Syncope & Transient Loss of Consciousness

📋 Key Information Summary

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Syncope is a transient loss of consciousness (TLOC) due to global cerebral hypoperfusion, with rapid onset, short duration, and spontaneous complete recovery.
Cardiac syncope carries the highest mortality risk (up to 30% 1-year mortality in structural heart disease) and always warrants urgent investigation and often admission.
Reflex (vasovagal) syncope is the most common cause overall, typically benign, and managed with education, trigger avoidance, and physical counterpressure manoeuvres.
Orthostatic hypotension is diagnosed with a sustained drop in systolic BP ≥20 mmHg or diastolic BP ≥10 mmHg within 3 minutes of standing, or systolic BP <90 mmHg.
A 12-lead ECG is mandatory for every episode of TLOC; abnormal ECG findings (prolonged QT, Brugada pattern, AV block, ventricular pre-excitation) mandate urgent cardiology referral.
High-risk features requiring admission include syncope during exertion or while supine, family history of sudden cardiac death <40 years, new or unexplained dyspnoea, severe structural/coronary heart disease, and haemodynamic instability.
Neuroimaging and EEG are NOT routine for syncope; order only when there are focal neurological signs, prolonged confusion, or features suggestive of seizure or stroke.
Medication review is essential — antihypertensives, diuretics, antidepressants, and antipsychotics are common iatrogenic contributors to orthostatic and reflex syncope.
Driving restrictions apply: Austroads guidelines recommend ≥1 month off driving for a single unexplained syncope episode, and ≥6–12 months for recurrent or cardiac syncope.
In Aboriginal and Torres Strait Islander populations, delayed presentation, higher burden of cardiovascular disease, and remote access barriers increase syncope-related morbidity and mortality.
Orthostatic vital signs (lying and standing BP/HR at 1 and 3 minutes) should be performed in every patient presenting with syncope unless the cause is clearly vasovagal.

Introduction & Australian Epidemiology

Transient loss of consciousness (TLOC) is defined as a spontaneous, temporary loss of consciousness with complete recovery. Syncope — TLOC due to global cerebral hypoperfusion — accounts for approximately 1–3% of all emergency department (ED) presentations in Australia and up to 6% of acute medical admissions. It is a leading cause of hospital referral from primary care and carries significant diagnostic and prognostic complexity.

In Australia, syncope-related ED presentations total over 100,000 annually, with a peak incidence in older adults (>65 years). The direct healthcare cost is substantial: approximately $2.4 billion per year including ambulance transport, ED attendance, inpatient investigation, and specialist follow-up. Up to 40% of patients remain undiagnosed after initial ED evaluation.

The differential diagnosis is broad and includes true syncope (cardiac, reflex, orthostatic), epileptic seizures, psychogenic pseudosyncope, and rare causes such as subarachnoid haemorrhage or vertebrobasilar ischaemia. Accurate classification is critical because prognosis and management differ dramatically.

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Diagnostic pitfall: Approximately 20% of patients initially diagnosed with syncope actually have an alternative diagnosis (seizure, concussion, intoxication). Always consider non-syncopal causes in the differential.

Classification of TLOC

Type	Mechanism	Proportion	Mortality Risk
Reflex (vasovagal)	Inappropriate vasodilation ± bradycardia	~40–60%	Very low
Orthostatic hypotension	Inadequate compensatory vasoconstriction on standing	~10–30%	Low–moderate
Cardiac syncope	Arrhythmia, structural disease, or acute cardiac event	~10–20%	High (up to 30% at 1 year)
Unknown / unexplained	Uncertain despite evaluation	~15–30%	Variable

Pathophysiology

Cerebral autoregulation normally maintains constant cerebral blood flow (CBF) across a mean arterial pressure (MAP) range of approximately 60–150 mmHg. Syncope occurs when MAP falls below the lower autoregulatory threshold, typically at a systolic BP of ~50–60 mmHg, causing global cerebral hypoperfusion lasting >6–8 seconds.

