Definition of Syncope and Presyncope

Syncope is a sudden, brief, complete loss of consciousness (LOC) and postural tone caused by global cerebral hypoperfusion. It is followed by spontaneous recovery.  The decreased perfusion to the cerebral cortex or reticular activating system (RAS) leads to the LOC.

Presyncope is a state of lightheadedness, muscular weakness, blurred vision, and feeling faint (as opposed to a syncope, which is actually fainting).

Patients with presyncope have similar prognoses to those with syncope and should undergo a similar evaluation.” AFP 2017.

The 3 Major Classes of Syncope

Syncopes are classified as 1) neurally mediated or reflex syncope, 2) cardiac syncope, and 3) orthostatic hypotension syncope. However, neurologic disease (not truly syncope) often presents as syncope.

syNCOpe

  • Neurally mediated syncope,
  • Cardiogenic syncope,
  • Orthostatic hypotension syncope.

That’s my syncope mnemonic to help you remember all the three major classes of syncope.

“Syncope is classified as neurally mediated, cardiac, and orthostatic hypotension. Neurally mediated syncope is the most common type and has a benign course, whereas cardiac syncope is associated with increased morbidity and mortality. Patients with presyncope have similar prognoses to those with syncope and should undergo a similar evaluation” (AFP 2017).

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