Syncope Flashcards
What is the laymans term for syncope?
fainting
Definition of Transient loss of consciousness
A state of real or apparent loss of consciousness with a loss of awareness, characterised by amnesia for the period of consciousness, loss of motor control . loss of responsiveness and a short duration
Causes of transient loss of consciousness
Head traumatic (traumatic TLOC) Syncope Epileptic seizures (ambiliant) TLOC mimics (e.g. psychogenic pseudo-syncope, psychogenic pseudo- seizures) Other causes
Definition of syncope
Transient loss of consciousness due to celebral hypoperfusion, characterised by rapid onset, short duration and spontaneous complete recovery
What are the 3 categories of syncope?
Reflex Syncope
Orthostatic Hypotension
Cardiac Syncope
What is reflex syncope?
syncope in which neural reflexes modify heart rate (cardioinhibition) and/or vascular tone (vasodepression) hence causing MAP to fall causing systemic hypotension. When of sufficient severity to affect celebral perfusion causing a transient period of celebral hypoperfusion resulting in syncope or near syncope
How is cardioinhibition carried out?
The reflex causes increased vagal stimulation decreasing heart rate (bradycardia) and cardiac output
What are the subtypes of reflex syncope?
Vasovagal Syncope (VVS)
Situational Syncope
Carotid sinus syncope (CSS)
What is the most common type of syncope?
Vasovagal syncope
what triggers vasovagal syncope?
faint triggered by emotional distress (pain, fear, blood pobia etc.) or orthostaatic stress
how is vasodepression carried out
depression of sympathetic activity to blood vessels. This decreases systemic vascular resistance (Vasodilatation), venous return, stroke volume and CO
What are the clinical signs associated with VVS?
typical prodrome (pallor, sweating, nausea)
What can avert VVS if the patient thinks they are going to faint?
adopting a horizontal position (neutralising gravity)
leg crossing
- these increase venous return
What is the main risk associated with VVS?
risk of injury
Treatment of VVS
education
reassurance
avoidance of triggers (if possible)
adequate hydration
What is Situational reflex syncope?
Faint during or immediately after a specific trigger e.g. cough, swallowing etc.
Treatment of Situational reflex syncope
treat the cause if possible advise the patient lie down avoid dehydration avoid excessive alcohol Cardiac permanent pacing - for patients who the fainting is negatively affecting their life and can't be prevented in another way
Carotid Sinus Reflex Syncope
fainting triggered by mechanical manipulation of the neck
what group is most prone to CSS
elderly males
people who have had head and neck surgery or radiation
It is also associated with atherosclerosis in the carotid artery
what is the treatment of CSS?
Cardiac permanent pacing
What is postural (orthostatic) hypotension?
Syncope resulting from failure of Baroreceptor responses to gravitational shifts in blood, when moving from horizontal to vertical position
What are the risk factors for postural hypotension?
Age related Medications Certain diseases Reduced intravascular volume Prolonged bed rest
Positive result for postural hypotension
A drop, within 3 minutes of standing from lying position:
in systolic blood pressure of at least 20 mmHg (with or without symptoms) or
a drop in diastolic blood pressure of at least 10 mm Hg (with symptoms)
What is Cardiac Syncope?
Syncope caused by a cardiac event resulting in a sudden drop in cardicac output
Examples of cardiac events which can cause CSS
Arrythmias - resulting in bradycardia or tachycardia
Acute MI
Structural cardiac disease e.g. aortic stenosis, hypertrophic cardiomyopathy
Other CV disease e.g PE, aortic dissection
Factors which indicate Cardiac Syncope
Syncope when supine
Syncope during excretion
Presence of a structural cardiac abnormality or CHD
Family history of sudden death at young age
Sudden onset of palpitations immediately followed by syncope
ECG suggesting arrhythmic syncope
