Syncope Evaluation¶

VERSION: 1.0 CREATED: January 29, 2026 REVISED: January 29, 2026 STATUS: Approved

DIAGNOSIS: Syncope

ICD-10: R55 (Syncope and collapse), T67.1 (Heat syncope), G90.01 (Carotid sinus syncope), I95.1 (Orthostatic hypotension)

CPT CODES: 82962 (Fingerstick glucose), 85025 (CBC), 80048 (BMP), 84484 (Troponin), 83880 (BNP or NT-proBNP), 84443 (TSH), 82533 (Cortisol), 85379 (D-dimer), 87040 (Blood cultures), 93000 (12-lead ECG), 93306 (Transthoracic echocardiogram), 93224 (Holter monitor), 93268 (Event recorder), 95924 (Tilt table test), 70450 (CT head), 70551 (MRI brain), 95816 (EEG)

SYNONYMS: Syncope, fainting, loss of consciousness, LOC, passing out, blackout, vasovagal syncope, neurocardiogenic syncope, reflex syncope, orthostatic syncope, cardiac syncope, convulsive syncope, presyncope, near-syncope, near syncope, TLOC, transient loss of consciousness

SCOPE: Evaluation and management of transient loss of consciousness (TLOC) due to syncope in adults. Includes risk stratification, etiologic workup, and treatment by type. Applies to ED, hospital, and outpatient settings. Excludes seizure, stroke, metabolic causes, and traumatic loss of consciousness.

DEFINITIONS: - Syncope: Transient loss of consciousness (TLOC) due to transient global cerebral hypoperfusion; characterized by rapid onset, short duration, and spontaneous complete recovery - Presyncope: Prodromal symptoms (lightheadedness, warmth, nausea) without loss of consciousness - Reflex (Neurally-Mediated) Syncope: Most common; includes vasovagal, situational, carotid sinus syncope - Orthostatic Syncope: Due to orthostatic hypotension from autonomic failure, hypovolemia, or medications - Cardiac Syncope: Due to arrhythmia or structural heart disease; highest mortality risk - Convulsive Syncope: Syncope with brief myoclonic jerks (not epilepsy); due to cerebral hypoperfusion

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

1. LABORATORY WORKUP¶

1A. Core Labs (All Patients)¶

Test	ED	HOSP	OPD	ICU	Rationale	Target Finding
Fingerstick glucose (CPT 82962)	STAT	STAT	ROUTINE	STAT	Hypoglycemia as cause	70-180 mg/dL
CBC (CPT 85025)	ROUTINE	ROUTINE	ROUTINE	ROUTINE	Anemia; hemorrhage	Normal
BMP (CPT 80048) (electrolytes, creatinine)	ROUTINE	ROUTINE	ROUTINE	ROUTINE	Electrolyte abnormalities	Normal
Troponin (CPT 84484)	STAT	STAT	-	STAT	Cardiac ischemia as trigger	Negative
BNP or NT-proBNP (CPT 83880)	ROUTINE	ROUTINE	-	ROUTINE	Heart failure; risk stratification	Normal
Pregnancy test (if applicable)	STAT	STAT	ROUTINE	-	Ectopic pregnancy; influences workup	Document

1B. Extended Labs (Based on Clinical Suspicion)¶

Test	ED	HOSP	OPD	ICU	Rationale	Target Finding
TSH (CPT 84443)	-	ROUTINE	ROUTINE	-	Thyroid dysfunction	Normal
Cortisol (CPT 82533) (AM)	-	EXT	EXT	-	Adrenal insufficiency if orthostatic	Normal
D-dimer (CPT 85379)	URGENT	URGENT	-	URGENT	If PE suspected	Negative
Toxicology screen	ROUTINE	ROUTINE	-	-	Drug/alcohol-induced	Negative
Blood cultures (CPT 87040)	-	ROUTINE	-	ROUTINE	If infection suspected	Negative

