19 - Syncope

19.1About syncope

Syncope refers to a partial or complete loss of consciousness, usually resulting from a temporary reduction in blood flow to the brain. The onset of syncope is relatively rapid and recovery is generally prompt, spontaneous and complete. The non-medical term for syncope is fainting.

Syncope has many different causes, including cardiovascular disease and neurological disorders.  In some cases, no underlying cause can be found.

The following are the major types of syncope:

  • vasovagal syncope
  • postural syncope, and
  • cardiac syncope.

The most common types of syncope are vasovagal (neurocardiogenic) and cardiac syncope.

Vasovagal syncope

Vasovagal or neurocardiogenic syncope refers to syncope that is triggered by an exaggerated and inappropriate nervous system response to a particular stimulus.  The response is characterized by alterations in heart rate and blood flow, with a subsequent reduction in blood pressure.  The stimulus can be any of a wide range of events such as:

  • dehydration
  • intense emotional stress
  • anxiety
  • fear
  • pain
  • hunger, or
  • the use of alcohol or drugs.

Stimuli can also include forceful coughing, turning of the neck or wearing a tight collar (carotid sinus hypersensitivity), or urinating (micturition syncope).

Postural syncope

Postural syncope is syncope that results from a sudden drop in blood pressure immediately after standing or sitting up.  It can be a side-effect of some medications or may be caused by dehydration or medical conditions such as Parkinson’s disease.

Cardiac syncope

Cardiac syncope refers to syncope caused by cardiac conditions such as:

  • valvular heart disease
  • chronic heart failure, or
  • arrhythmias (bradycardias or tachycardias).

Cardiac arrhythmias are the most common cause of cardiac syncope.

19.2Prevalence

The prevalence of syncope is difficult to determine. One study reported that 3% of males and 3.5% of females had at least one episode of syncope over a 26 year period. The Canadian Cardiovascular Society estimates that syncope may affect as many as 50% of Canadians at some point during their lives. Higher rates of syncope are reported in older individuals.

19.3Syncope and adverse driving outcomes

Few studies have considered the relationship between syncope and driving. Of those that have, most indicate a relationship between syncope and impaired driving performance for at least some groups that experience syncope.

19.4Effect on functional ability to drive

Condition Type of driving impairment and assessment approach Primary functional ability affected Assessment tools
Syncope Episodic impairment: Medical assessment – likelihood of impairment All – sudden incapacitation Medical assessments

Syncope causes an episodic impairment of all the functions necessary for driving.

19.5Compensation

As syncope causes an episodic impairment of the functions necessary for driving, compensation does not apply.

19.6Guideline for Assessment

The following table lists the standards applicable to various types of syncope.

Type of syncope Standards for non-commercial drivers Standards for commercial drivers
Single (one episode within a 12 month period) Typical vasovagal - Typical vasovagal syncope is a vasovagal syncope that occurs when standing and is preceded by warning signs that are sufficient to allow a driver to pull off the road before losing consciousness. 19.6.1 19.6.8
Unexplained 19.6.2 19.6.10
Atypical vasovagal - Atypical vasovagal syncope is a vasovagal syncope that occurs in the sitting position or is not preceded by warning signs that are sufficient to allow a driver to pull off the road before losing consciousness. 19.6.2 19.6.10
Recurrent (two or more episodes within a 12 month period) Reversible cause 19.6.3 19.6.3
Diagnosed and treated cause (e.g. pacemaker for bradycardia) 19.6.4 19.6.9
Typical vasovagal (see definition above) 19.6.5 19.6.10
Situational with an avoidable trigger (e.g. micturition syncope, defecation syncope) 19.6.6 19.6.6
Unexplained 19.6.7 19.6.10
Atypical vasovagal (see definition above) 19.6.7 19.6.10

The following table summarizes the syncope standards and waiting periods

National Standard

Non Commercial Driver

Class 5-8

Commercial Driver

Class 1-4

Single episode of typical vasovagal syncope* No restriction

Diagnosed and treated cause

e.g. permanent pacemaker for bradycardia
1 week 1 month

Reversible cause

e.g. hemorrhage, dehydration
Successful treatment of underlying condition

Situational syncope with avoidable trigger

e.g. micturition syncope, defecation syncope
1 week
  • Single episode of unexplained syncope
  • Recurrent (within 12 months) vasovagal syncope
1 week 12 months
Recurrent episode of unexplained syncope (within 12 months) 3 months 12 months
Syncope due to documented tachyarrhythmia, or inducible tachyarrhythmia at EPS Refer to Cardiac Section on Syncope

(* No restriction is recommended unless the syncope occurs in the sitting position or if it is determined that there may be an insufficient prodrome to pilot the vehicle to the roadside to a stop before losing consciousness. If vasovagal syncope is atypical, the restrictions for “unexplained” syncope apply. EPS: Electrophysiology study)

Rationale for all syncope standards

These guidelines are based primarily on recommendations contained in the final report of the 2003 Canadian Cardiovascular Society (CCS) Consensus Conference Assessment of the Cardiac Patient for Fitness to Drive and Fly.  When applying these standards, the CCS indicates that waiting periods may be modified based on individual factors such as length of any reliable warning symptoms (prodrome), reversible or avoidable precipitating factors, and position from which the individual experiences syncope.

