Should a patient experiencing persistent fatigue undergo a cardiac workup, and if so, which type?

From the Guidelines

For a patient feeling tired all the time, a cardiac workup should be considered if initial evaluations for common causes of fatigue are unrevealing, and an echocardiogram is the recommended initial diagnostic test. When evaluating a patient with persistent fatigue, it's crucial to start with a comprehensive history, physical examination, and basic laboratory tests to rule out common causes such as anemia, thyroid disorders, and nutritional deficiencies. If these initial assessments do not reveal an underlying cause or if there are specific cardiac symptoms (chest pain, shortness of breath, palpitations) or risk factors (hypertension, diabetes, family history), then proceeding with a cardiac evaluation is warranted 1.

Key Considerations for Cardiac Workup

• The choice of cardiac workup should be guided by the presence of clinical signs or symptoms concerning for cardiac dysfunction.
• An echocardiogram is recommended as the initial diagnostic test for patients with suspected cardiac dysfunction, as per the American Society of Clinical Oncology clinical practice guideline 1.
• If an echocardiogram is not available or technically feasible, cardiac magnetic resonance imaging (MRI) or multigated acquisition (MUGA) scan can be considered, with a preference for cardiac MRI.
• Serum cardiac biomarkers (troponins, natriuretic peptides) or echocardiography-derived strain imaging can also be used in conjunction with routine diagnostic imaging.

Approach to Fatigue

• Fatigue is a nonspecific symptom with numerous potential causes, and a systematic approach to its evaluation is essential.
• Initial steps should focus on identifying and treating common causes of fatigue, such as anemia, thyroid disorders, and nutritional deficiencies.
• Only after these common causes have been ruled out or if specific cardiac risk factors or symptoms are present should a cardiac workup be initiated, starting with an echocardiogram as recommended by recent guidelines 1.

From the Research

Cardiac Workup for Fatigue

• A cardiac workup may not be the first line of investigation for patients presenting with fatigue, as evidenced by the study 2, which found that the majority of young healthy patients complaining of fatigue are not diagnosed with an organic physiological disorder.
• The study 3 describes various types of stress tests, including myocardial perfusion imaging, radionuclide angiography, stress echocardiography, and cardiopulmonary exercise testing, and provides guidelines for selecting a specific test for an individual patient.
• However, the study 3 suggests that standard treadmill exercise testing is widely available and is less expensive than the imaging techniques, and is most accurate in patients with normal findings on a resting electrocardiogram who are not taking digoxin.

Investigation of Fatigue

• The study 4 found that first-line investigations for fatigue in primary care include full blood count (FBC), renal function (U&Es), liver function tests (LFTs), thyroid-stimulating hormone (TSH), and bone profile, among others.
• The study 4 also found that the likelihood of abnormal results was highest for plasma viscosity (PV) and ferritin, and lowest for IgA tissue transglutaminase (TTG) and creatine kinase (CK).
• The study 5 provides an overview of the complete blood count (CBC) and its components, highlighting the important pathophysiological evidence they provide, and may be useful in informing the investigation of fatigue.

Choosing a Cardiac Workup

• Based on the study 3, the choice of cardiac workup will depend on the individual patient's presentation and medical history, as well as local expertise and the strengths and limitations of the various techniques.
• For patients with normal findings on a resting electrocardiogram who are not taking digoxin, standard treadmill exercise testing may be the most appropriate initial test 3.
• For patients with abnormal findings on a resting electrocardiogram, one of the stress imaging techniques, such as myocardial perfusion imaging or stress echocardiography, may be more appropriate 3.