2. DIAGNOSTIC IMAGING & STUDIES¶

2A. Cardiac Studies (Priority Based on Risk)¶

Study	ED	HOSP	OPD	ICU	Timing	Target Finding	Contraindications
12-lead ECG (CPT 93000)	STAT	STAT	ROUTINE	STAT	Immediate; ALL patients	No arrhythmia, normal intervals	None
Continuous telemetry	-	ROUTINE	-	ROUTINE	If admitted	No arrhythmia	None
Transthoracic echocardiogram (CPT 93306)	URGENT	ROUTINE	ROUTINE	URGENT	If cardiac cause suspected	Normal structure/function	None
Exercise stress test	-	ROUTINE	ROUTINE	-	If exertional syncope	No ischemia, no arrhythmia	Acute MI, unstable angina
Cardiac MRI	-	EXT	EXT	-	Suspected cardiomyopathy, ARVC	Normal or define pathology	Pacemaker, metal

2B. Extended Cardiac Monitoring¶

Study	ED	HOSP	OPD	ICU	Timing	Target Finding	Contraindications
Holter monitor (CPT 93224) (24-48 hour)	-	-	ROUTINE	-	Frequent symptoms	Correlate symptoms with rhythm	None
Event recorder (CPT 93268) (2-4 weeks)	-	-	ROUTINE	-	Intermittent symptoms	Symptom-rhythm correlation	None
Insertable loop recorder (ILR)	-	-	ROUTINE	-	Infrequent, unexplained recurrent syncope	Identify arrhythmia	None
Electrophysiology study (EPS)	-	ROUTINE	EXT	-	Suspected arrhythmic cause; structural heart disease	Identify inducible arrhythmia	Active infection

2C. Autonomic Testing¶

Study	ED	HOSP	OPD	ICU	Timing	Target Finding	Contraindications
Orthostatic vital signs	STAT	STAT	ROUTINE	STAT	Immediate; ALL patients	No orthostatic hypotension	None
Tilt table test (CPT 95924)	-	-	ROUTINE	-	Suspected vasovagal if recurrent; dx uncertain	Positive = cardioinhibitory or vasodepressor	Severe CAD, critical AS
Carotid sinus massage	-	ROUTINE	ROUTINE	-	Age >40 with unexplained syncope (not if carotid bruit)	Negative (<3 sec pause, <50 mmHg drop)	Carotid bruit, recent stroke/TIA
Autonomic function tests (CPT 95924)	-	-	ROUTINE	-	Suspected autonomic failure	Characterize dysautonomia	Per test

2D. Neuroimaging (Select Cases Only)¶

Study	ED	HOSP	OPD	ICU	Timing	Target Finding	Contraindications
CT head (CPT 70450)	URGENT	ROUTINE	-	URGENT	Head trauma; focal neuro signs; NOT routine for syncope	No acute pathology	None (contrast: renal disease)
MRI brain (CPT 70551)	-	EXT	EXT	-	Atypical features suggesting CNS cause	Normal	Pacemaker, metal
EEG (CPT 95816)	-	EXT	EXT	-	If seizure suspected (prolonged LOC, postictal state, witnessed tonic-clonic)	No epileptiform activity	None
Carotid ultrasound	-	-	EXT	-	NOT indicated for typical syncope	N/A	None

3. TREATMENT¶

3A. Acute Management (ED/Hospital)¶

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
IV access	IV	-	N/A :: IV :: per protocol :: Establish if unstable	None	Access	STAT	STAT	-	STAT
IV fluid resuscitation	IV	-	500-1000 mL :: - :: once :: NS 500-1000 mL bolus if hypovolemic/dehydrated	Heart failure	Volume status	STAT	ROUTINE	-	STAT
Trendelenburg position	-	-	N/A :: - :: continuous :: Legs elevated if hypotensive	None	BP	STAT	ROUTINE	-	STAT
Telemetry monitoring	-	-	N/A :: - :: continuous :: Continuous if high-risk	None	Arrhythmia	STAT	ROUTINE	-	ROUTINE
Correct reversible causes	-	-	N/A :: - :: per protocol :: Treat hemorrhage, dehydration, arrhythmia, MI	Per condition	Per condition	STAT	STAT	-	STAT

