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

Syncope Evaluation and Management

The appropriate workup for syncope should begin with a detailed history, physical examination with orthostatic blood pressure measurements, and a 12-lead ECG, which can establish the diagnosis in 23-50% of cases. 1

Initial Evaluation

History

Focus on specific elements:

• Position when syncope occurred (supine, sitting, standing)
• Activity at time of event (rest, posture change, exercise, after urination/defecation)
• Predisposing factors (crowded places, prolonged standing, post-meal)
• Prodromal symptoms (nausea, sweating, blurred vision)
• Eyewitness account (fall pattern, skin color, duration of unconsciousness)
• Post-event symptoms (confusion, muscle aches, incontinence)
• Medical history (cardiac disease, neurological disorders, medications) 2

Physical Examination

• Complete cardiovascular examination
• Orthostatic blood pressure measurements (essential)
• Neurological examination if non-syncopal loss of consciousness is suspected 1

Initial Testing

• 12-lead ECG (Class I recommendation) 2, 1
• Basic laboratory tests only if volume depletion or metabolic disorder is suspected 2

Risk Stratification

High-Risk Features (requiring hospitalization):

• Age >60 years
• Known structural heart disease or abnormal ECG
• Brief or absent prodrome
• Syncope during exertion or in supine position
• Family history of sudden cardiac death
• Abnormal cardiac examination 1

Low-Risk Features (can be managed outpatient):

• Younger age
• No known cardiac disease
• Clear positional trigger
• Typical prodrome
• Frequent recurrence with similar characteristics 1

Diagnostic Algorithm Based on Initial Findings

If Cardiac Syncope Suspected:

1. Echocardiography (if structural heart disease suspected)
2. Prolonged ECG monitoring (type depends on frequency of events)
3. Exercise stress testing (for exertional syncope)
4. Electrophysiological studies (if above tests non-diagnostic) 2, 1

If Neurally-Mediated Syncope Suspected:

1. Tilt table testing
2. Carotid sinus massage (especially in older patients or syncope with neck turning) 2

If Orthostatic Hypotension Suspected:

1. Lying-to-standing orthostatic testing
2. Autonomic function testing if indicated 1

Common Pitfalls to Avoid

• Overuse of neuroimaging (only indicated when neurological event suspected)
• Routine comprehensive laboratory testing without clinical indication
• Missing orthostatic hypotension
• Overlooking medication-related causes
• Failure to distinguish between different types of dizziness 1

Unexplained Syncope

If initial evaluation and directed testing do not yield a diagnosis:

1. Reappraise the entire workup
2. Consider prolonged monitoring with implantable loop recorder
3. Consider psychiatric assessment for patients with frequent episodes and multiple somatic complaints 2

Treatment Approach

Treatment should be directed at the underlying cause:

• Cardiac syncope: Treat the specific arrhythmia or structural abnormality
• Orthostatic hypotension: Volume expansion, compression garments, medication adjustment
• Neurally-mediated syncope: Education on trigger avoidance, physical counterpressure maneuvers

The European Society of Cardiology and American Heart Association guidelines emphasize that the diagnostic yield of the initial evaluation (history, physical exam, and ECG) is high, and additional testing should be guided by these initial findings rather than performed routinely 1.