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2011-01-13-14 Left atrial isomerism © Averyanov
Left atrial isomerism

Andrew Averyanov
, MD., Alexandre Krasnov, MD., Irina Glazkova, MD. 

Donetsk`s regional specialized center of medical genetic and prenatal diagnosis, Ukraine.


Case report
A 30-year-old women (G7 P3) was referred to our center at 33 weeks of gestation. Her family history of congenital diseases was negative as well as her personal history and she didn’t undergo any chemotherapy treatment. She delivered 3 healthy children and 3 of her pregnancies were spontaneous abortions.  Her first trimester scan at 13 weeks of gestation did not show any abnormalities.
Our ultrasound examination at 33 weeks revealed the following findings:


  • Mesocardia (the axis of the interventricular septum was almost anteroposterior)
  • Atrioventricular canal, incomplete form
  • Hypoplasia of the aortic arch, coarctation of the aorta
  • Interruption of the inferior vena cava with azygos continuation
  • Persistent left superior vena cava

Central nervous system
  • Corpus callosum agenesis
  • Dandy-Walker variant

  • Flat profile, depressed nasal bridge
  • Nasal bone hypoplasia
  • Maxillary micrognathia,  relative mandibular prognathism
  • Low set and malformed ears
  • Prominent lips, broad cheeks
  • Microphtalmia
  • Narrow, tower-shaped skull (craniosynostosis)

  • Left kidney hypoplasia

Our ultrasound findings can be divided into two groups: 1) typical collection of cardiac and central nervous system anomalies for left isomerism, 2) typical collection of facial and skull dysmorphisms for Carpenter syndrome. Our diagnosis based on the ultrasound findings was Left atrial isomerism associated with Carpenter syndrome.

The parents opted for the termination of the pregnancy due to an adverse prognosis for the fetus. Unfortunately, parents did not wish for autopsy or genetic testing. They agreed to have their own karyotyping done and both had a normal karyotype. Clinical examination of the fetus confirmed our diagnosis. 

Images 1,2: 4-chamber view, note that the heart axis is deviated towards the midline. (*)indicate atrial appendages. Atrioventricular valves are inserted at the same level of the interventricular septum.

Images 3,4
: Image 4 shows a hypoplastic aortic arch. Image 4 shows ascending aorta.

Images 5,6
: Image 5 shows a 3-vessel view showing pulmonary artery (PA), aorta (Ao) and persistent left superior vena cava (left SVC). Image 6 shows transverse view of the persistent left superior vena cava, aorta and azygos vein.

Images 7,8: Sagittal view of the chest and abdomen, there is an azygos vein (AzV) running parallel and posterior to the aorta (Ao).

Images 9 - 12: Images 9,10 show a fetal profile, note the depressed nasal bridge, hypoplastic nasal bone, turricephalic skull, prominent maxilla and lips, low set ears. Image 11 shows the face with low set ears, depressed nasal bridge, large nostrils, prominent lips and broad cheeks. Image 12 shows a microphthalmia (arrow).


Images 13,14: Image 13 shows the absence of the corpus callosum and pericallosal artery. Image 14 shows an axial view of the brain, arrows indicate anterior horns, a dilated third ventricle which is displaced upwards and absent cavum septum pellucidum.

Images 15,16: Image 15 shows the cisterna magna and the vermis hypoplasia. Image 16 shows a stomach, gallbladder and umbilical vein.

Image 17: 33 weeks, image shows a longitudinal view of the right kidney showing the right kidney hypoplasia.  


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