Reflex (Vasovagal) Syncope

Triggered by prolonged standing, emotional distress, pain, or venepuncture. The Bezold–Jarisch reflex mediates a paradoxical bradycardia and vasodilation via vagal afferents. Prodromal symptoms (nausea, pallor, diaphoresis, visual dimming) are typical and reflect the gradual haemodynamic decline. Tilt-table testing can provoke this response in susceptible individuals.

Orthostatic Hypotension

Gravity-dependent pooling of 500–1000 mL of blood in the lower limbs on standing reduces venous return. Normally, baroreceptors in the carotid sinus and aortic arch trigger sympathetic activation to maintain BP. Failure of this reflex — due to autonomic neuropathy (diabetes, Parkinson disease), volume depletion, or vasodilatory medications — results in sustained hypotension.

Cardiac Syncope

Arrhythmic syncope (bradyarrhythmias, supraventricular tachycardia, ventricular tachycardia) reduces cardiac output abruptly. Structural causes (aortic stenosis, hypertrophic cardiomyopathy, cardiac tamponade, pulmonary embolism) limit the heart's ability to increase output in response to demand. Both mechanisms produce sudden-onset LOC often without prodrome.

History & Risk Stratification

A thorough history is the single most important diagnostic tool in syncope. Witnesses should be contacted where possible. The history should aim to classify syncope as reflex, orthostatic, or cardiac, and identify high-risk features that mandate admission and urgent investigation.

Essential Historical Features

Domain	Suggests Reflex Syncope	Suggests Cardiac Syncope	Suggests Orthostatic
Position	Prolonged standing, sitting upright	Supine or during exertion	Immediately on standing
Prodrome	Nausea, warmth, pallor, diaphoresis (>30 sec)	None or brief palpitations	Gradual lightheadedness, visual greying
Onset	Gradual	Sudden	Seconds after postural change
Recovery	Rapid, no confusion	May be prolonged if low cardiac output	Rapid once supine
Triggers	Pain, emotion, warm environment, venepuncture	Exertion, chest pain preceding	Dehydration, medications, morning
Injury	Infrequent (often collapsed onto something)	Common (sudden LOC, lacerations)	Occasional

High-Risk Clinical Features

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Admit and investigate urgently if ANY of the following are present:

Syncope during exertion or while supine
Family history of sudden cardiac death at <40 years of age
New or unexplained dyspnoea
Severe structural heart disease or known reduced ejection fraction
ECG abnormalities: sustained ventricular tachycardia, high-degree AV block, Brugada pattern, long QTc (>500 ms), ventricular pre-excitation, Q waves suggesting infarction
Persistent hypotension (systolic <90 mmHg)
Syncope associated with chest pain or palpitations
Severe aortic stenosis or hypertrophic cardiomyopathy

Risk Stratification Tools

The San Francisco Syncope Rule and the Canadian Syncope Risk Score (CSRS) assist in identifying patients safe for discharge. The CSRS stratifies patients into low (≤−1), medium (0–3), and high (≥4) risk categories at 30 days for serious adverse events. In Australian EDs, clinical gestalt combined with ECG findings remains the predominant approach, supplemented by these validated scores.

Low Risk

Typical Vasovagal

Clear prodrome, classic trigger, normal ECG, no cardiac history, age <40, no injury. CSRS ≤ −1.

Setting: Discharge with GP follow-up in 1–2 weeks

Moderate Risk

Uncertain Aetiology

Age >40, single non-specific ECG abnormality, medication-related, no high-risk features. CSRS 0–3.

Setting: ED observation ± short-stay unit, outpatient investigation

High Risk

Suspected Cardiac Syncope

Exertional or supine syncope, abnormal ECG, structural heart disease, family history SCD <40, recurrent episodes. CSRS ≥ 4.

