What sequence of events characterizes the workload on the right side of the heart in Tetralogy of Fallot?

In Tetralogy of Fallot, the workload on the right side of the heart is characterized by a combination of increased resistance to flow and decreased oxygenation. The anatomical defects present in this condition include a ventricular septal defect (VSD), pulmonary outflow tract obstruction (often caused by infundibular stenosis), an aorta that overrides the ventricular septal defect, and right ventricular hypertrophy.

In this scenario, the right ventricle faces increased workload due to two main factors. First, the pulmonary outflow tract obstruction means that the right ventricle has to generate higher pressures to pump blood into the pulmonary artery. This results in increased resistance to flow from the right ventricle. Secondly, because of the right-to-left shunt (often occurring due to the combination of the VSD and the narrowing of the outflow tract), deoxygenated blood can mix with oxygenated blood, leading to decreased overall oxygen saturation in the systemic circulation.

Therefore, the situation combines increased resistance resulting from the structural heart defects and decreased oxygenation due to inadequate oxygen exchange in the lungs. All these elements contribute to the overall workload experienced by the right side of the heart in Tetralogy of Fallot, making "all of