What Is Pericarditis?

Pericarditis is the inflammation of the pericardium, the thin, sac-like membrane that surrounds and protects the heart. When this lining becomes inflamed, it can cause sharp chest pain, breathing difficulty, and other symptoms that mimic heart attacks. While it’s often short-lived, untreated or recurring pericarditis can lead to serious complications such as pericardial effusion or cardiac tamponade.

Understanding the causes of pericarditis is crucial for early diagnosis and proper management. It is not a disease in itself, but a response to various underlying triggers.

Viral Infections

Viral infections are the most common cause of pericarditis, particularly in developed countries. These infections can inflame the pericardium directly or stimulate the immune system to attack the heart lining.

Common viral culprits include:

  • Coxsackievirus (especially group B)

  • Echovirus

  • Influenza

  • HIV

  • Hepatitis B and C

  • COVID-19 (SARS-CoV-2)

Most viral pericarditis cases are self-limited, but some can progress to chronic inflammation, especially if not promptly managed.

Bacterial Infections

Bacterial pericarditis is less common but more serious than viral types. It often occurs due to the spread of infection from nearby tissues or through the bloodstream.

Bacteria known to cause pericarditis include:

  • Streptococcus and Staphylococcus species

  • Tuberculosis (Mycobacterium tuberculosis)

  • Pneumococcus

  • Lyme disease (Borrelia burgdorferi)

Tuberculous pericarditis is particularly dangerous and prevalent in regions with high TB rates. It requires aggressive treatment and sometimes surgical intervention.

Fungal and Parasitic Infections

Fungal and parasitic infections are rare causes of pericarditis but can occur in immunocompromised individuals, such as those with cancer, HIV/AIDS, or organ transplants.

Fungi associated with pericarditis include:

  • Histoplasma capsulatum

  • Aspergillus

  • Candida

Parasitic infections, such as Chagas disease (Trypanosoma cruzi), can also inflame the pericardium, usually as part of systemic illness.

Autoimmune Diseases

Autoimmune or inflammatory diseases can trigger the body’s immune system to mistakenly attack the pericardium.

Common autoimmune conditions linked to pericarditis:

  • Systemic lupus erythematosus (SLE)

  • Rheumatoid arthritis

  • Scleroderma

  • Ankylosing spondylitis

  • Inflammatory bowel disease (IBD)

In these cases, pericarditis may be recurrent and require long-term anti-inflammatory or immunosuppressive therapy.

Post-Heart Attack (Dressler’s Syndrome)

Some patients develop pericarditis days to weeks after a heart attack, a condition known as post-myocardial infarction pericarditis or Dressler’s syndrome.

It’s thought to be an autoimmune response triggered by heart muscle injury. Symptoms can include:

  • Recurrent chest pain

  • Low-grade fever

  • Pericardial friction rub

  • Elevated inflammatory markers

Dressler’s syndrome often responds well to NSAIDs or corticosteroids.

Post-Surgical or Trauma-Related

Pericarditis can also occur after any form of chest trauma or cardiac surgery. This includes:

  • Coronary artery bypass graft (CABG)

  • Valve repair or replacement

  • Open-heart procedures

  • Penetrating or blunt chest injury

This form of pericarditis may be part of post-pericardiotomy syndrome and often has a delayed onset after the event.

Cancer and Tumors

Cancer-related pericarditis can result from direct invasion of the pericardium by a tumor or from cancer treatments. Common cancers associated with pericardial involvement include:

  • Lung cancer

  • Breast cancer

  • Lymphoma and leukemia

  • Mesothelioma (primary pericardial tumor)

Radiation therapy and chemotherapy can also damage the pericardium, especially in patients receiving high doses or chest-directed treatments.

Kidney Failure (Uremic Pericarditis)

In people with advanced kidney disease, waste products can build up in the bloodstream, leading to uremic pericarditis.

Key features include:

  • Chest pain not always relieved by sitting forward

  • No evidence of infection

  • Occurs in patients with end-stage renal disease (ESRD)

Dialysis typically improves symptoms, but in severe cases, pericardial fluid drainage may be required.

