Overview of physiology and pathophysiology of syncope Flashcards Preview

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1

General explanation of syncope?

Specific form of a transient loss of consciousness

2

3 types of syncope?

Reflex
Orthostatic hypotension
Cardiac

3

Sub types of reflex syncope?

Vasovagal (VVS)
Carotid sinus (CCS)
Situational

4

Transient Loss of Consciousness (TLOC) definition?

A state of real or apparent loss of consciousness with loss of awareness, characterized by amnesia for the period of unconsciousness, loss of motor control, loss of responsiveness and a short duration.

5

What conditions can cause TLOC?

Head trauma
Syncope
Epileptic seizures
TLOC mimics (psychogenic, pseudo syncope)
Other causes

6

Definition of syncope?

Transient loss of consciousness due to cerebral hypoperfusion, characterized by rapid onset, short duration and spontaneous complete recovery

7

Reflex syncope?

All types of syncope in which neural reflexes modify HR and/or vascular tone (vasodepression) hence predisposing to a fall in MAP (sysetmic hypotension) of sufficient severity to affect cerebral perfusion causing a transient period of cerebral hypoperfusion resulting syncope or near syncope

8

Reflex syncope is uncommon. True or false?

False. It is common

9

Events that occur in reflex syncope?

When reflex is activated
this causes cardioinhibition through vagal stimulation
causing decreased HR and CO
AND/OR
Vasodepression through depression of sympathetic activity to blood vessels
Decreasing systemic vascular resistance (vasodilation), venous return, stroke volume and CO
This decreases in everything causes decrease in MAP
=
Cerebral hypoperfusion and syncope/ near syncope

10

Most common type of syncope?

Vasovagal

11

What causes vasovagal syncope?

Faint is caused by emotional stress or orthostatic stress

12

What symptoms occur in vasovagal syncope?

Palor
Sweating
Nausea

13

How can vasovagal syncope be averted?

Lying down )adopting horizontal gravity neutralisation)
Leg crossing

Both of these increase venous return

14

Main risk of Vasovagal syncope?

Injury when falling

15

VVS is not associated with increased mortality. True or false?

True

16

Treatment of VVS?

Education
Reassurance
Avoidance of triggers
Adequate hydration

17

What happens in situational syncope?

Faint during or immediately after a specific trigger. Eg coughing, urination, swallowing

18

Vasovagal syncope is less common than situational syncope. True or false?

False. Vasovagal is most common

19

Treatment for situational syncope?

Treat the cause eg if it is a cough
Advise patient to lie down if possible
Avoid dehydration and XS alcohol

However some cases of cardiac pacing may be required in some cases

20

What is the carotid sinus reflex triggered by?

Mechanical manipulation of the neck eg shaving, tight collar

21

Who is CSS more common in?

Elderly males

22

When might CSS occur?

After head and neck surgery or radiation

23

Treatment of carotid sinus syncope?

Permanent pacing is generally recommended

24

Associated conditions with CSS?

Carotid artery atherosclerosis- not clear if this is causative or not

25

Another reason why people have syncope?

Postural hypotension

26

What is postural hypotension?

Results from failure of baroreceptor responses to gravitational shifts in blood, when moving from horizontal to vertical position

27

Other term for postural hypotension?

Orthostatic hypotension

28

Risk factors for orthostatic hypotension?

Age related
Medications
Certain diseases
Reduced intravascular disease
Prolonged bed rest

29

Positive result showing postural hypotension?

Drop in blood pressure within 3 minutes of standing up from lying position
Systolic= Atleast 20mmHg
Diastolic= 10mmHg

30

Symptoms of postural hypotension?

Those of cerebral hypoperfusion- Dizzy, light headed blurred vision, faintness and falls