Echocardiography in Congenital and Acquired

O CONGENITAL ABSENCE of the pericardium is a well described but uncommon condition.'`9 In 1959, Ellis et al.2 noted that in the vast majority of cases partial or complete left-sided pericardial defects were present; right-sided or total pericardial absence is extremely rare. Although characteristic roentgenographic findings are usually present in congenital absence of the pericardium, clinically it may be mistaken for a variety of cardiac and noncardiac conditions. These include atrial septal defect, idiopathic dilatation of pulmonary artery, pulmonic stenosis, cardiac tumor, mitral valve disease, left ventricular aneurysm, corrected transposition of the great vessels, left hilar adenopathy, mediastinal tumor and bronchogenic carcinoma.7' I Associated abnormalities of the heart and lungs may also occur.2' I The diagnosis can be definitively established by inducing a left pneumothorax; air appears abnormally under the right pericardium when the patient is turned to the left lateral decubitus position.4 The purpose of this study was to evaluate the echocardiographic appearance of pericardial absence in order to determine whether the ultrasound technique could be used reliably to differentiate this condition from those which it clinically resembles, especially atrial septal defect. Two groups of patients were included: 1) patients with congenital absence of the pericardium and 2) patients with acquired absence of the pericardium.