3B. Vasovagal Syncope Treatment¶

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Education and reassurance	-	-	N/A :: - :: once :: Benign prognosis; triggers; warning signs	None	None	ROUTINE	ROUTINE	ROUTINE	-
Trigger avoidance	-	-	N/A :: - :: daily :: Identify and avoid (prolonged standing, heat, dehydration)	None	Recurrence	-	ROUTINE	ROUTINE	-
Counter-pressure maneuvers	-	-	N/A :: - :: per session :: Leg crossing, hand grip, arm tensing when prodrome felt	None	Effectiveness	-	ROUTINE	ROUTINE	-
Increased fluid/salt intake	PO	-	6-9 g :: PO :: - :: 2-3 L fluid/day; 6-9 g salt/day (if no HTN/HF)	HTN, heart failure	BP	-	ROUTINE	ROUTINE	-
Compression stockings	-	-	N/A :: - :: continuous :: Waist-high, 30-40 mmHg	Peripheral vascular disease	Compliance	-	-	ROUTINE	-
Tilt training	-	-	N/A :: - :: daily :: Progressive standing against wall; controversial efficacy	None	Tolerance	-	-	EXT	-
Fludrocortisone	PO	-	0.1-0.2 mg :: PO :: daily :: 0.1-0.2 mg daily (refractory cases)	HTN, HF	K+, BP, edema	-	-	ROUTINE	-
Midodrine	PO	-	2.5-10 mg :: PO :: TID :: 2.5-10 mg TID (refractory cases)	Supine HTN, urinary retention	Supine HTN	-	-	ROUTINE	-

3C. Orthostatic Syncope Treatment¶

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Identify/discontinue offending meds	-	-	N/A :: - :: per protocol :: Review diuretics, vasodilators, antihypertensives	Clinical judgment	BP	STAT	STAT	ROUTINE	STAT
Volume repletion	IV	-	N/A :: IV :: per protocol :: IV fluids acutely; oral fluids long-term (2-3 L/day)	Heart failure	Volume status	STAT	ROUTINE	ROUTINE	STAT
Salt supplementation	PO	-	6-10 g/day :: PO :: - :: 6-10 g/day if no HTN/HF	HTN, HF	BP	-	ROUTINE	ROUTINE	-
Compression garments	-	-	N/A :: - :: continuous :: Waist-high stockings 30-40 mmHg; abdominal binder	PVD	Compliance	-	-	ROUTINE	-
Elevate head of bed	-	-	N/A :: - :: continuous :: 10-20 degrees at night (reduces nocturnal diuresis)	None	Tolerance	-	ROUTINE	ROUTINE	-
Midodrine	PO	-	2.5-10 mg :: PO :: TID :: 2.5-10 mg TID; last dose before 6 PM	Supine HTN, urinary retention	Supine BP	-	ROUTINE	ROUTINE	-
Fludrocortisone	PO	-	0.1-0.3 mg :: PO :: daily :: 0.1-0.3 mg daily	HTN, HF, hypokalemia	K+, BP	-	ROUTINE	ROUTINE	-
Droxidopa (Northera)	-	-	100-600 mg :: - :: TID :: 100-600 mg TID; for neurogenic orthostatic hypotension	Supine HTN	Supine BP	-	-	ROUTINE	-
Pyridostigmine	PO	-	30-60 mg :: PO :: TID :: 30-60 mg TID; augments ganglionic transmission	Asthma, GI obstruction	Cholinergic effects	-	-	EXT	-

3D. Carotid Sinus Syncope Treatment¶

Treatment	Route	Indication	Dosing	Pre-Treatment Requirements	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Avoid tight collars, neck pressure	-	-	N/A :: - :: continuous :: Patient education	-	None	Recurrence	-	ROUTINE	ROUTINE	-
Dual-chamber pacemaker	-	-	N/A :: - :: continuous :: If cardioinhibitory type (pause >3 sec)	-	None	Device checks	-	ROUTINE	ROUTINE	-