Medications and Drug Reactions

Certain medications are known to cause pericarditis as a rare side effect. These drug-induced cases are believed to be immune-mediated.

Medications that may trigger pericarditis include:

  • Hydralazine (for blood pressure)

  • Isoniazid (for tuberculosis)

  • Procainamide (antiarrhythmic)

  • Chemotherapy agents (e.g., doxorubicin)

  • Phenytoin (anti-seizure)

Diagnosis often involves ruling out other causes and stopping the offending medication.

Radiation Exposure

Radiation therapy directed at the chest can damage the pericardial tissue. This damage may occur immediately or years later and lead to:

  • Acute pericarditis

  • Chronic pericardial thickening

  • Constrictive pericarditis

Radiation-induced pericarditis is particularly common in patients treated for Hodgkin lymphoma or breast cancer.

Systemic Inflammatory Syndromes

Some systemic inflammatory conditions that are not strictly autoimmune can cause pericarditis. These include:

  • Sarcoidosis

  • Adult-onset Still’s disease

  • Familial Mediterranean fever

These diseases involve multi-system inflammation and often require immunosuppressants to control pericardial involvement.

Idiopathic Causes

In a large number of cases, no clear cause is identified despite thorough investigation. These are termed idiopathic pericarditis. Experts believe many of these are likely viral in origin, even if a specific virus is not detected.

Idiopathic pericarditis typically:

  • Responds well to NSAIDs

  • Has a low recurrence rate if treated early

  • Is diagnosed through exclusion of all other causes

Nevertheless, close follow-up is important, especially if symptoms recur.

Pericarditis and COVID-19

Since the emergence of COVID-19, there have been increasing reports of viral pericarditis linked to SARS-CoV-2. It can occur during the acute infection or as part of post-COVID syndrome (long COVID).

Symptoms include:

  • Sharp chest pain

  • Shortness of breath

  • Fever or fatigue

COVID-related pericarditis may respond to standard anti-inflammatory treatment, but some cases are more resistant and require steroids or colchicine.

Lifestyle-Related Triggers

Though not direct causes, certain lifestyle factors can contribute to pericarditis onset or recurrence:

  • Smoking and alcohol abuse weaken immunity

  • Stress can exacerbate autoimmune conditions

  • Poor hydration and nutrition may impair recovery

  • Excessive physical activity during recovery can worsen symptoms

Managing these factors can support treatment and prevent relapses.

Risk Factors to Watch

People at higher risk of developing pericarditis include those who:

  • Recently had a viral infection

  • Have an autoimmune condition

  • Underwent heart surgery or suffered chest trauma

  • Are receiving radiation or chemotherapy

  • Have advanced kidney disease

Recognizing these risk groups helps with early diagnosis and intervention.

Complications from Delayed Treatment

If pericarditis is left untreated, it can lead to complications like:

  • Pericardial effusion: Fluid buildup around the heart

  • Cardiac tamponade: Life-threatening compression of the heart

  • Constrictive pericarditis: Chronic scarring and loss of pericardial flexibility

These complications often require hospitalization or surgery and are more likely if the underlying cause goes unaddressed.

Prevention and Early Action

While not all forms of pericarditis are preventable, early detection and treatment can reduce the risk of complications. Strategies include:

  • Managing infections quickly and completely

  • Treating autoimmune conditions aggressively

  • Being cautious with high-risk medications

  • Monitoring for symptoms after heart surgery or trauma

Preventive measures can also include vaccines (like flu or hepatitis) and regular check-ups for high-risk individuals.

Conclusion

Pericarditis has many potential causes, ranging from viral infections and autoimmune diseases to cancer and kidney failure. In some cases, the cause may remain unknown, but understanding the range of possible triggers can guide better diagnosis and treatment.

Whether pericarditis is acute, chronic, or recurrent, addressing the underlying cause is key to managing symptoms and preventing serious complications. If you experience chest pain that gets worse when lying down or breathing deeply, don’t ignore it—seek medical evaluation promptly.