Ventricular septal defect clinical manifestations correlate with what physiologic factor?

• A. Age
• B. Blood pressure
• C. Pulmonary edema
• D. Degree of shunting

Answer: (D)

The main factor that shapes how a ventricular septal defect presents is the amount of blood that shunts from the left ventricle to the right ventricle. The bigger the defect and the greater the pressure difference, the larger the left-to-right shunt. That increased shunting raises pulmonary blood flow and left-heart volume load, producing symptoms such as tachypnea, poor feeding, failure to thrive, and eventually pulmonary edema or heart failure in larger defects. Small shunts may be asymptomatic or cause only a murmur, while large shunts lead to more evident cardiovascular compromise. Age and blood pressure influence presentation timing and hemodynamics to some extent, but the clinical manifestations correlate best with the degree of shunting.