Acute Pericarditis

Acute pericarditis is inflammation of the pericardium, accounting for approximately 4.4% of ED visits for nonischemic chest pain, with higher prevalence in men. Most cases in North America and Western Europe are idiopathic/viral (80–90%). With appropriate treatment, 70–85% of patients have a benign course. [1-2]

The following diagnostic and management algorithm from the AAFP provides a practical overview:

• Pain quality: Sharp, stabbing, pleuritic chest pain — worse when supine, improved by sitting up and leaning forward [1][3]
• Radiation to the trapezius ridge is virtually pathognomonic [3]
• Onset: Often abrupt; ask about preceding viral URI or gastroenteritis (1–3 weeks prior)
• Timing: Constant or intermittent; typically acute onset over hours
• Associated symptoms: Dyspnea, cough, fatigue, low-grade fever, malaise
• Important negatives: Exertional component (ACS), tearing quality (dissection), unilateral pleuritic pain with leg swelling (PE), dysphagia (esophageal), trauma history
• Ask about recent cardiac surgery or procedures (post-cardiac injury syndrome), prior pericarditis episodes, and autoimmune disease symptoms [1]

• Fever >38.5°C — suggests specific etiology (bacterial, TB, autoimmune) [3-4]
• Subacute onset (symptoms developing over days without clear onset) [1]
• Large pericardial effusion (>2.0 cm) or signs of cardiac tamponade (Beck's triad: hypotension, JVD, muffled heart sounds; pulsus paradoxus) [1][3]
• Failure to respond to NSAIDs within 1 week [1]
• Concomitant myocarditis (elevated troponin with LV dysfunction) [5]
• Suspected malignancy or immunocompromised state [1]
• Hemodynamic instability — tachycardia, hypotension

First-line (dual therapy)

• Ibuprofen 600–800 mg PO q8h (1600–2400 mg/day), taper by 200–400 mg every 2–4 weeks after symptom resolution and CRP normalization [1][6]
• OR Aspirin 650–1000 mg PO TID (preferred if concomitant CAD) [5][7]
• PLUS Colchicine 0.5 mg BID (>70 kg) or 0.5 mg daily (≤70 kg) for 3 months (first episode) or ≥6 months (recurrence) [1]
• Proton pump inhibitor for gastroprotection with NSAIDs [1][5]

Second-line

• Corticosteroids[5][7]

Third-line (recurrent/refractory)

• IL-1 blockers[8]

Contraindicated/Cautions

• Avoid anticoagulants if possible (risk of hemorrhagic pericardial effusion)
• NSAIDs: caution in CKD, HF, peptic ulcer disease, bleeding diathesis [5]
• Colchicine: dose-reduce with P-gp/CYP3A4 inhibitors; GI intolerance is common [5]

• No specific dietary triggers
• Adequate hydration, especially with NSAID use (renal protection)
• Avoid alcohol during acute illness (may exacerbate inflammation and interact with medications)

• Cardiovascular: Chest pain character, dyspnea, orthopnea, syncope/presyncope, palpitations
• Respiratory: Cough, pleuritic pain, dyspnea (pleural effusion common)
• Constitutional: Fever, night sweats, weight loss (TB, malignancy)
• MSK/Rheumatologic: Joint pain, rashes, oral ulcers (autoimmune)
• GI: Dysphagia, epigastric pain (alternative diagnoses)
• Infectious: Recent URI, GI illness, travel history, TB exposure

• Family history of pericarditis — may prompt genetic evaluation (familial Mediterranean fever), though yield is low [1]
• Family history of autoimmune disease (SLE, RA)
• Social context: Immigration from TB-endemic areas, incarceration, homelessness, HIV status [1]
• Recent cardiac surgery/catheterization (post-cardiac injury syndrome) [5]
• Medication history: Hydralazine, procainamide, isoniazid (drug-induced lupus/pericarditis)

