A child born with Tetralogy of Fallot often squats. The practitioner knows that squatting helps to:

In children born with Tetralogy of Fallot, which consists of four specific heart defects, squatting is a behavioral response that can help alleviate symptoms related to decreased blood flow to the lungs. This condition often leads to "tet spells," where there is a decrease in oxygenated blood available to the body.

When the child squats, it increases systemic vascular resistance (afterload), which can lead to a reduction in the right-to-left shunting of blood through the ventricular septal defect. By increasing the resistance, more blood is directed toward the pulmonary circulation instead of being shunted away from it. This helps improve oxygenation by allowing a greater volume of blood to flow to the pulmonary arteries where it can receive oxygen.

While options related to heart rate, blood pressure in the legs, and lower back pain touch on physiological responses that might occur in various contexts, they do not directly address the immediate effect that squatting has on the hemodynamics specifically related to transplanting blood to the pulmonary circulation in the context of Tetralogy of Fallot. In this way, squatting serves as a compensatory mechanism to manage the child's condition effectively.