Acute Pericarditis — Diagnosis and Treatment

Key Points

• Typical pericarditis pain is pleuritic, positional, and often relieved by sitting forward.
• Diffuse ST elevation and PR depression support the diagnosis but are not present in every case.
• Echocardiography evaluates effusion and tamponade but a normal study does not exclude pericarditis.
• Aspirin or an NSAID plus colchicine is standard first-line treatment for uncomplicated inflammatory pericarditis.
• Corticosteroids are not first-line therapy for routine idiopathic pericarditis.
• Troponin elevation suggests myocardial involvement and may change risk and exercise recommendations.
• Large effusion, tamponade, fever, immunosuppression, anticoagulation, subacute course, or treatment failure are high-risk features.
• Tamponade requires urgent drainage and should not be treated as simple pericarditis.

Algorithm

1. Assess chest pain, hemodynamics, ECG, and immediate life threats including ACS, PE, aortic syndrome, and tamponade.
2. Obtain ECG, troponin, CBC, metabolic panel, CRP or ESR, and chest imaging as clinically indicated.
3. Perform echocardiography to evaluate effusion and hemodynamic effect.
4. Confirm a compatible pericarditis syndrome and assess for myocardial involvement or a specific secondary cause.
5. Identify high-risk features that require admission or expanded etiologic evaluation.
6. For low-risk inflammatory pericarditis, start aspirin or an NSAID plus colchicine and gastroprotection when appropriate.
7. Avoid routine corticosteroids unless anti-inflammatory therapy is contraindicated or a specific indication exists after infection is considered.
8. Restrict exercise until symptoms and objective inflammation resolve.
9. Arrange follow-up for symptom response, CRP trend, medication tolerance, and recurrence.
10. Drain the pericardium urgently if tamponade develops.

Clinical Synopsis & Reasoning

Acute pericarditis is inflammation of the pericardial layers, most commonly idiopathic or presumed viral in higher-income settings but also associated with autoimmune disease, malignancy, uremia, tuberculosis, bacterial infection, post-cardiac injury, radiation, and medications. Typical pain is sharp and pleuritic, worse when supine or with deep inspiration, and improved by sitting forward. A pericardial friction rub is highly specific when present but can be transient. ECG classically shows diffuse concave ST-segment elevation with PR depression, although not every patient has the classic pattern.

Diagnosis is clinical and generally supported by at least two characteristic features such as typical chest pain, a pericardial rub, new widespread ST elevation or PR depression, and a new or worsening pericardial effusion. Inflammatory markers can support the diagnosis and help monitor response. Troponin elevation suggests myocardial involvement, changing the syndrome toward myopericarditis or perimyocarditis and potentially affecting exercise restriction and disposition.

The emergency task is to distinguish pericarditis from dangerous mimics. Acute coronary syndrome can produce regional ST elevation with reciprocal changes, pulmonary embolism can cause pleuritic pain and tachycardia, and aortic dissection can involve the pericardium and cause tamponade. Echocardiography evaluates effusion and hemodynamic effect but a normal echocardiogram does not exclude pericarditis. Tamponade is a separate emergency marked by impaired filling, hypotension, tachycardia, elevated venous pressure, pulsus paradoxus, and echocardiographic signs of chamber collapse.

High-risk features should prompt admission and evaluation for a specific cause. These include fever, subacute course, large effusion, tamponade, failure of anti-inflammatory therapy, immunosuppression, trauma, oral anticoagulant therapy, and evidence of myocardial involvement. Secondary causes such as bacterial infection, tuberculosis, malignancy, autoimmune disease, and uremia require cause-specific treatment rather than routine outpatient management alone.

