Syncope Evaluation¶

DIAGNOSIS: Syncope and Collapse ICD-10: R55 (Syncope and collapse) ADDITIONAL ICD-10: T67.1 (Heat syncope), I95.1 (Orthostatic hypotension), G90.0 (Idiopathic peripheral autonomic neuropathy), G90.3 (Multi-system degeneration of ANS), R00.1 (Bradycardia), I49.9 (Cardiac arrhythmia, unspecified), F48.8 (Psychogenic syncope) CLINICAL SYNONYMS: Fainting, passing out, blackout, loss of consciousness, LOC, vasovagal episode, neurocardiogenic syncope, vasodepressor syncope, reflex syncope SCOPE: Comprehensive evaluation of transient loss of consciousness (TLOC) due to cerebral hypoperfusion. Covers vasovagal/reflex syncope, orthostatic hypotension, cardiac arrhythmias, and neurologic mimics. Includes risk stratification, diagnostic workup, and management. Excludes seizure-related loss of consciousness (see Seizure plan), stroke, and metabolic causes of altered mental status.

STATUS: Draft - Pending Review

PRIORITY KEY: STAT = Immediate | URGENT = Within hours | ROUTINE = Standard | EXT = Extended/atypical cases | - = Not applicable to this setting

SECTION A: ACTION ITEMS¶

1. LABORATORY WORKUP¶

1A. Essential/Core Labs¶

Test	Rationale	Target Finding	ED	HOSP	OPD	ICU
ECG (12-lead)	Rule out arrhythmia, conduction abnormality, ischemia, cardiomyopathy (prolonged QT, Brugada, WPW, ARVC)	Normal sinus rhythm; QTc <450 ms (M), <460 ms (F); no preexcitation or Brugada pattern	STAT	STAT	ROUTINE	STAT
Glucose (fingerstick or serum)	Rule out hypoglycemia as cause of altered consciousness	Normal (70-100 mg/dL)	STAT	STAT	ROUTINE	STAT
CBC	Evaluate for anemia causing reduced oxygen delivery; infection	Hgb >12 g/dL; no leukocytosis	STAT	STAT	ROUTINE	STAT
BMP	Electrolyte abnormalities can cause arrhythmias or contribute to syncope	Normal Na, K, Mg, Ca, glucose, creatinine	STAT	STAT	ROUTINE	STAT
Troponin	Cardiac ischemia as cause of syncope; elevated in PE, aortic dissection	Negative (<0.04 ng/mL or institution-specific)	STAT	STAT	-	STAT
Orthostatic vital signs	Diagnose orthostatic hypotension (BP drop >20/10 mmHg or HR increase >30 bpm)	No significant change; BP stable within 3 min of standing	STAT	STAT	ROUTINE	-

1B. Extended Workup (Second-line)¶

Test	Rationale	Target Finding	ED	HOSP	OPD	ICU
BNP or NT-proBNP	Screen for heart failure; elevated in cardiac syncope	BNP <100 pg/mL; NT-proBNP <300 pg/mL	URGENT	URGENT	ROUTINE	URGENT
D-dimer	Pulmonary embolism suspected (consider Wells score)	<500 ng/mL (age-adjusted: age x 10 if >50 yo)	URGENT	URGENT	-	URGENT
TSH	Thyroid dysfunction contributing to arrhythmias or autonomic dysfunction	Normal (0.4-4.0 mIU/L)	-	ROUTINE	ROUTINE	-
Magnesium	Hypomagnesemia can precipitate arrhythmias	Normal (1.7-2.2 mg/dL)	URGENT	ROUTINE	ROUTINE	URGENT
Lactic acid	Tissue hypoperfusion; consider if prolonged LOC or concern for cardiogenic shock	Normal (<2.0 mmol/L)	URGENT	URGENT	-	URGENT
Pregnancy test (urine or serum)	Ectopic pregnancy can present with syncope; all reproductive-age women	Negative (unless known pregnancy)	STAT	STAT	ROUTINE	STAT

1C. Rare/Specialized (Refractory or Atypical)¶

Test	Rationale	Target Finding	ED	HOSP	OPD	ICU
Plasma catecholamines (supine and standing)	Autonomic failure workup; pure autonomic failure vs MSA	Normal increase with standing; absence suggests autonomic failure	-	EXT	EXT	-
Cortisol (AM)	Adrenal insufficiency causing orthostatic hypotension	>10 mcg/dL (AM); consider ACTH stim test if borderline	-	EXT	EXT	-
Prolactin (within 20 min of event)	Distinguish seizure from syncope; elevated post-ictally	Normal (<20 ng/mL); >2x baseline suggests seizure	STAT	STAT	-	-
HbA1c	Screen for diabetes contributing to autonomic neuropathy	<5.7% (normal); diabetic autonomic neuropathy if elevated with symptoms	-	ROUTINE	ROUTINE	-
Genetic testing (SCN5A, KCNQ1, KCNH2)	Long QT syndrome, Brugada syndrome suspected	No pathogenic variant	-	-	EXT	-
Autoimmune panel (ganglionic AChR Ab, GAD65)	Autoimmune autonomic ganglionopathy suspected	Negative	-	EXT	EXT	-

