Diffuse optical measurements of head and neck tumor hemodynamics for early prediction of radiation therapy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Dong, Lixin; Kudrimoti, Mahesh; Irwin, Daniel; Chen, Li; Shang, Yu; Li, Xingzhe; Stevens, Scott D.; Shelton, Brent J.; Yu, Guoqiang

2016-03-01

Radiation therapy is a principal modality for head and neck cancers and its efficacy depends on tumor hemodynamics. Our laboratory developed a hybrid diffuse optical instrument allowing for simultaneous measurements of tumor blood flow and oxygenation. In this study, the clinically involved cervical lymph node was monitored by the hybrid instrument once a week over the treatment period of seven weeks. Based on treatment outcomes within one year, patients were classified into a complete response group (CR) and an incomplete response group (IR) with remote metastasis and/or local recurrence. A linear mixed models was used to compare tumor hemodynamic responses to the treatment between the two groups. Interestingly, we found that human papilloma virus (HPV-16) status largely affected tumor hemodynamic responses. For HPV-16 negative tumors, significant differences in blood flow index (BFI, p = 0.007) and reduced scattering coefficient (μs', p = 0.0005) were observed between the two groups; IR tumors exhibited higher μs' values and a continuous increase in BFI over the treatment period. For HPV-16 positive tumors, oxygenated hemoglobin concentration ([HbO2]) and blood oxygen saturation (StO2) were significant different (p = 0.003 and 0.01, respectively); IR group showed lower [HbO2] and StO2. Our results imply HPV-16 negative tumors with higher density of vasculature (μs') and higher blood flow show poor responses to radiotherapy and HPV-16 positive tumors with lower tissue oxygenation level (lower StO2 and [HbO2]) exhibit poor treatment outcomes. Our diffuse optical measurements show the great potential for early prediction of radiotherapy in head and neck cancers.

Optimal control of CPR procedure using hemodynamic circulation model

DOEpatents

Lenhart, Suzanne M.; Protopopescu, Vladimir A.; Jung, Eunok

2007-12-25

A method for determining a chest pressure profile for cardiopulmonary resuscitation (CPR) includes the steps of representing a hemodynamic circulation model based on a plurality of difference equations for a patient, applying an optimal control (OC) algorithm to the circulation model, and determining a chest pressure profile. The chest pressure profile defines a timing pattern of externally applied pressure to a chest of the patient to maximize blood flow through the patient. A CPR device includes a chest compressor, a controller communicably connected to the chest compressor, and a computer communicably connected to the controller. The computer determines the chest pressure profile by applying an OC algorithm to a hemodynamic circulation model based on the plurality of difference equations.

Hemodynamic alterations in chronically conscious unrestrained diabetic rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbonell, L.F.; Salmon, M.G.; Garcia-Estan, J.

1987-05-01

Important cardiovascular dysfunctions have been described in streptozotocin (STZ)-diabetic rats. To determine the influence of these changes on the hemodynamic state and whether insulin treatment can avoid them, different hemodynamic parameters, obtained by the thermodilution method, were studied in STZ-induced (65 mg/kg) diabetic male Wistar rats, as well as in age-control, weight-control, and insulin-treated diabetic ones. Plasma volume was measured by dilution of radioiodinated (/sup 125/I) human serum albumin. All rats were examined in the conscious, unrestrained state 12 wk after induction of diabetes or acidified saline (pH 4.5) injection. At 12 wk of diabetic state most important findings weremore » normotension, high blood volume, bradycardia, increase in stroke volume, cardiac output, and cardiosomatic ratio, and decrease in total peripheral resistance and cardiac contractility and relaxation (dP/dt/sub max/ and dP/dt/sub min/ of left ventricular pressure curves). The insulin-treated diabetic rats did not show any hemodynamic differences when compared with the control animals. These results suggest that important hemodynamic alterations are present in the chronic diabetic states, possibly conditioning congestive heart failure. These alterations can be prevented by insulin treatment.« less

Some changes of the heart bioelectric activity at the cosmonauts under the influence of LBNP in the long duration flights.

PubMed

Shelepnevich, S O; Alferova, I V; Golybchicova, Z A

2004-07-01

There was selected the group of the cosmonauts, who carry out long duration flights on the orbital complex "Mir", in which the tolerance of LBNP test was evaluated as poor (by hemodynamic indices--heart rate, arterial pressure, rheoencephalographic indices). The in-depth analysis of the electrocardiogram (in DS leads) indices was carry oiled on possible disturbances of conductivity and dynamics of temporary or amplitude characteristics. Furthermore is carry oiled the comparative estimation of these indices with the results of ECG analysis at the cosmonauts, who tolerance test good. Studies showed that the most informative ECG indices are the R, T-amplitudes and QT-interval. Under the influence of LBNP, especially during rarefactions on 45 and 50 mm Hg was noted reduction in the R, T-amplitude and the relative extension of QT-interval. The directivity of changes in these indices are identical for the cosmonauts with good and poor tolerance of the test; however in flight manifestation of the changes is more significant for the cosmonauts with poor tolerance of LBNP test. Thus, in the formation of orthostatic stability together with the hemodynamic influences take part the bioelectric processes, which are formed in the myocardium.

Left and right ventricular hemodynamic forces in healthy volunteers and elite athletes assessed with 4D flow magnetic resonance imaging.

PubMed

Arvidsson, Per M; Töger, Johannes; Carlsson, Marcus; Steding-Ehrenborg, Katarina; Pedrizzetti, Gianni; Heiberg, Einar; Arheden, Håkan

2017-02-01

Intracardiac blood flow is driven by hemodynamic forces that are exchanged between the blood and myocardium. Previous studies have been limited to 2D measurements or investigated only left ventricular (LV) forces. Right ventricular (RV) forces and their mechanistic contribution to asymmetric redirection of flow in the RV have not been measured. We therefore aimed to quantify 3D hemodynamic forces in both ventricles in a cohort of healthy subjects, using magnetic resonance imaging 4D flow measurements. Twenty five controls, 14 elite endurance athletes, and 2 patients with LV dyssynchrony were included. 4D flow data were used as input for the Navier-Stokes equations to compute hemodynamic forces over the entire cardiac cycle. Hemodynamic forces were found in a qualitatively consistent pattern in all healthy subjects, with variations in amplitude. LV forces were mainly aligned along the apical-basal longitudinal axis, with an additional component aimed toward the aortic valve during systole. Conversely, RV forces were found in both longitudinal and short-axis planes, with a systolic force component driving a slingshot-like acceleration that explains the mechanism behind the redirection of blood flow toward the pulmonary valve. No differences were found between controls and athletes when indexing forces to ventricular volumes, indicating that cardiac force expenditures are tuned to accelerate blood similarly in small and large hearts. Patients' forces differed from controls in both timing and amplitude. Normal cardiac pumping is associated with specific force patterns for both ventricles, and deviation from these forces may be a sensitive marker of ventricular dysfunction. Reference values are provided for future studies. NEW & NOTEWORTHY Biventricular hemodynamic forces were quantified for the first time in healthy controls and elite athletes (n = 39). Hemodynamic forces constitute a slingshot-like mechanism in the right ventricle, redirecting blood flow toward the pulmonary circulation. Force patterns were similar between healthy subjects and athletes, indicating potential utility as a cardiac function biomarker. Copyright © 2017 the American Physiological Society.

The Frank Stinchfield Award. Pulmonary fat embolism in revision hip arthroplasty.

PubMed

Woo, R; Minster, G J; Fitzgerald, R H; Mason, L D; Lucas, D R; Smith, F E

1995-10-01

Unilateral cemented hip hemiarthroplasty was done on 16 dogs who subsequently had revision arthroplasty and who were divided into 1 control and 3 experimental groups: The first group had cement extraction using osteotomes; the second, using a high speed burr; the third, an ultrasonic tool. Hemodynamic and transesophageal echocardiographic monitoring were done. Postmortem pulmonary specimens were examined for differences in the quantity of fat emboli. There was a significant increase in emboli with the ultrasonic tool as compared with osteotomes and high speed burr. There was no significant difference in emboli between the osteotomes and high speed burr. Fat emboli syndrome is related to mechanical compression of the femoral canal. The ultrasonic instrument was unique in its tendency to cause large embolic showers, especially during extraction of the distal cement plug. In these young dogs, minimal hemodynamic changes and no cardiac dysrhythmias occurred, which in part may be attributed to their good health. These changes may remain subclinical for patients with good cardiorespiratory reserve, or may become life threatening for those with poor reserve. By outlining the mechanisms of fat embolism in revision total hip arthroplasty, it may be possible to decrease future morbidity, especially in patients who frequently have cardiopulmonary disease.