Setting: Inpatient admission, telemetry, urgent cardiology consultation

History Red Flags — Seizure vs Syncope Differentiation

Feature	Syncope	Seizure
Tongue biting	Lateral tip (if at all)	Lateral tongue (highly specific)
Duration of LOC	<30 seconds typically	>1–2 minutes
Tonic-clonic movements	Brief myoclonic jerks (<15 sec) may occur	Sustained >15 seconds, rhythmic
Postictal confusion	Rapid recovery, no confusion	Prolonged (>5 min) confusion/drowsiness
Cyanosis	Pallor	Cyanosis during event
Incontinence	Rare (urinary only)	Urinary ± faecal, more common

Basic Workup

The workup should be targeted and guided by the clinical history and risk stratification. Routine extensive investigation of every syncopal episode is low-yield and not cost-effective. Australian emergency and primary care guidelines recommend a stepwise approach.

Core Investigations

Essential

12-Lead ECG

Mandatory for every TLOC episode. Detects arrhythmia, conduction disease, ischaemia, QT prolongation, Brugada pattern, Wolff-Parkinson-White (WPW). MBS item 11704 (approx. $27.50).

Essential

Orthostatic Blood Pressure and Heart Rate

Measure lying (≥5 min supine) then standing at 1 minute and 3 minutes. Positive if systolic BP drop ≥20 mmHg, diastolic BP drop ≥10 mmHg, or systolic BP <90 mmHg on standing. Heart rate increase >30 bpm suggests postural orthostatic tachycardia syndrome (POTS).

Essential

Capillary Blood Glucose

Hypoglycaemia (<4.0 mmol/L) is a readily reversible cause of TLOC. Perform at point of care in all presentations.

Available

Full Blood Count (FBC)

Anaemia (Hb <100 g/L) may contribute to or exacerbate syncope. MBS item 65060.

Available

Urea, Electrolytes & Creatinine (UEC)

Dehydration, hyponatraemia, hyperkalaemia, renal impairment. MBS item 66515.

Available

Troponin (High-Sensitivity)

If cardiac syncope suspected or chest pain present. Not routine for classic vasovagal episodes. MBS item 66533.

Available

Continuous Cardiac Monitoring / Telemetry

For moderate-to-high risk patients during ED observation or inpatient stay. Duration ≥24 hours if arrhythmic syncope suspected.

Available

Holter / Ambulatory ECG Monitor (24–72 hours)

For recurrent unexplained syncope with low-to-moderate risk. Consider external loop recorder (up to 30 days) or implantable loop recorder (ILR, up to 3 years) for infrequent episodes. MBS item 11710.

Available

Echocardiography

If structural heart disease suspected (murmur, abnormal ECG, cardiac history). Identifies aortic stenosis, hypertrophic cardiomyopathy, reduced EF, right heart strain. MBS item 55114.

Specialist

Tilt-Table Test

For recurrent unexplained syncope where reflex syncope is suspected but history is atypical. Performed under cardiology supervision. Sensitivity ~60–80%, specificity ~90%.

Specialist

Electrophysiology Study (EPS)

For suspected arrhythmic syncope with structural heart disease or abnormal ECG where non-invasive testing is inconclusive. Accessible in tertiary centres.

Neuroimaging and EEG — When to Order

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Do not routinely order neuroimaging or EEG for syncope. Yield is <1% when no focal neurological signs are present. These investigations are indicated only when there are clinical features suggesting an alternative diagnosis (seizure, stroke, subarachnoid haemorrhage).

Investigation	Indication	When NOT to Order
CT Brain (non-contrast)	Head injury from syncope, focal neuro signs, suspected SAH, anticoagulated patient with trauma	Routine syncope workup without red flags
MRI Brain	Focal neuro deficit, suspected posterior fossa lesion, recurrent unexplained TLOC with seizure features	Classic vasovagal syncope, orthostatic hypotension
CT Angiography (head/neck)	Suspected vertebrobasilar ischaemia, posterior circulation TIA features	Typical syncope without vertebrobasilar symptoms
EEG	Prolonged post-event confusion (>5 min), witnessed tonic-clonic activity >15 sec, recurrent unexplained LOC with seizure features, tongue biting (lateral)	Brief myoclonic jerks during syncope, classic vasovagal, orthostatic syncope

Recommended Initial Workup Pathway

1

All Patients

History (witness account), examination, 12-lead ECG, orthostatic vitals, BGL. Classify as likely reflex / orthostatic / cardiac / unexplained.

