Impact of ductus arteriosus constriction and restrictive foramen ovale on global hemodynamics for term fetuses with d‐TGA

Abstract

The ductus arteriosus (DA) constriction and restrictive foramen ovale (FO) are known as the leading cause of compromise and death of fetuses with dextro‐transposition of the great arteries (d‐TGA). Although the d‐TGA fetal hemodynamics is of great importance in making diagnosis and management of the congenital heart defect, it remains poorly understood, particularly in terms of abnormal DA and FO. In this study, we developed a closed‐loop 0‐1D multiscale model of the fetal cardiovascular system (CVS) specified for the d‐TGA circulation and conducted a systematic study of the impact of the DA constriction and restrictive FO on fetal hemodynamics. We found that the DA constriction led to a pronounced increase in the pulmonary artery pressure, pulmonary and mitral valve (PV and MV) regurgitation as well as left heart volume; the restrictive FO was responsible for reducing MV E/A ratio, ie, the ratio of peak early filling and late diastolic filling velocities, and PV peak systolic flow (PSV) but could increase both aortic valve (AV) PSV and aortic isthmus systolic index (ISI). Moreover, the amount of blood flowing through the DA was observed equivalent to that through the FO; the influence of DA constriction on the cerebral and placental perfusions are larger than that of the FO. Our results demonstrate that the proposed fetal cardiovascular model may be a useful tool for studying the underlying mechanisms associated with d‐TGA fetal circulation and providing insights into its complex physiology and pathology.

Dextro-transposition of the great arteries in one twin: case reports and literature review

“…In case 2, the D-TGA fetus with intact ventricular septum developed hypoxemia and cyanosis because of a closed foramen ovale, and an emergent atrial septostomy was performed to alleviate her symptoms; in case 3, cyanosis occurred in the D-TGA fetus after birth and was sustained for more than half an hour, although complicated with patent foramen ovale. However, the incidence of restrictive foramen ovale in D-TGA is about 38-50% (15,16), and its prenatal detection is still challenging (7). From these two cases, we hypothesize that gestational age at birth may affect peripheral oxygen saturation of the D-TGA neonate.…”

“…Placental circulation between maternal and fetal systems, shunts of the foramen ovale, and ductus arteriosus and ductus venous guarantees adequate oxygen supply in utero, even in a stressful state. However, hypoxemia and cyanosis may develop once the neonatal circulation begins because of impaired physiologic shunts (7). In case 2, the D-TGA fetus with intact ventricular septum developed hypoxemia and cyanosis because of a closed foramen ovale, and an emergent atrial septostomy was performed to alleviate her symptoms; in case 3, cyanosis occurred in the D-TGA fetus after birth and was sustained for more than half an hour, although complicated with patent foramen ovale.…”

“…Fetal ultrasound is the first-line procedure that indicates D-TGA (13). Its prenatal use can reduce mortality and morbidity because the findings can alert doctors to implement emergent neonatal management strategies or interventions such as balloon atrial septostomy, and further, the outcome and long-term neurocognitive function can also be improved (7,13,14).…”

“…Dextro-transposition of the great arteries (D-TGA) has been reported to account to 4% of all CHD (congenital heart disease) cases (1) and is defined as a swap between the location of the pulmonary artery and the aorta, with the relationship between the atrium and ventricle remaining unchanged (2). The prevalence of D-TGA is 0.02-0.05% of live births (2)(3)(4)(5)(6), and perioperative mortality is about 4% (7,8). Arterial switch operation (ASO) is the common surgical procedure used to treat D-TGA, with a low operation mortality of 2-3% (5,9), long-term benefits (9), and a high survival rate (5,10).…”

Personalized 0D‐1D multiscale hemodynamic modeling and wave dynamics analysis of cerebral circulation for an elderly patient with dementia

“…The 1D governing equations of mass and momentum conservation in the blood vessel are given by Reference 24. where A is the vascular CSA, U is the average axial velocity over the CSA, t is the time, x is the axial coordinate along the vessel, P is the average internal pressure in the vessel over the CSA, μ = 0.0035 Pa·s and is the blood viscosity, ρ = 1050 kg·m −3 and is the blood density, and ξ = 22 and is the viscous friction constant.…”