Hemodynamic Signal Changes Accompanying Execution and Imagery of Swallowing in Patients with Dysphagia: A Multiple Single-Case Near-Infrared Spectroscopy Study

PubMed Central

Kober, Silvia Erika; Bauernfeind, Günther; Woller, Carina; Sampl, Magdalena; Grieshofer, Peter; Neuper, Christa; Wood, Guilherme

2015-01-01

In the present multiple case study, we examined hemodynamic changes in the brain in response to motor execution (ME) and motor imagery (MI) of swallowing in dysphagia patients compared to healthy matched controls using near-infrared spectroscopy (NIRS). Two stroke patients with cerebral lesions in the right hemisphere, two stroke patients with lesions in the brainstem, and two neurologically healthy control subjects actively swallowed saliva (ME) and mentally imagined to swallow saliva (MI) in a randomized order while changes in concentration of oxygenated hemoglobin (oxy-Hb) and deoxygenated hemoglobin (deoxy-Hb) were assessed. In line with recent findings in healthy young adults, MI and ME of swallowing led to the strongest NIRS signal change in the inferior frontal gyrus in stroke patients as well as in healthy elderly. We found differences in the topographical distribution and time course of the hemodynamic response in dependence on lesion location. Dysphagia patients with lesions in the brainstem showed bilateral hemodynamic signal changes in the inferior frontal gyrus during active swallowing comparable to healthy controls. In contrast, dysphagia patients with cerebral lesions in the right hemisphere showed more unilateral activation patterns during swallowing. Furthermore, patients with cerebral lesions showed a prolonged time course of the hemodynamic response during MI and ME of swallowing compared to healthy controls and patients with brainstem lesions. Brain activation patterns associated with ME and MI of swallowing were largely comparable, especially for changes in deoxy-Hb. Hence, the present results provide new evidence regarding timing and topographical distribution of the hemodynamic response during ME and MI of swallowing in dysphagia patients and may have practical impact on future dysphagia treatment. PMID:26217298

Enhanced Critical Care Air Transport Team Training for Mitigation of Task Saturation

DTIC Science & Technology

2013-03-01

specialized members (physician, critical care nurse , and respiratory therapist) trained to handle the complex, critical nature of patients in hemodynamic ...with complex medical conditions have been poorly studied. 3.0 BACKGROUND Teams are composed of three medical personnel (a physician, a nurse , and

Evaluation of hemodynamic effects of xenon in dogs undergoing hemorrhagic shock

PubMed Central

Franceschi, Ruben C.; Malbouisson, Luiz; Yoshinaga, Eduardo; Auler, José Otavio Costa; de Figueiredo (in memoriam), Luiz Francisco Poli; Carmona, Maria José C.

2013-01-01

OBJECTIVES: The anesthetic gas xenon is reported to preserve hemodynamic stability during general anesthesia. However, the effects of the gas during shock are unclear. The objective of this study was to evaluate the effect of Xe on hemodynamic stability and tissue perfusion in a canine model of hemorrhagic shock. METHOD: Twenty-six dogs, mechanically ventilated with a fraction of inspired oxygen of 21% and anesthetized with etomidate and vecuronium, were randomized into Xenon (Xe; n = 13) or Control (C; n = 13) groups. Following hemodynamic monitoring, a pressure-driven shock was induced to reach an arterial pressure of 40 mmHg. Hemodynamic data and blood samples were collected prior to bleeding, immediately after bleeding and 5, 20 and 40 minutes following shock. The Xe group was treated with 79% Xe diluted in ambient air, inhaled for 20 minutes after shock. RESULT: The mean bleeding volume was 44 mL.kg−1 in the C group and 40 mL.kg−1 in the Xe group. Hemorrhage promoted a decrease in both the cardiac index (p<0.001) and mean arterial pressure (p<0.001). These changes were associated with an increase in lactate levels and worsening of oxygen transport variables in both groups (p<0.05). Inhalation of xenon did not cause further worsening of hemodynamics or tissue perfusion markers. CONCLUSIONS: Xenon did not alter hemodynamic stability or tissue perfusion in an experimentally controlled hemorrhagic shock model. However, further studies are necessary to validate this drug in other contexts. PMID:23525321

Constraining OCT with Knowledge of Device Design Enables High Accuracy Hemodynamic Assessment of Endovascular Implants.

PubMed

O'Brien, Caroline C; Kolandaivelu, Kumaran; Brown, Jonathan; Lopes, Augusto C; Kunio, Mie; Kolachalama, Vijaya B; Edelman, Elazer R

2016-01-01

Stacking cross-sectional intravascular images permits three-dimensional rendering of endovascular implants, yet introduces between-frame uncertainties that limit characterization of device placement and the hemodynamic microenvironment. In a porcine coronary stent model, we demonstrate enhanced OCT reconstruction with preservation of between-frame features through fusion with angiography and a priori knowledge of stent design. Strut positions were extracted from sequential OCT frames. Reconstruction with standard interpolation generated discontinuous stent structures. By computationally constraining interpolation to known stent skeletons fitted to 3D 'clouds' of OCT-Angio-derived struts, implant anatomy was resolved, accurately rendering features from implant diameter and curvature (n = 1 vessels, r2 = 0.91, 0.90, respectively) to individual strut-wall configurations (average displacement error ~15 μm). This framework facilitated hemodynamic simulation (n = 1 vessel), showing the critical importance of accurate anatomic rendering in characterizing both quantitative and basic qualitative flow patterns. Discontinuities with standard approaches systematically introduced noise and bias, poorly capturing regional flow effects. In contrast, the enhanced method preserved multi-scale (local strut to regional stent) flow interactions, demonstrating the impact of regional contexts in defining the hemodynamic consequence of local deployment errors. Fusion of planar angiography and knowledge of device design permits enhanced OCT image analysis of in situ tissue-device interactions. Given emerging interests in simulation-derived hemodynamic assessment as surrogate measures of biological risk, such fused modalities offer a new window into patient-specific implant environments.

Assessment of Image Quality of Repeated Limited Transthoracic Echocardiography After Cardiac Surgery.

PubMed

Canty, David J; Heiberg, Johan; Tan, Jen A; Yang, Yang; Royse, Alistair G; Royse, Colin F; Mobeirek, Abdulelah; Shaer, Fayez El; Albacker, Turki; Nazer, Rakan I; Fouda, Muhammed; Bakir, Bakir M; Alsaddique, Ahmed A

2017-06-01

The use of limited transthoracic echocardiography (TTE) has been restricted in patients after cardiac surgery due to reported poor image quality. The authors hypothesized that the hemodynamic state could be evaluated in a high proportion of patients at repeated intervals after cardiac surgery. Prospective observational study. Tertiary university hospital. The study comprised 51 patients aged 18 years or older presenting for cardiac surgery. Patients underwent TTE before surgery and at 3 time points after cardiac surgery. Images were assessed offline using an image quality scoring system by 2 expert observers. Hemodynamic state was assessed using the iHeartScan protocol, and the primary endpoint was the proportion of limited TTE studies in which the hemodynamic state was interpretable at each of the 3 postoperative time points. Hemodynamic state interpretability varied over time and was highest before surgery (90%) and lowest on the first postoperative day (49%) (p<0.01). This variation in interpretability over time was reflected in all 3 transthoracic windows, ranging from 43% to 80% before surgery and from 2% to 35% on the first postoperative day (p<0.01). Image quality scores were highest with the apical window, ranging from 53% to 77% across time points, and lowest with the subcostal window, ranging from 4% to 70% across time points (p< 0.01). Hemodynamic state can be determined with TTE in a high proportion of cardiac surgery patients after extubation and removal of surgical drains. Copyright © 2017 Elsevier Inc. All rights reserved.