3E. Cardiac Syncope Treatment¶

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Treat underlying arrhythmia	-	-	N/A :: - :: per protocol :: Per arrhythmia type	Per treatment	ECG, telemetry	STAT	STAT	ROUTINE	STAT
Pacemaker	-	-	N/A :: - :: continuous :: Sick sinus syndrome, high-grade AV block, bradycardia-induced syncope	None	Device checks	-	ROUTINE	ROUTINE	-
ICD (implantable cardioverter-defibrillator)	-	-	N/A :: - :: once :: Ventricular arrhythmias; high-risk cardiomyopathy	Terminal illness	Device checks	-	ROUTINE	ROUTINE	-
Catheter ablation	-	-	N/A :: - :: once :: Arrhythmia amenable to ablation (SVT, VT)	Extensive comorbidity	Recurrence	-	ROUTINE	ROUTINE	-
Treat structural heart disease	-	-	N/A :: - :: per protocol :: Aortic valve replacement for AS; revascularization for ischemia	Per condition	Per condition	STAT	ROUTINE	ROUTINE	STAT

4. OTHER RECOMMENDATIONS¶

4A. Risk Stratification (San Francisco Syncope Rule, EGSYS, OESIL, Canadian Syncope Risk Score)¶

High-Risk Features (Consider Admission)
Abnormal ECG (new changes, arrhythmia, ischemia, prolonged QTc, Brugada pattern)
History of heart failure or reduced LVEF
Syncope during exertion
Syncope while supine or sitting
Family history of sudden cardiac death
Structural heart disease
Significant anemia or GI bleeding
Abnormal vital signs (persistent hypotension, bradycardia)
Elevated troponin or BNP
No prodrome (sudden syncope without warning)
Palpitations before syncope
Age >60 with first syncope

4B. Referrals & Consults¶

Recommendation	ED	HOSP	OPD	ICU	Indication
Cardiology	URGENT	ROUTINE	ROUTINE	URGENT	Suspected cardiac syncope; abnormal ECG; structural heart disease
Electrophysiology	-	ROUTINE	ROUTINE	-	Arrhythmia evaluation; device consideration
Neurology	-	ROUTINE	EXT	-	If seizure suspected; atypical features
Autonomic disorders specialist	-	-	ROUTINE	-	Refractory orthostatic hypotension; complex dysautonomia

4C. Patient/Family Instructions¶

Recommendation	ED	HOSP	OPD
Recognize prodromal symptoms and immediately sit/lie down	ROUTINE	ROUTINE	ROUTINE
Counter-pressure maneuvers if prodrome (leg crossing, hand grip)	-	ROUTINE	ROUTINE
Avoid known triggers (prolonged standing, dehydration, heat)	-	ROUTINE	ROUTINE
Adequate hydration (2-3 L/day) and salt intake (if approved)	-	ROUTINE	ROUTINE
Rise slowly from lying/sitting; dangle legs before standing	-	ROUTINE	ROUTINE
Driving restrictions per state law; typically no driving until cause determined/treated	ROUTINE	ROUTINE	ROUTINE
Return if recurrent syncope, chest pain, palpitations, dyspnea	ROUTINE	ROUTINE	ROUTINE

4D. Driving & Activity Restrictions¶

Situation	Private Driving	Commercial Driving
Single vasovagal syncope with clear trigger	Usually OK immediately	Per regulations; often 3-12 months
Recurrent vasovagal syncope	Restrict until controlled	Often disqualifying
Unexplained syncope under investigation	Restrict until diagnosis	Restrict
Cardiac syncope (treated)	Per cardiologist; typically 6 months if ICD	Often disqualifying
Orthostatic syncope (treated)	When stable	Per individual assessment

5. DIFFERENTIAL DIAGNOSIS¶

Alternative Diagnosis	Key Distinguishing Features	Tests to Differentiate
Seizure	Tonic-clonic activity, tongue biting, prolonged postictal state, incontinence	EEG; witness description
Stroke/TIA	Focal neurologic deficits; usually no LOC unless brainstem	CT/MRI; neuro exam
Hypoglycemia	Diaphoresis, tremor, confusion; diabetes/insulin use	Fingerstick glucose
Psychogenic pseudosyncope	Eyes closed (vs. open in true syncope); prolonged duration; normal vitals during event	Tilt table with video EEG
Drop attack	Sudden fall without LOC; no prodrome	History; normal during event
Cataplexy	Triggered by emotion; with narcolepsy	Sleep study; history
Cardiac arrest	No pulse during event; does not spontaneously recover	Witnessed event; no pulse
Concussion	Preceded by head trauma	History
Vertebrobasilar insufficiency	Vertigo, diplopia, dysarthria; rare cause of syncope	MRA; history
Pulmonary embolism	Dyspnea, pleuritic chest pain, hypoxia; syncope in massive PE	D-dimer, CT-PA
Aortic dissection	Tearing chest/back pain; BP differential	CT angiography

