Syncope

Assess airway, breathing, circulation, mental status, and injury; repeat abnormal vital signs.

Persistent hypotension, unstable rhythm, hypoxemia, or incomplete recovery: Treat the immediate abnormality and identify the cause.

Obtain cardiac monitoring / IV access when instability or cardiac syncope is suspected.

Check glucose when hypoglycemia or another cause of altered consciousness is possible.

Persistent altered consciousness or shock requires a broader evaluation than uncomplicated syncope. EUSEM 2024.

Syncope: Brief loss of consciousness from transient cerebral hypoperfusion with spontaneous recovery.

Clarify whether consciousness was actually lost, what preceded the event, what witnesses observed, and how quickly the patient recovered.

Vertigo, weakness, falls without loss of consciousness, prolonged unresponsiveness, or persistent confusion suggest another process.

Reserve psychogenic pseudosyncope for the specific functional disorder rather than using “pseudosyncope” for every mimic. ESC 2018.

Assess significant presyncope with the same attention to serious causes, especially in older patients or those with cardiac disease / risk.

Near-syncope and syncope have shown similar short-term serious outcomes in older ED patients; vague dizziness alone is not equivalent to presyncope. Bastani 2019.

Brief jerking can occur with syncope.

Rapid reorientation favors syncope; prolonged confusion or lateral tongue injury increases concern for seizure.

Jerking or urinary incontinence alone does not establish seizure. Incontinence has little discriminatory value. Brigo 2013.

Persistent neurologic abnormalities require a separate neurologic evaluation.

Repeat pulse and BP; assess perfusion and oxygenation.

Assess rhythm, murmur, and heart-failure findings.

Assess for active / occult bleeding, abdominal tenderness, or pregnancy-related concern.

Perform a focused neurologic examination.

Assess traumatic injuries separately.

Consider orthostatic measurements when safe and clinically useful.

Obtain a 12-lead ECG; compare prior tracings when available.

Assess rhythm, significant bradycardia / pauses, high-grade AV block, bifascicular or other significant conduction disease, and ventricular arrhythmias.

Assess for ischemia, QT prolongation, type 1 Brugada pattern, pre-excitation, and cardiomyopathy patterns.

Consider device interrogation when pacemaker / ICD malfunction is possible.

A normal ECG does not exclude an intermittent arrhythmia. Concerning history despite a normal tracing may still warrant monitoring or further cardiac evaluation. EUSEM 2024.

Tailor laboratory testing to the history, examination, comorbidities, and remaining differential. Additional targeted testing may be appropriate when metabolic, electrolyte, renal, toxicologic, or bleeding causes remain possible. ACC/AHA/HRS 2017.

Glucose: Hypoglycemia concern or uncertain recovery

CBC: Anemia / bleeding concern

Pregnancy Test: Pregnancy possible, particularly with abdominal pain, bleeding, or hypotension

Electrolytes / Renal Function: Medication effect, arrhythmia, dehydration, renal disease, or metabolic concern

Troponin: Cardiac injury / ischemia concern or use within an appropriate risk pathway

Stool Guaiac / Rectal Examination: Consider when GI bleeding remains in the differential and the finding would contribute to the evaluation. A negative occult-blood test does not exclude clinically important acute GI bleeding. Narula 2014.

Cardiac concern: Place on monitoring and evaluate relevant ECG / structural findings.

A short period without an arrhythmia does not exclude an intermittent event.

For patients otherwise appropriate for discharge, consider ambulatory monitoring when intermittent arrhythmia remains possible.

Match monitoring duration to event frequency and level of concern.

ASPIRED 2026: Immediate 14-day monitoring increased arrhythmia detection and treatment in unexplained syncope, although recurrent syncope at one year was not significantly reduced. ASPIRED.

Pain, fear, heat, prolonged standing, nausea, diaphoresis, pallor, or dimming vision support a reflex mechanism.

Rapid recovery and a reassuring examination / ECG strengthen the diagnosis.

A typical trigger should fit the complete event and should not override cardiac or other serious findings.

Review recurrence precautions and early prodromal symptoms; sitting or lying down can reduce injury risk. ACC/AHA/HRS 2017.

Obtain supine-to-standing BP and symptoms when safe.

Sustained fall ≥20 mm Hg systolic or ≥10 mm Hg diastolic within three minutes supports classical orthostatic hypotension. ESC 2018.

Assess whether the BP change fits the event.

Review medications, oral intake, volume losses, bleeding, and autonomic disease.

Treat identified volume depletion and investigate suspected hemorrhage.

An abnormal orthostatic measurement does not by itself establish a benign cause.

• In 1,974 older ED patients, abnormal orthostatic findings did not independently predict 30-day serious outcomes. White 2019.

Consider when the history is compatible, particularly in an older patient with episodes associated with neck pressure or head movement.

Diagnosis requires reproduction of compatible symptoms during appropriate testing; an abnormal carotid response alone is insufficient.

Consider specialist evaluation rather than routine ED carotid massage. ESC 2018.

Consider when the clinical pattern supports a functional event.

Anxiety or negative testing alone does not establish the diagnosis.

Hyperventilation provocation should not establish the cause of transient loss of consciousness. ESC — Practical Instructions.

Consider after the initial ED assessment has not identified a serious cause.

Uses history, BP, ECG findings, troponin, and ED diagnostic impression. CSRS Validation.

Use as an adjunct—not an independent disposition decision.

• Canadian validation: 3,819 patients; serious outcomes were <1% in very-low / low-risk groups. CSRS 2020.

• U.S. validation: 1,263 adults ≥40 with syncope / presyncope; performance was less reassuring than in the Canadian cohort. Suh 2026.

SFSR / CHESS, ROSE, and OESIL remain useful historically, but they are not the primary modern disposition framework.

Stable recovery and reassuring evaluation without an unresolved serious concern.

A likely reflex / orthostatic mechanism supports discharge when the remainder of the evaluation is reassuring.

A definitive cause is not required in every appropriately evaluated low-risk patient.

Address contributing medications, hydration / volume issues, recurrence precautions, and follow-up.

Consider ambulatory monitoring when intermittent arrhythmia remains possible.

Return precautions: recurrent collapse, chest pain, dyspnea, bleeding, or new neurologic symptoms.

Suspected cardiac syncope

Concerning ECG or structural heart disease

Persistent abnormal vital signs or symptoms

Significant unexplained event with unresolved short-term risk

Urgent testing / monitoring that cannot be completed safely through an outpatient pathway

Intermediate-risk patients may be appropriate for structured observation rather than prolonged hospitalization. EUSEM 2024.

Recurrent dangerous arrhythmia

Shock / persistent hemodynamic instability

Another critical illness requiring intensive support

The underlying threat—not the label of syncope—determines ICU need.