2

If Cardiac Features Present

Continuous telemetry, high-sensitivity troponin, FBC, UEC. Cardiology consultation. Echocardiography if structural disease suspected.

3

If Recurrent Unexplained

Holter monitor (24–72 h) or external loop recorder. If still unexplained, implantable loop recorder (ILR). Tilt-table test if reflex syncope suspected.

4

If Seizure Suspected

EEG, neurology referral. CT/MRI brain if focal signs or atypical features. Consider video-EEG monitoring.

Clinical Presentation & Diagnostic Criteria

Reflex (Vasovagal) Syncope

Classic presentation: young adult in a warm, crowded environment, or in the setting of pain, emotion, or venepuncture. Prodrome of nausea, pallor, lightheadedness, and visual dimming for 30 seconds to a few minutes, followed by LOC lasting <30 seconds. Rapid recovery with no postictal features. Three subtypes: vasodepressor (predominant hypotension), cardioinhibitory (predominant bradycardia/asystole), and mixed.

Situational Syncope

A subtype of reflex syncope triggered by specific situations: micturition syncope (nocturnal, male), defaecation syncope, cough syncope (COPD, smokers), swallowing syncope, post-exercise syncope. Each has a distinct vagal trigger mechanism.

Carotid Sinus Syncope

Predominantly in men >50 years. Reproducible syncope or presyncope with carotid sinus massage — defined as asystole >3 seconds and/or systolic BP drop >50 mmHg. Diagnosed by carotid sinus massage under continuous monitoring. Must exclude significant carotid stenosis prior to testing.

Orthostatic Hypotension

Diagnosed when systolic BP falls ≥20 mmHg or diastolic BP falls ≥10 mmHg within 3 minutes of standing, or any systolic BP <90 mmHg on standing. Initial orthostatic hypotension occurs within 15 seconds of standing (common in young men), while classical orthostatic hypotension occurs at 1–3 minutes. Delayed orthostatic hypotension (>3 minutes) may indicate progressive autonomic failure.

Cardiac Arrhythmic Syncope

Bradyarrhythmic syncope (sinus node dysfunction, high-degree AV block, pacemaker malfunction) or tachyarrhythmic syncope (VT, SVT with rapid ventricular response, torsades de pointes). Typically sudden onset, may occur supine, minimal or no prodrome. Recovery may be rapid but associated with injury. The ECG or cardiac monitor is often diagnostic.

Structural Cardiac Causes

Aortic stenosis (exertional syncope + systolic murmur), hypertrophic cardiomyopathy (young athlete, family history SCD), cardiac tamponade (raised JVP, pulsus paradoxus), acute pulmonary embolism (pleuritic chest pain, tachycardia, hypoxia), aortic dissection (tearing chest pain, BP differential).

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Sudden cardiac death risk: Syncope in hypertrophic cardiomyopathy or with known ventricular dysfunction (EF <35%) should be evaluated for ICD implantation. Refer urgently to cardiology.

Management Strategies

Acute Management of Syncope in the ED

1

Resuscitation & Positioning

Supine, legs elevated (Trendelenburg if tolerated). Secure airway, high-flow O₂ if SpO₂ <94%. IV access. Continuous monitoring.

2

12-Lead ECG

Obtain within 10 minutes. Review for arrhythmia, ischaemia, conduction disease, long QT, Brugada pattern, WPW.

3

Determine Aetiology & Risk

History + ECG + orthostatic vitals + BGL. Apply CSRS or clinical gestalt. Classify as low / moderate / high risk.