• Male sex, young to middle age (most common demographic) [2]
• Recent viral illness (most common identifiable trigger)
• Post-cardiac surgery or intervention (Dressler syndrome / post-cardiac injury)
• Autoimmune disease (SLE, RA, systemic sclerosis)
• Malignancy (lung, breast, lymphoma, leukemia)
• Tuberculosis exposure (leading cause in endemic areas) [1]
• Uremia / end-stage renal disease
• Immunosuppression / HIV
• Chest radiation therapy
• Risk factors for recurrence: Lack of NSAID response, early corticosteroid use, persistently elevated CRP, severe pericardial LGE on CMR [5]

• Acute coronary syndrome / STEMI — regional ST elevation with reciprocal changes, convex ST morphology, troponin rise with wall motion abnormalities [2-3]
• Myocarditis — chest pain with troponin elevation and LV dysfunction; nonspecific ST-T changes; ~15% have concomitant myopericarditis [2][5]
• Pulmonary embolism — pleuritic pain, dyspnea, tachycardia, right heart strain on ECG [2]
• Aortic dissection — tearing pain radiating to back, pulse/BP differential
• Pneumonia / pleuritis — fever, productive cough, focal findings
• Pneumothorax — sudden onset, unilateral decreased breath sounds
• Costochondritis — reproducible chest wall tenderness
• GERD / esophageal spasm — burning quality, meal-related
• Cardiac tamponade (complication of pericarditis itself)

Key distinguishing features of pericarditis vs. STEMI: diffuse concave ST elevation, PR depression, no reciprocal ST depression (except aVR/V1), ST/T ratio >0.25 in V6 [2-3][9]

• Prior episodes of pericarditis (recurrence rate 15–30% after first episode, up to 50% after first recurrence) [5]
• Autoimmune conditions (SLE, RA, IBD, vasculitis)
• Recent cardiac surgery, MI, or catheterization
• Malignancy (especially thoracic)
• CKD/ESRD (uremic pericarditis)
• Prior chest radiation
• Hypothyroidism (myxedema pericarditis — rare)

• Pericardial friction rub: High-pitched, scratchy, triphasic (atrial systole, ventricular systole, early diastole); best heard with diaphragm at left lower sternal border with patient leaning forward; present in <30% of cases and may be transient [1-2]
• Vital signs: Sinus tachycardia, low-grade fever common; high fever (>38.5°C) is a red flag [3]
• Pulsus paradoxus (>10 mmHg drop in SBP with inspiration) — suggests tamponade [3]
• JVD, muffled heart sounds, hypotension (Beck's triad — tamponade)
• Kussmaul sign (JVP rise with inspiration — constrictive physiology)
• Assess for signs of systemic disease: joint swelling, rashes, lymphadenopathy

Initial workup (all patients)

• CRP (elevated in ~78%; key for monitoring treatment response and guiding taper) [1]
• ESR
• CBC with differential (neutrophilic leukocytosis supports inflammatory phenotype) [1]
• Troponin (elevated in ~30%; if elevated without LV dysfunction = myopericarditis, same management; not a negative prognostic marker) [1]
• BMP (baseline renal function before NSAIDs; rule out uremia)
• BNP/NT-proBNP (generally normal in isolated pericarditis; elevated suggests myocardial involvement or HF)

Selective/high-risk workup

• ANA — only if clinical suspicion for autoimmune disease (low-level titers are nonspecific) [1]
• TB testing (PPD/IGRA) — if risk factors present [1]
• Blood cultures — if bacterial pericarditis suspected
• HIV testing — if risk factors present
• TSH — if hypothyroidism suspected

Monitoring: Serial CRP to guide NSAID taper and detect recurrence [5]

First-line

• Transthoracic echocardiography (TTE) — recommended in all patients; evaluates effusion size, tamponade physiology, LV function, constrictive features [1][5]
• Chest X-ray — evaluate for cardiomegaly (effusion >300 mL), pulmonary pathology, malignancy, TB [1]
• Point-of-care ultrasound (POCUS) — can rapidly identify hemodynamically significant effusion with RV diastolic collapse in the ED [1]

