pericarditis

see also:

• the adult patient with chest pain in the ED
• myocarditis
• Paient UK information sheet on pericarditis
• 2025 ESC Guidelines for the management of myocarditis and pericarditis: Developed by the task force for the management of myocarditis and pericarditis of the European Society of Cardiology (ESC)

• acute “viral”/“idiopathic” pericarditis has generally a brief and benign course after empiric treatment by aspirin (acetylsalicylic acid) or non-steroidal anti-inflammatory drugs (NSAIDs), and routine hospitalization of most patients may be unnecessary.
• complications develop in ~20% ¹⁾:
  • recurrent pericarditis 18%
    • risk factors include:
      • lack of response to non-steroidal anti-inflammatory drugs (NSAIDs)
      • need for corticosteroid therapy
      • inappropriate pericardiotomy
      • creation of a pericardial window
  • cardiac tamponade <5%
  • constrictive pericarditis 1.5%
• NB post-infarct pericarditis is not included in this entity on this page
• The inflammatory myo-pericarditis syndrome (IMPS) is a newly introduced umbrella term encompassing the full spectrum of inflammatory myocardial (myocarditis) and pericardial (pericarditis) diseases, including those overlapping both conditions.

• “viral” or “idiopathic” (>80%)
• post-infarction regional pericarditis (PIRP)
  • occurs in the days following transmural STEMIs as the epicardium is involved with subsequent inflammation of the pericardium
  • this results in either:
    • persistent ST elevation with upright T waves > 48hrs post-STEMI
    • gradual reversion of inverted T waves to upright Twaves within 48-72hrs post-STEMI in association with well formed Q waves
  • these patients are at risk of:
    • myocardial rupture causing cardiac tamponade or, if it is a septal AMI, an acute VSD with L-to-R shunt and APO/cardiogenic shock
    • LV aneurysm and mural thrombus
  • see http://hqmeded-ecg.blogspot.com.au/2014/07/subacute-anteroseptal-stemi-with.html
• auto-immune (7%)
• neoplastic (5%)
• tuberculosis (TB) (4%)
• purulent (<1%)
• chylopericardium is a rare disorder that may be primary (ie, idiopathic) or, more often, secondary to injury to the thoracic duct such as in trauma or post-operative
  • chylothorax, with or without chylopericardium, is much more common than isolated chylopericardium. Most cases are nontraumatic, with the major cause being malignancy, particularly lymphoma.

• anterior chest pain
  • typically sharp, worse on inspiration and on lying down
  • may be dull
  • may radiate to shoulders
• may have a pericardial friction rub
  • highly specific but low sensitivity as they are quite variable from hour to hour, and may not be heard if there is an effusion
  • superficial scratchy or squeaking quality that is best heard with firm pressure of the diaphragm of the stethoscope, with patient leaning forwards or resting on elbows and knees so that contact between visceral and parietal pericardium is maximised
  • ask patient to stop breathing to differentiate from a pleural rub
• may have a pericardial effusion
  • 40% do NOT have a pericardial effusion
  • of the remainder, ~80% have a small effusion and 10% have a moderate effusion
  • 5% develop life threatening cardiac tamponade²⁾
• may have recent or current viral infection
• 15% also have evidence of viral myocarditis hence called myopericarditis but this is usually benign ³⁾
  • diagnosed by either:
    • raised troponin (does not appear to have any prognostic value)
    • impaired LV ejection fraction on echo
  • risk factors include:
    • arrhythmias (odds ratio (OR) = 17.6, 95% confidence interval (CI) 5.7 to 54.1; p<0.001)
    • male gender (OR = 6.4, 95% CI 2.3 to 18.4; p = 0.01)
    • age <40 years (OR = 6.1, 95% CI 2.2 to 16.9; p = 0.01)
    • ST elevation (OR = 5.4, 95% CI 1.4 to 20.5; p = 0.013)
    • recent febrile syndrome (OR = 2.8, 95% CI 1.1 to 7.7; p = 0.044)

