Hemodynamic Changes Research Articles

A Comparative Study of Epidural 0.75% Ropivacaine with Dexmedetomidine and 0.75% Ropivacaine Alone in Infra Umbilical Surgeries

Background: Different adjuvants are currently being employed alongside local anesthetics to extend the duration of pain relief during and after epidural block procedures for infra-umbilical surgeries. Dexmedetomidine is a recently popular neuroaxial adjuvant that acts as an extremely specific α2 adrenergic agonist. The purpose of this research is to evaluate and contrast the impacts of combining epidural giving of 0.75% ropivacaine with dexmedetomidine to the effects of using 0.75% ropivacaine alone. The focus was on evaluating the cardiovascular, sedative with analgesics potentiating The facets of these treatments.Methods: The research was randomized and studied in a double-blind, prospective fashion. It comprised 50 patients from the The individuals included in this study were classified as undertaking lower limb procedures were those who met the following criteria: Female, the age from 20 to 65, and holding American Society of Anesthesiologists Grades I and II. Informed agreement was given before the start of the study. Randomly, participants were divided into two groups, each consisting of 25 individuals. A 15 mL ropivacaine solution containing 0.75% was utilized to administrate epidural anesthesia to a group I (n = 25). In contrast, group II (n = 25) received the same 15 mL ropivacaine solution supplemented with 0.6 μg/kg of dexmedetomidine. The study compared two groups in terms of their hemodynamic changes and block characteristics. These characteristics included the time it took for analgesia to start at T10, the peak level of sensory perception analgesia achieved, the time it took for the sensory and motor block to reach their maximum levels, the time it took for the block to regress at the dermatome S1, and the time required to administer the initial quantity rescue effort analgesics to be administered within a 24-hour period.Results: Sedation score (p = 0.001), motor block intensity (p 0.001), and onset of action (p 0.001) were all significantly greater in the dexmedetomidine group. Additionally, motor block duration (p 0.001) was significantly longer. No significant differences were observed in the occurrence of maximal pain relief, low BP, or slow HR (p > 0.05), according to the study. There was a negligible and comparable occurrence of adverse effects (such as vertigo, tremor, and SpO2<90%) across all categories (p > 0.05). Conclusion: The research revealed noteworthy distinctions commencing with the inhibition of neural functions differs between the dexmedetomidine and ropivacaine groups, with dexmedetomidine producing more intense sustained motor block and sensory block. Both groups had greater sedation scores.

Effects of different nitric oxide synthases on pulmonary and systemic hemodynamics in hypoxic stress rat model.

Under hypoxia, exaggerated compensatory responses may lead to acute mountain sickness. The excessive vasodilatory effect of nitric oxide (NO) can lower the hypoxic pulmonary vasoconstriction (HPV) and peripheral blood pressure. While NO is catalyzed by various nitric oxide synthase (NOS) isoforms, the regulatory roles of these types in the hemodynamics of pulmonary and systemic circulation in living hypoxic animals remain unclear. Therefore, this study aims to investigate the regulatory effects of different NOS isoforms on pulmonary and systemic circulation in hypoxic rats by employing selective NOS inhibitors and continuously monitoring hemodynamic parameters of both pulmonary and systemic circulation. Forty healthy male Sprague-Dawley (SD) rats were randomly divided into four groups: Control group (NG-nitro-D-arginine methyl ester, D-NAME), L-NAME group (non-selective NOS inhibitor, NG-nitro-L-arginine methyl ester), AG group (inducible NOS inhibitor group, aminoguanidine), and 7-NI group (neurological NOS inhibitor, 7-nitroindazole). Hemodynamic parameters of rats were monitored for 10 min after inhibitor administration and 5 min after induction of hypoxia [15% O2, 2200 m a. sl., 582 mmHg (76.5 kPa), Xining, China] using the real-time dynamic monitoring model for pulmonary and systemic circulation hemodynamics invivo. Serum NO concentrations and blood gas analysis were measured. Under normoxia, mean arterial pressure and total peripheral vascular resistance were increased, and ascending aortic blood flow and serum NO concentration were decreased in the L-NAME and AG groups. During hypoxia, pulmonary arterial pressure and pulmonary vascular resistance were significantly increased in the L-NAME and AG groups. This compensatory mechanism activated by inducible NOS and endothelial NOS effectively counteracts the pulmonary hemodynamic changes induced by hypoxic stress. It plays a crucial role in alleviating hypoxia-induced pulmonary arterial hypertension.

