What is syncope?
Loss of consciousness caused by lack of cerebral blood supply
What are the risk factors for CV syncope?
- 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
What is cardiogenic syncope?
Decrease in cardiac output due to a cardiac arrhythmia or obstructive cardiomyopathy
What can cause cardiogenic syncope?
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
What is arrhythmogenic right ventricular cardiomyopathy?
- RV myocardium replaced with fatty and fibrofatty tissue
* 2nd most common cause of sudden cardiac death in the young after hypertrophic cardiomyopathy
What is sick sinus syndrome?
- Sinus node fibrosis causing the sinus node to become dysfunctional, typically in elderly patients
- Sinus bradycardia or sinus pauses
What are the features of cardiogenic syncope?
- No presyncope symptoms
- Syncope during exercise
What are reflex syncopes and examples?
Abnormal autonomic reflex causes parasympathetic stimulation causing bradycardia +/or hypotension
- Vasovagal syncope
- Micturition syncope
- Cough syncope
- Carotid sinus syncope
What is vasovagal syncope characterised by?
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
What is postural/orthostatic hypotension?
• Peripheral vasoconstriction on standing is impaired
How can you diagnose postural/orthostatic hypotension?
Lying and standing BP
- Drop in BP by >20mmHg
What is long QT syndrome?
o Defect in the slow delayed rectifier potassium channel
o Delayed repolarisation of the ventricular myocardium, QT prolongation and increased risk for syncope
What can long QT syndrome cause?
Can lead to ventricular tachycardia/torsade de pointes
- Risk of sudden cardiac death in the setting of a structurally normal heart
What is Brugada syndrome?
Autosomal dominant
o Mutation in sodium ion channel
What are the DVLA’s rules for syncope?
o If cause identified and treated = 4 weeks
o No cause identified = 6 months
