Syncope ๐ซ
Clinical guide for assessment and management of syncope in the emergency department. Red flags, risk stratification, and management algorithms based on IAEM guidelines.
๐ Definition
- Syncope = Transient loss of consciousness (T-LOC) due to cerebral hypoperfusion
- Characteristics: Rapid onset, short duration, spontaneous complete recovery
- Represents 2-3% of ED attendances
- 40% of population experience syncope during lifetime
- Differentiation between causes depends on thorough history taking
๐ Minimum Assessment (All Patients)
- Thorough history (event, collateral, background)
- Cardiorespiratory examination
- ECG evaluation
- Other examination as dictated by history
๐ History Taking
| Aspect | Key Points |
|---|---|
| Event History | Position and activity prior, situation, prodrome, eye witness account, post-event symptoms |
| Background | Previous syncopes (timing, frequency), PMHx (IHD, epilepsy, Parkinson's), medications, alcohol, social/functional history in elderly |
| Family History | Blackouts, channelopathy, sudden cardiac death |
| Systems Review | Complete systems review to identify secondary syncope |
๐ฉ History Red Flags (High Risk)
- Supine syncope
- Exertional syncope
- Sudden onset palpitations immediately preceding syncope
- Chest pain, dyspnoea, abdominal pain or headache
- New unexplained breathlessness
- Severe structural heart disease or coronary artery disease
- CCF, EF <35% (high likelihood arrhythmogenic events), previous MI
๐ History Orange Flags (Treat as Red if Associated with Structural Heart Disease or Abnormal ECG)
- Seated syncope
- Sudden drop without warning or short (<10sec) prodrome
- FHx channelopathy, Sudden adult death
โ History Green Flags (Low Risk)
- 3Ps: Provoking factor, typical prodrome, and postural (from standing)
- During a meal or postprandial
- Triggered by cough, defaecation or micturition
- On head movement or pressure on carotid sinus
- On standing from seated/lying
- Long history of recurrent syncope with similar characteristics
๐ฉบ Examination
- Cardiorespiratory exam (mandatory)
- Neurological/other examination as dictated by history and systems review
๐ฉ Examination Red Flags
- Unexplained SBP <90mmHg in the ED
- Undiagnosed systolic murmur
- Evidence of GI bleed
- Persistent bradycardia <40bpm in awake state (in absence of physical training)
โ Examination Green Flag
- Normal examination
๐งช Investigations
| Investigation | When to Perform |
|---|---|
| ECG | Always (mandatory) |
| Lying-Standing BP | If syncope related to standing or postural symptoms |
| ฮฒHCG | If patient is female of child-bearing age |
| Bedside BSL | If indicated |
| Device Interrogation | If patient has cardiac device (PPM/ICD) |
| Other Tests | If investigating secondary syncope |
โ ๏ธ Low Yield Investigations (Avoid Routine Use)
- Chest X-ray
- CT brain
- Routine blood haematology/biochemistry
- D-dimer levels
- Cardiac markers
- Note: Only use if specifically suggested by clinical evaluation
๐ฉ ECG Red Flags
- Changes consistent with acute ischaemia
- AV block: Mobitz II or third-degree
- AFib <40bpm
- Persistent sinus brady <40bpm, sinus pauses >3 sec
- Bundle branch block, Bi-, Tri-fascicular block
- Sustained and non-sustained VT
- Prolonged QTc (>460ms), Type 1 Brugada pattern, HOCM criteria
- Dysfunction of an ICD or PPM
๐ ECG Orange Flags (Treat as Red if History Suggests Arrhythmic Syncope)
- AV Block: Marked first-degree or Mobitz I
- Mild bradycardia: AFib/sinus <50
- Paroxysmal SVT or AFib
- ARVC, atypical Brugada patterns, short QTc (<340ms), WPW
โ ECG Green Flag
- Normal ECG
๐ฉ Other Investigations Red Flags (if indicated)
- Anaemia, HCT <30%
- Electrolyte disturbance
๐ก Special Note: Falls in Older Patients
- CAUTION: Attributing injuries in older patients to falls and failing to recognise amnesia associated with syncope is common
- Good practice: Perform baseline ECG on all patients presenting with falls aged โฅ65 years
- This patient group should at minimum have a syncopal diagnosis considered
๐ Syncope Classification
| Type | Features | Management |
|---|---|---|
| Vasovagal | 3Ps: Provocation, Prodrome, Postural. Unpleasant sensation: sight, smell, touch, pain, emotional distress, fear | Reassurance and education, trigger avoidance, symptom recognition. Usually home with simple advice. +/- GP follow up. If severe (high risk/frequency), may require specialist input |
| Situational | Cough, GI stimulation, micturition. Post-prandial, post-exertional | Reassurance and education, trigger avoidance. Usually home with simple advice |
