a similar 30 seconds to take a studying. It can then point out whether or not you will have a standard sinus rhythm, or whether or not there are indicators that you just may need atrial fibrillation or simply an inconclusive studying.


Samsung’s ECG-packing smartwatches use their touch-sensitive button as a sensor that you will place your finger on for 30 seconds as properly. After that, it’ll measure your coronary heart price and rhythm, and classify it as sinus rhythm (regular) or AFib.

The most important distinction between an electrocardiograph at a hospital and the ECG tech in your Apple, Fitbit, or Samsung smartwatch is the primary is a 12 lead and the latter is a single lead. Within the easiest phrases, the 12 lead is taking plenty of readings about your coronary heart – the one lead is taking one.

Which means a single lead ECG has restricted capabilities and gives a single view of your coronary heart. It may possibly’t be relied upon to detect all coronary heart rhythm abnormalities – or worsening coronary heart issues. It can also’t be relied upon to detect {the electrical} modifications that happen throughout a coronary heart assault or irregular coronary heart construction.

Apple makes this clear, but it surely’s essential to distinguish between what an ECG on the hospital can provide and what tech you employ at house can provide.

How can ECG tech save your life?


An ECG carried out by a medical skilled can establish many points together with your coronary heart. However ECG gadgets designed for use at house aren’t fairly there but.

Listed here are a number of of the methods the ECG tech present in your Apple Watch or Samsung smartwatch can presently save your life although, together with the issues that they will establish and the others they could be capable of.

Atrial fibrillation

Atrial fibrillation is a coronary heart situation that may trigger irregular and abnormally quick heartbeat. It’s frequent and doubtlessly lethal. It is also intermittent, which makes it tough to detect. That is the one situation that each Apple and Samsung are FDA-cleared to detect. FDA approval continues to be pending for Fitbit’s new Sense watch to do the identical.

ZDNet author Jason Perlow was a part of the early testing of Apple’s Atrial fibrillation detection and recognized an issue along with his coronary heart in 2018 because of the information that was collected.

The rationale private gadgets are efficient at recognizing this specific type of arrhythmia (irregular heartbeat), and the rationale Perlow cites for its effectiveness in his case, is as a result of you’ll be able to take them at any time.

In contrast to getting an ECG on the hospital, you’ll be able to monitor your coronary heart all through the day. “Irregularities in coronary heart price might be episodic, and tough to seize,” explains Dr. Grimes, “So a private ECG that you just carry with you’ll be able to assist clinicians file when palpitations occur and assist with prognosis.”

This implies you’ll be able to take a 30-second ECG everytime you really feel signs and in addition higher perceive the context of what could have introduced them on. For instance, in the event you simply obtained again from a run and also you’re feeling a bit off.

Dr. Tony Faranesh, a senior analysis scientist at Fitbit says the optimum approach to establish atrial fibrillation via coronary heart price monitoring is to display whereas at relaxation, making sleep splendid for detection.

On Fitbit’s gadgets, that is accomplished through the use of its optical-based PPG coronary heart price sensor. The ECG sensor, like Apple and Samsung, is used for spot checks.

Like Apple, it appears that evidently Fitbit will not be regularly scanning for indicators of Afib. Although Apple and Fitbit each use the PPG sensor to test for irregular rhythms akin to excessive or low coronary heart price.

Dr. Julia Reynolds, Associate Director at Innovation Agency, tells us that the Kardia Cellular constructed by startup AliveCor is typically even prescribed to sufferers for this actual purpose.

“People could also be given a cell ECG machine by their well being skilled if they’re involved they might have paroxysmal Atrial fibrillation – that’s when it comes and goes. That manner, if they’re feeling indicators and signs, they will take their ECG when they’re experiencing signs.”

Irregular coronary heart rhythms (arrhythmia)


Neither the Apple Watch 4 nor the KardiaBand are cleared to detect other forms of irregular coronary heart rhythms, however that doesn’t imply they aren’t capable of in the event you or knowledgeable can interpret the information.

The group at AliveCor has been in a position to make use of knowledge from the KardiaBand to detect Lengthy QT Syndrome (LQTS), which is a situation that may trigger an irregular heartbeat and will result in fainting and sudden demise.

