Pericardial syndrome includes pericardites acute pericardial effusion and cardiac tamponade, recurrent pericarditis squeezing chronic pericarditis. The etiologies are very numerous and can be classified as infectious, neoplastic, metabolic or systemic, toxic causes. Diagnosis is difficult, and 80% of etiologies remain classified idiopathic. In their laboratory to improve the diagnosis of this syndrome investigators have developed a strategy of systematic prescription of biological tests by kit. This prescription by 'kit' strategy proved its interest by comparison with an intuitive requirement of biological. In this study investigators want to improve the diagnostic causative of pericarditis by implementing a new diagnostic strategy. This new strategy includes (i) samples additional less invasive for the patient, the swab pharyngeal and nasal, (ii) the addition of at the outset of more effective diagnostic techniques: specific Polymerase Chain Reaction (PCR)