Quantitative evaluation using carotid ultrasonography-based high-frame-rate vector flow imaging in patients with low carotid stenosis.

To explore the role of quantitative evaluation using carotid ultrasonography (US)-based high-frame-rate vector flow (V Flow) imaging in patients with low carotid stenosis. This single-centre cross-sectional study consecutively recruited volunteers without carotid plaque and patients with low carotid stenosis from August 2022 to May 2023. Patients were divided into symptomatic and asymptomatic groups according to their head CT or MRI results within 8 weeks. All V Flow imaging examinations were performed using a Mindray Resona R9 US system. The wall shear stress (WSS) values, oscillatory shear index (OSI) values, and turbulence (Tur) indexes in the normal common carotid artery (CCA), normal carotid bifurcation (CB), and on the upstream and downstream surface of carotid plaque were measured. Pearson Chi-square test and Fisher exact test were used for counting data according to their type. For measurement data, independent sample t test and non-parametric rank sum test were used. The results proved that patients have higher WSS values and Tur indexes of CB than volunteers, and higher WSS values were detected on the surface of the plaques in symptomatic patients. What's more, the downstream side of the plaque was more vulnerable to plaque rupture than the upstream side due to more dynamic blood flow. Therefore, carotid US-based high-frame-rate V Flow imaging provides reliable mechanical biomarkers for assessing the haemodynamic change in patients with low stenosis. Our study may provide a new imaging tool for monitoring the progression of atherosclerosis and aiding the management of early atherosclerotic patients. Our study firstly investigated the difference of V Flow parameters on the surface of carotid plaques between symptomatic and asymptomatic patients with low carotid stenosis, which is expected to provide haemodynamic information and the mechanical basis for plaque rupture.

A Non-Inferiority Study of the Speed and Success of Nasotracheal Intubation in Maxillofacial Surgeries Using Macintosh Direct Laryngoscope versus Sanyar® Video Laryngoscope

Background: The recently developed blade design of the Sanyar® video laryngoscope yields an exceptionally precise visualization of the larynx, thereby easing the process of tracheal intubation. Objectives: A non-inferiority clinical investigation, to assess the efficacy of the Sanyar® as compared to the Macintosh® direct laryngoscope for nasotracheal intubation in the context of maxillofacial surgeries. Methods: 78 patients for maxillofacial surgery were divided randomly into two groups and intubated through the nose using either the Sanyar® or Macintosh® laryngoscope after anesthesia was induced. The study measured intubation time and secondary objectives included success rate, attempts, and hemodynamic changes in two groups. Results: 40 eligible patients in the Sanyar® and 38 in the Macintosh® group were involved. Of all, 42(53.8%) were men and 36(46.2%) were women. The average age of patients in the Sanyar® and Mackintosh groups was (31.62±13.41) and (30.81±10.89), respectively. 39(98%) of the Sanyar® group and 33(86%) of the Macintosh® group had successful laryngoscopy and intubation, with a P-value<0.034. Sanyar® group had a significantly shorter intubation time than Macintosh® (P-value<0.001). Hemodynamic changes before and after laryngoscopy and intubation had no significant differences between the two groups. Conclusion: The Sanyar® video laryngoscope reduced the time of nasal tracheal intubation in maxillofacial surgery compared to direct laryngoscopy and improved the success rate of the first intubation attempt.

The Effect of Deferoxamine and Vitamin C Supplementation on Ferritin and CRP Levels in COVID-19 Patients

Background: Today, the COVID19 pandemic is one of the most important health system challenges in the world, which doesn’t have specific treatment yet. It includes a wide range of respiratory and non-respiratory signs and symptoms, that lead to hospitalization and intensive care units. Methods: In this study, 78 patients in two groups of 39 patients were included. The case group included 39 COVID19 patients who had specified sign in CT scans and factors of viral infection, high serum ferritin, increased inflammatory factor in the blood. There were two intervention groups (receiving deferoxamine and vitamin C) and the control group (receiving only official protocol drugs of the country). All patients were admitted to the ICU of Shohada-e-Tajrish Hospital and underwent complete cardiorespiratory monitoring. All changes in Spo2, hemodynamics, serum ferritin and CRP were recorded before the study. Results: This study presented that improved patient had lower ferritin levels than those who were still ill. In addition, prescribing deferoxamine as an adjunct to vitamin C can prevent cytokine storms that was effective for improving the patients with COVID19. Conclusion: In conclusion. According to the role of deferoxamine and vitamin C in significantly reducing inflammatory factors of ferritin and CRP, they can be used as an adjunctive therapy in patients with COVID19.

