Google Health API reference

Electrocardiogram (ECG): the Google Health API electrocardiogram data type

Read from Google’s documentation on 2026-10-17 · discovery document revision 20261014 · Google’s data-types page last updated 2026-10-06

Electrocardiogram (ECG) (electrocardiogram) is a Session data type in the Google Health API. Google's data-types table lists list for it under the .ecg.readonly scope. The table marks it with neither webhook nor true-zeros support. Google's Fitbit migration table maps the Fitbit Web API's Electrocardiogram (ECG) data to it.

Electrocardiogram (ECG) at a glance

From the Electrocardiogram (ECG) row of Google’s data-types table, joined to the discovery document’s DataPoint schema.

Display name: Electrocardiogram (ECG)
dataType (in endpoint URLs): electrocardiogram
filter parameter: electrocardiogramGoogle: “The identifier separated by underscores (for example, active_minutes) used as the value for the dataType filter parameter in daily rollup and rollup requests.”
Record type: Session — Google: “Represents a continuous block of recording, such as a workout or an electrocardiogram (ECG) session.”
Storage resolution: not stated in Google’s table
Webhook support: Not marked in Google’s table
True zeros support: Not marked in Google’s table
Channel: v4
DataPoint field: DataPoint.electrocardiogram → ElectrocardiogramIts description: “Optional. Data for points in the electrocardiogram session data type collection.”
Compatible devices: 8 in Google’s table

Operations and request paths

The operations Google’s table lists for electrocardiogram, each matched to its users.dataTypes.dataPoints method in the discovery document. The path is the documented path template (the method’s flatPath on https://health.googleapis.com/) with {dataTypesId} filled in as electrocardiogram. Google on {user}: “The {user} can be either the alias me or the authenticated user's numeric Health User ID (retrieved via GetIdentity).”

Table lists	Method	Documented path template
`list`	`list`	`GET https://health.googleapis.com/v4/users/{usersId}/dataTypes/electrocardiogram/dataPoints`

Every method, and how many of the data types list it: the methods overview.

Scopes

The scopes Google’s table lists for electrocardiogram, as full URLs, with the consent text Google’s Scopes page gives each. Every Google Health API scope.

Scope	Access	Google’s permission text
`https://www.googleapis.com/auth/googlehealth.ecg.readonly`	read	See your Google Health ECG data.

Fields of Electrocardiogram (ECG)

The schema the discovery document gives DataPoint.electrocardiogram, required fields first. Types are as the discovery document states them; the label is the word Google’s description opens with. The schemas its fields refer to follow, one level deep.

Electrocardiogram — Google: “Represents an Electrocardiogram (ECG) measurement session. This data type is based on SaMD feature and any changes to it may require additional review.”

Field	Type	Google’s description
`interval`Required	`SessionTimeInterval`	Required. Observed interval. NOTE: Historical ECG data lacks timezone offsets, so `start_utc_offset` and `end_utc_offset` will be missing or default to zero. As a result, the civil time fields within this interval will default to UTC. It is recommended to use physical time fields instead for accurate time referencing. NOTE: The `start_time` and `end_time` of the interval are equal, representing the reading time.
`beatsPerMinuteAvg`Optional	`string/int64`	Optional. Average heart rate recorded during ECG reading in beats per minute.
`leadNumber`Optional	`integer/int32`	Optional. The number of leads used for ECG reading.
`medicalDeviceInfo`Output only	`MedicalDeviceInfo`	Output only. The meta information for the compatible device used to conduct the measurement. ECG measurements typically populate `firmware_version`, `feature_version`, and `device_model`.
`millivoltsScalingFactor`Optional	`integer/int32`	Optional. The factor by which to divide waveform samples to get voltage in millivolts: millivolts = waveform_sample / millivolts_scaling_factor.
`resultClassification`Optional	`string`	Optional. The result classification of the ECG reading. `RESULT_CLASSIFICATION_UNSPECIFIED` — Unspecified result classification. `NORMAL_SINUS_RHYTHM` — Heart rhythm appears normal. Corresponds to result "Normal Sinus Rhythm". `ATRIAL_FIBRILLATION` — Signs of Atrial Fibrillation detected. Corresponds to result "Atrial Fibrillation". `INCONCLUSIVE` — The reading is inconclusive as it could not be classified. Corresponds to result "Inconclusive". `INCONCLUSIVE_HIGH_HEART_RATE` — The reading is inconclusive as it could not be classified because heart rate is high (>120bpm). Corresponds to result "Inconclusive: High heart rate". `INCONCLUSIVE_LOW_HEART_RATE` — The reading is inconclusive as it could not be classified because heart rate is low (<50bpm). Corresponds to result "Inconclusive: Low heart rate". `UNREADABLE` — The reading is unreadable. `NOT_ANALYZED` — The reading was not analyzed.
`samplingFrequencyHertz`Optional	`integer/int32`	Optional. The sampling frequency of waveform samples in hertz.
`waveformSamples`Optional	`array<integer/int32>`	Optional. An array of voltage values representing lead I ECG values. Each sample represents voltage difference in ECG graph. The first value in array corresponds to the start of the reading.

