Hemodynamics · LIVE

Pulmonary artery pulsatility index

PAPi

Compute Korabathina 2012 pulmonary artery pulsatility index from PA systolic, PA diastolic, and right atrial pressure.

LIVE $0.005 USDC GET /api/calc/papi

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

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

What it computes

Compute Korabathina 2012 pulmonary artery pulsatility index from PA systolic, PA diastolic, and right atrial pressure.

When to use

When an agent needs the published Korabathina 2012 PAPi ((PA systolic − PA diastolic) / RAP) and must not invent an RAP=0 substitution, a device threshold, or a diagnosis of RV failure.

When not to use

• Not a medical device. Not a diagnosis of right ventricular failure.
• 0.9 is the Korabathina 2012 ROC cut-point for in-hospital death or need for percutaneous RV support in inferior MI with suspected RVD, not a device threshold and not an RVAD/Impella indication.
• RAP 0 is invalid. Korabathina 2012 did not substitute RAP=1.
• Inputs are invasive catheter numbers. magent does not read waveforms.

Formula

papi = (pa_systolic_mm_hg - pa_diastolic_mm_hg) / ra_mm_hg

Citation

Title

The pulmonary artery pulsatility index identifies severe right ventricular dysfunction in acute inferior myocardial infarction.

Authors

Korabathina R, Heffernan KS, Paruchuri V, et al.

Source

Catheter Cardiovasc Interv. 2012;80(4):593-600

DOI

10.1002/ccd.23309

Worked example

Also searched as

• pulmonary artery pulsatility index
• PAPi
• PAPI
• PA pulsatility index
• Korabathina PAPi
• right ventricular pulsatility
• PA pulse pressure RAP

Try

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

/api/calc/papi?pa_systolic_mm_hg=30&pa_diastolic_mm_hg=12&ra_mm_hg=6

Full URL: https://api.magentlab.com/api/calc/papi?pa_systolic_mm_hg=30&pa_diastolic_mm_hg=12&ra_mm_hg=6

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/papi?pa_systolic_mm_hg=30&pa_diastolic_mm_hg=12&ra_mm_hg=6"

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/papi 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": [
    {
      "pa_diastolic_mm_hg": "12",
      "pa_systolic_mm_hg": "30",
      "ra_mm_hg": "6"
    },
    {
      "pa_diastolic_mm_hg": "12",
      "pa_systolic_mm_hg": "30",
      "ra_mm_hg": "6"
    }
  ]
}

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/papi",
  "items": [
    {
      "band": ">0.9",
      "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": "Korabathina R, Heffernan KS, Paruchuri V, et al.",
        "doi": "10.1002/ccd.23309",
        "id": "korabathina-2012",
        "pmid": "21954053",
        "source": "Catheter Cardiovasc Interv. 2012;80(4):593-600",
        "title": "The pulmonary artery pulsatility index identifies severe right ventricular dysfunction in acute inferior myocardial infarction."
      },
      "formula": "papi",
      "formula_expression": "papi = (pa_systolic_mm_hg - pa_diastolic_mm_hg) / ra_mm_hg",
      "pa_diastolic_mm_hg": 12.0,
      "pa_systolic_mm_hg": 30.0,
      "papi": 3.0,
      "ra_mm_hg": 6.0
    },
    {
      "band": ">0.9",
      "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": "Korabathina R, Heffernan KS, Paruchuri V, et al.",
        "doi": "10.1002/ccd.23309",
        "id": "korabathina-2012",
        "pmid": "21954053",
        "source": "Catheter Cardiovasc Interv. 2012;80(4):593-600",
        "title": "The pulmonary artery pulsatility index identifies severe right ventricular dysfunction in acute inferior myocardial infarction."
      },
      "formula": "papi",
      "formula_expression": "papi = (pa_systolic_mm_hg - pa_diastolic_mm_hg) / ra_mm_hg",
      "pa_diastolic_mm_hg": 12.0,
      "pa_systolic_mm_hg": 30.0,
      "papi": 3.0,
      "ra_mm_hg": 6.0
    }
  ]
}

Response

Example JSON

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

{
  "band": ">0.9",
  "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": "Korabathina R, Heffernan KS, Paruchuri V, et al.",
    "doi": "10.1002/ccd.23309",
    "id": "korabathina-2012",
    "pmid": "21954053",
    "source": "Catheter Cardiovasc Interv. 2012;80(4):593-600",
    "title": "The pulmonary artery pulsatility index identifies severe right ventricular dysfunction in acute inferior myocardial infarction."
  },
  "formula": "papi",
  "formula_expression": "papi = (pa_systolic_mm_hg - pa_diastolic_mm_hg) / ra_mm_hg",
  "pa_diastolic_mm_hg": 12.0,
  "pa_systolic_mm_hg": 30.0,
  "papi": 3.0,
  "ra_mm_hg": 6.0
}

Client errors (HTTP 400)

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

Related tools

• CPO — Compute Fincke 2004 cardiac power output in watts from mean arterial pressure and cardiac output.
• Shock index — Compute the Allgöwer–Burri shock index as heart rate in bpm divided by cuff systolic pressure in mm Hg.

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.
• 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.