Pericarditis

Essentials

• Pericarditis is a common cause of chest pain in patients presenting out of office hours.
• Hospitalisation is usually indicated in the presence of
  • fever
  • low blood pressure and high heart rate
  • elevated venous pressure
  • a large pericardial effusion
  • immunosuppression.
• Most cases of pericarditis may be managed at home.
• Echocardiography will assist diagnosis and management planning.
• First-line pharmaceutical treatment usually consists of an NSAID and colchicine.
• Frequent recurrences of acute pericarditis are possible, in which case the management usually involves colchicine for six months.

Aetiology

• Infection (viral, bacterial or fungal)
• Active connective tissue disorder (rheumatoid arthritis, SLE, systemic scleroderma)
• Malignancy (usually associated with metastasis)
• Severe renal failure (uraemia)
• Pericardial injury
  • Post-myocardial infarction (Dressler's syndrome)
  • Post-pericardiotomy
  • Cardiac trauma
• Following a cardiac procedure
  • Angioplasty
  • Insertion of a pacemaker
  • Ablation therapy for arrhythmia
• Drug reaction (certain antimicrobials, cytotoxic drugs)
• Sequela of radiotherapy targeting the chest and cardiac region
• Idiopathic (the most common cause)

Signs and symptoms

• Chest pain is the most common symptom of acute pericarditis.
• The pain is sharp and stabbing and does not usually radiate.
• A pericardial friction rub can be heard in the early phase and is usually position dependent.
  • The friction rub is usually biphasic, systolic-diastolic, often only audible during the inspiratory phase of respiration and may sound similar to rubbing sandpaper together.
  • The rub may be absent in the presence of a large pericardial effusion.
• Filled jugular veins, increased jugular venous pressure
• Symptoms associated with an infection

Investigations

• Chest x-ray
  • Often normal
  • The heart silhouette may appear enlarged if pericardial effusion is large.
  • Changes in the lung parenchyma are possible in infections.
• ECG
  • Phasically alteringST-T changes resulting from myocarditis
  • Low-voltage if a large accumulation of pericardial fluid is present
  • Tachycardia
• Laboratory tests
  • CRP elevated in > 80% of patients
  • Mild or moderate leukocytosis, elevated SR
  • The concentration of troponin (TnT, Tnl) increases if pericarditis is accompanied by myocarditis (myopericarditis).
• Echocardiography http://www.dynamed.com/condition/pericardial-effusion-and-tamponade#ECHOCARDIOGRAPHY
  • The key investigation
  • Pericardial effusion
    • An abnormal finding is defined as a fluid depth > 5 mm during a diastole.
    • A moderate effusion is defined as a fluid depth of 10-20 mm.
    • A large effusion is defined as a fluid depth > 20 mm.

Differential diagnosis

• Myocardial infarction must be borne in mind as a possible alternative diagnosis.
  • The severe pain of pericarditis may resemble that of myocardial infarction.
  • However, the ECG changes are more diffuse and disproportionate to the clinical symptoms.
    • ST changes are seen in several leads.
    • T wave changes are common.
  • A patient with pericarditis usually presents with generalised symptoms of an infection.

Treatment

Prognosis

• Symptoms are mild in the majority of cases and the prognosis is good (viral infection).
• Bacterial (purulent) pericarditis is life threatening http://www.dynamed.com/condition/acute-and-recurrent-pericarditis#FOR_PATIENTS_WITH_PURULENT_PERICARDITIS.
• Cardiac tamponade requires immediate management http://www.dynamed.com/condition/pericardial-effusion-and-tamponade#PERICARDIOCENTESIS.
• Recurrent pericarditis may in some cases lead to the development of a constriction.