Syncope

Question 1

What is syncope?

Answer 1

Loss of consciousness caused by lack of cerebral blood supply

Question 2

What are the risk factors for CV syncope?

Answer 2

• ECG abnormality
• HF
• TLoC on exertion
• Family Hx of sudden cardiac death <40yrs
• Family Hx of inherited cardiac condition
• New or unexplained breathlessness
• New murmur

Question 3

What is cardiogenic syncope?

Answer 3

Decrease in cardiac output due to a cardiac arrhythmia or obstructive cardiomyopathy

Question 4

What can cause cardiogenic syncope?

Answer 4

Arrhythmias: 
o	Ventricular arrhythmias 
o	AV block
o	WPW syndrome 
o	AF with ventricular involvement
o	Arrhythmogenic right ventricular cardiomyopathy 
o	Sick sinus syndrome

Cardiomyopathy:
o Aortic stenosis
o HOCM
o LV dysfunction

Question 5

What is arrhythmogenic right ventricular cardiomyopathy?

Answer 5

• RV myocardium replaced with fatty and fibrofatty tissue

* 2nd most common cause of sudden cardiac death in the young after hypertrophic cardiomyopathy

Question 6

What is sick sinus syndrome?

Answer 6

• Sinus node fibrosis causing the sinus node to become dysfunctional, typically in elderly patients
• Sinus bradycardia or sinus pauses

Question 7

What are the features of cardiogenic syncope?

Answer 7

• No presyncope symptoms

- Syncope during exercise

Question 8

What are reflex syncopes and examples?

Answer 8

Abnormal autonomic reflex causes parasympathetic stimulation causing bradycardia +/or hypotension

• Vasovagal syncope
• Micturition syncope
• Cough syncope
• Carotid sinus syncope

Question 9

What is vasovagal syncope characterised by?

Answer 9

3 P’s

Posture
- Prolonged standing (syncope after exercise)

Provoking factors
- Pain, medical procedures

Prodromal symptoms

• Pre-syncope (light-headedness)
• Vomiting and nausea
• Hot and sweaty
• ‘closing down’ of vision

May see brief jerking of the limbs

Question 10

What is postural/orthostatic hypotension?

Answer 10

• Peripheral vasoconstriction on standing is impaired

Question 11

How can you diagnose postural/orthostatic hypotension?

Answer 11

Lying and standing BP

- Drop in BP by >20mmHg

Question 12

What is long QT syndrome?

Answer 12

o Defect in the slow delayed rectifier potassium channel

o Delayed repolarisation of the ventricular myocardium, QT prolongation and increased risk for syncope

Question 13

What can long QT syndrome cause?

Answer 13

Can lead to ventricular tachycardia/torsade de pointes

- Risk of sudden cardiac death in the setting of a structurally normal heart

Question 14

What is Brugada syndrome?

Answer 14

Autosomal dominant

o Mutation in sodium ion channel

Question 15

What are the DVLA’s rules for syncope?

Answer 15

o If cause identified and treated = 4 weeks

o No cause identified = 6 months