Pericarditis

Pericarditis is inflammation of the pericardium and may be acute or chronic. Acute pericarditis is most commonly caused by a viral infection; however, a number of conditions can cause an inflammatory response in the pericardium. Acute pericarditis typically manifests with low-grade 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 3 months, it is described as chronic pericarditis. Chronic pericarditis is typically either 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
• Relapsing/recurrent pericarditis: recurrence of symptoms after a symptom-free period of 4–6 weeks
• 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 after an acute myocardial infarction
• Postoperative; (postpericardiotomy syndrome): due to blunt or sharp trauma to the pericardium
• Uremia: e.g., due to acute or chronic renal failure
• Radiation
  • Exudative pericarditis: develops acutely during or after radiation therapy ^[6]
  • Constrictive pericarditis: develops several years after radiation therapy ^[7]
• Neoplasms (e.g., Hodgkin lymphoma)
• Autoimmune connective tissue diseases (e.g., rheumatoid arthritis, systemic lupus, scleroderma)
• Trauma

Acute pericarditis ^[8]

• 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 ^[9]
  • Best heard over the left sternal border during expiration while the patient is sitting up and leaning forward ^[10]
  • Occurs in atrial and ventricular systole, as well as early diastole ^[11]
  • Present in 85% of patients with acute pericarditis. ^[12]
• Pericardial effusion
  • Faint heart sounds
  • Ewart sign
• Low-grade intermittent fever, tachypnea, dyspnea, nonproductive cough

Acute pericarditis classically presents with sharp, retrosternal chest pain that is exacerbated by deep inspiration and lessened by sitting up or leaning forward. ^[13][14]

Chronic pericarditis

Constrictive pericarditis ^[5][8]

• Symptoms of fluid overload (i.e., backward failure)
  • Jugular vein distention, ↑ jugular venous pressure
  • Prominent x descents and y descents in jugular venous pressure ^[8]
  • 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: decreased blood pressure amplitude by at least 10 mm Hg during deep inspiration ^[12]

The majority of patients with constrictive pericarditis present with symptoms of heart failure (predominantly dyspnea on exertion and edema). ^[15]

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

Purulent pericarditis

• Definition: infection of the pericardium with macroscopic or microscopic evidence of pus in the pericardial space
• Etiology
  • Most commonly a complication of thoracic surgery or cardiac injury
  • Typically caused by Staphylococcus spp., Streptococcus spp., or Mycobacterium tuberculosis
• Clinical features
  • High fever, tachycardia
  • Chest pain
  • Dyspnea, cough
• Diagnosis
  • Physical examination: pericardial friction rub and/or faint heart sounds on auscultation
  • ECG: See “ECG features of pericarditis” below.
  • Echocardiography: pericardial effusion
  • Pathology: gross pus or microscopic evidence of purulence in the pericardial space
• Management
  • Pericardiocentesis to evacuate pericardial effusion; order cultures of pericardial fluid and blood
  • Empiric intravenous antibiotic therapy (e.g., vancomycin, ceftriaxone, or meropenem) that is subsequently adjusted according to antibiogram
  • In case of loculations: surgical drainage and/or intrapericardial fibrinolysis

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).

Rule out other causes of acute chest pain (e.g., myocardial infarction, myocarditis) before making a diagnosis of acute pericarditis. ^[14]

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 features of pericarditis

Not all patients go through all stages and manifestations may vary. In particular, pericarditis due to uremia may not involve characteristic ECG changes. ^[16]

• 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.See also “Differential diagnoses 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 study to evaluate for pericardial disease ^[4][5]
  • Findings: pericardial effusion may be present, often normal
  • See “Subxiphoid view” of the “FAST scan” in “Point-of-care ultrasound” for a technique to screen for pericardial effusions at the bedside.
• Cardiac MRI
  • Indications: Consider if diagnosis is uncertain; preferred imaging modality to assess pericardium. ^[4]
  • Findings
    • Thickened pericardium, pericardial enhancement, pericardial effusion ^[17]
    • May show associated myocarditis ^[17]
• 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

Echocardiography is often normal in patients with pericarditis but is needed to rule out pericardial tamponade and pericardial constriction. ^[14]

Cardiac tamponade can occur with relatively small pericardial effusions if pericardial fluid accumulation is rapid. ^[18]

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

Troponin elevation is not predictive of negative outcomes in pericarditis but does suggest some degree of myocarditis. Significant elevation should raise concern for acute coronary syndrome. ^[19]

Additional diagnostic evaluation

• Pericardiocentesis with pericardial fluid analysis ^[12]
  • Indications: large effusion, tamponade, suspected malignant or purulent pericarditis ^[5]
  • Investigations depend on suspected etiology.
    • Gram stain
    • Bacterial culture
    • Acid-fast bacilli smear microscopy 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 ^[20]
  • LFT: may show elevated transaminases and low albumin ^[21]
• Investigation of the underlying cause: See “Additional diagnostic evaluation” above.

Constrictive pericarditis ^[5][8]

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 ^[22]
  • 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) ^[21]
    • 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 ^[23]
    • 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. ^[24]

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. ^[25]

• Echocardiography, CT, and/or cardiac MRI: pericardial effusion ; pericardial thickening may also be present ^[26][27]
• 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][28]
    • 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). ^[12]

Pharmacotherapy

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

Supportive therapy

• Treat any known underlying causes.
  • Antibiotics for bacterial causes
  • Tuberculosis therapy
  • Immunosuppressants in autoimmune disease
  • Dialysis (in the case of uremia)
• Restrict physical activity in patients with acute pericarditis. ^[4][29]
  • Nonathletes: until symptoms have resolved and CRP has normalized
  • Athletes: until symptoms have resolved, CRP has normalized, and ECG and echocardiogram findings have normalized
• Initiate treatment of heart failure if present. ^[4][30]
  • Diuretics, e.g., furosemide
  • Sodium restriction < 2 g/day
  • Treatment of concurrent atrial fibrillation with digoxin

Special circumstances ^[14]

• Postmyocardial infarction pericarditis: Avoid NSAIDs other than aspirin. ^[31]
• Perimyocarditis: Consider lower doses of NSAIDs , adding a beta blocker , and the avoidance of strenuous physical activity for 6 months. ^[19]
• Constrictive pericarditis with effusion: Use caution when sedating patients or initiating positive pressure ventilation. ^[32]
  • Cardiac output may drop precipitously with even small changes in preload, afterload, or heart rate.
  • Ketamine, midazolam, and etomidate are the preferred anesthetic agents for procedural sedation.

Administration of sedatives and/or the initiation of positive pressure ventilation may precipitate hemodynamic collapse in patients with constrictive pericarditis or effusive-constrictive pericarditis. ^[32][33]

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][25][34]
  • 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]

Disposition ^{[4][8][12][35]}

• 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°C
      • Subacute onset
      • Large pericardial effusion (> 20 mm on echocardiography) ^[14]
      • 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.

• Perform ABCDE assessment.
• Check ECG and TTE.
• Rule out life-threatening differential diagnoses of chest pain.
• Perform immediate pericardiocentesis in unstable patients if there is evidence of tamponade (see “Acute management checklist for cardiac tamponade”)
• Consider advanced imaging if the diagnosis is uncertain.
• Start NSAIDs (if there are no contraindications to NSAIDs).
• Consider colchicine, prednisone, and/or gastroprotective therapy.
  Identify and treat the underlying cause.
• Advise patients to limit strenuous exercise.
• Consider cardiology consult for severe cases.
• Consider indications for admission.
• If the patient is discharged, arrange for a follow-up in 1 week.

• Constrictive pericarditis
• Cardiac tamponade

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