A 5-day-old male neonate presents with severe cyanosis, poor feeding, and respiratory distress. Vital signs show HR 168 bpm, RR 52/min, BP 52/28 mmHg, SpO2 68% on room air, and temperature 37.2°C. Chest X-ray reveals an "egg-on-string" appearance. Echocardiography confirms transposition of the great arteries with patent foramen ovale allowing right-to-left shunting. The infant has no murmur on auscultation. Which embryologic defect of the conotruncus accounts for this reversal of the aorta and pulmonary artery origins?
- A)Failure of neural crest cells to migrate into the conus cordisGABARITO
- B)Incomplete fusion of the dorsal mesocardium
- C)Insufficient endocardial cushion tissue formation
- D)Abnormal development of the sinus venosus
- E)Failure of the common arterial trunk to septate
Explicação
Transposition of the great arteries results from abnormal neural crest cell migration into the conus cordis and truncus arteriosus during weeks 5-7. Normal conal septation divides the conotruncus into the aorta and pulmonary artery. Defective neural crest migr... Ver explicação completa e trilha adaptativa →