Zusammenfassung der Ressource
transposition of the great arteries
- right to left shunt
- =discordant
ventriculo-arterial
connection
- aorta connected to right ventricle
- pulmonary artery
connected to left
ventricle
- blue blood is returned to body
- & pink blood
returns to
lungs
- i.e. 2 parallel circulations
- incompatible with life
- unless there is mixing of the blood btw them
- e.g. by VSD, ASD, PDA
- Clinical features
- Sx
- cyanosis
- main sx
- profond and life-threatening
- usually presents on day 2 of life
- ductal closure-> marked
reduction in mixing of sat and
desat blood
- less severe and
presentation
delayed if there is
more mixing of
blood
- from assoc anomalies e.g. ASD
- physical signs
- cyanosis
- always present
- loud & single S2
- usually no murmur
- but maybe systolic murmur
- from increased flow
or stenosis within
left ventricular
(pulmonary) outflow
tract
- Ix
- CXR
- classic findings
- narrow
upper
mediastinum
- due to ant-post
relationship of great
vessels & narrow
vascular pedicle
- cardiac
shadow:
egg on side
appearance
- due to hypertrophied right ventricle
- increased pulmonary vasc markings
- due to
increased
pulmonary
blood flow
- ECG
- usually normal
- Echo
- to show abnormal arterial
connections & assoc
abnormalities
- essential
- Mx
- in sick cyanosed neonate, key is to improve mixing
- must maintain patency of ductus arteriosus
- w/ prostaglandin infusion
- balloon atrial septostomy
- life-saving
- done in 20% of cases
- catheter with inflatable balloon at tip
- passed through
umbilical/femoral v through into
right atrium and formaen ovale
- balloon inflated in left atrium & pulled back through atrial septum
- atrial septum torn, so foramen ovale valve left incompetent
- so sys and pulmonary venous blood can mix
- surgery
- all pts w/ TGA need this
- usually arterial switch procedure
- done in neonatal period (esp 1st few days of life)
- pul artery & aorta are
transected above arterial
valves & switched over