What laboratory tests are indicated for a female adolescent presenting with fatigue and syncope?

From the Guidelines

For an adolescent female presenting with fatigue and syncope, I recommend ordering a complete blood count (CBC), comprehensive metabolic panel (CMP), thyroid function tests (TSH, free T4), iron studies (ferritin, iron, TIBC), vitamin B12 and folate levels, electrocardiogram (ECG), and orthostatic vital signs. Additional tests to consider include hemoglobin A1c, pregnancy test, urinalysis, and an electroencephalogram (EEG) if seizures are suspected. Anemia is a common cause of fatigue and syncope in adolescent females due to menstrual blood loss, so iron studies are particularly important 1. Thyroid dysfunction can cause fatigue, while electrolyte abnormalities detected on CMP may contribute to syncope. Cardiac causes should be ruled out with an ECG, as conditions like long QT syndrome can cause syncope in young people 1. Orthostatic hypotension is another common cause of syncope that can be detected with orthostatic vital signs. If initial testing is unrevealing and symptoms persist, consider referral to appropriate specialists such as cardiology, neurology, or endocrinology for further evaluation. The selection of diagnostic tests should be based on the patient’s clinical presentation, risk stratification, and a clear understanding of diagnostic and prognostic value of any further testing 1. Targeted blood tests are reasonable in the evaluation of selected patients with syncope identified on the basis of clinical assessment from history, physical examination, and ECG 1. Routine and comprehensive laboratory testing is not useful in the evaluation of patients with syncope 1. In patients without structural heart disease and a normal ECG, evaluation for neurally mediated syncope is recommended for those with recurrent or severe syncope 1. The tests for neurally mediated syncope consist of tilt testing and carotid massage. Loop monitoring is needed in patients with recurrent unexplained syncope whose symptoms are suggestive of arrhythmic syncope 1. Psychiatric assessment is recommended in patients with frequent recurrent syncope who have multiple other somatic complaints and whose initial evaluation raises concern in terms of stress, anxiety and other possible psychiatric disorders 1. The most important issue in these patients is the presence of structural heart disease or an abnormal ECG, which are associated with a higher risk of arrhythmias and a higher mortality at 1 year 1. In these patients, cardiac evaluation consisting of echocardiography, stress testing and tests for arrhythmia detection such as prolonged electrocardiographic and loop monitoring or electrophysiological study are recommended 1. Evaluation for neurally mediated syndromes is recommended in those with recurrent or severe syncope 1. The majority of patients with single or rare episodes in this category probably have neurally mediated syncope, and since treatment is generally not recommended in this group of patients, close follow-up without evaluation is recommended 1. Additional consideration in patients without structural heart disease and a normal ECG is bradyarrhythmia or psychiatric illness 1. ATP testing may be indicated at the end of the diagnostic work-up 1. In patients with suspected heart disease, echocardiography, prolonged electrocardiographic monitoring and, if non-diagnostic, electrophysiological studies are recommended as first evaluation steps 1. In patients with palpitations associated with syncope, electrocardiographic monitoring and echocardiography are recommended as first evaluation steps 1. In patients with chest pain suggestive of ischaemia before or after loss of consciousness, stress testing, echocardiography, and electrocardiographic monitoring are recommended as first evaluation steps 1. In young patients without suspicion of heart or neurological disease and recurrent syncope, tilt testing and, in older patients, carotid sinus massage are recommended as first evaluation steps 1. In patients with syncope occurring during neck turning, carotid sinus massage is recommended at the outset 1. In patients with syncope during or after effort, evaluation for cardiac causes is recommended 1. Basic laboratory tests are only indicated if syncope may be due to loss of circulating volume, or if a syncope-like disorder with a metabolic cause is suspected 1. In patients with suspected heart disease, cardiac evaluation is recommended as the first evaluation step 1. The diagnostic yield of laboratory tests is low when used routinely, but when these blood tests are conducted in patients with a suspected related diagnosis, test results can be diagnostic and useful for guiding therapy 1. Results have not been linked to clinical decision making or outcomes 1. Data to support specific blood testing are largely descriptive data from case series and registries 1. Complete blood count and electrolyte panel are frequently obtained during syncope evaluation, but the diagnostic yield is low when these are used routinely 1. Thus, specific testing should stem from the assessment by history and physical examination when the nature of the syncope presentation or associated comorbidities suggests a diagnostic or more likely prognostic role for laboratory testing 1. Although broad-panel testing is common in clinical practice at the point of triage, there are no data on the utility of this approach 1. Although data to support biomarker testing are in general relatively weak, there are sufficient data to suggest that natriuretic peptide is elevated in patients whose subsequent cause for syncope is determined to be cardiac 1. A systematic review of biomarkers found little value in contemporary troponin measurement unless acute myocardial infarction is suspected, and there is modest