ECG interval · LIVE

Brugada 1991 wide-QRS algorithm

Brugada

Apply the Brugada 1991 four-step algorithm for regular wide-QRS tachycardia and return diagnosis vt or svt plus the step that stopped the tree.

LIVE $0.005 USDC GET /api/calc/brugada

Markdown: /docs/brugada.md · Canonical: https://magentlab.com/docs/brugada

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

What it computes

Apply the Brugada 1991 four-step algorithm for regular wide-QRS tachycardia and return diagnosis vt or svt plus the step that stopped the tree.

When to use

When an agent already has the four Brugada 1991 ECG step findings as assigned by the caller and needs the published sequential VT versus SVT result. magent does not interpret ECGs. Not Brugada syndrome and not a cardioversion order.

When not to use

• Not a medical device.
• magent does not interpret ECGs. The caller assigns each Brugada 1991 step finding as true or false.
• This tool is the Brugada 1991 algorithm for regular wide-QRS tachycardia only. Not Brugada syndrome (coved ST), not Vereckei aVR, not RWPT, and not Sgarbossa.
• Not a cardioversion order or a rhythm diagnosis beyond the published four-step tree.

Formula

VT iff no_rs_precordial or else rs_interval_gt_100 or else av_dissociation or else morphology_vt (Brugada 1991; stop at first true); else SVT

Citation

Title

A new approach to the differential diagnosis of a regular tachycardia with a wide QRS complex

Authors

Brugada P, Brugada J, Mont L, Smeets J, Andries EW

Source

Circulation. 1991;83(5):1649-1659

DOI

10.1161/01.CIR.83.5.1649

Worked example

Also searched as

• Brugada algorithm
• Brugada 1991
• wide complex tachycardia algorithm
• VT versus SVT
• regular wide QRS tachycardia
• RS interval 100 ms
• precordial RS complex
• AV dissociation VT
• Brugada criteria wide QRS

Try

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

/api/calc/brugada?no_rs_precordial=false&rs_interval_gt_100=false&av_dissociation=false&morphology_vt=false

Full URL: https://api.magentlab.com/api/calc/brugada?no_rs_precordial=false&rs_interval_gt_100=false&av_dissociation=false&morphology_vt=false

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/brugada?no_rs_precordial=false&rs_interval_gt_100=false&av_dissociation=false&morphology_vt=false"

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/brugada 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": [
    {
      "av_dissociation": "false",
      "morphology_vt": "false",
      "no_rs_precordial": "false",
      "rs_interval_gt_100": "false"
    },
    {
      "av_dissociation": "false",
      "morphology_vt": "false",
      "no_rs_precordial": "false",
      "rs_interval_gt_100": "false"
    }
  ]
}

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/brugada",
  "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": "Brugada P, Brugada J, Mont L, Smeets J, Andries EW",
        "doi": "10.1161/01.CIR.83.5.1649",
        "id": "brugada-1991",
        "pmid": "2022022",
        "source": "Circulation. 1991;83(5):1649-1659",
        "title": "A new approach to the differential diagnosis of a regular tachycardia with a wide QRS complex"
      },
      "formula": "brugada",
      "formula_expression": "VT iff no_rs_precordial or else rs_interval_gt_100 or else av_dissociation or else morphology_vt (Brugada 1991; stop at first true); else SVT",
      "criteria": [
        {
          "factor": "no_rs_precordial",
          "met": false
        },
        {
          "factor": "rs_interval_gt_100",
          "met": false
        },
        {
          "factor": "av_dissociation",
          "met": false
        },
        {
          "factor": "morphology_vt",
          "met": false
        }
      ],
      "av_dissociation": false,
      "diagnosis": "svt",
      "morphology_vt": false,
      "no_rs_precordial": false,
      "rs_interval_gt_100": false,
      "stopped_at": "none"
    },
    {
      "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": "Brugada P, Brugada J, Mont L, Smeets J, Andries EW",
        "doi": "10.1161/01.CIR.83.5.1649",
        "id": "brugada-1991",
        "pmid": "2022022",
        "source": "Circulation. 1991;83(5):1649-1659",
        "title": "A new approach to the differential diagnosis of a regular tachycardia with a wide QRS complex"
      },
      "formula": "brugada",
      "formula_expression": "VT iff no_rs_precordial or else rs_interval_gt_100 or else av_dissociation or else morphology_vt (Brugada 1991; stop at first true); else SVT",
      "criteria": [
        {
          "factor": "no_rs_precordial",
          "met": false
        },
        {
          "factor": "rs_interval_gt_100",
          "met": false
        },
        {
          "factor": "av_dissociation",
          "met": false
        },
        {
          "factor": "morphology_vt",
          "met": false
        }
      ],
      "av_dissociation": false,
      "diagnosis": "svt",
      "morphology_vt": false,
      "no_rs_precordial": false,
      "rs_interval_gt_100": false,
      "stopped_at": "none"
    }
  ]
}

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": "Brugada P, Brugada J, Mont L, Smeets J, Andries EW",
    "doi": "10.1161/01.CIR.83.5.1649",
    "id": "brugada-1991",
    "pmid": "2022022",
    "source": "Circulation. 1991;83(5):1649-1659",
    "title": "A new approach to the differential diagnosis of a regular tachycardia with a wide QRS complex"
  },
  "formula": "brugada",
  "formula_expression": "VT iff no_rs_precordial or else rs_interval_gt_100 or else av_dissociation or else morphology_vt (Brugada 1991; stop at first true); else SVT",
  "criteria": [
    {
      "factor": "no_rs_precordial",
      "met": false
    },
    {
      "factor": "rs_interval_gt_100",
      "met": false
    },
    {
      "factor": "av_dissociation",
      "met": false
    },
    {
      "factor": "morphology_vt",
      "met": false
    }
  ],
  "av_dissociation": false,
  "diagnosis": "svt",
  "morphology_vt": false,
  "no_rs_precordial": false,
  "rs_interval_gt_100": false,
  "stopped_at": "none"
}

Client errors (HTTP 400)

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

Related tools

• Sgarbossa — Sum the three Sgarbossa 1996 GUSTO-1 ECG criteria in left bundle-branch block and return whether the total is ≥3.
• 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.