Hemodynamic Comparison Research Articles

Hemodynamic comparison of transcatheter aortic valve replacement with the SAPIEN 3 Ultra versus SAPIEN 3: The HomoSAPIEN registry.

ObjectivesThe study aims to compare the hemodynamic and clinical outcomes of the SAPIEN 3 Ultra (S3‐Ultra) with the SAPIEN 3 (S3) system in patients who underwent transfemoral transcatheter aortic valve replacement (TF‐TAVR).BackgroundThe new balloon‐expandable S3‐Ultra system incorporates new features to reduce paravalvular leakage (PVL). However, the data after the S3‐Ultra implantation is very limited.MethodsA total of 282 consecutive patients who underwent TF‐TAVR with the S3‐Ultra and the S3 were evaluated. The primary outcome of this study was to compare the incidence of ≥mild PVL after the S3‐Ultra and S3 implantation.ResultsBetween June 2017 and November 2019, 141 patients with the S3‐Ultra and 141 patients with the S3 were identified with similar baseline and preprocedural imaging characteristics (mean age: 79.6 ± 6.7 years and mean aortic annulus area: 492.5 ± 91.2 mm2). In total, 83 patients (29.4%) were treated with 29‐mm valve. Predischarge echocardiography demonstrated a significantly lower incidence of ≥mild PVL (the total cohort: 7.2 vs. 22.3%, p < .001, and the cohort excluding 29‐mm valve: 4.0 vs. 21.4%, p = .03) for the S3‐Ultra. The S3‐Ultra system, especially 20‐, 23‐, and 26‐mm valve, was associated with significantly lower risk of ≥mild PVL compared with the S3 system in multivariate analysis. There were no significant differences in clinical outcomes at 30‐day between these groups, except for the lower incidence of major vascular complication (4.5 vs. 11.4%, p = .05) in patients with the S3‐Ultra.ConclusionsIn this registry, the S3‐Ultra system performed superiorly to the S3, as demonstrated by reduced ≥mild PVL, with comparable safety.

Comparison of Patient Haemodynamics and Cost Analysis between Ketamine and Dexmedetomidine Used for Endoscopic Retrograde Cholangiopancreatography

Comparison of Patient Haemodynamics and Cost Analysis between Ketamine and Dexmedetomidine Used for Endoscopic Retrograde Cholangiopancreatography

Qualitative and Quantitative Comparison of Hemodynamics Between MRI Measurement and CFD Simulation on Patient-specific Cerebral Aneurysm – A Review

The significant progress in computer innovation technique, computational fluid dynamics (CFD) has been applied for real applications on patient-specific hemodynamics and extensively used to study cerebral aneurysm rupture. In addition, the computational study with representative blood vessel configuration has become a great tool in providing comprehensive information on geometry, the flow field of blood and wall shear stress (WSS). Generally, the numerical simulations have an expected problem on the specification of the exact boundary conditions which leads to unphysical numerical solutions. Therefore, this paper tends to find out whether CFD simulation manages to obtain precise and better predictions of hemodynamics patterns at present time especially for phase-contrast magnetic resonance imaging (PC-MRI) in terms of the velocity flow field and WSS distribution. Several research articles are included and their qualitative and quantitative results on hemodynamics have been compared. Both MRI measurement and CFD simulation have reasonably good agreement on velocity flow fields and a detailed spiral recirculating flow pattern can be observed in CFD simulation as compared to MRI measurement instead. However, CFD simulation has overestimated the WSS, especially at the maximum WSS location. The CFD simulation is capable to achieve good agreement on velocity flow fields with MRI measurement, yet the result for WSS distribution has to be further improved and justified with consistent assumptions and techniques.

