Approach to Syncope

Differentials

• Cardiac
  • Arrhythmia
  • Aortic stenosis
  • HOCM
• Respiratory
  • Pulmonary embolism
• Neurological
  • Seizure
  • TIA / stroke
    • Tuberous sclerosis
    • Alcohol
    • Drug withdrawal
    • Electrolyte disturbance
    • Lack of sleep
    • Infection
      • Meningitis
      • Encephalitis
    • Scar epilepsy
  • Autonomic dysfunction (DM / Parkinson’s / MSA)
  • Intracranial haemorrhage
  • Brain tumour
• Vasovagal
  • Dehydration
  • Carotid sinus hypersensitivity
  • Micturition syncope
  • Postural hypotension
• Drugs
  • Benzodiazepines
  • Opiates
  • Unintentional overdose
• Endocrine
  • Hypoglycaemia
  • Addison’s
• Symptomatic anaemia
• Vertebro-basilar insufficiency
  • Subclavian steal syndrome
• Anxiety disorder

History

• Syncopal episode
  • Is this the first time this has happened?
  • What were you doing when it happened?
  • Do you remember anything about the event?
  • Did anyone see it happen?
  • Did you notice any odd smells or sounds before it happened?
  • Did you feel light-headed before the attack?
  • Did you feel nauseous or sweaty?
  • Did you feel like you were about to faint?
  • Did you injure yourself when you fell?
  • What about your tongue?
  • Did you wet or soil yourself?
  • Do you remember what happened afterwards?
  • Were you confused?
  • Were you able to get up yourself and call for help?
• Cardiovascular
  • Have you ever experienced a sensation of your heart beating very quickly?
  • Have you ever had any chest pain?
  • Has anyone in your family ever collapsed suddenly?
• Neurological
  • Do you have any birth marks?
  • Have you had any injuries to your head recently?
  • Do you have a headache?
  • Have you noticed any blurred vision?
  • Have you noticed any tingling of your hands or feet?
  • Have you noticed any change in your sense of smell?
  • Have you noticed that it is difficult to get started when you want to do something?
  • Do you find that your movements are unusually slow?
  • Do you take any recreational drugs?
  • Do you drink any alcohol?
  • When was your last drink?
• Situational syncope
  • Does this ever happen when you are passing urine?
  • Do you feel light headed if you turn your head to one side or another?
• Dysautonomia
  • Do you find that you feel light-headed if you get up from a lying or sitting position?
  • Do you feel find that you feel full despite not having eaten much?
  • Has there been any change in your regular bowel motion?
  • Have you found it difficult to pass urine?
• Respiratory
  • Have you noticed any swelling in your legs?
  • Do you use the oral contraceptive pill?
  • Have you been on any long flights recently?
• Endocrine
  • Do you have, or have you ever had diabetes?
  • Are you on any medication for this?
  • Have you noticed that you are excessively thirsty?
  • Do you get up in the middle of the night to pass urine?
  • Have you noticed any change in the colour of your skin?
  • Do you feel unusually tired lately?

Examination

• Vitals
  • Heart rate
  • Blood pressure / postural blood pressure
• Inspection
  • Implantable cardiac device
  • Syndromic facies – e.g. myotonic dystrophy with complete heart block
  • Dermopathic changes consistent with diabetes
  • Skin changes consistent with tuberous sclerosis
  • Tremor
• Pulse: rate, rhythm, volume, character
• Cardiovascular
  • Carotid bruit
  • Apex beat location and character
  • Right ventricular heave
  • Ejection systolic murmur of hypertrophic obstructive cardiomyopathy
  • Ejection systolic murmur of aortic stenosis
• Neurological
  • Pronator drift
  • Extra-ocular movements
  • Bradykinesia
  • Dysmetria
  • Intention tremor

Investigations

• Electrocardiogram
  • Left ventricular hypertrophy
  • Arrhythmia
  • Heart block
• Holter / REKA monitoring if degree of suspicion of arrhythmia is high
• Blood tests
  • Electrolytes – arrhythmia
  • Full blood count – symptomatic anaemia
  • Blood glucose
  • Thyroid function tests
• Electroencephalogram for seizure
• Computed tomography scan of the brain for seizure (structural lesions)
• Drug screen
• Consider tilt table testing

Management

• Patient education: advise not to drive until medically cleared to do so
• Cardiac arrhythmia
  • May require permanent pacemaker if symptomatic heart block
  • May require implantable cardiac defibrillator if malignant arrhythmia
  • May require electrophysiological studies / accessory pathway ablation
• Seizure
  • No need anti-epileptics if this is the first episode and no cause found
  • May recur in the future
  • Pregnancy counselling in women of child-bearing age
• Vasovagal
  • Stay well hydrated
  • Avoid rapid changes in position
• Endocrine
  • Adjust medication to avoid hypoglycaemia
  • Patient education on symptoms of hypoglycaemia and how to avoid it