4

Admit or Discharge

High risk → inpatient telemetry bed. Moderate risk → ED observation (6–12 hours). Low risk → discharge with GP follow-up.

Management by Syncope Type

Reflex (Vasovagal) Syncope

Management is primarily non-pharmacological and patient education is the cornerstone. Most patients require no medication.

Non-Pharmacological Interventions

Education: Reassurance, explanation of benign nature, recognition of prodromal symptoms
Trigger avoidance: Prolonged standing, dehydration, warm/crowded environments, excessive alcohol
Increase fluid intake: 2–3 L water/day (1.5 L bolus over 15 min before prolonged standing on waking)
Increase dietary salt: 6–10 g NaCl/day (unless contraindicated by hypertension, heart failure, renal disease)
Physical counterpressure manoeuvres (PCM): Leg crossing with muscle tensing, squatting, handgrip exercises — effective in prodromal phase
Tilt training: Standing against a wall for 15–30 min daily — limited evidence but low risk

Pharmacological Options (when non-pharmacological measures fail)

Midodrine: 5–10 mg PO TDS (avoid late evening dose). α₁-agonist. PBS Authority Required (Section 100). Evidence: moderate, reduces syncope burden in recurrent vasovagal syncope.
Fludrocortisone: 0.1–0.2 mg PO daily. Mineralocorticoid. Volume expansion. PBS General Benefit. Limited evidence in vasovagal syncope; more useful in orthostatic hypotension.
SSRIs (sertraline, paroxetine): Small studies suggest benefit. Not first-line. May modulate central serotonergic pathways involved in autonomic control.

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Midodrine

Gutron® · α₁-adrenergic agonist

Adult dose 2.5–10 mg PO TDS (morning, midday, late afternoon; avoid within 4 h of bedtime)

Paediatric dose Not established; specialist use only

Renal adjustment Use with caution if eGFR <30 mL/min; no formal dose adjustment

Hepatic adjustment Use with caution; active metabolite (desglymidodrine) not hepatically metabolised

PBS status ⚠ Authority Required (S100)

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Fludrocortisone

Florinef® · Mineralocorticoid

Adult dose 0.1–0.2 mg PO mane

Paediatric dose 0.05–0.1 mg PO mane; specialist guidance

Renal adjustment Use cautiously; monitor potassium, fluid retention

Hepatic adjustment No specific adjustment; monitor

PBS status ✔ PBS General Benefit

Orthostatic Hypotension

Treat underlying cause: Volume repletion (IV normal saline if dehydrated), correct anaemia, review and withdraw offending medications.
Non-pharmacological: Rise slowly, avoid prolonged recumbency, elastic compression stockings (waist-high), sleep with head of bed elevated 10–20°, increase fluid (2–3 L/day) and salt intake (8–10 g/day), squat to stand manoeuvres.
Pharmacological: Midodrine 5–10 mg PO TDS (first-line), fludrocortisone 0.1–0.2 mg PO mane (second-line, monitor for hypertension and hypokalaemia), droxidopa 100–600 mg PO TDS (specialist use, limited PBS access).

Cardiac Syncope — Definitive Treatment

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Cardiac syncope requires treatment of the underlying cause. Empirical treatment without a diagnosis is inadequate and potentially dangerous. Always involve cardiology.

Cause	Treatment
Sick sinus syndrome	Permanent pacemaker (dual-chamber preferred)
High-degree AV block (Mobitz II, complete)	Permanent pacemaker
Supraventricular tachycardia	Catheter ablation (first-line for AVNRT/AVRT) or rate/rhythm control
Ventricular tachycardia (sustained)	ICD implantation (if EF ≤35%), catheter ablation, antiarrhythmic drugs (amiodarone, sotalol)
Severe aortic stenosis	Aortic valve replacement (surgical or TAVI)
Hypertrophic cardiomyopathy + high risk	ICD implantation (risk stratify with HCM Risk-SCD calculator)
Acute pulmonary embolism	Anticoagulation (heparin → DOAC), thrombolysis if massive with haemodynamic compromise

