Recombinant angiotensin II is an emerging drug therapy for refractory hypotension. Its use is relevant to patients with disruption of the renin–angiotensin–aldosterone system denoted by elevated direct renin levels. We present a child that responded to recombinant angiotensin II in the setting of right ventricular hypertension and multi-organism septic shock.

Amiodarone may be considered for patients with junctional ectopic tachycardia refractory to treatment with sedation, analgesia, cooling, and electrolyte replacements. There are currently no published pediatric data regarding the hemodynamic effects of the newer amiodarone formulation, PM101, devoid of hypotensive agents used in the original amiodarone formulation. We performed a single-center, retrospective, descriptive study from January 2012 to December 2020 in a pediatric ICU. Thirty-three patients were included (22 male and 11 female) between the ages of 1.1 and 1,460 days who developed post-operative junctional ectopic tachycardia or other tachyarrhythmias requiring PM101. Data analysis was performed on hemodynamic parameters (mean arterial pressures and heart rate) and total PM101 (mg/kg) from hour 0 of amiodarone administration to hour 72. Adverse outcomes were defined as Vasoactive-Inotropic Score >20, patients requiring ECMO or CPR, or patient death. There was no statistically significant decrease in mean arterial pressures within the 6 hours of PM101 administration (p > 0.05), but there was a statistically significant therapeutic decrease in heart rate for resolution of tachyarrhythmia (p < 0.05). Patients received up to 25 mg/kg in an 8-hour time for rate control. Average rate control was achieved within 11.91 hours and average rhythm control within 62 hours. There were four adverse events around the time of PM101 administration, with three determined to not be associated with the medication. PM101 is safe and effective in the pediatric cardiac surgical population. Our study demonstrated that PM101 can be used in a more aggressive dosing regimen than previously reported in pediatric literature with the prior formulation.

Understanding blood flow in human body’s cerebral arterial system is of both fundamental and practical significance for prevention and treatment of vascular diseases. The mechanism and treatment for the growth of daughter aneurysm on its mother aneurysm are not yet fully understood. Themain purpose of the present paper is to elucidate the relationships between hemodynamics and the genesis, growth, subsequent rupture of the mother and daughter aneurysm on the cerebral vascular. The intensified stents with different porosities and structures are investigated to reduce the wall shear stress and pressure of mother and daughter aneurysm. The simulation is based on a lattice Boltzmann modeling of non-Newtonian blood flow. A novel stent structurewith “dense in front and sparse in rear” is proposed,which is verified to have good potential to reduce the wall shear stress of both mother and daughter aneurysm. The simulation is based on a lattice Boltzmann modeling of non-Newtonian blood flow. A novel stent structurewith “dense in front and sparse in rear” is proposed,which is verified to have good potential to reduce the wall shear stress of both mother and daughter aneurysm.

A distributed-parameter (one-dimensional) anatomically detailed model for the arterialnetwork of the arm is developed in order to carry out hemodynamics simulations. This workfocuses on the specific aspects related to the model set-up. In this regard, stringentanatomical and physiological considerations have been pursued in order to construct thearterial topology and to provide a systematic estimation of the involved parameters. Themodel comprises 108 arterial segments, with 64 main arteries and 44 perforator arteries,with lumen radii ranging from 0.24 cm – axillary artery- to 0.018 cm – perforatorarteries. The modeling of blood flow in deformable vessels is governed by a well-known setof hyperbolic partial differential equations that accounts for mass and momentumconservation and a constitutive equation for the arterial wall. The variationalformulation used to solve the problem and the related numerical approach are described.The model rendered consistent pressure and flow rate outputs when compared with patientrecords already published in the literature. In addition, an application todimensionally-heterogeneous modeling is presented in which the developed arterial networkis employed as an underlying model for a three-dimensional geometry of a branching pointto be embedded in order to perform local analyses.

