Syncope in Adults Flashcards
Define syncope
Transient loss of consciousness with full recovery
List 4 disorders with partial or complete LOC but without cerebral hypoperfusion, and which are often mistaken for syncope
Epilepsy
Metabolic disorders (e.g. hypoglycaemia, hypoxia, hyperventilation with hypocapnia)
Intoxication
Vertebrobasilar TIA (most other TIAs do not result in LOC)
List 4 disorders without impairment of consciousness which are often mistaken for syncope
Cataplexy Drop attacks Falls Functional (psychogenic pseudosyncope) TIA of carotid origin
What is the most common cause of syncope?
Reflex/neurocardiogenic
What is the 2nd most common cause of syncope?
Orthostatic hypotension
What is the least common cause of syncope?
Cardiac
What are the 4 classes of reflex syncope and what are the precipitating factors for each?
Vasovagal: emotional distress, orthostatic stress
Situational: cough, GI stimulation, micturition, post-exercise, post-prandial
Carotid sinus syncope: pressure on carotid sinus (e.g. tight collar, sharp turn of neck)
Atypical forms: no apparent triggers (or an atypical presentation)
What are 4 underlying causes of syncope due to orthostatic hypotension?
Primary autonomic failure
Secondary autonomic failure
Drug-induced
Volume depletion
What are 3 underlying causes of cardiac syncope?
Arrhythmia as primary cause
Drug-induced bradycardia and tachyarrhythmias
Structural disease
Give 4 examples of drugs which may induce bradycardia
B-blockers
Antiarrhythmics
Ca2+ channel blockers
Drugs for dementia
What kind of 2nd degree heart block is an indication for pacing?
Mobitz II
Obstructive cardiomyopathy
Subaortic obstruction
Post-exertional syncope classically
What clinical test should be used in suspected orthostatic hypotension?
Lying-to-standing BP
List 10 clinical or ECG features suggesting arrhythmic syncope
Syncope during exercise or spine
Palpitations at the time of syncope
FHx of SCD
Non-sustained VT
Bifascicular block
Inadequate sinus bradycardia or SA block in absence of negative chronotropic Rx or physical training
Pre-excited QRS complex
Prolonged or short QT interval
RBBB pattern with ST elevation in leads V1-V3
Negative T waves in R praecordial leads, epsilon waves and ventricular late potentials suggestive of ARVC
What drugs can produce a prolonged QT interval?
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