What is the initial approach to a patient presenting with syncope?

Initial Approach to Syncope

The initial evaluation of a patient with syncope must include a detailed history, physical examination with orthostatic blood pressure measurements, and a 12-lead ECG, followed by risk stratification to guide further management. 1

Initial Assessment

History Taking

• Focus on circumstances before, during, and after the event:
  • Posture when syncope occurred (standing, sitting, supine)
  • Activity at onset (exertion, rest, position change)
  • Presence of prodromal symptoms (lightheadedness, nausea, sweating)
  • Duration of loss of consciousness
  • Recovery pattern (confusion, muscle pain, injury)
  • Witness accounts if available

Physical Examination

1. Complete cardiovascular examination
2. Orthostatic vital signs (measure BP and HR in lying, sitting, and standing positions)
3. Neurological examination when indicated by focal findings
4. Look for signs of injury from fall

Immediate Testing

• 12-lead ECG for all patients with syncope (Class I recommendation) 1
• Basic laboratory tests only if clinically indicated (not routine)

Risk Stratification

High-Risk Features (Require Admission)

• Age >60 years
• Male sex
• Known cardiac disease (structural or arrhythmic)
• Brief or absent prodrome
• Syncope during exertion
• Syncope in supine position
• Abnormal cardiac examination
• Family history of sudden cardiac death
• Abnormal ECG findings

Low-Risk Features (Can Be Managed as Outpatient)

• Younger age
• No known cardiac disease
• Syncope only when standing
• Clear positional trigger
• Typical prodrome present
• Specific situational triggers
• Recurrent episodes with similar characteristics

Immediate Management

For Presyncope

1. Maintain or assume a safe position (sitting or lying down) to prevent injury (Class I, C-LD) 2
2. Use physical counterpressure maneuvers (PCMs) once in safe position (Class IIa, C-LD) 2
   • Lower-body PCMs preferred (squatting, leg crossing)
   • If no improvement within 1-2 minutes or symptoms worsen, activate emergency services

For All Syncope Patients

• Identify and address any life-threatening causes immediately
• Discontinue or reduce vasodilator medications if possible 2
• For vasovagal syncope, consider volume expansion (increased salt/fluid intake) 2

Diagnostic Testing Based on Suspected Etiology

Suspected Cardiac Syncope

• Continuous ECG monitoring for hospitalized patients
• Echocardiogram when structural heart disease suspected
• Consider electrophysiology study for suspected arrhythmias

Suspected Reflex (Neurally Mediated) Syncope

• Tilt-table testing for recurrent unexplained syncope
• Education on trigger avoidance and physical counterpressure maneuvers

Suspected Orthostatic Hypotension

• Volume expansion strategies
• Review and modify medications that may exacerbate hypotension

Important Caveats

• Avoid unnecessary testing: Routine comprehensive laboratory testing and neuroimaging have low diagnostic yield and are not recommended without specific indications 1
• Presyncope should be evaluated similarly to syncope, as outcomes are comparable 3
• Cardiac syncope carries higher mortality (18-33% at 1 year) compared to non-cardiac causes (3-4%) 1
• The initial evaluation may diagnose up to 50% of patients and allows immediate risk stratification 3
• PCMs should not be used when symptoms of heart attack or stroke accompany presyncope 2

Remember that the primary goals of syncope management are to prolong survival, prevent injuries, and prevent recurrences 4. A standardized approach reduces hospital admissions, medical costs, and increases diagnostic accuracy 1.