Potential Causes of Pericarditis

Woman Holding Her Chest

One of the types of heart inflammation the Myocarditis Foundation researches is called pericarditis. Very often, the best way to treat pericarditis is to address the condition that caused it – but first, you need to find out what that is. “Pericarditis has a variety of causes, some more common than others,” says Dr. Allan Klein, MD, Director of the Center for the Diagnosis and Treatment of Pericardial Diseases at Cleveland Clinic. “Understanding the causes is essential to treating the underlying condition.”

An Overview of Pericarditis

Before exploring the causes, it helps to begin with an understanding of what pericarditis is. In short, pericarditis is inflammation of the pericardium, the thin protective membrane that surrounds and supports the heart. It often causes chest pain, shortness of breath, abnormal heart rhythms, and other potential symptoms as well. There are also several subtypes, including:

  • Acute pericarditis: This form begins suddenly but typically does not have a long duration (less than 3 months). It can lead to recurrent pericarditis (improves after 4-6 weeks but then recurs) or incessant (lasts more than 4-6 weeks).
  • Chronic pericarditis: This form can last for more than three months.
  • Constrictive pericarditis: This form occurs when the pericarditis causes scar tissue and calcification. The bands of stiff, hard tissue compress the heart and prevent it from filling properly and cause heart failure.

Most cases are mild and can improve on their own, but more severe cases may require anti-inflammatory medication or even pericardiectomy. Early diagnosis is key to preventing long-term complications.

The Most Common Causes

According to Klein, the majority of pericarditis is caused by a viral illness.  He estimates that about 80% of cases begin this way. The virus itself can be something as simple as a common cold or flu. If the virus gets into the bloodstream, it can travel to the heart and infect the pericardial tissue, causing inflammation and swelling.

Klein also estimates that another 5 percent of pericarditis cases occur after a cardiac injury. “For example,” he says, “if you have open-heart surgery where the doctors have to open the pericardium, that surgical trauma can cause pericardial inflammation ( post-pericardiotomy syndrome).” The injury might also be the result after a heart attack or other trauma such as an EP procedure (atrial fibrillation ablation, or pacemaker insertion).

Though viral infections and heart injuries are the most common causes of pericarditis, they’re not the only possible sources. Autoimmune disorders like lupus, AIDS, tuberculosis, or rheumatoid arthritis are responsible for their fair share of cases. Other causes including cancer or hypothyroidism might be responsible for the inflammation.

Who Is at Risk?

Though they aren’t causes of pericarditis by themselves, there are a few risk factors that can increase a person’s chance of getting it. One major factor is steroid use. “If you introduce prednisone (Medrol dose pack) then take them away too quickly, the withdrawal can increase your risk,” says Klein. Blood thinners can also cause bleeding inside the pericardium, resulting in hemorrhagic pericarditis.

Another at risk for recurrent pericarditis includes those that are undertreated the first time. “A lot of pericarditis we see will get better with time and medications such as NDAIDs, colchicine and sometimes prednisone,” explains Klein, “but sometimes it can evolve into a more complicated condition.” Those cases may need new biologic medications such as interleukin-1 blockers including anakinra or rilonacept

Learn More about Pericarditis

By understanding the causes of pericarditis, doctors can provide more effective and longer-lasting treatments. At the Myocarditis Foundation, we are dedicated to researching pericarditis to increase our understanding of this disease and how cardiologists can treat it. Contact us to learn more.