| Carotid Sinus Hypersensitivity | Head turning, tight collars | Reassurance and education, trigger avoidance. May require specialist input if reflex asystole (may benefit from PPM) |
| Orthostatic (Primary Autonomic Failure) | Occurs on standing. Neurological causes | Admit if ongoing symptomatic. If safe for discharge: increase fluid, salt intake, PCM. May require specialist input for medication rationalisation, autonomic function testing |
| Orthostatic (Secondary Autonomic Failure) | Occurs on standing. Diabetes, amyloid, alcohol, drug-induced (anti-HTN meds, anti-depressants, glaucoma drops) | Admit if ongoing symptomatic. If safe for discharge: increase fluid, salt intake, PCM. May require specialist input for medication rationalisation |
| Volume Depletion | Occurs on standing. Diarrhoea, GI bleed, leaking AAA | If correctable self-limiting condition (acute dehydration) can discharge home with advice and GP follow up. Consider secondary syncope |
| Cardiogenic (Bradycardia) | Sinus node disease, AV block, Bi/Trifascicular block, Pacemaker malfunction | Telemetry mandatory if recurrent/unstable arrhythmia. Admit if indication for PPM/ICD/ablation. Arrange prompt device interrogation if PPM/ICD |
| Cardiogenic (Tachycardia) | SVT, VT, WPW, Brugada, ARVC, Prolonged QT | Telemetry mandatory if recurrent/unstable arrhythmia. Admit if indication for ablation/ICD. Arrange prompt device interrogation if ICD |
| Cardiogenic (Structural) | Ischaemic CM, HOCM, Congenital, Aortic stenosis | Admit for treatment of underlying condition. May require valve repair etc |
๐ฏ Management Approach
| Risk Category | Features | Management |
|---|---|---|
| High Risk (Red Flags) | Red flags present (see above) | Intensive diagnostic approach, urgent treatment, admission required |
| Moderate Risk | Neither high-risk nor low-risk features | ESC guidance: require expert syncopal opinion. May require admission or specialist referral |
| Low Risk (Green Flags) | Green flags present (see above) | No further diagnostic tests in ED. Likely reflex, situational, or orthostatic syncope. If currently well, can discharge without follow up. May benefit from reassurance/patient education. Can refer to outpatient syncope clinic if needed |
๐ Fitness to Drive
- Consider patient's fitness to drive if safe for discharge
๐ External Resources
Note Template
Ready-to-use clinical note structure
๐ 23 / 05 / 2026 โ 14:13 ATRP re: syncope / blackout / T-LOC Patient: [age] [sex] Admission Dx: [reason for admission] PMHx: [IHD, CCF, epilepsy, Parkinson's, structural heart disease, previous syncopes] ๐งพ Event History: โข Position/activity prior: [standing / seated / supine / exertional] โข Situation: [3Ps - Provoking factor, Prodrome, Postural] โข Prodrome: [dizziness / nausea / sweating / palpitations / none / <10sec] โข Witness account: [yes/no] - [description of event] โข Post-event: [rapid recovery / confusion / injury] ๐งพ Background: โข Previous syncopes: [frequency / timing / similar characteristics] โข Medications: [antihypertensives / diuretics / antiarrhythmics / others] โข Family Hx: [blackouts / channelopathy / sudden cardiac death] โข Social: [functional status in elderly / driving status] ๐ฉบ Exam: โข Vitals: HR __ BP __ (lying/standing) __ RR __ Temp __ SpOโ __ โข Cardiorespiratory: [normal / murmur / JVP / oedema / creps] โข Neurological: [normal / focal signs] โข Other: [as dictated by history] ๐งช Investigations: โข ECG: [normal / abnormal - specify findings] โข Lying-standing BP: [if postural symptoms] โข ฮฒ-HCG: [if female of child-bearing age] โข BSL: __ โข Other: [as indicated] ๐ฉ Risk Assessment: โข Red flags: [supine/exertional syncope / palpitations / chest pain / structural heart disease / abnormal ECG / other] โข Orange flags: [seated syncope / sudden drop / FHx channelopathy] โข Green flags: [3Ps / situational triggers / recurrent similar episodes] ๐ Impression: Likely type: [vasovagal / situational / orthostatic / cardiogenic / secondary / unclear] Risk category: [high / moderate / low] ๐ Plan: โข [If high risk: Admit for telemetry, intensive workup, urgent treatment] โข [If moderate risk: Consider admission or Syncope Unit referral] โข [If low risk: Reassurance, education, trigger avoidance. Discharge if well] โข [Device interrogation if PPM/ICD] โข [Fitness to drive assessment if discharging] โข [Follow-up: GP / Syncope Unit / Cardiology / other] ๐ค [Your Name], [Role] IMC: _______