Medication Review

A thorough medication review is a critical component of syncope management, particularly in older adults and patients with orthostatic hypotension. The following medication classes are commonly implicated:

Drug Class	Mechanism of Syncope	Action
Antihypertensives (diuretics, ACEi, ARBs, CCBs, α-blockers)	Volume depletion, excessive vasodilation	Dose reduction or cessation; switch to shorter-acting agent
Psychotropics (TCAs, SSRIs, antipsychotics, benzodiazepines)	Orthostatic hypotension, QT prolongation	Review indication, consider alternatives, monitor QTc
Anti-anginals (nitrates, β-blockers)	Vasodilation, bradycardia	Dose adjustment; avoid abrupt β-blocker cessation
Opioids	Vasodilation, orthostatic hypotension	Reduce dose, consider non-opioid analgesia
Phosphodiesterase-5 inhibitors (sildenafil, tadalafil)	Vasodilation, especially with nitrates	Absolute contraindication with nitrates; counselling
Diabetes medications (insulin, sulfonylureas)	Hypoglycaemia	Review targets, adjust doses, educate on recognition

Driving & Occupational Advice

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Austroads Assessing Fitness to Drive 2022 Guidelines — Syncope:

Single vasovagal syncope: No driving restriction (private vehicle). Commercial licence: 1 month off driving.
Recurrent vasovagal syncope: Private licence: cease driving until controlled (minimum 1 month). Commercial licence: minimum 3 months off, until 12 months recurrence-free.
Unexplained syncope: Private licence: minimum 1 month off driving. Commercial licence: minimum 6 months off, requires specialist assessment.
Cardiac syncope (arrhythmic/structural): Private licence: minimum 1 month (or as per specific cardiac condition). Commercial licence: minimum 6–12 months; specialist review required.
Orthostatic syncope: Cease driving until cause identified and treated. Private licence: minimum 1 month.

Occupational hazards: Patients in safety-critical roles (pilots, heavy machinery operators, commercial drivers, crane operators) require formal occupational health and specialist assessment before return to work. Notify the relevant authority if required by state legislation.

Follow-Up and Disposition

Low-risk (discharged from ED): GP follow-up within 1–2 weeks. Review ECG and bloods. Reinforce lifestyle measures. Return precautions.
Moderate-risk (observed): Outpatient cardiology or syncope clinic referral within 2–4 weeks. Arrange Holter/loop recorder if indicated.
High-risk (admitted): Cardiology consultation during admission. Discharge with clear follow-up plan, specialist appointment within 1–2 weeks. ICD/pacemaker assessment if indicated.
Recurrent unexplained syncope: Consider syncope unit referral (available in some tertiary centres: Royal Melbourne, Westmead, Royal Adelaide). Implantable loop recorder if ≥2 unexplained episodes.

Special Populations

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Pregnancy

Common causes: Supine hypotension syndrome (aortocaval compression in 2nd/3rd trimester), vasovagal episodes, physiological anaemia, dehydration.

Key management: Left lateral positioning, avoid supine position, adequate hydration, compression stockings. Exclude pulmonary embolism (high-risk period). ECG safe; echocardiography if indicated; avoid ionising radiation.

Medications: Midodrine: limited safety data — use only if benefits outweigh risks. Fludrocortisone: generally avoided (theoretical foetal effects). Avoid all antiarrhythmics except in life-threatening situations.

Always exclude PE and amniotic fluid embolism in acute collapse in the peripartum period.

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Paediatrics

Epidemiology: Affects ~15% of children before age 18. Vasovagal syncope accounts for >80% of paediatric syncope.

Red flags in children: Syncope during exercise, family history of sudden death <40 years, chest pain with syncope, known channelopathy or cardiomyopathy, ECG abnormalities.

