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

Initial Approach to Syncope

The initial approach to a patient presenting with syncope should include a comprehensive cardiac evaluation with continuous ECG monitoring, especially for patients with high-risk features such as syncope while sitting without prodrome, abnormal ECG findings, history of structural heart disease, or age >60 years. 1

Initial Evaluation

The initial evaluation should focus on three key components:

1. Detailed History

   • Circumstances surrounding the event (position, activity, prodromal symptoms)
   • Duration of loss of consciousness
   • Recovery pattern (confusion, nausea, pallor)
   • Witness accounts
   • Previous episodes
   • Family history of sudden cardiac death
   • Medication review

2. Physical Examination

   • Vital signs including orthostatic measurements
   • Cardiovascular examination (murmurs, irregular rhythm)
   • Neurological assessment
   • Carotid sinus massage in selected patients >40 years (if no contraindications)

3. 12-lead ECG

   • Look for conduction abnormalities, arrhythmias, QT prolongation, Brugada pattern, pre-excitation, or evidence of structural heart disease

This initial evaluation can diagnose up to 50% of syncope cases and allows for immediate risk stratification 1, 2.

Risk Stratification

High-risk features requiring urgent evaluation:

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

Patients with these features should be considered for hospital admission for further evaluation 1.

Diagnostic Testing

Based on initial evaluation, select appropriate diagnostic tests:

1. For all hospitalized patients with suspected cardiac etiology:

   • Continuous ECG monitoring (Class I recommendation) 1

2. For suspected structural heart disease:

   • Echocardiogram (Class IIa recommendation) 1

3. For suspected arrhythmic etiology:

   • Extended cardiac monitoring (24-48 hour Holter or 30-day event monitor)
   • Electrophysiological study (EPS) in selected patients (Class IIa recommendation) 1

4. For suspected vasovagal syncope:

   • Tilt-table testing if orthostatic testing is negative (Class IIa recommendation) 1

5. For syncope during exertion:

   • Exercise stress testing (Class IIa recommendation) 1

Tests to Avoid Without Specific Indications

• MRI/CT of head
• Carotid artery imaging
• Routine EEG

These tests have a Class III: No Benefit recommendation 1.

Classification and Management Approach

1. Cardiac Syncope (15-20%)

• Highest mortality risk (18-33% at 1 year)
• Requires specialist referral and specific treatment based on etiology
• May require cardiac device placement or ablation

2. Reflex (Neurally Mediated) Syncope (75%)

• Most common type, especially in younger patients
• Management includes:
  • Trigger avoidance
  • Physical counter-pressure maneuvers
  • Adequate hydration
  • In severe cases, pharmacotherapy

3. Orthostatic Hypotension

• Defined as >20 mmHg drop in systolic BP or >20 bpm increase in heart rate within 3 minutes of standing
• Management includes:
  • Medication review and adjustment
  • Volume expansion
  • Compression stockings
  • Pharmacotherapy in severe cases

Common Pitfalls to Avoid

1. Dismissing cardiac causes when initial ECG is normal - Intermittent arrhythmias may require extended monitoring 1

2. Assuming orthostatic hypotension is ruled out by a single negative test - Delayed orthostatic hypotension may take >3 minutes to develop 1

3. Focusing on neurological causes before excluding cardiac etiologies - Cardiac causes are more life-threatening and should be ruled out first 1

4. Failing to recognize presyncope - Patients with presyncope have similar prognoses to those with syncope and should undergo similar evaluation 2

5. Overuse of neuroimaging - Low diagnostic yield unless specific neurological symptoms are present 1

Follow-up

• Schedule follow-up within 2-4 weeks for first episode
• Earlier follow-up for recurrent episodes
• Provide patient education on trigger avoidance and when to seek immediate medical attention 1

The structured approach to syncope evaluation using risk stratification reduces hospital admissions, lowers medical costs, and increases diagnostic accuracy 2, 3.