This diagnostic tool aims to evaluate the likelihood of acute pericarditis based on four key clinical criteria. Each criterion corresponds to common signs or findings associated with the condition:

- Characteristic symptoms of chest pain, described as sharp and pleuritic, which improve when the individual sits up and leans forward.
- Presence of a pericardial friction rub, identifiable as a scratchy or squeaking sound heard using a stethoscope over the left sternal border.
- Electrocardiogram (ECG) changes, specifically new diffuse ST segment elevation or PR depression during the acute phase.
- Detection of pericardial effusion via diagnostic imaging like an echocardiogram or computed tomography.

The tool operates on a simple logic: if any two or more of these criteria are met, acute pericarditis is considered likely. Specifically, the combinations it considers are:

- Characteristic chest pain and pericardial friction rub
- Characteristic chest pain and typical ECG changes
- Characteristic chest pain and pericardial effusion
- Pericardial friction rub and typical ECG changes
- Pericardial friction rub and pericardial effusion
- Typical ECG changes and pericardial effusion

The presence of two or more positive findings out of the four criteria signifies a high likelihood of acute pericarditis. Conversely, if fewer than two criteria are present, the condition is deemed unlikely. This decision-making process provides a structured approach to interpreting clinical evidence in diagnosing acute pericarditis, focusing on the correlation of symptoms, physical examination, and diagnostic findings.

The diagnostic criteria for acute pericarditis serve as a clinical tool for identifying patients with this condition. The primary purpose of these criteria is to facilitate accurate diagnosis and prompt treatment, thereby improving patient outcomes. The target patient population includes individuals presenting with symptoms suggestive of acute pericarditis.

The primary components of these diagnostic criteria include characteristic symptoms of chest pain, pericardial friction rub, typical electrocardiogram changes, and pericardial effusion identified on diagnostic imaging. The chest pain associated with acute pericarditis is typically sharp and pleuritic, and it improves when the patient sits up and leans forward. A pericardial friction rub is a superficial scratchy or squeaking sound best heard with the diaphragm of the stethoscope over the left sternal border. Typical electrocardiogram changes include new diffuse ST segment elevation or PR depression in the acute phase. Pericardial effusion can be identified through diagnostic imaging techniques such as echocardiogram or computed tomography.

The diagnosis of acute pericarditis is likely if any two of these criteria are met. Specifically, the combinations can be (A and B), (A and C), (A and D), (B and C), (B and D), or (C and D). If these combinations are not met, the diagnosis of acute pericarditis is considered unlikely. This approach allows for flexibility in diagnosis, accommodating the variability in clinical presentations of acute pericarditis.

Diagnostic criteria for acute pericarditis

2015 ESC Guidelines for the diagnosis and management of pericardial diseases: The Task Force for the Diagnosis and Management of Pericardial Diseases of the European Society of Cardiology (ESC) Endorsed by: The European Association for Cardio-Thoracic Surgery (EACTS).