What characterizes pink tetralogy of Fallot?

Pink tetralogy of Fallot is characterized by a variant of the classic tetralogy of Fallot, where there is a ventricular septal defect but a milder form of pulmonary stenosis or even normal right ventricular outflow. In this case, the oxygen saturation levels in the blood remain relatively normal, resulting in less cyanosis compared to the classic form, which often presents with severe right ventricular outflow obstruction and significant cyanosis.

The correct choice highlights that patients with pink tetralogy of Fallot typically present with mild pulmonary stenosis. This leads to a less turbulent flow and, consequently, less-right-to-left shunting of blood through the ventricular septal defect. The venous blood does not mix as significantly with arterial blood, allowing for improved oxygen saturation. This characteristic of having mild pulmonary stenosis distinguishes it from the more severe forms of tetralogy where oxygen saturation could be significantly affected, leading to cyanotic presentations.

By recognizing that pink tetralogy of Fallot presents with this milder variant, one understands why the clinical presentation is different, both in symptoms and in management strategies. This concept is crucial for practicing perfusionists, as it affects decision-making during surgical interventions and postoperative care of the patient.