Fit or faint
From Ganfyd
Deciding whether an episode was a fit or a faint is a non-trivial exercise and a practical problem of some frequency and significance.
Witness history
It is useful to obtain a first hand account, preferably by making notes while interviewing the witness shortly afterwards. You need to know the discriminating features and be able to disregard some such as myoclonic seizures which occur in syncope but are often thought to represent epilepsy
Knowledge base
It is also necessary to have a fair knowledge of both neurology and cardiology to diagnose accurately. Most successful litigation has related to the overdiagnosis of epilepsy. You had better know something of syncope and arrhythmias and not make the mistake of sending syncope to a neurologist or other clinician who knows even less cardiology than you do and epilepsy to a cardiologist or other clinician who knows even less neurology than you do.
Believe it or not another extremely rare problem is that it can be a true chicken and egg situation (ie certain forms of epilepsy can induce syncope and visa versa), so the patient might benefit from the true fit or faint specialist. If you have a neurologist who occasionally sends people to have tilt-tables and a cardiologist who occasionally does MRIs of the brain perhaps you are on to a winner with the first specialist you see.
Features Suggestive of Syncope
- New pain, unpleasant sight, sound, smell or situation -vaso-vagal syncope, but if chest pain cardiac syncope/PE
- Long history of syncope
- On standing - orthostatic hypotension
- Relationship to initiation or change of dose in beta blocker, antiarrhythmic, hypotensive agent (includes vasodilators, thalidomide and dopaminergic drugs) or drug that will interact with other such drugs - orthostatic hypotension, cardiac arrhythmias- aortic stenosis
- Standing for prolonged periods- orthostatic hypotension
- Standing in crowded, hot places - vaso-vagal syncope
- Nausea, vomiting associated with syncope - vaso-vagal syncope
- After/during a meal - post prandial syncope
- On head rotation, pressure on neck from tumours, shaving, tight collars - carotid sinus syncope
- After exertion, isometric exercise- arrhythmias/strucural cardiac/situational syncope
- Diabetes with neuropathy or atypical parkinsonism - orthostatic hypotension from autonomic neuropathy
- Palpitations before- arrhythmias
- Family history - vaso vagal syncope
- History sudden death - arrhythmias
- Evidence structural heart disease - cardiac syncope
- Arm exercise - steal syndrome
- ECG evidence of
- Sinus bradycardia (<50 bpm), > 3 second pause, Mobitz type 1 second degree a-v block, sinoatrial block
- Bifascicular block or other intraventricular conduction abnormalities (QRS duration greater than 0.12 s)
- Pre-excitation (delta waves)
- Prolonged QT interval
- Changes suggesting acute myocardial infarction
- Note the above is not exhaustive, but rare conditions such as Brugada syndrome and arrhythmogenic right ventricular dysplasia will have ECGs that meet the above descriptions.
