Syncope

Question 1

What is Transient Loss of consciousness (TLOC) ?

Answer 1

A state of real or apparent loss of consciousness, characterized by
-Amnesia for the period of unconsciousness
-Abnormal motor control
-Loss of responsiveness
-Short duration

Question 2

What is syncope ?

Answer 2

TLOC due to cerebral hypoperfusion, characterized by rapid onset, short duration, and spontaneous complete recovery
-generally due to systematic fall in BP

Question 3

What are some causes of TLOC ?

Answer 3

Question 4

What are the main types of syncope ?

Answer 4

Different Types of Syncope:
-Reflex syncope
-Cardiac syncope
-Orthostatic syncope

Question 5

What are risk factors for syncope ?

Answer 5

Question 6

What is reflex syncope ?

Answer 6

Syncope due to failure of normal reflex control of BP and heart rate
-Occurs mainly due to slowing of HR (cardioinhibition), and/or a drop in BP (vasodepression) due to dysfunction of neural reflexes

P. ANS failure rare, S ANS failure due to e.g. antidepressants, antipsychotics, opioids

Question 7

How does reflex syncope work ?

Answer 7

-Vagal stimulation causes cardioinhibition; bradycardia and decreases cardiac output
-Decreased sympathetics; vasodepression, reducution in systemic vascular resistance (also venous pooling)

Reduction in MAP causing cerebral hypoperfusion causing syncope

Bradycardia doesn’t really cause it on its own; if it does a pcemaker is a difinitve treatment

Question 8

What is orthostatic hypotension ?

Answer 8

Sustained reduction of systolic BP of at least 20 mmHg or diastolic BP of 10mmHg within 3min of standing up
-Failure of ANS adjustment/redistirbution of intravscualr volume upon standing from horizontal to vertcal through baroreceptos.

Question 9

What is cardiac syncope ?

Answer 9

Dysfunction of the heart itself causing a reduction in the cardiac output causing reduced cerebral blood flow

Question 10

What are symptoms of reflex syncope and what can trigger it ?

Answer 10

Question 11

What can cause orthostatic syncope ?

Answer 11

-After prolonged standing
-Post-prandial Hypotension (BP drop after eating)
-Starting or changing vasodepressive drugs
-Autonomic neuropathy or parkinsonism

Question 12

What are red flags in cardiac syncope ?

Answer 12

-During exertion or when supine
-Palpitation onset followed by syncope
-Family history of sudden unexplained death at young age
-PMH of structural heart disease or coronary artery disease
-ECG findings significant of arrhythmic syncope

Question 13

What are red flags from history ?

Answer 13

-New onset of chest discomfort, breathlessness, abdominal pain or headache
-Syncope during exertion or when supine
-Sudden onset palpitation followed by syncope
-Association with structural heart disease or abnormal ECG
-No warning symptoms or short (<10s) prodrome
-FH of SCD at young age
-Syncope while seated
-PMH severe structural or coronary artery disease (heart failure, previous MI, known valve disease)

Question 14

What are differential diagnoses of syncope ?

Answer 14

-Falls with out TLOC
-Intracerebral or sub-arachnoid haemorrhage
-TIA
-Generalized/Complex Partial Seizures
-Psychogenic Pseudo Seizures
-Cataplexy
-Metabolic disorders (hypoglycaemia, hypoxia, hyperventilation)
-Intoxication
-Coma
-Cardiac arrest

If arms etc hurt from fall werent unconscious as tried to break fall

Question 15

How can syncope be identified ?

Answer 15

Ofthen has a trigger, short lasting, know quite quickly what happened when they wake up, blue face rare in syncope

Question 16

What are investigations which are used for syncope ?

Answer 16

-Carotid sinus massage to diagnoseCarotid sinus hypersensitivity (a typeof reflex syncope)
-Orthostatic Challenge to diagnoseOrthostatic hypotension
-Basic Autonomic function tests
-Echocardiography for patients with suspected structural heart disease

Question 17

What are some red flags from examination ?

Answer 17

-Unexplained systolic BP in the ED <90 mmHg
-Suggestion of gastrointestinal bleed on rectal examination
-Persistent bradycardia (<40b.p.m) in awake state and in absence of physical training
-Undiagnosed systolic murmur

Question 18

What are some red flags from ECG ?

Answer 18

Question 19

How can diabetic neuropathy complicate MI treatment ?

Answer 19

May not feel MI chest pain but have other symptoms e.g. syncope and feel unwell

Question 20

What are causes of reflex syncope ?

Answer 20

Reflex Syncope
*Vasovagal
*Situational
*Hypersensitive carotid sinus syndrome

Question 21

What are causes of cardiac syncope ?

Answer 21

*Arrhythmia (bradycardia, tachycardia)
*Structural cardiac

Bradycardia doesn’t really cause it on its own; if it does a pcemaker is a difinitve treatment

Question 22

What are causes of orthostatic hypotension ?

Answer 22

Orthostatic Hypotension
-Drug-induced (e.g. GTN); Starting or changing vasodepressive drugs
-Volume depletion (vomiting/diarrhea/bleeding)
-Primary and secondary autonomic failure
-After prolonged standing
-Post-prandial Hypotension (BP drop after eating)
-Autonomic neuropathy or parkinsonism