predictive value for high-sensitivity troponin and natriuretic peptides for major adverse cardiovascular events 1. The ability of troponin and natriuretic peptide measurement to influence clinical decision making or patient outcome is unknown 1. The selection of a given diagnostic test, after the initial history, physical examination, and baseline ECG, is a clinical decision based on the patient’s clinical presentation, risk stratification, and a clear understanding of diagnostic and prognostic value of any further testing 1. A broad-based use of additional testing is costly and often ineffective 1. This section provides recommendations for the most appropriate use of additional testing for syncope evaluation 1. See Figure 3 for the algorithm for additional evaluation and diagnosis for syncope 1. The diagnostic yield of laboratory tests is low when used routinely, but when these blood tests are conducted in patients with a suspected related diagnosis, test results can be diagnostic and useful for guiding therapy 1. Results have not been linked to clinical decision making or outcomes 1. Data to support specific blood testing are largely descriptive data from case series and registries 1. Complete blood count and electrolyte panel are frequently obtained during syncope evaluation, but the diagnostic yield is low when these are used routinely 1. Thus, specific testing should stem from the assessment by history and physical examination when the nature of the syncope presentation or associated comorbidities suggests a diagnostic or more likely prognostic role for laboratory testing 1. Although broad-panel testing is common in clinical practice at the point of triage, there are no data on the utility of this approach 1. Although data to support biomarker testing are in general relatively weak, there are sufficient data to suggest that natriuretic peptide is elevated in patients whose subsequent cause for syncope is determined to be cardiac 1. A systematic review of biomarkers found little value in contemporary troponin measurement unless acute myocardial infarction is suspected, and there is modest predictive value for high-sensitivity troponin and natriuretic peptides for major adverse cardiovascular events 1. The ability of troponin and natriuretic peptide measurement to influence clinical decision making or patient outcome is unknown 1. The selection of a given diagnostic test, after the initial history, physical examination, and baseline ECG, is a clinical decision based on the patient’s clinical presentation, risk stratification, and a clear understanding of diagnostic and prognostic value of any further testing 1. A broad-based use of additional testing is costly and often ineffective 1. This section provides recommendations for the most appropriate use of additional testing for syncope evaluation 1. See Figure 3 for the algorithm for additional evaluation and diagnosis for syncope 1. Some key points to consider when evaluating an adolescent female with fatigue and syncope include:

• The importance of a thorough history and physical examination in guiding the selection of diagnostic tests 1
• The need to rule out cardiac causes of syncope with an ECG and other cardiac evaluations as necessary 1
• The potential for orthostatic hypotension to cause syncope, and the importance of measuring orthostatic vital signs 1
• The possibility of anemia or other hematologic disorders contributing to fatigue and syncope, and the need for iron studies and other laboratory tests as indicated 1
• The potential for thyroid dysfunction or other endocrine disorders to cause fatigue, and the need for thyroid function tests and other endocrine evaluations as necessary 1
• The importance of considering referral to specialists such as cardiology, neurology, or endocrinology if initial testing is unrevealing and symptoms persist 1. Some potential laboratory tests to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Complete blood count (CBC) 1
• Comprehensive metabolic panel (CMP) 1
• Thyroid function tests (TSH, free T4) 1
• Iron studies (ferritin, iron, TIBC) 1
• Vitamin B12 and folate levels 1
• Electrocardiogram (ECG) 1
• Orthostatic vital signs 1
• Hemoglobin A1c 1
• Pregnancy test 1
• Urinalysis 1
• Electroencephalogram (EEG) if seizures are suspected 1. Some potential cardiac evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Echocardiography 1
• Prolonged electrocardiographic monitoring 1
• Electrophysiological studies 1
• Stress testing 1
• Loop monitoring 1
• Carotid sinus massage 1
• Tilt testing 1. Some potential endocrine evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Thyroid function tests (TSH, free T4) 1
• Adrenal function tests (e.g. cortisol, aldosterone) if indicated 1
• Other endocrine evaluations as necessary (e.g. growth hormone, insulin-like growth factor-1) 1. Some potential neurological evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Electroencephalogram (EEG) if seizures are suspected 1
• Imaging studies (e.g. MRI, CT) if indicated 1
• Other neurological evaluations as necessary (e.g. electromyography, nerve conduction studies) 1. Some potential hematologic evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Complete blood count (CBC) 1
• Iron studies (ferritin, iron, TIBC) 1
• Vitamin B12 and folate levels 1
• Other hematologic evaluations as necessary (e.g. coagulation studies, blood smear) 1. Some potential other evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Psychiatric assessment if indicated 1
• Sleep study if indicated 1
