# Boston Syncope criteria

Boston Syncope

Status: LIVE
Price: $0.005 USDC
`GET /api/calc/boston_syncope`
HTML: https://magentlab.com/docs/boston-syncope
Markdown: https://magentlab.com/docs/boston-syncope.md

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

## What it computes

Apply the Grossman 2007 Boston Syncope criteria from eight caller-assigned flags and return whether any high-risk (Boston-positive) flag is present.

## When to use

When an agent already has the eight Grossman 2007 flags for an adult (paper enrolled ages 18 and older) with syncope and needs whether the published criteria are high-risk (Boston-positive) or low-risk. magent does not examine the patient, interpret an ECG, or assay hematocrit.

## When not to use

- Not a medical device.
- Not a disposition or admission order.
- magent does not examine the patient or interpret ECG or hematocrit. The caller assigns the eight flags.
- Adult tool (Grossman 2007 enrolled patients 18 years and older). Age is not a parameter.
- Not San Francisco Syncope, EGSYS, ROSE, or OESIL.

## Formula

```
high_risk iff acs_signs_symptoms or conduction_disease or worrisome_cardiac_history or valvular_heart_disease or family_history_sudden_death or persistent_abnormal_vitals or volume_depletion or primary_cns_event; low_risk iff not high_risk (Grossman 2007 Boston Syncope; Boston-positive iff any of eight caller-assigned flags)
```

## Citation

[Predicting adverse outcomes in syncope](https://doi.org/10.1016/j.jemermed.2007.04.001)
Grossman SA, Fischer C, Lipsitz LA, et al.
J Emerg Med. 2007;33(3):233-239
DOI: [10.1016/j.jemermed.2007.04.001](https://doi.org/10.1016/j.jemermed.2007.04.001)

## Worked example

### All eight flags false (low_risk)

Given: `acs_signs_symptoms=false, conduction_disease=false, family_history_sudden_death=false, persistent_abnormal_vitals=false, primary_cns_event=false, valvular_heart_disease=false, volume_depletion=false, worrisome_cardiac_history=false`

1. acs_signs_symptoms false
2. conduction_disease false
3. worrisome_cardiac_history false
4. valvular_heart_disease false
5. family_history_sudden_death false
6. persistent_abnormal_vitals false
7. volume_depletion false
8. primary_cns_event false
9. high_risk_any is false; high_risk is false; low_risk is true


### ACS signs and symptoms only (high_risk)

Given: `acs_signs_symptoms=true, conduction_disease=false, family_history_sudden_death=false, persistent_abnormal_vitals=false, primary_cns_event=false, valvular_heart_disease=false, volume_depletion=false, worrisome_cardiac_history=false`

1. acs_signs_symptoms true is a Boston-positive flag
2. The other seven flags are false
3. high_risk_any is true; high_risk is true; low_risk is false


### All eight flags true (high_risk)

Given: `acs_signs_symptoms=true, conduction_disease=true, family_history_sudden_death=true, persistent_abnormal_vitals=true, primary_cns_event=true, valvular_heart_disease=true, volume_depletion=true, worrisome_cardiac_history=true`

1. Each of the eight flags is true
2. high_risk_any is true; high_risk is true; low_risk is false


## Also searched as

- Boston Syncope Criteria
- Boston Syncope Rule
- Grossman 2007 syncope
- Boston-positive syncope
- ED syncope Boston criteria
- eight-flag syncope rule
- Grossman adverse outcomes syncope
- Boston syncope high risk

## Parameters

- `acs_signs_symptoms` (boolean, required): Signs and symptoms of acute coronary syndrome as assigned by the caller (Grossman 2007). true is a Boston-positive flag. magent does not examine the patient.
- `conduction_disease` (boolean, required): Signs of conduction disease as assigned by the caller (Grossman 2007). true is a Boston-positive flag. magent does not interpret an ECG.
- `worrisome_cardiac_history` (boolean, required): Worrisome cardiac history as assigned by the caller (Grossman 2007). true is a Boston-positive flag. magent does not take a history.
- `valvular_heart_disease` (boolean, required): Valvular heart disease by history or physical examination as assigned by the caller (Grossman 2007). true is a Boston-positive flag. magent does not examine the patient.
- `family_history_sudden_death` (boolean, required): Family history of sudden death as assigned by the caller (Grossman 2007). true is a Boston-positive flag. magent does not take a history.
- `persistent_abnormal_vitals` (boolean, required): Persistent abnormal vital signs in the ED as assigned by the caller (Grossman 2007). true is a Boston-positive flag. magent does not measure vital signs.
- `volume_depletion` (boolean, required): Volume depletion (persistent dehydration, GI bleeding, or hematocrit <30) as assigned by the caller (Grossman 2007). true is a Boston-positive flag. magent does not assay hematocrit.
- `primary_cns_event` (boolean, required): Primary central nervous system event as assigned by the caller (Grossman 2007). true is a Boston-positive flag. magent does not interpret imaging.

