Diagnosis of Pericarditis
The diagnosis of pericarditis is usually first suggested by development of chest pain that worsens with taking a deep breath or lying down and that improves with sitting up and leaning forward.
The initial evaluation consists of a medical history, physical examination, and an electrocardiogram (ECG). The medical history focuses on chest pain:
- Does the pain get worse when you take a deep breath?
- Is it worse when you lie down?
- Does it get better after you sit up and lean forward?
The doctor or nurse usually inquires about recent infections (especially flu-like infections), a history of coronary artery disease or myocardial infarction (heart attack), symptoms that might suggest the presence of cancer, and medications that are being taken (some medications can cause pericarditis).
The physical examination focuses on careful listening through a stethoscope for the scratchy sounds called a pericardial rub, which are produced by heart muscle rubbing against the inflamed pericardium. These sounds strongly suggest the diagnosis of pericarditis. Other findings, such as distended veins in the neck and swollen ankles and feet, can suggest pericardial effusion, which often accompanies pericarditis.
Pericarditis frequently produces characteristic findings on the electrocardiogram (ECG), usually elevated ST segments in most areas analyzed by the test. These findings in conjunction with the characteristic pain and/or pericardial rub are usually enough for a physician to make a presumptive diagnosis of pericarditis. The ECG can also suggest other causes of chest pain, such as a recent or past heart attack.
Many patients are referred for an echocardiogram (cardiac echo). During this test, a microphone-like device transmits special "sound waves" that travel through the chest wall to the heart and are then reflected back to the device. The reflected sound waves are then translated into images of the heart and surrounding tissues.
The echocardiogram is usually unable to visualize the thin pericardium well enough to see the presence of inflammation. It is, however, very good at determining if pericardial effusion (accumulation of fluid between the pericardium and the heart) is developing. Pericardial effusion often results from pericarditis and provides supportive evidence for the diagnosis. From the echocardiogram, the physician can estimate the amount of fluid that has accumulated and whether the fluid is compressing the chambers of the heart.
It is important to remember that an echocardiogram cannot make or rule out the diagnosis of pericarditis, but it can detect pericardial effusion and may be ordered if this is suspected.
Since most cases of pericarditis in young healthy persons are due to a recent viral or bacterial infection or are idiopathic (i.e., without clear cause), further testing often is unnecessary to determine the cause. Further testing is more commonly needed in older patients and is dictated primarily by what the doctor or nurse suspects to be the cause. This may involve blood tests to make sure the kidneys are working properly and to assess for conditions in which the immune system is pathologically overactive, special tests to detect certain infections, and a chest x-ray to detect fluid accumulation around the heart or, rarely, tuberculosis or tumor as the cause.