Syncope Flashcards
What is syncope?
Syncope is a transient loss of consciousness caused by a temporary reduction in cerebral perfusion, characterised by rapid onset, short duration, and spontaneous recovery.
What are the likely symptoms of syncope?
Symptoms may include dizziness, lightheadedness, nausea, pallor, sweating, and transient loss of consciousness.
What is the primary aetiology of syncope?
It is caused by temporary reductions in blood flow to the brain, often due to cardiovascular, neurogenic, or reflex-mediated mechanisms.
What are common reflex-mediated causes of syncope?
Vasovagal syncope, situational syncope (e.g., during coughing or swallowing), and carotid sinus hypersensitivity.
What are some cardiac causes of syncope?
Arrhythmias, structural heart disease (e.g., aortic stenosis), and cardiomyopathy.
What are some neurological causes of syncope?
Seizures, transient ischaemic attacks (TIA), or stroke, though these are often distinguished as non-syncopal causes of loss of consciousness.
What is the pathophysiology of vasovagal syncope?
It involves an exaggerated response of the parasympathetic nervous system, leading to vasodilation, bradycardia, and reduced cerebral perfusion.
What are the risk factors for syncope?
Advanced age, cardiovascular disease, dehydration, medication use (e.g., antihypertensives), and standing for prolonged periods.
What are common precipitants of vasovagal syncope?
Emotional distress, pain, prolonged standing, and fear.
What key features in history help distinguish syncope from seizures?
Syncope typically has a short prodrome, no post-ictal confusion, and rapid recovery, while seizures often involve tonic-clonic movements and post-ictal confusion.
What investigations are typically performed for syncope?
ECG, blood pressure measurements, blood tests, echocardiography, tilt-table testing, and possibly Holter monitoring or event recorders.
What are common ECG findings in patients with syncope?
Arrhythmias, prolonged QT interval, signs of ischaemia, or evidence of structural heart disease.
What is orthostatic hypotension, and how is it diagnosed?
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.
What are the differential diagnoses for syncope?
Seizures, hypoglycaemia, intoxication, stroke, transient ischaemic attacks (TIA), and psychogenic pseudo-syncope.
What is the role of tilt-table testing in syncope?
It is used to diagnose reflex-mediated syncope by reproducing symptoms under controlled conditions.
What is situational syncope?
Syncope triggered by specific actions such as coughing, swallowing, micturition, or defecation, due to reflex-mediated mechanisms.
What are the management strategies for reflex-mediated syncope?
Education, avoidance of triggers, physical counterpressure manoeuvres, and in some cases, pharmacological therapy or pacemaker insertion.
How is syncope due to orthostatic hypotension managed?
Increased fluid and salt intake, compression stockings, gradual position changes, and review of medications that may exacerbate hypotension.
What is the management of syncope caused by cardiac arrhythmias?
Treatment depends on the underlying arrhythmia and may include antiarrhythmic drugs, pacemaker implantation, or catheter ablation.
What lifestyle advice should be given to a patient with vasovagal syncope?
Avoid prolonged standing, maintain hydration, and recognise prodromal symptoms to sit or lie down before losing consciousness.
What are the red flags in a patient with syncope?
Syncope during exertion, associated chest pain, palpitations, family history of sudden cardiac death, and structural heart disease.
What is carotid sinus hypersensitivity?
An exaggerated response to carotid sinus stimulation, leading to bradycardia, vasodilation, and syncope.
How can dehydration contribute to syncope?
Dehydration reduces intravascular volume, leading to lower blood pressure and cerebral perfusion, increasing the risk of syncope.
What medications can predispose to syncope?
Antihypertensives, diuretics, nitrates, and medications that prolong the QT interval.
