From the Guidelines
The workup for near syncope should begin with a thorough history and physical examination, focusing on cardiac, neurological, and orthostatic causes, as recommended by the 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope 1. The initial evaluation should include an electrocardiogram (ECG), orthostatic vital signs, and basic laboratory tests including complete blood count, basic metabolic panel, and cardiac enzymes if cardiac etiology is suspected.
- Key aspects of the history include:
- Precipitating events such as fear, severe pain, emotional distress, instrumentation, or prolonged standing
- Typical prodromal symptoms such as extreme lightheadedness, visual sensations, or altered consciousness
- Symptoms associated with standing, such as lightheadedness, palpitations, or fatigue
- For patients with concerning cardiac features, additional testing may include:
- Echocardiography
- Holter or event monitoring for 24-48 hours
- Exercise stress testing
- If neurological causes are suspected, electroencephalography (EEG) and brain imaging may be appropriate.
- For recurrent unexplained episodes, extended cardiac monitoring with implantable loop recorders for up to 3 years might be necessary, as suggested by the European Heart Journal guidelines 1.
- Tilt table testing can be useful for suspected vasovagal syncope.
- Management depends on the underlying cause, ranging from hydration and salt intake for orthostatic hypotension, to medication adjustments for drug-induced causes, to specific treatments for cardiac arrhythmias.
- Patients with high-risk features such as abnormal ECG, history of heart disease, sudden onset, or syncope during exertion should be considered for hospital admission for further evaluation, as recommended by the guidelines 1.
From the Research
Near Syncope Workup
The workup for near syncope involves a thorough evaluation to determine the underlying cause of the condition. The following steps are typically involved:
- A careful history and physical examination, including orthostatic blood pressure measurements, to identify potential causes of near syncope 2, 3, 4
- Electrocardiographic results to assess for cardiac causes of near syncope 2, 5
- Risk stratification to determine the need for hospital admission or further testing 2, 6, 4
Diagnostic Tests
The following diagnostic tests may be ordered as part of the workup for near syncope:
- Prolonged electrocardiographic monitoring to assess for cardiac arrhythmias 2, 5
- Stress testing and echocardiography to evaluate cardiac function 2
- Neuroimaging to assess for neurologic causes of near syncope, such as head injury or stroke 2
- Laboratory tests, such as hemoglobin measurement, to assess for underlying medical conditions 2
Risk Stratification
Risk stratification tools, such as the Canadian Syncope Risk Score, may be used to determine the risk of adverse outcomes in patients with near syncope 2. Patients with cardiac syncope are at higher risk of adverse outcomes, while those with reflex and orthostatic syncope have a better prognosis 2, 6. The use of decision rules and risk stratification can help guide the disposition of patients with near syncope, with high-risk patients requiring hospital admission and low-risk patients able to be safely discharged 6, 4.