NYHA functional classification (1994)

NYHA

Return the 1994 NYHA functional capacity class 1-4 from a caller-assigned integer, with the published class description.

LIVE $0.005 USDC GET /api/calc/nyha

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

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

What it computes

Return the 1994 NYHA functional capacity class 1-4 from a caller-assigned integer, with the published class description.

When to use

When an agent already has a NYHA functional class 1-4 as in the 1994 9th edition and must not invent Objective Assessment A-D or ACC/AHA stages.

When not to use

Not a medical device and not a heart-failure diagnosis. magent does not examine the patient.
The caller assigns NYHA class 1-4. magent does not interview or examine the patient.
Functional capacity I-IV only (1994 9th edition). It does not implement Objective Assessment A-D or ACC/AHA stages.

Formula

NYHA functional capacity class 1-4 as assigned by the caller (Criteria Committee of the New York Heart Association 1994 9th edition); not Objective Assessment A-D

Citation

Title: Nomenclature and Criteria for Diagnosis of Diseases of the Heart and Great Vessels
Authors: The Criteria Committee of the New York Heart Association
Source: 9th ed. Boston: Little, Brown & Co; 1994. p. 253-256
DOI: none

Worked example

Class 1 no limitation

Given: nyha_class=1

nyha_class 1 → no limitation of ordinary activity; score 1; max 4

Also searched as

NYHA class
NYHA classification
NYHA functional classification
New York Heart Association class
heart failure functional class
NYHA 1994
NYHA I II III IV
functional capacity NYHA

Try

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

/api/calc/nyha?nyha_class=1

Full URL: https://api.magentlab.com/api/calc/nyha?nyha_class=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/nyha?nyha_class=1"

Parameters

Name	Type	Required	Description
`nyha_class`	integer	required	NYHA 1994 functional capacity class 1-4 as assigned by the caller (1 no limitation of ordinary activity; 2 slight limitation, comfortable at rest, ordinary activity causes symptoms; 3 marked limitation, less than ordinary activity causes symptoms; 4 inability to carry on any physical activity without discomfort, symptoms may be present at rest). magent does not examine the patient.

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/nyha 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": [
    {
      "nyha_class": "1"
    },
    {
      "nyha_class": "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/nyha",
  "items": [
    {
      "description": "Patients with cardiac disease but without resulting limitation of physical activity. Ordinary physical activity does not cause undue fatigue, palpitation, dyspnea, or anginal pain.",
      "components": [
        {
          "factor": "nyha_class",
          "points": 1,
          "present": true
        }
      ],
      "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": "The Criteria Committee of the New York Heart Association",
        "id": "nyha-1994",
        "source": "9th ed. Boston: Little, Brown & Co; 1994. p. 253-256",
        "title": "Nomenclature and Criteria for Diagnosis of Diseases of the Heart and Great Vessels"
      },
      "formula": "nyha",
      "formula_expression": "NYHA functional capacity class 1-4 as assigned by the caller (Criteria Committee of the New York Heart Association 1994 9th edition); not Objective Assessment A-D",
      "max_score": 4,
      "score": 1,
      "nyha_class": 1
    },
    {
      "description": "Patients with cardiac disease but without resulting limitation of physical activity. Ordinary physical activity does not cause undue fatigue, palpitation, dyspnea, or anginal pain.",
      "components": [
        {
          "factor": "nyha_class",
          "points": 1,
          "present": true
        }
      ],
      "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": "The Criteria Committee of the New York Heart Association",
        "id": "nyha-1994",
        "source": "9th ed. Boston: Little, Brown & Co; 1994. p. 253-256",
        "title": "Nomenclature and Criteria for Diagnosis of Diseases of the Heart and Great Vessels"
      },
      "formula": "nyha",
      "formula_expression": "NYHA functional capacity class 1-4 as assigned by the caller (Criteria Committee of the New York Heart Association 1994 9th edition); not Objective Assessment A-D",
      "max_score": 4,
      "score": 1,
      "nyha_class": 1
    }
  ]
}

Response

Field	Type	Description
`formula`	string	nyha
`formula_expression`	string	Published class rule
`nyha_class`	integer	Caller-assigned class 1-4
`score`	integer	Same as nyha_class
`max_score`	integer	4
`description`	string	1994 functional-capacity wording for that class
`components`	array	NYHA-class component
`citation`	object	NYHA 1994 9th edition
`disclaimer`	string	Not a medical device

Example JSON

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

{
  "description": "Patients with cardiac disease but without resulting limitation of physical activity. Ordinary physical activity does not cause undue fatigue, palpitation, dyspnea, or anginal pain.",
  "components": [
    {
      "factor": "nyha_class",
      "points": 1,
      "present": true
    }
  ],
  "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": "The Criteria Committee of the New York Heart Association",
    "id": "nyha-1994",
    "source": "9th ed. Boston: Little, Brown & Co; 1994. p. 253-256",
    "title": "Nomenclature and Criteria for Diagnosis of Diseases of the Heart and Great Vessels"
  },
  "formula": "nyha",
  "formula_expression": "NYHA functional capacity class 1-4 as assigned by the caller (Criteria Committee of the New York Heart Association 1994 9th edition); not Objective Assessment A-D",
  "max_score": 4,
  "score": 1,
  "nyha_class": 1
}

Client errors (HTTP 400)

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

HTTP	Code	When
400	`invalid_nyha`	nyha_class must be an integer 1, 2, 3, or 4 (NYHA 1994). Returned before settlement; you are not charged.
400	`invalid_items`	POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
400	`invalid_item_count`	items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
400	`invalid_item`	each items entry must be a JSON object Returned before settlement; you are not charged.

Related tools

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H2FPEF — Sum the Reddy 2018 H2FPEF points score (six components, max 9) and return score and max_score only.

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.