21-year-old male presents complaining of persistent chest pain on
Partial congenital absence of pericardium (left-sided).
There is leftward shift of the cardiac silhouette secondary to the
pericardial defect and a mild pectus deformity. The aorto-pulmonary
window forms an acute angle filled with lung tissue (rather than
pericardium). The pulmonary outflow tract is prominent superiorly.
Lucency at the base of the heart represents interposed lung between
the heart and diaphragm in absence of the pericardium. The
pulmonary vasculature is prominent.
Congenital absence of the pericardium is estimated to occur in 1 in
13,000 persons with a male to female ratio of 3:1. It may be
detected at any age with average age of detection at 21 years. The
entire pericardium or only a portion may be absent. Partial defects
are the most common and occur over the left atrial appendage most
commonly. Diaphragmatic, right atrial and SVC pericardial defects
are less common. Entire absence of the pericardium is rare.
Multiple cardiac and mediastinal abnormalities are associated with
this condition including ASD, PDA, tetralogy of Fallot,
bronchogenic cysts, diaphragmatic hernia, mitral stenosis and
pulmonary sequestration. Partial absence places patients at risk of
herniation through the defect with strangulation of cardiac tissue
(classically the left atrial appendage). Radiologic signs on CXR
include interposed lung between the aorta and pulmonary artery (AP
window), lung between the heart and diaphragm, lung between the
right atrium and right ventricular outflow tract and prominent
pulmonary vasculature if a shunt is present (possible but unproven
in this case). CT may show continuity of the pericardial space with
the pleural cavity. Patients may present with palpitations,
tachycardia, dyspnea, syncope and intermittent chest pain. Chest
pain occurs secondary to torsion of the great vessels and pressure
on the coronary arteries lying at the rim of the defect. EKG
findings may include right axis deviation and right bundle branch
block. If the patient has suffered a pneumothorax, a
pneumopericardium will occur. If symptoms dictate or severe
congenital defects are present, surgical closure of the pericardium
with a pleural flap or resection of the pericardium may be
Miller SM. Cardiac Radiology, The Requisites Series. 1996, Mosby;
St. Louis, MO. Dahnert, Wolfgang, Radiology Review Manual.
Lippincott Williams and Wilkins, Philadelphia, 2000.