scholarly journals Human fetal hearts with tetralogy of Fallot have altered fluid dynamics and forces

2018 ◽  
Vol 315 (6) ◽  
pp. H1649-H1659 ◽  
Author(s):  
Hadi Wiputra ◽  
Ching Kit Chen ◽  
Elias Talbi ◽  
Guat Ling Lim ◽  
Sanah Merchant Soomar ◽  
...  
Keyword(s):  
Blood Flow ◽  
Tetralogy Of Fallot ◽  
Congenital Heart ◽  
Elevated Pressure ◽  
Patient Specific ◽  
Shear Stresses ◽  
Additional Energy ◽  
Congenital Heart Malformations ◽  
Wall Shear ◽  
Heart Malformations

Studies have suggested the effect of blood flow forces in pathogenesis and progression of some congenital heart malformations. It is therefore of interest to study the fluid mechanic environment of the malformed prenatal heart, such as the tetralogy of Fallot (TOF), especially when little is known about fetal TOF. In this study, we performed patient-specific ultrasound-based flow simulations of three TOF and seven normal human fetal hearts. TOF right ventricles (RVs) had smaller end-diastolic volumes (EDVs) but similar stroke volumes (SVs), whereas TOF left ventricles (LVs) had similar EDVs but slightly increased SVs compared with normal ventricles. Simulations showed that TOF ventricles had elevated systolic intraventricular pressure gradient (IVPG) and required additional energy for ejection but IVPG elevations were considered to be mild relative to arterial pressure. TOF RVs and LVs had similar pressures because of equalization via ventricular septal defect (VSD). Furthermore, relative to normal, TOF RVs had increased diastolic wall shear stresses (WSS) but TOF LVs were not. This was caused by high tricuspid inflow that exceeded RV SV, leading to right-to-left shunting and chaotic flow with enhanced vorticity interaction with the wall to elevate WSS. Two of the three TOF RVs but none of the LVs had increased thickness. As pressure elevations were mild, we hypothesized that pressure and WSS elevation could play a role in the RV thickening, among other causative factors. Finally, the endocardium surrounding the VSD consistently experienced high WSS because of RV-to-LV flow shunt and high flow rate through the over-riding aorta. NEW & NOTEWORTHY Blood flow forces are thought to cause congenital heart malformations and influence disease progression. We performed novel investigations of intracardiac fluid mechanics of tetralogy of Fallot (TOF) human fetal hearts and found essential differences from normal hearts. The TOF right ventricle (RV) and left ventricle had similar and elevated pressure but only the TOF RV had elevated wall shear stress because of elevated tricuspid inflow, and this may contribute to the observed RV thickening. TOF hearts also expended more energy for ejection.

Blood Flow Manipulation in the Aorta With Coarctation and Arch Narrowing for Pediatric Subjects

2020 ◽  
Vol 88 (2) ◽  
Author(s):  
Yuxi Jia ◽  
Kumaradevan Punithakumar ◽  
Michelle Noga ◽  
Arman Hemmati
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Aortic Arch ◽  
Flow Direction ◽  
Upper Body ◽  
Patient Specific ◽  
Shear Stresses ◽  
Wall Shear

Abstract The characteristics of blood flow in an abnormal pediatric aorta with an aortic coarctation and aortic arch narrowing are examined using direct numerical simulations and patient-specific boundary conditions. The blood flow simulations of a normal pediatric aorta are used for comparison to identify unique flow features resulting from the aorta geometrical anomalies. Despite flow similarities compared to the flow in normal aortic arch, the flow velocity decreases with an increase in pressure, wall shear stress, and vorticity around both anomalies. The presence of wall shear stresses in the trailing indentation region and aorta coarctation opposing the primary flow direction suggests that there exist recirculation zones in the aorta. The discrepancy in relative flowrates through the top and bottom of the aorta outlets, and the pressure drop across the coarctation, implies a high blood pressure in the upper body and a low blood pressure in the lower body. We propose using flow manipulators prior to the aortic arch and coarctation to lower the wall shear stress, while making the recirculation regions both smaller and weaker. The flow manipulators form a guide to divert and correct blood flow in critical regions of the aorta with anomalies.

The influence of multi-stenosis in the left coronary artery subjected to the variable blood flow rate

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sarfaraz Kamangar ◽  
N. Ameer Ahamad ◽  
N. Nik-Ghazali ◽  
Ali E. Anqi ◽  
Ali Algahtani ◽  
...  
Keyword(s):  
Blood Flow ◽  
Coronary Artery ◽  
Flow Rate ◽  
Left Coronary Artery ◽  
Upstream Region ◽  
Recirculation Region ◽  
Patient Specific ◽  
Shear Stresses ◽  
Content Type ◽  
Wall Shear

PurposeCoronary artery disease (CAD) is reported as one of the most common sources of death all over the world. The presence of stenosis (plaque) in the coronary arteries results in the restriction of blood supply, leading to myocardial infarction. The current study investigates the influence of multi stenosis on hemodynamic properties in a patient-specific left coronary artery.Design/methodology/approachA three-dimensional model of the patient-specific left coronary artery was reconstructed based on computed tomography (CT) scan images using MIMICS-20 software. The diseased model of the left coronary artery was investigated, having the narrowing of 90% and 70% of area stenosis (AS) at the left anterior descending (LAD) and left circumflex (LCX), respectively.FindingsThe results indicate that the upstream region of stenosis experiences very high pressure for 90% AS during the systolic period of the cardiac cycle. The pressure drops maximum as the flow travels into the stenotic zone, and the high flow velocities were observed across the 90% AS. The higher wall shear stresses occur at the stenosis region, and it increases with the increase in the flow rate. It is found that the maximum wall shear stress across 90% AS is at the highest risk for rupture. A recirculation region immediately after the stenosis results in the further development of stenosis.Originality/valueThe current study provides evidence that there is a strong effect of multi-stenosis on the blood flow in the left coronary artery.

