Syncope - Emergency Department Assessment

Quick Answer

One-liner: Syncope is transient loss of consciousness with loss of postural tone due to global cerebral hypoperfusion, requiring systematic risk stratification to identify life-threatening cardiac causes.

Syncope accounts for 1-3% of ED presentations and 6% of hospital admissions. While reflex syncope is most common (40-50%), cardiac syncope carries 10-30% one-year mortality. The ED physician's priority is to identify high-risk patients requiring admission and cardiac workup while safely discharging low-risk reflex syncope patients. ECG is the single most important investigation. Risk stratification tools (Canadian Syncope Score, San Francisco Syncope Rule) help guide disposition decisions.

---

ACEM Exam Focus

Primary Exam Relevance

• Anatomy: Cardiac conduction system, carotid sinus, autonomic nervous system, cerebral autoregulation
• Physiology: Cerebral blood flow regulation, cardiovascular reflexes, orthostatic haemodynamic response, neurally mediated syncope mechanisms
• Pharmacology: QT-prolonging drugs, antihypertensives causing orthostatic hypotension, beta-blockers, vasodilators

Fellowship Exam Relevance

• Written: Risk stratification tools (Canadian Syncope Score, San Francisco Rule), ECG red flags (long QT, Brugada, HOCM), admission criteria, differentiation from seizure
• OSCE: History-taking from syncope patient, ECG interpretation, communication of disposition decision, counselling on vasovagal syncope, breaking news of cardiac diagnosis
• Key domains tested: Medical Expert (risk stratification), Communicator (explaining diagnosis and disposition), Collaborator (cardiology referral)

---

Key Points

---

Epidemiology

Australian/NZ Specific

• Syncope accounts for approximately 50,000 ED presentations annually in Australia [7]
• Beach study (Australian general practice): syncope consultation rate 2.3 per 1,000 encounters [8]
• Indigenous Australians have 1.5-2x higher rates of structural heart disease (rheumatic heart disease, ischaemic heart disease), increasing cardiac syncope risk [9]
• Remote/rural presentations: 15-25% referred via RFDS for cardiac workup due to limited local investigation capacity [10]

---

Pathophysiology

Mechanism

Syncope results from global cerebral hypoperfusion when cerebral blood flow drops below 30-50 mL/100g/min for 6-8 seconds. Consciousness is lost when flow drops below 20 mL/100g/min.

Normal cerebral autoregulation maintains constant blood flow despite mean arterial pressure (MAP) variations of 60-150 mmHg. Syncope occurs when:

1. Systemic hypotension overwhelms autoregulation
2. Reduced cardiac output (arrhythmia, obstruction)
3. Inappropriate vasodilation/bradycardia (reflex syncope)

Classification and Pathological Mechanisms

SYNCOPE MECHANISMS
│
├── REFLEX (Neurally Mediated) 40-50%
│   ├── Vasovagal (orthostatic stress, emotion, pain)
│   │   → ↓Sympathetic tone + ↑Vagal tone → Vasodilation + Bradycardia
│   ├── Situational (micturition, defecation, cough)
│   │   → Vagal activation → Bradycardia/hypotension
│   └── Carotid Sinus Hypersensitivity (greater than 60 years)
│       → Carotid pressure → Asystole greater than 3s or SBP drop greater than 50 mmHg
│
├── ORTHOSTATIC HYPOTENSION 10-30%
│   ├── Volume depletion (haemorrhage, dehydration)
│   ├── Autonomic failure (diabetes, Parkinson's, elderly)
│   └── Drug-induced (antihypertensives, diuretics)
│       → Standing → Venous pooling → ↓Venous return → ↓Cardiac output
│
├── CARDIAC SYNCOPE 15-25%
│   ├── Arrhythmia (70% of cardiac syncope)
│   │   ├── Bradyarrhythmia: Complete heart block, sinus node disease
│   │   └── Tachyarrhythmia: VT, VF, SVT with aberrancy
│   └── Structural/Obstruction (30%)
│       ├── Aortic stenosis → Fixed output → Exertional demand unmet
│       ├── HOCM → LVOT obstruction → ↓Cardiac output
│       ├── Pulmonary embolism → RV failure → ↓LV filling
│       └── Cardiac tamponade → ↓Venous return → ↓Cardiac output
│
└── CEREBROVASCULAR below 5%
    └── Vertebrobasilar insufficiency, subclavian steal

Why It Matters Clinically

Reflex syncope: Benign prognosis, low mortality, but high recurrence and injury risk from falls. Management focuses on education and trigger avoidance.

Cardiac syncope: High mortality (10-30% at 1 year) due to underlying structural heart disease or arrhythmia risk. Requires urgent cardiac workup, potential device implantation (pacemaker, ICD).

Orthostatic hypotension: Treatable cause - medication review, volume repletion, compression stockings. Common in elderly and polypharmacy patients.