The reliable and effective assimilation of measurements and numerical simulations inengineering applications involving computational fluid dynamics is an emerging problem assoon as new devices provide more data. In this paper we are mainly driven by hemodynamicsapplications, a field where the progressive increment of measures and numerical toolsmakes this problem particularly up-to-date. We adopt a Bayesian approach to the inclusionof noisy data in the incompressible steady Navier-Stokes equations (NSE). The purpose isthe quantification of uncertainty affecting velocity and flow related variables ofinterest, all treated as random variables. The method consists in the solution of anoptimization problem where the misfit between data and velocity - in a convenient norm -is minimized under the constraint of the NSE. We derive classical point estimators, namelythe maximum a posteriori – MAP – and the maximum likelihood – ML – ones.In addition, we obtain confidence regions for velocity and wall shear stress, a flowrelated variable of medical relevance. Numerical simulations in 2-dimensional andaxisymmetric 3-dimensional domains show the gain yielded by the introduction of a completestatistical knowledge in the assimilation process.

Background: Exaggerated cardiovascular reactivity to stressful stimuli may be a risk factor for the development of hypertension. The genetic influence on blood pressure (BP) reactivity to stress and its control mechanisms has been receiving considerable support. This study aims at examining the heritability of BP and its intermediate hemodynamic phenotypes to acute stress in a homogeneous Arab population. Methods: Parameters were computed from continuous BP, electrocardiography and impedance cardiography measurements, during rest, word conflict (WCT) and cold pressor (CPT) tests. Heritability estimates (h2) were obtained using the variance components-based approach implemented in the SOLAR software package. Results: Reactivity scores for WCT and CPT increased significantly (P < .05) for systolic (SBP), diastolic (DBP), heart rate (HR), cardiac output (CO), and total peripheral resistance (TPR). They decreased significantly (P < .05) for stroke volume (SV), left ventricular ejection time (LVET), end diastolic (EDI) and cardiac contractility (IC) indices. Univariate analysis detected heritability estimates that ranged from 0.19–0.35 for rest, 0.002–0.40 for WCT and 0.08–0.35 for CPT. Conclusion: In this unique cohort, resting as well as challenged cardiovascular phenotypes are significantly influenced by additive genetic effects. Heritability estimates for resting phenotypes are in a relatively narrow range, while h2 for their reactivity is somewhat broader with lower estimates. Further analyses of this study may offer important opportunities for gene finding in hypertension. What is Known About the Topic: (1) cardiovascular reactivity to stress predicts cardiovascular disease; (2) genetic susceptibility plays an important role in stress reactivity. Family studies using the cold pressure test reported significant heritability for blood pressure. What this Study Adds: (1) this cohort is from five highly consanguineous isolated Arab pedigrees with genetically verified genealogical records and environmental homogeneity; (2) This is the first study to estimate heritability of detailed intermediate hemodynamic phenotypes that make up normal blood pressure.

The parallel implementation of MUPHY, a concurrent multiscale code for large-scale hemodynamic simulations in anatomically realistic geometries, for multi-GPU platforms is presented. Performance tests show excellent results, with a nearly linear parallel speed-up on up to 32GPUs and a more than tenfold GPU/CPU acceleration, all across the range of GPUs. The basic MUPHY scheme combines a hydrokinetic (Lattice Boltzmann) representation of the blood plasma, with a Particle Dynamics treatment of suspended biological bodies, such as red blood cells. To the best of our knowledge, this represents the first effort in the direction of laying down general design principles for multiscale/physics parallel Particle Dynamics applications in non-ideal geometries. This configures the present multi-GPU version of MUPHY as one of the first examples of a high-performance parallel code for multiscale/physics biofluidic applications in realistically complex geometries.

The spatial domain of Molecular Dynamics simulations is usually a regular box that can be easily divided in subdomains for parallel processing. Recent efforts aimed at simulating complex biological systems, like the blood flow inside arteries, require the execution of Parallel Molecular Dynamics (PMD) in vessels that have, by nature, an irregular shape. In those cases, the geometry of the domain becomes an additional input parameter that directly influences the outcome of the simulation. In this paper we discuss the problems due to the parallelization of MD in complex geometries and show an efficient and general method to perform MD in irregular domains.