The Apple Watch Series 4 can now take an electrocardiogram (ECG) reading …

This is something that normally requires specialist medical equipment, Apple says it is the first time consumers have ever been able to buy an ECG advice without a prescription. The Apple Watch Series 4 has been approved by the FDA for this purpose.

AliveCor takes issue with the ‘first time’ claim, noting that its KardiaBand got there first, but the technology is sufficiently different that the FDA considers it a completely new type of use.

An ECG measures electrical activity of the heart over a period of time, detecting tiny electrical changes on the skin created by the heart’s electrophysiologic pattern of depolarizing and repolarizing during each heartbeat. An ECG can help detect a variety of cardiac problems.

The Watch takes the reading by asking you to hold your finger on the digital crown for 30 seconds, and creates a PDF you can share with your doctor.

Apple says that the feature will be activated later this year. It will only be available in the US, almost certainly due to regulatory requirements.