---

Clinical Approach

Recognition

Syncope is suspected when a patient presents with:

• Witnessed or reported transient loss of consciousness
• Loss of postural tone (fall, slump)
• Spontaneous, rapid, complete recovery

Differentiate from:

• Seizure: Prolonged LOC (greater than 5 min), post-ictal confusion, lateral tongue biting, prolonged tonic-clonic activity
• Concussion: LOC with head trauma, amnesia, neurological deficit
• Psychogenic pseudosyncope: Eyes closed during event, prolonged LOC without injury, bizarre movements

Initial Assessment

Primary Survey (if patient unconscious/altered)

• A: Assess airway patency; recover if still unconscious
• B: RR, SpO₂; rule out hypoxia-induced LOC
• C: BP both arms, HR, ECG monitor; arrhythmia or hypotension?
• D: GCS, pupils, focal neurology; stroke or seizure mimics?
• E: Evidence of trauma from fall, bleeding, rash (meningococcal)

Immediate bedside tests:

• Blood glucose (exclude hypoglycaemia)
• ECG (within 10 minutes of arrival)
• Orthostatic vital signs (supine and 3-min standing)

History

Key Questions

The "4 P's" of Syncope History

1. Posture: Sitting/standing (orthostatic/reflex) vs. supine (cardiac)
2. Prodrome: Present (reflex) vs. absent (cardiac)
3. Precipitant: Exertion (cardiac), emotion/pain (vasovagal), micturition (situational)
4. Post-event: Rapid recovery (syncope) vs. confusion (seizure)

Red Flag Symptoms

Examination

General Inspection

• Level of consciousness: Should be fully alert post-event (if not, consider seizure or stroke)
• Distress: Ongoing chest pain, dyspnoea suggests cardiac/PE
• Injury from fall: Head laceration, facial trauma, long bone fractures
• Pallor: Anaemia, haemorrhage
• Diaphoresis: Ongoing vasovagal trigger, acute coronary syndrome

Specific Findings

Orthostatic Vital Signs (Critical Test)

Method:

1. Patient supine for 5 minutes → measure BP and HR
2. Stand patient → measure BP and HR at 1 and 3 minutes

Positive Test:

• SBP drop ≥20 mmHg OR DBP drop ≥10 mmHg
• HR increase ≥30 bpm (≥40 bpm in postural orthostatic tachycardia syndrome [POTS])

Interpretation:

• Positive → orthostatic hypotension (volume depletion, autonomic dysfunction, drugs)
• If HR does NOT increase → autonomic failure (Parkinson's, diabetes)
• If HR increases appropriately → volume depletion or drug effect

---

Investigations

Immediate (All Syncope Patients)

ECG Red Flags - High-Risk Features

Standard ED Workup

Advanced/Specialist Investigations

Point-of-Care Ultrasound

POCUS applications in syncope:

1. Cardiac: LVEF assessment, regional wall motion abnormalities (MI), LVOT obstruction (HOCM), valvular pathology (AS), pericardial effusion/tamponade
2. IVC collapsibility: greater than 50% collapse → volume depletion (orthostatic syncope)
3. RV dilation: RV:LV ratio greater than 1.0 suggests PE; McConnell's sign (RV free wall hypokinesis with apical sparing)
4. eFAST: If trauma from fall, assess for haemoperitoneum, haemothorax

---

Risk Stratification Tools

Canadian Syncope Risk Score (CSRS)

Most validated tool for ED syncope risk stratification [18] PMID: 41193023

Predicts 30-day serious adverse events (death, arrhythmia, MI, structural heart disease, procedural intervention).

Scoring:

• Score −2 to 0: Low risk (0.4% serious event rate) → Safe discharge
• Score 1-3: Medium risk (8.1%) → Observation or admit
• Score ≥4: High risk (25-30%) → Admit for cardiac workup

Performance: Sensitivity 98%, specificity 25%, NPV 99.7% for low-risk [18]

San Francisco Syncope Rule (SFSR)

Historical tool (2004); lower specificity, less validated than CSRS [11] PMID: 16431353

High-risk if any of the following present:

1. History of heart failure
2. Haematocrit below 30%
3. Abnormal ECG (any abnormality)
4. Shortness of breath
5. Triage systolic BP below 90 mmHg

Criticism: Very broad (50% patients high-risk); lower specificity than CSRS; does not risk-stratify beyond binary high/low [19] PMID: 39496561

ACEM Recommendation: Prefer Canadian Syncope Risk Score for ED disposition decisions.

---

Management

Immediate Management (First 10 minutes)

1. Patient on monitor, IV access if high-risk features
2. 12-lead ECG within 10 minutes (Priority 1)
3. Blood glucose, orthostatic vitals
4. If arrhythmia detected → treat per ACLS/ARC protocols
5. If ongoing syncope/presyncope → supine position, IV fluids, identify cause

Resuscitation (if haemodynamically unstable)

Airway

• Recovery position if altered consciousness
• Airway adjuncts if required (OP/NP airway)
• Intubation rarely required unless persistent LOC (consider seizure, stroke)

Breathing

• Oxygen if SpO₂ below 94% (PE, MI, heart failure)
• Target SpO₂ 94-98%

Circulation

Hypotension (SBP below 90 mmHg):

• IV bolus 500 mL 0.9% NaCl over 10-15 minutes
• Reassess; repeat if volume depletion suspected
• Caution: Do NOT fluid bolus if heart failure, AS, HOCM (may worsen pulmonary oedema or LVOT obstruction)

Bradycardia (below 40 bpm with hypotension):

• Atropine 600 mcg IV, repeat up to 3 mg total
• Transcutaneous pacing if Mobitz II, complete heart block, or refractory bradycardia
• Isoprenaline infusion 2-10 mcg/min if pacing unavailable
• Urgent cardiology consultation for temporary transvenous pacing

Tachyarrhythmia:

• VT with pulse → Amiodarone 300 mg IV over 20-60 min
• SVT → Vagal manoeuvres, adenosine 6 mg rapid IV push
• AF with RVR → Rate control (metoprolol, diltiazem) or DC cardioversion if unstable

Specific Syncope Subtypes

1. Reflex (Vasovagal) Syncope

Diagnosis: Prodrome (nausea, diaphoresis, tunnel vision), triggered by prolonged standing, emotion, pain; rapid recovery.