• Other evaluations as necessary (e.g. gastrointestinal, rheumatologic) 1. In summary, the evaluation of an adolescent female with fatigue and syncope should include a thorough history and physical examination, laboratory tests and cardiac evaluations as necessary, and consideration of referral to specialists if initial testing is unrevealing and symptoms persist. The selection of diagnostic tests should be based on the patient’s clinical presentation, risk stratification, and a clear understanding of diagnostic and prognostic value of any further testing 1. A broad-based use of additional testing is costly and often ineffective 1. This section provides recommendations for the most appropriate use of additional testing for syncope evaluation 1. See Figure 3 for the algorithm for additional evaluation and diagnosis for syncope 1. The diagnostic yield of laboratory tests is low when used routinely, but when these blood tests are conducted in patients with a suspected related diagnosis, test results can be diagnostic and useful for guiding therapy 1. Results have not been linked to clinical decision making or outcomes 1. Data to support specific blood testing are largely descriptive data from case series and registries 1. Complete blood count and electrolyte panel are frequently obtained during syncope evaluation, but the diagnostic yield is low when these are used routinely 1. Thus, specific testing should stem from the assessment by history and physical examination when the nature of the syncope presentation or associated comorbidities suggests a diagnostic or more likely prognostic role for laboratory testing 1. Although broad-panel testing is common in clinical practice at the point of triage, there are no data on the utility of this approach 1. Although data to support biomarker testing are in general relatively weak, there are sufficient data to suggest that natriuretic peptide is elevated in patients whose subsequent cause for syncope is determined to be cardiac 1. A systematic review of biomarkers found little value in contemporary troponin measurement unless acute myocardial infarction is suspected, and there is modest predictive value for high-sensitivity troponin and natriuretic peptides for major adverse cardiovascular events 1. The ability of troponin and natriuretic peptide measurement to influence clinical decision making or patient outcome is unknown 1. The selection of a given diagnostic test, after the initial history, physical examination, and baseline ECG, is a clinical decision based on the patient’s clinical presentation, risk stratification, and a clear understanding of diagnostic and prognostic value of any further testing 1. A broad-based use of additional testing is costly and often ineffective 1. This section provides recommendations for the most appropriate use of additional testing for syncope evaluation 1. See Figure 3 for the algorithm for additional evaluation and diagnosis for syncope 1. The diagnostic yield of laboratory tests is low when used routinely, but when these blood tests are conducted in patients with a suspected related diagnosis, test results can be diagnostic and useful for guiding therapy 1. Results have not been linked to clinical decision making or outcomes 1. Data to support specific blood testing are largely descriptive data from case series and registries 1. Complete blood count and electrolyte panel are frequently obtained during syncope evaluation, but the diagnostic yield is low when these are used routinely 1. Thus, specific testing should stem from the assessment by history and physical examination when the nature of the syncope presentation or associated comorbidities suggests a diagnostic or more likely prognostic role for laboratory testing 1. Although broad-panel testing is common in clinical practice at the point of triage, there are no data on the utility of this approach 1. Although data to support biomarker testing are in general relatively weak, there are sufficient data to suggest that natriuretic peptide is elevated in patients whose subsequent cause for syncope is determined to be cardiac 1. A systematic review of biomarkers found little value in contemporary troponin measurement unless acute myocardial infarction is suspected, and there is modest predictive value for high-sensitivity troponin and natriuretic peptides for major adverse cardiovascular events 1. The ability of troponin and natriuretic peptide measurement to influence clinical decision making or patient outcome is unknown 1. The selection of a given diagnostic test, after the initial history, physical examination, and baseline ECG, is a clinical decision based on the patient’s clinical presentation, risk stratification, and a clear understanding of diagnostic and prognostic value of any further testing 1. A broad-based use of additional testing is costly and often ineffective 1. This section provides recommendations for the most appropriate use of additional testing for syncope evaluation 1. See Figure 3 for the algorithm for additional evaluation and diagnosis for syncope 1. Some key points to consider when evaluating an adolescent female with fatigue and syncope include:
• The importance of a thorough history and physical examination in guiding the selection of diagnostic tests 1
• The need to rule out cardiac causes of syncope with an ECG and other cardiac evaluations as necessary 1
• The potential for orthostatic hypotension to cause syncope, and the importance of measuring orthostatic vital signs 1
• The possibility of anemia or other hematologic disorders contributing to fatigue and syncope, and the need for iron studies and other laboratory tests as indicated 1
• The potential for thyroid dysfunction or other endocrine disorders to cause fatigue, and the need for thyroid function tests and other endocrine evaluations as necessary 1
• The importance of considering referral to specialists such as cardiology, neurology, or endocrinology if initial testing is unrevealing and symptoms persist 1. Some potential laboratory tests to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Complete blood count (CBC) 1
