Blackouts or Flashcards
acronym for causes of blackouts
CRASH Cardiac Reflexes Arterial Systemic Head
Cardiac causes of blackouts
Stokes-Adams Attacks
Brady - heart block, sick sinus, long-QT
Tachy - SVT, VT
Structural - weak hear (LVF, tamponade), block (AS, HCM, PE)
Reflex causes of blackouts
- Vagal overactivity
- vasovagal syncope
- situational (cough, effort, micturition) - sympathetic underactivity = postural hypotension
- Salt deficiency (hypovolaemia, Addisons)
- Toxins (Cardiac - ACEi, diuretics, nitrates) (Neuro - TCAs, benzos, antipsychotics, L-DOPA)
- Autonomic Neuropathy (DM, Parkinson’s, GBS)
- Dialysis
- Unwell (chronic bed rest)
- Pooling (venous, varicose veins, prolonged standing)
Acronym for sympathetic underactivity causes of blackouts
STANDUP
arterial causes of blackouts
- Vertebrobasilar insufficiency: migraine, TIA, CVA,
subclavian steal - Shock
- Hypertension: phaeochromocytoma
systemic causes of blackouts
- Metabolic: ↓glucose
- Resp: hypoxia, hypercapnoea (e.g. anxiety)
- Blood: anaemia, hyperviscosity
head causes of blackouts
- epilepsy
- drop attacks
general investigations for blackouts
- lying and standing BP (>20/10 difference after 3 min → postural hypotension)
- ECG ± 24hr ECG
- U+E, FBC, Glucose
- Tilt table
- EEG, sleep EEG
- Echo, CT, MRI brain
Triggers for cardiogenic syncope
exertion, drugs, unknown
symptoms before cardiogenic syncope
palpitations, chest pain, dyspnoea
symptoms during cardiogenic syncope
pale, slow/absent pulse, clonic jerks may occur
symptoms after cardiogenic syncope
rapid recovery
investigations for cardiogenic syncope
- ECG
- 24hr ECG
- Echo
triggers for vasovagal syncope
prolonged standing
heat
fatigue
stress
symptoms before vasovagal syncope or postural hypotension
- Gradual onset: secs→mins
- Nausea, pallor, sweating, tunnel vision, tinnitus
- Cannot occur lying down
symptoms during vasovagal syncope or postural hypotension
- Pale, grey, clammy, brady
- Clonic jerks and incontinence can occur, but no tongue biting
symptoms after vasovagal syncope or postural hypotension
rapid recovery
investigations for vasovagal syncope or postural hypotension
tilt-table testing
triggers for postural hypotension
standing up
triggers for arterial causes of blackout
- arm elevation (subclavian steal)
- migraine
symptoms of arterial blackout
same as vasovagal
+ diplopia, nausea, dysarthria
investigations for arterial blackout
- MRA
- duplex vertebrobasilar circulation
symptoms of hypoglycaemic syncope
tremor, hunger, sweating, lightheadedness
→ LOC
triggers for epileptic causes of blackout
flashing lights
fatigue
fasting
symptoms before epileptic blackout
e.g. aura in complex partial seizures – feeling
strange, epigastric rising, deja/jamias vu, smells, lights,
automatisms
symptoms during epileptic blackout
Tongue biting, incontinence, stiffness→jerking, eyes open, cyanosis, ↓SpO2
symptoms after epileptic blackout
headache,
confusion,
sleeps,
Todd’s palsy
investigations for epileptic blackout
EEG
↑ se prolactin at 10-20min
triggers for drop attacks
nil
symptoms before drop attacks
no warning
symptoms during drop attacks
sudden weakness of legs causes older woman
to fall to the ground.
symptoms after drop attacks
no post-ictal phase
