RT Book, Section
A1 Doherty, Gerard M.
SR Print(0)
ID 58102325
T1 Tetralogy of Fallot
T2 Quick Answers Surgery
YR 2010
FD 2010
PB The McGraw-Hill Companies
PP New York, NY
SN 
LK accesssurgery.mhmedical.com/content.aspx?aid=58102325
RD 2024/04/19
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