What is the primary purpose of performing cardiac catheterization in an infant with a ventricular septal defect (VSD)?

What is the primary purpose of performing cardiac catheterization in an infant with a ventricular septal defect (VSD)?

• A. To evaluate lung function
• B. To help determine the extent of the VSD
• C. To monitor for infection
• D. To assess kidney function

Answer: (B)

The main idea is that cardiac catheterization is used to quantify how large the ventricular septal defect is and how much blood is shunting through it, by directly measuring pressures and oxygen saturations in the heart and blood vessels. This provides precise information about the defect’s size and the hemodynamic impact, including the pulmonary-to-systemic flow ratio and pulmonary vascular resistance. With that data, clinicians can decide whether and when to repair the VSD and what approach to use, while also assessing the risk of future problems like pulmonary hypertension or Eisenmenger syndrome. In contrast, this procedure isn’t primarily a test of lung function, infection surveillance, or kidney function, so those aspects aren’t the main purpose of catheterization in this context.

The main idea is that cardiac catheterization is used to quantify how large the ventricular septal defect is and how much blood is shunting through it, by directly measuring pressures and oxygen saturations in the heart and blood vessels. This provides precise information about the defect’s size and the hemodynamic impact, including the pulmonary-to-systemic flow ratio and pulmonary vascular resistance. With that data, clinicians can decide whether and when to repair the VSD and what approach to use, while also assessing the risk of future problems like pulmonary hypertension or Eisenmenger syndrome.

In contrast, this procedure isn’t primarily a test of lung function, infection surveillance, or kidney function, so those aspects aren’t the main purpose of catheterization in this context.