What an ECG Smartwatch Actually Does
ECG is one of the most misunderstood smartwatch features. Here is what the sensor measures and what it does not.
ECG is electrical, not optical
An ECG-capable watch uses electrodes to record electrical activity associated with the heartbeat. That is fundamentally different from optical heart-rate sensing, which estimates pulse using light.
It can provide a useful snapshot
A compatible ECG feature can help identify certain rhythm patterns and produce a recording that may be useful to discuss with a qualified clinician. It is not the same as continuous clinical monitoring.
Availability depends on more than hardware
A watch may contain the required electrodes while the feature remains limited by region, regulatory authorization, software version or phone compatibility.
Treat it as a screening tool
Smartwatch health features can be useful for awareness and screening, but they should not be treated as a diagnosis or a replacement for professional medical evaluation.