From the Guidelines
The most appropriate diagnostic study for this patient is radiography of the chest (option C). This 35-year-old woman presents with symptoms highly suggestive of pericarditis, including sharp sternal chest pain that radiates to the back and left shoulder, worsens when lying down, and improves when upright. The physical examination finding of a faint intermittent rub at the left lower sternal border is particularly characteristic of pericarditis.
Key Points to Consider
- Chest radiography is the initial imaging study of choice for suspected pericarditis as it can help evaluate for cardiomegaly (which may indicate pericardial effusion), assess for pulmonary pathology that might cause similar symptoms, and rule out other thoracic conditions 1.
- According to the ACR Appropriateness Criteria, radiography of the chest is usually appropriate for the initial imaging of patients with nontraumatic chest wall pain with no history of malignancy 1.
- While an ECG would also be valuable in this case to look for diffuse ST-segment elevation typical of pericarditis, among the options provided, chest radiography is most appropriate as the first-line imaging study.
- The patient's recent exposure to students with respiratory illnesses suggests a possible viral etiology, which is the most common cause of pericarditis.
Rationale for Choosing Chest Radiography
- Other options like CT scan, pulmonary function testing, ultrasonography, or ventilation-perfusion scan would be excessive or less targeted for the initial evaluation of suspected pericarditis.
- The use of chest radiography as the initial imaging study aligns with the principle of minimizing radiation exposure while still providing valuable diagnostic information, especially considering the patient's age and the potential for radiation risk 1.
From the Research
Diagnostic Approach
The patient presents with sharp sternal chest pain that radiates to the back and left shoulder, worsens when lying down, and improves when upright. The physical examination reveals a faint intermittent rub at the left lower sternal border and an anterior tender point at rib 6 on the left. These findings suggest pericarditis, which is characterized by pleuritic chest pain and a pericardial friction rub on auscultation of the left lower sternal border 2.
Diagnostic Studies
The most appropriate diagnostic study for this patient would be:
- Radiography of the chest: This can help detect pericardial effusion, which may present as a globular heart shadow on chest X-ray 2.
- Ultrasonography of the chest (echocardiography): This can confirm the presence of effusion, constriction, or tamponade 2, 3.
Rationale
While other diagnostic studies such as CT scan of the chest, pulmonary function testing, and ventilation-perfusion scan may be useful in certain situations, they are not the most appropriate initial diagnostic studies for this patient.
- CT scan of the chest may be useful in detecting pericardial calcifications or thickening, but it is not the first-line diagnostic tool for pericarditis 4.
- Pulmonary function testing and ventilation-perfusion scan are more relevant for diagnosing respiratory diseases, which are not the primary concern in this patient's presentation.
- Ultrasonography of the chest (echocardiography) is a key diagnostic tool for pericarditis, as it can detect pericardial effusion and other complications such as tamponade 2, 3.
Key Findings
The patient's symptoms and physical examination findings are consistent with pericarditis, and the diagnostic studies should focus on confirming this diagnosis and detecting any potential complications. The use of radiography and ultrasonography of the chest can provide valuable information for diagnosing and managing pericarditis 2, 3, 5.