What are the typical symptoms of the prodrome of syncope?

Typical Prodrome of Syncope

The typical prodrome of syncope includes dizziness/lightheadedness, weakness, fatigue, nausea, sweating, palpitations, visual disturbances (blurring, enhanced brightness, tunnel vision), hearing disturbances (impaired hearing, crackles, tinnitus), and pain in the neck, shoulders, lower back, or precordial region. 1

Common Prodromal Symptoms by Frequency

Very Common Symptoms:

• Dizziness/lightheadedness
• Visual disturbances (blurring, tunnel vision, enhanced brightness)
• Weakness/fatigue
• Pallor
• Sweating

Common Symptoms:

• Nausea/abdominal discomfort
• Palpitations
• Feeling warm or cold
• Hearing disturbances (tinnitus, impaired hearing)
• Pain in neck/shoulders/back

Timing and Progression of Prodrome

The timing and progression of prodromal symptoms vary depending on the type of syncope:

• Initial orthostatic hypotension: Symptoms occur within 0-30 seconds of standing 1
• Classical orthostatic hypotension: Symptoms develop within 30 seconds to 3 minutes of standing 1
• Delayed orthostatic hypotension: Symptoms develop between 3-30 minutes of standing 1
• Reflex syncope (vasovagal): Clear prodrome with gradual onset over minutes 1

Prodromal Symptoms by Syncope Type

Reflex (Neurally Mediated) Syncope:

• Typically has a longer and more pronounced prodrome
• Prominent autonomic activation (sweating, nausea, pallor)
• Often triggered by emotional distress, prolonged standing, or specific situations 1

Orthostatic Hypotension:

• Symptoms directly related to positional change
• Dizziness, pre-syncope, fatigue, weakness
• Visual and hearing disturbances
• In delayed orthostatic hypotension: prolonged prodrome with hyperhydrosis and pain 1

Cardiac Syncope:

• Often has minimal or no prodrome
• When present, may include palpitations and shortness of breath
• Sudden onset with little warning 1

Clinical Pearls and Pitfalls

Important Clinical Considerations:

• The presence and duration of prodromal symptoms help differentiate between types of syncope
• Vasovagal syncope typically has the most pronounced prodrome 1
• Cardiac syncope often has minimal prodrome, making it more dangerous 1
• Older adults may have atypical or less pronounced prodromal symptoms 1

Common Pitfalls:

• Failing to recognize prodromal symptoms as warning signs of impending syncope
• Not distinguishing between the prodrome of different syncope types
• Missing cardiac syncope due to its minimal prodromal symptoms
• Overlooking orthostatic hypotension in older adults or those on vasoactive medications 1

Management During Prodrome

When prodromal symptoms occur:

1. Immediately assume a safe position (sitting or lying down)
2. Implement physical counterpressure maneuvers:
   • Leg crossing with muscle tension
   • Arm tensing
   • Squatting
   • Neck flexion 1, 2

These interventions can abort the syncopal episode if performed during the prodromal phase.

Risk Assessment

The presence and characteristics of prodromal symptoms should be used in risk stratification:

• Minimal or absent prodrome with exertional syncope suggests higher risk of cardiac origin
• Clear, prolonged prodrome with typical triggers suggests reflex syncope with better prognosis 1

Understanding the typical prodrome of syncope is crucial for early intervention, proper diagnosis, and prevention of complete loss of consciousness and potential injury.