The Pathophysiology of Pulmonary Vascular Disease Associated with Congenital Cardiac Lesions

Hopkins, Richard A.

doi:10.1007/978-1-4613-8634-6_3

Cited by 9 publications

(1 citation statement)

References 131 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These results implicate an alternative form of network organization at the bifurcation and network level different from that previously supposed by universal network theories that assume a fixed homogeneous adult arterial bifurcation design of ␤ Ϸ 1 and 2.0 Ͻ x Ͻ 2.8 for the several adult species that have been studied (16,34). The configuration of fetal bifurcations confirms a hypothesis made by Hopkins (31) that the perinatal pulmonary circulation dissipates hydraulic energy in a manner that is quite different than other stages of pulmonary growth and development and different organ systems (31,37). However, whereas Hopkins addressed a particular mechanism related to pulsatile power dissipation in the viscoelastic vessel wall, this study identifies an underlying organizational form of structural reactivity (23) that was not previously anticipated by any previous theory of bifurcation de-sign (41,43,73).…”

Section: Discussionsupporting

confidence: 71%

Form and function of fetal and neonatal pulmonary arterial bifurcations

Bennett

Eldridge

Zaghi

et al. 2000

American Journal of Physiology-Heart and Circulatory Physiology

View full text Add to dashboard Cite

Bifurcation is a basic form of vascular connection. It is composed of a parent vessel of diameter d(0), and two daughter vessels, d(1) and d(2), where d(0) > d(1) >/= d(2). Optimal values for the bifurcation area ratio, beta = (d(1)(2) + d(2)(2))/d(0)(2), and the junction exponent, x, in d(0)(x) = d(1)(x) + d(2)(x), are postulated to be universal in nature. However, we have hypothesized that the perinatal pulmonary arterial circulation is an exception. Arterial diameters were measured in pulmonary vascular casts of a fetal lamb (140 days gestation/145 days term) and a neonatal lamb (1 day old). The values for beta and x were evaluated in 10,970 fetal and 846 neonatal bifurcations sampled from the proximal and intermediate arterial regions. Mean values and confidence intervals (CI) for the fetus were beta = 0.890 (0.886-0.895 CI) and x = 1.75 (1.74-1.76 CI); and for the newborn were beta = 0.913 (0.90-0.93 CI) and x = 1. 79 (1.75-1.82 CI). These values are significantly different from Murray's law (beta > 1, x = 3) or the West-Brown-Enquist law (beta = 1, x = 2). Therefore, perinatal pulmonary bifurcation design appears to be distinctive and exceptional. The decreasing cross-sectional area with branching leads to the hemodynamic consequence of shear stress amplification. This structural organization may be important for facilitating vascular development at low flow rates; however, it may be the origin of unstable reactivity if elevated blood flow and pressure occurs.

show abstract