Surgical Anatomy: Embryology of the CV and GI systems

Congenital cardiac disorders, with an incidence of 1/1000 newborns, belong to the most frequent birth defects. Chromosomal aberrations are frequently associated with heart abnormalities.

1. Right Heart obstruction

Pulmonary stenosis (PS)

Obstructions can occur at various levels in the right side of the heart or in the pulmonary outflow path. Pure obstructions do not result in a mixing of the blood but cause a massive additional strain on the ventricles because they have to pump against increased resistance.

1. Patent Ductus Arteriosus (PDA)

2. Atrial Septal Defect (ASD)

3. Ventricular Septal Defect (VSD)

4. Atrio-Ventricular Septal Defect (AV Canal)

In cardiac abnormalities with right-left shunts oxygen-poor blood gets from the right half of the heart into the left side and thus into the systemic circulatory system. In most of the defects with right-left shunts the physiologic shunts present before birth remain functional because no reversal of pressure happens following birth.

I. Transposition of the great vessels (TGA)

Cyanosis is a blue coloration of the skin and mucous membranes due to the presence of greater than, or equal to, 2.5 g/dL of deoxygenated hemoglobin in blood vessels near the skin surface.