Heart rate monitors are part and parcel of smartwatches and fitness trackers now, but nowadays an electrocardiogram (ECG/EKG) is a staple of health wearables.
The technology is designed to help people keep closer tabs on their heart health, and is used to help identify atrial fibrillation (Afib) a serious medical condition that is a leading cause of stroke.
ECG was thrust into the wearable spotlight via the Apple Watch Series 4, but it can now be found on smartwatches from Samsung, Google, Fitbit and even Huawei and Garmin.
What is ECG and why is it a useful feature to have on a smartwatch? We get into all of the key details below.
What is ECG?
Most wearables have optical heart rate monitors, which use flashing LEDs to penetrate the skin and detect blood flow. When light is reflected off the flow of blood, it’s captured by the sensors. The algorithm then gets to work to turn that into an estimation of your heart rate.
But it’s not as accurate as it could be – especially where medical issues are involved.
Enter the electrocardiogram (ECG or EKG). Rather than measuring blood flow, it’s designed to measure how well your heart is working.
It’s a term you’d more commonly hear in the medical industry, referring to an electrocardiograph that's used to detect cardiac abnormalities.
Why would I buy an ECG smartwatch?
An ECG smartwatch can detect if you have atrial fibrillation, a condition that causes an irregular heart rate and is a leading cause of strokes.
Taking an ECG reading on your watch can tell you if you have a healthy heart rhythm – but for many people, the feature is something you'll likely use once and then forget about.
But for a large subset of people, having ECG capabilities can be hugely beneficial.
Smartwatches from the likes of Apple and Fitbit can export an ECG graph of your heart rate, which can be a huge help when talking to your doctor.
“ECG on wearables is super high value for a small segment. It is probably going to be more advantageous to our users over 50 than 20-year-olds, but we're trying to build something for everybody," Dr. Conor Heneghan, Director of Research Algorithms at Fitbit told Wareable.
"Afib can come and go, as can conditions that affect the rhythm of your heart. That means having a device that can take spot readings at any time, makes it a hugely powerful health tool to have at your disposal," he said.
How do ECG smartwatches work?
Most watches have a built-in ECG sensor, that can take a spot reading of your heart rate rhythm.
You start the app and then place your finger on a specific part of the watch (usually the case or crown) for the duration of the test.
Fitbit has recently launched a new feature that continuously monitors heart rate rhythms, and can look for atrial fibrillation using the PPG sensor.
While this has an advantage over ECG watches for spotting Afib, ECG smartwatches offer the benefit of being able to export a graph of your heart rate rhythm.
Which smartwatches have ECG?
The list of smartwatches that currently include an ECG is the following:
- Apple Watch Series 4
- Apple Watch Series 5
- Apple Watch Series 6
- Apple Watch Series 7
- Apple Watch Series 8
- Apple Watch Ultra
- Samsung Galaxy Watch 5
- Samsung Galaxy Watch 4
- Samsung Galaxy Watch Active 2
- Samsung Galaxy Watch 3
- Google Pixel Watch
- Fitbit Sense
- Fitbit Sense 2
- Fitbit Charge 5
- Garmin Venu 2 Plus
- Withings ScanWatch
- Withings Move ECG
- Coros Vertix 2
- Coros Apex 2/Apex 2 Pro
- Amazfit Smartwatch 2
ECG wearables available today
Apple Watch Series 4 - Series 8
The latestApple Watch Series 8 (and the Series 4, 5, 6, 7) has ECG functionality, with sensors built into the ceramic heart rate monitor under the watch, and also the Digital Crown.
Fire up the ECG app, pop your finger on the crown and you'll be guided through the reading.
You'll get a notification of whether the reading was normal or Afib, and an EKG graph of your heart rate will be logged in the Apple Health smartwatch app, which can be downloaded and shared with your doctor.
Apple has FDA approval for its ECG, as well as clearance in the European Economic Area with more than 20 countries now able to make use of the health feature.
- How to use the Apple Watch ECG feature
Fitbit Sense 2
The Fitbit Sense 2 is the company's first health watch, and it brings a host of new sensors including ECG.
You can perform ECG spot checks using the app on the watch. When you open the app, touch your fingers to the aluminum case and hold as instructed on the watch for an ECG to be taken.
Again, this can be exported via a PDF.
The PPG sensor also scans for abnormal rhythms continuously, including high and low heart rates. That means it can alert you to possible issues without the need to take manual scans, and if you suffer from a condition, you can better understand potential triggers.
The Fitbit ECG sensor has gained full FDA and CE approval for use in the US and Europe.
Fitbit Charge 5
Staying with Fitbit, the company has launched the ECG feature on its new Charge 5 fitness tracker.