2. DIAGNOSTIC IMAGING & STUDIES¶

2A. Essential/First-line¶

Study	Timing	Target Finding	Contraindications	ED	HOSP	OPD	ICU
Continuous cardiac monitoring (telemetry)	Ongoing in ED/hospital	No arrhythmia detected	None	STAT	STAT	-	STAT
Echocardiogram (TTE)	If structural heart disease suspected, abnormal ECG, cardiac murmur, or high-risk features	Normal LV function (EF >50%); no structural abnormality	None	URGENT	URGENT	ROUTINE	URGENT
CT Head non-contrast	Head trauma from fall; focal neurological deficits; concern for SAH	No hemorrhage, mass, or acute abnormality	Pregnancy (relative)	STAT	URGENT	-	STAT
Chest X-ray	Cardiac silhouette, pulmonary edema, widened mediastinum (dissection)	Normal heart size; clear lungs	None	URGENT	ROUTINE	-	URGENT

2B. Extended¶

Study	Timing	Target Finding	Contraindications	ED	HOSP	OPD	ICU
CTA Chest	Pulmonary embolism suspected (high Wells score, elevated D-dimer)	No PE; patent pulmonary arteries	Contrast allergy, CKD (eGFR <30)	STAT	STAT	-	STAT
Holter monitor (24-48 hour)	Recurrent syncope; arrhythmia suspected but not captured	No significant arrhythmia; correlate with symptoms	None	-	ROUTINE	ROUTINE	-
Event recorder (30 days)	Infrequent syncope (monthly); need longer monitoring	Symptom-rhythm correlation	None	-	-	ROUTINE	-
Insertable loop recorder (ILR)	Recurrent unexplained syncope despite workup; infrequent events	Diagnose arrhythmia at time of syncope	None (minor procedure)	-	-	ROUTINE	-
Tilt table testing	Suspected vasovagal syncope with unclear diagnosis; recurrent syncope affecting QOL	Positive (reproduces symptoms with hypotension/bradycardia); or negative excluding reflex syncope	Recent MI, severe aortic stenosis, severe CAD	-	EXT	ROUTINE	-
Carotid ultrasound	Syncope with head rotation; carotid bruit	No significant stenosis (>70%); no hypersensitivity	None	-	ROUTINE	ROUTINE	-
Stress testing (exercise or pharmacologic)	Exertional syncope; ischemia suspected	No ischemia; normal BP response	Unstable angina, uncontrolled arrhythmia	-	URGENT	ROUTINE	-

2C. Rare/Specialized¶

Study	Timing	Target Finding	Contraindications	ED	HOSP	OPD	ICU
EEG (routine or ambulatory)	Seizure vs syncope uncertain; convulsive movements reported; prolonged confusion	Normal; no epileptiform discharges	None	-	ROUTINE	ROUTINE	-
MRI Brain	Neurological symptoms; focal deficits; posterior circulation insufficiency suspected	Normal; no structural abnormality	MRI-incompatible devices, severe claustrophobia	-	URGENT	ROUTINE	-
Autonomic function testing (QSART, HRV, Valsalva)	Orthostatic hypotension; suspected autonomic neuropathy or failure	Normal autonomic responses	Recent MI, uncontrolled HTN	-	-	EXT	-
Electrophysiology study (EPS)	High-risk structural heart disease; non-diagnostic workup; suspected Brugada	No inducible arrhythmia	Anticoagulation issues, active infection	-	-	EXT	-
Carotid sinus massage	Syncope with head turning or tight collars; age >40; after ruling out carotid stenosis	No pause >3 sec; no BP drop >50 mmHg	Carotid bruit, recent stroke/TIA, carotid stenosis	-	ROUTINE	ROUTINE	-
Cardiac MRI	Arrhythmogenic cardiomyopathy (ARVC) suspected; infiltrative disease	No fibrosis, fat infiltration, or structural abnormality	MRI contraindications; CKD for gadolinium	-	-	EXT	-
Exercise tilt test	Exercise-induced syncope with negative standard testing	No abnormal response	Same as tilt table and exercise testing	-	-	EXT	-