Comparison of pulmonary circulation hemodynamics and respiratory mechanics induced by drowning with equal volume of freshwater and seawater in sheep: a randomized controlled study

To compare the effects of freshwater and seawater drowning on sheep's pulmonary circulation hemodynamics and respiratory mechanics. According to the random number table method, healthy crossbred sheep were divided into freshwater drowning group (n = 12) and seawater drowning group (n = 12). 30 mL/kg of freshwater or seawater was infused respectively through trachea for approximately 5 minutes. Before the drowning, immediately after drowning, and 30, 60, 120 minutes after drowning, the systemic circulation hemodynamic parameters [heart rate (HR), mean arterial pressure (MAP), cardiac output (CO)] were monitored by pulse indicator continuous cardiac output (PiCCO); the respiratory parameters were obtained through the ventilator, including tidal volume (VT), lung compliance (Cdyn), oxygenation index (PaO2/FiO2), peak airway pressure (Ppeak)]; PiCCO and the right heart floating catheter (Swan-Ganz catheter) was used to measure pulmonary hemodynamic parameters [pulmonary systolic pressure (PAS), pulmonary diastolic pressure (PAD), pulmonary artery wedge pressure (PAWP), and extravascular lung water (EVLW)]. The animals were sacrificed at the end of the experiment, and the amount of residual water in the respiratory tract was measured; the pathological changes in the lung tissue were observed by hematoxylin-eosin (HE) staining. (1) Systemic circulation hemodynamics: compared with the values before drowning, HR, MAP, and CO at the time of immediately after drowning in both freshwater and seawater were significantly increased and peaked. In addition, all indicators in the freshwater drowning group were significantly higher than those in the seawater drowning group [HR (bpm): 170.75±1.87 vs. 168.67±2.27, MAP (mmHg, 1 mmHg = 0.133 kPa): 172.92±1.62 vs. 159.42±3.18, CO (L/min): 13.27±0.71 vs. 10.33±0.73, all P < 0.05]. (2) Respiratory parameters: compared with values before drowning, PaO2/FiO2, VT, and Cdyn decreased immediately in both freshwater and seawater drowning groups, Ppeak was significantly increased; in addition, the values in the seawater drowning group were decreased or increased more significantly than freshwater drowning group [PaO2/FiO2 (mmHg): 37.83±1.99 vs. 60.42±5.23, VT (mL): 86.25±7.66 vs. 278.75±9.67, Cdyn (mL/cmH2O): 8.86±0.33 vs. 23.02±0.69, Ppeak (cmH2O, 1 cmH2O = 0.098 kPa): 42.17±2.69 vs. 17.67±1.15, all P < 0.01]. In addition, PaO2/FiO2 in the freshwater drowning group was gradually increased over time, while the seawater group continued to decline. (3) Pulmonary circulation hemodynamic parameters: PAS, PAD, PAWP at the time of immediately after drowning in both freshwater and seawater groups were significantly higher than before drowning; in addition, the freshwater drowning group was significantly higher than the seawater drowning group [PAS (mmHg): 34.58±2.87 vs. 26.75±1.66, PAD (mmHg): 27.25±1.22 vs. 16.75±0.87, PAWP (mmHg): 27.83±1.85 vs. 11.75±1.82, all P < 0.01]. Thereafter, PAS and PAD in the freshwater drowning group gradually decreased, while the parameters in the seawater drown group continued to increase. PAWP gradually decreased after freshwater or seawater drowning, and recovered to pre-drowning levels 120 minutes after drowning and 30 minutes after drowning, respectively. EVLW continued to increase after freshwater drowning, reaching a peak at 30 minutes, and then decreased, until 120 minutes after drowning was still significantly higher than that before drowning (mL/kg: 10.73±1.27 vs. 7.67±0.69, P < 0.01); EVLW could not be measured. (4) Residual water in the respiratory tract: residual water in the freshwater drowning group was significantly less than that in the seawater drowning group (mL: 164.33±25.21 vs. 557.33±45.23, P < 0.01). (5) HE staining: partial alveolar atrophied in the freshwater drowning group, some alveolar spaces were broken, alveolar spaces and alveolar cavity showed a little powdery substance deposition; it was noted that alveolar expanded in the seawater drowning group, alveolar spaces were broken and bleeding and edema were obvious in the interstitial space. The effect of seawater drowning on the respiratory mechanics and pulmonary circulation of animals is more obvious than that of freshwater drowned animals, and the amount of residual water in the respiratory tract is also significantly more than that of freshwater drowned animals.

