ED assessment of syncope focuses on differentiating potentially life threatening cardiac syncope from benign causes such as neurocardiogenic (situational, vasovegal syncope) In general if there is reasonable suspicion of a cardiac cause patients should be admitted for work up on telemetry.
Life threatening cardiovascular causes:
Arrhythmia - Brady and tachy
Valvular Dysfunction (Eg: Severe AS)
Myocardial Dysfunction - (ischaemia, cardiomyopathy, myocarditis - poor pump and @ risk of arrhythmia)
Outflow issues - Eg: PE / Dissection
Preload issues (EG: Major haemorrhage - unlikely to present as isolated syncope in a well patient)
Less sinister Causes
Neurocardiogenic -Vasovegal / situational syncope (eg defecation)
Orthostatic -Postural hypotension - think about contributers - meds, dehydration, autonomic dysfunction)
Syncope Mimics - eg seizure, psychogenic
Careful history is the cornerstone of assessment of syncope. Focus on the nature of the syncope, associated symptoms and the risk profile of the patient.
Nature Of Syncope
Unheralded, Seated / lying at time, Exertional
During defecation / urination, preceeded by noxious stimuli (eg: abdominal cramping in gastroenteritis, IV insertion), Positional - orthostatic
Dyspnoea, Chest pain, Palpitations
Preceded by nausea / dizziness.
Risk profile of patient:
Family history of premature cardiac death / cardiomyopathy, Known cardiac disease (esp CCF, Valvular disease, Increasing Age.
Rarely contributory but a focussed cardiovascular exam is important - with attention to murmurs and signs of CCF.
ECG: Most important investigation in syncope.
Know what you are looking for when examining a syncope ECG. The following findings can be subtle and indicate a high risk and warrant admission. Actively exclude them every time you see a syncope ECG). I use the mnemonic ' Can Quick BRAD Walk Home'
Can (Conduction blocks - 2nd degree, 3rd degree, Bifascicular Block)
Quick (QT - long (+ short -rare)
R (RV ischaemia and ischaemic changes in general, esp if associated chest pain)
D (Dilated Cardiomyopathy - non specific ECG findings but may have small voltages)
Other investigations are rarely helpful and should be tailored to the patient, eg FBC in the clinically anaemic patient or those with a history of bleeding) Electrolytes in the dehydrated patient. CXR if associated chest pain.
Risk Stratification tools
Scoring tools exist to attempt to quantify risk in syncope and guide decisions RE admission. (Eg: San Francisco Syncope Rule) Use them with care. (Are you really going to discharge the patient with the family history of sudden cardiac death who presents with exertional syncope just because the SFSR score is 0?)
A great resource for reviewing some of the ECG findings mentioned above.
Emergency Medicine - Cadogan& Brown
Rosens Emergency Medicine