Balancing the circulation: theoretic optimization of pulmonary/systemic flow ratio in hypoplastic left heart syndrome.

摘要: Abstract Objectives. This study examined the effects of pulmonary (Qp)/systemic (Qs) blood flow ratio (Qp/Qs) on systemic oxygen availability in neonates with hypoplastic left heart syndrome, Background. The management syndrome to complex and controversial. Both before after surgical palliation ten transplantation, a univentricle parallel circulations exists. It is generally assumed that balancing best circulation. Methods. We developed mathematical model was based simple uptake lungs whole-body consumption effect varying Qp/Qsratio. An equation derived related key variables cardiac output, venous saturation Qp/Qsratio availability. Results. findings are 1) as increases, increases initially, reaches maximum then decreases; 2) for maximal availability, optimal ≤ 1; 3) decreases Cardiac output or percent saturation, both, increase; 4) critical range Qp/Qs, where supply exceeds basal consumption, decrease; 5) relation between Qp/Qsis very steep when Qp/Qsapproaches this value; 6) low outside Qp/Qsand high within range. Conclusions. analysis provides theoretic basis both circulation suggests evaluating arterial may be useful way determine relative flows. When present, should decreased; conversely, more directed