Causes of Pericarditis

Pericarditis is a condition marked by inflammation of the Pericarditis, the thin, double-layered sac surrounding the heart. This inflammation can lead to sharp chest pain, a hallmark symptom that often mimics a heart attack. While pericarditis can be acute (short-term) or chronic (lasting more than three months), understanding its causes is essential for early diagnosis and effective treatment.

What Triggers Pericarditis?

The causes of pericarditis are wide-ranging, including infections, autoimmune conditions, injury, and even certain medical treatments. In some cases, the exact cause remains unknown, termed as idiopathic pericarditis. However, in many patients, identifiable triggers can be determined through thorough medical evaluation.

1. Viral Infections :- The Most Common Cause Viral infections are the leading causes of pericarditis. These infections often resolve on their own but can trigger inflammation in the pericardium due to the body’s immune response.Common viruses associated with pericarditis include:
   • Coxsackievirus (especially B type)
   • Echovirus
   • Influenza virus
   • Adenovirus
   • HIV
   • Hepatitis B and C

   These viruses may initially affect the respiratory or gastrointestinal tract and later spread to the pericardial tissue. In some cases, patients might not even recall a recent viral illness.

2. Bacterial Infections :- Though less common, bacterial pericarditis is usually more severe and requires immediate medical attention. Bacteria can invade the pericardium directly or spread from other parts of the body via the bloodstream.Common bacterial sources include:
   • Tuberculosis (especially in developing countries)
   • Pneumococcal or staphylococcal infections
   • Lyme disease (from Borrelia burgdorferi)
   • Fungal infections (Candida or Histoplasma in immunocompromised individuals)

   Tuberculous pericarditis is a chronic form, often found in regions where tuberculosis is endemic. It tends to cause thickening of the pericardium, leading to a condition called constrictive pericarditis

3. Autoimmune and Inflammatory Disorders :- The body’s own immune system can mistakenly attack the pericardial tissues, resulting in inflammation. Autoimmune pericarditis can occur as a primary condition or in association with systemic diseases.Key autoimmune-related causes:
   • Systemic lupus erythematosus (SLE)
   • Rheumatoid arthritis
   • Scleroderma
   • Mixed connective tissue disease
   • Sarcoidosis
   • Inflammatory bowel disease (Crohn’s disease and ulcerative colitis)

   In such conditions, pericarditis may recur and require long-term immunosuppressive therapy.

4. Post-Heart Injury Syndromes (Dressler’s Syndrome) :- Injury to the heart or pericardium, whether from surgery or trauma, can cause the immune system to mount a delayed response, resulting in pericarditis. This condition, known as post-pericardiotomy syndrome or Dressler’s syndrome, typically arises days to weeks after:
   • Heart surgery (e.g., coronary artery bypass grafting)
   • Myocardial infarction (heart attack)
   • Chest trauma
   • Invasive cardiac procedures like pacemaker insertion

   These syndromes are considered autoimmune in nature and may involve fever, chest pain, and fluid accumulation in the pericardial space.

5. Cancer-Related Pericarditis :- Certain cancers can invade or press against the pericardium, leading to inflammation or fluid accumulation (malignant pericardial effusion). This is more common in advanced-stage cancers.Common malignancies associated with pericarditis:
   • Lung cancer
   • Breast cancer
   • Lymphomas (Hodgkin and Non-Hodgkin)
   • Leukemia
     Mesothelioma

   Sometimes, cancer treatments like radiation therapy or chemotherapy (e.g., doxorubicin) may also induce pericarditis.

6. Kidney Failure (Uremic Pericarditis) :- In patients with chronic kidney disease or end-stage renal failure, toxic waste products (uremia) build up in the bloodstream. These substances can irritate the pericardium, leading to uremic pericarditis, particularly in those not receiving adequate dialysis.
7. Hypothyroidism :- Severe, untreated hypothyroidism can lead to fluid buildup around the heart, known as pericardial effusion. Though not always inflammatory, it can progress to pericarditis in some patients.
8. Medications and Drug-Induced Pericarditis :- Certain medications are known to cause pericarditis as a side effect, either through allergic reactions or by promoting inflammation.Notable drugs include:
   • Hydralazine (used for hypertension)
   • Isoniazid (anti-tuberculosis drug)
   • Procainamide (used in arrhythmias)
   • Phenytoin (anti-seizure)
   • Chemotherapeutic agents (cyclophosphamide, methotrexate)

   In most cases, stopping the offending medication resolves the condition.

9. Radiation Therapy :- Patients who undergo radiation therapy to the chest for cancers like lymphoma or breast cancer are at risk of radiation-induced pericarditis, especially when high doses are used. The condition may present months or even years after treatment and can lead to chronic fibrosis of the pericardium.
10. Other Rare Causes :- A few other rare but noteworthy causes include:
    • Aortic dissection :- Can rupture into the pericardial space causing inflammation.
    • Myxedema :- Associated with extreme hypothyroidism.
    • Pericardial cysts :- Benign growths that may irritate the pericardial lining.
    • Genetic syndromes :- Like Familial Mediterranean Fever, can include recurrent pericarditis as a symptom.

Conclusion

Pericarditis is a multifactorial condition with a wide range of potential causes from common viral infections to complex autoimmune disorders and cancer-related complications. Identifying the underlying cause is crucial, as it directly impacts the treatment approach and prognosis. While many cases are mild and self-limiting, others may require intensive medical or surgical management.

Timely diagnosis, guided by a patient’s medical history, symptoms, and diagnostic tests, can prevent complications like pericardial effusion, cardiac tamponade, or constrictive pericarditis. If you or a loved one experiences persistent chest pain, especially following a viral illness, cardiac event, or medical treatment, consult a healthcare provider to rule out pericarditis and begin appropriate care.