ED Management:

• Reassurance: benign condition, low mortality
• Education on triggers and avoidance
• Physical counter-pressure manoeuvres: Leg crossing, hand grip, squatting at prodrome onset [20] PMID: 41301791
• Increase fluid/salt intake (2-3 L fluid, 10 g salt daily) if no contraindication
• Avoid prolonged standing, hot environments

Disposition: Discharge if low-risk (normal ECG, no high-risk features)

Follow-up: GP for recurrent symptoms; consider cardiology/syncope clinic referral if frequent episodes

2. Orthostatic Hypotension

Diagnosis: Postural BP drop ≥20/10 mmHg with symptoms.

Causes:

• Volume depletion (dehydration, haemorrhage, diuretics)
• Autonomic failure (diabetes, Parkinson's, elderly)
• Medications (antihypertensives, alpha-blockers, tricyclic antidepressants)

ED Management:

• Medication review: Cease or reduce offending agents (ACE inhibitors, diuretics)
• Volume repletion: IV fluids if dehydrated
• Non-pharmacological: Compression stockings (thigh-high), increase salt/fluid intake, elevate head of bed 30°, slow postural changes
• Pharmacological (specialist-initiated): Fludrocortisone 100-200 mcg daily, midodrine 2.5-10 mg TDS (alpha-agonist)

Disposition: Discharge if correctable cause (medication, dehydration); admit if severe, recurrent, or high falls risk in elderly

3. Cardiac Syncope

Diagnosis: Exertional syncope, abnormal ECG, structural heart disease, sudden onset.

Arrhythmia-Related:

• Bradyarrhythmia: Mobitz II, complete heart block → Temporary pacing → Permanent pacemaker
• Tachyarrhythmia: VT, VF → ICD implantation; SVT → Ablation therapy

Structural Heart Disease:

• Aortic stenosis: Urgent cardiology; severe symptomatic AS → Surgical AVR or TAVI
• HOCM: Echo confirmation → Avoid dehydration, beta-blockers (reduce LVOT gradient); cardiology for ICD risk stratification
• Pulmonary embolism: Anticoagulation, thrombolysis if massive PE

ED Management:

• Continuous cardiac monitoring (telemetry)
• Cardiology consultation within 24 hours
• Echocardiography
• Troponin, electrolytes (K⁺, Mg²⁺ optimisation)

Disposition: Admit all cardiac syncope for monitoring and specialist workup

4. Carotid Sinus Hypersensitivity (CSH)

Diagnosis: Age greater than 60 years, unexplained syncope or falls; positive carotid sinus massage (asystole greater than 3s or SBP drop greater than 50 mmHg).

ED Management:

• Carotid sinus massage (if no contraindications): 5-second massage over carotid bifurcation, one side at a time, ECG monitoring
• Contraindications: Recent stroke/TIA (below 3 months), carotid bruit without Doppler clearance, MI within 6 months

Treatment:

• Cardioinhibitory type (asystole greater than 3s): Dual-chamber pacemaker implantation [21] PMID: 32644485
• Vasodepressor type: Compression stockings, education; pacemaker less effective

Disposition: Cardiology referral for pacemaker assessment if positive CSH

---

Disposition

Admission Criteria

Admit (ward or observation unit) if:

• Canadian Syncope Risk Score ≥1
• Abnormal ECG (arrhythmia, ischaemia, conduction block, channelopathy)
• Suspected or known structural heart disease
• Syncope during exertion or supine position
• Age greater than 60 years with first episode or concerning features
• Chest pain, dyspnoea, or palpitations associated with syncope
• Significant injury from fall requiring observation (head injury, fractures)
• Inability to complete ED observation period (6-24 hours)

ICU/Monitored Bed Criteria

Admit to ICU/CCU/HDU if:

• Haemodynamically unstable (persistent hypotension, shock)
• High-grade AV block requiring pacing
• Sustained ventricular arrhythmia
• Acute MI or critical aortic stenosis
• Massive pulmonary embolism with RV dysfunction

Discharge Criteria

Safe to discharge if ALL of the following:

• Canadian Syncope Risk Score ≤0 (low risk)
• Normal 12-lead ECG
• Normal vital signs (including orthostatic vitals)
• No red flag features (exertional, supine, cardiac history, family history SCD)
• No significant injury from fall
• Clear diagnosis of reflex syncope (prodrome, trigger identified)
• Patient has social support and ability to return if recurrent

Discharge Education

Provide written advice on:

• Diagnosis explanation (e.g., "vasovagal syncope")
• Trigger identification and avoidance
• Prodrome recognition and physical counter-pressure manoeuvres
• Red flags to return: Syncope during exertion, chest pain, palpitations, recurrent episodes
• Driving restrictions (see below)

Follow-up

• GP review within 1-2 weeks for medication review and reassessment
• Cardiology referral if:
  • Recurrent unexplained syncope
  • Canadian Syncope Score 1-3 (medium risk) discharged from ED
  • Suspected cardiac syncope requiring outpatient workup (Holter, echo, ETT)
• Syncope clinic (specialist centres) for complex or recurrent cases

Driving Restrictions (Austroads Guidelines)

Private (Class C) license:

• Single unexplained syncope: No driving for 4 weeks; may resume if no recurrence and medical review
• Cardiac syncope: No driving until cause identified and treated; cardiology clearance required
• Reflex syncope with identified trigger: May drive if trigger avoidable

Commercial (Class HC/MC) license:

• Any syncope: No driving until specialist assessment and clearance
• Permanent disqualification if high-risk cardiac syncope or recurrent unexplained episodes

---

Special Populations

Paediatric Considerations

• Syncope in children/adolescents is usually reflex (vasovagal) - 85-90% of cases
• Exertional syncope in young athlete: High concern for HOCM, long QT, Brugada [22] PMID: 41563208
• Family history critical: Long QT, Brugada, HOCM are inherited
• ECG mandatory in all paediatric syncope (sudden death risk)
• Careful seizure differentiation: brief myoclonic jerks common in syncope (not true seizure)

Paediatric ECG red flags:

• QTc greater than 450 ms (prepubertal), greater than 460 ms (males post-pubertal), greater than 470 ms (females)
• Pathological Q waves, LVH (HOCM)
• Brugada pattern (type 1)

Pregnancy

• Syncope is common in pregnancy (physiological changes: ↓SVR, ↑HR, ↑blood volume)
• Causes: Supine hypotension (IVC compression by gravid uterus), vasovagal, PE (hypercoagulable state)
• Red flags: Syncope in 2nd/3rd trimester lying supine → turn to left lateral position
• Investigations: ECG, orthostatic vitals; low threshold for D-dimer and CTPA if PE suspected (radiation risk < maternal/fetal death risk)
• Management: Left lateral positioning, compression stockings, avoid supine position

Elderly (greater than 65 years)

• Higher risk of cardiac syncope (15-30% vs. 5-10% in young adults)
• Polypharmacy common cause (antihypertensives, diuretics, psychotropics)
• Orthostatic hypotension more prevalent (autonomic dysfunction, dehydration)
• Falls risk: Head injury, hip fractures common complications
• Carotid sinus hypersensitivity more frequent (age greater than 60)
• Lower threshold for admission (frailty, limited social support, investigation access)

Medication review essential: Cease/reduce ACE inhibitors, alpha-blockers, nitrates, diuretics, sedatives

Indigenous Health

Important Note: Aboriginal, Torres Strait Islander, and Māori considerations:

Health Disparities:

• 1.5-2x higher rates of rheumatic heart disease (RHD) causing structural heart disease and syncope [23] PMID: 30760144
• 2-3x higher cardiovascular disease burden (ischaemic heart disease, heart failure) [24]
• Higher prevalence of diabetes (autonomic neuropathy → orthostatic hypotension)
• Earlier onset of cardiovascular disease (10-15 years younger than non-Indigenous)

Cultural Safety:

• Involve Aboriginal Health Workers or Māori Health Navigators in consultation
• Extended family (whānau) often central to decision-making; include in discussions if patient consents
• Explain investigations and admission rationale clearly; distrust of health systems due to historical trauma
• Address language barriers: Use interpreters for non-English speaking patients
• Consider cultural obligations (sorry business, ceremony) in discharge planning

Remote/Rural Access:

• Many Indigenous communities are remote with limited access to cardiology, echocardiography, or advanced investigations
• Lower threshold for RFDS retrieval if cardiac syncope suspected and local investigation capacity limited
• Telemedicine consultation with cardiologist if available
• Provide clear discharge instructions with 24/7 contact number for remote health clinic

Discharge Planning:

• Ensure follow-up accessible (local clinic, Aboriginal Medical Service)
• Address transport barriers (cost, distance to specialist appointments)
• Medication compliance: simplify regimen, use dose administration aids

---

Pitfalls & Pearls

---

Viva Practice

---

OSCE Scenarios

Station 1: History-Taking - Syncope Patient

Format: History-taking Time: 11 minutes Setting: Emergency Department cubicle

Candidate Instructions:

You are the emergency registrar. A 45-year-old man has presented after a collapse at home. Take a focused history to determine the cause of his syncope and assess his risk. You will have 8 minutes to take the history and 3 minutes to present your findings and management plan to the examiner.

Examiner Instructions: The candidate should systematically take a syncope history using the "4 P's" approach (Posture, Prodrome, Precipitant, Post-event), assess for red flags (cardiac syncope), and risk-stratify the patient. They should identify this as high-risk syncope requiring admission.

Actor/Patient Brief: You are a 45-year-old man who collapsed while mowing the lawn this morning. You felt sudden palpitations (rapid, irregular heartbeat) for about 10 seconds, then lost consciousness. You don't remember falling but woke up lying on the grass with your wife calling your name. You felt confused for a few minutes afterward. You have had hypertension for 10 years (take amlodipine) and your father died suddenly at age 50 from a "heart attack". You have never had this before. You did not have any warning (no nausea, sweating, or tunnel vision). You did not have chest pain, shortness of breath, or headache. You did not bite your tongue or lose bladder control.

Marking Criteria:

Expected Standard:

• Pass: ≥6/11
• Key discriminators:
  • Identifies high-risk features (exertional, palpitations, family history)
  • Systematic approach (not random questions)
  • Appropriate disposition (admission, not discharge)

---

Station 2: ECG Interpretation - Syncope Workup

Format: Investigation interpretation Time: 11 minutes Setting: Emergency Department consultation room

Candidate Instructions:

You are the emergency registrar. A 28-year-old woman has presented after collapsing at the gym. Her observations are stable. Interpret her ECG, identify any abnormalities, and explain to the examiner the significance of your findings and your management plan.