The Effect of Deferoxamine and Vitamin C Supplementation on Ferritin and CRP Levels in COVID-19 Patients

Background: Today, the COVID19 pandemic is one of the most important health system challenges in the world, which doesn’t have specific treatment yet. It includes a wide range of respiratory and non-respiratory signs and symptoms, that lead to hospitalization and intensive care units. Methods: In this study, 78 patients in two groups of 39 patients were included. The case group included 39 COVID19 patients who had specified sign in CT scans and factors of viral infection, high serum ferritin, increased inflammatory factor in the blood. There were two intervention groups (receiving deferoxamine and vitamin C) and the control group (receiving only official protocol drugs of the country). All patients were admitted to the ICU of Shohada-e-Tajrish Hospital and underwent complete cardiorespiratory monitoring. All changes in Spo2, hemodynamics, serum ferritin and CRP were recorded before the study. Results: This study presented that improved patient had lower ferritin levels than those who were still ill. In addition, prescribing deferoxamine as an adjunct to vitamin C can prevent cytokine storms that was effective for improving the patients with COVID19. Conclusion: In conclusion. According to the role of deferoxamine and vitamin C in significantly reducing inflammatory factors of ferritin and CRP, they can be used as an adjunctive therapy in patients with COVID19.

Altered brain perfusion and oxygen levels relate to sleepiness and attention in post-COVID syndrome.

Persisting neurological symptoms after COVID-19 affect up to 10% of patients and can manifest in fatigue and cognitive complaints. Based on recent evidence, we evaluated whether cerebral hemodynamic changes contribute to post-COVID syndrome (PCS). Using resting-state functional magnetic resonance imaging, we investigated brain perfusion and oxygen level estimates in 47 patients (44.4 ± 11.6 years; F:M = 38:9) and 47 individually matched healthy control participants. Group differences were calculated using two-sample t-tests. Multivariable linear regression was used for associations of each regional perfusion and oxygen level measure with cognition and sleepiness measures. Exploratory hazard ratios were calculated for each brain metric with clinical measures. Patients presented with high levels of fatigue (79%) and daytime sleepiness (45%). We found widespread decreased brain oxygen levels, most evident in the white matter (false discovery rate adjusted-p-value (p-FDR) = 0.038) and cortical grey matter (p-FDR = 0.015). Brain perfusion did not differ between patients and healthy participants. However, delayed patient caudate nucleus perfusion was associated with better executive function (p-FDR = 0.008). Delayed perfusion in the cortical grey matter and hippocampus were associated with a reduced risk of daytime sleepiness (hazard ratio (HR) = 0.07, p = 0.037 and HR = 0.06, p = 0.034). Decreased putamen oxygen levels were associated with a reduced risk of poor cognitive outcome (HR = 0.22, p = 0.019). Meanwhile, lower thalamic oxygen levels were associated with a higher risk of cognitive fatigue (HR = 6.29, p = 0.017). Our findings of lower regional brain blood oxygen levels suggest increased cerebral metabolism in PCS, which potentially holds a compensatory function. These hemodynamic changes were related to symptom severity, possibly representing metabolic adaptations.

Calcineurin Inhibitor in NEuRoloGically deceased donors to decrease kidney delayed graft function study: study protocol of the CINERGY Pilot randomised controlled trial

IntroductionMost solid organ transplants originate from donors meeting criteria for death by neurological criteria (DNC). Within the organ donor, physiological responses to brain death increase the risk of ischaemia reperfusion...

Chronic inflammation with microglia senescence at basal forebrain: impact on cholinergic deficit in Alzheimer's brain haemodynamics.

