After taking a medical history, a physical examination is performed. Auscultation, in which the physician listens to the patient’s heart sounds through a stethoscope, reveals a characteristic pattern, called a pericardial friction rub, in about one-half to two-thirds of patients who are diagnosed with this condition. This is a high-pitched, grating noise thought to be caused by tissue membranes rubbing against each other. There may also be crackles in the lungs, decreased breath sounds or other signs of fluid in the space around the lungs.

A series of diagnostic tests may confirm the presence of pericarditis. In the vast majority of patients in whom pericarditis is suspected, an echocardiogram will be taken. This test involves the use of ultrasound technology to produce three-dimensional images of the heart’s structures and functions.

The echocardiogram will provide information about the presence and extent of any fluid buildup in the pericardium. This test is used mainly to detect pericardial effusion and possibly dangerous cardiac tamponade. However, the absence of pericardial fluid does not rule out the presence of pericarditis. Other tests that may be run include:

• Electrocardiogram (EKG). Measures electrical activity in the heart and will reveal characteristic changes in the wave shape produced as a result of pericarditis. About 90 percent of patients with pericarditis have abnormal EKGs. Changes may occasionally mimic those occurring during a heart attack, but they tend to be more diffuse with pericarditis. In the case of constrictive pericarditis, atrial fibrillation, or abnormally fast rhythms that originate in the upper chambers of the heart, is detected in approximately one-third of patients examined.
  
  
• Blood tests. These tests may be used to determine underlying causes. For example, an elevated sedimentation rate may point to a collagen vascular disorder such as lupus, among others. Blood tests are also used to determine whether the patient is suffering from pericarditis or heart attack, the two may look similar on an EKG test. During a blood test, serum levels of cardiac biomarkers creatine kinase (CK-MB) and cardiac troponin may be measured. Other blood measures that may prove useful include an increased white blood cell count (measured as part of a complete blood count) and C-reactive protein, which shows inflammation in the body.
  
  
• Chest x-ray. May help to identify fluid buildup. The film will show a distinctive rounded shape in the chest area.
  
  
• CAT scan of chest. A noninvasive imaging technique that uses x-ray technology and can identify a thickened pericardium and pericardial fluid.
  
  
• Magnetic imaging resonance. MRI, also a noninvasive or minimaly invasive imaging technique, identifies thickening of the pericardium, abnormalities of the ventricles and calcification (hardening) of the pericardium with a greater resolution than other imaging options.

In general, any patient who exhibits chest pain, has an abnormal EKG and presents with a pericardial friction rub will likely be diagnosed with pericarditis.