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Acute Pericarditis

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Overview

Pericarditis is the inflammation of the pericardium and it is described as acute if its onset is within the last 4-6 weeks. Effusions in the pericardial space can lead to cardiac tamponade, a life-threatening complication of acute pericarditis.

Dressler’s syndrome

Dressler’s syndrome is thought to be an autoimmune response to the pericardium after myocardial infarction. It is a post-myocardial infarction pericarditis that usually happens 1-6 weeks after the myocardial infarction. In some cases, it may be delayed for as long as 3 months. 

Epidemiology

  • Peak incidence between 20-50 years
  • More common in men

Risk Factors

Presentation

Chest pain is the most common presenting complaint:

  • Usually acute
  • Described as sharp
  • Pleuritic – worse with inspiration
  • It is usually relieved leaning forward or sitting up
  • It is usually worsened lying down

Other features:

  • Tachycardia
  • Tachypnoea
  • Pericardial friction rub on auscultation
  • Fever
  • Myalgias

Differential Diagnoses

Myocardial ischaemia or infarction

  • Chest pain is more “heavy” and “squeezing” and pressure-like and does not typically vary with position
  • Pericardial friction rub absent unless there is associated pericarditis
  • ECG shows signs of myocardial infarction or ischaemia

Pulmonary embolism

  • Pain is acute in onset and pleuritic but does not vary with posture
  • Pericardial friction rub is rarely present
  • ECGs usually only show sinus tachycardia

Pneumonia

  • Cough and fever present
  • Chest pain does not typically vary with position
  • ECG changes are absent

Pneumothorax

  • Examination shows an absence of breath sounds usually laterally
  • Chest pain does not typically vary with position
  • Tracheal deviation may be present if tension pneumothorax is present
  • Chest x-ray shows lung collapse

Costochondritis

  • Tenderness is reproducible on palpating the costochondral junctions
  • Pain worsened when moving the trunk
  • ECG normal

Investigations

All patients

  • ECG:
    • May show global saddle-shaped ST-elevation with PR depression
    • PR depression is most specific for pericarditis
  • Cardiac troponins:
    • May be raised in pericarditis
    • Also used to look for acute coronary syndrome
  • Echocardiography – an essential investigation:
    • Detects pericardial effusions, which if large enough, can cause cardiac tamponade, a life-threatening complication 
  • Pericardiocentesis:
    • If suspected cardiac tamponade
    • Aspirates can be sent for microscopy and cytology to identify underlying causes

Other investigations include:

  • Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP):
    • Non-specific markers of inflammation, may be elevated
  • Urea and electrolytes (U&Es):
    • Elevated urea levels can cause pericarditis
  • Full blood count (FBC):
    • Leukocytosis may be present in acute pericarditis and may also suggest infection
  • Liver function tests (LFTs):
    • If cardiac tamponade occurs there may be liver congestion which can cause deranged LFTs
  • D-dimer:
  • Chest x-ray:
    • To screen for other chest pathologies (such as pneumothorax)
    • Generally normal

Management

All patients

  • Treat underlying cause
  • 1st line: NSAIDs + proton pump inhibitors + colchicine
  • Corticosteroids are used under specialist guidance if:
    • Infection has been ruled out and NSAIDs and colchicine fail or
    • There is a specific indication e.g. autoimmune diseases like systemic lupus erythematosus – in this case, corticosteroids and colchicine are used

Monitoring

  • Patients with high-risk features should be admitted to the hospital. Those without high-risk features may be managed as an outpatient and followed up regularly. These high-risk features are:
    • Major:
      • High fever >38°C
      • Onset is over several days without clear-cut acute onset
      • Large pericardial effusion
      • Cardiac tamponade
      • Failure to respond to 7 days of NSAIDs
    • Minor:
      • Pericarditis associated with myocarditis
      • Immunosuppression
      • Trauma
      • Oral anticoagulation therapy
  • If there is suspicion of constrictive pericarditis or pericardial effusions, echocardiograms, CT scans, or MRI scans may be needed.

Patient Advice

  • Patients should avoid strenuous physical activity until symptoms and the CRP have normalised

Complications

  • Pericardial effusion and potential cardiac tamponade
  • Chronic constrictive pericarditis – relatively rare
    • In the healing process, some of the pericardium may be replaced with scar tissue which can interfere with ventricular filling

Prognosis

  • Major risk factors mentioned above are associated with a worse prognosis
  • Acute idiopathic pericarditis is generally self-limiting in 70-90% of patients
  • With treatment, symptoms and inflammatory markers generally resolve after 2 weeks

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