• Comprehensive metabolic panel (CMP) 1
• Thyroid function tests (TSH, free T4) 1
• Iron studies (ferritin, iron, TIBC) 1
• Vitamin B12 and folate levels 1
• Electrocardiogram (ECG) 1
• Orthostatic vital signs 1
• Hemoglobin A1c 1
• Pregnancy test 1
• Urinalysis 1
• Electroencephalogram (EEG) if seizures are suspected 1. Some potential cardiac evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Echocardiography 1
• Prolonged electrocardiographic monitoring 1
• Electrophysiological studies 1
• Stress testing 1
• Loop monitoring 1
• Carotid sinus massage 1
• Tilt testing 1. Some potential endocrine evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Thyroid function tests (TSH, free T4) 1
• Adrenal function tests (e.g. cortisol, aldosterone) if indicated 1
• Other endocrine evaluations as necessary (e.g. growth hormone, insulin-like growth factor-1) 1. Some potential neurological evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Electroencephalogram (EEG) if seizures are suspected 1
• Imaging studies (e.g. MRI, CT) if indicated 1
• Other neurological evaluations as necessary (e.g. electromyography, nerve conduction studies) 1. Some potential hematologic evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Complete blood count (CBC) 1
• Iron studies (ferritin, iron, TIBC) 1
• Vitamin B12 and folate levels 1
• Other hematologic evaluations as necessary (e.g. coagulation studies, blood smear) 1. Some potential other evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Psychiatric assessment if indicated 1
• Sleep study if indicated 1
• Other evaluations as necessary (e.g. gastrointestinal, rheumatologic) 1. In summary, the evaluation of an adolescent female with fatigue and syncope should include a thorough history and physical examination, laboratory tests and cardiac evaluations as necessary, and consideration of referral to specialists if initial testing is unrevealing and symptoms persist. The selection of diagnostic tests should be based on the patient’s clinical presentation, risk stratification, and a clear understanding of diagnostic and prognostic value of any further testing 1. A broad-based use of additional testing is costly and often ineffective 1. This section provides recommendations for the most appropriate use of additional testing for syncope evaluation 1. See Figure 3 for the algorithm for additional evaluation and diagnosis for syncope 1. The diagnostic yield of laboratory tests is low when used routinely, but when these blood tests are conducted in patients with a suspected related diagnosis, test results can be diagnostic and useful for guiding therapy 1. Results have not been linked to clinical decision making or outcomes 1. Data to support specific blood testing are largely descriptive data from case series and registries 1. Complete blood count and electrolyte panel are frequently obtained during syncope evaluation, but the diagnostic yield is low when these are used routinely 1. Thus, specific testing should stem from the assessment by history and physical examination when the nature of the syncope presentation or associated comorbidities suggests a diagnostic or more likely prognostic role for laboratory testing 1. Although broad-panel testing is common in clinical practice at the point of triage, there are no data on the utility of this approach 1. Although data to support biomarker testing are in general relatively weak, there are sufficient data to suggest that natriuretic peptide is elevated in patients whose subsequent cause for syncope is determined to be cardiac 1. A systematic review of biomarkers found little value in contemporary troponin measurement unless acute myocardial infarction is suspected, and there is modest predictive value for high-sensitivity troponin and natriuretic peptides for major adverse cardiovascular events 1. The ability of troponin and natriuretic peptide measurement to influence clinical decision making or patient outcome is unknown 1. The selection of a given diagnostic test, after the initial history, physical examination, and baseline ECG, is a clinical decision based on the patient’s clinical presentation, risk stratification, and a clear understanding of diagnostic and prognostic value of any further testing 1. A broad-based use of additional testing is costly and often ineffective 1. This section provides recommendations for the most appropriate use of additional testing for syncope evaluation 1. See Figure 3 for the algorithm for additional evaluation and diagnosis for syncope 1. Some key points to consider when evaluating an adolescent female with fatigue and syncope include:
• The importance of a thorough history and physical examination in guiding the selection of diagnostic tests 1
• The need to rule out cardiac causes of syncope with an ECG and other cardiac evaluations as necessary 1
• The potential for orthostatic hypotension to cause syncope, and the importance of measuring orthostatic vital signs 1
• The possibility of anemia or other hematologic disorders contributing to fatigue and syncope, and the need for iron studies and other laboratory tests as indicated 1
• The potential for thyroid dysfunction or other endocrine disorders to cause fatigue, and the need for thyroid function tests and other endocrine evaluations as necessary 1
• The importance of considering referral to specialists such as cardiology, neurology, or endocrinology if initial testing is unrevealing and symptoms persist 1. Some potential laboratory tests to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Complete blood count (CBC) 1
• Comprehensive metabolic panel (CMP) 1
• Thyroid function tests (TSH, free T4) 1
• Iron studies (ferritin, iron, TIBC) 1
• Vitamin B12 and folate levels 1
• Electrocardiogram (ECG) 1
• Orthostatic vital signs 1
• Hemoglobin A1c 1
• Pregnancy test 1
• Urinalysis 1