3. TREATMENT¶

3A. Acute/Emergent¶

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
IV Normal Saline	IV	Volume depletion; orthostatic hypotension; vagal syncope recovery	500 mL IV bolus; 1000 mL IV bolus; 125 mL/hr IV :: IV :: :: 500-1000 mL bolus for acute syncope; maintenance if dehydrated	Heart failure; volume overload	Intake/output; signs of overload; reassess orthostatics	STAT	STAT	-	STAT
Atropine	IV	Symptomatic bradycardia causing syncope	0.5 mg IV push; 1 mg IV push :: IV :: :: 0.5-1 mg IV push; may repeat q3-5min; max 3 mg total	Tachyarrhythmia; glaucoma	HR, BP, rhythm	STAT	STAT	-	STAT
Transcutaneous pacing	External	Symptomatic bradycardia unresponsive to atropine	60-80 mA; adjust for capture :: External :: :: Start 60 mA, increase until capture; rate 60-80 bpm	Pacemaker in place (relative); conscious patient (sedate first)	Capture confirmation; BP; sedation level	STAT	STAT	-	STAT
Trendelenburg position	Physical	Immediate management of acute syncope	Supine with legs elevated :: Physical :: :: Elevate legs 30-45 degrees; maintain until fully recovered	Respiratory distress; increased ICP	Mental status; BP recovery	STAT	STAT	-	STAT
Epinephrine	IV/IM	Anaphylaxis causing syncope	0.3 mg IM; 0.5 mg IM; 0.1 mg IV :: IM/IV :: :: 0.3-0.5 mg IM (1:1000); 0.1 mg IV (1:10,000) for severe	Uncontrolled hypertension (relative in anaphylaxis)	HR, BP, symptoms	STAT	STAT	-	STAT
Glucagon	IV/IM	Beta-blocker or calcium channel blocker toxicity causing bradycardia/hypotension	3-5 mg IV; 10 mg IV :: IV :: :: 3-10 mg IV bolus; may follow with infusion 1-5 mg/hr	Pheochromocytoma; insulinoma	Glucose, BP, HR, nausea	STAT	STAT	-	STAT

3B. Symptomatic Treatments¶

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Compression stockings (30-40 mmHg)	Physical	Orthostatic hypotension; vasovagal syncope prophylaxis	Waist-high preferred :: Physical :: :: 30-40 mmHg compression; waist-high more effective than knee-high; wear during daytime	Peripheral vascular disease; skin ulcers	Skin integrity; compliance; symptom frequency	-	ROUTINE	ROUTINE	-
Increased salt intake	Dietary	Orthostatic hypotension; recurrent vasovagal syncope (no contraindication)	6-10 g Na/day :: Dietary :: :: Increase to 6-10 g sodium daily (salt tablets 1 g TID or dietary salt)	Heart failure; uncontrolled HTN; CKD	BP; weight; edema; syncope frequency	-	ROUTINE	ROUTINE	-
Increased fluid intake	Dietary	Orthostatic hypotension; volume depletion	2-3 L/day :: Dietary :: :: 2-3 L daily fluid intake; bolus 500 mL water prior to prolonged standing	Heart failure; fluid restriction needed	Volume status; electrolytes	URGENT	ROUTINE	ROUTINE	-
Physical counterpressure maneuvers	Physical	Prodromal symptoms of vasovagal syncope	Perform at onset of prodrome :: Physical :: :: Leg crossing with tensing; handgrip; arm tensing; squat; abort 30% of episodes	None	Symptom diary; effectiveness	URGENT	ROUTINE	ROUTINE	-
Head-of-bed elevation	Physical	Orthostatic hypotension; supine hypertension	10-20 degree elevation :: Physical :: :: Elevate head of bed 10-20 degrees (4-6 inch blocks); reduces nocturnal natriuresis	None	Morning BP; symptom frequency	-	ROUTINE	ROUTINE	-

