Pericarditis

Pericarditis is inflammation of the pericardium that may be acute or chronic. Acute pericarditis is most commonly caused by viral infection; however, a number of conditions can cause an inflammatory response in the pericardium. Acute inflammation typically manifests with fever, pleuritic chest pain, and a pericardial friction rub on auscultation. The diagnosis is established based on clinical findings, although diffuse ST segment elevations on ECG and imaging may support the diagnosis. Acute pericarditis is usually self-limited, lasting days to weeks, and is therefore managed symptomatically. If pericarditis lasts longer than three months, it is described as chronic pericarditis. Chronic pericarditis may either be constrictive or effusive-constrictive. Constrictive pericarditis is characterized by thickening and rigidity of the pericardium, resulting in both backward and forward failure. Patients typically present with fatigue, jugular vein distention, peripheral edema, and a characteristic pericardial knock on auscultation, which is caused by a sudden stop in ventricular diastolic filling. Effusive-constrictive pericarditis is characterized by a thickened pericardium with an effusion; this can lead to cardiac tamponade. It may manifest with symptoms similar to constrictive pericarditis, symptoms of pericardial effusion, or cardiac tamponade. In both constrictive and effusive-constrictive pericarditis, imaging is used to confirm the diagnosis. Management consists of treatment of heart failure (e.g., diuretics) and pericardiectomy.

• Acute pericarditis: inflammation of the pericardium that either occurs as an isolated process or with concurrent myocarditis (myopericarditis). ^[1]
  • Perimyocarditis: condition predominantly affecting the myocardium with pericardial involvement
• Transient constrictive pericarditis: constrictive pericarditis that lasts < 3 months
• Chronic pericarditis: inflammation of the pericardium that lasts > 3 months ^[2][3]
  • Constrictive pericarditis is characterized by compromised cardiac function caused by a thickened, rigid, and fibrous pericardium secondary to acute pericarditis.
  • Effusive-constrictive pericarditis: Pericardial effusion occurs in addition to a thickened pericardium, which can lead to tamponade. ^[4]

• Idiopathic
• Infectious
  • Most commonly viral (e.g., coxsackie B virus) ^[5]
  • Bacterial (e.g., Staphylococcus spp., Streptococcus spp., or M. tuberculosis)
  • Fungal
  • Toxoplasmosis
• Myocardial infarction
  • Postinfarction fibrinous pericarditis; : within 1–3 days as an immediate reaction
  • Dressler syndrome; : weeks to months following an acute myocardial infarction
• Postoperative (postpericardiotomy syndrome): blunt or sharp trauma to the pericardium
• Uremia (e.g., due to acute or chronic renal failure)
• Radiation
• Neoplasm (e.g., Hodgkin lymphoma)
• Autoimmune connective tissue diseases (e.g., rheumatoid arthritis, systemic lupus, scleroderma)

Acute pericarditis ^[6]

• Chest pain
  • Pleuritic chest pain
    • Acute, sharp retrosternal pain caused by inflammation of the parietal pleura
    • Typically aggravated by coughing, swallowing, or deep inspiration
    • Other causes of pleuritic chest pain include pulmonary embolism, myocardial infarction, and pneumothorax.
  • Improves on sitting and leaning forward
  • Can radiate to the neck and shoulders (most commonly to the left side)
• Pericardial friction rub: high-pitched scratching on auscultation
  • Indicates friction between the visceral and parietal pericardial tissue ^[7]
  • Best heard over the left sternal border during expiration while the patient is sitting up and leaning forward ^[8]
  • Occurs in atrial and ventricular systole, as well as early diastole ^[9]
  • Present in 85% of patients with acute pericarditis. ^[10]
• Pericardial effusion
  • Faint heart sounds
  • Ewart sign
• Low-grade intermittent fever, tachypnea, dyspnea, nonproductive cough

Chronic pericarditis

Constrictive pericarditis ^[6][5]

• Symptoms of fluid overload (i.e., backward failure)
  • Jugular vein distention, ↑ jugular venous pressure
  • Kussmaul sign
  • Hepatic vein congestion: hepatomegaly, painful liver capsule distention, hepatojugular reflux
  • Peripheral edema; or anasarca, ascites with abdominal discomfort
• Symptoms of reduced cardiac output (i.e., forward failure)
  • Fatigue, dyspnea on exertion
  • Tachycardia
  • Pericardial knock: sudden cessation of ventricular filling during early diastole that is heard best at the left sternal border
  • Pulsus paradoxus: ↓ blood pressure amplitude by at least 10 mm Hg during deep inspiration

Effusive-constrictive pericarditis ^[4]

Effusive-constrictive pericarditis; is characterized by symptoms of chronic constrictive pericarditis, pericardial effusion, or a mixture of both.