Treatment Strategy & Disposition

For uncomplicated idiopathic or presumed viral acute pericarditis, aspirin or an NSAID is first-line anti-inflammatory treatment, generally with gastroprotection when appropriate. Colchicine is added because it improves symptom response and reduces recurrence. Dose selection depends on body weight, age, renal and hepatic function, interacting medications, and tolerability. Treatment duration for the anti-inflammatory drug is guided by symptoms and inflammatory-marker normalization rather than a fixed number of days, while colchicine is commonly continued for several months in a first episode.

Corticosteroids are not first-line therapy for uncomplicated idiopathic pericarditis because they increase recurrence risk and may worsen unrecognized infection. They have a role when aspirin and NSAIDs are contraindicated or ineffective and when there is a specific indication such as selected autoimmune disease, after infection has been appropriately excluded. Secondary pericarditis requires treatment of the cause, such as dialysis optimization for uremic disease or antimicrobial therapy for bacterial or tuberculous disease.

Restrict strenuous physical activity until symptoms resolve and inflammatory markers, ECG, and cardiac imaging normalize as appropriate. Athletes and patients with myocardial involvement require more conservative return-to-exercise planning. Patients with significant effusion require serial echocardiography. Hemodynamic tamponade requires urgent drainage rather than escalation of anti-inflammatory medication.

Low-risk patients with good follow-up can often be managed as outpatients. Admit patients with high-risk features, uncertain diagnosis, significant troponin elevation or myocardial dysfunction, large effusion, tamponade physiology, systemic illness, immunosuppression, anticoagulation-related concern, or failure of outpatient therapy.

Epidemiology / Risk Factors

• Idiopathic or presumed viral disease accounts for many acute pericarditis cases in settings with low tuberculosis prevalence.
• Recurrence is a major clinical burden and is reduced by colchicine.
• Secondary causes become more important in immunocompromised patients, patients with cancer, renal failure, systemic autoimmune disease, or epidemiologic risk for tuberculosis.
• Pericarditis can occur after myocardial infarction, cardiac surgery, ablation, or other cardiac injury.
• Myocardial involvement ranges from mild troponin elevation to clinically important myocarditis with ventricular dysfunction or arrhythmia.

Investigations

Therapeutic Snapshot

Pharmacology

Prognosis / Complications

• Most uncomplicated idiopathic or viral acute pericarditis resolves with anti-inflammatory treatment and has an excellent prognosis.
• Recurrence is common enough that colchicine and adequate initial treatment matter.
• Purulent, tuberculous, neoplastic, and uremic causes carry higher complication risk and require cause-specific therapy.
• Large effusion and tamponade increase acute risk.
• Myocardial dysfunction or significant ventricular arrhythmia suggests more extensive myocardial disease and warrants closer follow-up.

Patient Education / Counseling

• Take anti-inflammatory medication and colchicine exactly as prescribed and report GI intolerance or drug interactions.
• Avoid strenuous exercise until symptoms and objective inflammation have resolved and a clinician has cleared return to activity.
• Seek urgent care for fainting, worsening shortness of breath, persistent hypotension, rapidly increasing chest pressure, or new severe weakness because tamponade can develop.
• Explain that recurrence is possible even after the first episode resolves.
• Patients with kidney, GI, liver, or bleeding problems should review anti-inflammatory medication safety carefully.
• Follow-up should include reassessment of symptoms and inflammatory markers and echocardiography when effusion was present or symptoms change.

Notes

Acute pericarditis is usually benign, but the emergency clinician must first rule out the conditions that are not. A positional pleuritic pain story and diffuse ECG changes do not eliminate ACS, aortic disease, PE, or tamponade. Echocardiography and risk stratification determine whether outpatient anti-inflammatory treatment is appropriate.

ESC guidance continues to support aspirin or an NSAID plus colchicine as first-line therapy and recommends using inflammatory response, including CRP, to guide treatment. Corticosteroids remain a selective rather than routine first-line option because of recurrence risk.

References

1. European Society of Cardiology: Management of Acute Pericarditis — Link
2. European Society of Cardiology: Acute Pericarditis Practical Guidance — Link