Pericarditis (Acute)
RCEM Learning: Acute Pericarditis
ACC Guidelines 2025 Concise Clinical Guidance: An ACC Expert Consensus Statement on the Diagnosis and Management of Pericarditis: A Report of the American College of Cardiology Solution Set Oversight Committee
Background Information
Definition
Acute pericarditis:
- Inflammation of the pericardium
- Pericarditis can co-exist with myocarditis (inflammation of the myocardium), termed myopericarditis
Aetiology
Causes include: [ref]
- Idiopathic
- Viral infection (e.g. Coxsackievirus)
- Bacterial, fungal and parasitic infection
- TB pericarditis is common in endemic areas
- Autoimmune disorders (e.g. SLE, RA, sarcoidosis)
- Metabolic causes (e.g. uraemia, myxoedema)
- Radiotherapy
- Malignancy
- Post-cardiac injury syndrome
- Post-myocardial infarction (Dressler syndrome)
- Post-cardiac procedures (~10% post AF ablation)
Complications
Acute complications: [ref]
- Pericardial effusion
- Cardiac tamponade
- Myopericarditis (poor prognosis – higher risk of heart failure)
- Atrial arrhythmia (e.g. AF or atrial flutter)
Chronic complications: [ref]
- Recurrence
- Constrictive pericarditis
Diagnosis
Diagnostic criteria: at least 2 out of 4 of the following are present:
- Characteristic chest pain
- Pericardial friction rub
- Suggestive ECG changes
- New or worsening pericardial effusion (on echocardiogram)
Clinical Features
Symptoms
Typical symptoms: [ref]
- Sudden onset of chest pain
- Pleuritic pain in nature
- Relieved by sitting up and learning forward, but worse lying flat (supine)
- Retrosternal (but can be anywhere else)
- Radiation to the trapezius ridge is highly specific for pericarditis
- Non-productive cough
It is important and common for exam questions to test one’s ability to differentiate between acute pericarditis and ACS. The following favours a diagnosis of acute pericarditis:
- Young age
- Absence of risk factors for coronary artery disease
- Preceding viral infection
- Chest pain nature (i.e. pleuritic, relieved by sitting up and learning forward, worse lying flat)
Signs
Possible examination findings include: [ref]
- Low-grade fever
- Pericardial friction rub on auscultation (<30% patients, but highly specific)
- Best heard on expiration at the lower left sternal edge while learning forward
- Audible when patient holds their breath (distinguishes from pleural rub)
- Muffled heart-sounds (esp. if associated with moderate-large pericardial effusions and/or tamponade)
- Features of the underlying cause
Investigations and Diagnosis
Initial Work Up
- Bloods
- ↑ WCC
- ↑ CRP
- Troponin
- normal or mildly elevated in isolated pericarditis
- ECG
- Imaging
- Echocardiography – pericardial effusion or even tamponade
- Chest X-ray – to exclude alternative causes of chest pain
ECG Findings
Characteristic ECG findings:
- Diffuse concave ST elevation
- Global PR depression
- Reciprocal changes in aVR and V1 (ST depression and PR elevation)
- Spodick’s sign (downsloping TP segment)
An important real-life and exam mimic of acute pericarditis is STEMI, as they both cause ST elevation on ECG.
Main distinguishing features are based on clinical presentation (see above) and ECG changes:
| ECG change | In STEMI | In acute pericarditis |
|---|---|---|
| ST elevation distribution | Localised to coronary artery territory (e.g. inferior leads, anterior leads) | Diffuse ‘global’ ST elevation across most leads, that does not follow the coronary artery territory |
| ST elevation morphology | Convex | Concave |
| Reciprocal ST depression | Seen in opposite coronary artery territory | Only seen in lead aVR |
| PR segment changes | No changes (unless there is concurrent heart block) | Diffuse PR depression (with reciprocal PR elevation in aVR) |
Management
Risk Stratification
If ANY of the following high-risk features are present → admit for inpatient management
- Fever (>38°C)
- Subacute course
- Large pericardial effusion (>20mm)
- Cardiac tamponade
- Failure to respond to aspirin / NSAIDs
- ↑ Troponin
- Immunosuppression
- Oral anticoagulant therapy
- Trauma
Management
Management depends on the cause of acute pericarditis.
Idiopathic / Viral Pericarditis
1st line: offer both of the following:
- Activity restriction
- Avoid strenuous physical activity until asymptomatic and biomarkers have normalised
- Advise athletes not to compete in competitive sports for at least 3 months post-resolution
- High-dose NSAIDs (usually ibuprofen or indomethacin) + colchicine
- Stop NSAIDs after symptom resolution
- Continue colchicine for another 3 months after symptom resolution
Consider low-dose steroids in those who did not respond to NSAIDs + colchicine
- For those with steroid dependence or multiple recurrences: IL-1 inhibitor (e.g. anakinra) is the steroid-sparing agent of choice
Dressler Syndrome
1st line: high-dose aspirin (until symptom resolves) + colchicine (until 3 months after symptom resolution)
Non-aspirin NSAIDs and steroids should be avoided due to increased risk of myocardial rupture and impaired healing after infarction.
TB Pericarditis
Treat with anti-tubercular therapy (usually rifampicin + isoniazid + vitamin B6 + pyrazinamide + ethambutol) +/- coritcosteroids
Any Other Causes
Treat underlying cause + supporitve care.
References