Syncope.

Front 1

What is syncope

Back 1

Syncope is defined as a transient, self-limited loss of consciousness [1] with an inability to maintain postural tone that is followed by spontaneous recovery

Front 2

What is the pathophysiology of syncope

Back 2

occurs as a consequence of global cerebral hypoperfusion.

Brain parenchyma depends on adequate blood flow to provide a constant supply of glucose, the primary metabolic substrate.

a cessation of cerebral perfusion lasting only 3-5 seconds can result in syncope.

Front 3

What factors help maintain a constant Cerebral perfusion

Back 3

complex feedback system involving

cardiac output (CO),

systemic vascular resistance (SVR)

mean arterial pressure (MAP), intravascular volume status, cerebrovascular resistance with intrinsic autoregulation, and metabolic regulation

Front 4

What can go wrong in those mechanisms

Back 4

CO can be diminished secondary to mechanical outflow obstruction, pump failure, hemodynamically significant arrhythmias, or conduction defects.

SVR can drop secondary to vasomotor instability, autonomic failure, or vasodepressor/vasovagal response.

MAP decreases with all causes of hypovolemia.

Medications can affect CO, SVR, or MAP.

can occur without reduction in cerebral blood flow in patients who have severe metabolic derangements ( hypoglycemia , hyponatremia, hypoxemia, hypercarbia).

Front 5

What are the types of syncope

Back 5

Cardiac

Non cardiac {(reflex (neurally mediated), orthostatic, }

Cardiac syncope is associated with increased mortality, whereas noncardiac syncope is not.

Front 6

Cardiac syncope is associated with increased mortality, whereas noncardiac syncope is not. What are the cardiac causes that need immediate attention

Back 6

vascular disease, cardiomyopathy,

arrhythmia, or

valvular dysfunction they predict a worse short-term and long-term prognosis.

(those with structural heart disease or a history of ventricular arrhythmia.)

Front 7

T

Back 7

G