intrapericardial

Intrapericardial refers to location within the pericardial sac that surrounds the heart. The term is used to describe anatomical relationships, routes for procedures, and certain pathophysiologic processes occurring inside the pericardial cavity.

Anatomy and context: The pericardium consists of a tough fibrous layer and a serous layer, with a potential space between the parietal and visceral serous layers known as the pericardial cavity. Normally this cavity contains a small amount of lubricating fluid. Intrapericardial is contrasted with intracardiac (inside the heart chambers) and intramyocardial (within the heart muscle).

Clinical significance: Intrapericardial processes include effusions—accumulations of fluid, blood, or other substances within the pericardial cavity. A large or rapidly accumulating intrapericardial effusion can lead to cardiac tamponade, a life-threatening condition in which impaired cardiac filling reduces cardiac output. Common etiologies of intrapericardial effusion or tamponade include malignancy, infection, inflammatory or autoimmune diseases, renal failure, trauma, and iatrogenic causes after cardiac procedures.

Diagnosis and management: Diagnosis is typically by imaging, with echocardiography as the primary tool, supported by computed tomography or magnetic resonance imaging. Signs of tamponade include chamber collapse on imaging and hemodynamic instability. Treatment focuses on removing the fluid and addressing the underlying cause: pericardiocentesis to drain the effusion, with consideration of a pericardial window or pericardiectomy for recurrent cases. In malignant effusions, intrapericardial therapies such as chemotherapy or sclerosants may be used in selected patients to control fluid accumulation.

See also: pericardium, pericardiocentesis, cardiac tamponade, malignant effusion.