• Electroencephalogram (EEG) if seizures are suspected 1. Some potential cardiac evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Echocardiography 1
• Prolonged electrocardiographic monitoring 1
• Electrophysiological studies 1
• Stress testing 1
• Loop monitoring 1
• Carotid sinus massage 1
• Tilt testing 1. Some potential endocrine evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Thyroid function tests (TSH, free T4) 1
• Adrenal function tests (e.g. cortisol, aldosterone) if indicated 1
• Other endocrine evaluations as necessary (e.g. growth hormone, insulin-like growth factor-1) 1. Some potential neurological evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Electroencephalogram (EEG) if seizures are suspected 1
• Imaging studies (e.g. MRI, CT) if indicated 1
• Other neurological evaluations as necessary (e.g. electromyography, nerve conduction studies) 1. Some potential hematologic evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Complete blood count (CBC) 1
• Iron studies (ferritin, iron, TIBC) 1
• Vitamin B12 and folate levels 1
• Other hematologic evaluations as necessary (e.g. coagulation studies, blood smear) 1. Some potential other evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Psychiatric assessment if indicated 1
• Sleep study if indicated 1
• Other evaluations as necessary (e.g. gastrointestinal, rheumatologic) 1. In summary, the evaluation of an adolescent female with fatigue and syncope should include a thorough history and physical examination, laboratory tests and cardiac evaluations as necessary, and consideration of referral to specialists if initial testing is unrevealing and symptoms persist. The selection of diagnostic tests should be based on the patient’s clinical presentation, risk stratification, and a clear understanding of diagnostic and prognostic value of any further testing 1. A broad-based use of additional testing is costly and often ineffective 1. This section provides recommendations for the most appropriate use of additional testing for syncope evaluation 1. See Figure 3 for the algorithm for additional evaluation and diagnosis for syncope 1. The diagnostic yield of laboratory tests is low when used routinely, but when these blood tests are conducted in patients with a suspected related diagnosis, test results can be diagnostic and useful for guiding therapy 1. Results have not been linked to clinical decision making or outcomes 1. Data to support specific blood testing are largely descriptive data from case series and registries 1. Complete blood count and electrolyte panel are frequently obtained during syncope evaluation, but the diagnostic yield is low when these are used routinely 1. Thus, specific testing should stem from the assessment by history and physical examination when the nature of the syncope presentation or associated comorbidities suggests a diagnostic or more likely prognostic role for laboratory testing 1. Although broad-panel testing is common in clinical practice at the point of triage, there are no data on the utility of this approach 1. Although data to support biomarker testing are in general relatively weak, there are sufficient data to suggest that natriuretic peptide is elevated in patients whose subsequent cause for syncope is determined to be cardiac 1. A systematic review of biomarkers found little value in contemporary troponin measurement unless acute myocardial infarction is suspected, and there is modest predictive value for high-sensitivity troponin and natriuretic peptides for major adverse cardiovascular events 1. The ability of troponin and natriuretic peptide measurement to influence clinical decision making or patient outcome is unknown 1. The selection of a given diagnostic test, after the initial history, physical examination, and baseline ECG, is a clinical decision based on the patient’s clinical presentation, risk stratification, and a clear understanding of diagnostic and prognostic value of any further testing 1. A broad-based use of additional testing is costly and often ineffective 1. This section provides recommendations for the most appropriate use of additional testing for syncope evaluation 1. See Figure 3 for the algorithm for additional evaluation and diagnosis for syncope 1. Some key points to consider when evaluating an adolescent female with fatigue and syncope include:
• The importance of a thorough history and physical examination in guiding the selection of diagnostic tests 1
• The need to rule out cardiac causes of syncope with an ECG and other cardiac evaluations as necessary 1
• The potential for orthostatic hypotension to cause syncope, and the importance of measuring orthostatic vital signs 1
• The possibility of anemia or other hematologic disorders contributing to fatigue and syncope, and the need for iron studies and other laboratory tests as indicated 1
• The potential for thyroid dysfunction or other endocrine disorders to cause fatigue, and the need for thyroid function tests and other endocrine evaluations as necessary 1
• The importance of considering referral to specialists such as cardiology, neurology, or endocrinology if initial testing is unrevealing and symptoms persist 1. Some potential laboratory tests to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Complete blood count (CBC) 1
• Comprehensive metabolic panel (CMP) 1
• Thyroid function tests (TSH, free T4) 1
• Iron studies (ferritin, iron, TIBC) 1
• Vitamin B12 and folate levels 1
• Electrocardiogram (ECG) 1
• Orthostatic vital signs 1
• Hemoglobin A1c 1
• Pregnancy test 1
• Urinalysis 1
• Electroencephalogram (EEG) if seizures are suspected 1. Some potential cardiac evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Echocardiography 1
• Prolonged electrocardiographic monitoring 1
• Electrophysiological studies 1
• Stress testing 1
• Loop monitoring 1