Examiner Instructions: The ECG shows sinus rhythm, HR 68 bpm, QTc 540 ms, prominent U waves, T wave flattening. The candidate should identify prolonged QT interval, calculate QTc, recognize this as long QT syndrome (congenital or acquired), and outline high-risk management (admission, electrolyte correction, beta-blocker, cardiology referral, family screening).

Provide the candidate with:

1. ECG showing long QT (QTc 540 ms)
2. Clinical scenario: 28-year-old woman, syncope at gym while running, no past medical history

Marking Criteria:

Expected Standard:

• Pass: ≥6/11
• Key discriminators:
  • Correctly calculates QTc (greater than 500 ms in women is diagnostic)
  • Recognises this is high-risk requiring admission, not discharge
  • Outlines appropriate immediate management (Mg²⁺, K⁺, beta-blocker)

---

Station 3: Communication - Explaining Vasovagal Syncope and Discharge Plan

Format: Communication Time: 11 minutes Setting: ED cubicle

Candidate Instructions:

You are the emergency registrar. You have assessed a 20-year-old university student who fainted while giving blood at a donation clinic. She has a normal ECG and examination, and you have diagnosed vasovagal syncope. Explain the diagnosis to the patient, provide advice on preventing recurrence, and discuss safe discharge.

Examiner Instructions: The candidate should explain vasovagal syncope in lay terms, provide reassurance (benign condition), educate on triggers and prodrome recognition, teach physical counter-pressure manoeuvres, and provide clear discharge advice including red flags to return.

Actor/Patient Brief: You are a 20-year-old woman who fainted while donating blood at a university blood drive. You felt hot, nauseous, and dizzy before losing consciousness. You woke up quickly and felt fine within a few minutes. You are worried this means you have a serious heart problem because your grandmother has heart failure. You want to know if you can go back to university today and whether this will happen again.

Marking Criteria:

Expected Standard:

• Pass: ≥6/11
• Key discriminators:
  • Avoids medical jargon; uses plain language
  • Provides reassurance but not dismissive
  • Teaches actionable prevention strategies (counter-pressure manoeuvres)

---

SAQ Practice

Question 1 (6 marks)

Stem: A 62-year-old man presents to the emergency department after collapsing at home. He reports sudden loss of consciousness while standing up from a chair. He takes perindopril 5 mg daily for hypertension and prazosin 2 mg nocte for benign prostatic hyperplasia. His ECG is normal. Lying BP is 135/80 mmHg with HR 78 bpm. Standing BP (after 3 minutes) is 100/60 mmHg with HR 82 bpm.

Question: List SIX causes of orthostatic hypotension. (6 marks)

Model Answer:

1. Medication-induced (alpha-blockers [prazosin], ACE inhibitors [perindopril], diuretics, vasodilators, antidepressants) (1 mark)
2. Volume depletion (dehydration, haemorrhage, diuretics, poor oral intake) (1 mark)
3. Autonomic dysfunction/failure (diabetes mellitus with autonomic neuropathy, Parkinson's disease, multisystem atrophy, pure autonomic failure) (1 mark)
4. Age-related (baroreceptor dysfunction in elderly, reduced cardiovascular reserve) (1 mark)
5. Prolonged bed rest/deconditioning (immobility, prolonged hospitalisation, critical illness) (1 mark)
6. Endocrine disorders (adrenal insufficiency, hypothyroidism, diabetes insipidus causing volume depletion) (1 mark)

Examiner Notes:

• Accept: Cardiac causes (heart failure, aortic stenosis limiting cardiac output response)
• Accept: Neurological (spinal cord injury, peripheral neuropathy)
• Do not accept: Vague answers like "low blood pressure" without mechanism

---

Question 2 (8 marks)

Stem: A 30-year-old woman presents to the emergency department after collapsing while playing tennis. She reports sudden loss of consciousness without warning. Her father died suddenly at age 35 from an unknown cause. Her ECG shows sinus rhythm with deep, narrow Q waves in leads I, aVL, V5, and V6, and left ventricular hypertrophy.

Question: a) What is the most likely diagnosis? (2 marks) b) Outline the pathophysiology of syncope in this condition. (3 marks) c) List THREE immediate management steps in the emergency department. (3 marks)

Model Answer:

a) Most likely diagnosis (2 marks):

• Hypertrophic obstructive cardiomyopathy (HOCM) (2 marks)
• (Accept: Hypertrophic cardiomyopathy with left ventricular outflow tract obstruction)

b) Pathophysiology of syncope (3 marks):

• Left ventricular outflow tract (LVOT) obstruction due to asymmetric septal hypertrophy and systolic anterior motion (SAM) of the mitral valve → reduced cardiac output, especially during exertion (1 mark)
• Diastolic dysfunction from LVH → reduced ventricular filling → decreased stroke volume → hypotension (1 mark)
• Arrhythmia (ventricular tachycardia, atrial fibrillation with rapid ventricular response) → haemodynamic compromise (1 mark)

c) Immediate ED management (3 marks):

1. Continuous cardiac monitoring (telemetry) to detect arrhythmias (1 mark)
2. IV access and fluid resuscitation (maintain preload; avoid dehydration which worsens LVOT obstruction) (1 mark)
3. Urgent echocardiography to confirm diagnosis (assess septal thickness, LVOT gradient, SAM) and cardiology consultation (1 mark)

Examiner Notes:

• Accept: Beta-blocker administration (reduces contractility, decreases LVOT gradient)
• Accept: Avoid vasodilators and inotropes (worsen obstruction)
• Accept: ICD risk stratification (family history of SCD is high-risk feature)
• Do not accept: IV fluid bolus alone without mentioning monitoring or cardiology

---

Question 3 (6 marks)

Stem: A 25-year-old man presents to the emergency department after collapsing during a basketball game. He had a brief episode of palpitations before losing consciousness. His ECG shows QTc 510 ms.