Flow-Mediated Endothelial Mechanotransduction

PubMed Central

Davies, Peter F.

2011-01-01

Mechanical forces associated with blood flow play important roles in the acute control of vascular tone, the regulation of arterial structure and remodeling, and the localization of atherosclerotic lesions. Major regulation of the blood vessel responses occurs by the action of hemodynamic shear stresses on the endothelium. The transmission of hemodynamic forces throughout the endothelium and the mechanotransduction mechanisms that lead to biophysical, biochemical, and gene regulatory responses of endothelial cells to hemodynamic shear stresses are reviewed. PMID:7624393

Effects of active, passive and motor imagery paradigms on cerebral and peripheral hemodynamics in older volunteers: a functional TCD study.

PubMed

Salinet, Angela S M; Panerai, Ronney B; Robinson, Thompson G

2012-06-01

This study aimed to compare the response of metabolic-induced cerebral hemodynamic changes measured using transcranial Doppler (TCD) ultrasonography during passive, active and motor imagery paradigms, and associated peripheral hemodynamic responses. Continuous recordings of bilateral cerebral blood flow velocity (CBFv), blood pressure, heart rate and end-tidal CO(2) were performed in 12 right-handed subjects (aged ≥45 y) before, during and after 60 s of active, passive and mental-imagined paradigms. The results revealed no significant difference in CBFv responses between the paradigms and, furthermore, the temporal patterns of the hemodynamic responses showed some degree of similarity. Moreover, significant changes were seen in cerebral and peripheral hemodynamic responses for all paradigms. Our results suggest that active, passive and motor imagery paradigms can be used interchangeably to assess hemodynamic responses. This will enable more detailed noninvasive assessment in patients, where voluntary movement is not possible, but where abnormalities of cerebral hemodynamic control mechanisms can be anticipated. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

[Indicators of general, cerebral, and regional hemodynamics in myopic schoolchildren aged 13-15 years].

PubMed

Iastrebtseva, T A; Chuprov, A D; Plotnikova, Iu A

2002-01-01

110 schoolchildren aged 13-15 years were examined. 24 of them had pseudomyopia and 6 patients myopia of various forms. A control group consisted of 38 children. Central hemodynamics was estimated by average dynamic pressure, cerebral hemodynamics--by rheoencephalography, regional hemodynamics--by dopplerography of the internal carotid and suprapubic arteries. It was found that with myopia progression, the average dynamic pressure positively comes down with reduction of reographic waves amplitude in rheogram. The blood flow rate in internal carotid and suprapubic arteries has no substantial impact on myopia course. Predisposition to arterial hypotension is a risk factor for myopia development and progression.

Computer-controlled closed-loop drug infusion system for automated hemodynamic resuscitation in endotoxin-induced shock.

PubMed

Uemura, Kazunori; Kawada, Toru; Zheng, Can; Li, Meihua; Sugimachi, Masaru

2017-10-23

Hemodynamic resuscitation in septic shock requires aggressive fluid replacement and appropriate use of vasopressors to optimize arterial pressure (AP) and cardiac output (CO). Because responses to these drugs vary between patients and within patient over time, strict monitoring of patient condition and repetitive adjustment of drug dose are required. This task is time and labor consuming, and is associated with poor adherence to resuscitation guidelines. To overcome this issue, we developed a computer-controlled closed-loop drug infusion system for automated hemodynamic resuscitation in septic shock, and evaluated the performance of the system in a canine model of endotoxin shock. Our system monitors AP, CO and central venous pressure, and computes arterial resistance (R), stressed blood volume (V) and Frank-Starling slope of left ventricle (S). The system controls R with noradrenaline (NA), and V with Ringer's acetate solution (RiA), thereby controlling AP and CO. In 4 dogs, AP and CO were measured invasively. In another 4 dogs, AP and CO were measured less invasively using clinically acceptable modalities, aiming to make the system clinically feasible. In all 8 dogs, endotoxin shock was induced by injecting Escherichia coli lipopolysaccharide, which significantly decreased AP from 95 (91-108) to 43 (39-45) mmHg, and CO from 112 (104-142) to 62 (51-73) ml·min -1 ·kg -1 . The system was then connected to the dogs, and activated. System performance was observed over a period of 4 h. Our system immediately started infusions of NA and RiA. Within 40 min, RiA increased V to target level, and NA maintained R at target level, while S was concomitantly increased. These resulted in restoration of AP to 70 (69-71) mmHg and CO to 130 (125-138) ml·min -1 ·kg -1 . Median of absolute performance error, an index of precision of control, was small in AP [2.5 (2.1-4.5) %] and CO [2.4 (1.4-5.5) %], which were not increased even when the variables were measured less invasively. In a canine model of endotoxin shock, our system automatically improved and maintained AP and CO at their target values with small performance error. Our system is potentially an attractive clinical tool for rescuing patients with septic shock.

Biomechanical and Hemodynamic Measures of Right Ventricular Diastolic Function: Translating Tissue Biomechanics to Clinical Relevance.

PubMed

Jang, Sae; Vanderpool, Rebecca R; Avazmohammadi, Reza; Lapshin, Eugene; Bachman, Timothy N; Sacks, Michael; Simon, Marc A

2017-09-12

Right ventricular (RV) diastolic function has been associated with outcomes for patients with pulmonary hypertension; however, the relationship between biomechanics and hemodynamics in the right ventricle has not been studied. Rat models of RV pressure overload were obtained via pulmonary artery banding (PAB; control, n=7; PAB, n=5). At 3 weeks after banding, RV hemodynamics were measured using a conductance catheter. Biaxial mechanical properties of the RV free wall myocardium were obtained to extrapolate longitudinal and circumferential elastic modulus in low and high strain regions (E 1 and E 2 , respectively). Hemodynamic analysis revealed significantly increased end-diastolic elastance (E ed ) in PAB (control: 55.1 mm Hg/mL [interquartile range: 44.7-85.4 mm Hg/mL]; PAB: 146.6 mm Hg/mL [interquartile range: 105.8-155.0 mm Hg/mL]; P =0.010). Longitudinal E 1 was increased in PAB (control: 7.2 kPa [interquartile range: 6.7-18.1 kPa]; PAB: 34.2 kPa [interquartile range: 18.1-44.6 kPa]; P =0.018), whereas there were no significant changes in longitudinal E 2 or circumferential E 1 and E 2 . Last, wall stress was calculated from hemodynamic data by modeling the right ventricle as a sphere: stress=Pressure×radius2×thickness. RV pressure overload in PAB rats resulted in an increase in diastolic myocardial stiffness reflected both hemodynamically, by an increase in E ed , and biomechanically, by an increase in longitudinal E 1 . Modest increases in tissue biomechanical stiffness are associated with large increases in E ed . Hemodynamic measurements of RV diastolic function can be used to predict biomechanical changes in the myocardium. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

75 FR 52294 - Effective Date of Requirement for Premarket Approval for Four Class III Preamendments Devices

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-25

... Federal Food, Drug, and Cosmetic Act (the act), as amended by the Medical Device Amendments of 1976 (the... could lead to potentially debilitating or fatal thromboembolism. b. Excessive hemolysis--poor design of the hemodynamic characteristics of the device can lead to excess hemolysis. c. Inability to support...