• Smaller or slow-growing effusions: Patients may be asymptomatic.
• Large effusions or rapidly growing effusions: symptoms of cardiac tamponade
  • Beck triad
  • Dullness at the left base of the lung due to compression

Acute pericarditis ^[5]

Approach

• Check ECG, TTE to determine if diagnostic criteria are met.
• If TTE is inconclusive, consider CT or cardiac MRI to confirm pericardial inflammation/effusion.
• Determine whether any further diagnostic evaluation is indicated based on suspected etiology (see “Additional diagnostic evaluation” below).

Diagnostic criteria for acute pericarditis ^[4]

At least two of the following four criteria must be present for a diagnosis of acute pericarditis:

1. Characteristic chest pain
2. Pericardial friction rub
3. Typical ECG changes (see below)
4. New or worsening pericardial effusion

ECG

Not all patients go through all stages and manifestations may vary. In particular, pericarditis due to uremia may not involve characteristic ECG changes. ^[11]

• Stage 1: diffuse ST elevations; , ST depression in aVR and V1; , PR segment depression
• Stage 2: ST segment normalizes in ∼ 1 week.
• Stage 3: inverted T waves
• Stage 4: ECG returns to normal baseline (as prior to onset of pericarditis) after weeks to months.

In contrast to myocardial infarction, pericarditis is characterized by a diffuse distribution of ST elevations on ECG.

Imaging ^[4][5]

The goal of imaging is to identify any new pericardial effusion and rule out alternative etiologies.

• Echocardiography
  • Indications: considered first-line to evaluate for pericardial disease ^[4][5]
  • Findings: pericardial effusion may be present, often normal
• Cardiac MRI
  • Indications: Consider if diagnosis is uncertain; preferred imaging modality to assess pericardium. ^[4]
  • Findings
    • Thickened pericardium, pericardial enhancement, pericardial effusion ^[12]
    • May show associated myocarditis ^[12]
• CT scan with IV contrast
  • Indications: Consider if the diagnosis is uncertain.
  • Findings: thickened pericardial layers, pericardial effusion
• Chest x-ray: usually normal; may show an enlarged cardiac silhouette

Laboratory studies

Elevation of inflammatory markers may support the diagnosis of pericarditis but are not considered to be a part of the diagnostic criteria. ^[4]

• CBC: leukocytosis
• ↑ Troponin I
• ↑ ESR
• ↑ CRP
• ↑ Creatinine kinase

Additional diagnostic evaluation

• Pericardiocentesis with pericardial fluid analysis ^[10]
  • Indications: large effusion, tamponade, suspected malignant or purulent pericarditis ^[5]
  • Investigations depend on suspected etiology.
    • Gram stain
    • Bacterial culture
    • Acid-fast bacilli and culture
    • Polymerase chain reaction
    • Cytology
• Additional workup based on suspected etiology
  • Uremic pericarditis: BUN, creatinine, electrolytes
  • Bacterial pericarditis: blood cultures (2 sets)
  • Tuberculous pericarditis: interferon-γ release assay, HIV test
  • Autoimmune pericarditis: ANA, rheumatoid factor

Chronic pericarditis

The diagnostic approach and findings for chronic pericarditis are similar to acute pericarditis but ECG, echocardiography, and imaging findings may vary.

• Additional laboratory studies
  • BNP: normal ^[13]
  • LFT: may show elevated transaminases and low albumin ^[14]
• Investigation of the underlying cause: See “Additional diagnostic evaluation” above.

Constrictive pericarditis ^[6][5]

The diagnosis of constrictive pericarditis is based on characteristic imaging findings (most commonly echocardiography but MRI and CT may be used).

• Echocardiography
  • ↑ Pericardial thickness
  • Abnormal ventricular filling with sudden halt during early diastole
  • Variation in ventricular filling with inspiration
    • Across the tricuspid valve: The velocity of blood flow increases.
    • Across the mitral valve: The velocity of blood flow decreases.
  • Moderate biatrial enlargement ^[15]
  • Excludes right ventricular hypertrophy and cardiomyopathy
• Imaging
  • CT and cardiac MRI
    • Pericardial thickening > 2 mm
    • Calcifications
    • Normal cardiac silhouette
  • Chest x-ray (PA and lateral views) ^[14]
    • Heart size: normal or slightly increased
    • Pericardial calcifications
    • Clear lung fields