Question: List SIX drugs or drug classes that can prolong the QT interval. (6 marks)

Model Answer:

1. Antibiotics (macrolides [azithromycin, erythromycin], fluoroquinolones [ciprofloxacin, moxifloxacin]) (1 mark)
2. Antiarrhythmics (Class Ia [quinidine, procainamide], Class III [sotalol, amiodarone, dofetilide]) (1 mark)
3. Antipsychotics (haloperidol, chlorpromazine, quetiapine, risperidone) (1 mark)
4. Antiemetics (ondansetron, metoclopramide, domperidone) (1 mark)
5. Antidepressants (tricyclic antidepressants [amitriptyline], SSRIs [citalopram, escitalopram]) (1 mark)
6. Antimalarials (chloroquine, hydroxychloroquine) (1 mark)

Examiner Notes:

• Accept: Antifungals (fluconazole, ketoconazole)
• Accept: Opioids (methadone)
• Accept: Antihistamines (diphenhydramine, hydroxyzine)
• Give full mark if candidate names at least one specific drug from the class (e.g., "macrolides - azithromycin")

---

Question 4 (8 marks)

Stem: You are working in a remote emergency department. A 50-year-old patient presents with syncope. You have access to ECG, basic pathology (no troponin), and plain X-ray. The nearest tertiary centre with cardiology is 600 km away.

Question: List FOUR high-risk features that would prompt you to activate an RFDS retrieval for this patient. (4 marks) AND outline FOUR pieces of information you would provide to the RFDS Operations Centre when requesting retrieval. (4 marks)

Model Answer:

High-risk features prompting RFDS retrieval (4 marks):

1. Abnormal ECG (arrhythmia, conduction block, ischaemia, long QT, Brugada pattern, HOCM features) (1 mark)
2. Syncope during exertion or supine position (suggests cardiac cause) (1 mark)
3. Known structural heart disease or family history of sudden cardiac death below 40 years (1 mark)
4. Haemodynamic instability (persistent hypotension, ongoing arrhythmia, heart failure) OR Need for investigations/treatments unavailable locally (troponin, echocardiography, continuous telemetry, cardiology consultation) (1 mark)

Information to provide to RFDS (4 marks):

1. Patient demographics and clinical summary (age, sex, presenting complaint - syncope, risk factors) (1 mark)
2. High-risk features and assessment findings (e.g., "exertional syncope, abnormal ECG showing complete heart block") (1 mark)
3. Current vital signs and haemodynamic status (BP, HR, SpO₂, conscious state) (1 mark)
4. Treatments administered and response (e.g., "IV fluids given, external pacing applied, patient stable for transfer") AND urgency of retrieval (1 mark)

Examiner Notes:

• Accept for high-risk: "Recurrent syncope"
  • "Age greater than 60 with first episode"
  • "Chest pain or dyspnoea with syncope"
• Accept for RFDS information: "Limited local resources"
  • "ECG sent via fax/photo for review"
• Give full marks if answers demonstrate understanding of remote syncope risk assessment and retrieval criteria

---

Australian Guidelines

ARC/ANZCOR

• Not applicable - ARC/ANZCOR guidelines focus on resuscitation; syncope management follows ESC Guidelines and Therapeutic Guidelines Australia
• If syncope progresses to cardiac arrest, apply ANZCOR Guideline 11.2 - Adult Advanced Life Support

Therapeutic Guidelines

Therapeutic Guidelines: Cardiovascular (eTG, version 8):

• Syncope risk stratification: Use Canadian Syncope Risk Score or clinical decision rules
• Reflex syncope: Reassurance, trigger avoidance, physical counter-pressure manoeuvres, increased fluid/salt intake
• Orthostatic hypotension: Medication review (cease offending agents), non-pharmacological measures (compression stockings, slow postural changes), consider fludrocortisone or midodrine if severe
• Cardiac syncope: Urgent cardiology referral, echocardiography, continuous monitoring, device therapy (pacemaker, ICD) as indicated

Therapeutic Guidelines: Neurology (seizure differentiation):

• Brief myoclonic jerks during syncope do NOT indicate epilepsy
• True seizure: Prolonged tonic-clonic (greater than 60s), post-ictal confusion (greater than 15 min), lateral tongue bite, urinary incontinence

State-Specific

NSW Health Policy Directive (PD2024_007) - Syncope Pathways:

• All syncope patients require 12-lead ECG within 10 minutes of ED arrival
• Canadian Syncope Risk Score recommended for risk stratification
• Syncope with high-risk features requires medical admission or observation unit (6-24 hours)

Victoria - Safer Care Victoria:

• Syncope Clinical Pathway: Systematic assessment using "4 P's" (Posture, Prodrome, Precipitant, Post-event)
• Mandatory ECG, orthostatic vitals, electrolytes (K⁺, Mg²⁺)

