What is the most common congenital heart defect in children?

• A. ASD
• B. Coarctation
• C. VSD
• D. PDA

Answer: (C)

Ventricular septal defect is the most common congenital heart defect. It arises when the wall separating the heart’s two lower chambers doesn’t form completely, allowing blood to flow from the left ventricle to the right ventricle. This left-to-right shunt increases blood flow to the lungs and can range from tiny defects that close on their own to large defects that cause heart failure in infancy. Because it occurs more frequently than other structural heart problems, it is the typical CHD you’ll see first in pediatric practice. Some VSDs are detected by a harsh holosystolic murmur at the left lower sternal border, though small defects may be asymptomatic. Diagnosis is confirmed with echocardiography. Management varies by size and symptoms: many small VSDs close spontaneously, while larger ones may require surgical repair or device closure.