Second-line

• Cardiac MRI (CMR) — recommended for complicated, recurrent, or indeterminate cases; identifies pericardial LGE (inflammation), edema, thickening, and myocardial involvement [5][10]
• Cardiac CT — preferred for pericardial calcification (constrictive pericarditis); not recommended for routine assessment [5]

When imaging is unnecessary: Routine cardiac CT is not recommended for uncomplicated acute pericarditis [5]

• Pericardiocentesis — indicated for tamponade, suspected bacterial/TB/malignant effusion; fluid sent for cell count, Gram stain, culture, cytology, and AFB. Light criteria should NOT be applied to pericardial fluid [1]
• ST/T ratio in lead V6: >0.25 favors pericarditis over early repolarization [2]
• Spodick sign: Downsloping TP segment — suggestive but not pathognomonic

ECG changes occur in 25–60% of cases and evolve through 4 classic stages: [1-2][4]

• Stage I (acute): Diffuse concave ST-segment elevation + PR-segment depression (most prominent in leads II, aVF, V3–V6); reciprocal ST depression and PR elevation in aVR
• Stage II: ST segments normalize, T waves flatten
• Stage III: Diffuse T-wave inversions
• Stage IV: ECG normalizes

Key distinguishing features from STEMI

• Diffuse (not territorial) ST elevation
• Concave ("saddleback") ST morphology vs. convex in STEMI
• No reciprocal ST depression (except aVR/V1)
• PR-segment depression (uncommon in STEMI)
• No pathologic Q waves
• ST/T ratio >0.25 in V6 [2][9]

Other ECG findings: Sinus tachycardia; ~4% present with atrial fibrillation/flutter; low voltage or electrical alternans if large effusion [1]

The following figure illustrates the morphological differences between ST elevation in STEMI vs. pericarditis:

• Epidemiology: ~4.4% of nonischemic chest pain in the ED; most common in men aged 16–65 [1-2]
• Etiology: Idiopathic/viral (80–90%); post-cardiac injury; autoimmune; TB (endemic areas); malignancy; uremia; drug-induced [1]
• Phenotypes: Inflammatory (80–90%, elevated CRP) vs. noninflammatory (10–20%, often autoimmune-associated) [5]
• Complications: Recurrence (15–30%), cardiac tamponade (<3%), constrictive pericarditis (<0.5%) [1]
• Concomitant myocarditis (~15%) — elevated troponin ± LV dysfunction [5]
• Prognosis: Benign in 70–85% with appropriate treatment; recurrence risk increases to 50% after first recurrence [1][5]

Initial stabilization

• ABCs, IV access, continuous monitoring if hemodynamically unstable
• Emergent pericardiocentesis for tamponade

Pharmacotherapy (first episode)

• Ibuprofen 600–800 mg PO q8h + Colchicine 0.5 mg BID (or 0.5 mg daily if ≤70 kg) [1]
• PPI for gastroprotection
• Taper NSAIDs by 200–400 mg every 2–4 weeks once pain resolves and CRP normalizes [6]
• Continue colchicine for 3 months (first episode) [1]

Exercise restriction: ≥1 month, keeping maximal heart rate <100 bpm until clinical remission [5]

Refractory/recurrent

• Corticosteroids (prednisone 0.2–0.5 mg/kg/day) if NSAID/colchicine failure [5]
• IL-1 blockers (anakinra, rilonacept) for multiple recurrences with inflammatory phenotype refractory to colchicine/steroids [8]

The following treatment algorithm summarizes the stepwise approach:

Discharge criteria (low-risk, outpatient management)

• No major or minor risk factors
• Responsive to initial NSAID therapy
• Small or no pericardial effusion
• Hemodynamically stable
• Reliable follow-up available