3C. Second-line/Refractory¶

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Midodrine	PO	Orthostatic hypotension refractory to non-pharmacologic measures	2.5 mg TID; 5 mg TID; 10 mg TID :: PO :: :: Start 2.5-5 mg TID (q4h while upright); titrate to 10 mg TID; last dose 4 hrs before bed	Supine HTN; urinary retention; severe heart disease; pheochromocytoma	Supine BP (avoid >180/100); urinary symptoms	-	ROUTINE	ROUTINE	-
Fludrocortisone	PO	Orthostatic hypotension; volume expansion needed	0.1 mg daily; 0.2 mg daily :: PO :: :: Start 0.1 mg daily; may increase to 0.2-0.3 mg daily; takes 1-2 weeks for effect	Heart failure; uncontrolled HTN; hypokalemia	K+; supine BP; weight; edema	-	ROUTINE	ROUTINE	-
Droxidopa (Northera)	PO	Neurogenic orthostatic hypotension (autonomic failure, Parkinson's)	100 mg TID; 200 mg TID; 300 mg TID; 600 mg TID :: PO :: :: Start 100 mg TID; titrate by 100 mg TID q24-48h; max 600 mg TID	Supine HTN; concomitant catecholamine drugs	Supine BP; syncope frequency	-	-	ROUTINE	-
Pyridostigmine	PO	Orthostatic hypotension with intact post-ganglionic neurons	30 mg TID; 60 mg TID :: PO :: :: 30-60 mg PO TID; enhances ganglionic transmission	Bowel/bladder obstruction; bradycardia	GI side effects; HR	-	-	ROUTINE	-
Atomoxetine	PO	Neurogenic orthostatic hypotension (off-label)	10 mg daily; 18 mg BID :: PO :: :: 10-18 mg BID; norepinephrine reuptake inhibitor	MAOIs; narrow-angle glaucoma; pheochromocytoma	BP; HR; urinary retention	-	-	EXT	-
Beta-blocker (low-dose)	PO	Vasovagal syncope with prominent cardioinhibitory component (controversial)	Metoprolol 25 mg BID; Atenolol 25 mg daily :: PO :: :: Low-dose beta-blocker (metoprolol 25 mg BID or atenolol 25 mg daily); limited evidence	Bradycardia; hypotension; asthma; 2nd/3rd degree AVB	HR; BP; syncope frequency	-	-	EXT	-
SSRI (paroxetine, sertraline)	PO	Recurrent vasovagal syncope refractory to first-line measures	Paroxetine 20 mg daily; Sertraline 50 mg daily :: PO :: :: Paroxetine 20 mg daily or sertraline 50 mg daily; may modulate autonomic response	MAOIs; uncontrolled bipolar	Mood; syncope frequency	-	-	EXT	-

3D. Disease-Modifying or Chronic Therapies¶

Treatment	Route	Indication	Dosing	Pre-Treatment Requirements	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Permanent pacemaker	Implant	Cardioinhibitory syncope with documented asystole >3 sec or symptomatic bradycardia	Dual-chamber preferred :: Implant :: :: Dual-chamber pacemaker (DDD) for sinus node dysfunction; VVI/DDD for AV block	EPS, Holter showing bradyarrhythmia, tilt-positive cardioinhibitory	Active infection; coagulopathy	Device interrogation q6-12mo; wound healing	-	-	ROUTINE	-
Implantable cardioverter-defibrillator (ICD)	Implant	Syncope with structural heart disease and high sudden death risk	Per device type :: Implant :: :: Single or dual chamber ICD based on indication	EF assessment, risk stratification completed	Active infection; terminal illness	Device interrogation; driving restrictions	-	-	ROUTINE	-
Catheter ablation	Procedure	Documented arrhythmia causing syncope (SVT, VT, WPW)	Ablation of arrhythmia focus :: Procedure :: :: EP study with ablation of identified arrhythmia substrate	EP study identifying arrhythmia	Active infection; coagulopathy	Post-procedure rhythm monitoring	-	-	ROUTINE	-
Cardioneuroablation	Procedure	Refractory cardioinhibitory syncope with documented asystole	Ablation of vagal ganglia :: Procedure :: :: Catheter-based ablation of cardiac vagal ganglia; emerging therapy	Failed conservative management	Limited availability; investigational	HR variability; syncope recurrence	-	-	EXT	-

4. OTHER RECOMMENDATIONS¶

4A. Referrals & Consults¶

Recommendation	ED	HOSP	OPD	ICU
Cardiology consultation for arrhythmia evaluation, structural heart disease assessment, or device implantation consideration	URGENT	URGENT	ROUTINE	URGENT
Electrophysiology referral for documented arrhythmias requiring ablation, pacemaker or ICD evaluation, or unexplained high-risk syncope	-	ROUTINE	ROUTINE	-
Neurology consultation if seizure-syncope differentiation unclear, autonomic testing needed, or neurological symptoms present	URGENT	ROUTINE	ROUTINE	-
Autonomic disorders specialist for recurrent orthostatic hypotension, suspected pure autonomic failure, or multiple system atrophy	-	-	ROUTINE	-
Driving evaluation per state regulations for commercial drivers or recurrent unexplained syncope affecting driving ability	-	-	ROUTINE	-
Psychiatry referral if psychogenic pseudosyncope suspected based on atypical features and normal workup	-	ROUTINE	ROUTINE	-
Fall prevention physical therapy for elderly patients with recurrent syncope to reduce injury risk	-	ROUTINE	ROUTINE	-
Occupational health evaluation for patients in safety-sensitive occupations (pilots, heavy machinery operators, commercial drivers)	-	-	ROUTINE	-