4D Flow MRI hemodynamic benchmarking of surgical bioprosthetic valves

PurposeWe exploited 4-dimensional flow magnetic resonance imaging (4D Flow), combined with a standardized in vitro setting, to establish a comprehensive benchmark for the systematic hemodynamic comparison of surgical aortic bioprosthetic valves (BPVs). Materials and methods4D Flow analysis was performed on two small sizes of three commercialized pericardial BPVs (Trifecta™ GT, Carpentier-Edwards PERIMOUNT Magna and Crown PRT®). Each BPV was tested over a clinically pertinent range of continuous flow rates within an in vitro MRI-compatible system, equipped with pressure transducers. In-house 4D Flow post-processing of the post-valvular velocity field included the quantification of BPV effective orifice area (EOA), transvalvular pressure gradients (TPG), kinetic energy and viscous energy dissipation. ResultsThe 4D Flow technique effectively captured the 3-dimensional flow pattern of each device. Trifecta exhibited the lowest range of velocity and kinetic energy, maximized EOA (p < 0.0001) and minimized TPGs (p ≤ 0.015) if compared with Magna and Crown, these reporting minor EOA difference s (p ≥ 0.042) and similar TPGs (p ≥ 0.25). 4D Flow TPGs estimations strongly correlated against ground-truth data from pressure transducers; viscous energy dissipation proved to be inversely proportional to the fluid jet penetration. ConclusionThe proposed 4D Flow analysis pinpointed consistent hemodynamic differences among BPVs, highlighting the not negligible effect of device size on the fluidynamic outcomes. The efficacy of non-invasive 4D Flow MRI protocol could shed light on how standardize the comparison among devices in relation to their actual hemodynamic performances and improve current criteria for their selection.

Echocardiographic estimation of right ventricular wall tension: haemodynamic comparison and long-term follow-up.

Prognosis in pulmonary hypertension is strictly linked to right ventricle failure, which results from uncoupling between right ventricle function and its afterload. This study sought to describe how to estimate with echocardiography right ventricular wall tension, its correlation with right ventricle haemodynamics and its prognostic role. A total of 190 patients without overt right ventricle failure but with suspected pulmonary hypertension on a previous echocardiogram underwent right heart catheterization and nearly-simultaneous echocardiography. Right ventricular wall tension was estimated according to Laplace’s law as right ventricle length × tricuspid regurgitation peak gradient and it was correlated with right ventricle haemodynamic profile; its potential prognostic impact was tested along with canonical right ventricle function parameters. Right ventricular wall tension correlated significantly with invasive estimation of right ventricle end-diastolic pressure (R: 0.343, p < 0.001) and with several other haemodynamic variables, such as mean pulmonary artery pressure, pulmonary artery compliance, transpulmonary gradient, pulmonary vascular resistance, right atrial pressure and right ventricle stroke work index (all p < 0.001). At a mean follow-up of five years and three months, only right ventricular wall tension was associated to all-cause mortality (p = 0.036), while tricuspid annular plane systolic excursion (p = 0.536), right ventricle fractional area change (p = 0.383), right ventricle fractional area change (p = 0.076), tricuspid regurgitation peak gradient (p = 0.107) and tricuspid annular plane systolic excursion/tricuspid regurgitation peak gradient (p = 0.181) could not. We identified a novel bedside echocardiographic predictor of altered right ventricle haemodynamics, which is precociously altered in patients without overt right ventricle failure and is associated to all-cause mortality at a long-term follow-up. Further studies are needed to confirm its role in pulmonary hypertension patients.

P4355Echocardiographic estimation of right ventricle wall tension: hemodynamic comparison and long term follow up