Tetralogy of Fallot in a neonate following intrauterine exposure to valproic acid

1996 ◽  
Vol 6 (3) ◽  
pp. 232-234
Author(s):  
Wendy A. Stewart ◽  
R. Michael Giuffre
Keyword(s):  
Valproic Acid ◽  
Tetralogy Of Fallot ◽  
Congenital Heart ◽  
Ventricular Septal Defects ◽  
Septal Defects ◽  
Fetal Valproate Syndrome ◽  
Intrauterine Exposure ◽  
Congenital Heart Malformations ◽  
Heart Malformations

SummaryValproic acid is a known teratogen, giving rise to a typical craniofacial appearance, the fetal valproate syndrome. Congenital heart malformations in this syndrome have most commonly been ventricular septal defects. We report a child with familial craniosynostosis, and tetralogy of Fallot, following intrauterine exposure to valproic acid.

FEATURES OF INTENSIVE CARE OF CONGENITAL HEART MALFORMATIONS IN NEWBORNS

2020 ◽  
Vol 99 (3) ◽  
pp. 200-207
Author(s):  
D.O. Ivanov ◽  
◽  
K.V. Pshenisnov ◽  
Y.S. Aleksandrovich ◽  
◽  
...  
Keyword(s):  
Intensive Care ◽  
Congenital Heart ◽  
Congenital Heart Malformations ◽  
Heart Malformations

scholarly journals Congenital heart malformations: sequential angiographic analysis

1981 ◽  
Vol 137 (4) ◽  
pp. 673-681 ◽  
Author(s):  
JG Arciniegas ◽  
B Soto ◽  
HC Coghlan ◽  
LM Bargeron
Keyword(s):  
Congenital Heart ◽  
Congenital Heart Malformations ◽  
Heart Malformations

scholarly journals Quantifying blood flow dynamics during cardiac development: demystifying computational methods

2018 ◽  
Vol 373 (1759) ◽  
pp. 20170330 ◽  
Author(s):  
Katherine Courchaine ◽  
Sandra Rugonyi
Keyword(s):  
Blood Flow ◽  
Congenital Heart ◽  
Cardiac Development ◽  
Three Dimensional ◽  
Flow Dynamics ◽  
Cardiovascular Development ◽  
Flow Conditions ◽  
Congenital Heart Malformations ◽  
Blood Flow Dynamics ◽  
Altered Blood

Blood flow conditions (haemodynamics) are crucial for proper cardiovascular development. Indeed, blood flow induces biomechanical adaptations and mechanotransduction signalling that influence cardiovascular growth and development during embryonic stages and beyond. Altered blood flow conditions are a hallmark of congenital heart disease, and disrupted blood flow at early embryonic stages is known to lead to congenital heart malformations. In spite of this, many of the mechanisms by which blood flow mechanics affect cardiovascular development remain unknown. This is due in part to the challenges involved in quantifying blood flow dynamics and the forces exerted by blood flow on developing cardiovascular tissues. Recent technologies, however, have allowed precise measurement of blood flow parameters and cardiovascular geometry even at early embryonic stages. Combined with computational fluid dynamics techniques, it is possible to quantify haemodynamic parameters and their changes over development, which is a crucial step in the quest for understanding the role of mechanical cues on heart and vascular formation. This study summarizes some fundamental aspects of modelling blood flow dynamics, with a focus on three-dimensional modelling techniques, and discusses relevant studies that are revealing the details of blood flow and their influence on cardiovascular development. This article is part of the Theo Murphy meeting issue ‘Mechanics of development’.

Letter to the Editor

PEDIATRICS ◽  
1982 ◽  
Vol 70 (2) ◽  
pp. 328-328
Author(s):  
Louis E. Bartoshesky ◽  
Hermine Pashayan
Keyword(s):  
Birth Weight ◽  
Congenital Heart ◽  
Single Case ◽  
Case Reports ◽  
In Utero ◽  
Normal Male ◽  
In Utero Exposure ◽  
Congenital Heart Malformations ◽  
Male Karyotype ◽  
Heart Malformations

We would agree with both writers that there were certain features of the child described in our report that were not typical of the so-called fetal hydantoin syndrome, particularly the birth weight. It is certainly true that single case reports do nothing more than suggest possible associations between malformations and in utero exposure, but much information has been accumulated associating clefts and congenital heart malformations with phenytoin. The baby described had a normal male karyotype. Attempts were made to do karyotyping on tissue obtained at autopsy but were unsuccessful.

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