From the Guidelines
The outpatient workup for syncope should begin with a thorough history and physical examination, focusing on the circumstances surrounding the event, prodromal symptoms, and any associated features, as recommended by the European Heart Journal guidelines 1. The initial evaluation should include orthostatic vital signs, a 12-lead ECG, and basic laboratory tests (complete blood count, basic metabolic panel, and cardiac enzymes if recent) to identify potential causes of syncope, such as orthostatic hypotension, cardiac arrhythmias, or metabolic disorders 1. For patients with suspected cardiac syncope, additional testing may include:
- Ambulatory cardiac monitoring (24-hour Holter monitor for frequent episodes or 30-day event recorder for infrequent episodes) to detect arrhythmias 1
- Echocardiography to assess structural heart disease 1
- Exercise stress testing if exertional syncope is reported 1 Tilt-table testing may be useful for suspected vasovagal syncope, particularly in recurrent cases without clear triggers, as recommended by the American Heart Association councils on clinical cardiology, cardiovascular nursing, cardiovascular disease in the young, and stroke 1. Carotid sinus massage can be considered in older patients with unexplained syncope, but should be avoided in those with carotid bruits or history of stroke, as it may precipitate a stroke or worsen existing carotid artery disease 1. Neurological evaluation, including EEG or brain imaging, is generally not recommended unless there are specific neurological symptoms or signs, such as focal neurological deficits or a history of head trauma, as these may indicate a neurological origin of syncope 1. Specialized cardiac testing, such as electrophysiology studies, should be reserved for patients with structural heart disease or abnormal ECG findings, as these may indicate a high risk of cardiac arrhythmias or sudden cardiac death 1. The workup should be tailored to the patient's risk factors, with more extensive evaluation for those with heart disease, abnormal ECG, older age, or no prodromal symptoms, as these factors suggest higher risk of cardiac causes, and a careful physical examination is second only to the history in identifying potential causes of syncope 1.
From the Research
Outpatient Workup for Syncope
The outpatient workup for syncope involves a thorough evaluation to determine the underlying cause of the condition. The following steps are typically taken:
- History-taking: A careful medical history is crucial for making the diagnosis, as it helps to identify the suspected cause of syncope 2.
- Physical examination: A physical examination, including orthostatic assessment, is essential for evaluating patients with syncope 3, 2.
- Electrocardiogram (ECG): A 12-lead ECG is the only instrumental test recommended for the initial evaluation of patients with suspected syncope, as it may disclose an arrhythmia associated with a high likelihood of syncope 4.
- Risk stratification: Short-term risk assessment should be performed to determine the need for admission or outpatient evaluation 2.
- Additional testing: If the findings are inconclusive and indicate possible adverse outcomes, additional testing such as prolonged electrocardiographic monitoring, stress testing, and echocardiography may be considered, especially in patients with cardiac syncope 3.
- Tilt-table testing: In patients with suspected reflex syncope or orthostatic hypotension, outpatient evaluation with tilt-table testing is appropriate 2.
- Laboratory tests: Laboratory tests may be ordered based on history and physical examination findings, such as hemoglobin measurement if gastrointestinal bleeding is suspected 3.
- Referral to a specialist: If heart disease is found to be the cause of the syncope, a specialist opinion is warranted, and where possible, the problem should be corrected 5.