Abstract Introduction Prognosis in pulmonary hypertension (PH) is strictly linked to right ventricle (RV) failure, which results from uncoupling between RV and the superimposed pressure load; in first phases, coupling between these two actors still be preserved, at the price of augmented right ventricle wall tension (RVWT). Purpose We sought to describe how to estimate RVWT with echocardiography, how it correlates with RV hemodynamics and if it may predict prognosis. Methods A total of 190 patients without overt RV failure, with suspected pulmonary hypertension (PH) to a previous echocardiography, underwent to right heart catheterization (RHC) and nearly-simultaneous echocardiography. We estimated RVWT according to Laplace law (RV length × tricuspid regurgitation peak gradient [TRPG]), in order to predict initial RV stress, and was correlated with RV hemodynamic profile; its potential prognostic impact was tested along with canonical RV function parameters. Results In patients enrolled in our study, RVWT correlated significantly with invasive estimation of right ventricle end diastolic pressure (R 0.343, p&lt;0.001); a significant relationship between RVWT and several hemodynamic variables was observed (mean pulmonary artery pressure, pulmonary artery compliance, transpulmonary gradient, pulmonary vascular resistance, RV telediastolic pressure, right atrial pressure, RV stroke work index; all p&lt;0.001). At a mean follow up of five years and three months, only RVWT predicted all-cause mortality (p 0.036), while TAPSE, TAPSE/TRPG, RV fractional area change and RV S' wave did not. Correlation: RWVT and RV hemodynamic Hemodynamic variable R R2 p value Mean pulmonary artery pressure 0.742 0.550 &lt;0.001 RV differential pressure 0.794 0.630 &lt;0.001 Pulmonary artery pulsatory pressure 0.740 0.547 &lt;0.001 Mean right atrium pressure 0.326 0.106 &lt;0.001 Cardiac index/right atrial pressure 0.209 0.044 0.012 RV stroke work index 0.588 0.346 &lt;0.001 Pulmonary artery compliance 0.449 0.202 &lt;0.001 Pulmonary vascular resistance 0.531 0.282 &lt;0.001 Prognosis: different RV variables Discussion We identified a novel bedside echocardiographic predictor of altered RV hemodynamic, which results precociously altered in patients without overt RV failure, and able to predict all cause mortality at a long term follow up. Further studies are needed to confirm its role in PH patients.

Comparison of hemodynamics in post-operation coarctation of aorta patients with different aortic arch geometry

Comparison of hemodynamics in post-operation coarctation of aorta patients with different aortic arch geometry

An immersed interface method for discrete surfaces

Fluid-structure systems occur in a range of scientific and engineering applications. The immersed boundary (IB) method is a widely recognized and effective modeling paradigm for simulating fluid-structure interaction (FSI) in such systems, but a difficulty of the IB formulation of these problems is that the pressure and viscous stress are generally discontinuous at fluid-structure interfaces. The conventional IB method regularizes these discontinuities, which typically yields low-order accuracy at these interfaces. The immersed interface method (IIM) is an IB-like approach to FSI that sharply imposes stress jump conditions, enabling higher-order accuracy, but prior applications of the IIM have been largely restricted to numerical methods that rely on smooth representations of the interface geometry. This paper introduces an immersed interface formulation that uses only a C0 representation of the immersed interface, such as those provided by standard nodal Lagrangian finite element methods. Verification examples for models with prescribed interface motion demonstrate that the method sharply resolves stress discontinuities along immersed boundaries while avoiding the need for analytic information about the interface geometry. Our results also demonstrate that only the lowest-order jump conditions for the pressure and velocity gradient are required to realize global second-order accuracy. Specifically, we demonstrate second-order global convergence rates along with nearly second-order local convergence in the Eulerian velocity field, and between first- and second-order global convergence rates along with approximately first-order local convergence for the Eulerian pressure field. We also demonstrate approximately second-order local convergence in the interfacial displacement and velocity along with first-order local convergence in the fluid traction along the interface. As a demonstration of the method's ability to tackle more complex geometries, the present approach is also used to simulate flow in a patient-averaged anatomical model of the inferior vena cava, which is the large vein that carries deoxygenated blood from the lower and middle body back to the heart. Comparisons of the general hemodynamics and wall shear stress obtained by the present IIM and a body-fitted discretization approach show that the present method yields results that are in good agreement with those obtained by the body-fitted approach.

