Pericarditis differential diagnosis

For a full discussion of the differential diagnosis of chest pain click here

For an expert algorithm that aids in the diagnosis of the cause of chest pain click here

Overview
Signs and symptoms of pericarditis may be similar to several other conditions including myocardial infarction, aortic dissection and pulmonary embolism which are life threatening and therefore it is important to differentiate them. Pain along the trapezius ridge, which is unresponsive to vasodilator therapy and varies with position are signs specific for pericarditis.

Differentiating Pericarditis from other Conditions
Several conditions, including life threatening conditions such as myocardial infarction, aortic dissection and pulmonary embolism produce signs and symptoms that are similar to those produced by pericarditis. Although the following features are not 100% sensitive and/or specific in distinguishing the different causes of chest pain, they are useful guides:
 * Pain along the trapezius ridge(s), is very characteristic of pericarditis. The pain of myocardial infarction tends to involve the anterior precordium with either no radiation or radiation to either the jaw or the left arm.
 * Unlike cardiac ischemia, the pain of pericarditis often lasts longer, and is unresponsive to vasodilator therapy.
 * Ischemic chest pain is often described as a sense of "heaviness", "vice like", "pressure like", or like "an elephant sitting on the chest". The pain of pericarditis is often sharp and pleuritic (exacerbated by breathing in).
 * Ischemic chest pain is generally not positional in nature whereas the pain of pericarditis is relieved by sitting up and bending forward and worsened by lying down (recumbent or supine position) or inspiration (taking a breath in)
 * The EKG of pericarditis shows PR segment depression while the EKG of myocardial infarction does not (unless there is atrial infarction).
 * The EKG of pericarditis shows ST elevation that does not necessarily follow the anatomic distribution of a single coronary artery.
 * Other symptoms of pericarditis may include a viral prodrome including dry cough, fever, and fatigue.

These differentiating features are summarized in the table below

Chest Pain Following Myocardial Infarction
It should be noted that ST elevation MI can also be associated with the subsequent development of pericarditis. In a patient with recurrent chest pain following acute MI, one is often left wondering whether the chest pain is due to reocclusion of the culprit artery, or if it is due to the early development of pericarditis, or if it occurs later, if it is due to Dressler's syndrome. Occlusion of the culprit artery or stent thrombosis should be associated with recurrent ST segment elevation in the appropriate anatomic ECG leads.

Diagnosing Tuberculous Pericarditis: The Tygerberg Scoring System
Pericarditis caused by tuberculosis is difficult to diagnose, because definitive diagnosis requires culturing Mycobacterium tuberculosis from aspirated pericardial fluid or pericardial biopsy, which requires high technical skill and is often not diagnostic (the yield from culture is low even with optimum specimens).

The Tygerberg scoring system is useful in ascertaining if pericarditis is due to tuberculosis. In order to calculate the score, the points are added together:


 * Night sweats (1 point),
 * Weight loss (1 point),
 * Fever (2 point),
 * Serum globulin &gt; 40g/l (3 points),
 * Blood total leukocyte count &lt;10 x 109/l (3 points);

A total score of 6 or more is highly suggestive of tuberculous pericarditis.

Pericardial fluid with an interferon-γ level greater than 50pg/ml is highly specific for tuberculous pericarditis.