Apple Watch Able to Detect Abnormal Heart Rhythm With 97% Accuracy
The Apple Watch's built-in heart rate monitor is 97 percent accurate when detecting the most common form of an abnormal heart rhythm when paired with an algorithm to sort through the data, according to a new study conducted by the University of California, San Francisco and the team behind the Cardiogram app (via TechCrunch).
There were 6,158 participants in the study, all of whom used the Cardiogram app on the Apple Watch to monitor their heart rate. Most were known to have normal EKG readings, but 200 suffer from paroxysmal atrial fibrillation (an occasional irregular heartbeat).
Data from these participants, along with data taken from normal Cardiogram users, was used to build a neural network that could recognize the abnormal heart rhythms solely from data collected by the Apple Watch. As of today, Cardiogram says its algorithm can almost always successfully determine when a patient is in atrial fibrillation.
In order to validate the model, we obtained gold-standard labels of atrial fibrillation from cardioversions. In a cardioversion, a patient experiencing atrial fibrillation is converted back to normal sinus rhythm, either chemically or with a shock to the heart. 51 patients at UCSF agreed to wear an Apple Watch during their cardioversion.
We obtained heart rate samples before the procedure, when the patient was in atrial fibrillation, and after, when patient's heart was restored to a normal rhythm. On this validation set, our model performed with an AUC of 0.97, beating existing methods.
Cardiogram is a startup that's aiming to garner more information from the data collected by the Apple Watch. The study, which Cardiogram has raised funding for, started in March of 2016 and will continue as UCSF and Cardiogram work to refine the neural network and detect other conditions beyond atrial fibrillation.
Cardiogram plans to put in additional work before using its algorithm to start notifying Cardiogram users of arrhythmias. The company needs to conduct further testing to make sure the algorithm works in a variety of conditions and it needs to work on scaling it so it can be used continuously by all Cardiogram users.
The Cardiogram app can be downloaded from the App Store for free. [Direct Link]
Popular Stories
Apple is not expected to release a standard iPhone 18 model this year, according to a growing number of reports that suggest the company is planning a significant change to its long-standing annual iPhone launch cycle.
Despite the immense success of the iPhone 17 in 2025, the iPhone 18 is not expected to arrive until the spring of 2027, leaving the iPhone 17 in the lineup as the latest...
Language learning app Duolingo has apparently been using the iPhone's Live Activity feature to display ads on the Lock Screen and the Dynamic Island, which violates Apple's design guidelines.
According to multiple reports on Reddit, the Duolingo app has been displaying an ad for a "Super offer," which is Duolingo's paid subscription option.
Apple's guidelines for Live Activity state that...
The company behind the BlackBerry-like Clicks Keyboard accessory for the iPhone today unveiled a new Android 16 smartphone called the Clicks Communicator.
The purpose-built device is designed to be used as a second phone alongside your iPhone, with the intended focus being communication over content consumption. It runs a custom Android launcher that offers a curated selection of messaging...
Apple is planning to release a low-cost MacBook in 2026, which will apparently compete with more affordable Chromebooks and Windows PCs. Apple's most affordable Mac right now is the $999 MacBook Air, and the upcoming low-cost MacBook is expected to be cheaper. Here's what we know about the low-cost MacBook so far.
Size
Rumors suggest the low-cost MacBook will have a display that's around 13 ...
Apple plans to introduce a 12.9-inch MacBook in spring 2026, according to TrendForce.
In a press release this week, the Taiwanese research firm said this MacBook will be aimed at the entry-level to mid-range market, with "competitive pricing."
TrendForce did not share any further details about this MacBook, but the information that it shared lines up with several rumors about a more...
Apple today announced a number of updates to Apple Fitness+ and activity with the Apple Watch.
The key announcements include:
New Year limited-edition award: Users can win the award by closing all three Activity Rings for seven days in a row in January.
"Quit Quitting" Strava challenge: Available in Strava throughout January, users who log 12 workouts anytime in the month will win an ...
Govee today introduced three new HomeKit-compatible lighting products, including the Govee Floor Lamp 3, the Govee Ceiling Light Ultra, and the Govee Sky Ceiling Light.
The Govee Floor Lamp 3 is the successor to the Floor Lamp 2, and it offers Matter integration with the option to connect to HomeKit. The Floor Lamp 3 offers an upgraded LuminBlend+ lighting system that can reproduce 281...
Belkin today announced a range of new charging and connectivity accessories at CES 2026, expanding its portfolio of products aimed at Apple device users.
UltraCharge Pro Power Bank 10K with Magnetic Ring
The lineup includes new Qi2 and Qi2.2 wireless chargers, magnetic power banks, a high-capacity laptop battery, and USB-C productivity accessories, with an emphasis on higher charging...
