Final answer:
Reported symptoms and specific diagnostic tests like auscultation and echocardiograms are most helpful in diagnosing pericarditis. Surgery, ultrasound of the liver, and CT of the brain are not directly relevant to pericarditis diagnosis.
Step-by-step explanation:
When attempting to diagnose a patient with pericarditis, the most helpful intervention among the options provided would be C. Reported symptoms. In clinical practice, a combination of reported symptoms, physical examination, and various diagnostic tests are used to diagnose pericarditis. Auscultation using a stethoscope is a valuable initial diagnostic technique, where abnormal heart sounds indicative of conditions like pericarditis can be detected. Additional, more specific tests such as an echocardiogram can then be employed to visualize the heart and assess for pericardial inflammation. Other important tests that can assist in the diagnosis of pericarditis include a chest radiograph, electrocardiogram, aspiration of pericardial fluid, or biopsy of the pericardium if needed. The other interventions listed, such as surgery, ultrasound of the liver, and CT of the brain, are not directly helpful for diagnosing pericarditis