Heart Development

A 2-week-old female infant presents with cyanosis, a single loud S2, and a systolic ejection murmur. Echocardiography reveals tetralogy of Fallot (TOF) with a large ventricular septal defect, overriding aorta, right ventricular hypertrophy, and pulmonary stenosis. The parents ask which embryological process went wrong. Which of the following best explains the pathogenesis of TOF?

A 3-day-old male neonate born to a 28-year-old primigravida presents with severe cyanosis and respiratory distress. On examination, the infant is deeply cyanosed, with a single loud S2 and a systolic ejection murmur at the left upper sternal border. Chest X-ray shows an 'egg-on-string' appearance with decreased pulmonary vascular markings. Echocardiography confirms anteroposterior transposition of the great arteries with an intact ventricular septum. Which embryological defect in the truncus arteriosus division is responsible for this condition?

Which of the following structures is derived from the truncus arteriosus?

A 3-day-old neonate presents with cyanosis and poor feeding. Echocardiography reveals a single arterial trunk arising from the heart, overriding both ventricles, with a single arterial valve. The pulmonary arteries originate from the lateral wall of this trunk. Which embryological defect is responsible for this condition, and what is the most appropriate immediate next step in management?

Failure of the interventricular septum to fuse during cardiac development results in which of the following defects?