• generally required to have at least 2 of the 4 features:
  • pericardial chest pain
  • pericardial friction rubs
  • new ECG changes of widespread ST-segment elevation or PR depression (< 60% have these)
  • new or worsening pericardial effusion (<60% have this)

• 1st described by Spodick et al
• less than half of all patients evolve through all stages
• the evolution of ECG changes in acute pericarditis is heterogeneous with a significant variation between patients
• a normal ECG does NOT exclude pericarditis as it may be normal at initial presentation and at 12-48hrs after that!
• ECG changes are dynamic and can evolve rapidly during the disease course and are influenced by several factors
• the classic ECG patterns of widespread ST-segment elevation or PR depression can be seen in less than 60% of patients, and often only at the initial phase (stage 1) of the acute pericarditis, and are more common in younger male patients, particularly in the presence of concomitant involvement of the adjacent myocardium (myopericarditis) ⁴⁾
• ECG changes are due to inflammation of the epicardium
• tachycardia may be the only ECG finding if ST elevation has resolved & T waves remain normal
• stage 1:
  • lasts hrs-days
  • diffuse PR depression leads I,II,III,aVL, aVF, V2-6 (esp. II, aVF, V4-6) with reciprocal elevation in aVR, V1
    • NB. PR depression may also occur in benign repolarisation (but is usually < 0.8mm and there is no ST depression in V1 and ST:T height ratio is < 25% in benign repolarisation) and in AMIs involving the atrium
  • widespread ST elevation, 2-5mm concave & upward in leads I, II, III, aVF & V2-5 (may be confined to II, V5,6 where it tends to be greatest) and reciprocal depression if present, only in aVR & V1
    • ST elevation limited to the anterior leads is more likely to be early repolarization than pericarditis
  • PR changes often co-exist with ST changes but may be isolated and may precede ST changes
  • slight elevation of PR segment in aVR
  • if T-wave inversion antedates pericarditis, concomitant ST elevation and T-wave inversion may be seen once pericarditis develops
• stage 2:
  • a few days later
  • ST & PR segments become isoelectric with flattened or upright T waves
  • HOWEVER, 40% of patients develop a notched or biphasic positive-negative T wave before full return of the ST segment to the baseline
• stage 3:
  • diffuse T wave inversion
• stage 4:
  • lasts days - weeks
  • T waves normalise, but rarely, remain normal

• PR depression is suggestive of pericarditis (but can occur in STEMI)
• ST elevation occurs in BOTH limb leads and precordial leads in pericarditis whereas 50% with early repolarization have no ST deviations in the limb leads
• PR and ST/T wave evolutionary changes do not occur in early repolarization
• ratio of ST elevation to T wave amplitude in lead V6 > 0.24 indicates pericarditis ⁵⁾
• presence of Spodick sign suggests pericarditis
  • downward sloping T-P segment esp. seen in II and lateral leads but only in 30% of patients (but also occurs in 5% of those with STEMI) - https://litfl.com/spodick-sign/

• usually related to the presence of either:
  • pericardial effusion
    • ⇒ low voltage amplitude in all leads
    • ⇒ electrical alternans may occur with large effusions or tamponade
  • constrictive pericarditis
    • ⇒ low voltage amplitude in all leads but no electrical alternans
    • ⇒ left atrial abnormalities
• NB. myxoedema also causes low voltages but usually bradycardia as well whereas pericarditis tends to cause tachycardia

• fever >38 degrees C (HR 3.56, 95% CI 1.82 to 6.95; P<0.001)
• subacute onset (HR 3.97, 95% CI 1.66 to 9.50; P=0.002)
• immunosuppression
• trauma
• oral anticoagulant therapy
• myopericarditis
• large pericardial effusion (HR 2.15, 95% CI 1.09 to 4.23; P=0.026)
• cardiac tamponade
• raised troponin
• failure to respond to aspirin or NSAID Rx (9% develop constriction vs 0.5% of those who respond to aspirin, HR 2.50, 95% CI 1.28 to 4.91; P=0.008) )^{6) 7)}

