Simple Faints

Synonyms:

a.k.a. neurally mediated syncope a.k.a. Vasovagal syncope a.k.a. neurocardiogenic syncope a.k.a. vasodepressor syncope:

Clinical features:

Syncope after emotional stimulus
Syncope after Valsalva & Valsalva like: Cough, defaecation, Micturation, Deglutition, Hyperventilation
Syncope after hemodynamic/orthostatic stress e.g. prolonged standing
Preceded by autonomic activation:
Cold sweat: piloerection, sweating & pallor (vasoconstriction)
Nausea & epigastric discomfort (vagal activation)
Blurred vision (papillary vasoconstriction)
Preceded by lightheadedness & darkening of vision

Findings on Investigations:

+Head up tilt-table testing: positive
After tilt up there is a period of normal BP & HR. Then a sudden drop in BP & HR with recurrence of syncopal symptoms. In contrast in autonomic failure: After tilt up there is a progressive gradual drop in BP & HR.
+excluding heart disease +arrhythmia

Treatment:

Reassurance
Avoidance of precipitants
Increase fluid intake to >2L per day
Exercise training:
Training leg muscles
Stand against a wall for up to 40min, twice daily
Physical countermaneuvers:

  • Leg crossing, squating

If recurrent neurocardiogenic syncope, consider:

  • Salt loading
  • Pacemakers are of no benefit [VPSII RCT]
  • Beta blockers are of no benefit [Randomised crossover trial]

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