`SessionTimeInterval`

Google: “Represents a time interval of session data point, which bundles multiple observed metrics together.”

Field	Type	Google’s description
`endTime`Required	`string/google-datetime`	Required. The end time of the observed session.
`endUtcOffset`Required	`string/google-duration`	Required. The offset of the user's local time at the end of the session relative to the Coordinated Universal Time (UTC).
`startTime`Required	`string/google-datetime`	Required. The start time of the observed session.
`startUtcOffset`Required	`string/google-duration`	Required. The offset of the user's local time at the start of the session relative to the Coordinated Universal Time (UTC).
`civilEndTime`Output only	`CivilDateTime`	Output only. Session end time in civil time in the timezone the subject is in at the end of the session.
`civilStartTime`Output only	`CivilDateTime`	Output only. Session start time in civil time in the timezone the subject is in at the start of the session.

`MedicalDeviceInfo`

Google: “Software as Medical Device (SaMD) metadata. Used to construct the Unique Device Identifier (UDI).”

Field	Type	Google’s description
`algorithmVersion`Output only	`string`	Output only. The algorithm version used by the feature.
`deviceModel`Output only	`string`	Output only. The model name or device type of the compatible device used to collect the data.
`featureVersion`Output only	`string`	Output only. The version of the feature/app running on the device.
`firmwareVersion`Output only	`string`	Output only. The firmware version running on the compatible device used to collect the data.
`serviceVersion`Output only	`string`	Output only. The service version used by the feature.

Fitbit Web API predecessor

Google’s Fitbit Web API → Google Health API data-type table maps Electrocardiogram (ECG) to electrocardiogram.

Fitbit Web API scopes Google maps to electrocardiogram’s scopes: electrocardiogram.

Google’s full Fitbit Web API mapping tables · the migration playbook

Compatible devices

The 8 devices Google’s table lists as able to record and sync electrocardiogram.

Fitbit Charge 5
Fitbit Charge 6
Pixel Watch
Pixel Watch 2
Pixel Watch 3
Pixel Watch 4
Fitbit Sense
Fitbit Sense 2

Google’s documentation

Related on this site

ECG API: Electrocardiogram and Irregular Rhythm Data — the metric on every platform this site covers, each type quoted in its platform's own words
Verification and rate limits
The Fitbit Web API turn-off

Questions

Which OAuth scopes does the Google Health API electrocardiogram data type need?

Google's data-types table (read 2026-10-17) lists https://www.googleapis.com/auth/googlehealth.ecg.readonly for electrocardiogram. The Scopes page's consent text: .ecg.readonly, "See your Google Health ECG data."

Can apps write electrocardiogram (ECG) data to the Google Health API?

Not according to Google's data-types table, read 2026-10-17: it lists only list for electrocardiogram, and no create, update or batchDelete operation.

How do you aggregate electrocardiogram data with the Google Health API?

Not with rollUp or dailyRollUp, going by Google's data-types table: it lists only list for electrocardiogram. Read the data points with list (or reconcile, where listed) and compute any summary yourself.

What did the Google Health API electrocardiogram data type replace in the Fitbit Web API?

Google's Fitbit Web API migration table maps the Fitbit Web API's "Electrocardiogram (ECG)" to electrocardiogram. The Fitbit Web API scope Google maps to its scopes: electrocardiogram.

Sources checked

Google Health API data types — last updated 2026-10-06 · read 2026-10-17
Google Health API discovery document (v4) — revision 20261014 · read 2026-10-17
Scopes — last updated 2026-10-09 · read 2026-10-17
API specifications — last updated 2026-09-22 · read 2026-10-17

Google’s text is quoted for identification; each guide page’s footer reads: “Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 4.0 License, and code samples are licensed under the Apache 2.0 License.”. Generated from Google’s pages by scripts/fetch-google-health-api.mjs, not typed by hand; Google’s documentation remains the authority.

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