Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ Key Features ++ Cyanosis, initially without associated respiratory distress Failure to increase PaO2 with supplemental oxygen Causes Transposition of the great vessels Total anomalous pulmonary venous return Truncus arteriosus (some types) Tricuspid atresia Pulmonary atresia Critical pulmonary stenosis +++ Clinical Findings ++ Hallmark of many of these lesions is cyanosis without associated respiratory distress In most of these infants, tachypnea develops over time either +++ Diagnosis ++ Comparing the blood gas or oxygen saturation in room air to that in 100% FIO2 can be helpful Failure of PaO2 or SaO2 to increase suggests cyanotic heart disease Note: A PaO2, if feasible, is the preferred measure Saturation in the newborn may be misleadingly high despite pathologically low PaO2 due to the left-shifted oxyhemoglobin dissociation curve seen with fetal hemoglobin Many cases are diagnosed antenatally by ultrasound Chest radiograph with decreased lung markings suggests right heart obstruction, while increased lung markings suggest transposition or pulmonary venous obstruction Chest radiograph typically shows a small to normal heart size with marked pulmonary edema Infants with right-sided heart obstruction (pulmonary and tricuspid atresia, critical pulmonary stenosis, and some forms of truncus arteriosus) have decreased lung markings on chest radiographs and, depending on the severity of hypoxia, may develop metabolic acidemia Those lesions with an underdeveloped right-sided heart will have left-sided predominance on electrocardiography Echocardiography confirms diagnosis +++ Treatment ++ Early stabilization includes supportive therapy as needed (eg, intravenous glucose, oxygen, ventilation for respiratory failure, and vasopressor support) Specific therapy includes infusions of prostaglandin E1 (0.0125–0.025 μg/kg/min) to maintain ductal patency Your Access profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Password? Forgot Username? Sign in via OpenAthens Sign in via Shibboleth