Children with acyanotic congenital heart disease frequently develop respiratory difficulties such as atelectasis, pneumonia, or infantile lobar emphysema. In some cases, the cause of the respiratory difficulty is compression of the tracheobronchial tree by hypertensive dilated pulmonary arteries, since this type of heart disease frequently demonstrates large left-to-right intracardiac shunts. Sites of predilection for compression include the left main bronchus, the left upper lobe bronchus, the junction of the right bronchus intermedius and right middle lobe bronchus, and the left side of the distal trachea. Cardiac anomalies which predispose to this type of compression include ventricular septal defect, patent ductus arteriosus, interruption of the aortic arch, and tetralogy of Fallot. Pulmonary arteriopexy may relieve the tracheobronchial compression.