TY - CHAP M1 - Book, Section TI - Tetralogy of Fallot A1 - Doherty, Gerard M. PY - 2010 T2 - Quick Answers Surgery AB - • A congenital heart lesion that decreases pulmonary arterial blood flow resulting in a right-to-left shunt• Cyanosis and decreased oxygen delivery causes compensatory polycythemia (Hct > 70%) and spontaneous thrombosis• Exercise, acidosis, pain worsens cyanosis, can cause hypoxic spells• Squatting increases systemic resistance, causing increased pulmonary flow and oxygen saturation• β-Blockers (decreases spasm), fluid intake, HCO3 administration, norepinephrine (increases systemic resistance) may help decrease hypoxia• Clubbing due to proliferation of capillaries and AV fistulas in extremities• Bronchial and mediastinal arteries enlarge• Ductus arteriosus maintains flow to lungs during fetal development• Alprostadil early can allow time for optimization before definitive treatment• 4 anomalies: 1. Ventricular septal defect (VSD)2. Pulmonary stenosis or atresia3. Overriding aorta4. RV hypertrophy• Pulmonary stenosis may involve infundibulum, valve, or main pulmonary artery (PA)• Extent of pulmonary atresia/stenosis has wide spectrum of severity• Pulmonary flow depends on aortopulmonary collaterals, can be extensive enough to cause congestive heart failure• Spasm of infundibular muscle may cause unconciousness and death SN - PB - The McGraw-Hill Companies CY - New York, NY Y2 - 2024/10/03 UR - accesssurgery.mhmedical.com/content.aspx?aid=58102325 ER -