The most typical form of relapsing pericarditis (table 1) occurs after a first episode of idiopathic benign pericarditis, presumably of viral origin. The viruses most frequently implicated are enterovirus, mainly coxsackie B. Higher concentrations of immunoglobulin IgM antibodies have been found in patients with relapses, which can express a persistent viral antigenic stimulation due to persistent viral infection or new exposure to viral illness. Autoimmune responses can certainly play a role in the pathogenesis of recurrent idiopathic or postviral pericarditis.1
Inadequate anti-inflammatory treatment of the index attack can explain the relapses in some cases. However, there are no controlled clinical trials about the optimal duration of treatment and the appropriate doses of the drugs. French authors8,9
have suggested that corticosteroid treatment given in the index attack can favour the occurrence of relapses because of their deleterious effect of viral replication. In the series of Raatikka and colleagues10
the mean number of relapses in steroid treated patients was much higher than those not so treated (8.3 v
4.5), during a follow up period of four years. Relapsing pericarditis can also occur in the post-myocardial and post-pericardial injury syndromes; relapses after open heart surgery seem to be more frequent in children and adolescents, especially after atrial septal defect closure.10
An immunopathologic mechanism is probably the cause of these relapses as anti-heart antibodies have been found in some cases. Genetic factors may play a role in the development of a relapse as well.10,11
Unlike idiopathic recurrent pericarditis, these cases may eventually evolve to constrictive pericarditis (this especially occurs in those patients who suffer a tamponade caused by haemopericardium in the index attack).1
An immunopathologic mechanism seems to be evident in the relapsing pericarditis of vasculitis–connective tissue disease, especially disseminated lupus erythematosus. Infectious pericarditis caused by specific agents, such as bacterial and tuberculous pericarditis, usually have a subacute or a protracted chronic course with unremitting symptoms, even on common anti-inflammatory drugs, but do not present with a true picture of relapsing pericarditis with intervals of symptom-free periods.12
Neoplastic pericarditis can show an oscillating clinical course, and, occasionally, apparently self limited pericarditis with subsequent reappearance of pericardial manifestations.13
However, patients with pericardial malignancies, either primary or metastatic, usually have a very poor prognosis, with no propensity for reoccurrence or chronicity to become manifest.
Table 1 Possible causes of relapsing pericarditis
In summary, the most frequent causes of relapsing pericarditis are idiopathic or viral pericarditis and post-pericardial injury syndromes. In patients without previous cardiac surgery, and in whom connective tissue disease has been ruled out, relapsing–intermittent pericarditis with symptom-free periods longer than six weeks makes the diagnosis of idiopathic/viral pericarditis practically certain. The pathogenesis of the syndrome can be related to persistent or recurrent viral infection, an immunopathologic mechanism, or an inadequate drug treatment regimen. It has been suggested that the administration of corticosteroids during the target episode can propitiate the appearance of recurrences.