Syncope

Question 1

What is syncope?

Answer 1

Syncope is a transient loss of consciousness caused by a temporary reduction in cerebral perfusion, characterised by rapid onset, short duration, and spontaneous recovery.

Question 2

What are the likely symptoms of syncope?

Answer 2

Symptoms may include dizziness, lightheadedness, nausea, pallor, sweating, and transient loss of consciousness.

Question 3

What is the primary aetiology of syncope?

Answer 3

It is caused by temporary reductions in blood flow to the brain, often due to cardiovascular, neurogenic, or reflex-mediated mechanisms.

Question 4

What are common reflex-mediated causes of syncope?

Answer 4

Vasovagal syncope, situational syncope (e.g., during coughing or swallowing), and carotid sinus hypersensitivity.

Question 5

What are some cardiac causes of syncope?

Answer 5

Arrhythmias, structural heart disease (e.g., aortic stenosis), and cardiomyopathy.

Question 6

What are some neurological causes of syncope?

Answer 6

Seizures, transient ischaemic attacks (TIA), or stroke, though these are often distinguished as non-syncopal causes of loss of consciousness.

Question 7

What is the pathophysiology of vasovagal syncope?

Answer 7

It involves an exaggerated response of the parasympathetic nervous system, leading to vasodilation, bradycardia, and reduced cerebral perfusion.

Question 8

What are the risk factors for syncope?

Answer 8

Advanced age, cardiovascular disease, dehydration, medication use (e.g., antihypertensives), and standing for prolonged periods.

Question 9

What are common precipitants of vasovagal syncope?

Answer 9

Emotional distress, pain, prolonged standing, and fear.

Question 10

What key features in history help distinguish syncope from seizures?

Answer 10

Syncope typically has a short prodrome, no post-ictal confusion, and rapid recovery, while seizures often involve tonic-clonic movements and post-ictal confusion.

Question 11

What investigations are typically performed for syncope?

Answer 11

ECG, blood pressure measurements, blood tests, echocardiography, tilt-table testing, and possibly Holter monitoring or event recorders.

Question 12

What are common ECG findings in patients with syncope?

Answer 12

Arrhythmias, prolonged QT interval, signs of ischaemia, or evidence of structural heart disease.

Question 13

What is orthostatic hypotension, and how is it diagnosed?

Answer 13

Orthostatic hypotension is a drop in blood pressure upon standing, diagnosed by a decrease in systolic BP ≥ 20 mmHg or diastolic BP ≥ 10 mmHg within 3 minutes of standing.

Question 14

What are the differential diagnoses for syncope?

Answer 14

Seizures, hypoglycaemia, intoxication, stroke, transient ischaemic attacks (TIA), and psychogenic pseudo-syncope.

Question 15

What is the role of tilt-table testing in syncope?

Answer 15

It is used to diagnose reflex-mediated syncope by reproducing symptoms under controlled conditions.

Question 16

What is situational syncope?

Answer 16

Syncope triggered by specific actions such as coughing, swallowing, micturition, or defecation, due to reflex-mediated mechanisms.

Question 17

What are the management strategies for reflex-mediated syncope?

Answer 17

Education, avoidance of triggers, physical counterpressure manoeuvres, and in some cases, pharmacological therapy or pacemaker insertion.

Question 18

How is syncope due to orthostatic hypotension managed?

Answer 18

Increased fluid and salt intake, compression stockings, gradual position changes, and review of medications that may exacerbate hypotension.

Question 19

What is the management of syncope caused by cardiac arrhythmias?

Answer 19

Treatment depends on the underlying arrhythmia and may include antiarrhythmic drugs, pacemaker implantation, or catheter ablation.

Question 20

What lifestyle advice should be given to a patient with vasovagal syncope?

Answer 20

Avoid prolonged standing, maintain hydration, and recognise prodromal symptoms to sit or lie down before losing consciousness.

Question 21

What are the red flags in a patient with syncope?

Answer 21

Syncope during exertion, associated chest pain, palpitations, family history of sudden cardiac death, and structural heart disease.

Question 22

What is carotid sinus hypersensitivity?

Answer 22

An exaggerated response to carotid sinus stimulation, leading to bradycardia, vasodilation, and syncope.

Question 23

How can dehydration contribute to syncope?

Answer 23

Dehydration reduces intravascular volume, leading to lower blood pressure and cerebral perfusion, increasing the risk of syncope.

Question 24

What medications can predispose to syncope?

Answer 24

Antihypertensives, diuretics, nitrates, and medications that prolong the QT interval.

Question 25

Why is distinguishing between syncope and seizures important?

Answer 25

Management differs significantly, as syncope is typically benign, while seizures often require neurological evaluation and anticonvulsant therapy.