Heterotaxy Syndrome

  • Etiology: congenital
  • Left atrial isomerism / polysplenia
    — Cardiac abnormalities (less severe) – aortic stenosis, atrial septal defect / ventricular septal defect
    — Vascular abnormalities – bilateral atrial connection of pulmonary veins, inferior vena cava interruption
    — Pulmonary abnormalities – bilateral hyparterial bronchus (bronchus is anterio-inferior to pulmonary artery) and bilateral bilobed lungs
    — Gastrointestinal abnormalities – polysplenia, midline liver, stomach on either side, bowel rotation, biliary atresia
    — Clinical: less severe congenital heart disease, presents later, associated with biliary atresia
  • Right atrial isomerism / asplenia
    — Cardiac abnormalities (severe) – common AV canal, double inlet left ventricle / double outlet right ventricle, absent coronary sinus
    — Vascular abnormalities – totally anomalous pulmonary venous return – always present – 50% extracardiac, discordant ventriculoarterial connections, pulmonary atresia / stenosis, normal inferior vena cava
    — Pulmonary abnormalities – bilateral eparterial bronchus (bronchus is posterio-superior to pulmonary artery) and bilateral trilobed lungs
    — Gastrointestinal abnormalities – asplenia, midline / right side liver, abnormal bowel rotation in 70%
    — Clinical: severe cyanosis, severe congenital heart disease, susceptible to infection

Cases of Heterotaxy Syndrome

Upper GI of malrotation without midgut volvulus in heterotaxy
AP image from an upper GI shows the ligament of Treitz to be in the right upper quadrant. There is no evidence of duodenal obstruction. The proximal jejunum is also in the right upper quadrant. There is also gastroesophageal reflux.
CXR of heterotaxy syndrome and upper GI of malrotation without midgut volvulus
CXR AP (above) shows the cardiac apex to be in the right hemithorax and the gastric bubble to be in the left upper quadrant. AP image from an upper GI (below) shows the ligament of Treitz to be in the right upper quadrant. There is no evidence of duodenal obstruction. The proximal jejunum is also in the right upper quadrant.