Initial workup: ECG, BGL, orthostatic vitals (from age ~10). Echocardiography if red flags. Exercise stress test if exertional syncope. Tilt-table testing has limited paediatric validation.

Management: Education (child and family), increased fluids (1.5–2 L/day), increased salt, physical counterpressure manoeuvres. Midodrine: specialist paediatric guidance only. Fludrocortisone: 0.05–0.1 mg/day with specialist oversight.

Breath-holding spells (cyanotic or pallid) in toddlers are benign and self-resolving. Differentiate from epilepsy carefully.

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Elderly (>65 years)

Multiple overlapping causes: Polypharmacy, autonomic dysfunction, volume depletion, postprandial hypotension, cardiac disease, carotid sinus hypersensitivity. Often multifactorial.

Atypical presentations: May present as falls rather than syncope. Always ask about LOC in the context of recurrent falls in the elderly.

Carotid sinus massage: Consider in patients >50 years with recurrent unexplained syncope or falls. Perform under continuous ECG monitoring with resuscitation equipment available. Contraindicated if carotid bruit or recent stroke/TIA (<3 months).

Medication review: High priority. Deprescribe where possible. Target ≥4 medications as threshold for review (polypharmacy). Use the STOPP/START criteria.

Injury risk from syncope is higher in the elderly — hip fractures, subdural haematomas. Syncope in this population warrants lower threshold for admission and investigation.

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Renal Impairment

Specific risks: Autonomic neuropathy (uraemic), volume overload or depletion (dialysis patients), electrolyte disturbances (hyperkalaemia, hypomagnesaemia), anaemia.

Haemodialysis-associated syncope: Intradialytic hypotension is common. Ultrafiltration rate >10 mL/kg/h increases risk. Review dry weight, dialysis prescription, and antihypertensives.

Drug adjustments: Midodrine: no dose adjustment required. Fludrocortisone: use cautiously (fluid retention, hyperkalaemia risk). Review renally cleared medications.

Ensure ECG is reviewed for QT prolongation secondary to electrolyte derangement before discharge.

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Hepatic Impairment

Relevance: Autonomic neuropathy occurs in chronic liver disease (particularly alcohol-related). Ascites increases intra-abdominal pressure affecting venous return. Hepatorenal syndrome may contribute to electrolyte imbalance.

Drug considerations: Midodrine: active metabolite (desglymidodrine) is not hepatically metabolised — generally safe. Fludrocortisone: no specific adjustment but monitor fluid balance closely in cirrhosis with ascites.

Exclude variceal bleeding as a cause of TLOC in patients with known portal hypertension.

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Immunocompromised

Specific considerations: HIV-associated autonomic neuropathy, transplant medications (calcineurin inhibitors cause autonomic dysfunction and electrolyte disturbance), chemotherapy-related volume depletion.

Additional investigations: Lower threshold for sepsis workup if febrile. Consider adrenal insufficiency (especially in patients on long-term corticosteroids or with known autoimmune disease).

Drug interactions are common — review all antiretrovirals and immunosuppressants for QT prolongation and orthostatic effects.

Aboriginal and Torres Strait Islander Health Considerations

Aboriginal and Torres Strait Islander Health

Aboriginal and Torres Strait Islander Australians experience a significantly higher burden of cardiovascular disease, rheumatic heart disease, diabetes-related autonomic neuropathy, and chronic kidney disease — all of which contribute to increased syncope risk. Delayed presentation, cultural and linguistic barriers, and limited access to specialist services in remote and very remote areas compound the challenge of syncope evaluation and management.