Cholinergic innervation in the brain is involved in modulating neurovascular function including cerebral blood flow haemodynamics in response to neuronal activity. Cholinergic deficit is associated with pathophysiology in Alzheimer's disease, albeit the aetiology remains to be clarified. In the current study, neocortex cerebral blood flow response to acetylcholine was evaluated by Laser-Doppler Flowmetry (LDF) in 3xTgAD Alzheimer's disease model) and wild-type mice of two age groups. The peak of cerebral blood flow to acetylcholine (i.v.) from baseline levels (% ΔrCBF) was higher in young 3xTgAD versus in wild-type mice (48.35; 95% CI:27.03-69.67 versus 22.70; CI:15.5-29.91, P < 0.05); this was reversed in old 3xTgAD mice (21.44; CI:2.52-40.35 versus 23.25; CI:23.25-39). Choline acetyltransferase protein was reduced in neocortex, while cerebrovascular reactivity to acetylcholine was preserved in young 3×TgAD mice. This suggests endogenous acetylcholine deficit and possible cholinergic denervation from selected cholinergic nuclei within the basal forebrain. The early deposition of tauopathy moieties (mutant hTau and pTau181) and its coincidence in cholinergic cell clusters (occasionaly), were observed at the basal forebrain of 3xTgAD mice including substantia innominate, nucleus Basalis of Meynert and nucleus of horizontal limb diagonal band of Broca. A prominent feature was microglia interacting tauopathy and demonstrated a variety of morphology changes particularly when located in proximity to tauopathy. The microglia ramified phenotype was reduced as evaluated by the ramification index and Fractal analysis. Increased microglia senescence, identified as SASP (senescence-associated secretory phenotype), was colocalization with p16Ink4ɑ, a marker of irreversible cell-cycle arrest in old 3xTgAD versus wild-type mice (P = 0.001). The p16Ink4ɑ was also observed in neuronal cells bearing tauopathy within the basal forebrain of 3xTgAD mice. TNF-ɑ, the pro-inflammatory cytokine elevated persistently in microglia (Pearson's correlation coefficient = 0.62) and the loss of cholinergic cells in vulnerable basal forebrain environment, was indicated by image analysis in 3xTgAD mice, which linked to the cholinergic deficits in neocortex rCBF haemodynamics. Our study revealed the early change of CBF haemodynamics to acetylcholine in 3xTgAD model. As a major effector of brain innate immune activation, microglia SASP with age-related disease progression is indicative of immune cell senescence, which contributes to chronic inflammation and cholinergic deficits at the basal forebrain. Targeting neuroinflammation and senescence may mitigate cholinergic pathophysiology in Alzheimer's disease.

Sound waves and solutions: Point-of-care ultrasonography for acute kidney injury in cirrhosis

This article delves into the intricate challenges of acute kidney injury (AKI) in cirrhosis, a condition fraught with high morbidity and mortality. The complexities arise from distinguishing between various causes of AKI, particularly hemodynamic AKI, in cirrhotic patients, who experience hemodynamic changes due to portal hypertension. The term "hepatocardiorenal syndrome" is introduced to encapsulate the intricate interplay among the liver, heart, and kidneys. The narrative emphasizes the often-overlooked aspect of cardiac function in AKI assessments in cirrhosis, unveiling the prevalence of cirrhotic cardiomyopathy marked by impaired diastolic function. The conventional empiric approach involving volume expansion and vasopressors for hepatorenal syndrome is critically analyzed, highlighting potential risks and variable patient responses. We advocate for a nuanced algorithm for AKI evaluation in cirrhosis, prominently featuring point-of-care ultrasonography (POCUS). POCUS applications encompass assessing fluid tolerance, detecting venous congestion, and evaluating cardiac function.

Cerebral hemodynamics underlying ankle force sense modulated by high-definition transcranial direct current stimulation.

This study aimed to investigate the effects of high-definition transcranial direct current stimulation on ankle force sense and underlying cerebral hemodynamics. Sixteen healthy adults (8 males and 8 females) were recruited in the study. Each participant received either real or sham high-definition transcranial direct current stimulation interventions in a randomly assigned order on 2 visits. An isokinetic dynamometer was used to assess the force sense of the dominant ankle; while the functional near-infrared spectroscopy was employed to monitor the hemodynamics of the sensorimotor cortex. Two-way analyses of variance with repeated measures and Pearson correlation analyses were performed. The results showed that the absolute error and root mean square error of ankle force sense dropped more after real stimulation than after sham stimulation (dropped by 23.4% vs. 14.9% for absolute error, and 20.0% vs. 10.2% for root mean square error). The supplementary motor area activation significantly increased after real high-definition transcranial direct current stimulation. The decrease in interhemispheric functional connectivity within the Brodmann's areas 6 was significantly correlated with ankle force sense improvement after real high-definition transcranial direct current stimulation. In conclusion, high-definition transcranial direct current stimulation can be used as a potential intervention for improving ankle force sense. Changes in cerebral hemodynamics could be one of the explanations for the energetic effect of high-definition transcranial direct current stimulation.