• Carotid sinus massage 1
• Tilt testing 1. Some potential endocrine evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Thyroid function tests (TSH, free T4) 1
• Adrenal function tests (e.g. cortisol, aldosterone) if indicated 1
• Other endocrine evaluations as necessary (e.g. growth hormone, insulin-like growth factor-1) 1. Some potential neurological evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Electroencephalogram (EEG) if seizures are suspected 1
• Imaging studies (e.g. MRI, CT) if indicated 1
• Other neurological evaluations as necessary (e.g. electromyography, nerve conduction studies) 1. Some potential hematologic evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Complete blood count (CBC) 1
• Iron studies (ferritin, iron, TIBC) 1
• Vitamin B12 and folate levels 1
• Other hematologic evaluations as necessary (e.g. coagulation studies, blood smear) 1. Some potential other evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Psychiatric assessment if indicated 1
• Sleep study if indicated 1
• Other evaluations as necessary (e.g. gastrointestinal, rheumatologic) 1. In summary, the evaluation of an adolescent female with fatigue and syncope should include a thorough history and physical examination, laboratory tests and cardiac evaluations as necessary, and consideration of referral to specialists if initial testing is unrevealing and symptoms persist. The selection of diagnostic tests should be based on the patient’s clinical presentation, risk stratification, and a clear understanding of diagnostic and prognostic value of any further testing 1. A broad-based use of additional testing is costly and often ineffective 1. This section provides recommendations for the most appropriate use of additional testing for syncope evaluation 1. See Figure 3 for the algorithm for additional evaluation and diagnosis for syncope 1. The diagnostic yield of laboratory tests is low when used routinely, but when these blood tests are conducted in patients with a suspected related diagnosis, test results can be diagnostic and useful for guiding therapy 1. Results have not been linked to clinical decision making or outcomes 1. Data to support specific blood testing are largely descriptive data from case series and registries 1. Complete blood count and electrolyte panel are frequently obtained during syncope evaluation, but the diagnostic yield is low when these are used routinely 1. Thus, specific testing should stem from the assessment by history and physical examination when the nature of the syncope presentation or associated comorbidities suggests a diagnostic or more likely prognostic role for laboratory testing 1. Although broad-panel testing is common in clinical practice at the point of triage, there are no data on the utility of this approach 1. Although data to support biomarker testing are in general relatively weak, there are sufficient data to suggest that natriuretic peptide is elevated in patients whose subsequent cause for syncope is determined to be cardiac 1. A systematic review of biomarkers found little value in contemporary troponin measurement unless acute myocardial infarction is suspected, and there is modest predictive value for high-sensitivity troponin and natriuretic peptides for major adverse cardiovascular events 1. The ability of troponin and natriuretic peptide measurement to influence clinical decision making or patient outcome is unknown 1. The selection of a given diagnostic test, after the initial history, physical examination, and baseline ECG, is a clinical decision based on the patient’s clinical presentation, risk stratification, and a clear understanding of diagnostic and prognostic value of any further testing 1. A broad-based use of additional testing is costly and often ineffective 1. This section provides recommendations for the most appropriate use of additional testing for syncope evaluation 1. See Figure 3 for the algorithm for additional evaluation and diagnosis for syncope 1. Some key points to consider when evaluating an adolescent female with fatigue and syncope include:
• The importance of a thorough history and physical examination in guiding the selection of diagnostic tests 1
• The need to rule out cardiac causes of syncope with an ECG and other cardiac evaluations as necessary 1
• The potential for orthostatic hypotension to cause syncope, and the importance of measuring orthostatic vital signs 1
• The possibility of anemia or other hematologic disorders contributing to fatigue and syncope, and the need for iron studies and other laboratory tests as indicated 1
• The potential for thyroid dysfunction or other endocrine disorders to cause fatigue, and the need for thyroid function tests and other endocrine evaluations as necessary 1
• The importance of considering referral to specialists such as cardiology, neurology, or endocrinology if initial testing is unrevealing and symptoms persist 1. Some potential laboratory tests to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Complete blood count (CBC) 1
• Comprehensive metabolic panel (CMP) 1
• Thyroid function tests (TSH, free T4) 1
• Iron studies (ferritin, iron, TIBC) 1
• Vitamin B12 and folate levels 1
• Electrocardiogram (ECG) 1
• Orthostatic vital signs 1
• Hemoglobin A1c 1
• Pregnancy test 1
• Urinalysis 1
• Electroencephalogram (EEG) if seizures are suspected 1. Some potential cardiac evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Echocardiography 1
• Prolonged electrocardiographic monitoring 1
• Electrophysiological studies 1
• Stress testing 1
• Loop monitoring 1
• Carotid sinus massage 1
• Tilt testing 1. Some potential endocrine evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Thyroid function tests (TSH, free T4) 1
• Adrenal function tests (e.g. cortisol, aldosterone) if indicated 1