6. MONITORING PARAMETERS¶

Parameter	ED	HOSP	OPD	ICU	Frequency	Target/Threshold	Action if Abnormal
Vital signs (including orthostatics)	STAT	q4-8h	Every visit	Continuous	Per setting	Stable; no orthostatic drop	Treat hypotension; volume
Continuous telemetry	-	Continuous	-	Continuous	Until risk stratified	No arrhythmia	Cardiology consult
ECG	STAT	Daily	Every visit if cardiac	STAT	Per clinical status	No new changes	Cardiology; treatment
Troponin	STAT	q6-8h × 2 if initially elevated	-	Per cardiac status	Until ruled out	Negative	Cardiology
Recurrence	-	Ongoing	Every visit	-	Ongoing	No recurrence	Re-evaluate diagnosis/treatment

7. DISPOSITION CRITERIA¶

Disposition	Criteria
Discharge from ED	Low-risk syncope (vasovagal with clear trigger, normal ECG, normal vitals, no cardiac history); reliable follow-up
Admit to telemetry	High-risk features (abnormal ECG, cardiac history, exertional, no prodrome, abnormal vitals); unexplained syncope in elderly
ICU admission	Hemodynamically unstable; malignant arrhythmia; acute MI; massive PE
Syncope unit/observation	Intermediate risk; brief observation with monitoring
Cardiology follow-up	Suspected cardiac cause; abnormal echo; need for device evaluation
Neurology follow-up	Atypical features suggesting seizure or neurologic cause
Primary care follow-up	Low-risk vasovagal syncope; medication review for orthostatic

8. EVIDENCE & REFERENCES¶

Recommendation	Evidence Level	Source
ECG for all syncope patients	Class I, Level B	ESC 2018 Syncope Guidelines
Echo if cardiac cause suspected	Class I, Level B	ESC 2018; AHA/ACCF 2017
Tilt test for recurrent vasovagal syncope	Class IIa, Level B	ESC 2018
Pacemaker for cardioinhibitory carotid sinus syncope	Class I, Level B	ESC 2018
ILR for recurrent unexplained syncope	Class I, Level A	ISSUE-3 trial; ESC 2018
Counter-pressure maneuvers for vasovagal	Class IIa, Level B	PC-Trial
Midodrine for refractory orthostatic hypotension	Class IIa, Level B	Multiple RCTs
Risk stratification scores (Canadian Syncope Risk Score)	Class IIa, Level B	Thiruganasambandamoorthy et al.

NOTES¶

Syncope is common (1-3% of ED visits); most are benign reflex syncope
Cardiac syncope has highest mortality (up to 30% at 1 year); must be ruled out
The history is the most important diagnostic tool (triggers, prodrome, position, witnesses)
"Red flags" for cardiac syncope: exertional, supine, no prodrome, family history SCD, structural heart disease
ECG is mandatory for ALL syncope patients
Routine neuroimaging (CT, MRI) is NOT indicated for typical syncope without focal signs
EEG is NOT indicated unless seizure is suspected
Convulsive syncope (brief myoclonic jerks) is common and does NOT indicate epilepsy
Insertable loop recorder (ILR) has high diagnostic yield for unexplained recurrent syncope
Driving restrictions vary by state/country; counsel patients appropriately
Many patients do not require extensive workup if history clearly suggests vasovagal syncope

CHANGE LOG¶

v1.0 (January 29, 2026) - Initial template creation - Risk stratification criteria included - Treatment by syncope type (vasovagal, orthostatic, cardiac, carotid sinus) - Driving restrictions addressed - ESC 2018 guidelines incorporated