Tachyarrhythmias in congenital heart disease.

The prevalence of congenital heart disease (CHD) in adult patients has risen with advances in diagnostic and surgical techniques. Surgical modifications and hemodynamic changes increase the susceptibility to arrhythmias, impacting morbidity and mortality rates, with arrhythmias being the leading cause of hospitalizations and sudden deaths. Patients with CHD commonly experience both supraventricular and ventricular arrhythmias, with each CHD type associated with different arrhythmia patterns. Macroreentrant atrial tachycardias, particularly cavotricuspid isthmus-dependent flutter, are frequently reported. Ventricular arrhythmias, including monomorphic ventricular tachycardia, are prevalent, especially in patients with surgical scars. Pharmacological therapy involves antiarrhythmic and anticoagulant drugs, though data are limited with potential adverse effects. Catheter ablation is preferred, demanding meticulous procedural planning due to anatomical complexity and vascular access challenges. Combining imaging techniques with electroanatomic navigation enhances outcomes. However, risk stratification for sudden death remains challenging due to anatomical variability. This article practically reviews the most common tachyarrhythmias, treatment options, and clinical management strategies for these patients.

Perivascular Adipose Tissue and Uterine Artery Adaptations to Pregnancy.

Pregnancy is characterized by longitudinal maternal, physiological adaptations to support the development of a fetus. One of the cardinal maternal adaptations during a healthy pregnancy is a progressive increase in uterine artery blood flow. This facilitates sufficient blood supply for the development of the placenta and the growing fetus. Regional hemodynamic changes in the uterine circulation, such as a vast reduction in uterine artery resistance, are mainly facilitated by changes in uterine artery reactivity and myogenic tone along with remodeling of the uterine arteries. These regional changes in vascular reactivity have been attributed to pregnancy-induced adaptations of cell-to-cell communication mechanisms, with an emphasis on the interaction between endothelial and vascular smooth muscle cells. Perivascular adipose tissue (PVAT) is considered the fourth layer of the vascular wall and contributes to the regulation of vascular reactivity in most vascular beds and most species. This review focuses on mechanisms of uterine artery reactivity and the role of PVAT in pregnancy-induced maternal vascular adaptations, with an emphasis on the uterine circulation.

Delivering care to women with congenital heart disease: the role of clinical nurse specialist

Congenital heart disease is now the most common reason for women to attend a high-risk joint cardiac–obstetric clinic. With advances in medical care and surgical techniques, most children born with congenital heart disease reach childbearing age and have a good prognosis for long-term survival with a good quality of life. Pregnancy remains a major life event for these women, posing additional risks with the potential for severe morbidity and mortality. The hemodynamic changes induced by pregnancy can unmask undiagnosed congenital heart disease or exacerbate pre-existing conditions. Therefore, specialist care is essential for a successful pregnancy outcome. Women with complex congenital heart disease embarking on pregnancy need the support of a multidisciplinary team, including cardiologists, obstetricians, anaesthetists, midwives and adult congenital heart disease clinical nurse specialists. Clinical nurse specialists in particular play a crucial role in coordinating, supporting, educating and advocating for the mother and fetus through preconception, pregnancy, the puerperium and beyond.

Evaluation of Flavonoid-rich Fraction of Portulaca Grandiflora Aerial Part Extract in Atherogenic Diet-induced Atherosclerosis.

