Approach to syncope Flashcards
What is the definition of syncope?
A sudden transient total loss of consciousness and postural tone resulting from global cerebral hypoperfusion with spontaneous and complete recovery without neurological sequelae
What is the red flag neurological symptoms to be screened for in a patient with syncope (Sheldon criteria for seizure vs syncope) ?
- Tongue biting
- Head turning to one side during syncope
- Unresponsive
- Unusual posturing
- Prolonged limb jerking (brief seizure-loke activity can often occur in uncomplicated faints)
- Confusion following events
- No memory of abnormal behaviour that was witnessed before, during or after syncope, by someone else
- Prodromal déjà vu or jamais vu
What are the red flags to suggest cardiac syncope?
- Syncope on exertion: Suggests insufficient cardiac output under the demands of exertion, or unproved arrhythmia
- Syncope when supine (inconsistent with vasovagal syncope or postural hypotension)
- Sudden syncope without warning (prodrome of light headedness is expected in vasovagal syncope)
- Chest pain or palpitations at time of syncope
- Known cardiac disease including pacemakers
- Family history of sudden cardiac death, age < 40 years old and/ or inherited cardiac condition
- New/ unexplained breathlessness
- Abnormal cardiac exam including murmur and fluid overload.
What are the different causes of syncope?
1) Cardiogenic syncope
2) Neurogenic syncope
- Vasovagal syncope
- Situational syncope
3) Postural hypotension
4) Cerebrovascular (Vascular steal syndrome)
[Contextual features to differentiate between neurally mediated syncope, postural hypotension, cardiovascular syncope and seizure]
Neurally mediated syncope
- Prolonged _______________
- Absence of _______________
- Long history recurrent syncope
- After exertion
- During a meal or post prandial
- With head rotation or pressure on carotid sinus (tight collars, shaving)
- During immediately after defecation, micturition, cough, swallowing
Othostatic hypotension
- Prolonged standing in hot, crowded places
- ___________ after exertion
- Temporal relationship with start or changes of ______________, leading to hypotension
Cardiovascular
- exertion, palpitations, chest pain
- If CVS: Presence of definite structural heart disease
Seizure
- Head injury, structural brain disease
- Infection, metabolic disturbances
- ____, ______, _____, ____
- Prior seizures
standing, heat, emotions, crowds;
heart disease history;
Standing up;
vasodepressive drugs;
Sleep deprivation, alcohol, bright lights (triggers). aura
What are the pre event features to differentiate between neurally mediated syncope, postural hypotension, cardiovascular syncope and seizure?
Neurally mediate syncope
- Usually a prodrome of light headedness, fading of vision, pallor, diaphoresis, cold sweat, N&V, dull hearing/ BOV, palpitations, pallor, chest pain, dyspnoea
Postural hypotension: Symptoms with upright posture
Cardiovascular
- Chest pain
- Giddiness
- Diaphoresis
- Sudden onset palpitation immediately followed by syncope
Seizure
- May have aura e.g. unusual smell / taste (temporal); sensation (parietal); see stars / numbers / dots (occipital), ear fullness, rising sensation in abdomen, déjà vu
- May be sudden, without warning
What are the during event features to differentiate between syncope and seizure?
Syncope
- hypotension or bradycardia (if observed)
- brief motor activity, including clonic jerks due to hypoxic fit
- brief (1-15s)
Seizures
- sustained tonic clonic or myoclonic movements
- automatisms or blank staring
- lateral tongue biting
- Clear automatism (lip-smacking)
- forceful head turn to one side (versions)
- Prolonged (>30s- 2min)
- Urine incontinence common
- Peripheral tongue bite common
What are the post event features to differentiate between syncope and seizure?
Syncope
- Pallor, diaphoresis, flushing
- Rapid, complete recovery to full alertness
Seizure
- Post ictal drowsiness (especially generalised seizures)
- May have transient weakness (Todd’s paralysis)
- Nose wiping in focal seizure
What are the cardiac causes of syncope?
Structural heart disease
- Critical aortic stenosis
- Hypertrophic obstructive cardiomyopathy
- Pulmonary stenosis, pulmonary embolism, pulmonary hypertension
- Heart failure
- Artic dissection
Arrhythmias
- Sinus dysfunction e.g. sick sinus syndrome
- High grade atrioventricular block
- Ventricular tachycardia
- Pacemaker malfunction
Channelopathies
- Long QT syndrome: congenital or acquired (e.g. drugs, antipsychotics, fluoroquinolones)
- Brugada syndrome
- Wolff- Parkinson- White syndrome
What is the definition of postural hypotension?
Sustained reduction in systolic blood pressure > 20 mmHg or diastolic pressure >10mmHg
What are the causes of postural hypotension?
- Volume depletion: vomiting, diarrhoea, hyperglycemia poor fluid intake
- drugs: TCAs, beta blockers
- adrenal insufficiency
- autonomic failure with peripheral neuropathy: long standing diabetes, metabolic (vitamin B12 deficiency, toxins), paraneoplastic, infective (HIV), inflammatory (sjogren, guillain barre syndrome), infiltrative (amyloidosis), hereditary sensory and autonomic failure
- autonomic failure associated with parkinsonism, ataxia or dementia: multiple system atrophy, parkinson disease, dementia with lewy bodies
What are the causes of a neurogenic syncope? What are the classical textbook description of these causes?
Vasovagal syncope:
- Young healthy person who loses consciousness while upright, when faced with orthostatic stress (prolonged standing, dehydration, hot weather, after physical exertion) or emotional stimuli (e.g. crowded environment, noxious stimuli)
- Prodrome of light headedness, sweating, nausea, gradual darkening or blurring of vision
- Supine position rapidly restores cerebral blood flow, patient rapidly and completely regains alertness although there may be some residual fatigue and pallor
Situational syncope refers to syncope associated with particular actions e.g. micturition, cough, defecation, swallowing, or carotid sinus massage
History: Triggers to ask for before loss of consciousness in a patient with syncope
- Cardiac (HCM, Aortic Stenosis, Heart Block): ___________, Chest pain, palpitations, dyspnoea, diaphoresis
- Vasovagal: Pain or anxiety, prolonged standing, sight of blood/needles
- Postural HypoTN: Upon ______________
- Vertebrobasilar attacks: _________________
- Pulmonary embolism: __________________
Exertional;
Standing;
Neck movements;
Prolonged travel, bed rest, recent surgery, recurrent miscarriage, HRT/OCP, Cancers, pregnancy
What are the causes of syncope that causes loss of consciousness immediately without prodrome / warning?
- Stokes Adams attack
- ARRHYTHMIA
What are the symptoms to ask for right before loss of consciousness in a patient with syncope + to differentiate from seizure?
- Syncope Prodrome of: light-headedness, cold sweat, N&V, dull hearing /BOV, visual tunnelling
- Seizure Aura of: rising sensation from abdomen, abnormal sights / smell / taste, sees lines / dots, ear fullness
