The Food and Drug Administration (FDA) has approved the Apple Watch for detecting atrial fibrillation (AFib), and it can be a helpful tool in managing the condition.

People with AFib may find the Apple Watch helpful for monitoring how frequently signs of AFib occur. The Apple Watch can also detect irregular heart rhythm in people without an AFib diagnosis.

A person wearing an Apple Watch, which can detect atrial fibrillation. -2Share on Pinterest
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The Apple Watch was the first smartwatch to be FDA approved for detecting AFib.

The Apple Watch uses a technique called photoplethysmography (PPG) to plot the time between heartbeats. Using its algorithm, it can then identify an irregular pulse and AFib.

The Apple Watch is FDA approved for detecting AFib. It may be helpful for monitoring the frequency of AFib in people with the condition.

However, while an Apple Watch and other smartwatches can detect and manage AFib, they cannot provide a diagnosis. Smartwatches can be helpful in signaling when a person should seek a diagnosis from a doctor, but people should not use them as a diagnostic tool.

A 2023 study compared the Apple Watch ECG to conventional ECG testing and found the Apple Watch to be a reliable remote monitor for detecting AFib.

There are also other smartwatches that can detect AFib, including:

  • Samsung Galaxy Watch 3
  • Withings Scanwatch
  • Fitbit Sense

There are multiple Apple Watch models. Each model may differ slightly in usage, but they all track AFib in the same way through sensors.

The following models provide AFib history and irregular rhythm notifications:

  • Apple Watch SE, but this does not have the ECG app
  • Apple Watch Series 4 and 5
  • Apple Watch Series 6 or later
  • Apple Watch Ultra

People can find information on using the Apple Watch for AFib on the product website. Apple provides the following requirements for people using AFib history with the Apple Watch:

  • Get a diagnosis of AFib from a doctor.
  • Note that it is not suitable for people under 22 years old.
  • Update the iPhone to the latest iOS and the watch to the latest version of watchOS.
  • Enable Heart Rate and Wrist Detection on the Apple Watch.
  • Wear the Apple Watch at least 5 days a week, for at least 12 hours daily for consistent estimates.

Apple provides the following instructions for using an Apple Watch for AFib:

Set up AFib history

AFib history tracks the period of time in which signs of AFib are present. To set up AFib history on the Apple Watch, a person can:

  1. open the Health app on the iPhone
  2. tap on Browse
  3. tap Heart
  4. tap AFib History
  5. tap Set Up
  6. tap Get Started
  7. enter date of birth
  8. answer Yes to receiving a diagnosis of AFib from a doctor
  9. tap Continue
  10. tap Done when finished

Record lifestyle factors

To monitor signs of AFib, the Apple Watch also takes into account lifestyle factors that may affect heart rhythm. This includes:

  • amount of time exercising
  • sleep
  • weight
  • alcohol consumption
  • mindful minutes

Wearing the watch during exercise, sleep, and mindfulness logs the data automatically. People can also enter the information manually by selecting each lifestyle factor.

How to view AFib history and predictions

AFib history collects readings that people can view in the Health app. These readings provide an estimated percentage of when AFib signs were present.

To view the readings, a person can:

  1. open the Health app on iPhone
  2. select Browse, then Heart
  3. select AFib History

A lower percentage indicates less time in AFib, while higher percentages indicate a higher frequency of AFib.

Sharing AFib history

People can share their AFib history with another person, such as a doctor. In the United States, people can share their health data with a participating healthcare professional. To do so, a person can:

  1. open Health app
  2. select the Sharing tab
  3. tap on Share with your doctor and follow the onscreen instructions

Alternatively, people can share their AFib history in a PDF file.

According to Apple, people need to know the following about using the Apple Watch for AFib:

  • Enabling low power mode turns off heart rate notifications, including for irregular rhythm, and background heart measurements, which may prevent AFib history estimates.
  • The Apple Watch may not report every occurrence of an irregular rhythm, as it only checks for AFib intermittently.
  • AFib history does not notify people when AFib is happening.
  • Once people have set up AFib history, the irregular rhythm notifications automatically turn off.
  • The Apple Watch cannot identify a stroke or heart attack.
  • People should always talk with a doctor before making any change to medications.

How do you enable irregular rhythm notifications on Apple Watch?

Irregular rhythm notifications occasionally check the heartbeat for an irregular rhythm, which may indicate AFib.

Irregular rhythm notifications are not intended for people with an AFib diagnosis and will not work if AFib history is enabled.

To enable irregular rhythm notifications, people should ensure iPhone and Apple Watch software is up to date. Then, they can open the Health app on the iPhone and tap the tab labeled Browse. From there, they can select Heart, then Irregular Rhythm Notifications. This enables the notifications.

If people receive an irregular heart rhythm alert, it means the watch detected an irregular rhythm, which may indicate AFib.

People can talk with a doctor, who can carry out a physical exam and tests to check for AFib.

Is AFib an emergency?

AFib is not an emergency, but it does require urgent medical attention. People do not require an ambulance or to go to the emergency room, but they will need to see a doctor as soon as possible.

Can an Apple Watch detect blood clots?

An Apple Watch cannot detect blood clots, nor can it detect a heart attack or stroke.

If people experience symptoms such as swelling, pain, increased skin warmth, or chest pain, it is important to seek medical help immediately.

The Apple Watch contains features that can detect irregular heart rhythms and monitor the heart for signs of AFib. However, the monitoring is not continuous, so it may miss some irregular rhythms.

Using a smartwatch to track heart rhythm may help detect AFib, or for people with a diagnosis of AFib, it can help to track the frequency and share heart data with a doctor.