From the Guidelines
The initial workup for presyncope triggered by visual stimuli in an 18-year-old female should begin with a thorough history and physical examination, including orthostatic vital signs, cardiac and neurological assessment, followed by a 12-lead ECG, basic laboratory tests, and an echocardiogram, with consideration of a tilt-table test to evaluate for vasovagal syncope, as recommended by the 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope 1. The differential diagnosis for presyncope triggered by visual stimuli in this patient includes:
- Vasovagal syncope
- Orthostatic hypotension
- Cardiac arrhythmias
- Structural heart disease
- Seizure disorders
- Psychiatric conditions Initial evaluation should focus on identifying potential causes and risk factors, including:
- Family history of cardiac conditions or sudden death
- Medication use
- Associated symptoms, such as palpitations or chest pain
- Triggers, such as emotional stress or loud noises Given the visual trigger, vasovagal syncope is a likely diagnosis, and a tilt-table test may be useful in evaluating this condition, as suggested by the 2017 ACC/AHA/HRS guideline 1. However, the ACR Appropriateness Criteria for syncope also recommend a more conservative approach, with initial evaluation focusing on history, physical examination, and basic laboratory tests, reserving further testing, such as tilt-table testing, for patients with unclear diagnosis or high-risk features 1. In patients with suspected vasovagal syncope, management may include education on trigger avoidance, proper hydration, increased salt intake, and physical counterpressure maneuvers, with beta-blockers considered for recurrent symptoms, as recommended by the European Heart Journal guidelines for the diagnosis and management of syncope 1. Referral to cardiology or neurology may be necessary depending on initial findings, and further testing, such as EEG or advanced cardiac imaging, may be warranted if seizure activity or structural heart disease is suspected.
From the Research
Differential Diagnosis for Presyncope
The differential diagnosis for presyncope triggered by visual stimuli in an 18-year-old female includes:
- Neurally mediated syncope (NMS) 2, 3
- Orthostatic hypotension 2, 3
- Postural orthostatic tachycardia syndrome (POTS) 3
- Cardiac syncope 2
- Vasovagal syncope (VVS) 4
Initial Workup
The initial workup for presyncope includes:
- Detailed history 2
- Physical examination 2
- Electrocardiography (ECG) 2
- Laboratory testing and neuroimaging may be ordered if clinically indicated, but have a low diagnostic yield 2
- Consideration of anxiety and depression as potential risk factors for VVS and treatment targets 4
Considerations for Young Women
In young women, it is essential to maintain a broad differential diagnosis when considering the diagnosis of NMS, as more sinister diagnoses may be overlooked 3. The importance of considering NMS as a diagnosis of exclusion cannot be overstated 3.
Risk Stratification
Low-risk patients with a single episode of presyncope can often be reassured with no further investigation, while high-risk patients with cardiovascular or structural heart disease, history concerning for arrhythmia, abnormal ECG findings, or severe comorbidities should be admitted to the hospital for further evaluation 2.