“In July 2018, AliveCor introduced a collaboration with Mayo Clinic to develop instruments to facilitate screening for LQTS,” an AliveCor spokesperson says. “Though this characteristic hasn’t but been commercialized, it’s a promising step towards detecting this lethal dysfunction earlier than it’s too late.”

Like Atrial fibrillation, one of many causes private ECG gadgets lend themselves to detecting a situation like LQTS is that it’s usually introduced on via train and stress. Which means even in the event you’ve had an ECG with knowledgeable it may not have been detected. However with the ability to take a studying while you’re out and about, on the health club or exercising may very well be a lifesaver.

Coronary heart assault

An ST-elevation myocardial infarction (STEMI) is a critical coronary heart assault that happens when one of many coronary heart’s main arteries is blocked.

Like LQTS, there’s no official phrase that non-public ECG gadgets can detect a coronary heart assault. However that doesn’t imply AliveCor isn’t utilizing its know-how to strive.

“In November 2018, findings from the STLEUIS Worldwide Multicenter Research counsel {that a} analysis model of AliveCor’s ECG know-how is able to figuring out STEMI,” a spokesperson from AliveCor instructed us.

The research examined a normal 12-lead ECG (just like the one a medical skilled would use) towards a cell ECG and the AliveCor app to search out the cell model was efficient in figuring out STEMI with excessive sensitivity compared to the skilled take a look at.

More healthy insights


Detecting a coronary heart assault or atrial fibrillation may very well be life-saving, however ECG tech may be helpful in serving to us to color a extra correct image of our well being and health.

QardioCore is a chest-based ECG monitor that, in contrast to the Apple Watch, might be worn all through the day amassing greater than 20 million knowledge factors. Though it might probably additionally detect coronary heart rhythm irregularities, its design makes it splendid for many who are in health coaching and wish extra dependable suggestions when coronary heart price exercise fluctuates.

Mixed with readings about physique temperature, respiration price, and stress ranges, an ECG measurement can be utilized to search out out extra about your physique and the way it responds to train than ever earlier than at house.

For these critical about athletic coaching, that is accomplished via Coronary heart Fee Variability (HRV) and a Root Imply Sq. of the Successive Variations (RMSDD) measurement, which identifies the time between peaks and troughs in your heartbeat and lets you practice smarter.

How usually ought to I take an ECG studying?

Supplied your coronary heart will get a standard sinus rhythm, you’re prone to solely must periodically take an ECG take a look at, simply to test every thing is so as.

However in the event you undergo from the sensation of your coronary heart racing, palpitations, or durations of feeling unwell, then you need to use the ECG app as and while you want it. And it turns into an extremely essential well being instrument, proper in your wrist.

Fitbit’s Director of Analysis Algorithms, Conor Heneghan, says meaning customers can have a better-informed dialog with their physician.

“The issue with cardiac points with rhythm is that they’re so intermittent,” stated Heneghan.

“For individuals who have palpitations or different signs, ECG is usually a reassurance. And in the event that they really feel like one thing’s a bit odd occurring physiologically they will seize that second to talk with their physician about it,” he continued.

Fitbit additionally recommends that the ECG characteristic ought to solely be utilized by these aged 22 or above.

The issues with false positives – and negatives

ECG gadgets out there to shoppers can detect a spread of coronary heart issues, whether or not they’ve been cleared to or not, however that doesn’t imply they need to exchange a visit to your physician.

“Studying an ECG is hard,” Dr. Grimes explains. “Present know-how makes use of machine studying to detect frequent abnormalities, however private ECG, like the sort you discover on the Apple Watch, shouldn’t be as correct as medical gadgets.”

Private ECG gadgets are confirmed to save lots of lives, however on the flip aspect they will nonetheless miss main issues or trigger individuals to fret they’ve points with their coronary heart once they don’t. Dr. Grimes calls these “false negatives” and “false positives”.

Though many within the medical career are warning individuals to be cautious of the outcomes they get from their Apple Watch or different ECG machine, having extra management over our well being at house goes to turn out to be extra widespread over time.

Which means as a substitute of advising towards ECG gadgets, individuals should be knowledgeable that readings may not at all times be correct – but it surely’s greatest to move to a medical skilled in the event you see a studying you’re involved about, to get it checked out.


Leave a Reply

Your email address will not be published. Required fields are marked *