• Cardiac catheterization
  • Indications: if noninvasive methods have failed to provide a definitive diagnosis ^[4]
  • Findings ^[16]
    • Similar pressures in the left and right atria and right ventricle at the end of diastole (e.g., “equalization of pressures”)
    • Normal pulmonary artery systolic pressure < 40 mm Hg
    • Mean right arterial pressure > 15 mm Hg
    • Square root sign ^[4]
      • Also known as dip-and-plateau waveform
      • Sudden dip in the right and left ventricular pressure in early diastole followed by a plateau during the last stage of diastole
• ECG
  • No conclusive findings: generalized flat/inverted T waves, low QRS voltage
  • Atrial fibrillation can occur in severe disease. ^[17]

Effusive-constrictive pericarditis

The diagnostic findings of effusive-constrictive pericarditis are similar to those of pericardial effusion, with the exception that in addition to pericardial effusion, pericardial thickening may also be seen. Elevation of right atrial pressures despite pericardiocentesis is strongly suggestive of effusive-constrictive. ^[18]

• Echocardiography, CT, and/or cardiac MRI: pericardial effusion ; pericardial thickening may also be present ^[19][20]
• Pericardiocentesis with cardiac catheterization: right atrial pressure remains persistently elevated after pericardiocentesis. ^[4]
• Other findings consistent with pericardial effusion
  • ECG: Low ECG voltage and electrical alternans may be present.
  • Chest x-ray (PA and lateral views) ^[4][21]
    • PA: may show a globular-shaped heart and sharp cardiophrenic angles
    • Lateral: may show the “fat pad” sign
  • See also “Diagnostics” in pericardial effusion.

The mainstays of therapy include anti-inflammatories to control pain and prevent a recurrence, and treatment of the underlying cause (if found).

Medical therapy

Acute pericarditis is often self-limited; but NSAIDs can alleviate symptoms and prevent a recurrence. Consider anti-inflammatory therapy also for chronic pericarditis (transient constrictive pericarditis may respond). ^[10]

• NSAID therapy
  • Aspirin
  • Ibuprofen
  • Indomethacin
• Consider colchicine in combination with NSAIDs or as a monotherapy. ^[4]
• Consider prednisone only in severe cases or in pericarditis caused by uremia, connective tissue disease, or autoreactivity.
• Gastroprotective therapy (e.g., omeprazole ) in patients at risk for GI bleeding

Additional considerations

• Treat any known underlying causes.
  • Antibiotics for bacterial causes
  • Antitubercular therapy
  • Immunosuppressants in autoimmune disease
  • Dialysis (in the case of uremia)
• Restricted physical activity in acute pericarditis ^[4][22]
  • Nonathletes: until symptoms have resolved and CRP has normalized
  • Athletes: until symptoms have resolved, CRP has normalized, and ECG and echocardiogram findings have normalized
• Treatment of concurrent heart failure ^[4][23]
  • Diuretics, e.g., furosemide
  • Sodium restriction < 2 g/day
  • Treatment of concurrent atrial fibrillation with digoxin

Beta blockers and calcium channel blockers should be avoided in constrictive pericarditis, as they may worsen heart failure by slowing a compensatory tachycardia!

Surgical therapy

• Pericardiocentesis: indicated for cardiac tamponade, large pericardial effusion, acute management of effusive-constrictive pericarditis ^[4]
• Pericardiectomy: complete removal of the pericardium ^[4][18][24]
  • Indications: constrictive or effusive-constrictive pericarditis with persistent symptoms of heart failure (NYHA class III or IV)
  • Contraindications
    • Mild disease
    • Very advanced/end-stage constrictive pericarditis
    • Radiation-induced constrictive pericarditis
  • Risks: mortality rate 6–12% ^[4]

Admission criteria ^{[10][6][4][25]}

• Acute pericarditis
  • Most well patients with no indicators of poor prognosis can be managed on an outpatient basis.
  • Consider inpatient admission for the following:
    • Indicators of poor prognosis in acute pericarditis are present. ^[4]
      • Fever > 38^oC
      • Subacute onset
      • Large pericardial effusion
      • Immunosuppression
      • Anticoagulant therapy
      • Elevated troponin
      • Recurrent pericarditis
      • Signs of hemodynamic compromise (e.g., hypotension, jugular venous distention)
      • No response to NSAIDs after one week
    • Suspicion of specific etiologies (e.g., tuberculosis, malignancy, or bacterial infection)
• Chronic pericarditis: Consider admission in patients who have symptoms of congestive heart failure, or in whom further diagnostic evaluation is necessary.

• Constrictive pericarditis
• Cardiac tamponade

We list the most important complications. The selection is not exhaustive.