Workup for Pericarditis
All patients with suspected pericarditis require a first-level diagnostic evaluation including auscultation, ECG, transthoracic echocardiography, chest X-ray, and routine blood tests (inflammatory markers, CBC with differential, renal/liver function, and cardiac biomarkers). 1
Diagnostic Criteria
The diagnosis of pericarditis requires at least 2 of the following 4 criteria: 2, 3
- Pericarditic chest pain: Sharp, retrosternal, pleuritic pain that worsens with inspiration and supine position, improves when sitting forward (present in ~90% of cases) 2, 3
- Pericardial friction rub: Auscultatory finding from friction between inflamed pericardial layers (present in <30% of cases) 2, 3
- ECG changes: New widespread ST-segment elevation or PR depression in multiple leads (present in 25-50% of cases) 2, 3
- Pericardial effusion: New or worsening effusion on imaging (present in ~60% of cases, most often small) 2, 3
First-Level Workup (Required for ALL Cases)
Physical Examination
- Cardiac auscultation for pericardial friction rub 1
Laboratory Tests
- Inflammatory markers: CRP and/or ESR 1
- Complete blood count with differential 1
- Cardiac biomarkers: Troponin and creatine kinase (CK) to assess for myocardial involvement 1, 2
- Renal function and liver tests 1
- Thyroid function 1
Imaging Studies
- 12-lead ECG 1
- Transthoracic echocardiography (mandatory in all cases) 1
- Chest X-ray (though often normal unless effusion exceeds 300 ml) 1, 2
Risk Stratification
Identify high-risk features that mandate hospital admission and extensive etiological workup: 1, 2
Major Risk Factors (validated by multivariate analysis):
- Fever >38°C (HR 3.56) 1, 2
- Subacute course (symptoms developing over days/weeks; HR 3.97) 1, 2
- Large pericardial effusion (diastolic echo-free space >20 mm; HR 2.15) 1, 2
- Cardiac tamponade (HR 2.51) 1, 2
- Failure to respond to aspirin/NSAIDs within 7 days (HR 2.50-5.50) 1, 2
Minor Risk Factors:
Second-Level Workup (For High-Risk Patients)
Advanced Imaging
- CT and/or cardiac MRI are indicated when first-level testing is insufficient for diagnosis 1
Invasive Procedures
Pericardiocentesis or surgical drainage is indicated for: 1
- Cardiac tamponade
- Suspected bacterial or neoplastic pericarditis
- Symptomatic moderate-to-large effusions not responding to medical therapy
Pericardial Fluid Analysis (when obtained):
- Cytology: Cell count, protein/LDH ratio >0.6 1
- Polymerase chain reaction (PCR): Especially for tuberculosis 1
- Microbiology: Mycobacterium cultures, aerobic and anaerobic cultures 1
Etiological Workup Based on Clinical Suspicion
For Suspected Autoimmune Disease:
- ANA, ENA, ANCA 1
- Ferritin (if Still disease suspected) 1
- ACE and 24-hour urinary calcium (if sarcoidosis suspected) 1
- Consider PET scan for large vessel arteritis or sarcoidosis 1
For Suspected Tuberculosis:
For Suspected Neoplasm:
For Suspected Viral Infection:
For Suspected Bacterial Infection:
- Blood cultures (before antibiotics) 1
- Serology for Coxiella burnetii (if Q-fever suspected) 1
- Serology for Borrelia species (if Lyme disease suspected) 1
Common Pitfalls and Caveats
- ECG changes may be absent in up to 40% of cases, so their absence does not exclude pericarditis 2
- Normal inflammatory markers do not exclude pericarditis, especially if the patient is already on anti-inflammatory treatment 2
- Cardiac biomarker elevation indicates concomitant myocarditis rather than primary pericardial disease 2
- The major specific causes to rule out are bacterial pericarditis (especially TB), neoplastic pericarditis, and autoimmune-associated pericarditis—each representing ~5% of cases in developed countries 1
- In endemic areas (e.g., sub-Saharan Africa), tuberculosis accounts for 70-80% of pericarditis cases, often associated with HIV infection 1
- CRP should be used to guide treatment duration and assess response to therapy 1