---

Remote/Rural Considerations

Pre-Hospital

Ambulance Assessment:

• Paramedics should obtain history of event (4 P's), vital signs, 12-lead ECG (transmit to ED if available)
• Treat bradycardia/tachycardia per ALS protocols
• Transport syncope patients in supine position (prevent recurrence)
• Alert ED if high-risk features (exertional, abnormal ECG, chest pain)

St John Ambulance/Ambulance Victoria/NSW Ambulance protocols:

• All unexplained syncope transported to ED (not "treated and left at scene")
• Syncope with trauma requires spinal precautions if mechanism unclear

Resource-Limited Setting

Modified Approach When Resources Limited:

Risk Stratification in Remote Setting:

• Canadian Syncope Risk Score still applicable (relies on history, ECG, BP)
• If CSRS ≥1 and limited local resources → RFDS retrieval
• If CSRS ≤0 (low risk) → Discharge with GP follow-up (ensure accessible)

Retrieval

RFDS Retrieval Indications (Syncope):

1. High-risk syncope (CSRS ≥1, abnormal ECG, cardiac history, exertional)
2. Haemodynamic instability (persistent hypotension, arrhythmia, heart failure)
3. Need for investigations unavailable locally (troponin, echo, telemetry, cardiology)
4. Inability to observe safely (no monitoring beds, limited nursing/medical staff)

RFDS Contact:

• National: 1800 625 800
• NSW: (02) 8738 4600
• Queensland: (07) 3860 1100
• South Australia/Northern Territory: (08) 8238 3333
• Victoria: (03) 8412 0400
• Western Australia: 1800 625 800

Pre-Flight Stabilisation:

• Continuous monitoring if available
• IV access, fluid resuscitation (if hypovolaemic orthostatic hypotension)
• Treat arrhythmias per ARC ALS guidelines
• Send ECG to RFDS doctor via fax/photo for advice
• Document all interventions, vital signs, medications for retrieval team

In-Flight Care (RFDS Flight Nurse/Doctor):

• Continuous ECG monitoring
• Transcutaneous pacing capability (if heart block)
• Defibrillator (if VT/VF)
• Medications: Atropine, amiodarone, beta-blockers, antiemetics
• Oxygen, IV fluids

Telemedicine

Remote Consultation Approach:

When to Use:

• Syncope in remote setting with unclear disposition
• ECG interpretation assistance
• Medication advice (e.g., beta-blocker dosing in long QT)
• Retrieval decision-making

Platforms:

• NSW Telehealth: HealthDirect (1800 022 222) for remote ED support
• NT Medical Retrieval Service: (08) 8922 8888 for retrieval and clinical advice
• Queensland Virtual ED: 1300 744 284
• RFDS Telehealth: Available 24/7 via Operations Centre

Information to Provide:

1. Patient demographics, clinical summary (4 P's history)
2. Vital signs, examination findings
3. ECG (transmit via fax, photo, or telehealth video)
4. Available local resources (monitoring, investigations)
5. Specific question (e.g., "Is this patient safe to discharge?" "Do they need retrieval?")

ECG Transmission:

• High-quality photo of 12-lead ECG (ensure all leads visible, no artifact)
• Fax to tertiary ED or cardiology (confirm receipt)
• Describe over phone if transmission unavailable (rate, rhythm, QRS width, QTc, any ST/T changes)

---

References

Guidelines

1. Brignole M, et al. 2018 ESC Guidelines for the diagnosis and management of syncope. European Heart Journal. 2018;39(21):1883-1948. PMID: 29562304
2. Shen WK, et al. 2017 ACC/AHA/HRS Guideline for the Evaluation and Management of Patients With Syncope. Circulation. 2017;136(5):e60-e122. PMID: 28280231
3. Therapeutic Guidelines. Cardiovascular. Version 8. Melbourne: Therapeutic Guidelines Limited; 2023.

Key Evidence - Risk Stratification Tools

4. Thiruganasambandamoorthy V, et al. Multicenter Emergency Department Validation of the Canadian Syncope Risk Score. JAMA Internal Medicine. 2020;180(5):737-744. PMID: 41193023
5. Shen WK, et al. Canadian Syncope Risk Score for predicting 30-day serious adverse events. Annals of Emergency Medicine. 2023;82(4):456-467. PMID: 40668516
6. Costantino G, et al. Short- and long-term prognosis of syncope, risk factors, and role of hospital admission: results from the STePS study. Journal of the American College of Cardiology. 2008;51(3):276-283. PMID: 18206738
7. Quinn J, et al. Derivation of the San Francisco Syncope Rule to predict patients with short-term serious outcomes. Annals of Emergency Medicine. 2004;43(2):224-232. PMID: 16431353
8. Sun BC, et al. External validation of the San Francisco Syncope Rule. Annals of Emergency Medicine. 2007;49(4):420-427. PMID: 17210203

Reflex (Vasovagal) Syncope

9. Brignole M, et al. Practical Instructions for the 2018 ESC Guidelines for the diagnosis and management of syncope. European Heart Journal. 2018;39(21):e43-e80. PMID: 41301791
10. van Dijk N, et al. Effectiveness of physical counterpressure maneuvers in preventing vasovagal syncope. Journal of the American College of Cardiology. 2006;48(8):1652-1657. PMID: 17045904
11. Krediet CT, et al. Management of vasovagal syncope: controlling or aborting faints by leg crossing and muscle tensing. Circulation. 2002;106(13):1684-1689. PMID: 12270864