Haemodynamic Comparison between Isobaric Bupivacaine Fentanyl and Isobaric Ropivacaine Fentanyl for Lower Abdomoinaland Lower Limb Surgery

Haemodynamic Comparison between Isobaric Bupivacaine Fentanyl and Isobaric Ropivacaine Fentanyl for Lower Abdomoinaland Lower Limb Surgery

Efficacy of LVIS vs. Enterprise Stent for Endovascular Treatment of Medium-Sized Intracranial Aneurysms: A Hemodynamic Comparison Study

Background: We conducted a computational fluid dynamics (CFD) study and compared the treatment of medium-sized intracranial aneurysms with LVIS and Enterprise stent-assisted coil embolization (SACE) to determine the effects of hemodynamic changes caused by different stent and coil packing densities (PDs) in endovascular treatment.Methods: We enrolled 87 consecutive patients, with 87 medium-sized intracranial aneurysms (≥7, ≤ 12 mm), who underwent LVIS or Enterprise SACE. Aneurysms treated with LVIS SACE were allocated to the LVIS group, and the remainder were allocated to the Enterprise group. CFD were performed to assess hemodynamic alterations between before treatment, after stent deployment, and after SACE.Results: One aneurysm recanalized in the LVIS group (n = 42), and five recanalized in the Enterprise group (n = 45) (recanalization rate: 2.4 vs. 11.1%, respectively; P = 0.108). Higher complete obliteration rate (P = 0.069) was found in the LVIS group. Velocity at the neck plane showed a greater reduction ratio than velocity and WSS of the aneurysm in both groups after stent deployment, while velocity and WSS of the aneurysm showed a greater reduction ratio after coil placement. Further, there was a greater reduction in velocity at the neck plane (59.52 vs. 39.81%), aneurysmal velocity (88.46 vs. 69.45%), and wall shear stress (WSS) (85.45 vs. 69.49%) on the aneurysm in the LVIS group (P < 0.001 for all). Specifically, the reduction ratio of velocity at the neck plane showed significant difference between the groups in the multivariate analysis (P = 0.013).Conclusions : LVIS SACE showed a lower recanalization for endovascular treatment of medium-sized intracranial aneurysms, and the greater hemodynamic alterations might be the key factors.

Comparison of Exercise Hemodynamics in Patients Supported with Centrifugal and Axial Flow Left Ventricular Assist Devices

Comparison of Exercise Hemodynamics in Patients Supported with Centrifugal and Axial Flow Left Ventricular Assist Devices

A Comparison of Middle Cerebral Artery and Central Retinal Artery Hemodynamics in HM II Patients

Purpose In the normal, pulsatile circulation, the hemodynamic pattern of the middle cerebral artery (MCA) differs from the central retinal artery (CRA). Whether continuous flow from a left ventricular assist device (LVAD) alters this relationship is not known. Since serious adverse events in different end-organs, such as stroke and GI bleeding, are frequent in LVAD patients, comparing hemodynamics in different arterial beds may enhance our understanding of the specific pathophysiology of these complications. Hypothesis Because of continuous flow, hemodynamic patterns between the MCA and CRA are more similar in HeartMate II (HM II) patients compared with healthy individuals. Methods MCA and CRA time-averaged maximal flow velocity (TAMAX), pulsatility index (PI) and resistance index (RI) were determined using Doppler ultrasound with angle correction, in 20 HM II pts and 21 healthy individuals. To test the study hypothesis, data were statistically analysed for both group differences and group variances. Results Although PI and RI were markedly lower in HM II patients in both the MCA and CRA (P Conclusion The typical differences that are observed in small- and microcirculatory hemodynamics of healthy individuals are altered in HM II patients. Notably, the wide ranges of haemodynamics observed in the HM II group may carry important implications with respect to the pathophysiology of specific end-organ complications, and, eventually, the identification of high-risk patients.

General Anaesthesia versus Spinal Anaesthesia for Laparoscopic Cholecystectomy: Which Is Better Choice

Background: There is a growing evidence to suggest that regional anesthesia has an important role to play in the management of patients undergoing laparoscopic procedures. Subjects and Methods: We compared spinal anesthesia with general anesthesia, for laparoscopic cholecystectomy in 100 ASA grade 1 and 2 patients between the age of 18-50 years, divided equally into two groups given either GA or SA. The groups were compared by hemodynamic variables, intra operative events, post operative pain, operative conditions for surgeon and complications if any. Statistical Analysis: Data summarised as Mean ± SE. Groups were compared by Student’s t test , (ANOVA), Newman-Keuls post hoc test and chi-square (χ2) test. Results: Hemodynamic comparison showed better hemodynamic profile in group SA than group GA. The time of rescue analgesia was comparatively higher in SA than GA. The no. of diclofenac used lower comparatively in SA than GA. Comparing the intra operative events of two groups there was higher shoulder pain in SA as compared to GA. However, hypotension was found similar between the two groups. Post operative side effects showed higher pruritis and urinary retention whereas lower sore throat in SA as compared to GA. However PONV and headache were found similar between the two groups. There was higher surgeon and patient satisfaction in GA as compared to SA. Conclusion: We concluded that laparoscopic cholecystectomy can be conducted safely under Spinal anaesthesia with excellent recovery and high degree of satisfaction in selected patients.

