What are the laboratory and electrocardiogram (ECG) findings for pericarditis?

From the Guidelines

Pericarditis is characterized by specific lab findings and ECG changes that aid in diagnosis, including elevated inflammatory markers such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), and cardiac biomarkers like troponin may be mildly elevated due to epicardial inflammation. The diagnosis of pericarditis involves a combination of clinical evaluation, laboratory tests, and imaging studies. According to the 2015 ESC guidelines for the diagnosis and management of pericardial diseases 1, a first diagnostic evaluation is recommended with auscultation, ECG, transthoracic echocardiography, chest X-ray, and routine blood tests, including markers of inflammation (i.e., CRP and/or ESR), white blood cell count with differential count, renal function, liver tests, and myocardial lesion tests (CK, troponins).

Key Lab Findings

• Elevated inflammatory markers such as CRP and ESR
• Mildly elevated cardiac biomarkers like troponin
• Leukocytosis on complete blood count
• Elevated lactate dehydrogenase (LDH) and protein levels in pericardial fluid, although these have not been validated for pericardial fluid 1

ECG Changes

• The classic ECG findings follow a progression of four stages: Stage 1 shows widespread ST-segment elevation (concave upward or "saddle-shaped") in most leads except aVR and V1, with PR-segment depression; Stage 2 (after several days) demonstrates normalization of ST segments and T waves; Stage 3 shows T-wave inversions; and Stage 4 shows normalization of the ECG or persistence of T-wave inversions. These findings are essential for accurate diagnosis and appropriate management of pericarditis, as noted in the 2015 ESC guidelines 1.

Imaging Studies

• Transthoracic echocardiography is recommended in all patients with suspected acute pericarditis to assess for pericardial effusion and cardiac tamponade 1
• Chest X-ray is recommended in all patients with suspected pericarditis to assess for cardiomegaly and pulmonary congestion 1
• CT and/or CMR are recommended as second-level testing for diagnostic workup in pericarditis, particularly in high-risk patients or those with suspected bacterial or neoplastic pericarditis 1

From the Research

Lab Findings for Pericarditis

• The diagnosis of pericarditis is often supported by electrocardiogram (ECG) changes, which can include widespread ST-segment elevation or PR depression 2, 3, 4.
• ECG changes can be dynamic and may evolve rapidly during the course of the disease, influenced by factors such as disease severity and treatment initiated 2.
• Laboratory tests may also include troponin levels, which can be elevated in cases of myocardial involvement 3.
• Cardiac magnetic resonance can be used to diagnose concurrent myocarditis and to assess pericardial inflammation and myocardial involvement 2, 3.

ECG Findings for Pericarditis

• Classic ECG criteria for pericarditis include widespread concave upward ST-segment elevation without reciprocal T-wave inversions or Q waves 4.
• ECG changes can be seen in less than 60% of patients with pericarditis, and may not be associated with a worse prognosis 3.
• New ECG criteria, including QRS and QT duration, may help differentiate acute pericarditis from myocardial infarction 5.
• ECG leads with maximal ST-segment elevation may show longer QRS complex and shorter QT interval in patients with STEMI, but not in patients with pericarditis 5.
• QT interval dispersion among the 12-ECG leads may be greater in STEMI than in patients with pericarditis 5.