Sections View Full Chapter Figures Tables Videos 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 GET ACCESS TO THIS RESOURCE Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth Get Free Access Through Your Institution Contact your institution's library to ask if they subscribe to McGraw-Hill Medical Products. Access My Subscription GET ACCESS TO THIS RESOURCE Subscription Options Pay Per View Timed Access to all of AccessPediatrics 24 Hour $34.95 (USD) Buy Now 48 Hour $54.95 (USD) Buy Now Best Value AccessPediatrics Full Site: One-Year Individual Subscription $595 USD Buy Now View All Subscription Options