Pericarditis
Pericarditis is inflammation of the pericardium, the thin sac that surrounds the heart. It can develop suddenly (acute pericarditis), persist or recur over time, or progress to chronic forms with thickening or scarring of the pericardium. Pericarditis is often caused by viral infections but can also result from autoimmune conditions, prior heart attack, cancer, kidney failure, certain medications, or after cardiac procedures. The classic symptom is sharp chest pain that worsens with breathing or lying flat. Imaging—particularly echocardiography and cardiac MRI—plays a central role in diagnosis and monitoring.
What is it?
The pericardium is a thin, two-layered sac that surrounds the heart and the roots of the great vessels. It contains a small amount of fluid that allows the heart to move smoothly within the chest as it beats. Pericarditis is inflammation of this sac, which can cause friction between its layers, pain, and—in some cases—accumulation of fluid (pericardial effusion) or scarring (constrictive pericarditis).
Pericarditis can be classified by how it develops and how long it lasts. Acute pericarditis begins suddenly and typically lasts up to a few weeks. Incessant pericarditis lasts more than 4 to 6 weeks but less than 3 months. Recurrent pericarditis involves new episodes after periods of being symptom-free, and chronic pericarditis lasts longer than 3 months. In some cases, ongoing inflammation eventually leads to thickening and scarring of the pericardium, producing constrictive pericarditis—a more advanced and serious form.
There are many possible causes. Viral infections are the most common identified cause in many regions and include a wide range of common viruses. Bacterial, fungal, and tuberculous causes are less common but important, particularly in immunocompromised patients or in regions where tuberculosis is more prevalent. Autoimmune and inflammatory conditions (such as lupus, rheumatoid arthritis, vasculitis, and inflammatory bowel disease) can produce pericarditis. Pericarditis can also follow a heart attack (early or late post-myocardial infarction pericarditis, including Dressler syndrome), develop after heart surgery or cardiac procedures, occur with kidney failure (uremic pericarditis), and complicate certain cancers (either through direct involvement or as a paraneoplastic process). Some medications, prior chest radiation, and metabolic conditions are also recognized causes. In many cases, despite testing, no specific underlying cause is identified (“idiopathic”), and viral infection is presumed.
The classic symptom of pericarditis is sharp, often stabbing chest pain that may radiate to the shoulder or neck. The pain typically worsens with deep breathing, coughing, swallowing, or lying flat, and improves with sitting up and leaning forward. Other possible symptoms include low-grade fever, fatigue, malaise, palpitations, shortness of breath, and symptoms of an underlying illness (such as recent viral infection or symptoms of autoimmune disease). Significant pericardial effusion can cause more pronounced shortness of breath, and severe accumulation may lead to cardiac tamponade—a life-threatening condition in which pressure on the heart prevents adequate filling. Constrictive pericarditis can produce signs of right-sided heart failure, including leg swelling, abdominal swelling, and exercise intolerance.
Diagnosis combines clinical assessment, ECG, blood tests, and imaging. ECG often shows characteristic widespread changes (such as diffuse ST elevation and PR depression) that help distinguish pericarditis from heart attack. Blood tests typically show elevated markers of inflammation (such as CRP and ESR), and troponin may be elevated when there is concurrent inflammation of the heart muscle (myopericarditis). Echocardiography evaluates for pericardial effusion, tamponade physiology, and overall heart function. Cardiac MRI is particularly valuable because it can detect pericardial inflammation and edema, demonstrate thickening or scarring, and help characterize the cause and complications. Chest X-ray and CT add additional information. Testing for specific underlying causes—including viral, autoimmune, infectious, and metabolic studies—is guided by the clinical picture.
Important to Know
Management of pericarditis depends on the cause, severity, presence of complications, and overall clinical picture. Most cases of acute idiopathic or viral pericarditis are managed in the outpatient setting and respond well to anti-inflammatory therapy. The typical first-line treatment is a combination of nonsteroidal anti-inflammatory drugs (NSAIDs—such as ibuprofen or aspirin) and colchicine. Colchicine has been shown in randomized trials to reduce the risk of recurrent pericarditis and is now considered an essential part of treatment for most patients without contraindications.
Treatment courses for NSAIDs are typically several weeks, and colchicine is generally continued for several months, with tapering based on symptoms and inflammatory markers. Corticosteroids are usually avoided when possible in idiopathic and viral pericarditis because they are associated with higher rates of recurrence; however, they may be used when NSAIDs and colchicine are contraindicated, ineffective, or when specific causes (such as certain autoimmune conditions) require them. Newer biologic agents, such as IL-1 blockers, have become important options for recurrent or refractory pericarditis in selected patients.
Activity restriction is generally recommended during the acute phase of pericarditis, with gradual return to exercise as inflammation resolves and inflammatory markers normalize. Athletes and very active individuals may require longer activity restriction.
When a specific underlying cause is identified, treatment is directed at that condition—antibiotics for bacterial pericarditis, antimicrobial treatment for tuberculous pericarditis, treatment of autoimmune disease, dialysis for uremic pericarditis, and oncologic care for cancer-related pericarditis.
Significant complications require specific management. Large pericardial effusions, cardiac tamponade, or purulent pericarditis often require pericardiocentesis (drainage of the fluid) or, in selected cases, surgical drainage. Constrictive pericarditis may require pericardiectomy, a surgical procedure to remove the thickened pericardium, in patients with significant symptoms.
Care is typically coordinated by primary care clinicians, cardiologists (sometimes including subspecialists in pericardial disease for complex or recurrent cases), rheumatologists, infectious disease specialists, and other relevant specialists. Imaging findings are interpreted alongside symptoms, examination, and other test results.
Most patients with acute pericarditis recover well, although some develop recurrences. Long-term outcomes are generally favorable when patients are appropriately treated and adherent to therapy.
Red flag symptoms include severe or worsening shortness of breath, low blood pressure, fainting, severe chest pain that does not improve with usual measures, signs of cardiac tamponade (including significant breathing difficulty and weak pulse), high fever with severe symptoms, or signs of shock. These warrant urgent medical evaluation, as they may indicate complications such as tamponade or another serious condition.