Diagnosing Pericarditis

What criteria are required in order to establish a diagnosis of pericarditis?

The diagnosis is made upon:

  • Either hearing a pericardial friction rub OR eliciting a history of typical chest pain
  • AND demonstrating typical ECG findings (i.e. widespread concave ST Segment elevation)

Additional factors to consider:

85% of patients have an audible friction rub during the course of their disease.

15% of patients with idiopathic pericarditis and up to 60% of patients with neoplastic, TB or purulent pericarditis have clinical evidence of tamponade.

ECG findings include widespread concave ST elevation, reciprocal changes in lead AVR and widespread PR depression. The ST Segment to T wave height ratio in lead V6 is normally >0.25 [9].

Troponin levels are elevated in 35-50% of patients with pericarditis. Other blood tests (e.g. full blood count, viral serology) are of little help in finding a cause.

Echocardiography should be performed to aid diagnosis, to evaluate the size of any associated effusion and to look for other poor prognostic indicators.

Table 1: Prognostic indicators of Pericarditis

Poor prognostic indicators associated with pericarditis

Temp >38

Subacute onset (several weeks)

Immunosuppressed

Associated with trauma

Oral anticoagulant therapy

Myopericarditis

Large pericardial effusion (20mm width on echo)

Cardiac tamponade

Learning bite

Eighty-five percent of patients with pericarditis have a pericardial friction rub at some point during their illness.