4B. Patient Instructions¶

Recommendation	ED	HOSP	OPD
Return immediately if syncope recurs, especially with chest pain, palpitations, shortness of breath, or exercise (may indicate cardiac cause requiring urgent evaluation)	STAT	-	ROUTINE
Return immediately if prolonged confusion, seizure activity, tongue biting, or urinary incontinence occurs with loss of consciousness (suggests seizure rather than syncope)	STAT	-	ROUTINE
Do NOT drive until cleared by physician due to risk of syncope while operating a vehicle; specific restrictions depend on diagnosis and state law	URGENT	ROUTINE	ROUTINE
Avoid prolonged standing, hot environments, and dehydration which are common triggers for vasovagal syncope	URGENT	ROUTINE	ROUTINE
Learn to recognize prodromal symptoms (lightheadedness, warmth, nausea, tunnel vision) and immediately sit or lie down to prevent injury	URGENT	ROUTINE	ROUTINE
Perform physical counterpressure maneuvers (leg crossing, squatting, handgrip) at first sign of prodrome to abort vasovagal episode	URGENT	ROUTINE	ROUTINE
Rise slowly from lying to sitting to standing (staged position changes) to prevent orthostatic syncope	URGENT	ROUTINE	ROUTINE
Maintain adequate hydration (2-3 L daily) and salt intake (unless contraindicated) to support blood volume	ROUTINE	ROUTINE	ROUTINE
Keep a symptom diary noting triggers, prodrome, circumstances, duration of LOC, and recovery to aid diagnosis	-	ROUTINE	ROUTINE
Wear medical alert identification if recurrent syncope diagnosis confirmed	-	-	ROUTINE

4C. Lifestyle & Prevention¶

Recommendation	ED	HOSP	OPD
Avoid known triggers including prolonged standing, crowded/hot environments, excessive alcohol, and large meals	URGENT	ROUTINE	ROUTINE
Increase oral fluid intake to 2-3 liters daily to maintain intravascular volume and reduce syncope frequency	URGENT	ROUTINE	ROUTINE
Increase dietary salt intake to 6-10 g/day if no contraindication (hypertension, heart failure, CKD) to expand plasma volume	-	ROUTINE	ROUTINE
Wear waist-high compression stockings (30-40 mmHg) during daytime to reduce venous pooling	-	ROUTINE	ROUTINE
Avoid sudden postural changes; use staged position changes (lie-sit-stand with 1-2 min at each stage)	URGENT	ROUTINE	ROUTINE
Review and minimize medications that contribute to hypotension (diuretics, antihypertensives, alpha-blockers, nitrates, psychiatric medications)	URGENT	ROUTINE	ROUTINE
Avoid excessive heat exposure including hot showers, saunas, and hot tubs which cause vasodilation	-	ROUTINE	ROUTINE
Sleep with head of bed elevated 10-20 degrees to reduce nocturnal natriuresis and improve morning orthostatic tolerance	-	ROUTINE	ROUTINE
Moderate regular aerobic exercise to improve vascular tone and reduce vasovagal susceptibility; avoid deconditioning	-	ROUTINE	ROUTINE
Alcohol moderation or avoidance as alcohol causes vasodilation and impairs autonomic reflexes	-	ROUTINE	ROUTINE

