Vasovagal Syncope

Background

• Vasovagal syncope is a neurally mediated syncope (also called reflex syncope) often triggered by emotional or orthostatic stress.
  • It is the most common cause of syncope.
  • It makes up about 66% of syncopal episodes presenting to the emergency room.
• Triggers for vasovagal syncope include pain, emotional stress, and fear.

Evaluation

• Initial evaluation includes performing a history, physical, and 12-lead electrocardiogram (ECG) to evaluate for possible underlying structural heart disease .
• Vasovagal syncope highly probable based on history if syncope is triggered by pain, fear, or standing and associated with typical progressive prodrome, such as nausea, diaphoresis, or pale appearance (Strong recommendation).
• Consider tilt testing if the etiology is undetermined after initial evaluation or to confirm diagnosis in patients with suspected neurally mediated syncope (Weak recommendation).

Management

• Treatment goals for vasovagal syncope are aimed at prevention of recurrence and associated injuries and improvement in quality of life through education on awareness and avoidance of triggers.
• Consider nonpharmacologic treatments including:
  • physical counterpressure maneuvers in patients with prodrome (Weak recommendation)
  • promotion of salt and fluid intake unless contraindicated (Weak recommendation)
• Consider the following pharmacological approaches:
  • discontinuing or reducing medications that cause hypotension (Weak recommendation)
  • midodrine in patients with:
    • orthostatic form of vasovagal syncope (Weak recommendation)
    • frequent vasovagal syncope and no hypertension, heart failure, or urinary retention (Weak recommendation)
  • fludrocortisone in patients with
    • recurrent vasovagal syncope and inadequate response to salt and fluid intake if there are no contraindications (Weak recommendation)
    • orthostatic form of vasovagal syncope, low or normal arterial blood pressure, and no contraindication to drug if young age (Weak recommendation)
  • beta blockers are generally not indicated, but may be considered in patients ≥ 42 years old with frequent vasovagal syncope (Weak recommendation)
• Consider implantation of dual-chambered pacemaker to treat patients with frequent episodes of vasovagal syncope that are documented to be cardioinhibitory (Weak recommendation)