One-liner#

Risk-stratify syncope to identify cardiac causes (arrhythmia, structural) requiring urgent evaluation, then efficiently manage the common benign causes (vasovagal, orthostatic) without over-testing low-risk patients. (Per 2017 ACC/AHA/HRS Syncope Guidelines and 2018 ESC Syncope Guidelines)

Quick nav#

• Red flags / send to ED
• Key history
• Focused exam
• Differential (quick pattern recognition)
• Workup
• Initial management
• Management by diagnosis
• Follow-up
• Patient instructions
• Smartphrase snippets

Red flags / send to ED#

• Syncope during exertion (not after)
• Syncope while supine or seated
• Syncope preceded by palpitations or chest pain
• Family history of sudden cardiac death <50 years
• Known structural heart disease (HCM, severe AS, arrhythmogenic cardiomyopathy, prior MI with reduced EF)
• Abnormal ECG: long QT, short QT, Brugada pattern, WPW, bifascicular block, Q waves suggesting prior MI
• New neurologic deficits (stroke mimic)
• Significant injury from fall (head trauma, fracture)
• Recurrent syncope without clear trigger
• Syncope in patient with pacemaker/ICD (device malfunction)

Key history#

Characterize the event:

• True syncope (complete LOC with spontaneous recovery) vs presyncope (near-faint) vs other (seizure, vertigo, hypoglycemia)
• Duration of LOC (seconds = typical syncope; prolonged = seizure or cardiac arrest with resuscitation)
• Prodrome: lightheadedness, warmth, nausea, tunnel vision, diaphoresis (vasovagal) vs none (cardiac)
• Position: standing (orthostatic, vasovagal) vs sitting/supine (cardiac more likely)
• Activity: exertional (cardiac) vs post-exertional (vasovagal) vs at rest

Triggers and context:

• Prolonged standing, hot environment, dehydration, pain, blood draw, emotional stress (vasovagal)
• Positional change: lying to standing (orthostatic)
• Micturition, defecation, coughing, swallowing (situational)
• Head turning, shaving, tight collar (carotid sinus hypersensitivity—elderly)
• Medications: antihypertensives, diuretics, vasodilators, QT-prolonging drugs

Witness account (critical):

• Movements during LOC: brief myoclonic jerks (common in syncope) vs sustained tonic-clonic activity (seizure)
• Color: pallor (syncope) vs cyanosis (seizure, cardiac arrest)
• Duration of confusion after: immediate recovery (syncope) vs prolonged postictal state (seizure)
• Pulse during event if checked

Risk factors for cardiac syncope:

• Age >60
• Known heart disease: CAD, HF, valvular disease, cardiomyopathy
• Family history: sudden death <50, HCM, long QT, Brugada, ARVC
• Palpitations preceding syncope
• Exertional syncope
• Syncope while supine

Focused exam#

• Vitals: orthostatic BP and HR (lying → standing at 1 and 3 minutes; positive if SBP drop ≥20 or DBP drop ≥10 with symptoms)
• Cardiac: murmurs (AS, HCM), irregular rhythm, S3 (HF), JVD
• Carotid: bruits (avoid carotid massage if bruit present)
• Neuro: focal deficits (stroke), tongue laceration (seizure), postictal confusion
• Skin: pallor, diaphoresis, injuries from fall
• Rectal: if GI bleed suspected (melena, anemia)

Differential (quick pattern recognition)#

Common/likely (outpatient)#

Can’t-miss / urgent#

Workup#

All patients:

• ECG: look for arrhythmia, long/short QT, Brugada, WPW, heart block, prior MI (Q waves), LVH
• Orthostatic vitals (lying → standing)
• Basic labs: CBC (anemia), BMP (electrolytes, glucose), consider troponin if cardiac concern

Risk stratification tools:

Canadian Syncope Risk Score (CSRS) — validated for 30-day serious adverse events:

• Predisposition to vasovagal: −1 point
• Heart disease history or elevated BNP: +1 point
• SBP <90 or >180 mmHg: +2 points
• Elevated troponin: +2 points
• Abnormal QRS axis: +1 point
• QRS >130 ms: +1 point
• QTc >480 ms: +2 points
• ED diagnosis of cardiac syncope: +2 points
• ED diagnosis of vasovagal syncope: −2 points

San Francisco Syncope Rule — older, less validated; CSRS preferred per 2017 ACC/AHA/HRS guidelines.