SECTION B: REFERENCE¶

5. DIFFERENTIAL DIAGNOSIS¶

Alternative Diagnosis	Key Distinguishing Features	Tests to Differentiate
Vasovagal (neurocardiogenic) syncope	Prodrome (warmth, nausea, diaphoresis, tunnel vision); identifiable trigger (prolonged standing, pain, emotional stress); rapid recovery	History; tilt table testing reproduces symptoms
Orthostatic hypotension	Syncope immediately upon standing; BP drop >20/10 mmHg within 3 min of standing; associated with medications, volume depletion, or autonomic failure	Orthostatic vital signs; autonomic function testing
Cardiac arrhythmia (tachy or brady)	Sudden onset without prodrome; palpitations; associated with exertion or supine position; abnormal ECG	ECG; Holter; event recorder; EP study
Structural heart disease (AS, HCM, PE)	Exertional syncope; murmur; dyspnea; chest pain; signs of right heart failure (PE)	Echo; CT chest (PE); cardiac MRI
Situational syncope	Occurs with specific triggers: micturition, defecation, cough, swallow	History is diagnostic; occurs during or immediately after trigger activity
Carotid sinus hypersensitivity	Syncope with head turning, shaving, tight collars; age >40; male predominance	Carotid sinus massage (after excluding stenosis)
Seizure (convulsive syncope mimic)	Tonic-clonic movements; lateral tongue bite; prolonged confusion (>5 min); urinary incontinence; no prodrome	EEG; prolactin (within 20 min); witnessed description
Psychogenic pseudosyncope	Very frequent episodes; prolonged duration; eyes closed; no injury; normal exam during event	Normal testing during observed episode; psychiatric evaluation
Hypoglycemia	Associated with diabetes or insulin use; diaphoresis; hunger; confusion; responds to glucose	Fingerstick glucose; witnessed glucose administration
Vertebrobasilar insufficiency	Associated with head movement, vertigo, diplopia, dysarthria, drop attacks	MRA head/neck; vertebral Doppler
Subclavian steal syndrome	Arm exercise triggers; BP difference >20 mmHg between arms; vertebrobasilar symptoms	Bilateral arm BPs; subclavian Doppler; angiography
Pulmonary embolism	Dyspnea; pleuritic chest pain; unilateral leg swelling; tachycardia; hypoxia	D-dimer; CTA chest; Wells score
Aortic dissection	Tearing chest/back pain; BP difference between arms; widened mediastinum	CT angiography; TEE
Ruptured AAA	Abdominal or back pain; pulsatile mass; hypotension; older patient	CT abdomen; bedside ultrasound
Subarachnoid hemorrhage	Thunderclap headache; neck stiffness; altered mental status; may have syncope at onset	CT head; lumbar puncture if CT negative

6. MONITORING PARAMETERS¶

Parameter	Frequency	Target/Threshold	Action if Abnormal	ED	HOSP	OPD	ICU
Continuous cardiac telemetry	Continuous while admitted	No significant arrhythmia	Capture rhythm strips; cardiology consult for significant arrhythmia	STAT	STAT	-	STAT
Orthostatic vital signs	Q8H in hospital; each clinic visit	BP drop <20/10 mmHg; HR increase <30 bpm	Optimize volume; review medications; consider pharmacotherapy	STAT	ROUTINE	ROUTINE	-
Syncope recurrence	Each encounter	No recurrence	Reassess diagnosis; consider advanced testing (ILR)	STAT	ROUTINE	ROUTINE	-
ECG intervals (QTc, PR, QRS)	Baseline; with QT-prolonging drugs	QTc <500 ms; PR <300 ms; QRS <120 ms	Discontinue offending drugs; cardiology evaluation	STAT	ROUTINE	ROUTINE	STAT
Fall risk assessment	Each encounter	Low risk	PT evaluation; home safety assessment; assistive devices	URGENT	ROUTINE	ROUTINE	-
Injury from falls	Each encounter	No injury	Head imaging if concern for intracranial injury	STAT	ROUTINE	ROUTINE	STAT
Medication reconciliation	Each encounter	No offending medications	Reduce/discontinue hypotensive medications	URGENT	ROUTINE	ROUTINE	-
Driving status	Each visit	Cleared per guidelines	Document restrictions; report to DMV if required	-	ROUTINE	ROUTINE	-
Response to treatment (midodrine, fludrocortisone)	2-4 weeks after initiation	Improved orthostatic tolerance; reduced syncope	Dose adjustment; alternative therapy	-	-	ROUTINE	-

7. DISPOSITION CRITERIA¶

Disposition	Criteria
Discharge home	Low-risk features: isolated vasovagal syncope with clear trigger, normal ECG, normal cardiac exam, no significant injury, reliable follow-up; San Francisco Syncope Rule negative OR Canadian Syncope Risk Score very low/low risk
Observation (ED or short stay)	Intermediate risk: unexplained syncope with normal initial workup; awaiting troponin results; awaiting echocardiogram; single syncopal episode without high-risk features
Admit to floor	High-risk features: abnormal ECG, structural heart disease, heart failure, exertional syncope, syncope causing significant injury, recurrent syncope of unclear etiology, syncope with chest pain or dyspnea
Admit to ICU/monitored bed	Very high-risk: hemodynamic instability, documented malignant arrhythmia, syncope with ongoing ischemia, severe bradycardia requiring pacing, PE with hypotension
Outpatient follow-up	Low-risk syncope discharged from ED: cardiology/neurology follow-up within 1-2 weeks; recurrent vasovagal syncope: 2-4 weeks; post-device implantation: per device protocol