Intracranial microprobe for evaluating neuro-hemodynamic coupling in unanesthetized human neocortex

PubMed Central

Keller, Corey J.; Cash, Sydney S.; Narayanan, Suresh; Wang, Chunmao; Kuzniecky, Ruben; Carlson, Chad; Devinsky, Orrin; Thesen, Thomas; Doyle, Werner; Sassaroli, Angelo; Boas, David A.; Ulbert, Istvan; Halgren, Eric

2009-01-01

Measurement of the blood-oxygen-level dependent (BOLD) response with fMRI has revolutionized cognitive neuroscience and is increasingly important in clinical care. The BOLD response reflects changes in deoxy-hemoglobin concentration, blood volume, and blood flow. These hemodynamic changes ultimately result from neuronal firing and synaptic activity, but the linkage between these domains is complex, poorly understood, and may differ across species, cortical areas, diseases, and cognitive states. We describe here a technique that can measure neural and hemodynamic changes simultaneously from cortical microdomains in waking humans. We utilize a “laminar optode,” a linear array of microelectrodes for electrophysiological measures paired with a micro-optical device for hemodynamic measurements. Optical measurements include laser Doppler to estimate cerebral blood flow as well as point spectroscopy to estimate oxy- and deoxy-hemoglobin concentrations. The microelectrode array records local field potential gradients (PG) and multi-unit activity (MUA) at 24 locations spanning the cortical depth, permitting estimation of population trans-membrane current flows (Current Source Density, CSD) and population cell firing in each cortical lamina. Comparison of the laminar CSD/MUA profile with the origins and terminations of cortical circuits allows activity in specific neuronal circuits to be inferred and then directly compared to hemodynamics. Access is obtained in epileptic patients during diagnostic evaluation for surgical therapy. Validation tests with relatively well-understood manipulations (EKG, breath-holding, cortical electrical stimulation) demonstrate the expected responses. This device can provide a new and robust means for obtaining detailed, quantitative data for defining neurovascular coupling in awake humans. PMID:19428529

Intracranial microprobe for evaluating neuro-hemodynamic coupling in unanesthetized human neocortex.

PubMed

Keller, Corey J; Cash, Sydney S; Narayanan, Suresh; Wang, Chunmao; Kuzniecky, Ruben; Carlson, Chad; Devinsky, Orrin; Thesen, Thomas; Doyle, Werner; Sassaroli, Angelo; Boas, David A; Ulbert, Istvan; Halgren, Eric

2009-05-15

Measurement of the blood-oxygen-level dependent (BOLD) response with fMRI has revolutionized cognitive neuroscience and is increasingly important in clinical care. The BOLD response reflects changes in deoxy-hemoglobin concentration, blood volume, and blood flow. These hemodynamic changes ultimately result from neuronal firing and synaptic activity, but the linkage between these domains is complex, poorly understood, and may differ across species, cortical areas, diseases, and cognitive states. We describe here a technique that can measure neural and hemodynamic changes simultaneously from cortical microdomains in waking humans. We utilize a "laminar optode," a linear array of microelectrodes for electrophysiological measures paired with a micro-optical device for hemodynamic measurements. Optical measurements include laser Doppler to estimate cerebral blood flow as well as point spectroscopy to estimate oxy- and deoxy-hemoglobin concentrations. The microelectrode array records local field potential gradients (PG) and multi-unit activity (MUA) at 24 locations spanning the cortical depth, permitting estimation of population trans-membrane current flows (Current Source Density, CSD) and population cell firing in each cortical lamina. Comparison of the laminar CSD/MUA profile with the origins and terminations of cortical circuits allows activity in specific neuronal circuits to be inferred and then directly compared to hemodynamics. Access is obtained in epileptic patients during diagnostic evaluation for surgical therapy. Validation tests with relatively well-understood manipulations (EKG, breath-holding, cortical electrical stimulation) demonstrate the expected responses. This device can provide a new and robust means for obtaining detailed, quantitative data for defining neurovascular coupling in awake humans.

[Resistivity and hemodynamic reactions of essentially healthy pilots to the passive orthostatic test].

PubMed

Bondareva, S V; Vartbaronov, R A; Ponomarenko, K V; Bagaudinov, K G; Khomenko, M N

2009-01-01

The paper analyzes the data of expert tilt testing (-80 degrees, 20 min.) of 66 essentially healthy pilots. Hemodynamic reactions were characterized based on the standard concept of functional classes (FC). Good test tolerance was recorded in 86.4% of cases among which 36.4% were referred to FC-I and 50%--to FC-II. Adequate test tolerance (FC-II) was recorded in 10.6%; reduced and poor test tolerance (FC-IV and FC-V)--in 3%. According to ECG and computerized tachooscillography, the adaptive hemodynamic reactions were optimum in pilots of group FC-I as compared with group FC-II and all the more so when compared with FC-III. The last two groups showed some objective symptoms that had not been looked for in the past (a distinct lability of blood pressure, and incomplete hypertensive and hypotensive reactions) that differentiated these groups from FC-I. Results of the analysis made it possible to put forward additional clinical functional criteria to assess tilt tolerance of pilots with different levels of functional tolerance.

Hepatic Hemangiomas Alter Morphometry and Impair Hemodynamics of the Abdominal Aorta and Primary Branches From Computer Simulations.

PubMed

Yin, Xiaoping; Huang, Xu; Li, Qiao; Li, Li; Niu, Pei; Cao, Minglu; Guo, Fei; Li, Xuechao; Tan, Wenchang; Huo, Yunlong

2018-01-01

Background: The formation of hepatic hemangiomas (HH) is associated with VEGF and IL-7 that alter conduit arteries and small arterioles. To our knowledge, there are no studies to investigate the effects of HH on the hemodynamics in conduit arteries. The aim of the study is to perform morphometric and hemodynamic analysis in abdominal conduit arteries and bifurcations of HH patients and controls. Methods: Based on morphometry reconstructed from CT images, geometrical models were meshed with prismatic elements for the near wall region and tetrahedral and hexahedral elements for the core region. Simulations were performed for computation of the non-Newtonian blood flow using the Carreau-Yasuda model, based on which multiple hemodynamic parameters were determined. Results: There was an increase of the lumen size, diameter ratio, and curvature in the abdominal arterial tree of HH patients as compared with controls. This significantly increased the surface area ratio of low time-averaged wall shear stress (i.e., SAR-TAWSS [Formula: see text] 100%) (24.1 ± 7.9 vs. 5 ± 6%, 11.6 ± 12.8 vs. < 0.1%, and 44.5 ± 9.2 vs. 21 ± 24% at hepatic bifurcations, common hepatic arteries, and abdominal aortas, respectively, between HH and control patients). Conclusions: Morphometric changes caused by HH significantly deteriorated the hemodynamic environment in abdominal conduit arteries and bifurcations, which could be an important risk factor for the incidence and progression of vascular diseases.

Natriuretic Peptide and Clinical Evaluation in the Diagnosis of Heart Failure Hemodynamic Profile: Comparison with Tissue Doppler Echocardiography.

PubMed

Almeida Junior, Gustavo Luiz Gouvêa de; Clausell, Nadine; Garcia, Marcelo Iorio; Esporcatte, Roberto; Rangel, Fernando Oswaldo Dias; Rocha, Ricardo Mourilhe; Beck-da-Silva, Luis; Silva, Fabricio Braga da; Gorgulho, Paula de Castro Carvalho; Xavier, Sergio Salles

2018-03-01

Physical examination and B-type natriuretic peptide (BNP) have been used to estimate hemodynamics and tailor therapy of acute decompensated heart failure (ADHF) patients. However, correlation between these parameters and left ventricular filling pressures is controversial. This study was designed to evaluate the diagnostic accuracy of physical examination, chest radiography (CR) and BNP in estimating left atrial pressure (LAP) as assessed by tissue Doppler echocardiogram. Patients admitted with ADHF were prospectively assessed. Diagnostic characteristics of physical signs of heart failure, CR and BNP in predicting elevation (> 15 mm Hg) of LAP, alone or combined, were calculated. Spearman test was used to analyze the correlation between non-normal distribution variables. The level of significance was 5%. Forty-three patients were included, with mean age of 69.9 ± 11.1years, left ventricular ejection fraction of 25 ± 8.0%, and BNP of 1057 ± 1024.21 pg/mL. Individually, all clinical, CR or BNP parameters had a poor performance in predicting LAP ≥ 15 mm Hg. A clinical score of congestion had the poorest performance [area under the receiver operating characteristic curve (AUC) 0.53], followed by clinical score + CR (AUC 0.60), clinical score + CR + BNP > 400 pg/mL (AUC 0.62), and clinical score + CR + BNP > 1000 pg/mL (AUC 0.66). Physical examination, CR and BNP had a poor performance in predicting a LAP ≥ 15 mm Hg. Using these parameters alone or in combination may lead to inaccurate estimation of hemodynamics.