It's the only fitness tracker form factor that can take an ECG reading – so a good option for those who don't want to wear a smartwatch.You pinch the sides of the case to take the reading, which is delivered to the Fitbit app.
You can also share your results with your doctor, as well as get immediate feedback on whether your heart rhythm is normal or Afib.
Read our full Fitbit Charge 5 review.
Samsung Galaxy Watch 5
The Galaxy Watch 5 is the latest and greatest Samsung smartwatch in town – and the move to Wear OS hasn't affected its ability to take an ECG measurement.
The ECG app can be found on the Galaxy Watch 5 or 5 Pro, just as it was on the Galaxy Watch 4 and Watch 4 Classic.
It takes a 30-second reading when you place your finger on the sensor built into the top physical button. You'll also need to remain still with your forearm resting on a flat surface.
Samsung's Health Monitor app is live in the US and South Korea, and it's also received clearance in Europe.
Specifically, it's available in Iceland, Germany, Bulgaria, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Hungary, Ireland, Italy, Latvia, Belgium, Lithuania, Netherlands, Greece, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Austria, and the United Kingdom.
What's more, Japan, Indonesia, UAE, Chile, India, and China are all confirmed, too.
Have a read of our full Samsung Galaxy Watch 5 review and our guide on how to take an ECG reading on Samsung smartwatches.
Huawei Watch D
It's taken a while but the Huawei Watch D is now available in Europe – and it features blood pressure monitoring and ECG detection.
The Watch D is the company's health smartwatch, and it's a big, powerful beast. It's certainly not a comfortable, sleek smartwatch for casual wear, but as we discovered in our Huawei Watch D review, it's an effective heath smartwatch.
This is a device that's designed for medical-grade surveillance of your vitals, and it's likely suited to those that have a pre-existing condition.
As with all things Huawei, it's unlikely we see a release for this one in the US.
Google Pixel Watch
It's not just Fitbit's devices that Google enlists to take electrocardiograms, with the debut Pixel Watch also offering the skill.
Like with the Apple Watch, this is taken through the crown on the outer edge of the watch through a 30-second scan.
Results are then sent to the Fitbit app for your perusal, with a full history and timeline of your readings shown.
Read our Google Pixel Watch review for the full details.
Garmin Venu 2 Plus
Out of no-where, Garmin has joined the ECG smartwatch fray, and already has a smartwatch in the game.
The company's ECG tech was green-lit by the FDA, and the Garmin Venu 2 Plus, which was launched in 2022, was updated to enable the feature.
It's the company's only ECG smartwatch for now, but you can bet that forthcoming releases in 2023 will have the sensor built in.
Users place their index finger and thumb on the metal edge of the device's bezel for 30 seconds in order to receive a reading.
You'll need to set it all up in Garmin Connect first, though, which will also be a hub for historical data, as well as the place you can export individual readings as PDFs.
The Withings ScanWatch offers even more sensors, with SpO2 detection of sleep apnea also on board.
You can take off-the-cuff ECG readings to check for afib, and the results can be presented in a PDF to show to your doctor.
The optical heart rate sensor that checks your heart rate throughout the day will also keep an eye out for irregular heartbeats, and if it thinks you may have them, suggest you take an ECG test.
ScanWatch has been out in the EU since 2020 and is now available in the US. That's great news, as it's an excellent health wearable – and it's heading for a much bigger audience.
Check out our Withings ScanWatch review.
Withings Move ECG
The first hybrid watch to feature the ability to take an electrocardiogram reading – helping detect the signs of atrial fibrillation – the Move ECG is also water resistant up to 50 meters and will automatically track your activity.
Unfortunately, this one is currently still undergoing clinical validation from the FDA in the US, though it is available in the EU already.
Read our full Withings Move ECG review.
Coros Vertix 2 / Apex 2
You may not have heard of Coros, but it's a US-based fitness wearables brand that has Garmin in its sights
The Vertix 2 is the company's new outdoors GPS watch, which offers an enormous 140 hours of GPS battery life, mapping and training insights.
But up its sleeve is an ECG sensor – but it's not used to take the same type of Afib readings as the other devices in our list.
However, it's not a health feature, like we've seen on other smartwatches. The Coros sensor is designed to be a more accurate check of heart rate variability, which is used to calculate your recovery after workouts. Poor HRV scores can also indicate stress, overtraining or alcohol intake.
HRV scores are commonplace in fitness wearables, but are usually measured via the PPG sensor during sleep.
Read our Coros Vertix 2 review.
How does ECG smartwatch tech work?
An ECG records the tiny electrical signals that are generated by the beating of your heart under your skin, which it presents as a trace. This then allows trained professionals, machines, or wearables to understand more about how your heart is functioning – and determine if there are any abnormalities.
