From the Guidelines
The initial workup for a patient presenting with syncope to the ED should include a thorough history, physical examination, and targeted diagnostic testing, prioritizing the identification of life-threatening causes while avoiding unnecessary testing in low-risk patients, as recommended by the most recent guidelines 1.
Initial Evaluation
The initial evaluation of a patient presenting with syncope consists of careful history, physical examination, including orthostatic blood pressure measurements, and standard electrocardiogram (ECG) 1.
- Begin with vital signs, orthostatic measurements, and a 12-lead ECG to identify cardiac causes.
- Obtain a detailed history focusing on circumstances surrounding the event, prodromal symptoms, and past medical history, particularly cardiac conditions.
Diagnostic Testing
Laboratory tests should include complete blood count, basic metabolic panel, cardiac enzymes, and pregnancy test for women of childbearing age.
- Additional testing may include carotid sinus massage in appropriate patients, echocardiogram if structural heart disease is suspected, and continuous cardiac monitoring.
Treatment and Admission Criteria
Treatment depends on the underlying cause:
- Cardiac syncope may require antiarrhythmic medications, pacemaker placement, or ICD implantation;
- Orthostatic hypotension is managed with volume repletion and medication adjustments;
- Vasovagal syncope typically requires education and trigger avoidance. Admission criteria include abnormal ECG findings, history of cardiac disease, significant trauma, persistent abnormal vital signs, or age over 60 with no clear vasovagal trigger, as supported by the guidelines 1.
Rationale
This approach is justified by the need to identify life-threatening causes while avoiding unnecessary testing in low-risk patients, as syncope has diverse etiologies ranging from benign to potentially fatal conditions, and an abnormal initial ECG is predictive of adverse outcomes in patients presenting with syncope and near syncope 1.
From the Research
Initial Workup for Syncope in the ED
The initial workup for a patient presenting with syncope to the emergency department (ED) involves a thorough history, physical examination, and electrocardiographic results 2, 3, 4.
- History: A careful, well-conducted medical history focused on the suspected syncopal event is crucial for the diagnosis 4.
- Physical examination: Including orthostatic blood pressure measurements to assess for orthostatic hypotension 2, 5.
- Electrocardiographic results: A 12-lead electrocardiogram (ECG) is the only instrumental test recommended for the initial evaluation of patients with suspected syncope 4.
Risk Stratification
Patients are designated as having lower or higher risk of adverse outcomes according to history, physical examination, and electrocardiographic results, which can inform decisions regarding hospital admission 2, 6.
- Risk stratification tools: Such as the Canadian Syncope Risk Score, may be beneficial in this decision; some tools include cardiac biomarkers as a component 2.
- Short-term risk assessment: Should be performed to determine the need for admission 5.
Additional Testing
If the findings are inconclusive and indicate possible adverse outcomes, additional testing may be considered 2.
- Prolonged electrocardiographic monitoring, stress testing, and echocardiography: May be beneficial in patients at higher risk of adverse outcomes from cardiac syncope 2.
- Neuroimaging: Should be ordered only when findings suggest a neurologic event or a head injury is suspected 2.
- Laboratory tests: May be ordered based on history and physical examination findings (e.g., hemoglobin measurement if gastrointestinal bleeding is suspected) 2.
- Tilt-table testing: Is appropriate for patients with suspected reflex syncope or orthostatic hypotension 5.
Treatment and Disposition
The prognosis of patients with reflex and orthostatic syncope is good; cardiac syncope is more likely to be associated with adverse outcomes 2.