What hemodynamic change occurs with an increase in systemic vascular resistance (SVR) in a child with cyanotic heart disease?

The correct choice highlights an important aspect of hemodynamics in the context of cyanotic heart disease. When systemic vascular resistance (SVR) increases, it creates a greater opposition to blood flow in the systemic circulation. In patients with cyanotic heart disease, there may already be an abnormal connection between the systemic and pulmonary circulation, such as a right-to-left shunt, where deoxygenated blood bypasses the lungs.

As SVR increases, the pressure in the systemic circulation rises, which can lead to a situation where more blood is shunted back into the pulmonary artery. This change can be explained by the need for the heart to accommodate the increased systemic pressures. When more blood returns to the pulmonary artery, this can result in a transient increase in pulmonary blood flow in some cases. However, it is critical to recognize that the overall ability of the pulmonary system to oxygenate the blood would still be compromised due to the nature of the heart defect involved.

Therefore, in the context of cyanotic heart disease, an increase in systemic vascular resistance typically leads to increased blood flow into the pulmonary artery as the pressure dynamics shift, highlighting the complex relationships in pediatric cardiovascular physiology. Understanding these mechanisms is crucial for managing patients with congenital heart disease effectively.