Cerebral Hemodynamics Patterns by Transcranial Doppler in Patients With Acute Liver Failure.

PubMed

Abdo, A; Pérez-Bernal, J; Hinojosa, R; Porras, F; Castellanos, R; Gómez, F; Gutiérrez, J; Castellanos, A; Leal, G; Espinosa, N; Gómez-Bravo, M

2015-11-01

About half of patients with acute liver failure (ALF) show clinical signs of cerebral edema and intracranial hypertension. Neuroimaging diagnostics and electroencephalography have poor correlation with intracranial pressure measurement. The objective of this study was to characterize the cerebral hemodynamics patterns with transcranial Doppler (TCD) sonography in patients with ALF. We studied 21 patients diagnosed with ALF, admitted to the intensive care unit (ICU) at the Centro de Investigaciones Médico Quirúrgicas of Cuba. All of these patients had a TCD performed on arrival at ICU, evaluating the following: systolic (SV), diastolic (DV), and medium (MV) flows velocities and pulsatility index (PI) in right middle cerebral artery (RMCA) via temporal windows. The sonographic patterns of cerebral hemodynamics were as follows: low-flow, 12 patients (57.1%); high resistance, 5 patients (23.8%); and hyperemic, 4 patients (19%). Patients who died while waiting had lower MV RMCA (56.1 vs 58.1 cm/s) and higher PI (1.71 vs 1.41) than patients who could undergo transplantation (P = .800 and P = .787, respectively). In patients diagnosed with ALF admitted to the ICU the predominating cerebral hemodynamic pattern was low-flow with resistance increase. The TCD was shown to be a useful tool in the initial evaluation for prognosis and treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

Multi-channel NIRS of the primary motor cortex to discriminate hand from foot activity

NASA Astrophysics Data System (ADS)

Koenraadt, K. L. M.; Duysens, J.; Smeenk, M.; Keijsers, N. L. W.

2012-08-01

The poor spatial resolution of near-infrared spectroscopy (NIRS) makes it difficult to distinguish two closely located cortical areas from each other. Here, a combination of multi-channel NIRS and a centre of gravity (CoG) approach (widely accepted in the field of transcranial magnetic stimulation; TMS) was used to discriminate between closely located cortical areas activated during hand and foot movements. Similarly, the possibility of separating the more anteriorly represented discrete movements from rhythmic movements was studied. Thirteen healthy right-handed subjects performed rhythmic or discrete (‘task’) hand or foot (‘extremity’) tapping. Hemodynamic responses were measured using an 8-channel NIRS setup. For oxyhemoglobin (OHb) and deoxyhemoglobin (HHb), a CoG was determined for each condition using the mean hemodynamic responses and the coordinates of the channels. Significant hemodynamic responses were found for hand and foot movements. Based on the HHb responses, the NIRS-CoG of hand movements was located 0.6 cm more laterally compared to the NIRS-CoG of foot movements. For OHb responses no difference in NIRS-CoG was found for ‘extremity’ nor for ‘task’. This is the first NIRS study showing hemodynamic responses for isolated foot movements. Furthermore, HHb responses have the potential to be used in multi-channel NIRS experiments requiring differential activation of motor cortex areas linked to either hand or foot movements.

Imaging hypoxia using 3D photoacoustic spectroscopy

NASA Astrophysics Data System (ADS)

Stantz, Keith M.

2010-02-01

Purpose: The objective is to develop a multivariate in vivo hemodynamic model of tissue oxygenation (MiHMO2) based on 3D photoacoustic spectroscopy. Introduction: Low oxygen levels, or hypoxia, deprives cancer cells of oxygen and confers resistance to irradiation, some chemotherapeutic drugs, and oxygen-dependent therapies (phototherapy) leading to treatment failure and poor disease-free and overall survival. For example, clinical studies of patients with breast carcinomas, cervical cancer, and head and neck carcinomas (HNC) are more likely to suffer local reoccurrence and metastasis if their tumors are hypoxic. A novel method to non invasively measure tumor hypoxia, identify its type, and monitor its heterogeneity is devised by measuring tumor hemodynamics, MiHMO2. Material and Methods: Simulations are performed to compare tumor pO2 levels and hypoxia based on physiology - perfusion, fractional plasma volume, fractional cellular volume - and its hemoglobin status - oxygen saturation and hemoglobin concentration - based on in vivo measurements of breast, prostate, and ovarian tumors. Simulations of MiHMO2 are performed to assess the influence of scanner resolutions and different mathematic models of oxygen delivery. Results: Sensitivity of pO2 and hypoxic fraction to photoacoustic scanner resolution and dependencies on model complexity will be presented using hemodynamic parameters for different tumors. Conclusions: Photoacoustic CT spectroscopy provides a unique ability to monitor hemodynamic and cellular physiology in tissue, which can be used to longitudinally monitor tumor oxygenation and its response to anti-angiogenic therapies.

The hemodynamic changes in the human prefrontal cortex during the Flanker and Simon tasks: a fNIRS study

NASA Astrophysics Data System (ADS)

Yuan, Zhen; Lin, Xiaohong

2016-03-01

Functional near-infrared spectroscopy (fNIRS) is a low-cost, portable and noninvasive functional neuroimaging technique by measuring the change in the concentrations of oxyhemoglobin (HbO) and deoxyhemoglobin (HbR). The aim of present study is to reveal the different brain activity pattern of adult subjects during the completion of flanker and Simon tasks underlying the congruent and incongruent test conditions so as to identify the basic neural mechanism of inhibitory control in executive function. In the study, we utilized fNIRS to explore the hemodynamic changes in the prefrontal cortex and our imaging results suggested that there were notable differences for the hemodynamic responses between the flank and Simon task. A striking difference is that for the flank task, the increase in the HbO concentration during incongruent trials was larger than that during congruent trials for the channels across middle frontal cortex while for the Simon task, the hemodynamic response was stronger for the congruent condition compared to that from the incongruent one. Interestingly, the hemodynamic response exhibited similar task-related activation in the superior frontal cortex for both the congruent and incongruent conditions. Further, independent component analysis showed that different brain activation patterns were identified to accomplish different inhibitory control tasks underlying the congruent and incongruent conditions.

Acute hemodynamic effects of adaptive servo-ventilation in patients with heart failure.

PubMed

Yamada, Shiro; Sakakibara, Mamoru; Yokota, Takashi; Kamiya, Kiwamu; Asakawa, Naoya; Iwano, Hiroyuki; Yamada, Satoshi; Oba, Koji; Tsutsui, Hiroyuki

2013-01-01

Adaptive servo-ventilation (ASV) improves cardiac function in patients with heart failure (HF). We compared the hemodynamics of control and HF patients, and identified the predictors for acute effects of ASV in HF. We performed baseline echocardiographic measurements and hemodynamic measurements at baseline and after 15 min of ASV during cardiac catheterization in 11 control and 34 HF patients. Heart rate and blood pressure did not change after ASV in either the control or HF group. Stroke volume index (SVI) decreased from 49.3±7.6 to 41.3±7.6 ml/m2 in controls (P<0.0001) but did not change in the HF patients (from 34.8±11.5 to 32.8±8.9 ml/m2, P=0.148). In the univariate analysis, pulmonary capillary wedge pressure (PCWP), mitral regurgitation (MR)/left atrial (LA) area, E/A, E/e', and the sphericity index defined by the ratio between the short-axis and long-axis dimensions of the left ventricle significantly correlated with % change of SVI from baseline during ASV. PCWP and MR/LA area were independent predictors by multivariate analysis. Moreover, responders (15 of 34 HF patients; 44%) categorized by an increase in SVI showed significantly higher PCWP, MR, and sphericity index. Left ventricular structure and MR, as well as PCWP, could predict acute favorable effects on hemodynamics by ASV therapy in HF patients. 

