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4-variable anterior STE (Driver 2017)

4-variable anterior STE

Compute the Driver 2017 4-variable formula that differentiates normal-variant ST elevation in V2-V4 (early repolarization) from subtle left anterior descending coronary occlusion, using computerized Bazett QTc, total QRS amplitude in V2, R-wave amplitude in V4, and ST elevation at 60 ms after the J-point in V3.

LIVE $0.005 USDC GET /api/calc/subtle_stemi

Markdown: /docs/subtle-stemi.md · Canonical: https://magentlab.com/docs/subtle-stemi

Not a medical device. Not a diagnosis, dose, or listing recommendation.

What it computes

Compute the Driver 2017 4-variable formula that differentiates normal-variant ST elevation in V2-V4 (early repolarization) from subtle left anterior descending coronary occlusion, using computerized Bazett QTc, total QRS amplitude in V2, R-wave amplitude in V4, and ST elevation at 60 ms after the J-point in V3.

When to use

When an agent has caller-measured millimetre amplitudes and a computerized Bazett QTc, the tracing has ≥1 mm ST elevation in V2-V4, and the differential is subtle LAD occlusion versus early repolarization. Do not use when obvious occlusion features are present.

When not to use

• Not a medical device. Not a STEMI diagnosis and not a catheterization-lab order.
• Intended only when there is ≥1 mm ST elevation in V2-V4 and the differential is subtle LAD occlusion versus early repolarization (normal-variant STE). Do not apply if obvious occlusion features are present: STE >5 mm, Q waves in V2-V4, terminal QRS distortion, anterior ST depression, inferior reciprocal change, or LVH.
• Inputs are caller-supplied millimetre amplitudes and a computerized Bazett QTc. magent does not read the ECG.
• Driver 2017 4-variable formula only (QTc, QRS V2, R V4, STE at 60 ms in V3). Not the 3-variable formula.
• lad_occlusion_suggested is true iff the rounded formula_value is ≥18.2, the derivation cutpoint with highest accuracy. magent does not assign other clinical bands.

Formula

formula_value = 0.052 * qtc_ms - 0.151 * qrs_v2_mm - 0.268 * r_v4_mm + 1.062 * ste60_v3_mm

Citation

Title

A new 4-variable formula to differentiate normal variant ST segment elevation in V2-V4 (early repolarization) from subtle left anterior descending coronary occlusion - Adding QRS amplitude of V2 improves the model

Authors

Driver BE, Khalil A, Henry T, Kazmi F, Adil A, Smith SW

Source

J Electrocardiol. 2017;50(5):561-569

DOI

10.1016/j.jelectrocard.2017.04.005

Worked example

Also searched as

• 4-variable anterior STE
• Driver 2017
• subtle LAD occlusion
• early repolarization vs LAD occlusion
• V2-V4 ST elevation
• normal variant STE vs occlusion
• 4-variable formula Driver

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/subtle_stemi?qtc_ms=400&qrs_v2_mm=20&r_v4_mm=15&ste60_v3_mm=1

Full URL: https://api.magentlab.com/api/calc/subtle_stemi?qtc_ms=400&qrs_v2_mm=20&r_v4_mm=15&ste60_v3_mm=1

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/subtle_stemi?qtc_ms=400&qrs_v2_mm=20&r_v4_mm=15&ste60_v3_mm=1"

Parameters

Bulk (POST)

POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement.

POST /api/calc/subtle_stemi Max 25 unit_amount + extra_item_amount * (n - 1) extra $0.002 PREVIEW

• 1 to 25 items. Each item uses the same keys as the GET query parameters.
• POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows.
• The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
• HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
• Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
• x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request (fixture)

{
  "items": [
    {
      "qrs_v2_mm": "20",
      "qtc_ms": "400",
      "r_v4_mm": "15",
      "ste60_v3_mm": "1"
    },
    {
      "qrs_v2_mm": "20",
      "qtc_ms": "400",
      "r_v4_mm": "15",
      "ste60_v3_mm": "1"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/subtle_stemi",
  "items": [
    {
      "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.",
      "citation": {
        "authors": "Driver BE, Khalil A, Henry T, Kazmi F, Adil A, Smith SW",
        "doi": "10.1016/j.jelectrocard.2017.04.005",
        "id": "driver-2017",
        "pmid": "28460689",
        "source": "J Electrocardiol. 2017;50(5):561-569",
        "title": "A new 4-variable formula to differentiate normal variant ST segment elevation in V2-V4 (early repolarization) from subtle left anterior descending coronary occlusion - Adding QRS amplitude of V2 improves the model"
      },
      "formula": "subtle_stemi",
      "formula_expression": "formula_value = 0.052 * qtc_ms - 0.151 * qrs_v2_mm - 0.268 * r_v4_mm + 1.062 * ste60_v3_mm",
      "qtc_ms": 400.0,
      "formula_value": 14.822,
      "lad_occlusion_suggested": false,
      "qrs_v2_mm": 20.0,
      "r_v4_mm": 15.0,
      "ste60_v3_mm": 1.0
    },
    {
      "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.",
      "citation": {
        "authors": "Driver BE, Khalil A, Henry T, Kazmi F, Adil A, Smith SW",
        "doi": "10.1016/j.jelectrocard.2017.04.005",
        "id": "driver-2017",
        "pmid": "28460689",
        "source": "J Electrocardiol. 2017;50(5):561-569",
        "title": "A new 4-variable formula to differentiate normal variant ST segment elevation in V2-V4 (early repolarization) from subtle left anterior descending coronary occlusion - Adding QRS amplitude of V2 improves the model"
      },
      "formula": "subtle_stemi",
      "formula_expression": "formula_value = 0.052 * qtc_ms - 0.151 * qrs_v2_mm - 0.268 * r_v4_mm + 1.062 * ste60_v3_mm",
      "qtc_ms": 400.0,
      "formula_value": 14.822,
      "lad_occlusion_suggested": false,
      "qrs_v2_mm": 20.0,
      "r_v4_mm": 15.0,
      "ste60_v3_mm": 1.0
    }
  ]
}

Response

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup.

{
  "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.",
  "citation": {
    "authors": "Driver BE, Khalil A, Henry T, Kazmi F, Adil A, Smith SW",
    "doi": "10.1016/j.jelectrocard.2017.04.005",
    "id": "driver-2017",
    "pmid": "28460689",
    "source": "J Electrocardiol. 2017;50(5):561-569",
    "title": "A new 4-variable formula to differentiate normal variant ST segment elevation in V2-V4 (early repolarization) from subtle left anterior descending coronary occlusion - Adding QRS amplitude of V2 improves the model"
  },
  "formula": "subtle_stemi",
  "formula_expression": "formula_value = 0.052 * qtc_ms - 0.151 * qrs_v2_mm - 0.268 * r_v4_mm + 1.062 * ste60_v3_mm",
  "qtc_ms": 400.0,
  "formula_value": 14.822,
  "lad_occlusion_suggested": false,
  "qrs_v2_mm": 20.0,
  "r_v4_mm": 15.0,
  "ste60_v3_mm": 1.0
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

Related tools

• QTc — Compute heart-rate-corrected QT using Bazett or Fridericia. The formula argument is required.

Payment

Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /docs/mcp.

Guarantees

• HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged. HTTP 402 never includes the tool JSON.
• exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
• HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
• Execution is timeout-bounded and concurrency-capped.
• Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.