What is the appropriate workup and treatment for a patient presenting with syncope?

Syncope Workup and Management

The appropriate workup for syncope requires a 12-lead ECG for all patients, risk stratification to determine disposition, and targeted diagnostic testing based on suspected etiology, with treatment directed at the underlying cause. 1

Initial Evaluation

Essential Components

• 12-lead ECG: Required for all patients with syncope (Class I, B-NR) 1
• Detailed history: Focus on:
  • Circumstances before, during, and after the event
  • Presence of prodromal symptoms (weakness, headache, blurred vision, diaphoresis)
  • Position when syncope occurred (standing, sitting, supine)
  • Activity at onset (exertion, micturition, defecation, coughing)
  • Presence of chest pain, palpitations, or dyspnea
  • Duration of unconsciousness and recovery pattern
  • Witness accounts
• Physical examination:
  • Vital signs including orthostatic measurements
  • Cardiovascular examination (murmurs, irregular rhythm)
  • Neurological assessment

Risk Stratification

High-Risk Features (Require Hospital Admission) 1

• Age >60 years
• Abnormal ECG findings
• History of heart failure or structural heart disease
• Syncope during exertion or while supine
• Absence of prodrome
• Family history of sudden cardiac death

Low-Risk Features (Consider Outpatient Management) 1

• Younger age (<45 years)
• Normal ECG
• No known cardiac disease
• Clear trigger with prodromal symptoms
• Recurrent episodes with similar presentation

Intermediate-Risk Features

• Consider structured emergency department observation protocol 1

Diagnostic Testing

First-Line Tests

• 12-lead ECG: All patients (Class I, B-NR) 1
• Orthostatic vital signs: Particularly important when orthostatic hypotension is suspected 1

Second-Line Tests (Based on Initial Findings)

• Continuous ECG monitoring: For hospitalized patients with suspected cardiac etiology (Class I, B-NR) 1
• Echocardiogram: When structural heart disease is suspected (Class IIa, B-NR) 1
• Exercise stress testing: When syncope occurs during exertion (Class IIa, C-LD) 1
• Tilt-table testing: For suspected vasovagal syncope, delayed orthostatic hypotension, or to distinguish convulsive syncope from epilepsy (Class IIa, B-R) 1
• Electrophysiological study (EPS): For selected patients with suspected arrhythmic etiology (Class IIa, B-NR) 1
• Implantable cardiac monitor: Consider for patients with infrequent symptoms (>30 days between episodes) (Class IIa, B-R) 1

Tests NOT Routinely Recommended 1

• MRI/CT of head (Class III: No Benefit)
• Carotid artery imaging (Class III: No Benefit)
• Routine EEG (Class III: No Benefit)
• Laboratory testing (only if clinically indicated)

Treatment Based on Etiology

Neurally Mediated (Vasovagal) Syncope 1, 2

• Education on trigger avoidance
• Physical counterpressure maneuvers
• Increased salt and fluid intake
• Consider pharmacotherapy for recurrent cases:
  • Midodrine (if no hypertension)
  • Beta-blockers (e.g., propranolol)
  • Fludrocortisone
  • Serotonin reuptake inhibitors in selected cases

Orthostatic Hypotension 1, 2

• Non-pharmacological approaches:
  • Avoid rapid position changes
  • Increase fluid and sodium intake
  • Compression garments
  • Postural counter-maneuvers
• Pharmacological options:
  • Midodrine
  • Fludrocortisone
  • Droxidopa

Cardiac Syncope 1, 3

• Treatment directed at underlying cardiac condition
• Arrhythmia management:
  • Antiarrhythmic medications
  • Pacemaker for bradyarrhythmias
  • ICD for ventricular arrhythmias
  • Catheter ablation for specific arrhythmias
• Structural heart disease:
  • Valve repair/replacement
  • Treatment of heart failure
  • Surgical correction of obstructive lesions

Follow-Up and Patient Education

Patient Instructions 1

• Seek immediate medical attention if:
  • Syncope occurs during exertion
  • Palpitations occur before syncope
  • Syncope occurs without warning
  • Family history of sudden death is discovered

Driving Restrictions 1

• 1-month restriction for syncope of undetermined etiology
• 3-month restriction for cardiac cause after treatment
• No restriction for reflex syncope with clear trigger if trigger can be avoided

Important Considerations

• Cardiac causes of syncope are associated with higher mortality (18-33% at 1 year) compared to non-cardiac causes (3-4%) 1
• Syncope follows a trimodal distribution with peaks around ages 20,60, and 80 years 1
• Patients with presyncope should undergo similar evaluation as those with syncope 3
• A standardized approach to syncope evaluation reduces hospital admissions and medical costs 3
• The ECG may identify the cause of syncope in approximately 7% of patients presenting to the emergency department 4