atrialFibrillationBurden: HealthKit quantity type
HKQuantityTypeIdentifierAtrialFibrillationBurden · read from Apple’s documentation on 2026-10-02
HKQuantityTypeIdentifier.atrialFibrillationBurden (Objective-C HKQuantityTypeIdentifierAtrialFibrillationBurden) is a HealthKit quantity type in Apple's "Vital signs" group. Apple's abstract: “A quantity type that measures an estimate of the percentage of time a person’s heart shows signs of atrial fibrillation (AFib) while wearing Apple Watch.” Apple's discussion says its samples use percentage units and measure discrete values, so in HKStatisticsQuery it takes .discreteAverage, .discreteMin or .discreteMax. Apple states that apps cannot save it: “These samples are read-only.” It is available from iOS 16.0 and watchOS 9.0.
What Apple says atrialFibrillationBurden is
A quantity type that measures an estimate of the percentage of time a person’s heart shows signs of atrial fibrillation (AFib) while wearing Apple Watch.
Apple’s abstract, quoted from its atrialFibrillationBurden reference page, read 2026-10-02. Apple’s discussion of the type runs 118 words.
- Swift
HKQuantityTypeIdentifier.atrialFibrillationBurden- Objective-C
HKQuantityTypeIdentifierAtrialFibrillationBurden- Family
HKQuantityTypeIdentifier- Apple's topic group
- Vital signs
- Group page
- Vital signs
- Apple's reference
- atrialFibrillationBurden on developer.apple.com
Availability
The versions Apple’s documentation data gives for atrialFibrillationBurden, platform by platform, as read on 2026-10-02.
| Platform | Introduced | Deprecated |
|---|---|---|
| iOS | 16.0 | — |
| iPadOS | 16.0 | — |
| Mac Catalyst | 16.0 | — |
| macOS | 13.0 | — |
| visionOS | 1.0 | — |
| watchOS | 9.0 | — |
The rest of that release: HealthKit Types Introduced in iOS 16.
Sum or average, and in which units
Apple states both of these in the prose of the type’s discussion, not as properties, so they are derived from Apple’s sentence and the sentence is shown with each.
Aggregation style
discrete — in an HKStatisticsQuery, use .discreteAverage, .discreteMin or .discreteMax. Apple’s sentence:
These samples use percentage units (described in ) and measure discrete values (described in ).
Unit family
percentage — every type in this family is on the HKUnit reference.
Apple states it in the same sentence as the aggregation style, quoted above.
Empty parentheses and a dangling “described in” mark links in Apple’s sentence to other documentation pages: the generator keeps the sentence’s text, not its links, and the quote is left as stored rather than repaired.
Can apps write atrialFibrillationBurden?
No. Apple’s documentation states that these samples are read-only:
These samples are read-only.
On Android Health Connect
No verified Health Connect counterpart. The cross-platform matrix pairs only metrics checked against both Apple’s and Google’s documentation, and atrialFibrillationBurden is not among them. A similarly named Health Connect record may exist, but a name match is not a verified mapping.
Questions
- Should I sum or average atrialFibrillationBurden in HealthKit?
- Average it, or take its minimum or maximum — do not sum it. Apple's documentation for atrialFibrillationBurden describes it as measuring discrete values, so an HKStatisticsQuery over it takes .discreteAverage, .discreteMin or .discreteMax. Apple's sentence, as read on 2026-10-02: "These samples use percentage units (described in ) and measure discrete values (described in )."
- Which unit family does Apple give atrialFibrillationBurden?
- Percentage. Apple's discussion of atrialFibrillationBurden says its samples use percentage units: "These samples use percentage units (described in ) and measure discrete values (described in )."
- Can my app write atrialFibrillationBurden samples to HealthKit?
- No. Apple's documentation for atrialFibrillationBurden states: "These samples are read-only." (read 2026-10-02).
- Which iOS version added atrialFibrillationBurden?
- iOS 16.0. Apple's availability data for atrialFibrillationBurden lists iOS 16.0, iPadOS 16.0, Mac Catalyst 16.0, macOS 13.0, visionOS 1.0 and watchOS 9.0.
Sources checked
- Apple — HKQuantityTypeIdentifier.atrialFibrillationBurden · read 2026-10-02
- Apple — HKQuantityTypeIdentifier · read 2026-10-02
Apple’s abstract and sentences are quoted for identification; the page layout, the capsule and the cross-platform pairing are AIFitnessAPI’s. Generated from Apple’s documentation by scripts/fetch-healthkit-identifiers.mjs, not typed by hand — the same data as the full identifier table.