8. EVIDENCE & REFERENCES¶

Recommendation	Evidence Level	Source
Canadian Syncope Risk Score for ED risk stratification	Class I, Level B	Thiruganasambandamoorthy et al. CMAJ 2016
San Francisco Syncope Rule validation	Class II, Level B	Quinn et al. Ann Emerg Med 2004
Tilt table testing for vasovagal syncope diagnosis	Class IIa, Level B	Sheldon et al. Circulation 2015
Physical counterpressure maneuvers reduce syncope recurrence	Class I, Level B	van Dijk et al. Circulation 2006
Midodrine for orthostatic hypotension	Class I, Level A	Izcovich et al. Heart 2014
Fludrocortisone for orthostatic hypotension	Class IIa, Level B	Sheldon et al. Circulation 2015
Droxidopa for neurogenic orthostatic hypotension	Class I, Level A	Kaufmann et al. Neurology 2014
Pacemaker for cardioinhibitory carotid sinus syndrome	Class I, Level B	Brignole et al. Eur Heart J 2018
ILR superior to conventional testing for unexplained syncope	Class I, Level A	Krahn et al. Circulation 2001
POST trial: beta-blockers ineffective for vasovagal syncope	Class I, Level A	Sheldon et al. Circulation 2006
ESC Guidelines on syncope diagnosis and management	Consensus	Brignole et al. Eur Heart J 2018
ACC/AHA/HRS Guidelines on bradycardia and pacing	Consensus	Kusumoto et al. Circulation 2019
Compression stockings reduce orthostatic intolerance	Class IIa, Level B	Figueroa et al. Neurology 2015
Autonomic testing in orthostatic hypotension	Class IIa, Level C	Freeman et al. Neurology 2011
Seizure vs syncope differentiation: prolactin levels	Class II, Level B	Chen et al. Neurology 2005
Driving restrictions after syncope	Consensus	Epstein et al. J Am Coll Cardiol 2007

CHANGE LOG¶

v1.0 (January 27, 2026) - Initial template creation - Comprehensive coverage of syncope evaluation including vasovagal, orthostatic, and cardiac etiologies - San Francisco Syncope Rule and Canadian Syncope Risk Score included in disposition criteria - Tilt table testing and autonomic function testing indications - EEG indications for seizure vs syncope differentiation - Driving restriction guidance - Structured dosing format for order sentence generation - PubMed-verified citations

APPENDIX A: Risk Stratification Tools¶

San Francisco Syncope Rule (SFSR)¶

Purpose: Identify patients at risk for serious outcomes within 30 days

High-risk features (any one = high risk): - C - Congestive heart failure history - H - Hematocrit <30% - E - ECG abnormality (non-sinus rhythm or new changes) - S - Shortness of breath - S - Systolic BP <90 mmHg at any time

Interpretation: - No criteria present = Low risk (~2% 7-day serious outcome) - Any criteria present = High risk (~15-25% serious outcome); consider admission

Sensitivity: 96-98% for serious outcomes

Canadian Syncope Risk Score (CSRS)¶

Purpose: More precise risk stratification than SFSR; validated for 30-day serious outcomes

Score Calculation:

Variable	Points
Predisposition to vasovagal symptoms	-1
Heart disease history or elevated BNP	+1
Any systolic BP reading <90 or >180 mmHg	+2
Troponin elevated (>99th percentile ULN)	+2
Abnormal QRS axis (<-30 or >100 degrees)	+1
QRS duration >130 ms	+1
QTc >480 ms	+2
ED diagnosis of cardiac syncope	+2
ED diagnosis of vasovagal syncope	-2

Risk Categories:

Score	Risk Category	30-day Serious Outcome
-3 to -2	Very Low	0.4%
-1 to 0	Low	1.2%
1 to 3	Medium	3.1%
4 to 5	High	9.5%
6 to 11	Very High	28.9%

Management Guidance: - Very Low/Low: Consider discharge with outpatient follow-up - Medium: Consider ED observation or short stay - High/Very High: Admission for monitoring and evaluation

Red Flags Requiring Urgent Evaluation¶

Category	Concerning Features
History	Exertional syncope; supine syncope; syncope without prodrome; palpitations immediately before event; family history of sudden death <50 yo
Cardiac	Known structural heart disease; heart failure; prior MI; aortic stenosis murmur; ICD shocks
ECG	Long QT (>480 ms); short QT (<340 ms); Brugada pattern; delta wave (WPW); epsilon wave (ARVC); AV block; wide QRS; new ischemia
Event	Significant injury requiring treatment; syncope while driving; recurrent episodes (>3/year)

