This document discusses syncope, defined as a transient loss of consciousness due to decreased blood flow to the brain. It outlines several common causes of syncope including vasovagal, cardiac arrhythmias, orthostatic hypotension. It emphasizes taking a detailed patient history and physical exam. Common tests include ECG, tilt table test, and echocardiogram. Treatment depends on the underlying cause but may include medications to increase blood pressure, cardiac pacing for arrhythmias, and avoiding triggers.

1. DR. RAJESH T EAPEN
SPECIALIST – ANESTHESIA
ATLAS HOSPITAL
RUWI

2. What is Syncope?
• Common clinical problem and a primary
goal of evaluation is to determine
whether the patient is at increased risk of
death.

3. Definition
• Sudden, self-limited loss of
consciousness in postural tone caused by
transient global cerebral hypoperfusion
& followed by spontaneous complete
and prompt recovery

5. History
• It is vital to establish exactly what
patients mean by 'blackout'
• Do they mean loss of consciousness
(LOC)?
• A fall to the ground without loss of
conscious-ness?
• A clouding of vision, diplopia, or vertigo?
• Take a detailed history from the patient
and a witness

6. Epidemiology
• Common in the general population
- 6% of medical admissions
- 3% of Emergency room visits
• Incidence: Male = Female

8. Risk Factors
• Cardiovascular disease, h/o stroke or TIA
& HTN
• Low BMI, ↑alcohol intake & diabetes or
elevated blood glucose concentration

9. Vasovagal (neuro-cardiogenic)
syncope
• Due to reflex bradycardia ± peripheral
vasodilatation provoked by emotion,
pain, fear or standing too long
• Onset is over seconds (not
instantaneous), and is often preceded
by nausea, pallor, sweating and closing
in of visual fields (pre-syncope)
• It cannot occur if lying down

10. Vasovagal (neuro-cardiogenic)
syncope …..contd.
• The patient falls to the ground, being
unconscious for ~2 min
• Brief clonic jerking of the limbs may occur
(reflex anoxic convulsion due to cerebral
hypo-perfusion), but there is no stiffening
or tonic → clonic sequence
• Urinary incontinence is uncommon (but
can occur), and there is no tongue-biting.
• Post-ictal recovery is rapid

11. Situation syncope
• Syncopal symptoms are as described for
vasovagal syncope
• Cough syncope: Syncope after a paroxysm
of coughing
• Effort syncope: Syncope on exercise;
cardiac origin, e.g. aortic stenosis, HOCM
• Micturition syncope: Syncope during or
after micturition. Mostly men, at night
• Even during swallowing & defecation!

12. Carotid sinus syncope
• Hypersensitive baroreceptors cause
excessive reflex brady-cardia ±
vasodilatation on minimal stimulation
(e.g. head-turning, shaving)

13. Epilepsy
• Attacks vary with the type of seizure,
• Certain features are more suggestive of
epilepsy:
 attacks when asleep or lying down
 aura
 identifiable triggers. e.g. TV
 altered breathing
 cyanosis
 typical tonic-clonic movements
 incontinence of urine
 tongue-biting (ask about a sore tongue after the fit)
 prolonged post-ictal drowsiness, confusion, amnesia and
transient focal paralysis (Todd's palsy)

14. Stokes-Adams attacks
• Transient arrhythmias (e.g. bradycardia
due to complete heart block) causing
↓ cardiac output and LOC
• The patient falls to the ground (often
with no warning except palpitations),
pale, with a slow or absent pulse
• Recovery is in seconds, the patient
flushes, the pulse speeds up, and
consciousness is regained

15. Stokes-Adams attacks …contd.
• Injury is typical of these intermittent
arrhythmias
• As with vasovagal syncope, a few clonic
jerks may occur if an attack is
prolonged, due to cerebral hvpo-
perfusion (reflex anoxic convulsion).
• Attacks may happen several times a day
and in any posture

16. Drop attacks
• Sudden weakness of the legs causes the
patient, usually an older woman, to fall to
the ground
• There is no warning, no LOC and no
confusion after-wards
• The condition is benign, resolving
spontaneously after a number of attacks.
• Other causes: hydrocephalus (these
patients, however. may not be able to get up
for hours); cataplexy-triggered by emotion
(associated with narcolepsy)

17. Other causes
• Hypoglycaemia: Tremor, hunger, and
perspiration herald light-headedness or LOC;
rare in non-diabetics
• Orthostatic hypotension: Unsteadiness or LOC
on standing from lying in those with
inadequate vasomotor reflexes: the elderly;
autonomic neuropathy; antihypertensive
medication; over-diuresis; multi-system
atrophy (MSA)
• Anxiety: Hyperventilation. tremor, sweating.
tachycardia, paraesthesias, light-headedness,
and no LOC suggest a panic attack.

18. Other causes ……….contd.
• Factitious blackouts: pseudo-seizures,
Munchausen's
• Choking: If a large piece of food blocks
the larynx, the patient may collapse,
become cyanotic, and be unable to
speak. Do the Heimlich manoeuvre
immediately to eject the food

19. Examination
• Cardiovascular
• Neurological
• BP lying and standing

20. Investigations
• ECG ± 24h ECG (arrhythmia, long QT, e.g. Romano-
Ward)
• U&E, FBC. glucose
• Tilt-table tests
• EEG, sleep EEG
• Echocardiogram
• CT/MRI brain
• HUT (Head Up Tilt test)
• PaCO2 ↓ in attacks suggest hyperventilation as the
cause
• While the cause is being elucidated, advise against
driving

21. Treatment – Neurocardiogenic Syncope
• Counsel patients to take precautionary steps to
avoid injury by being aware of prodromal
symptoms & maintaining a horizontal position at
those times
• Avoid known precipitants & maintain adequate
hydration
• Employ isometric muscle contractions during
prodrome to abort episode
• Midodrine (start at 5mg PO Tid & can be increased
to 15mg Tid) probably helpful in the treatment
• Cardiac pacing for carotid sinus hypersensitivity is
appropriate in syncopal patients

22. Treatment – Orthostatic hypotension
• Adequate hydration & elimination of
offending drugs
• Salt supplementation, compressive stocking
& counselling on standing slowly
• Midodrine & fludrocortisone can help by
increasing systolic BP & expanding plasma
volume respectively

23. Treatment – Cardiovascular (arrhythmia or
mechanical):
• Treatment of underlying cause(valve replacement,
antiarrhythmic agent, coronary re-vascularisation
etc.)
• Cardiac pacing for sinus node dysfunction or high-
degree AV block
• Discontinuation of QT prolonging drugs
• Catheter ablation procedure in select patients with
syncope associated with SVT
• ICD for documented VT without correctable cause
and for syncope with EF < 35% even in absence of
documented arrhythmia