PPT MADE BY: DR. RAJESH T EAPEN

SPECIALIST – ANESTHESIA ATLAS HOSPITAL

RUWI

What is Syncope?

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

Definition

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

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 consciousness?

• A clouding of vision, diplopia, or vertigo?

• Take a detailed history from the patient and a witness

Epidemiology

• Common in the general population

- 6% of medical admissions

- 3% of Emergency room visits

• Incidence: Male = Female

Risk Factors

• Cardiovascular disease, h/o stroke or TIA & HTN

• Low BMI, ↑alcohol intake & diabetes or elevated blood glucose concentration

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

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

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!

Carotid sinus syncope

• Hypersensitive baroreceptors cause excessive reflex bradycardia ± vasodilatation on minimal stimulation (e.g. head-turning, shaving)

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)

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

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

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 afterwards

• 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)

Other causes • Hypoglycaemia: Tremor, hunger, and

perspiration herald lightheadedness 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.

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

Examination

• Cardiovascular

• Neurological

• BP lying and standing

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

• 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

Treatment – Neurocardiogenic Syncope

• 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

Treatment – Orthostatic hypotension

• 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

Treatment – Cardiovascular (arrhythmia or mechanical):