“In the simplest sense, it can tell you the heart rate (how fast), the rhythm (how regular), the state of the conduction system and muscle tissue (heart attacks), and even the level of certain chemicals like potassium in the blood, and the effect of medication,” says Dr. Keith Grimes, GP and Clinical Innovation Director at Babylon Health.
An electrocardiograph in a medical setting usually requires placing electrodes on the skin situated close to the heart, which measures electrical activity produced by the heart as it contracts. The electrical activity is sent to a receiver that records the information, and this is where the heart's rhythm can be analyzed and irregularities can be detected.
But the tech inside the Apple Watch (and other ECG-reading devices you can use at home) works differently.
For example, rather than place electrodes on your skin, the Apple Watch example requires you to hold your finger on the device’s digital crown. Wait for 30 seconds and the electrical activity of your heart draws a red trace across the watch’s screen. Once you’re done, the app will let you know whether the trace captured a normal heartbeat, called a sinus rhythm, or an abnormal heartbeat.
On the Fitbit Sense, when you've opened its ECG app you'll be prompted to place your fingers on the corners of the watch's frame for the same 30 seconds to take a reading. It will then indicate whether you have a normal sinus rhythm, or whether there are signs that you might have atrial fibrillation or just an inconclusive reading.
Samsung's ECG-packing smartwatches use their touch-sensitive button as a sensor that you'll place your finger on for 30 seconds as well. After that, it will measure your heart rate and rhythm, and classify it as sinus rhythm (normal) or AFib.
The biggest difference between an electrocardiograph at a hospital and the ECG tech in your Apple, Fitbit, or Samsung smartwatch is the first is a 12 lead and the latter is a single lead. In the simplest terms, the 12 lead is taking lots of readings about your heart – the single lead is taking one.
That means a single lead ECG has limited capabilities and offers a single view of your heart. It can’t be relied upon to detect all heart rhythm abnormalities – or worsening heart problems. It also can’t be relied upon to detect the electrical changes that take place during a heart attack or abnormal heart structure.
Apple makes this clear, but it’s important to differentiate between what an ECG at the hospital can offer and what tech you use at home can offer.
How can ECG tech save your life?
An ECG carried out by a medical professional can identify many issues with your heart. But ECG devices designed to be used at home aren’t quite there yet.
Here are a few of the ways the ECG tech found in your Apple Watch or Samsung smartwatch can currently save your life though, including the problems that they can identify and the others they might be able to.
Atrial fibrillation is a heart condition that can cause irregular and abnormally fast heartbeat. It’s common and potentially deadly. It's also intermittent, which makes it difficult to detect. This is the one condition that both Apple and Samsung are FDA-cleared to detect. FDA approval is still pending for Fitbit's new Sense watch to do the same.
ZDNet writer Jason Perlow was part of the early testing of Apple’s Atrial fibrillation detection and identified a problem with his heart in 2018 thanks to the data that was collected.
The reason personal devices are effective at recognizing this particular kind of arrhythmia (irregular heartbeat), and the reason Perlow cites for its effectiveness in his case, is because you can take them at any time.
Unlike getting an ECG at the hospital, you can monitor your heart throughout the day. “Irregularities in heart rate can be episodic, and difficult to capture,” explains Dr. Grimes, “So a personal ECG that you carry with you can help clinicians record when palpitations happen and help with diagnosis.”
This means you can take a 30-second ECG whenever you feel symptoms and also better understand the context of what may have brought them on. For example, if you just got back from a run and you’re feeling a bit off.
Dr. Tony Faranesh, a senior research scientist at Fitbit says the optimal way to identify atrial fibrillation through heart rate tracking is to screen while at rest, making sleep ideal for detection.
On Fitbit's devices, that's done by using its optical-based PPG heart rate sensor. The ECG sensor, like Apple and Samsung, is used for spot checks.
Like Apple, it seems that Fitbit won't be continually scanning for signs of Afib. Though Apple and Fitbit both use the PPG sensor to check for irregular rhythms such as high or low heart rate.
Dr. Julia Reynolds, Associate Director at Innovation Agency, tells us that the Kardia Mobile built by startup AliveCor is sometimes even prescribed to patients for this exact reason.
“Individuals may be given a mobile ECG device by their health professional if they are concerned they may have paroxysmal Atrial fibrillation – that’s when it comes and goes. That way, if they are feeling signs and symptoms, they can take their ECG when they are experiencing symptoms.”
How often should I take an ECG reading?
Provided your heart gets a normal sinus rhythm, you’re likely to only need to periodically take an ECG test, just to check everything is in order.
But if you suffer from the feeling of your heart racing, palpitations, or periods of feeling unwell, then you can use the ECG app as and when you need it. And it becomes an incredibly important health tool, right on your wrist.
