Common problem in Emergency Medicine, often initially labelled as "collapse ?cause."

Definition of Syncope

Patients who are still unconscious when they are brought into the ED have not had a syncopal episode since their recovery doesn't fit the criteria. They should be evaluated for coma.

Role of the ED in the assessment of syncopal patients

  1. Full diagnostic assessment
  2. Risk stratification and appropriate disposition. Note that patients with syncope of a cardiac origin are at risk of sudden death and must be assessed in detail.
  3. Exclusion of significant injury.
  4. Consideration the patient's occupation and driving status to guide immediate discharge advice

Principal causes of syncope 

Cardiac syncope


Severe orthostatic hypotension


Assessment (and risk assessment )


Physical examination and investigations

Orthostatic hypotension (OH) is an unusual primary cause of syncope. It might be worth looking for in patients who have syncope immediately related to assuming an upright posture. Because the test (using standard BP equipment) has a low sensitivity in detecting OH, it is important to document whether symptoms occur in the absence of BP change.


The majority of patients with syncope will have normal findings on examination and be fully recovered when assessed. However risk stratification, particularly seeking cardiac causes, is crucial to disposition. The patient should fit into one of the categories in the disposal grid below. If in doubt, please seek advice. 

Patients may warrant referral to a Syncope Clinic for diagnostic work-up (EEG, CT, tilt test etc.). Even if you suspect the patient is suffering from simple faints remember there are other proven interventions for those with recurrent vasovagal syncope. 

The incidence of 'simple faints' can be reduced (without referral to a clinic) by advising the patient about avoidance of precipitating situations, maintaining hydration, not getting overheated, and taking avoiding action if warning symptoms appear. Many patients do not realise that lying down can be effective if they feel dizzy. 

Adjusting cardiovascular medications may be helpful, especially in elderly patients who are having giddy spells with postural change and occasional syncope. By reducing the dose of a cardioinhibitory medication, or omitting a vasodilator (depending on whether you think they have symptomatic bradycardia or resting hypotension ), symptom frequency can be reduced. Advise both the patient and GP of any adjustments. If reducing a diuretic or antianginal ensure the patient/carer understands that breathlessness or angina are indications for restarting their 'culprit' medications, and to see their GP.


If you have identified an underlying cause, disposition should be guided by the disposal grid below. 

If the patient is not admitted they should either be referred back to GP, or they can be referred directly toa neurology clinic. The latter option is best for patients in Group 2 below, or those with recurrent symptoms.

Guidelines for disposition from the ED

Disposition Driving restrictions as per UK DVLA guidelines **
1. Simple Faint
Definite provocational factors with associated prodromal symptoms and which are unlikely to occur whilst sitting or lying.
Benign in nature.
If recurrent, will need to check the 3 "Ps" apply on each occasion (provocation / prodrome / postural).
Discharge, if social circumstances favourable

Group I

No driving restrictions

Group II

No driving restrictions

2. Loss of consciousness / loss or altered awareness likely to be unexplained syncope . low risk of re-occurrence.

These patients have no relevant abnormality on CVS and neurological examination, and have a normal ECG.

Refer to GP for follow-up. However, if you feel investigations are warranted refer the patient to Syncope Clinic. See referral form in ED

Group I

Can drive 4 weeks after event.

Group II

Can drive 3 months after event

3. Loss of consciousness / loss or altered awareness likely to be unexplained syncope . high risk of re-occurrence

Factors indicating high risk:

associated chest pain

abnormal ECG

clinical evidence of structural heart disease ( be particularly aware of aortic stenosis )

sudden syncope occurring whilst driving, or whilst sitting / lying, or on exertion.

more than one episode in previous six months.

Admit overnight to the obs unit or under the medical team

Arrange review by the Cardiology team on their post take ward round

Group I

Can drive 4 weeks after the event if the cause has been identified and treated.

If no cause identified, then require 6 months off.

Group II

Can drive after 3 months if cause has been identified and treated.

If no cause found then licence refused/revoked for one year.

4. Unwitnessed (presumed) loss of consciousness / loss or altered awareness with seizure markers

The category is for those where there is a strong clinical suspicion of epilepsy but no definite evidence.

The seizure markers act as indicators and are not absolutes

  • unconsciousness > 5 mins.
  • amnesia > 5 mins
  • injury
  • tongue biting
  • incontinence
  • remain conscious but with confused behaviour
  • headache post attack
Admit medically if suspect new-onset epilepsy, or focal neurology present. The latter group will need urgent neuroimaging ( see the CT guidelines )

If relapse in known epileptic then admission not always indicated, provided the seizure activity represents their normal pattern

Group I

I year refusal/revocation

Group II

5 year refusal/revocation

**Group I; cars, motorcycles, Group II; LGV, HGV etc.

Driving assessment

For patients requesting a formal assessment specifically checking for driving ability, Mr. Sean O' Callaghan (Southern Mobility Assessments 087 9304335) is available for an initial fee of circa €100.

Conditions that can easily be mislabelled as syncope

Disorders with impairment or loss of consciousness

Disorders resembling syncope without LOC

Points to note

Syncope / neurology clinic

To refer a patient write a standard referral letter, preferably typed by the ED secretaries. Include information such as the circumstances of the episode, and ED assessment. A copy of the patient's ECG and any rhythm strips should be enclosed. If relevant request a 24 hour ECG tape prior to the appointment.

Useful reading


DVLA site - await link

Content Dr Ian Higginson 10/06/2003. Reviewed by Dr Íomhar O' Sullivan 08/03/2004, 16/05/2005. Reviewed by Dr Chris Luke 05/11/2005, Dr . ÍOS 28/05/2009. Last review DR. ÍOS 30/08/12