Pericardial Effusion or Constriction With Congenital Heart Disease Pericardial compression by effusion or inelastic pericardium in the setting of congenital heart disease is a clinical conundrum Elevated right ventricular pressure, common to many congenital cardiac malformations, prevents diastolic collapse of right-sided chambers despite tamponade The ventricular interdependence and ventricular discordance can exist only if there are two ventricles separated by an intact ventricular septum and is, therefore, absent in patients with a single ventricle and a large ventricular septal defect (Fig 57.11).102,120,121 An atrial septal defect, by nullifying the effect of respiration on ventricular filling, abolishes ventricular interdependence (Fig 57.12A) The hepatic vein when imaged with Doppler, however, continues to demonstrate exaggerated diastolic flow reversal during expiration (see Fig 57.12B) Thickened pericardium shown by CT or MRI may be the only sign of pericardial constriction.71 The diagnosis is particularly difficult in postoperative pericardial constriction when there is no pericardial thickening.122 Conversely, pericardial constriction also modifies the clinical presentation and hemodynamics of congenital heart disease, making the diagnosis perplexing.120–122 FIG 57.11 (A) Transthoracic echocardiogram from a child with ventricular septal defect and pericardial constriction showing absent septal bounce (B) Simultaneous right and left ventricular pressure trace demonstrating absence of ventricular discordance During inspiration, left ventricular systolic pressure falls when right ventricular systolic pressure rises The reverse happens during expiration FIG 57.12 Transthoracic echocardiogram from an adult patient with atrial septal defect and pericardial constriction (A) Absence of respiratory variation in mitral inflow velocity (B) Preserved expiratory exaggeration of diastolic flow reversal in hepatic vein Doppler D, Diastolic forward wave; DR, diastolic reversal; S, systolic forward wave; SR, systolic reversal (Courtesy Dr Dinkar Bhasin, Cardiology Fellow, AIIMS, New Delhi.) Pericardial effusion in patients with cavopulmonary connection is a special clinical situation and is often associated with pleural effusion In the early postoperative period, effusions result from altered ventricular preload and afterload The effusions subside over a period of a few days to weeks.123,124 The presence of effusion during follow-up indicate the possibility of progressive dysfunction of systemic ventricle, regurgitation of atrioventricular valve, and/or development of pulmonary hypertension.125 The management includes thorough evaluation and treatment of all possible causes of a pathologic rise in central venous pressure When present as part of a protein-losing enteropathy, the management is difficult and the prognosis is poor.125 Congenital Anomalies of the Pericardium Congenital Absence of Pericardium Congenital absence of pericardium is rare The absence of pericardium can be complete or partial The pericardial defect may be left-sided or right-sided or, rarely, bilateral Left-sided absence of the pericardium is the most common variant Total absence of pericardium is much more common than partial defects The exact mechanism is not known but is suspected to arise from premature atrophy of the left common cardinal vein affecting the blood supply to the left pleuropericardial membrane during fetal life.126,127 Up to half of such defects are associated with other congenital cardiopulmonary disorders Most cases have no or mild symptoms Cardiac chambers, most commonly the left atrial appendage, can rarely herniate through the defect with subsequent strangulation.126,127 Ventricular herniation, myocardial necrosis, and torsion of great vessels are other potential complications These complications are more common in small partial defects The complete absence of pericardium is less likely to have serious complications The absence of pericardium permits excessive cardiac mobility and the cardiac impulse may be shifted leftward.127 ECG shows nonspecific changes, most common being poor R wave progression and right bundle branch block Chest radiograph (Fig 57.13) shows a leftward shift of cardiac silhouette and absence of right heart border.127 The left cardiac border is straightened and elongated (Snoopy sign) In addition, the space between the aorta and main pulmonary artery is prominent with interposed lung tissue.127 Echocardiography shows distorted cardiac anatomy causing an apparent dilatation of the right ventricle and abnormal septal motion Lack of pericardial restrain results in a characteristic postural change in cardiac position.127,128 Cardiac MRI is diagnostic and helps in prompt detection of complications Surgical repair, by patch closure of the defect, is indicated in cases with active or impending cardiac chamber herniation Enlargement of a small pericardial defect is yet another strategy to prevent cardiac chamber herniation and incarceration.129 Complete absence of pericardium is rarely symptomatic and usually requires no treatment.129 ... DR, diastolic reversal; S, systolic forward wave; SR, systolic reversal (Courtesy Dr Dinkar Bhasin, Cardiology Fellow, AIIMS, New Delhi.) Pericardial effusion in patients with cavopulmonary connection is a special