II. Epidemiology
- Post-MI Pericarditis Incidence has fallen with the advent of cardiac interventions for Acute Coronary Syndrome
III. Pathophysiology
- Post-MI Pericarditis arises from an immune response to Antigens (antimyosin, antiheart) from injured Myocardium
- Pericarditis represents one part of a Constellation of post-MI syndrome complications
IV. Types
- Early Post-MI Pericarditis (1 to 6% of acute MI patients)
- Onset within the first few days of Myocardial Infarction
- Arises from localized inflammation from Myocardium injured by infarction
- Typically benign course and resolves spontaneously
- Late Post-MI Pericarditis or Dressler Syndrome (<1% of MI patients)
- Onset weeks to months after Myocardial Infarction
- Abnormal, persistent inflammation that extends beyond the time of MI recovery
- Typically symptomatic with a more complicated course (Pericardial Effusions or Cardiac Tamponade)
V. Risk Factors
- Large Myocardial Infarction
- Delayed MI presentation
- Failed percutaneous intervention
VI. Labs
- Serum Troponin
- Elevations from acute MI will be difficult to distinguish from Myocarditis
- Inflammatory markers (e.g. C-RP, ESR, Leukocytosis)
- Often elevated in both Myocardial Infarction and Pericarditis
VII. Diagnostics
- See EKG in Pericarditis
- See EKG in Acute Coronary Syndrome
-
Electrocardiogram
- May be difficult to distinguish post-MI and reperfusion findings from Pericarditis related EKG changes
VIII. Imaging
-
Echocardiogram
- Identifies Pericardial Effusion and Cardiac Tamponade
-
Cardiac MRI
- Identifies findings consistent with Pericarditis
- Pericardium thickening or edema
- Pericardium delayed clearance of contrast
- Identifies Myocardial Infarction (MI) complications
- Extent and timing of MI
- Ventricular Scar
- Cardiomyopathy
- Ventricular aneurysm
- Identifies findings consistent with Pericarditis
IX. Findings
- See Pericarditis
- Similar Pericarditis symptoms and signs, in the context of recent Myocardial Infarction
X. Management
- Optimize Management of Acute Coronary Syndrome
- Acute MI management (e.g. reperfusion) takes precedence over Pericarditis management
-
Aspirin
- First-line therapy for Post-Myocardial Infarction Pericarditis (or Pericarditis and known Coronary Artery Disease)
- Aspirin 650-1000 mg every 6-8 hours for 7-10 days and then tapered over 4 weeks
-
Colchicine
- Indicated in Pericarditis refractory to Aspirin
- See Colchicine for adverse effects and lab monitoring
- Dosing
- Start 1-2 mg on day 1 and then 0.5 to 1 mg/day for 3 months (divided dosing)
- Weight > 70 kg (154 lb): 0.5 mg twice daily
- Weight <70 kg (154 lb): 0.5 mg once daily
- Colchicine weaned after CRP drops to <3
- Medications to Avoid In Post-MI Pericarditis (contrast with non-MI related Pericarditis)
- Avoid NSAIDs
- Delay myocardial healing
- Indomethacin decreases coronary Blood Flow
- Avoid Corticosteroids
- Delay myocardial healing and weaken the Myocardium
- Risk of myocardial rupture or ventricular aneurysm
- Avoid NSAIDs
XI. Complications
- See Pericarditis
- Cardiac Tamponade
- Constrictive Pericarditis
- Recurrent Post-MI Pericarditis (10-15% of cases)
- Differentiate from recurrent Acute Coronary Syndrome
XII. References
- Klasek and Alblaihed (2023) Crit Dec Emerg Med 37(6): 4-11
- Verma (2020) Curr Cardiol Rep 22(10): 127 [PubMed]