High-risk features (consider ED/admission):

• Abnormal ECG
• History of CHF or structural heart disease
• Hematocrit <30%
• Systolic BP <90
• Shortness of breath
• Age >60 with no clear vasovagal trigger

Low-risk features (outpatient workup appropriate):

• Classic vasovagal prodrome and trigger
• Young, healthy, normal ECG
• Orthostatic hypotension with clear medication cause
• Situational syncope with identifiable trigger

Extended workup by clinical scenario:

When to consider implantable loop recorder (ILR):

Per 2017 ACC/AHA/HRS guidelines, ILR is indicated (Class I) for:

• Recurrent unexplained syncope after initial evaluation (ECG, orthostatics, echo if indicated) is non-diagnostic
• Infrequent episodes (<monthly) unlikely to be captured by external monitors
• High-risk features but no diagnosis after initial workup
• Syncope causing significant injury requiring definitive diagnosis

ILR practical considerations:

• Device cost: $5,000–10,000 (often covered by insurance with appropriate documentation)
• Battery life: 3+ years of continuous monitoring
• Implantation: minor outpatient procedure by cardiology/EP
• Yield: diagnoses arrhythmia in 35–45% of unexplained syncope cases
• Refer to cardiology/EP for implantation decision

Carotid sinus massage (CSM):

Indicated for: unexplained syncope in patients >40 years, especially with head-turning triggers

Technique (perform with continuous ECG and BP monitoring):

• Patient supine with IV access available
• Massage one carotid at a time for 5–10 seconds
• Positive if reproduces symptoms with asystole >3 seconds or SBP drop >50 mmHg

Contraindications to CSM:

• Carotid bruit
• History of stroke/TIA within 3 months
• Known carotid stenosis >50%
• History of VT/VF
• Recent MI

| Suspected seizure | EEG; MRI brain; neurology referral | | Suspected PE | Wells score; D-dimer or CT-PA |

When NOT to do extensive workup:

• Single episode with classic vasovagal features, clear trigger, normal ECG, young healthy patient
• Clear orthostatic hypotension from identifiable medication

Initial management#

• Address immediate safety: driving restrictions until diagnosis clarified and treated
• Treat reversible causes: stop/reduce offending medications; rehydrate
• Risk stratify: low-risk patients can be managed outpatient; high-risk need ED/cardiology
• Document: detailed history including witness account, ECG findings, orthostatic vitals

Management by diagnosis#

Vasovagal syncope#

Education:

• Most common cause of syncope; not dangerous but can cause injury from falls
• Recognize prodrome (lightheadedness, warmth, nausea) and respond immediately
• Counterpressure maneuvers can abort episodes

Treatment:

Non-pharmacologic (first-line):

• Recognize and avoid triggers when possible
• At prodrome: lie down immediately, or if unable, cross legs and squeeze, squat, or grip hands tightly (counterpressure)
• Increase fluid intake (2–3 L/day) and salt intake (if no HTN/HF)
• Avoid prolonged standing; shift weight frequently
• Compression stockings (waist-high more effective than knee-high)

Pharmacologic (if refractory and frequent):

Per 2017 ACC/AHA/HRS guidelines, pharmacotherapy has limited evidence (Class IIb) and should be reserved for patients with frequent, recurrent vasovagal syncope despite non-pharmacologic measures.

Follow-up: 4–6 weeks if starting treatment; PRN if infrequent with good prodrome recognition. Driving restrictions per state law (typically no driving until symptom-free for specified period).

Orthostatic hypotension#

Education:

• Blood pressure drops when standing, causing lightheadedness or fainting
• Often medication-related or from dehydration
• Gradual position changes and countermeasures help

Treatment:

Non-pharmacologic (first-line):

• Rise slowly: sit at bedside before standing; wait 1–2 minutes
• Increase fluid intake (2–3 L/day unless contraindicated)
• Increase salt intake (if no HTN/HF)
• Compression stockings (waist-high)
• Elevate head of bed 10–20 degrees (reduces nocturnal diuresis)
• Avoid large meals, alcohol, hot environments

Medication review:

• Reduce/stop offending agents: diuretics, alpha-blockers, vasodilators, tricyclics, antipsychotics
• Time antihypertensives to avoid peak effect during high-risk activities

Pharmacologic (if refractory):

Follow-up: 2–4 weeks after medication changes; recheck orthostatic vitals. Consider autonomic specialist referral if refractory.

Managing supine hypertension (common with midodrine/fludrocortisone):

• Elevate head of bed 10–20 degrees
• Avoid supine position during day; last midodrine dose by 6 PM
• If severe (SBP >180 supine): may need to reduce pressor dose or add bedtime short-acting antihypertensive (captopril 25 mg, losartan 25 mg, or hydralazine 25 mg)
• Balance: some supine HTN is acceptable if orthostatic symptoms are controlled

When orthostatics are falsely negative:

• Patient may be volume-repleted at time of testing (just drank fluids)
• Symptoms may be postprandial (test after meals)
• Autonomic dysfunction may require prolonged standing (10+ minutes) to manifest
• Consider repeat testing or tilt table if high clinical suspicion

Cardiac syncope (arrhythmia, structural)#

Education:

• Cardiac syncope is potentially life-threatening and requires thorough evaluation
• Activity restrictions until cleared by cardiology
• May require device therapy (pacemaker, ICD) or ablation

Treatment:

Immediate:

• Cardiology referral (urgent if high-risk features)
• Activity restriction: no driving, avoid heights, avoid swimming alone
• Treat underlying condition per cardiology guidance

By etiology (cardiology-directed):

Follow-up: Per cardiology. PCP role is coordination, medication management, and ensuring compliance with activity restrictions.

