Cause of syncopes

Reflex (neurological mediation)

  • vasovagal
  • carotid sinus hypersensitivity
  • situational (cough, gasto-intestinal stimulation, micturion, postprandial, post-effort)

Orthostatic

  • primary dysfunction of the autonomic nervous system: Parkinson disease, dementia.
  • secondary dysfunction of the autonomic nervous system: diabetes, amyloïdosis, uremia, vertebral trauma.
  • iatrogenic orthostatic hypotension: alcool, vasodilators, diuretics, antidepressive drugs.
  • volume depletion.

Cardiovascular

  • bradycardia (sick sinus syndrome, AV block, pacemaker dysfunction)
  • tachycardia (supra-ventricular, ventricular)
  • iatrogenic following drug administration (torsades de pointes)
  • structural (obstructive cardiomyopathy, aortic stenosis, cardiac tumor, tamponnade, etc...)
  • pulmonary embolism, aortic dissection.