Pericardial Effusion - Etiology

Etiology

The cause of abnormal fluid production depends on the underlying etiology, but it is usually secondary to injury or insult to the pericardium (ie, pericarditis). Transudative fluids result from obstruction of fluid drainage, which occurs through lymphatic channels. Exudative fluids occur secondary to inflammatory, infectious, malignant, or autoimmune processes within the pericardium.

In up to 60% of cases, pericardial effusion is related to a known or suspected underlying process. Therefore, the diagnostic approach should give strong consideration to coexisting medical conditions.

Idiopathic

In many cases, the underlying cause is not identified. However, this often relates to the lack of extensive diagnostic evaluation.

Infectious

Human immunodeficiency virus (HIV) infection can lead to pericardial effusion through several mechanisms, including the following:

Secondary bacterial infection

Opportunistic infection

Malignancy (Kaposi sarcoma, lymphoma)

"Capillary leak" syndrome, which is associated with effusions in other body cavities

The most common cause of infectious pericarditis and myocarditis is viral. Common etiologic organisms include coxsackievirus A and B, and hepatitis viruses. Other forms of infectious pericarditis include the following:

Pyogenic - Pneumococci, streptococci, staphylococci, Neisseria, Legionella species

Tuberculous

Fungal - Histoplasmosis, coccidioidomycosis, Candida

Syphilitic

Protozoal

Parasitic

Neoplastic

Neoplastic disease can involve the pericardium through the following mechanisms:

Direct extension from mediastinal structures or the cardiac chamber

Retrograde extension from the lymphatic system

Hematologic seeding

Malignancies with the highest prevalence of pericardial effusion include lung (37% of malignant effusions) and breast (22%) malignancies, as well as leukemia/lymphoma (17%). However, patients with malignant melanoma or mesothelioma also have a high prevalence of associated pericardial effusions.

Postoperative/postprocedural

Pericardial effusions are common after cardiac surgery. In 122 consecutive patients studied serially before and after cardiac surgery, effusions were present in 103 patients; most appeared by postoperative day 2, reached their maximum size by postoperative day 10, and usually resolved without sequelae within the first postoperative month.

In a retrospective survey of more than 4,500 postoperative patients, only 48 were found to have moderate or large effusions by echocardiography; of those, 36 met diagnostic criteria for tamponade. The use of preoperative anticoagulants, valve surgery, and female sex were associated with a higher prevalence of tamponade.

Early chest tube removal following cardiac surgery, around midnight on the day of surgery, may be associated with an increased risk of postoperative pleural and/or pericardial effusions requiring invasive treatment.{ref 88} This may occur even if chest tube output during the last 4 hours is below 150 mL compared with removal of the tubes next morning.

Symptoms and physical findings of significant postoperative pericardial effusions are frequently nonspecific, and echocardiographic detection and echo-guided pericardiocentesis, when necessary, are safe and effective; prolonged catheter drainage reduces the recurrence rate.

Pericardial effusions in cardiac transplant patients are associated with an increased prevalence of acute rejection.

Other

Less common causes of pericardial effusion include the following:

Uremia

Myxedema

Severe pulmonary hypertension

Radiation therapy

Acute myocardial infarction - Including the complication of free wall rupture

Aortic dissection - Leading to hemorrhagic effusion from leakage into the pericardial sac

Trauma

Hyperlipidemia

Chylopericardium

Familial Mediterranean fever

Whipple disease

Hypersensitivity or autoimmune related - Systemic lupus erythematosus, [5] rheumatoid arthritis, ankylosing spondylitis, rheumatic fever, scleroderma, Wegener granulomatosis

Drug associated - Eg, procainamide, hydralazine, isoniazid, minoxidil, phenytoin, anticoagulants, methysergide