APPENDIX B: Seizure vs Syncope Differentiation¶

Clinical Features Comparison¶

Feature	Syncope	Seizure
Trigger	Usually present (standing, pain, heat)	Usually absent (except photosensitive or reflex)
Prodrome	Common (lightheadedness, warmth, nausea, vision change)	Rare; may have aura (olfactory, gustatory, deja vu)
Duration of LOC	Brief (<30 seconds typically)	Variable (30 sec to minutes)
Movements during	May have brief myoclonic jerks (convulsive syncope)	Sustained tonic-clonic activity; rhythmic
Timing of movements	After falling (due to hypoperfusion)	From onset or within seconds
Eye position	Closed or rolling up	Open; deviated or staring
Tongue bite	Rare; tip if present	Lateral tongue laceration (highly specific)
Urinary incontinence	Occasionally	Common
Post-event confusion	Brief (<30 seconds)	Prolonged (minutes to hours)
Post-event fatigue	Mild	Profound; may sleep for hours
Pallor	Prominent before and during	Usually absent
Cyanosis	Absent (initially pale)	May be present
Memory of event	Recalls prodrome; brief LOC	Amnesia for ictus; may recall aura

Diagnostic Testing¶

Test	Findings Suggesting Seizure
Prolactin	>2x baseline if drawn within 20 minutes of event (sensitivity ~60%)
CK	Elevated 12-24 hours post-event if generalized tonic-clonic
EEG	Epileptiform discharges (spikes, sharp waves, spike-wave)
MRI Brain	Structural lesion; mesial temporal sclerosis; cortical dysplasia

Convulsive Syncope ("Fainting with Twitching")¶

Occurs in up to 10-15% of syncope episodes
Brief myoclonic jerks due to cerebral hypoperfusion
Typically <30 seconds, less rhythmic than seizure
Rapid recovery without prolonged confusion
Does NOT require anticonvulsant treatment

APPENDIX C: Driving Restrictions After Syncope¶

General Principles¶

Regulations vary by state/country
Distinction between private and commercial drivers
Must consider underlying etiology and treatment status

Private Drivers (Non-Commercial)¶

Diagnosis	Typical Restriction	Resume When
Vasovagal syncope (single episode)	Usually none	Prodrome present; avoidable trigger identified
Vasovagal syncope (recurrent)	Variable	3-12 months symptom-free; effective prevention
Unexplained syncope	6-12 months	Diagnosis established or 6-12 months event-free
Cardiac syncope (arrhythmia)	Until treated	Successful treatment (ablation, pacemaker, ICD); typically 1 week to 6 months
Cardiac syncope (structural)	Until treated	Surgical repair; stable on treatment
Orthostatic hypotension	Variable	Controlled on treatment; no syncope without prodrome

Commercial Drivers (CDL, Pilots, Heavy Equipment)¶

More stringent restrictions apply
Often require specialist clearance
May require symptom-free period of 1-5 years
Unexplained syncope often disqualifies from commercial driving
Must report to appropriate regulatory agency

Documentation Requirements¶

Document counseling about driving restrictions in medical record
Provide written instructions to patient
Some jurisdictions require mandatory reporting to DMV
Consider medical alert bracelet for frequent episodes

APPENDIX D: Tilt Table Testing Protocol¶

Indications¶

Recurrent unexplained syncope affecting quality of life
Single syncopal episode in high-risk setting (injury, driving, occupational hazard)
Confirm diagnosis of vasovagal syncope when history equivocal
Evaluate efficacy of treatment in recurrent reflex syncope
Differentiate delayed orthostatic hypotension from reflex syncope

Contraindications¶

Recent MI or unstable angina (<30 days)
Severe aortic stenosis
Severe proximal coronary artery disease
Severe mitral stenosis
Known severe cerebrovascular disease

Protocol (Italian Protocol Most Common)¶

Baseline: Patient supine for 5-20 minutes; establish baseline BP and HR
Passive phase: Tilt to 60-70 degrees for 20-45 minutes
Drug provocation (if passive phase negative):
Isoproterenol: 1-3 mcg/min IV while tilted
OR Nitroglycerin: 300-400 mcg sublingual while tilted
Positive response: Reproduce syncope with hypotension and/or bradycardia
Return to supine immediately upon positive response or symptoms

Response Types¶

Type	Hemodynamic Pattern
Type 1 (Mixed)	HR falls but not <40 bpm for >10 sec; BP falls before HR
Type 2A (Cardioinhibitory without asystole)	HR <40 bpm for >10 sec; asystole <3 sec
Type 2B (Cardioinhibitory with asystole)	Asystole >3 sec; BP drop follows or occurs with HR drop
Type 3 (Vasodepressor)	HR doesn't fall >10% from peak; BP falls causing syncope

Treatment Implications¶

Vasodepressor (Type 3): Lifestyle modifications; compression stockings; hydration/salt; consider midodrine
Cardioinhibitory with asystole (Type 2B): Consider pacemaker if recurrent and refractory
Mixed (Type 1): Lifestyle modifications first; pharmacotherapy rarely needed