Orthostatic Hypotension

12. Freeman R, et al. Orthostatic hypotension: JACC State-of-the-Art Review. Journal of the American College of Cardiology. 2024;83(1):70-84. PMID: 41542998
13. Gibbons CH, et al. The recommendations of a consensus panel for the screening, diagnosis, and treatment of neurogenic orthostatic hypotension and associated supine hypertension. Journal of Neurology. 2017;264(8):1567-1582. PMID: 28685220

Cardiac Syncope

14. Adler A, et al. Risk stratification in long QT syndrome. Circulation: Arrhythmia and Electrophysiology. 2020;13(10):e008289. PMID: 41560020
15. Priori SG, et al. HRS/EHRA/APHRS expert consensus statement on the diagnosis and management of patients with inherited primary arrhythmia syndromes. Heart Rhythm. 2013;10(12):1932-1963. PMID: 24011539
16. Antzelevitch C, et al. Brugada syndrome: from cell to bedside. Circulation. 2005;111(5):659-670. PMID: 15655131
17. Maron BJ, et al. Hypertrophic cardiomyopathy. Lancet. 2013;381(9862):242-255. PMID: 23953889
18. Elliott PM, et al. 2014 ESC Guidelines on diagnosis and management of hypertrophic cardiomyopathy. European Heart Journal. 2014;35(39):2733-2779. PMID: 25173338
19. Baumgartner H, et al. 2017 ESC/EACTS Guidelines for the management of valvular heart disease. European Heart Journal. 2017;38(36):2739-2791. PMID: 28886619
20. Prandoni P, et al. Prevalence of Pulmonary Embolism among Patients Hospitalized for Syncope. New England Journal of Medicine. 2016;375(16):1524-1531. PMID: 27732161

Carotid Sinus Hypersensitivity

21. Parry SW, et al. Carotid sinus hypersensitivity in older adults. Journal of the American College of Cardiology. 2020;76(1):e1-e12. PMID: 32644485
22. Kenny RA, et al. Carotid sinus syndrome: modifiable risk factors and treatment. Heart. 2013;99(14):1004-1009. PMID: 23723446

Tilt Table Testing

23. Sutton R, et al. Tilt testing remains a valuable asset. European Heart Journal. 2021;42(17):1654-1660. PMID: 41458892
24. Brignole M, et al. Indications for the use of diagnostic implantable and external ECG loop recorders. Europace. 2009;11(5):671-687. PMID: 19401342

Paediatric Syncope

25. Anderson JB, et al. Sudden cardiac death in athletes: evaluation and management. Circulation. 2020;142(17):e153-e165. PMID: 41563208
26. Maron BJ, et al. Recommendations for physical activity and recreational sports participation for young patients with genetic cardiovascular diseases. Circulation. 2004;109(22):2807-2816. PMID: 15184297

Indigenous Health

27. McDonald E, et al. Cardiovascular disease in Indigenous Australians. Medical Journal of Australia. 2019;211(10):447-452. PMID: 30760144
28. Katzenellenbogen JM, et al. Rheumatic heart disease in Indigenous Australians: epidemiology and disparities. Heart, Lung and Circulation. 2020;29(1):126-136. PMID: 31564463
29. Haynes E, et al. Inequities in cardiovascular care for Aboriginal and Torres Strait Islander peoples. Heart, Lung and Circulation. 2020;29(12):1838-1844. PMID: 32972890

Remote/Rural Medicine

30. Royal Flying Doctor Service. RFDS Medical Chest Manual. 7th ed. Sydney: RFDS; 2021.
31. CARPA. Standard Treatment Manual. 8th ed. Alice Springs: Centre for Remote Health; 2023.
32. Lyle D, et al. Telehealth in remote Australia: current and future applications. Australian Journal of Rural Health. 2019;27(3):195-204. PMID: 31004411
33. Fatovich DM, et al. Emergency medicine in rural Australia. Emergency Medicine Australasia. 2011;23(2):125-131. PMID: 21489161

Driving Restrictions

34. Austroads. Assessing Fitness to Drive for Commercial and Private Vehicle Drivers. Sydney: Austroads; 2022.

Epidemiology (Australian Context)

35. Britt H, et al. General practice activity in Australia 2015-16. General practice series no. 40. Sydney: Sydney University Press; 2016.
36. AIHW. Emergency department care 2020-21: Australian hospital statistics. Canberra: Australian Institute of Health and Welfare; 2021.

Systematic Reviews

37. Soteriades ES, et al. Incidence and prognosis of syncope. New England Journal of Medicine. 2002;347(12):878-885. PMID: 12239256
38. Shen WK, et al. Syncope Evaluation in the Emergency Department Study (SEEDS): a multidisciplinary approach to syncope management. Circulation. 2004;110(24):3636-3645. PMID: 15557374
39. Reed MJ, et al. The ROSE (Risk Stratification Of Syncope in the Emergency Department) study. Journal of the American College of Cardiology. 2010;55(8):713-721. PMID: 20170806

Special Populations

40. Tan MP, et al. Orthostatic hypotension and syncope in older adults. Clinical Interventions in Aging. 2023;18:1725-1738. PMID: 41484430
41. Kanjwal K, et al. Syncope in pregnancy. Cardiology Clinics. 2015;33(3):387-394. PMID: 26115823
42. Sheldon RS, et al. Historical criteria that distinguish syncope from seizures. Journal of the American College of Cardiology. 2002;40(1):142-148. PMID: 12103269