Table 1.

Diagnostic pathway and sequence of performance in acute pericarditis.^2,3

Diagnostic measure	Characteristic findings
Obligatory
Auscultation	Pericardial rub (mono-, bi-, or triphasic)
ECG*	Stage I: anterior and inferior concave ST segment elevation. PR segment deviations opposite to P wave polarity
	Early stage II: all ST junctions return to the baseline. PR segments deviated
	Late stage II: T waves progressively flatten and invert
	Stage III: generalised T wave inversions in most or all leads
	Stage IV: ECG returns to prepericarditis state
Echocardiography	Effusion types B-D (Horowitz)
	Signs of tamponade
Blood analyses	ESR, CRP, LDH, leucocytes (inflammation markers)
	Troponin I, CK-MB (markers of myocardial involvement)
Chest x ray	Ranging from normal to “water bottle” shape
	Performed primarily to reveal pulmonary or mediastinal pathology
Mandatory in tamponade, optional in large/recurrent effusions or if previous tests inconclusive in small effusions
Pericardiocentesis/drainage	PCR and histochemistry for aetiopathogenetic classification of infection or neoplasia
Optional or if previous tests inconclusive
CT	Effusions, peri-, and epicardium
MRI	Effusions, peri-, and epicardium
Pericardioscopy with pericardial/epicardial biopsy	Establishing the specific aetiology

*Typical lead involvement: I, II, aVL, aVF, and V3–V6. The ST segment is always depressed in aVR, frequently in V1, and occasionally in V2. Occasionally, stage IV does not occur and there are permanent T wave inversions and flattenings. If ECG is first recorded in stage III, pericarditis cannot be differentiated by ECG from diffuse myocardial injury, “biventricular strain” or myocarditis. ECG in early repolarisation is very similar to stage I. Unlike stage I, this ECG does not acutely evolve and J point elevations are usually accompanied by a slur, oscillation, or notch at the end of the QRS just before and including the J point (best seen with tall R and T waves—large in early repolarisation pattern). Pericarditis is likely if in lead V6 the J point is > 25% of the height of the T wave apex (using the PR segment as a baseline).

CK-MB, creatine kinase MB; CRP, C reactive protein; CT, computed tomography; ESR, erythrocyte sedimentation rate; LDH, lactate dehydrogenase;

MRI, magnetic resonance imaging; PCR, polymerase chain reaction.