Syncope

Question 1

Define syncope

Answer 1

A transient LoC due to transient global cerebral hypoperfusion characteristic by rapid onset, short duration, and spontaneous complete recovery

Question 2

What are the two general causes of syncope?

Answer 2

Cardiac

CNS

Question 3

Prodromal symptoms suggesting cardiac cause

Answer 3

chest pain
palpitation
dyspnoea

Question 4

Prodromal symptoms suggesting CNS cause

Answer 4

aura
headache
dysarthria
limb weakness

Question 5

What are the classifications of syncope?

Answer 5

Vasovagal syncope (neurocardiogenic)
Situation syncope
Carotid sinus syncope
Stokes-Adams attacks
Orthostatic hypotension

Question 6

What is the underlying cause of vasovagal syncope?

Answer 6

Caused by Reflex bradycardia +/- peripheral vasodilation

Provoked by emotion, pain, fear, or standing too long

Onset over seconds, often preceded by: nausea, pallor, sweating, pre-syncope

Can’t occur if lying down, urinary incontinence uncommon, no tongue biting, rapid recovery

Question 7

Describe the aetiology and characteristics of situation syncope?

Answer 7

Caused by Reflex bradycardia +/- peripheral vasodilation

Cough syncope
Effort syncope (on exercise due to e.g. aortic stenosis)
Micturition syncope

Onset over seconds, often preceded by: nausea, pallor, sweating, pre-syncope

Question 8

Describe the aetiology and characteristics of carotid sinus syncope?

Answer 8

Hypersensitive baroreceptors => excessive reflex bradycardia +/- vasodilation on minimal stimulation

e.g. head turning, shaving

Question 9

What is the underlying cause of Stokes-Adams attacks?

Answer 9

Transient arrhythmias, e.g. bradycardia due to heart block

causes cardiac output to decrease and th. LoC

May happen several times a day in any posture

Question 10

Describe the aetiology and characteristics of orthostatic hypotension?

Answer 10

Decreased BP on standing due to inadequate vasomotor reflexes, due to polypharmacy or autonomic neuropathy