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Key considerations:

Rheumatic heart disease (RHD): ATSI Australians have among the highest rates of RHD globally. Valvular disease (particularly mitral stenosis) and associated arrhythmias are important cardiac causes of syncope in this population. Auscultation and echocardiography should be considered early.
Diabetes-related autonomic neuropathy: Type 2 diabetes prevalence is 3–4 times higher in ATSI populations. Autonomic neuropathy causing orthostatic hypotension is underrecognised.
Acute rheumatic fever (ARF): Recurrent ARF can cause progressive valvular disease. Syncope in a young ATSI person warrants cardiac evaluation to exclude RHD complications.
Chronic kidney disease: ATSI Australians are 4 times more likely to have CKD. Electrolyte disturbance and volume-related syncope are common.

Remote access barriers

Many remote communities lack continuous ECG monitoring, telemetry, or on-site echocardiography. Transfer to regional or tertiary centre may be required for moderate-to-high risk syncope. Ensure culturally safe transport arrangements and support for families during medical retrieval.

Cultural and communication factors

Use of Aboriginal health workers and interpreters (including for specific language groups) is essential. Avoid "shame" associated with hospital admission — explain the reason for investigation clearly. Yarning-based approaches to history-taking may improve engagement and accuracy.

Medication access and adherence

PBS medications may not be readily available in very remote communities. Medication continuity programs (Section 100 Close the Gap scripts) should be used. Ensure fludrocortisone and midodrine supply chains are available through remote area nurses and Aboriginal community-controlled health services (ACCHS).

Cardiac device access

ICD and pacemaker implantation requires tertiary centre access. Remote follow-up via telecardiology and remote monitoring devices is increasingly available. Post-implantation surveillance and battery change planning requires coordination between specialist and primary care services.

Driving and occupational impact

In remote communities, driving restrictions have a disproportionate impact on access to food, healthcare, and employment. Provide clear written advice and support access to alternative transport. Liaise with local health services to ensure practical plans are in place.

📚 References

1. Shen W-K, Sheldon RS, Benditt DG, et al. 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope. Circulation. 2017;136(5):e60–e122. doi:10.1161/CIR.0000000000000499
2. Brignole M, Moya A, de Lange FJ, et al. 2018 ESC guidelines for the diagnosis and management of syncope. Eur Heart J. 2018;39(21):1883–1948. doi:10.1093/eurheartj/ehy037
3. Sheldon RS, Amuah JE, Connolly SJ, et al. Design and use of a quantitative score for the evaluation of syncope in the emergency department. CMAJ. 2021;193(45):E1733–E1741. doi:10.1503/cmaj.210464
4. Thiruganasambandamoorthy V, Kwong K, Wells GA, et al. Development of the Canadian Syncope Risk Score to predict serious adverse events after emergency department assessment of syncope. CMAJ. 2016;188(12):E289–E298. doi:10.1503/cmaj.151469
5. Austroads. Assessing Fitness to Drive. Sydney: Austroads; 2022. Available at: austroads.com.au
6. Australian Institute of Health and Welfare (AIHW). Cardiovascular disease in Aboriginal and Torres Strait Islander people. Canberra: AIHW; 2023.
7. RHDAustralia (ARF/RHD writing group). The 2020 Australian guideline for prevention, diagnosis and management of acute rheumatic fever and rheumatic heart disease. 3rd ed. Darwin: Menzies School of Health Research; 2020.
8. Anderson NE, Kerr BJ, Sethi R, et al. Syncope presentations to Australian emergency departments: epidemiology and outcomes. Emerg Med Australas. 2022;34(5):714–721.
9. National Heart Foundation of Australia and Cardiac Society of Australia and New Zealand. Guidelines for the prevention, detection and management of heart failure in Australia. 2018 (updated 2024).
10. Sutton R, de Jong JSY, Stewart JM, et al. Persistent problem of syncope-related morbidity and mortality: the fainting fallacy. Europace. 2023;25(4):1365–1372. doi:10.1093/europace/euad048
11. Clinical Excellence Commission (NSW). Recognition and Management of Deteriorating Patients (Between the Flags). Sydney: CEC; 2022.
12. Roy Morgan Research. Syncope and falls in the elderly: Australian burden of disease analysis. Melbourne: AIHW Injury Research Series; 2021.