Situational syncope#

Education:

• Triggered by specific activities (urination, defecation, coughing, swallowing)
• Benign but can cause injury; prevention is key
• Same mechanism as vasovagal (vagal activation)

Treatment:

Non-pharmacologic:

• Sit during triggering activities (especially micturition syncope—sit to urinate)
• Avoid straining (treat constipation, suppress cough)
• Stay hydrated
• Recognize prodrome and use counterpressure maneuvers

Pharmacologic:

• Rarely needed; same agents as vasovagal if refractory

Follow-up: PRN; reassurance is usually sufficient.

Follow-up#

• Vasovagal, single episode, low risk: PRN; return if recurrent or change in pattern
• Orthostatic hypotension: 2–4 weeks after intervention to recheck vitals
• Cardiac syncope: per cardiology; PCP coordinates care
• Unexplained recurrent: ensure monitoring completed; consider implantable loop recorder referral

Driving restrictions:

• Varies by state and diagnosis
• General guidance (verify local requirements):
  • Vasovagal with prodrome: typically can drive once trigger avoidance strategies in place; some states require symptom-free period (often 1–3 months)
  • Vasovagal without prodrome: longer restriction (3–6 months symptom-free)
  • Cardiac syncope: no driving until treated and cleared by cardiology (often 6 months for ICD, 1 week for pacemaker)
  • Unexplained syncope: no driving until diagnosis established
• Commercial drivers: stricter requirements; often need cardiology clearance and longer symptom-free periods
• Document counseling in chart

Elderly patients with multifactorial syncope:

• Common scenario: orthostatic hypotension + polypharmacy + carotid sinus hypersensitivity + arrhythmia
• Address ALL contributing factors, not just the most obvious one
• Medication reconciliation is critical—often multiple culprits
• Lower threshold for cardiology referral
• Fall risk assessment and home safety evaluation

Patient instructions#

• If you feel faint (lightheaded, warm, nauseated), lie down immediately or sit and put your head between your knees.
• If you can’t lie down, cross your legs and squeeze your thighs together, or grip your hands and tense your arms—this can prevent fainting.
• Rise slowly from lying or sitting; sit at the edge of the bed before standing.
• Drink plenty of fluids (unless your doctor has restricted fluids) and don’t skip meals.
• Avoid prolonged standing, hot environments, and alcohol.
• Do not drive until your doctor says it’s safe.
• Seek immediate care if you faint during exercise, have chest pain or palpitations before fainting, or injure yourself during a faint.

Smartphrase snippets#

• Syncope, vasovagal: Classic prodrome (lightheadedness, warmth, nausea) with identifiable trigger (prolonged standing). Rapid recovery, no confusion. Normal ECG, negative orthostatics. Low risk. Discussed counterpressure maneuvers, hydration, trigger avoidance, and return precautions.

• Syncope, orthostatic hypotension: Syncope/presyncope with position change. Orthostatic vitals positive (supine BP X, standing BP Y with symptoms). Likely medication-related [or dehydration]. Adjusted [medication]. Discussed slow position changes, hydration, and follow-up.

• Syncope, high risk features: [Describe features]. ECG shows [findings]. Referred to cardiology urgently. Advised no driving until cleared. Discussed return precautions.

Related pages#

• Dizziness/Vertigo — if presyncope vs vertigo unclear
• Palpitations — if arrhythmia suspected
• Orthostatic hypotension — detailed orthostasis management
• Falls (geriatric) — if fall with syncope in elderly
• Chest pain — if cardiac syncope suspected

Coding/billing notes#

• Document detailed history including prodrome, triggers, position, activity, witness account
• Document orthostatic vitals with timing and symptoms
• Document ECG interpretation
• Document risk stratification reasoning
• Document driving counseling
• If not pursuing extensive workup, document rationale (e.g., “classic vasovagal with clear trigger, normal ECG, low-risk features”)

Key references#

• 2017 ACC/AHA/HRS Guideline for the Evaluation and Management of Patients With Syncope (Circulation 2017)
• 2018 ESC Guidelines for the Diagnosis and Management of Syncope (Eur Heart J 2018)
• Canadian Syncope Risk Score validation (CMAJ 2016)
• POST trial: beta-blockers in vasovagal syncope (Circulation 2006)