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Syncope

Syncope is defined as a rapid onset of loss of consciousness of short duration as a result of global cerebral hypoperfusion with loss of postural tone, which is followed by spontaneous and complete recovery1.

The goals of assessment in the emergency department are to:

  • Recognise life threatening conditions

  • Determine if it is syncope or not

  • Risk stratify into high risk or low risk and manage accordingly

Life threatening conditions with syncope include pulmonary embolus, cardiac arrythmia, thoracic aortic dissection, ruptured abdominal aorta, ectopic pregnancy and subarachnoid haemorrhage.

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Classification

  1. Neurally mediated (reflex)

  2. Orthostatic hypotension

  3. Cardiac

For a clear and detailed list from the European Society for Cardiology (ESC) please click here.

All patients presenting with syncope require a careful history, physical examination (including orthostatic BP measurements), blood glucose and 12-lead ECG. A normal serum troponin T has a poor negative predictive value for adverse cardiac outcomes following syncope. Click here to view the abstract of the 2005 Hing and Harris study.

Additional examinations (carotid sinus massage, echocardiogram, ECG monitoring or orthostatic challenge), blood tests and imaging are guided by clinical context and disposition.


Risk stratification and management

High Risk episodes:

  • High risk criteria includes severe structural or coronary artery disease, clinical or ECG features suggesting arrhythmic syncope (syncope on exertion or supine, palpitations at the time of syncope, family history of sudden cardiac death or non sustained ventricular tachycardia) and important co-morbidities (including anaemia and electrolyte disturbance).
  • Patients with high risk criteria require prompt hospitalisation or intensive evaluation.

    A clear list produced by the ESC can be accessed here.

Low Risk Episodes:

  • Single or rare episodes: requires no further inviestigations and the patient may be discharged home with GP follow-up.
  • Recurrent episodes: can have delayed further investigations. Patients may be discharged depending on circumstances and following senior ED review.

Syncope rules

Other risk stratification rules may assist in identifying patients at risk. Examples of these are: San Francisco Syncope rule2, OESIL3 score, EGSYS score4 and a study by Martin et al5. The common findings are that abnormal ECG, increased age and history of heart disease imply a worse prognosis at 1 year follow-up.

More information can be found in the "Further resources" section below.


Treatment

Most patients who present with syncope return to normal by the time you assess them.

The goals of treatment are:

  • Prolong survival
  • Limit physical injuries
  • Prevent recurrences

Disposition can at times be challenging and particularly in the low risk recurrent group, despite this group representing patents who may have unknown risk characteristics which are yet to be documented or defined. Inpatient teams are often reluctant to admit them as "subspecialisation" has difficulties with the unknown. These patients should be reviewed by your senior ED doctor prior to discharge (if that is the decision) and a defined follow up should be clearly documented and communicated to the patient and their GP.


Further References and Resources

  1. Moya A, Sutton R. et al .Guidelines for the diagnosis and management of syncope
    (version 2009): the task force for the diagnosis and management of syncope of the
    European Society of Cardiology (ESC). Eur Heart J 2009; 30: 2631-71
  2. Quinn J, McDermott D, Stiell I, Kohn M and Wells G. Prospective validation of the San
    Francisco Syncope Rule to predict patients with serious outcomes. Ann Emerg Med
    2006; 47: 448-454.
  3. Colivicchi F, Ammirati F, Melina D, Guido G, Imperoli G and Santini M. Development and
    prospective validation of a risk stratification system for patients with syncope in the
    emergency department: the OESIL risk score Eur Heart J (2003) 24 (9): 811-819
    doi:10.1016/S0195-668X(02)00827-8
  4. Del Rosso A, Ungar A, Maggi R, Giada F, Petix NR, De Santo T, Menozzi C, Brignole M.
    Clinical predictors of cardiac syncope at initial evaluation in patients referred urgently
    to a general hospital: the EGSYS score. Heart. 2008 Dec;94(12):1620-6. doi:
    10.1136/hrt.2008.143123. Epub 2008 Jun 2
  5. Martin TP, Hanusa BH, Kapoor WN. Risk stratification of patients with syncope. Ann
    Emerg Med 1997;29 (4):459-466.
  6. Morag R Syncope, Medscape, Jun 2012
  7. Strickberger SA, Benson DW, Biaggioni I, Callans DJ, Cohen MI, Ellenbogen KA, Epstein
    AE, Friedman P, Goldberger J, Heidenreich PA, Klein GJ, Knight BP, Morillo CA, Myerburg
    RJ, Sila CA. AHA/ACCF scientific statement on the evaluation of syncope: from the
    American Heart Association Councils on Clinical Cardiology, Cardiovascular Nursing,
    Cardiovascular Disease in the Young, and Stroke, and the Quality of Care and
    Outcomes Research Interdisciplinary Working Group; and the American College of
    Cardiology Foundation in Collaboration With the Heart Rhythm Society. Circulation.
    2006; 113: 316–327
  8. Parry S and Tan M. An approach to the evaluation and management of syncope in
    adults. BMJ 2010;340:c880
  9. Brignole M and Hamdan M. New concepts in the assessment of syncope. J Am Coll
    Cardiol. 2012 May 1;59(18):1583-91. doi: 10.1016/j.jacc.2011.11.056

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