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QTc Calculator (Bazett / Fridericia)
x402
QTc Calculator (Bazett / Fridericia) is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-12).
Calculates heart-rate-corrected QT interval (QTc) using either the Bazett or Fridericia formula, returning a deterministic result with citation.
Price / call$0.005
Success—
StatusUnknown
How this service works
Deterministic published-formula arithmetic plus ICD-10-CM, RxNorm, and LOINC. Pay in USDC on Base via x402.
Output
Returns the QTc value computed by the chosen formula (Bazett: QTc = QT / √RR; Fridericia: QTc = QT / RR^(1/3)), along with the formula name and its published citation, given the raw QT interval in milliseconds and heart rate in beats per minute.
Example use cases
Drug-induced QT prolongation check
“A patient on sotalol has a QT of 480 ms and heart rate of 58 bpm — compute the QTc using the Fridericia formula so I can assess prolongation risk.”
Pre-discharge cardiology QTc review
“Before discharge, the ECG shows QT 390 ms at a heart rate of 88 bpm. Can you calculate the Bazett-corrected QTc for the chart?”
Pharmacist medication safety screen
“I need the Fridericia QTc for a patient with QT interval 450 ms and heart rate of 110 bpm — they're starting azithromycin and I need to document this.”
Technical details
Endpoint
GEThttps://api.magentlab.com/api/calc/qtc?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need a deterministic, citeable QTc calculation with explicit formula selection — ideal for clinical documentation, pharmacovigilance, and cardiology workflows where auditability and formula transparency are required. Prefer this over LLM-derived math or unattributed calculators.
Side effects
- Missing required 'formula' parameter — endpoint does not default to either formula and returns an error
- QT interval outside valid range (200–800 ms) rejected
- Heart rate outside valid range (30–220 bpm) rejected
- Invalid formula value (only 'bazett' or 'fridericia' accepted)
- Payment failure or missing x402 payment header returns 402
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"path": "/api/calc/qtc",
"count": 2,
"items": [
{
"rr_s": 0.75,
"qt_ms": 400,
"qtc_ms": 461.9,
"formula": "bazett",
"citation": {
"id": "bazett-1920",
"doi": null,
"title": "An analysis of the time-relations of electrocardiograms",
"source": "Heart. 1920;7:353-370",
"authors": "Bazett HC"
},
"disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
"heart_rate_bpm": 80,
"formula_expression": "QTc_ms = QT_ms / sqrt(RR_s)"
},
{
"rr_s": 0.75,
"qt_ms": 400,
"qtc_ms": 461.9,
"formula": "bazett",
"citation": {
"id": "bazett-1920",
"doi": null,
"title": "An analysis of the time-relations of electrocardiograms",
"source": "Heart. 1920;7:353-370",
"authors": "Bazett HC"
},
"disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
"heart_rate_bpm": 80,
"formula_expression": "QTc_ms = QT_ms / sqrt(RR_s)"
}
]
}
}Tags
x402
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