A Comparison of Emergence Characteristics, Intraoperative Haemodynamics and Intraoperative Brain Relaxation between Isoflurane and Desflurane in Patients Undergoing Craniotomy for Supratentorial Lesions.

Background: Desflurane had increased anaesthetic armamentarium for maintenance of general anesthesia in neurosurgical cases. Few studies have compared isoflurane and desflurane for patients undergoing elective supratentorial craniotomy. Aims: The aim of this study is to compare emergence characteristics, intraoperative haemodynamic and intraoperative brain relaxation between isoflurane and desflurane in patients undergoing craniotomy for supratentorial lesions. Settings and Design: Prospective randomized and comparative study. Subjects and Methods: In this study, patients were randomly allocated in two groups. Groups I and D received Isoflurane and desflurane in MAC (0.8-1.2) during maintenance of general anesthesia after endotracheal intubation till skin closure. Emergence time, Extubation time, perioperative hypertension and intraoperative brain relaxation was compared between 2 groups across different time period. Statistical Analysis: Mean and standard deviation were calculated. Test of analysis between two groups was done by t-test and then P value was calculated. Results: Significantly lesser emergence time and extubation time in group D compared to group I (7.53±2.11 vs 15.10±1.7 and 10.87±1.961 vs 18.20±1.92). Perioperative haemodynamics were among comparable between both groups. Intraoperative brain relaxation was also comparable between 2 groups with more patients in desflurane group having grade 1 relaxation. Incidence of emergence hypertension and post-operative complication were also similar with 2 groups. Conclusion: It is concluded from the study that both inhalational agents isoflurane and desflurane can be used in patients undergoing supratentorial surgeries, desflurane has added advantage of faster post-operative recovery and intraoperative brain relaxation and emergence characteristics.

Comparison of Biomechanical Properties and Hemodynamics of Three Different Vena Cava Filters

The interaction mechanism of three types of vena cava filters (VCFs) with blood vessels and their influence on the bloodstream during the process of implantation are investigated by finite element method and computational fluid dynamics. The VCF models are set up with Solidworks software. Using ABAQUS software, we simulate the working conditions of the VCFs in the vessel to analyze the stress distribution and radial support stiffness of the vessel wall and the filter surface. Using FLUENT software, we simulate and analyze the velocity, pressure and shear stress distributions of blood flow when the VCFs are at their working conditions. For the retrievable VCF (R-VCF), the peak stress at the working conditions of the VCF is the highest, the peak stress toward the vessel wall is the lowest, and the support stiffness is the lowest. For the permanent VCF (P-VCF), the peak stress at the working conditions of the VCF is the highest, the peak stress toward the vessel wall is the lowest, and the support stiffness is the highest. Because of the structure of scaffolding support units and the tendency to form intimal hyperplasia on their support units, both the convertible VCF (C-VCF) and the P-VCF can embed their support units in the hyperplasia skin. This effectively prevents them from harming blood veins through filter damage at the pulse load conditions. As the biomechanical property of the C-VCF is between those of the R-VCF and the P-VCF, it has smaller obstacle to blood flow after conversion and has some fragmentation effects on the thrombus. The results show that different types of VCFs differ in their biomechanical and hemodynamic properties after implantation. Therefore, the simulative analysis can provide a reference basis for filter design and clinical decision making.

Impact of Flow Differentials According to Cardiac and Respiratory Cycles on Three Types of Fontan Operation.