Admission criteria: [1][5]

• Fever >38°C
• Subacute course (insidious onset)
• Large pericardial effusion (>2.0 cm) or tamponade
• Failure to respond to NSAIDs after 1 week
• Suspected malignancy or bacterial etiology
• Concomitant myocarditis with LV dysfunction
• Oral anticoagulant use (risk of hemorrhagic effusion)
• Immunodeficiency
• Recent chest trauma

Specialist consultation triggers

• Cardiology: tamponade, large effusion, myopericarditis, recurrent disease, constrictive physiology
• Rheumatology: suspected autoimmune etiology
• Infectious disease: TB or bacterial pericarditis
• Cardiothoracic surgery: refractory constrictive pericarditis requiring pericardiectomy

Follow-up timing

• 1–2 weeks after ED discharge for clinical reassessment and repeat CRP [5]
• Serial CRP to guide NSAID taper — do not taper until CRP normalizes
• Repeat echocardiography if effusion was present at diagnosis
• Follow-up at completion of colchicine course (3 months for first episode)

Return precautions — instruct patients to return immediately for:

• Worsening chest pain unresponsive to medications
• New or worsening dyspnea, orthopnea
• Lightheadedness, syncope, or near-syncope
• Fever >38°C
• Leg swelling or new edema

Patient counseling

• Exercise restriction for ≥1 month (no vigorous activity; keep HR <100 bpm) [5]
• Take medications as prescribed; do not stop colchicine early (reduces recurrence by ~50%) [1]
• Avoid NSAIDs on empty stomach; take with food
• Expected recovery: most cases resolve within 1–2 weeks of treatment, but full course of colchicine is essential to prevent recurrence

1. Diagnosis, Risk Stratification, and Treatment of Pericarditis: A Review. — Cremer PC, Klein AL, Imazio M. The Journal of the American Medical Association. 2024.

2. Acute Pericarditis: Rapid Evidence Review. — Peterson TA, Turner SP, Dolezal KA. American Family Physician. 2024.

3. Acute Pericarditis. — LeWinter MM. The New England Journal of Medicine. 2014.

4. Evaluation and Treatment of Pericarditis: A Systematic Review. — Imazio M, Gaita F, LeWinter M. The Journal of the American Medical Association. 2015.

5. 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. — Wang TKM, Klein AL, Cremer PC, et al. Journal of the American College of Cardiology. 2025.

6. Recurrent Pericarditis and Paradigm Shift in Cardiovascular Imaging and Targeted Therapeutics. — Karmali R, Kafil TS, Bayat A, et al. JACC. Advances. 2024.

7. Advances in Imaging and Targeted Therapies for Recurrent Pericarditis: A Review. — Kumar S, Khubber S, Reyaldeen R, et al. JAMA Cardiology. 2022.

8. Inflammation and Cardiovascular Disease: 2025 ACC Scientific Statement: A Report of the American College of Cardiology. — Mensah GA, Arnold N, Prabhu SD, Ridker PM, Welty FK. Journal of the American College of Cardiology. 2025.

9. Fourth Universal Definition of Myocardial Infarction (2018). — Thygesen K, Alpert JS, Jaffe AS, et al. Journal of the American College of Cardiology. 2018.

10. 2021 AHA/­ACC/­ASE/­CHEST/­SAEM/­SCCT/­SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/­American Heart Association Joint Committee on Clinical Practice Guidelines. — Gulati M, Levy PD, Mukherjee D, et al. Journal of the American College of Cardiology. 2021.

11. Electrocardiographic Differential Diagnosis of ST Segment Elevation. — Megan Starling, William J. Brady The Electrocardiagram in Emergency and Acute Care. 2023.

12. Management of Acute and Recurrent Pericarditis: JACC State-of-the-Art Review. — Chiabrando JG, Bonaventura A, Vecchié A, et al. Journal of the American College of Cardiology. 2020.