Can a smartwatch detect AFib? The honest answer: a handful of ECG-capable smartwatches, including several REXQU models, can flag an irregular heart rhythm consistent with atrial fibrillation and record a single-lead ECG trace you can bring to a doctor. What they can’t do is diagnose you. Think of an on-wrist ECG as an early screening tool, not a substitute for a 12-lead ECG in a clinic.
How ECG Smartwatches Actually Work
Most fitness bands estimate your heart rate using an optical sensor (PPG) that shines light through your skin and watches blood flow. It’s useful for trends, but it isn’t an electrocardiogram. An ECG-capable watch, like REXQU’s Infinity Pro, adds a real electrode — usually built into the bezel or crown — so that when you rest a finger on it, the watch reads the electrical signal your heart actually produces, the same basic principle behind a hospital electrocardiogram, just condensed into a single lead instead of twelve.
A 30- to 60-second reading is enough for the watch’s software to plot a waveform and flag whether the rhythm looks regular, irregular, or inconclusive. That’s genuinely useful information — it just isn’t a diagnosis.
Can a Smartwatch Detect AFib? What the Research Says
This is where the question gets interesting. Large studies, including Apple’s own Heart Study and independent systematic reviews of consumer ECG devices, have found single-lead smartwatch ECGs can be quite good at flagging irregular rhythms when a reading is clean — sensitivity for AFib detection has been reported in the 90%+ range in several trials. But accuracy drops with motion, a loose finger placement, or existing heart conditions that produce unusual waveforms, and false positives do happen. Healthline’s review of the research is a good plain-language summary if you want the details behind the headline numbers.
The practical takeaway: a smartwatch is a reasonable first alert if you notice symptoms like a racing or fluttering heartbeat, but a flagged reading is a reason to call your doctor, not a reason to self-diagnose.
REXQU’s ECG Watches, Compared
REXQU’s ECG & heart health lineup covers a few different approaches to on-wrist heart monitoring, depending on how you want the data:
| Model | ECG Style | Extra Detail | Price |
|---|---|---|---|
| Infinity Pro | On-wrist ECG with rhythm summary | 60-second full health check (BP, SpO2, temperature) | $169.97 |
| CardioSense | 30-second ECG | Extra-large display, one-tap readings | $159.97 |
| PulseBand | On-band ECG, screenless | 25–30 day battery, no subscription | $139.97 |
If you want the most detail in one sitting, Infinity Pro’s rhythm summary paired with its 60-second health check gives you ECG data alongside blood pressure and oxygen in a single tap. If you’d rather keep things simple, CardioSense’s larger display makes the waveform easier to read at a glance.
What an ECG Smartwatch Can’t Do
None of REXQU’s watches — or any consumer smartwatch on the market — are cleared as a diagnostic medical device. They’re wellness tools designed to help you notice patterns and start a conversation with a healthcare provider, not to replace one. If you have a family history of heart disease, existing arrhythmia, or new symptoms like chest pain, dizziness, or shortness of breath, see a doctor regardless of what your watch shows.
Getting a Reliable Reading
A few habits improve reading quality. Sit still with your arm resting on a table rather than taking a reading mid-walk — motion is the biggest cause of an inconclusive result. Use a light, steady finger touch rather than pressing hard, and let the reading run the full 30 to 60 seconds. If a reading comes back inconclusive, just try again; a second attempt resolves most of them.
Can a Smartwatch Detect AFib Without Symptoms?
Yes — that’s actually one of the more useful cases. AFib can be intermittent and symptom-free, which is why an occasional on-demand ECG habit (say, once a week, or whenever something feels slightly off) catches more than only testing when you already feel unwell. It won’t catch every episode, since AFib can come and go between readings, but a habit of regular checks improves your odds of noticing something worth flagging to a doctor.
Bottom Line
So, can a smartwatch detect AFib? For a lot of people, yes — a clean ECG reading from a device like Infinity Pro or CardioSense can catch an irregular rhythm worth mentioning to a doctor. But it’s a screening signal, not a verdict. Pair it with regular checkups, and treat every flagged reading as a prompt to get checked, not a finished diagnosis. Browse REXQU’s full ECG smartwatch collection to compare models by display size, extra sensors, and price.
This article is informational and reflects product specifications published by REXQU; it is not medical advice. REXQU smartwatches are wellness devices, not diagnostic medical devices — always consult a qualified healthcare provider about heart rhythm concerns or symptoms.