• Other endocrine evaluations as necessary (e.g. growth hormone, insulin-like growth factor-1) 1. Some potential neurological evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Electroencephalogram (EEG) if seizures are suspected 1
• Imaging studies (e.g. MRI, CT) if indicated 1
• Other neurological evaluations as necessary (e.g. electromyography, nerve conduction studies) 1. Some potential hematologic evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Complete blood count (CBC) 1
• Iron studies (ferritin, iron, TIBC) 1
• Vitamin B12 and folate levels 1
• Other hematologic evaluations as necessary (e.g. coagulation studies, blood smear) 1. Some potential other evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Psychiatric assessment if indicated 1
• Sleep study if indicated 1
• Other evaluations as necessary (e.g. gastrointestinal, rheumatologic) 1. In summary, the evaluation of an adolescent female with fatigue and syncope should include a thorough history and physical examination, laboratory tests and cardiac evaluations as necessary, and consideration of referral to specialists if initial testing is unrevealing and symptoms persist. The selection of diagnostic tests should be based on the patient’s clinical presentation, risk stratification, and a clear understanding of diagnostic and prognostic value of any further testing 1. A broad-based use of additional testing is costly and often ineffective 1. This section provides recommendations for the most appropriate use of additional testing for syncope evaluation 1. See Figure 3 for the algorithm for additional evaluation and diagnosis for syncope 1. The diagnostic yield of laboratory tests is low when used routinely, but when these blood tests are conducted in patients with a suspected related diagnosis, test results can be diagnostic and useful for guiding therapy 1. Results have not been linked to clinical decision making or outcomes 1. Data to support specific blood testing are largely descriptive data from case series and registries 1. Complete blood count and electrolyte panel are frequently obtained during syncope evaluation, but the diagnostic yield is low when these are used routinely 1. Thus, specific testing should stem from the assessment by history and physical examination when the nature of the syncope presentation or associated comorbidities suggests a diagnostic or more likely prognostic role for laboratory testing 1. Although broad-panel testing is common in clinical practice at the point of triage, there are no data on the utility of this approach 1. Although data to support biomarker testing are in general relatively weak, there are sufficient data to suggest that natriuretic peptide is elevated in patients whose subsequent cause for syncope is determined to be cardiac 1. A systematic review of biomarkers found little value in contemporary troponin measurement unless acute myocardial infarction is suspected, and there is modest predictive value for high-sensitivity troponin and natriuretic peptides for major adverse cardiovascular events 1. The ability of troponin and natriuretic peptide measurement to influence clinical decision making or patient outcome is unknown 1. The selection of a given diagnostic test, after the initial history, physical examination, and baseline ECG, is a clinical decision based on the patient’s clinical presentation, risk stratification, and a clear understanding of diagnostic and prognostic value of any further testing 1. A broad-based use of additional testing is costly and often ineffective 1. This section provides recommendations for the most appropriate use of additional testing for syncope evaluation 1. See Figure 3 for the algorithm for additional evaluation and diagnosis for syncope 1. Some key points to consider when evaluating an adolescent female with fatigue and syncope include:
• The importance of a thorough history and physical examination in guiding the selection of diagnostic tests 1
• The need to rule out cardiac causes of syncope with an ECG and other cardiac evaluations as necessary 1
• The potential for orthostatic hypotension to cause syncope, and the importance of measuring orthostatic vital signs 1
• The possibility of anemia or other hematologic disorders contributing to fatigue and syncope, and the need for iron studies and other laboratory tests as indicated 1
• The potential for thyroid dysfunction or other endocrine disorders to cause fatigue, and the need for thyroid function tests and other endocrine evaluations as necessary 1
• The importance of considering referral to specialists such as cardiology, neurology, or endocrinology if initial testing is unrevealing and symptoms persist 1. Some potential laboratory tests to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Complete blood count (CBC) 1
• Comprehensive metabolic panel (CMP) 1
• Thyroid function tests (TSH, free T4) 1
• Iron studies (ferritin, iron, TIBC) 1
• Vitamin B12 and folate levels 1
• Electrocardiogram (ECG) 1
• Orthostatic vital signs 1
• Hemoglobin A1c 1
• Pregnancy test 1
• Urinalysis 1
• Electroencephalogram (EEG) if seizures are suspected 1. Some potential cardiac evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Echocardiography 1
• Prolonged electrocardiographic monitoring 1
• Electrophysiological studies 1
• Stress testing 1
• Loop monitoring 1
• Carotid sinus massage 1
• Tilt testing 1. Some potential endocrine evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Thyroid function tests (TSH, free T4) 1
• Adrenal function tests (e.g. cortisol, aldosterone) if indicated 1
• Other endocrine evaluations as necessary (e.g. growth hormone, insulin-like growth factor-1) 1. Some potential neurological evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Electroencephalogram (EEG) if seizures are suspected 1
• Imaging studies (e.g. MRI, CT) if indicated 1
