watchOS 5.1.2 for Apple Watch is now available. For Apple Watch Series 4 customers, the update unlocks the promised ECG app that captures a live electrocardiogram using the Apple Watch heart rate sensor and Digital Crown. The new watchOS update also includes new Apple app complication options on the new Infograph and Infograph Modular watch faces and more.

Here’s how Apple describes its new ECG app function:

Electrodes built into the Digital Crown and the back crystal work together with the ECG app to read your heart’s electrical signals. Simply touch the Digital Crown to generate an ECG waveform in just 30 seconds. The ECG app can indicate whether your heart rhythm shows signs of atrial fibrillation — a serious form of irregular heart rhythm — or sinus rhythm, which means your heart is beating in a normal pattern.

Each beat of the heart sends out an electrical impulse. With the ECG app, Apple Watch Series 4 can read and record these impulses by connecting the circuit between your heart and both arms. The resulting ECG waveform, its classification, and any notes you’ve entered on related symptoms are automatically stored in the Health app on your iPhone. You can share them with your doctor and have a better-informed conversation about your health.

All Apple Watch users running the latest watchOS 5 version will notice a new toggle for the Walkie-Talkie app in Control Center, and the Watch app icon for iOS has been changed in iOS 12.1.1 to match the new Apple Watch Series 4.

New Infograph complications discovered in beta include Find My Friends, Home, Mail, Maps, Messages, News, Phone, and Remote (but not Podcasts yet!). Apple Watch Activity challenges also now include alerts for days when 600 points (the highest amount) are earned for a day.

The latest watchOS update also enhances how tickets and reward cards work with the Wallet app, and Apple Watch Series 1 and later now support irregular heart rate rhythm alerts in the United States.

watchOS 5.1.2 release notes:

This update includes new features, improvements and bug fixes:

New ECG app on Apple Watch Series 4 (US and US territories only)

Allows you to take an electrocardiogram similar to a single-lead electrocardiogram

Can indicate whether your heart rhythm shows signs of atrial fibrillation—a serious form of irregular heart rhythm—or sinus rhythm, which means your heart is beating in a normal pattern

Saves ECG waveform, classification and any noted symptoms in a PDF on the Health app on iPhone to share with your doctor

Adds the ability to receive an alert if an irregular heart rhythm that appears to be atrial fibrillation is detected (US and US territories only)

Enables direct access to supported movie tickets, coupons, and rewards cards in Wallet when tapped to a contactless reader

Receive notifications and animated celebrations when you achieve daily maximum points in a day during an Activity competition

New Infograph complications for Mail, Maps, Messages, Find My Friends, Home, News, Phone, Remote

Manage your availability for Walkie-Talkie from Control Center

Stay tuned for more coverage of the new ECG app on Apple Watch Series 4.

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About the Author

Zac Hall

Zac covers Apple news, hosts the 9to5Mac Happy Hour podcast, and created