Portulaca grandiflora is a tiny, upright herb that contains a variety of chemical components, including alkaloids, glycosides, mucilage, proteins, tannins, flavonoids, saponins, polysaccharides, and triterpenoids possessing properties that may help with atherosclerosis. The reported pharmacological properties of Portulaca grandiflora are antioxidant, antidiabetic, antiasthmatic, antibacterial, antiulcer and anti-inflammatory properties. The yield of methanol extract is higher than that of ethanol and acetone, and its phytoconstituents, like flavonoids and polyphenols, and has potent antioxidant properties. In order to determine the effectiveness ofPortulaca grandiflora methanol extract fraction against high-fat diet (HFD)-induced hyperlipidemia, hemodynamic change, antioxidant levels, and vascular dysfunction in rats, a study was carried out on a flavonoid-rich methanol extract fraction of the aerial part of Portulaca grandiflora Hook. This method involves a study of 30 days involving male Wistar rats (240-250 g) (n=5) that were fed with an Ath diet. Study groups were divided into (i) The Control Group, (ii) the Diseases Control Group, (iii) Disease + Standard drug (Atorvastatin 20mg/kg, orally, (iv) Disease + Test Extract dose 1 (Portulaca grandiflora 200mg/kg orally), and (v) Disease + Test Extract dose 2 (Portulaca grandiflora 400mg/kg orally). Both the test drug Portulaca grandiflora and the standard drug Atorvastatin were given orally for 30 days. At the end of the study, blood samples were taken to measure the serum lipid profile, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and levels of oxidative tissue stress. Hemodynamic parameters and aortic staining were performed. Portulaca grandiflora treatment improved the lipid profile and considerably reduced oxidative stress levels. Aortic staining examination revealed a marked reduction in atherosclerotic lesions. These results revealed that Portulaca grandiflora is an effective treatment approach in preventing atherosclerotic lesion progression, which is attributed to its protection against oxidative stress and various enzymatic activities in the Atherogenic model.

Oral Clonidine-Based Strategy to Reduce Opiate Use During Cooling for Neonatal Encephalopathy: An Observational Study

To determine whether an enteral, clonidine-based sedation strategy (CLON) during therapeutic hypothermia (TH) for hypoxic-ischemic encephalopathy (HIE) would decrease opiate use, while maintaining similar short-term safety and efficacy profiles to a morphine-based strategy (MOR). This was a single-center, observational study conducted at a level IV neonatal intensive care unit from January 1, 2017, to October 1, 2021. From April 13, 2020, to August 13, 2020, MOR was transitioning to CLON. Thus, patients receiving TH for HIE were grouped to MOR (before April 13, 2020) and CLON (after August 13, 2020). We calculated the total and rescue morphine milligram equivalent (MME)/ kg (primary outcome) and frequency of hemodynamic changes (secondary outcome) for both groups. MOR and CLON groups (74 and 25 neonates, respectively) had similar baseline characteristics and need for rescue sedative intravenous infusion (21.6% MOR and 20% CLON). Both, MME/ kg and need for rescue opiates (combined bolus and infusions) were higher in MOR than CLON (p < 0.001). As days in TH advanced, a lower percentage of CLON patients needed rescue opiates (92% on day 1 to 68% on day 3). MOR patients received a higher cumulative dose of dopamine and more frequently required a second inotrope and hydrocortisone for hypotension. MOR had a lower respiratory rate during TH (p=0.01 vs. CLON). Our CLON protocol is non-inferior to MOR, maintaining perceived effectiveness and hemodynamic safety, with an apparently reduced need for opiates and inotropes.

Virtual Shape-Editing of Patient-Specific Vascular Models Using Regularized Kelvinlets.

Cardiovascular diseases, and the interventions performed to treat them, can lead to changes in the shape of patient vasculatures and their hemodynamics. Computational modeling and simulations of patient-specific vascular networks are increasingly used to quantify these hemodynamic changes, but they require modifying the shapes of the models. Existing methods to modify these shapes include editing 2D lumen contours prescribed along vessel centerlines and deforming meshes with geometry-based approaches. However, these methods can require extensive by-hand prescription of the desired shapes and often do not work robustly across a range of vascular anatomies. To overcome these limitations, we develop techniques to modify vascular models using physics-based principles that can automatically generate smooth deformations and readily apply them across different vascular anatomies. We adapt Regularized Kelvinlets, analytical solutions to linear elastostatics, to perform elastic shape-editing of vascular models. The Kelvinlets are packaged into three methods that allow us to artificially create aneurysms, stenoses, and tortuosity. Our methods are able to generate such geometric changes across a wide range of vascular anatomies. We demonstrate their capabilities by creating sets of aneurysms, stenoses, and tortuosities with varying shapes and sizes on multiple patient-specific models. Our Kelvinlet-based deformers allow us to edit the shape of vascular models, regardless of their anatomical locations, and parametrically vary the size of the geometric changes. These methods will enable researchers to more easily perform virtual-surgery-like deformations, computationally explore the impact of vascular shape on patient hemodynamics, and generate synthetic geometries for data-driven research.

Myocardial Bridge and Atherosclerosis, an Intimal Relationship.

