Treatment of Pericarditis with Depressed PR Interval
The presence of a depressed PR interval on ECG is a typical finding in acute pericarditis and does not alter the standard treatment approach—first-line therapy remains high-dose NSAIDs (aspirin 750-1000 mg every 8 hours or ibuprofen 600 mg every 8 hours) combined with colchicine for 3 months. 1, 2
Understanding the PR Depression
The depressed PR segment is a characteristic ECG finding in acute pericarditis, typically appearing in Stage I alongside ST elevation. 1 This finding reflects:
- Atrial involvement in the inflammatory process, distinguishing pericarditis from myocardial infarction 1
- PR depression is most prominent in leads I, II, aVL, aVF, and V3-V6, while PR elevation occurs in aVR 1
- This ECG pattern does not indicate worse prognosis or require treatment modification 1
First-Line Treatment Protocol
NSAIDs with Gastroprotection
Aspirin or ibuprofen are Class I, Level A recommendations as initial therapy: 1, 2
- Aspirin: 750-1000 mg every 8 hours for 1-2 weeks 1, 2
- Ibuprofen: 600 mg every 8 hours for 1-2 weeks (preferred for better coronary flow and fewer side effects) 1
- Mandatory gastroprotection must be provided 1, 2
- Avoid indomethacin in elderly patients due to coronary flow reduction 1
Colchicine as Mandatory Adjunct
Colchicine is a Class I, Level A recommendation to be added to NSAIDs, not used as monotherapy: 1, 2
- Weight-adjusted dosing: 0.5 mg once daily if <70 kg, or 0.5 mg twice daily if ≥70 kg 1, 2
- Duration: 3 months minimum 1, 2
- Reduces recurrence risk from 37.5% to 16.7% (absolute risk reduction 20.8%) 3
Treatment Duration and Tapering
Continue therapy until symptoms resolve AND CRP normalizes: 1, 2
- NSAIDs: Typically 1-2 weeks, then taper by 250-500 mg (aspirin) or 200-400 mg (ibuprofen) every 1-2 weeks 1, 2
- Monitor CRP levels to guide treatment length and assess response 1, 2
- Premature tapering (within 1 month) increases recurrence risk 4
Second-Line Treatment (Only After First-Line Failure)
Corticosteroids are Class IIa, Level C recommendations and should be avoided as initial therapy due to increased risk of chronicity and recurrence: 1, 2
Indications for Corticosteroids
- Contraindication or failure of aspirin/NSAIDs and colchicine 1, 2
- Autoimmune disease or uremic pericarditis 1
- After infectious causes excluded 1
- Patients on anticoagulation where NSAIDs pose high bleeding risk 5
Corticosteroid Dosing
Use low to moderate doses only: 1, 2, 5
- Prednisone 0.2-0.5 mg/kg/day (NOT 1.0 mg/kg/day) 1, 2, 5
- Always combine with colchicine when using corticosteroids 1, 5
- Slow tapering schedule based on initial dose: 5
50 mg: Decrease by 10 mg every 1-2 weeks
- 50-25 mg: Decrease by 5-10 mg every 1-2 weeks
- 25-15 mg: Decrease by 2.5 mg every 2-4 weeks
- <15 mg: Decrease by 1.25-2.5 mg every 2-6 weeks
Risk Stratification and Monitoring
Hospitalization is warranted to determine etiology and observe for tamponade: 1
- Low-risk cases: Outpatient management with NSAIDs and colchicine 1, 2
- Monitor response after 1 week using symptoms and CRP 1, 5
- Exercise restriction until symptoms resolve and CRP, ECG, and echocardiogram normalize 1, 2
- Athletes require 3 months minimum restriction from competitive sports 1, 2
Critical Pitfalls to Avoid
Inadequate treatment of the first episode is the most common cause of recurrence: 2
- Never use corticosteroids first-line unless specific contraindications exist—they increase recurrence risk from 15-30% to 50% 2, 6, 3
- Do not taper before CRP normalizes—this promotes recurrence 1, 2
- Do not omit colchicine—it is essential for preventing recurrence 1, 2, 3
- Ensure full 3-month colchicine course—shorter durations increase recurrence 1, 2
Refractory Cases
For patients failing NSAIDs, colchicine, and corticosteroids: 5, 6, 3, 4