The most common congenital heart malformation is most often a defect in which structure?

The most common congenital heart malformation is most often a defect in which structure?

• A. Tricuspid atresia
• B. Aortic stenosis
• C. Patent ductus arteriosus
• D. Ventricular septal defect

Answer: (D)

Ventricular septal defect is the most common congenital heart malformation. It results from incomplete formation or fusion of the interventricular septum during heart development, most often in the membranous portion near the outflow tract. When a hole remains between the left and right ventricles, blood shunts from the higher-pressure left ventricle to the right, causing increased pulmonary blood flow that can range from silent to causing loud murmurs and heart failure in infancy. Many small VSDs close spontaneously as the heart matures. Other options involve different structures or circumstances (for example, a valvular or ductal issue) and are not as common as a septal defect.

Ventricular septal defect is the most common congenital heart malformation. It results from incomplete formation or fusion of the interventricular septum during heart development, most often in the membranous portion near the outflow tract. When a hole remains between the left and right ventricles, blood shunts from the higher-pressure left ventricle to the right, causing increased pulmonary blood flow that can range from silent to causing loud murmurs and heart failure in infancy. Many small VSDs close spontaneously as the heart matures. Other options involve different structures or circumstances (for example, a valvular or ductal issue) and are not as common as a septal defect.