Syncope Flashcards
What is syncope?
Decreased blood supply to brain causing loss of consciousness - transient, self-terminating,inadequate nutrient flow to brain. May have pro formal syndrome (hypoperfusion to brain)
Common types of syncope
Neurocardiogenic syncope
Carotid sinus hypersensitivity
Orthostatic syncope
Medication related syncope
Examples of neurocardiogenic syncope
Micturition
Defecation
Cough mediated
Degluttition
Glossopharyngeal nerve
Situational
What can cause carotid sinus hypersensitivity?
Head turning
Circumferential neck compression - neck tie
Shaving
What causes orthostatic syncope?
Volume loss
Autonomic dysfinction
Deconditioning, prolonged bed rest
What groups of meds can cause syncope>
Vaso active
Meds affecting conduction - antiarrhythmics, CCBs, Beta blockers, digoxin
Meds affecting QT interval
Diuretics
What meds affect the QT interval?
Antiarrhythmics
Antiemetics
Antipsychotics/depressants
What medications are vasoactive?
Alpha and beta blockers, CCBs, nitrates, anithypertensive medications, diuretucs, erectile dysfunction meds
Other common causes of syncope
- Lack of blood/oxygen
- Accidental fall
- Narcolepsy
- Psychogenic pseudosyncope
- Psychogenic non epileptic seizure
- Cardiac arrest
What to check in a syncope history?
- Context
- Prodrome
- Duration
- Recovery
- Frequency
Did LOC happen before or after fall?
Amnesia around fall?
Long lie?
Transient LOC or unresponsive?
Collateral history?
What could cause a responsive syncope?
- Syncope
- Generalised seizure
- Stroke
- psychogenic pseudosyncope
- Psychogenic no epileptic seizure
Causes of unresponsive syncope?
- Toxic metabolic causes
- Status epilepticus
- Psychogenic of above
- Stroke
What conditions are not technically syncope but should be considered in initial history?
- Seizure
- Stroke
- Head injury
- Cardaic syncope
- Blood loss
- PE
- Subarrachnoid haemorrhage
High risk factors of onset of syncope
During exertion
In supine position
New onset chest discomfort
Palpitations before syncope
Ass with dyspnoea
High risk factors in medical history with syncope?
FH sudden death
Decompensated/congestive HF
Aortic stenosis
LV outflow tract disease
Dilated cardiomyopahty
Hypertrophic cardiomyopathy
Arrhythmogenic RV cardiomyopathy
LV ejection fraction <35%
Documented Ventricular arrythmia
Coronary artery disease
Congenital HD
Pulmonary HPTN
ICD implantation
High risk symptoms, signs or variables ass with syncopal episode
Anaemia - Hb < 9g/dL
Lowest systolic BP in emergency department <90mmHg
Sinus bradycardia < 40bpm
High risk ECG ffeatures with syncope
New or prev undiagnosed LBBB N
Bifascicular block + first degree AV block
Brugada ECG pattern
ECG changes consitent with acute ischaemia
Non sinus rhythm thats new
Bifascicular block
Prolonged QTc >450ms
Causes of VT
Channelopathies (Na+ and K+)
WPW
QT prolongation
Electrolyte disturbances
Hypothermia
Structural HD
How is VT defined on ECG?
3 or more ventricular atopic beats at a rate of < 130bpm
if > 30s = sustained
What is seen on ECG in RBBB?
MaRroW
‘W’ pattern in V1
Widened S spaces
QRS > 120ms
Dominant S wave in V1
Broad R wave, absence of Q waves in lateral leads
Prolonged R wave peak time > 60ms in V5-6
What is torsades de pointes?
V fast ventricular - polymorphic tachycardia
Treat with magnesium, implantable device
What causes Torsades de pointes?
Prolonged QT syndrome
Medications: Antifungals.
Antibiotics.
Antipsychotics.
Antiemetics (for nausea and vomiting).
Antiarrhythmics.
Cancer medicines.
Life threatening causes of syncope
MI
Cardiac arrhytmia
PE - massive
Occult haemorrhage
Arotic dissection
Cardiac tamponade
Severe hypoglycaemia
Major intracranial event
What does a massive PE on ECG?
RBBB
Extreme R axis deviation
S1Q3T3
T-wave inversions in V1-4 + lead III
Clockwise rotation with persistent S wave in V6
What is bifascicular block adn first egree AV block on ECG?
RBBB
LAD
1st degree AV block
Causes RBBB
Right ventricular hypertrophy/cor pulmonale
PE
IHD
Rheumatic heart disease
Congenital HD
Myocarditis
Lenegre Lev disease - primary degenerative disease/fibrosis of conducting system
What is brugada syndrome and what does it look like on ECG?
Hereditary channelopathy causing syncope, VT, VF, cardiac arrest, sudden death
ST elevation in V1-3
VF on ECG
Dx of VF
Chaotic irregular deflections of varying amplitude
No identifiable P waves, QRS complexes or T waves
Rate 150 to 500 BPM
Amplitude decreases with duration
Structural heart abnormalities causing syncope
- Valvular heart disease: aortic stenosis, mitral stenosis
- Cardiomyopathy - ischaemic, dilated, hypertrophic
- Atrial myxoma
- Cardiac tampon are
- Aortic dissection
3 Ps of vasovagal
Posture - blackout occured after prolonged standing
Provoking factors - pain or medical procedure
Prodromal symptoms - sweating or feeling warm/hot before the blackout occured
How to diagnose vasovagal syncope
Postural BO falls by 20 systolic or 10 diastolic
ECG for QT changes
Diagnosis of orthostatic syncope
Lying standing BP -> Fall in systolic BP of at least 20 mmHG at least 30 if have HPTN and or fall of diastolic - 10 mmhg within 3 mins of standing
Management of orthostatic syncope
Reduce polypharmacy
Graded pressure stockings
Fluorocortisone can help but cause increase BP
Causes of orthostatic syncope
- Old age
- Parkinsons
- Diabetic autonomic neuropahty
- Lewy Body dementia
- Volume loss
- Autonomic dysfunction
- deconditioning, prolonged bed rest
- Drugs that ower HR, BP
How can parkinsons cause syncope
Autonomic dysfunction prone ot
Examples of pseudosyncope
Epilepsy - seizure
Hypoglycaemia
Drug overdose
Investigations syncope
Check relevance
Bloods
ECG
CXR
CT head if injured or indicated
What is seen on ECG in LBBB?
Prolonged QRS complexes
W in Lead I - positive waves
M in lead 6 - negative waves
WiLliam
R bundle branch block on ECG? What is it seen in?
M in Lead I - positive
W in lead 6 - negative
PE, S1Q3T3 pattern
MaRroW
What counts as a widened QRS?
> 120ms - 3 small swuares
What to ask about before and after syncope?
Prodrmie - aura, dizzy, sweat, blurred vision
After - memory, recovery time, post-ictal phase, injury
