Syncope

Question 1

What is syncope?

Answer 1

sudden, transient LOC, with rapid + spontaneous recovery thought to be secondary to cerebral hypoperfusion

Question 2

What are the 3 subtypes of syncope?

Answer 2

Cardiac: arrhythmogenic + myocardial
Non-cardiac e.g. Reflex (neurally mediated) + Orthostatic

Question 3

List 6 causes of arrhythmogenic syncope

Answer 3

Sick sinus syndrome
Ventricular tachycardia
AV block
Supraventricular arrhythmias
Adams-Stokes syndrome
Torsades de pointes

Question 4

List 9 causes of myocardial syncope

Answer 4

Massive MI
Aortic stenosis
Mitral valve prolapse
Atherosclerotic cardiovascular diseases
PE
Pulmonary HTN
HOCM
Severe asymmetric septal hypertrophy
Cardiac tamponade

Question 5

List 3 types of reflex syncope

Answer 5

Vasovagal (neurocardiogenic)
Situational
Carotid sinus syndrome

Question 6

List 5 causes of Vasovagal Syncope

Answer 6

Prolonged standing
Emotional stress, e.g. fear, sight of blood
Pain/ injury
Heat exposure
Idiopathic

Question 7

List 5 triggers for situational syncope

Answer 7

Cough
Swallow
Laughing
Defecation
Micturition (common in prostatic hyperplasia)

Question 8

What causes carotid sinus syncope?

Answer 8

Pressure on carotid sinuses (e.g. during a massage, when shaving, tightening a necktie)

Question 9

What is the Vasovagal response?

Answer 9

Hemodynamic response to a trigger (e.g., stress) of the vagus nerve, resulting in a decrease in SNS tone simultaneous with PNS tone increase.
Increased PNS activity results in a drop in HR, BP + heart contractility.
Can lead to fainting (vasovagal syncope).

Question 10

Describe the mechanisms of orthostatic syncope

Answer 10

Mostly orthostatic hypotension
Postural tachycardia syndrome (POTS): orthostasis with tachycardia + no hypotension

Question 11

When does postural tachycardia syndrome often occur?

Answer 11

Following other medical conditions (e.g., pregnancy, trauma, surgery, viral illness)

Question 12

List 6 causes of orthostatic hypotension

Answer 12

Hypovolemia: dehydration, hemorrhage, diuretics, diarrhoea
Meds: BB’s, alpha blockers, CCBs
Neurogenic: Diabetic neuropathy, Parkinson disease

Question 13

What is the most common cause of syncope?

Answer 13

Reflex syncope (all ages)
Orthostatic + cardiac become progressively more common in older patients.

Question 14

List 7 prodromal symptoms of vasovagal syncope

Answer 14

Impairment of senses
Nausea
Pallor
Warmth
Diaphoresis
Lightheadedness
Hyperventilation

Question 15

List 3 prodromal symptoms of orthostatic syncope

Answer 15

Lightheadedness
Nausea
Dizziness

Question 16

How does cardiac syncope often present?

Answer 16

Without any prodrome, i.e. a sudden fall, which may be accompanied by injuries resulting from a lack of protective reflexes.

Question 17

Describe Syncope

Answer 17

Rapid onset LOC
Accompanied by complete loss of muscle tone
Last secs to mins followed by spontaneous recovery

Question 18

What movement can occur in vasovagal syncope?

Answer 18

Brief myoclonus (NOT suggestive of epilepsy)

Question 19

Describe initial evaluation of patients presenting with syncope

Answer 19

Cardio examination
LSBP + HR
ECG for all patients

Question 20

In which circumstances are no further investigations required for syncope?

Answer 20

If typical features, no postural drop + a normal ECG

Question 21

What readings are suggestive of orthostatic syncope?

Answer 21

Symptomatic fall in SBP >20 mmHg
or
DBP >10 mmHg
or
Decrease in SBP < 90mmHg

Question 22

What bloods may be taken in suspected syncope to identify cause of syncope?

Answer 22

Hb: anaemia
U+Es: dehydration
Serum cortisol: adrenal insufficiency
Glucose: DM/ hypoglycaemia
Cardiac enzymes: MI
D-dimer: PE

Question 23

Which investigations are indicated in cardiogenic syncope?

Answer 23

Imaging (e.g. TTE, CTA)
Lab studies (e.g. cardiac enzymes)
Cardiac rhythm monitoring

Question 24

Which investigation can be performed to help confirm noncardiogenic syncope?

Answer 24

Tilt-table test

Question 25

Describe conservative measures for syncope

Answer 25

Increase fluid (2–3L/day) + sodium intake (6–9g salt/day) unless CI
Medication adjustment: discontinue/ decrease dosage of offending/ contributing drugs (e.g., diuretics, antihypertensives).
Instruct patients to avoid/ anticipate triggers.
Advise patients with prodrome to lie down when prodrome is detected (to avoid injuries from falls).

Question 26

Describe management of vasovagal syncope

Answer 26

Conservative Mx
If Sx persist, consider:
Midodrine or fludrocortisone
+/-
Orthostatic training

Question 27

Describe management of situational syncope

Answer 27

Conservative Mx
Avoidance of triggers where possible

Question 28

Describe management of carotid sinus syndrome

Answer 28

Conservative Mx
Avoid triggers, e.g. tight-collared clothing.

Question 29

Describe management of orthostatic syncope

Answer 29

Conservative measures
Compression stockings
Counter-pressure manoeuvres (if prodromal)
Head up tilt sleeping
Consider Midodrine if Sx persist

Question 30

Describe management of cardiogenic syncope

Answer 30

Refer to cardiology
Mx may involve: pacing, anti-arrhythmics, ICD, catheter ablation

Question 31

Give 3 features of autonomic neuropathy in diabetics

Answer 31

1. Postural hypotension
2. Loss of respiratory arrhythmia
3. Erectile dysfunction