## 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.

Method: `POST /api/calc/boston_syncope`
Max items: 25
Price: unit_amount + extra_item_amount * (n - 1) (unit 5000 atomic, extra 2000 atomic)
Status: 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:

```json
{
  "items": [
    {
      "acs_signs_symptoms": "false",
      "conduction_disease": "false",
      "family_history_sudden_death": "false",
      "persistent_abnormal_vitals": "false",
      "primary_cns_event": "false",
      "valvular_heart_disease": "false",
      "volume_depletion": "false",
      "worrisome_cardiac_history": "false"
    },
    {
      "acs_signs_symptoms": "false",
      "conduction_disease": "false",
      "family_history_sudden_death": "false",
      "persistent_abnormal_vitals": "false",
      "primary_cns_event": "false",
      "valvular_heart_disease": "false",
      "volume_depletion": "false",
      "worrisome_cardiac_history": "false"
    }
  ]
}
```

Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/boston-syncope

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/boston_syncope",
  "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": "Grossman SA, Fischer C, Lipsitz LA, et al.",
        "doi": "10.1016/j.jemermed.2007.04.001",
        "id": "grossman-2007",
        "pmid": "17976548",
        "source": "J Emerg Med. 2007;33(3):233-239",
        "title": "Predicting adverse outcomes in syncope"
      },
      "formula": "boston_syncope",
      "formula_expression": "high_risk iff acs_signs_symptoms or conduction_disease or worrisome_cardiac_history or valvular_heart_disease or family_history_sudden_death or persistent_abnormal_vitals or volume_depletion or primary_cns_event; low_risk iff not high_risk (Grossman 2007 Boston Syncope; Boston-positive iff any of eight caller-assigned flags)",
      "criteria": [
        {
          "factor": "acs_signs_symptoms",
          "met": false
        },
        {
          "factor": "conduction_disease",
          "met": false
        },
        {
          "factor": "worrisome_cardiac_history",
          "met": false
        },
        {
          "factor": "valvular_heart_disease",
          "met": false
        },
        {
          "factor": "family_history_sudden_death",
          "met": false
        },
        {
          "factor": "persistent_abnormal_vitals",
          "met": false
        },
        {
          "factor": "volume_depletion",
          "met": false
        },
        {
          "factor": "primary_cns_event",
          "met": false
        },
        {
          "factor": "high_risk_any",
          "met": false
        }
      ],
      "high_risk": false,
      "low_risk": 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": "Grossman SA, Fischer C, Lipsitz LA, et al.",
        "doi": "10.1016/j.jemermed.2007.04.001",
        "id": "grossman-2007",
        "pmid": "17976548",
        "source": "J Emerg Med. 2007;33(3):233-239",
        "title": "Predicting adverse outcomes in syncope"
      },
      "formula": "boston_syncope",
      "formula_expression": "high_risk iff acs_signs_symptoms or conduction_disease or worrisome_cardiac_history or valvular_heart_disease or family_history_sudden_death or persistent_abnormal_vitals or volume_depletion or primary_cns_event; low_risk iff not high_risk (Grossman 2007 Boston Syncope; Boston-positive iff any of eight caller-assigned flags)",
      "criteria": [
        {
          "factor": "acs_signs_symptoms",
          "met": false
        },
        {
          "factor": "conduction_disease",
          "met": false
        },
        {
          "factor": "worrisome_cardiac_history",
          "met": false
        },
        {
          "factor": "valvular_heart_disease",
          "met": false
        },
        {
          "factor": "family_history_sudden_death",
          "met": false
        },
        {
          "factor": "persistent_abnormal_vitals",
          "met": false
        },
        {
          "factor": "volume_depletion",
          "met": false
        },
        {
          "factor": "primary_cns_event",
          "met": false
        },
        {
          "factor": "high_risk_any",
          "met": false
        }
      ],
      "high_risk": false,
      "low_risk": true
    }
  ]
}
```

## Response fields

- `formula` (string): boston_syncope
- `formula_expression` (string): Grossman 2007 Boston Syncope: high_risk if any of the eight caller-assigned flags
- `high_risk` (boolean): true iff any of the eight flags is true (Boston-positive). Not a disposition or admission order.
- `low_risk` (boolean): true iff none of the eight flags is true (not high_risk)
- `criteria` (array): Per-flag rows plus high_risk_any (met iff any of the eight flags is true)
- `citation` (object): Grossman 2007 J Emerg Med citation
- `disclaimer` (string): Not-a-device notice

## Example JSON

Frozen fixture. Not a live lookup.

