What is the workup for a female adolescent presenting with fatigue and syncope?

From the Guidelines

The workup for female adolescent fatigue and syncope should begin with a thorough history and physical examination, focusing on the frequency, duration, and circumstances of symptoms, including a detailed medical history, physical examination, family history, and a 12-lead ECG, as recommended by the 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope 1. The initial evaluation should prioritize identifying cardiac causes, given that cardiac syncope represents 1.5% to 6% of pediatric cases, and characteristics of presenting signs and symptoms differentiating vasovagal syncope (VVS) from cardiac causes are generally similar to those in adults 1. Key aspects to consider include:

• The absence of prodromal symptoms
• Presence of preceding palpitations within seconds of loss of consciousness
• Lack of a prolonged upright posture
• Syncope during exercise or in response to auditory or emotional triggers
• Family history of sudden cardiac death (SCD)
• Abnormal physical examination
• Abnormal ECG Initial laboratory tests should include a complete blood count to assess for anemia, comprehensive metabolic panel to evaluate electrolyte abnormalities, thyroid function tests to rule out thyroid disorders, and a pregnancy test. An electrocardiogram (ECG) is essential to identify cardiac causes such as long QT syndrome, arrhythmias, or structural heart disease, and orthostatic vital signs should be measured to detect postural hypotension 1. If cardiac concerns arise from the initial evaluation, noninvasive diagnostic testing, including an echocardiogram and possibly Holter monitoring or event recorder, may be warranted, especially for exertional syncope, which has been associated with long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT) 1. For recurrent syncope, tilt-table testing might be considered, particularly when the diagnosis is unclear, as it can be useful for pediatric patients with suspected VVS 1. Additionally, iron studies, including ferritin levels, are important as iron deficiency is common in adolescent females even without anemia, and vitamin D and B12 levels should be checked as deficiencies can contribute to fatigue. Consider screening for mononucleosis if there are suggestive symptoms, and psychological assessment for depression and anxiety is crucial as these conditions frequently manifest as fatigue in adolescents. Sleep evaluation may be necessary if poor sleep quality is suspected, and management should target the underlying cause, which might include iron supplementation, improved sleep hygiene, or treatment of identified medical conditions. Education on symptom awareness of prodromes and reassurance are indicated in pediatric patients with VVS, and management of children with VVS should include reassurance about the generally benign nature of this condition, emphasizing symptom awareness and avoidance of precipitating factors 1.

From the Research

Evaluation of Female Adolescent Fatigue and Syncope

• The evaluation of syncope in female adolescents involves a careful history, physical examination, and electrocardiography 2, 3.
• Additional testing should be based on the initial clinical evaluation, and may include prolonged electrocardiographic monitoring, echocardiography, and exercise stress testing for patients with underlying organic heart disease or abnormal electrocardiograms 2, 3.
• The primary classifications of syncope are cardiac, reflex (neurogenic), and orthostatic, and evaluation focuses on history, physical examination (including orthostatic blood pressure measurements), and electrocardiographic results 2.

Differential Diagnosis

• Syncope can be classified into four categories: reflex mediated, cardiac, orthostatic, and cerebrovascular 3.
• A cardiac cause of syncope is associated with significantly higher rates of morbidity and mortality than other causes 3.
• The overlap of clinical conditions such as postural orthostatic tachycardia syndrome (POTS), orthostatic hypotension, and neurally mediated syncope (NMS) can lead to confusion regarding syncope classification and pose challenges for diagnosis and treatment, particularly in young women 4.

Diagnostic Approach

• A thorough history taking, complete physical examination, electrocardiography, and further diagnostic work-up as indicated should rule out possible cardiac syncope 5.
• Risk stratification tools, such as the Canadian Syncope Risk Score, may be beneficial in informing decisions regarding hospital admission 2.
• Neuroimaging should be ordered only when findings suggest a neurologic event or a head injury is suspected 2, 3.
• Laboratory tests may be ordered based on history and physical examination findings, such as hemoglobin measurement if gastrointestinal bleeding is suspected 2.