The American College of Gastroenterology has identified a number of risk factors of GI toxicity related to NSAID use: age >60 years, history of a previous adverse event, high dose NSAIDs, concurrent use of glucocorticoids, or use of concurrent anticoagulants.42Hence, a number of the authors of various trials including a NSAID treatment arm have recommend GI protection with 20 mg/day of omeprazole.33The length of treatment is debatable. the electrocardiographic features seen in pericarditis are also evident in acute myocardial infarction, whereas treatment of the two conditions differs substantially, making the differential diagnosis of paramount importance. The pericardium is a double-layered fibroserous sac that covers the entire myocardium and extends onto the great vessels. Each layer is approximately 12 mm thick. The space between these layers contains approximately 1535 mL of serous fluid known as pericardial fluid.2Pericarditis is due to an inflammatory process affecting the inner visceral layer and the outer parietal layer HIRS-1 of the pericardium. Left undiagnosed and untreated, chronic inflammation of the pericardium can result in complications such as pericardial wall thickening and calcification leading to a constrictive pericarditis (Table 1). Acute pericarditis can lead to fluid accumulation within the pericardial space known as pericardial effusion. In 15% of patients with pericarditis, rapid accumulation of fluid into the pericardial space can result in hemodynamic compromise due to impaired filling of intracardiac chambers during diastole and lead to cardiac tamponade with hemodynamic compromise, which is a life-threatening condition if not recognized and treated promptly.3 == Table 1. == Pericarditis classification scheme3,4 Copyright 2010, Wolters Kluwer Health. Adapted with permission from Imazio M, Spodick DH, Brucato A, Trinchero R, Adler Y. Controversial issues in the management of pericardial diseases.Circulation. 2010;121(7):916928. == Etiology == The etiology of acute pericarditis is at times difficult to IOWH032 identify. As many as 85% of acute pericarditis cases are of unknown etiology, labeled as idiopathic origin.4,5In immunocompetent patients where symptoms may resolve in a matter of days, 90% of the time the etiology is thought to be viral or idiopathic, and no further workup is needed.6 The cause of inflammation in viral illness is due to the replication of the virus in the pericardium which elicits a cellular response, which in turn leads to inflammation. Even without viral replication, there are a number of viral genomic fragments that can also elicit an inflammatory response. Moreover, antibodies to these fragments can be found in the myopericardium for years and may be an etiology of recurrent pericarditis.7These cases are often preceded by a recent flu-like illness or gastrointestinal symptoms and more often are secondary to coxsackie B viruses or echoviruses. However, if tamponade or effusion is present on examination without signs of inflammation (pain, friction rub) the practitioner must consider tuberculosis (TB) or neoplasia in the differential diagnosis.8In Westernized nations, bacterial pericarditis is not common, but it is still often seen in the developing world, and if untreated is 100% fatal. Even with treatment, mortality IOWH032 still approaches 40% due to complications such as tamponade, bacterial toxicity/sepsis, or other infectious complications.9As the incidence of human immunodeficiency virus (HIV) increases, the IOWH032 incidence of purulent pericarditis will likely also increase. In fact, pericarditis is the most common cardiovascular manifestation of acquired immunodeficiency syndrome (AIDS), occurring in up to 20% of patients with HIV/AIDS.10TB pericarditis is also possible, especially in the immunocompromised patient. The classic presentation is a subacute illness with fever, effusion, and or tamponade. The mortality with TB pericarditis is as high as 85%. In developed countries, the incidence is low, but in sub-Saharan Africa, the incidence of TB pericarditis reaches approximately 70%.11 Neoplasms may also be associated with pericarditis. While primary tumors are extremely rare, mesothelioma is the most common primary cancerous process. Metastatic tumors are 40 times more likely, with the common primary lesions being lung, breast, melanoma, lymphoma, and/or leukemia.12 Dresslers syndrome is a postmyocardial infarction (MI) finding that develops in weeks to months post-MI or cardiac surgery. It is thought to IOWH032 be due to an autoimmune reaction mediated by antibodies due to various myocardial antigens.1 Renal failure may also cause large pericardial effusions in up to 20% of patients. Two basic forms of pericarditis.