Abstract
The immature cardiovascular system of very preterm infants predisposes them to low systemic blood flow during the first week of life, a state that may be damaging to multiple organ systems. There are many treatment strategies for the maintenance of cardiovascular equilibrium in these infants, each with its own advantages and risks. Caregivers are responsible for assessing the circulatory status of each patient and evaluating the effectiveness of interventions aimed at maintaining adequate systemic blood flow. Therefore, it is important to have an understanding of the mechanics of transitional circulation, the relationship between blood pressure and systemic blood flow, and the therapies used to treat infants with compromised organ perfusion.