Low-intensity extracorporeal shock wave therapy--a novel effective treatment for erectile dysfunction in severe ED patients who respond poorly to PDE5 inhibitor therapy.

PubMed

Gruenwald, Ilan; Appel, Boaz; Vardi, Yoram

2012-01-01

Low-intensity shock wave therapy (LI-ESWT) has been reported as an effective treatment in men with mild and moderate erectile dysfunction (ED). The aim of this study is to determine the efficacy of LI-ESWT in severe ED patients who were poor responders to phosphodiesterase type 5 inhibitor (PDE5i) therapy. This was an open-label single-arm prospective study on ED patients with an erection hardness score (EHS) ≤ 2 at baseline. The protocol comprised two treatment sessions per week for 3 weeks, which were repeated after a 3-week no-treatment interval. Patients were followed at 1 month (FU1), and only then an active PDE5i medication was provided for an additional month until final follow-up visit (FU2). At each treatment session, LI-ESWT was applied on the penile shaft and crus at five different anatomical sites (300 shocks, 0.09 mJ/mm(2) intensity at 120 shocks/min). Each subject underwent a full baseline assessment of erectile function using validated questionnaires and objective penile hemodynamic testing before and after LI-ESWT. Outcome measures used are changes in the International Index of Erectile Function-erectile function domain (IIEF-ED) scores, the EHS measurement, and the three parameters of penile hemodynamics and endothelial function. Twenty-nine men (mean age of 61.3) completed the study. Their mean IIEF-ED scores increased from 8.8 ± 1 (baseline) to 12.3 ± 1 at FU1 (P = 0.035). At FU2 (on active PDE5i treatment), their IIEF-ED further increased to 18.8 ± 1 (P < 0.0001), and 72.4% (P < 0.0001) reached an EHS of ≥ 3 (allowing full sexual intercourse). A significant improvement (P = 0.0001) in penile hemodynamics was detected after treatment and this improvement significantly correlated with increases in the IIEF-ED (P < 0.05). No noteworthy adverse events were reported. Penile LI-ESWT is a new modality that has the potential to treat a subgroup of severe ED patients. These preliminary data need to be reconfirmed by multicenter sham control studies in a larger group of ED patients. © 2011 International Society for Sexual Medicine.

The Value of Quality Improvement Process in the Detection and Correction of Common Errors in Echocardiographic Hemodynamic Parameters in a Busy Echocardiography Laboratory

PubMed Central

Fanari, Zaher; Choudhry, Usman I; Reddy, Vivek K; Eze-Nliam, Chete; Hammami, Sumaya; Kolm, Paul; Weintraub, William S.; Marshall, Erik S

2015-01-01

Background Accurate assessment of cardiac structures, ventricular function, and hemodynamics are essential for any echocardiographic laboratory. Quality Improvement (QI) processes described by the American Society of Echocardiography (ASE) and the Intersocietal Commission (IAC) should be instrumental in reaching this goal. Methods All patients undergoing transthoracic echocardiogram (TTE) followed by cardiac catheterization within 24 hours at Christiana Care Health System in 2011 and 2012 were identified, with 126 and 133 cases respectively. Hemodynamic parameters of diastolic function, Pulmonary Artery Systolic Pressure (PASP) on TTE correlated poorly with catheterization in 2011. An educational process was developed and implemented at quarterly QI meetings based on ASE and IAC recommendations to target frequently encountered errors and provide methods for improved performance. The hemodynamic parameters were then re-examined in 2012 post-intervention. Results Following the QI process, there was significant improvement in the correlation between invasive and echocardiographic hemodynamic measurements in both systolic and diastolic function, and PASP. This reflected in significant better correlations between echo and cath LVEF [R = 0.88, ICC=0.87 vs. R = 0.85, ICC=0.85; p <0.001], Average E/E’ and of left Ventricle End Diastolic Pressure (LVEDP) [R = 0.62vs. R = 0.09, p = 0.006] and a better correlation for PASP [R= 0.77, ICC=0.77 vs. R = 0.30, ICC=0.31; p = 0.05] in 2012 compared to 2011. Conclusion The QI process, as recommended by ASE and IAC, can allow for identification as well as rectification of quality issues in a large regional academic medical center hospital. PMID:26033297

Three-dimensional Echocardiography of Right Ventricular Function Correlates with Severity of Pediatric Pulmonary Hypertension.

PubMed

Jone, Pei-Ni; Patel, Sonali S; Cassidy, Courtney; Ivy, David Dunbar

2016-12-01

Right ventricular function and biomarkers of B-type natriuretic peptide (BNP) and N-Terminal pro-BNP (NT pro-BNP) are used to determine the severity of right ventricular failure and outcomes from pulmonary hypertension. Real-time three-dimensional echocardiography (3DE) is a novel quantitative measure of the right ventricle and decreases the geometric assumptions from conventional two-dimensional echocardiography (2DE). We correlated right ventricular functional measures using 2DE and single-beat 3DE with biomarkers and hemodynamics to determine the severity of pediatric pulmonary hypertension. We retrospectively evaluated 35 patients (mean age 12.67 ± 5.78 years) with established pulmonary hypertension who had echocardiograms and biomarkers on the same day. Ten out of 35 patients had hemodynamic evaluation within 3 days. 2DE evaluation included tricuspid annular plane systolic excursion (TAPSE), right ventricular myocardial performance index from tissue Doppler imaging (RV TDI MPI), and right ventricular fractional area change (FAC). Three-dimensional echocardiography evaluation included right ventricular ejection fraction (EF), end-systolic volume, and end-diastolic volume. The quality of the 3DE was graded as good, fair, or poor. Pearson correlation coefficients were utilized to evaluate between biomarkers and echocardiographic parameters and between hemodynamics and echocardiography. Three-dimensional echocardiography and FAC correlated significantly with BNP and NT pro-BNP. TAPSE and RV TDI MPI did not correlate significantly with biomarkers. 3D right ventricular EF correlated significantly with hemodynamics. Two-dimensional echocardiography did not correlate with hemodynamics. Single-beat 3DE is a noninvasive, feasible tool in the quantification of right ventricular function and maybe more accurate than conventional 2DE in evaluating severity of pulmonary hypertension. © 2016 Wiley Periodicals, Inc.

The effect of permissive hypotension in combined traumatic brain injury and blunt abdominal trauma: an experimental study in swines.

PubMed

Vrettos, T; Poimenidi, E; Athanasopoulos, P; Balasis, S; Karagiorgos, N; Siklis, T; Gatzounis, G; Fligkou, F

2016-01-01

Optimal hemodynamic resuscitation strategy of the trauma patient with uncontrolled hemorrhage and severe head injury in the pre-hospital setting remains a special challenge. Permissive hypotension prior to definite surgical haemostasis promotes coagulation, decreases blood loss and favors survival. However, hypotension is associated with poor outcome in severe head injury. The purpose of this experimental animal study was to assess the impact of permissive hypotension on survival, hemodynamic profile and brain oxygenation parameters before and/or after definite surgical haemostasis. Six-week-old pigs (n=12) underwent general anesthesia and brain injury was produced by the fluid percussion model. Animals were instrumented to measure hemodynamic parameters and cerebral blood flow. All animals (n=12) were subjected to laparotomy and a surgical knot was placed through the abdominal aorta wall. Uncontrolled hemorrhage was simulated by pulling out the intentionally left protruding free ends of the suture (goal MAP=30 mmHg). Animals were randomly divided into two groups; group A (n=6) was subjected to aggressive fluid resuscitation (goal SAP >80 mmHg) and group B (n=6) was left hypotensive (permissive hypotension). Animals who survived one hour of hypotensive shock underwent definite surgical haemostasis and were resuscitated for one hour. We measured survival, hemodynamic and brain oxygenation parameters at different time points before and after surgical haemostasis. All animals from Group A and 50% from Group B died before surgical haemostasis. In surviving animals (Group B, 50%, p=0.033), MAP, CO, rCBF, SjO2 and AVDO2 were restored to pre-procedural levels. Permissive hypotension by delaying fluid resuscitation up to definite surgical haemostasis improves survival, hemodynamics and allows restoration of cerebral oxygenation in severe head injury.