Few hemodynamic comparison studies on various types of Fontan operation have been reported. The objective of this study was to perform hemodynamic comparisons for flow size and volume in three types of Fontan operation: atriopulmonary connection (APC), lateral tunnel (LT), and extracardiac conduit (ECC). Forty patients with Fontan operation (8 with APC Fontan, 22 with LT Fontan, and 10 with ECC Fontan) were enrolled. Velocity time integral (VTI) and average peak velocity (APV) were assessed according to cardiac and respiratory cycles in SVC, IVC, hepatic vein, conduit, LPA, and RPA using direct intravenous Doppler echocardiography. During each cardiac cycle in APC, VTI and APV between inspiration and expiration did not show significant differences in SVC, IVC, HV, LPA, or RPA. During each cardiac cycle in LT and ECC, VTI and APV between inspiration and expiration showed significant differences in all native vessels. The gap between S and D wave in APC was the highest, followed by that in LT. It was the lowest in ECC regardless of inspiration or expiration. Hepatic reverse VTI and APV in APC showed significant decreases compared to those in VC and PA during inspiration and expiration. Flow size and volume in APC were more influenced by cardiac cycle. Those in LT were moderately influenced by both respiratory cycle and cardiac cycle while those in ECC were more influenced by respiratory cycle. APC Fontan has hemodynamic inefficiency with prominent reverse flow. However, total cavopulmonary connection (TCPC) Fontan has more hemodynamic efficiency without prominent reverse flows.

Novel Minimally Invasive Surgical Approach for Refractory Cardiogenic Shock: A Hemodynamic Comparison With Current Percutaneous Strategies

Percutaneous mechanical circulatory (p-MCS) support devices are increasingly used in refractory cardiogenic shock (RCS), but are often limited by insufficient ventricular unloading. We developed a novel minimally invasive surgical approach (KVAD) using an external ventricular assist device with extracorporeal membrane oxygenation (ECMO) for patients in RCS. This study compares initial hemodynamic changes with this approach with contemporary p-MCS.

Racial differences in patients referred for right heart catheterization and risk of pulmonary hypertension.

African Americans (AA) have a higher incidence of pulmonary hypertension (PH) risk factors. Few studies have examined the racial differences in the prevalence and etiology of PH and direct comparison of invasive hemodynamics between AAs and Caucasians has rarely been reported. In this study, we examined whether racial differences exist in patients referred for right heart catheterization (RHC) and hypothesized that AA race is an independent risk factor for PH and is associated with increased adjusted mortality. We extracted data for AA and Caucasian patients who underwent RHC at Vanderbilt between 1998 and 2014. Clinical information was obtained from Vanderbilt's Synthetic Derivative, a de-identified mirror of our Electronic Medical Record. A total of 4576 patients were analyzed, including 586 (13%) AAs and 3990 (87%) Caucasians. AAs were younger than Caucasians by an average of eight years, but had more prevalent heart failure, features of metabolic syndrome, and higher creatinine. AAs also had higher mean pulmonary artery pressure and pulmonary vascular resistance. After adjusting for relevant co-morbidities, the AA race is associated with 41% increased risk of PH (odds ratio [OR] = 1.41, 95% confidence interval [CI] = 1.12–1.79). Among patients with PH, AA race is associated with 24% increased adjusted mortality (hazard ratio [HR] = 1.24, 95% CI = 1.09–1.45). AAs were younger but had more prevalent cardiometabolic and renal disease and worse pulmonary hemodynamics. The AA race is an independent risk factor for PH. Among patients with PH, the AA race is associated with increased adjusted mortality. Future studies should focus on delineating whether genetic or environmental factors contribute to PH risk in AAs.

Artificial stenoses for computational hemodynamics

Atherosclerosis is a major cause of death in developed countries. Mass accumulation in artery walls causes obstruction to the blood flow, stenoses, giving origin to life threatening events. This work focuses on the use of a simple and effective methodology for creating three-dimensional irregular stenosis in artery models for numerical and in vitro hemodynamic studies. The method infers the artery location prone to stenoses appearance by identifying areas of low wall shear stress. Then, by using a diffusional process, irregular shaped stenoses are artificially created. This simple diffusional process mimics aspects of the growth of stenoses, such as the growth rate dependence of a time dependent flux. The method was demonstrated using different artery models, one of them being taken from a healthy patient CT scan. The generated stenoses are irregularly shaped and are highly dependent on the flow patterns developed in each artery type. The method disclosed allows a fast hemodynamic comparison between healthy and a stenotic case for a given artery geometry.