Pericardial Effusion and Tamponade.

Pericardial effusion may occur as a result of a variety of clinical conditions, including viral, bacterial, or fungal infections and inflammatory, postinflammatory, autoreactive, and neoplastic processes. More common causes of pericardial effusion and tamponade include malignancy, renal failure, viral and bacterial infectious processes, radiation, aortic dissection, and hypothyroidism. It can also occur after trauma or acute myocardial infarction (as in postpericardiotomy syndrome following cardiac or thoracic surgery) or as an idiopathic pericardial effusion. Although pericardial effusion is common in patients with connective tissue disease, cardiac tamponade is rare. Among medical patients, malignant disease is the most common cause of pericardial effusion with tamponade. Table 1 shows the causes of pericardial tamponade. The effusion fluid may be serous, suppurative, hemorrhagic, or serosanguineous. The pericardial fluid can be a transudate (typically occurring in patients with congestive heart failure) or an exudate. The latter type, which contains a high concentration of proteins and fibrin, can occur with any type of pericarditis, severe infections, or malignancy. Once the diagnosis of pericardial effusion has been made, it is important to determine whether the effusion is creating significant hemodynamic compromise. Asymptomatic patients without hemodynamic compromise, even with large pericardial effusions, do not need to be treated with pericardiocentesis unless there is a need for fluid analysis for diagnostic purposes (eg, in acute bacterial pericarditis, tuberculosis, and neoplasias). The diagnosis of pericardial effusion/tamponade relies on a strong clinical suspicion and is confirmed by echocardiography or other pericardial imaging modalities. Alternatively, when the diagnosis of cardiac tamponade is made, there is a need for emergency drainage of pericardial fluid by pericardiocentesis or surgery to relieve the hemodynamic compromise. Following pericardiocentesis, it is necessary to prevent recurrence of tamponade. Intrapericardial injection of sclerosing agents, surgical pericardiotomy, and percutaneous balloon pericardial window creation are techniques used to prevent reaccumulation of pericardial fluid and recurrence of cardiac tamponade.