Fitbit’s Director of Research Algorithms, Conor Heneghan, says that means users can have a better-informed conversation with their doctor.
“The problem with cardiac issues with rhythm is they're so intermittent,” said Heneghan.
“For people who have palpitations or other symptoms, ECG can be a reassurance. And if they feel like something's a bit odd going on physiologically they can capture that moment to speak with their doctor about it,” he continued.
Fitbit also recommends that the ECG feature should only be used by those aged 22 or above.
The problems with false positives – and negatives
ECG devices available to consumers can detect a range of heart problems, whether they’ve been cleared to or not, but that doesn’t mean they should replace a trip to your doctor.
“Reading an ECG is tricky,” Dr. Grimes explains. “Current technology uses machine learning to detect common abnormalities, but personal ECG, like the kind you find on the Apple Watch, is not as accurate as medical devices.”
Personal ECG devices are proven to save lives, but on the flip side they can still miss major problems or cause people to worry they have issues with their heart when they don’t. Dr. Grimes calls these “false negatives” and “false positives”.
Although many in the medical profession are warning people to be wary of the results they get from their Apple Watch or other ECG device, having more control over our health at home is going to become more widespread over time.
That means instead of advising against ECG devices, people need to be informed that readings might not always be accurate – but it’s best to head to a medical professional if you see a reading you’re concerned about, to get it checked out.
The ECG technology in a smartwatch uses LEDs flashed against your skin to detect blood flow and measure your heart rate. Sensors collect this information and algorithms process it to make sense of your heart's rhythm.What is the best wearable to monitor heart health? ›
The Fitbit Versa 4 tops this list due to its overwhelmingly positive reviews and variety of features, including 24/7 heart rate tracking that's displayed directly on its home screen. calories burned.
Apple Watch Series 8
It has a number of health-tracking features, including an optical heart sensor, an electrical heart sensor for ECG, a blood oxygen sensor and a new body temperature sensor. You can tap into yoga, meditation and other workout programs via Apple Fitness+.
|boAt Xtend Smart Watch||4.2 / 5||Rs. 2,299|
|Noise ColorFit Pro 4 Advanced Bluetooth Calling Smart Watch||4.1 / 5||Rs. 2,999|
|Fitbit Sense Advanced Smartwatch||4.0 / 5||Rs. 17,975|
|Apple Watch Series 8 [GPS 41 mm] Smart Watch||4.6 / 5||Rs. 43,605|
A user places a single finger on each of the electrodes for 30 s. The detector then sends the data via Bluetooth to the user's smartphone where the ECG Check app renders the data as a single ECG lead and is most similar to lead I on a conventional 12-lead ECG.How accurate is ECG? ›
An ECG is pretty accurate at diagnosing many types of heart disease, although it doesn't always pick up every heart problem. You may have a perfectly normal ECG, yet still have a heart condition.Can smartwatches detect heart problems? ›
What Can a Smartwatch Do for Your Heart Health? Key takeaways: Some newer-generation smartwatches can track heart rate and blood pressure. Except for atrial fibrillation (available in some models), smartwatches can't diagnose serious heart problems, like heart attack, stroke, or heart failure.What is the most accurate smartwatch for health monitoring? ›
- Fitbit Versa 4 Fitness Smartwatch.
- Samsung Galaxy Watch5 Pro.
- Apple Watch Series 8 (GPS 45mm) Smartwatch.
- Garmin Venu 2.
- Garmin fēnix 7 Solar Multisport GPS Watch.
- Garmin Vivomove Trend.
- Fitbit Inspire 2 Health and Fitness Tracker.
ECG patches are small, extremely portable devices that are attached to the body. They are used to receive and transmit electrical signals of the user's heart activity. How do they work? A wearable ECG patch is equipped with an electrocardiography sensor and accelerometer to detect and record physiological data.Are smart watch heart monitors accurate? ›
While there are factors that can reduce the accuracy of wrist HR monitors, they are generally considered to be accurate enough for most healthy runners. Errors are usually arounds 5% or 3 beats per minute.
How smartwatches detect abnormal heart rhythms. Smartwatches and sensors provide information about heart rate and rhythm. One of the most common abnormal rhythms detected by personal devices is atrial fibrillation (AFib), an irregular rhythm in the upper chambers of the heart.Can smart watches detect heart problems? ›
What Can a Smartwatch Do for Your Heart Health? Key takeaways: Some newer-generation smartwatches can track heart rate and blood pressure. Except for atrial fibrillation (available in some models), smartwatches can't diagnose serious heart problems, like heart attack, stroke, or heart failure.Does heart failure show on ECG? ›
Electrocardiogram (ECG or EKG) to assess the heart rate and rhythm. This test can often detect heart disease, heart attack, an enlarged heart, or abnormal heart rhythms that may cause heart failure.