Emotional Syncope Terminology
Emotional syncope is formally called "vasovagal syncope" or "classical vasovagal syncope" when triggered by emotional distress such as fear, pain, or anxiety. 1, 2
Primary Terminology
Vasovagal syncope (VVS) is the preferred and most widely accepted term for syncope triggered by emotional stimuli. 1 The European Society of Cardiology specifically designates syncope precipitated by fear, severe pain, emotional distress, instrumentation, or blood phobia as "classical vasovagal syncope" to distinguish it from orthostatic vasovagal syncope. 2
Alternative Accepted Terms
Several synonymous terms exist in the medical literature, though they are less preferred:
Neurally-mediated syncope: This is recognized as an acceptable synonym for reflex syncope (including vasovagal syncope), emphasizing the role of the autonomic nervous system. 1 However, it is longer and less specific than "vasovagal syncope." 1
Neurocardiogenic syncope: This term appears in older literature but is now discouraged for general use. 1 The European Society of Cardiology recommends restricting this term strictly to cases where the reflex trigger originates in the heart itself, not for emotional triggers. 1
Reflex syncope: This is the broader category that encompasses vasovagal syncope, situational syncope, and carotid sinus syncope. 1 Emotional vasovagal syncope is a specific subtype within this classification. 1
Classification Within Syncope Categories
Emotional vasovagal syncope falls under the category of reflex (neurally-mediated) syncope, which is distinct from:
- Orthostatic hypotension syncope: Caused by autonomic failure or volume depletion 1
- Cardiac syncope: Due to arrhythmias or structural heart disease 1
- Situational syncope: Triggered by specific physical actions like coughing, micturition, or defecation 1, 3
Diagnostic Criteria for Emotional Vasovagal Syncope
The diagnosis is established clinically when:
- Precipitating emotional triggers are present (fear, severe pain, emotional distress, blood phobia, instrumentation) 1, 2
- Typical prodromal symptoms occur, including nausea, diaphoresis (sweating), pallor, lightheadedness, and blurred vision 1, 2, 4
- Loss of consciousness is transient with spontaneous recovery 5
- The patient has no evidence of structural heart disease 1
Important Clinical Distinction
A critical pitfall: When syncope occurs in the supine position in response to pain or fear, it may reflect a more pronounced cardioinhibitory mechanism and warrants more thorough cardiac evaluation, as this presentation is atypical for standard vasovagal syncope. 2 Classical vasovagal syncope typically occurs during standing or sitting, not when lying down. 1
Pathophysiology
The mechanism involves inappropriate reflex activation causing both vasodilation (vasodepressor component) and bradycardia (cardioinhibitory component), leading to systemic hypotension and cerebral hypoperfusion. 1, 2 The relative contribution of each component varies between patients. 4 This reflex is mediated by both sympathetic withdrawal ("vaso...") and parasympathetic activation ("...vagal"), which explains the term "vasovagal." 1