• exclude other potential causes of chest pain if Dx is not clear
• CXR to help exclude a large effusion or evidence of LVF
• ECG
• FBE, U&E, troponin, CRP
• bedside Echo if available to assess for pericardial fluid etc
• serology is NOT indicated other than if HIV / AIDS, hepatitis C virus or lyme disease is possible
• consider need to test for tuberculosis (TB) and auto-immune disorders (eg. consider ANA)
• if low risk:
  • then discharge home on 1st line Rx:
    • high dose aspirin (acetylsalicylic acid), or non-steroidal anti-inflammatory drugs (NSAIDs) if no C/I
      • consider avoiding or using lower dose non-steroidal anti-inflammatory drugs (NSAIDs) if myocarditis is also present as animal models of myocarditis, NSAID are not effective and may actually enhance the myocarditic process and increase mortality⁸⁾
      • avoid non-steroidal anti-inflammatory drugs (NSAIDs) in post-AMI pericarditis - high dose aspirin is preferred
      • if C/I to NSAIDs such as pregnancy, or if patient needs steroids for other conditions, then can use short courses of corticosteroids instead of NSAIDs but steroids may increase rate of recurrence
    • PLUS colchicine 500mcg bd to reduce rate of recurrence
    • PLUS proton pump inhibitors (PPIs)
  • consensus is that all patients should have an early echocardiogram
    • early OP echo within 2 weeks if echo cannot be done that day
  • warn patient of features of tamponade which would mandate urgent reassessment, although tamponade is very rare in low risk patients ⁹⁾
  • warn patients to restrict exercise until remission and for at least 1 month
  • pregnant patient
    • Effusions during pregnancy are typically benign, mild or moderate, and well tolerated, with spontaneous resolution after delivery, and no specific treatment is required in such cases. However, PEff may be associated with pre-eclampsia.¹⁰⁾
    • high-dose aspirin or NSAIDs, such as ibuprofen and indomethacin, can be used up to the 20th week of gestation¹¹⁾
    • corticosteroids at the minimal effective dose can be given in patients with active pericarditis throughout pregnancy along with NSAIDs and in selected cases colchicine ¹²⁾
    • azathioprine and IVIG are compatible with pregnancy and breastfeeding
    • all these medications, apart from high-dose aspirin, may be used during lactation ¹³⁾
    • use of IL-1 blockers during pregnancy is controversial
• if mod-high risk patient
  • admit
  • urgent echo
  • emergency therapeutic pericardiocentesis if cardiac tamponade is present
  • diagnostic pericardiocentesis should be considered if:
    • suspect a malignant, TB, or another bacterial etiology, or,
    • in patients with an effusion refractory to medical therapy
  • multimodal imaging for those with suspected constrictive pericarditis
• consider OP cardiac MRI if there is:
  • myocarditis to assess oedema, ischaemia, necrosis/fibrosis/scarring, and at 6 months to help risk stratify and advise on exercise
  • unclear diagnosis of pericarditis to assess pericardial thickening, oedema, late gadolinium enhancement (LGE), or to assess persistence of disease in follow up
• those with post-cardiac injury syndrome (PCIS):
  • high dose aspirin (acetylsalicylic acid) is preferred over NSAIDs for post-myocardial infarction pericarditis and in patients already on anti-platelet Rx
  • those with refractory PCIS should be considered for anti-IL-1 agents such as anakinra or rilonacept to reduce risk of progression to constrictive disease
• additional considerations for those with recurrent pericarditis:
  • patients with recurrent pericarditis despite high dose aspirin (or NSAIDs) plus [[colchicine] may benefit from anti-IL-1 agents such as anakinra or rilonacept
  • obtain FH including pedigrees to provide clues on aetiology, inheritance pattern, and identify relatives at risk
  • pre-conception counseling for women to assess disease activity and review Rx