Altering hemodynamics leads to congenital heart defects (Conference Presentation)

NASA Astrophysics Data System (ADS)

Ford, Stephanie M.; McPheeters, Matthew T.; Wang, Yves T.; Gu, Shi; Doughman, Yong Qiu; Strainic, James P.; Rollins, Andrew M.; Watanabe, Michiko; Jenkins, Michael W.

2016-03-01

The role of hemodynamics in early heart development is poorly understood. In order to successfully assess the impact of hemodynamics on development, we need to monitor and perturb blood flow, and quantify the resultant effects on morphology. Here, we have utilized cardiac optical pacing to create regurgitant flow in embryonic hearts and OCT to quantify regurgitation percentage and resultant morphology. Embryonic quail in a shell-less culture were optically paced at 3 Hz (well above the intrinsic rate or 1.33-1.67 Hz) on day 2 of development (3-4 weeks human) for 5 minutes. The pacing fatigued the heart and led to a prolonged period (> 1 hour) of increased regurgitant flow. Embryos were kept alive until day 3 (cardiac looping - 4-5 weeks human) or day 8 (4 chambered heart - 8 weeks human) to quantify resultant morphologic changes with OCT. All paced embryos imaged at day 3 displayed cardiac defects. The extent of regurgitant flow immediately after pacing was correlated with cardiac cushion size 24-hours post pacing (p-value < 0.01) with higher regurgitation leading to smaller cushions. Almost all embryos (16/18) surviving to day 8 exhibited congenital heart defects (CHDs) including 11/18 with valve defects, 5/18 with ventricular septal defects and 5/18 with hypoplastic right ventricles. Our data suggests that regurgitant flow leads to smaller cushions, which develop into abnormal valves and septa. Our model produces similar phenotypes as found in our fetal alcohol syndrome and velo-cardio-facial/DiGeorge syndrome models suggesting that hemodynamics plays a role in these syndromes as well. Utilizing OCT and optical pacing to understand hemodynamics in development is an important step towards determining CHD mechanisms and ultimately developing earlier treatments.

The Value of Quality Improvement Process in the Detection and Correction of Common Errors in Echocardiographic Hemodynamic Parameters in a Busy Echocardiography Laboratory.

PubMed

Fanari, Zaher; Choudhry, Usman I; Reddy, Vivek K; Eze-Nliam, Chete; Hammami, Sumaya; Kolm, Paul; Weintraub, William S; Marshall, Erik S

2015-12-01

Accurate assessment of cardiac structures, ventricular function, and hemodynamics is essential for any echocardiographic laboratory. Quality improvement (QI) processes described by the American Society of Echocardiography (ASE) and the Intersocietal Commission (IAC) should be instrumental in reaching this goal. All patients undergoing transthoracic echocardiogram (TTE) followed by cardiac catheterization within 24 hours at Christiana Care Health System in 2011 and 2012 were identified, with 126 and 133 cases, respectively. Hemodynamic parameters of diastolic function and pulmonary artery systolic pressure (PASP) on TTE correlated poorly with catheterization in 2011. An educational process was developed and implemented at quarterly QI meetings based on ASE and IAC recommendations to target frequently encountered errors and provide methods for improved performance. The hemodynamic parameters were then reexamined in 2012 postintervention. Following the QI process, there was significant improvement in the correlation between invasive and echocardiographic hemodynamic measurements in both systolic and diastolic function, and PASP. This reflected in significant better correlations between echo and cath LVEF [R = 0.88, ICC = 0.87 vs. R = 0.85, ICC = 0.85; P < 0.001], average E/E' and of left ventricle end-diastolic pressure (LVEDP) [R = 0.62 vs. R = 0.09, P = 0.006] and a better correlation for PASP [R = 0.77, ICC = 0.77 vs. R = 0.30, ICC = 0.31; P = 0.05] in 2012 compared to 2011. The QI process, as recommended by ASE and IAC, can allow for identification as well as rectification of quality issues in a large regional academic medical center hospital. © 2015, Wiley Periodicals, Inc.

Direct Bypass Versus Indirect Bypass in Adult Moyamoya Angiopathy with Symptoms or Hemodynamic Instability: A Meta-analysis of Comparative Studies.

PubMed

Kim, Hoon; Jang, Dong-Kyu; Han, Young-Min; Sung, Jae Hoon; Park, Ik Seong; Lee, Kwan-Sung; Yang, Ji-Ho; Huh, Pil Woo; Park, Young Sup; Kim, Dal-Soo; Han, Kyung-Do

2016-10-01

It remains controversial which bypass methods are optimal for treating adult moyamoya angiopathy patients. This study aimed to analyze the literature about whether different bypass methods affect differently outcome results of adult moyamoya patients with symptoms or hemodynamic instability. A systematic search of the PubMed, Embase, and Cochrane Central databases was performed for articles published between 1990 and 2015. Comparative studies about the effect of direct or combined bypass (direct bypass group) and indirect bypass (indirect bypass group) in patients with moyamoya angiopathy at 18 years of age or older were selected. For stroke incidence at the end of the follow-up period, the degree of angiographic revascularization, hemodynamic improvement, and perioperative complication rates within 30 days, pooled relative risks were calculated between the 2 groups with a 95% confidence interval. A total of 8 articles (including 536 patients and 732 treated hemispheres) were included in the meta-analysis. There were no significant differences between the 2 groups when we compared the overall stroke rate, the hemodynamic improvement rate, or the perioperative complication rate at the end of the follow-up period. The direct bypass group, however, had a lower risk than the indirect bypass group for obtaining a poor angiographic revascularization rate (risk ratio, 0.35; 95% confidence interval, 0.15-0.84; P = 0.02). The current meta-analysis suggests that the direct or combined bypass surgical method is better for angiographic revascularization in adult moyamoya patients with symptoms or hemodynamic instability. Future studies may be necessary to confirm these findings. Copyright © 2016 Elsevier Inc. All rights reserved.

Role and Effectiveness of Percutaneous Arterial Embolization in Hemodynamically Unstable Patients with Ruptured Splanchnic Artery Pseudoaneurysms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dohan, Anthony, E-mail: anthony.dohan@lrb.aphp.fr; Eveno, Clarisse, E-mail: clarisse.eveno@lrb.aphp.fr; Dautry, Raphael, E-mail: raphael.dautry@lrb.aphp.fr

PurposeTo assess the role and effectiveness of percutaneous arterial embolization (TAE) in patients with hemodynamic instability due to hypovolemic shock secondary to ruptured splanchnic artery pseudoaneurysms (SAPA).Materials and MethodsSeventeen patients (11 men, 6 women; mean age, 53 years) with hemodynamic instability (systolic blood pressure <90 mmHg) due to hypovolemic shock secondary to ruptured SAPA were treated by TAE. Clinical files, multidetector row computed tomography angiography, and angiographic examinations along with procedure details were reviewed.ResultsSeventeen SAPAs were present, predominantly located on gastroduodenal or pancreatic arteries (9/17; 53 %). Angiography showed extravasation of contrast medium from SAPA in 15/17 patients (88 %). Technical success rate ofmore » TAE was 100 %. TAE was performed using metallic coils in all patients (100 %), in association with gelatin sponge in 5/17 patients (29 %). TAE allowed controlling the bleeding and returning to normal hemodynamic status in 16/17 patients (94 %). In 1/17 patient (6 %), surgery was needed to definitively control the bleeding. The mortality and morbidity rate of TAE at 30 days were 0 and 12 %, respectively. Morbidity consisted in coil migration in 1/17 patient (6 %) and transient serum liver enzyme elevation in 1/17 patient (6 %).ConclusionTAE is an effective and safe treatment option for ruptured SAPA in hemodynamically unstable patients, with a success rate of 94 %. Our results suggest that TAE should be the favored option in patients with hemodynamic instability due to ruptured SAPA.« less

Assessment of hemodynamics in a rat model of liver cirrhosis with precancerous lesions using multislice spiral CT perfusion imaging.