19.6.1 Single episode of typical vasovagal syncope – Non-commercial drivers

Typical vasovagal syncope is a vasovagal syncope that occurs when standing and is preceded by warning signs that are sufficient to allow a driver to pull off the road before losing consciousness.

National Standard Non-commercial drivers eligible for a licence
BC Guidelines RoadSafetyBC will not generally request further information
Conditions for maintaining licence None
Reassessment No re-assessment is required after an episode of typical vasovagal syncope
Information from health care providers Description of the type of syncope
Rationale CCS recommendation

19.6.2 Single episode of unexplained syncope or atypical vasovagal syncope – Non- commercial drivers

Atypical vasovagal syncope is a vasovagal syncope that occurs in the sitting position or is not preceded by warning signs that are sufficient to allow a driver to pull off the road before losing consciousness.

National Standard

Non-commercial drivers eligible for a licence if

  • it has been at least 1 week since the last episode of syncope, and
  • the conditions for maintaining a licence are met
BC Guidelines RoadSafetyBC will not generally request further information
Conditions for maintaining licence Report to the authority and your physician if you have another episode of syncope
Reassessment
  • If an episode of unexplained syncope or atypical vasovagal syncope occurred within the past 12 months, RoadSafetyBC will re-assess in one year
  • If no further episodes are reported at that time, no further re-assessment, other than routine age-related re-assessment is required
Information from health care providers
  • Description of the type of syncope
  • Date of the last episode of syncope
Rationale CCS recommendation. When applying these guidelines, the CCS indicates that waiting periods may be modified based on individual factors such as length of any reliable warning symptoms (prodrome), reversible or avoidable precipitating factors, and position from which the individual experiences syncope

19.6.3 Syncope with a reversible cause

National Standard

All drivers eligible for a licence if

  • the cause has been successfully treated, and
  • the conditions for maintaining a licence are met
BC Guidelines RoadSafetyBC will not generally request further information
Conditions for maintaining licence

RoadSafetyBC will impose the following condition on an individual who is found fit to drive

  • you must report to RoadSafetyBC and your physician if you have another episode of syncope
Reassessment No re-assessment, other than routine age-related re-assessment or routine commercial re-assessment is required, unless re-assessment is required because of the underlying medical condition or treatment
Information from health care providers
  • Description of the cause of the syncope
  • Opinion of the treating physician whether the treatment was successful
Rationale CCS recommendation

19.6.4 Syncope with a diagnosed and treated cause – Non-commercial drivers

Syncope with a diagnosed and treated cause (e.g., pacemaker for bradycardia)

National Standard

Non-commercial drivers eligible for a licence if

  • it has been at least one week since successful treatment, and
  • the conditions for maintaining a licence are met
BC Guidelines RoadSafetyBC will not generally request further information
Conditions for maintaining licence

RoadSafetyBC will impose the following condition on an individual who is found fit to drive

  • you must report to RoadSafetyBC and your physician if you have another episode of syncope
Reassessment No re-assessment, other than routine age-related re-assessment is required, unless re-assessment is required because of the underlying medical condition or treatment
Information from health care providers
  • Description of the cause of the syncope
  • Date of treatment
  • Opinion of the treating physician whether the treatment was successful
Rationale CCS recommendation

19.6.5 Recurrent typical vasovagal syncope – Non-commercial drivers

This guideline applies to non-commercial drivers who have had two or more episodes of typical vasovagal syncope within a 12 month period.

National Standard

Non-commercial drivers eligible for a licence if

  • it has been at least one week since the last episode of syncope
BC Guidelines RoadSafetyBC will not generally request further information
Conditions for maintaining licence No conditions are required
Reassessment
  • For individuals with recurrent typical vasovagal syncope, RoadSafetyBC will re-assess in one year.
  • If no further episodes of syncope are reported at that time, no further re-assessment is required, other than routine age-related re-assessment
Information from health care providers
  • Description of the type of syncope
  • Date of the last episode
Rationale CCS recommendation. When applying these guidelines, the CCS indicates that waiting periods may be modified based on individual factors such as length of any reliable warning symptoms (prodrome), reversible or avoidable precipitating factors, and position from which the individual experiences syncope

19.6.6 Recurrent situational syncope with an avoidable trigger

This guideline applies to drivers who have had two or more episodes of situational syncope with an avoidable trigger (e.g. micturition syncope, defecation syncope) within a 12 month period.