This review investigates the relationship between myocardial bridges (MBs), intimal thickening in coronary arteries, and Atherosclerotic cardiovascular disease. It focuses on the role of mechanical forces, such as circumferential strain, in arterial wall remodeling and aims to clarify how MBs affect coronary artery pathology. MBs have been identified as influential in modulating coronary artery intimal thickness, demonstrating a protective effect against thickening within the MB segment and an increase in thickness proximal to the MB. This is attributed to changes in mechanical stress and hemodynamics. Research involving arterial hypertension models and vein graft disease has underscored the importance of circumferential strain in vascular remodeling and intimal hyperplasia. Understanding the complex dynamics between MBs, mechanical strain, and vascular remodeling is crucial for advancing our knowledge of coronary artery disease mechanisms. This could lead to improved management strategies for cardiovascular diseases, highlighting the need for further research into MB-related vascular changes.

The impact of hypovolemia and PEEP on recirculation in venovenous ECMO: an experimental porcine model

BackgroundRecirculation is a common problem in venovenous extracorporeal membrane oxygenation (VV ECMO) and may limit the effect of ECMO treatment due to less efficient blood oxygenation or unfavorable ECMO and ventilator settings. The impact of hypovolemia and positive end expiratory pressure (PEEP) on recirculation is unclear and poorly described in guidelines, despite clinical importance. The aim of this study was to investigate how hypovolemia, autotransfusion and PEEP affect recirculation in comparison to ECMO cannula distance and circuit flow.MethodsIn anesthetized and mechanically ventilated pigs (n = 6) on VV ECMO, we measured recirculation fraction (RF), changes in recirculation fraction (∆RF), hemodynamics and ECMO circuit pressures during alterations in PEEP (5 cmH2O vs 15 cmH2O), ECMO flow (3.5 L/min vs 5.0 L/min), cannula distance (10–14 cm vs 20–26 cm intravascular distance), hypovolemia (1000 mL blood loss) and autotransfusion (1000 mL blood transfusion).ResultsRecirculation increased during hypovolemia (median ∆RF 43%), high PEEP (∆RF 28% and 12% with long and short cannula distance, respectively), high ECMO flow (∆RF 49% and 28% with long and short cannula distance, respectively) and with short cannula distance (∆RF 16%). Recirculation decreased after autotransfusion (∆RF − 45%).ConclusionsIn the present animal study, hypovolemia, PEEP and autotransfusion were important determinants of recirculation. The alterations were comparable to other well-known factors, such as ECMO circuit flow and intravascular cannula distance. Interestingly, hypovolemia increased recirculation without significant change in ECMO drainage pressure, whereas high PEEP increased recirculation with less negative ECMO drainage pressure. Autotransfusion decreased recirculation. The findings are interesting for clinical studies.

Quantitative Analysis of Hemodynamic Changes in Branch Arteries Covered by Flow Diverters.

Understanding post-treatment hemodynamic alterations and their association with the patency of covered branch arteries is limited. This study aims to identify hemodynamic changes after flow diverter stenting and investigate their correlation with the patency status of covered branch arteries. All patients treated with pipeline embolization device for anterior cerebral artery aneurysms at our center between 2016 and 2020 were screened for inclusion. Quantitative digital subtraction angiography was used to analyze changes in hemodynamic parameters pre- and post-stenting. The patency status of covered branch arteries after stenting was categorized as either patent or flow impairment (defined as artery stenosis or occlusion). A total of 71 patients, encompassing 89 covered branch arteries, were enrolled. Flow impairment was observed in 11.2% (10/89) of the branches. The mean transit time and full width at half maximum (FWHM) in covered branches were significantly prolonged post-stenting (P = .004 and .023, respectively). Flow-impaired branch arteries exhibited hemodynamic shifts contrary to those in patent branch arteries. Specifically, flow-impaired branches showed marked reductions in time to peak, FWHM, and mean transit time (decreases of 32.8%, 32.6%, and 29%, respectively; P = .006, .002, and .002, respectively). Further multivariate analysis revealed that reductions in FWHM in the branches (odds ratio = 0.97, 95% CI: 0.95-0.99, P = .007) and smoking (odds ratio = 14.5, 95% CI: 1.39-151.76, P = .026) were independent predictors of flow impairment of covered branches. Pipeline embolization device stenting can cause a reduction in blood flow in branch arteries. Compared with patent branches, flow-impaired branches exhibit an increase in blood flow velocity after stenting. Smoking and ΔFWHM in the covered branches indicate flow impairment.