Vasovagal Syncope

Question 1

Define vasovagal syncope.

Answer 1

Vasovagal syncope occurs when you faint because your body overreacts to certain triggers, such as the sight of blood or extreme emotional distress. It may also be called neurocardiogenic syncope. The vasovagal syncope trigger causes your heart rate and blood pressure to drop suddenly.

Question 2

Explain the aetiology/risk factors of vasovagal syncope.

Answer 2

Prior syncope
Prior history of arrhythmias, myocardial infarction, heart failure, or cardiomyopathy
Severe aortic stenosis
Prolonged standing
Emotional stress (especially in a warm, crowded environment)
Dehydration/hypovolaemia
Preceding episode of nausea and/or vomiting

Question 3

Summarise the epidemiology of vasovagal syncope.

Answer 3

Prevalence of syncope varies in the population:
15% of children (<18 years)
25% of a military population aged 17 to 26 years
16% and 19%, respectively, in men and women aged 40 to 59 years
Up to 23% in a nursing home population aged >70 years.

Question 4

Recognise the presenting symptoms of vasovagal syncope.

Answer 4

Nausea
Lightheadedness
Pallor
Diaphoresis
Diminished vision or hearing
Fatigue after episode

Question 5

Recognise the signs of vasovagal syncope on physical examination.

Answer 5

Palpitations
Bradycardia

Question 6

Identify appropriate investigations for vasovagal syncope and interpret the results.

Answer 6

12-lead ECG
Serum haemoglobin
Plasma blood glucose
Serum beta-human chorionic gonadotropin - rules out syncope caused by the effects of pregnancy
Cardiac enzymes
D-dimer level - rules out pulmonary embolism
Serum cortisol
Urea or serum creatinine