• Other neurological evaluations as necessary (e.g. electromyography, nerve conduction studies) 1. Some potential hematologic evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Complete blood count (CBC) 1
• Iron studies (ferritin, iron, TIBC) 1
• Vitamin B12 and folate levels 1
• Other hematologic evaluations as necessary (e.g. coagulation studies, blood smear) 1. Some potential other evaluations to consider in the evaluation of an adolescent female with fatigue and syncope include:
• Psychiatric assessment if indicated 1
• Sleep study if indicated 1
• Other evaluations as necessary (e.g. gastrointestinal, rheumatologic) 1. In summary, the evaluation of an adolescent female with fatigue and syncope should include a thorough history and physical examination, laboratory tests and cardiac evaluations as necessary, and consideration of referral to specialists if initial testing is unrevealing and symptoms persist. The selection of diagnostic tests should be based on the patient’s clinical presentation, risk stratification, and a clear understanding of diagnostic and prognostic value of any further testing 1. A broad-based use of additional testing is costly and often ineffective 1. This section provides recommendations for the most appropriate use of additional testing for syncope evaluation 1. See Figure 3 for the algorithm for additional evaluation and diagnosis for syncope 1. The diagnostic yield of laboratory tests is low when used routinely, but when these blood tests are conducted in patients with a suspected related diagnosis, test results can be diagnostic and useful for guiding therapy 1. Results have not been linked to clinical decision making or outcomes 1. Data to support specific blood testing are largely descriptive data from case series and registries 1. Complete blood count and electrolyte panel are frequently obtained during syncope evaluation, but the diagnostic yield is low when these are used routinely 1. Thus, specific testing should stem from the assessment by history and physical examination when the nature of the syncope presentation or associated comorbidities suggests a diagnostic or more likely prognostic role for laboratory testing 1. Although broad-panel testing is common in clinical practice at the point of triage, there are no data on the utility of this approach 1. Although data to support biomarker testing are in general relatively weak, there are sufficient data to suggest that natriuretic peptide is elevated in patients whose subsequent cause for syncope is determined to be cardiac 1. A systematic review of biomarkers found little value in contemporary troponin measurement unless acute myocardial infarction is suspected, and there is modest predictive value for high-sensitivity troponin and natriuretic peptides for major adverse cardiovascular events 1. The ability of troponin and natriuretic peptide measurement to influence clinical decision making or patient outcome is unknown 1. The selection of a given diagnostic test, after the initial history, physical examination, and baseline ECG, is a clinical decision based on the patient’s clinical presentation, risk stratification, and a clear understanding of diagnostic and prognostic value of any further testing 1. A broad-based use of additional testing is costly and often ineffective 1. This section provides recommendations for the most appropriate use of additional testing for syncope evaluation 1. See Figure 3 for the algorithm for additional evaluation and diagnosis for syncope 1. Some key points to consider when evaluating an adolescent female with fatigue and syncope include:
• The importance of a thorough history and physical examination in guiding the selection of diagnostic tests 1
• The need to rule out cardiac causes of syncope with an ECG and other cardiac evaluations as necessary 1
• The potential for orthostatic hypotension to cause syncope, and the importance of measuring orthostatic vital signs 1
• The possibility of anemia or other hematologic disorders contributing to

From the Research

Diagnostic Approach for Female Adolescent Fatigue and Syncope

To approach the diagnosis of fatigue and syncope in female adolescents, it's crucial to consider a broad range of potential causes. The following steps and considerations can guide the diagnostic process:

• Initial Evaluation:
  • A thorough patient history to identify any preceding prodrome of dizziness, nausea, diaphoresis, and pallor 2, 3.
  • Comprehensive physical examination to assess for signs of cardiac or other systemic diseases.
• Laboratory Tests and Examinations:
  • Electrocardiogram (ECG) as a first-line diagnostic tool to identify potential cardiac causes of syncope 2, 4.
  • Consideration of further diagnostic tests such as echocardiography, ambulatory ECG, tilt-table tests, and exercise stress tests, but these should be used judiciously due to their expense and often low diagnostic yield 2.
• Differential Diagnosis:
  • Neurally mediated syncope (NMS) as a common cause, especially in young, healthy women, but emphasizing the importance of considering NMS as a diagnosis of exclusion 5.
  • Postural orthostatic tachycardia syndrome (POTS) and orthostatic hypotension as part of the differential diagnosis for syncope in young women 5.
• Guideline Adherence:
  • Adhering to current guidelines for the diagnosis and management of syncope to avoid unnecessary diagnostic tests and ensure appropriate patient care 4.

Considerations for Female Adolescents

Given the specific context of female adolescents, it's essential to be aware of the potential for benign forms of syncope while also maintaining a broad differential diagnosis to avoid missing more serious conditions 3, 5. Patient reassurance and education are crucial components of management, particularly for those diagnosed with benign forms of syncope 2.