```json
{
  "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": "Grossman SA, Fischer C, Lipsitz LA, et al.",
    "doi": "10.1016/j.jemermed.2007.04.001",
    "id": "grossman-2007",
    "pmid": "17976548",
    "source": "J Emerg Med. 2007;33(3):233-239",
    "title": "Predicting adverse outcomes in syncope"
  },
  "formula": "boston_syncope",
  "formula_expression": "high_risk iff acs_signs_symptoms or conduction_disease or worrisome_cardiac_history or valvular_heart_disease or family_history_sudden_death or persistent_abnormal_vitals or volume_depletion or primary_cns_event; low_risk iff not high_risk (Grossman 2007 Boston Syncope; Boston-positive iff any of eight caller-assigned flags)",
  "criteria": [
    {
      "factor": "acs_signs_symptoms",
      "met": false
    },
    {
      "factor": "conduction_disease",
      "met": false
    },
    {
      "factor": "worrisome_cardiac_history",
      "met": false
    },
    {
      "factor": "valvular_heart_disease",
      "met": false
    },
    {
      "factor": "family_history_sudden_death",
      "met": false
    },
    {
      "factor": "persistent_abnormal_vitals",
      "met": false
    },
    {
      "factor": "volume_depletion",
      "met": false
    },
    {
      "factor": "primary_cns_event",
      "met": false
    },
    {
      "factor": "high_risk_any",
      "met": false
    }
  ],
  "high_risk": false,
  "low_risk": true
}
```

## Errors

- HTTP 400 `invalid_flag`: boolean clinical flags must be true or false Returned before settlement; you are not charged.
- HTTP 400 `invalid_items`: POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
- HTTP 400 `invalid_item_count`: items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
- HTTP 400 `invalid_item`: each items entry must be a JSON object Returned before settlement; you are not charged.

Shared HTTP 402 and 503: https://magentlab.com/docs/payments

## Related tools

- [San Francisco Syncope Rule](https://magentlab.com/docs/sf-syncope) — Compute the San Francisco Syncope Rule (CHESS) criterion count and rule-positive flag from published cutoffs.
- [EGSYS](https://magentlab.com/docs/egsys) — Sum the six Del Rosso 2008 EGSYS flags and return whether the total is ≥3 (published cardiac-syncope triage discriminator).
- [OESIL](https://magentlab.com/docs/oesil) — Compute the Osservatorio Epidemiologico sulla Sincope nel Lazio (OESIL) risk score as the Colivicchi 2003 arithmetic sum of four predictors: age >65 years, history of cardiovascular disease, syncope without prodromes, and abnormal ECG.
- [ROSE](https://magentlab.com/docs/rose) — Compute the Reed 2010 ROSE (BRACES) criterion count and high-risk flag from published cutoffs.

## 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.

- GET the tool with Accept: application/json (do not send Accept: text/html unless you want the human paywall).
- HTTP 402 means you have not paid. Decode the base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote.
- Sign accepts[0] (exact, EIP-3009) with validBefore = now + maxTimeoutSeconds (600 seconds), or accepts[1] (batch-settlement deposit/voucher) on product GET. Ping and POST {items} stay exact. Magent retries transient facilitator 429/5xx before answering.
- Retry the same URL with PAYMENT-SIGNATURE (base64 JSON of accepted and payload). Magent attaches canonical extensions.bazaar on CDP verify/settle; echoing 402 bazaar is optional.
- Success is HTTP 200 JSON plus PAYMENT-RESPONSE. exact settles before the tool. batch-settlement verifies (and deposit-settles) before the tool and commits the charge after HTTP 2xx. HTTP 503: retry the same PAYMENT-SIGNATURE. Mint a new exact nonce only after a new HTTP 402.

- offered `exact` on eip155:8453: Fixed-price USDC on Base. The buyer authorizes the advertised amount (EIP-3009). magent settles before the tool runs (paymentFlow upfront). extra.assetTransferMethod=eip3009 extra.paymentFlow=upfront.
- offered `batch-settlement` on eip155:8453: Payment-channel vouchers claimed later in batches. Exact stays accepts[0]. Same-path POST {items} is still exact. extra.assetTransferMethod=eip3009 extra.paymentFlow=authorization.

- not offered `upto`: Not offered. Usage-based: buyer authorizes a ceiling, seller settles the actual amount after work. Reserved for a future metered tool. Not for current calculators or code search.

Same-path POST {items} is still scheme exact: one EIP-3009 authorization for GET unit plus $0.002 per extra item. That is not x402 batch-settlement (payment channels / vouchers).

Shared HTTP 402 and 503 table: https://magentlab.com/docs/payments

Stdio MCP (one process per host): https://magentlab.com/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.