National Standard

All drivers eligible for a licence if

  • it has been at least one week since the last episode of syncope
BC Guidelines RoadSafetyBC will not generally request further information
Conditions for maintaining licence None
Reassessment No re-assessment, other than routine age-related re-assessment is required for individuals with situational syncope.
Information from health care providers
  • Description of the type of syncope
  • Date of the last episode of syncope
Rationale CCS recommendation

19.6.7 Recurrent atypical vasovagal or recurrent unexplained syncope – Non- commercial drivers

This guideline applies to non-commercial drivers who have had two or more episodes of atypical vasovagal syncope, or unexplained syncope within a 12 month period.

Atypical vasovagal syncope is a vasovagal syncope that occurs in the sitting position or is not preceded by warning signs that are sufficient to allow a driver to pull off the road before losing consciousness.

National Standard

Non-commercial drivers eligible for a licence if

  • it has been at least three months since the last episode of syncope, and
  • the conditions for maintaining a licence are met
BC Guidelines

If further information is required, RoadSafetyBC may request

  • a Driver’s Medical Examination Report, or additional information from the treating physician
Conditions for maintaining licence

RoadSafetyBC will impose the following condition on an individual who is found fit to drive

  • you must report to RoadSafetyBC and your physician if you have another episode of syncope
Reassessment
  • RoadSafetyBC will re-assess in one year
  • If no further episodes of syncope are reported at that time, no further re-assessment is required, other than routine age-related re-assessment
Information from health care providers
  • Description of the type of syncope
  • Date of the last episode of syncope
Rationale CCS recommendation. When applying these guidelines, the CCS indicates that waiting periods may be modified based on individual factors such as length of any reliable warning symptoms (prodrome), reversible or avoidable precipitating factors, and position from which the individual experiences syncope

19.6.8 Single episode of typical vasovagal syncope – Commercial drivers

This guideline applies to commercial drivers who have had a single episode of typical vasovagal syncope within a 12 month period.

Typical vasovagal syncope is a vasovagal syncope that occurs when standing and is preceded by warning signs that are sufficient to allow a driver to pull off the road before losing consciousness.

National Standard

Commercial drivers eligible for a licence if

  • the conditions for maintaining a licence are met
BC Guidelines RoadSafetyBC will not generally request further information
Conditions for maintaining licence

RoadSafetyBC will impose the following condition on an individual who is found fit to drive

  • you must report to RoadSafetyBC and your physician if you have another episode of syncope
Reassessment No re-assessment, other than routine commercial re-assessment, is required
Information from health care providers Description of the type of syncope
Rationale CCS recommendation

19.6.9 Syncope with a diagnosed and treated cause – Commercial drivers

This guideline applies to commercial drivers who have syncope with a diagnosed and treated cause (e.g. pacemaker for bradycardia).

National Standard

Commercial drivers eligible for a licence if

  • it has been at least one month since successful treatment, and
  • the conditions for maintaining a licence are met
BC Guidelines RoadSafetyBC will not generally request further information
Conditions for maintaining licence

RoadSafetyBC will impose the following condition on an individual who is found fit to drive

  • you must report to RoadSafetyBC and your physician if you have another episode of syncope
Reassessment No re-assessment, other than routine commercial re-assessment is required, unless re-assessment is required because of the underlying medical condition or treatment
Information from health care providers
  • Description of the cause of the syncope
  • Date of treatment
  • Opinion of the treating physician whether the treatment was successful
Rationale CCS recommendation

19.6.10 Single or recurrent unexplained, single or recurrent atypical vasovagal, or recurrent typical vasovagal syncope – Commercial drivers

This standard applies to commercial drivers who have had:

  • single or recurrent atypical vasovagal syncope
  • single or recurrent unexplained syncope, or
  • recurrent typical vasovagal syncope within a 12 month period.

Typical vasovagal syncope is a vasovagal syncope that occurs when standing and is preceded by warning signs that are sufficient to allow a driver to pull off the road before losing consciousness.

Atypical vasovagal syncope is a vasovagal syncope that occurs in the sitting position or is not preceded by warning signs that are sufficient to allow a driver to pull off the road before losing consciousness.

National Standard

Commercial drivers eligible for a licence if

  • it has been at least 12 months since the last episode of syncope, and
  • the conditions for maintaining a licence are met
BC Guidelines

If further information is required, RoadSafetyBC may request

  • a Driver’s Medical Examination Report, or additional information from the treating physician
Conditions for maintaining licence

RoadSafetyBC will impose the following conditions on an individual who is found fit to drive

  • you must routinely follow your treatment regime and physician’s advice regarding prevention of syncope, and
  • you must report to RoadSafetyBC and your physician if you have another episode of syncope
Reassessment
  • RoadSafetyBC will re-assess in one year.
  • If no further episodes of syncope are reported at that time, no further re-assessment is required, other than routine commercial re-assessment
Information from health care providers
  • Description of the type of syncope
  • Date of the last episode of syncope
  • Opinion of treating physician whether the driver is compliant with the treatment regime and the physician’s advice regarding prevention of syncope
Rationale CCS recommendation. When applying these guidelines, the CCS indicates that waiting periods may be modified based on individual factors such as length of any reliable warning symptoms (prodrome), reversible or avoidable precipitating factors, and position from which the individual experiences syncope