---
title: HKMetadataKeyAppleECGAlgorithmVersion
framework: healthkit
role: symbol
role_heading: Global Variable
path: healthkit/hkmetadatakeyappleecgalgorithmversion
---

# HKMetadataKeyAppleECGAlgorithmVersion

A key for metadata indicating the version number of the algorithm Apple Watch uses to generate an ECG reading.

## Declaration

```swift
let HKMetadataKeyAppleECGAlgorithmVersion: String
```

## Discussion

Discussion Apple Watch sets this key on the HKElectrocardiogram samples it creates. The key is read-only.

## See Also

### Specifying Metadata

- [HKAppleECGAlgorithmVersion](healthkit/hkappleecgalgorithmversion.md)