PubMed

Ma, Guolin; Bai, Rongjie; Jiang, Huijie; Hao, Xuejia; Ling, Zaisheng; Li, Kefeng

2013-01-01

To develop an optimal scanning protocol for multislice spiral CT perfusion (CTP) imaging to evaluate hemodynamic changes in liver cirrhosis with diethylnitrosamine- (DEN-) induced precancerous lesions. Male Wistar rats were randomly divided into the control group (n = 80) and the precancerous liver cirrhosis group (n = 40). The control group received saline injection and the liver cirrhosis group received 50 mg/kg DEN i.p. twice a week for 12 weeks. All animals underwent plain CT scanning, CTP, and contrast-enhanced CT scanning. Scanning parameters were optimized by adjusting the diatrizoate concentration, the flow rate, and the delivery time. The hemodynamics of both groups was further compared using optimized multislice spiral CTP imaging. High-quality CTP images were obtained with following parameters: 150 kV; 150 mAs; 5 mm thickness, 5 mm interval; pitch, 1; matrix, 512 × 512; and FOV, 9.6 cm. Compared to the control group, the liver cirrhosis group had a significantly increased value of the hepatic arterial fraction and the hepatic artery perfusion (P < 0.05) but significantly decreased hepatic portal perfusion and mean transit time (P < 0.05). Multislice spiral CTP imaging can be used to evaluate the hemodynamic changes in the rat model of liver cirrhosis with precancerous lesions.

The Utility of a Wireless Implantable Hemodynamic Monitoring System in Patients Requiring Mechanical Circulatory Support.

PubMed

Feldman, David S; Moazami, Nader; Adamson, Philip B; Vierecke, Juliane; Raval, Nir; Shreenivas, Satya; Cabuay, Barry M; Jimenez, Javier; Abraham, William T; O'Connell, John B; Naka, Yoshifumi

Proper timing of left ventricular assist device (LVAD) implantation in advanced heart failure patients is not well established and is an area of intense interest. In addition, optimizing LVAD performance after implantation remains difficult and represents a significant clinical need. Implantable hemodynamic monitoring systems may provide physicians with the physiologic information necessary to improve the timing of LVAD implantation as well as LVAD performance when compared with current methods. The CardioMEMS Heart sensor Allows for Monitoirng of Pressures to Improve Outcomes in NYHA Class III heart failure patients (CHAMPION) Trial enrolled 550 previously hospitalized patients with New York Heart Association (NYHA) class III heart failure. All patients were implanted with a pulmonary artery (PA) pressure monitoring system and randomized to a treatment and control groups. In the treatment group, physicians used the hemodynamic information to make heart failure management decisions. This information was not available to physicians for the control group. During an average of 18 month randomized follow-up, 27 patients required LVAD implantation. At the time of PA pressure sensor implantation, patients ultimately requiring advanced therapy had higher PA pressures, lower systemic pressure, and similar cardiac output measurements. Treatment and control patients in the LVAD subgroup had similar clinical profiles at the time of enrollment. There was a trend toward a shorter length of time to LVAD implantation in the treatment group when hemodynamic information was available. After LVAD implantation, most treatment group patients continued to provide physicians with physiologic information from the hemodynamic monitoring system. As expected PA pressures declined significantly post LVAD implant in all patients, but the magnitude of decline was higher in patients with PA pressure monitoring. Implantable hemodynamic monitoring appeared to improve the timing of LVAD implantation as well as optimize LVAD performance when compared with current methods. Further studies are necessary to evaluate these findings in a prospective manner.

Randomized trial comparing the effects of a low-dose combination of nifedipine GITS and valsartan versus high-dose monotherapy on central hemodynamics in patients with inadequately controlled hypertension: FOCUS study.

PubMed

Park, Jeong Bae; Ha, Jong-Won; Jung, Hae-Ok; Rhee, Moo-Yong

2014-10-01

Measurement of central blood pressure provides prognostic information beyond conventional peripheral blood pressure (BP). However, few studies have directly compared the effects of antihypertensives on central hemodynamics. This study investigated the effects of a low-dose combination of nifedipine Gastrointestinal Therapeutic System (GITS) and valsartan versus high-dose monotherapy with either agent in reducing central BP in essential hypertension inadequately controlled by low-dose monotherapy. In this prospective, open-label, randomized, active-controlled, multicenter 8-week study, patients not meeting the target BP after 4 weeks of treatment with low-dose monotherapy were randomized to receive nifedipine GITS 30 mg plus valsartan 80 mg (N30+V80), nifedipine GITS 60 mg (N60), or valsartan 160 mg (V160) for a further 4 weeks. Central hemodynamics were measured by applanation tonometry. A total of 391 patients were enrolled. Reduction in central systolic BP from baseline to week 8, the primary efficacy variable, was significantly greater in the N30+V80 group (-27.2±14.7 mmHg) and the N60 group (-27.1±16.5 mmHg) compared with V160 group (-14.4±16.6 mmHg). Decrease in the augmentation index in the N60 group was significantly greater compared with V160 alone, without differences between combination therapy and either high-dose monotherapy. Decreases in brachial systolic BP were significantly greater in the N30+V80 and N60 groups than in the V160 group. By multiple regression analysis, most differences in drug effects on central hemodynamics disappeared after controlling for changes in peripheral BP. A low rate of adverse events occurred in all treatment groups. A low-dose combination of nifedipine GITS plus valsartan or high-dose nifedipine was more effective in improving central hemodynamics than high-dose valsartan in patients with hypertension, mostly because of the improvement in peripheral (brachial) hemodynamics.

Development and evaluation of totally implantable ventricular assist system using a vibrating flow pump and transcutaneous energy transmission system with amorphous fibers.

PubMed

Yambe, T; Hashimoto, H; Kobayashi, S; Sonobe, T; Naganuma, S; Nanka, S S; Matsuki, H; Yoshizawa, M; Tabayashi, K; Takayasu, H; Takeda, H; Nitta, S

1997-01-01

We have developed a vibrating flow pump (VFP) that can generate oscillated blood flow with a relatively high frequency (10-50 Hz) for a totally implantable ventricular assist system (VAS). To evaluate the newly developed VAS, left heart bypasses, using the VFP, were performed in chronic animal experiments. Hemodynamic parameters were recorded in a data recorder in healthy adult goats during an awake condition and analyzed in a personal computer system through an alternating-direct current converter. Basic performance of the total system with a transcutaneous energy transmission system were satisfactory. During left ventricular assistance with the VFP, Mayer wave fluctuations of hemodynamics were decreased in the power spectrum, the fractal dimensions of the hemodynamics were significantly decreased, and peripheral vascular resistance was significantly decreased. These results suggest that cardiovascular regulatory nonlinear dynamics, which mediate the hemodynamics, may be affected by left ventricular bypass with oscillated flow. The decreased power of the Mayer wave in the spectrum caused the limit cycle attractor of the hemodynamics and decreased peripheral resistance. These results suggest that this newly developed VAS is useful for the totally implantable system with unique characteristics that can control hemodynamic properties.

Delayed systolic blood pressure recovery following exercise as a mechanism of masked uncontrolled hypertension in chronic kidney disease.

PubMed

Agarwal, Rajiv; Pappas, Maria K

2017-10-01

Among people treated for hypertension, the presence of elevated blood pressure (BP) out of the clinic but normal BP in the clinic is called masked uncontrolled hypertension (MUCH). What causes MUCH remains unknown. The purpose of this study was to answer the question of whether patients with MUCH have an increased hemodynamic reactivity to exercise and delayed hemodynamic recovery following exercise. Four groups were compared: controlled hypertension (CH, n = 58), MUCH (n = 34) and uncontrolled hypertension (UCH, n = 12), all of which had chronic kidney disease (CKD), and a group of healthy normal volunteers who did not have hypertension or CKD (n = 16). All participants underwent assessment of 24-h ambulatory BP monitoring, BP measurement during a graded symptom-limited exercise using a cycle ergometer and BP recovery over 7 min following exercise. Exercise-induced increase in systolic BP was similar among the four groups. When compared with healthy controls, recovery of systolic BP following termination of exercise was blunted among the CKD groups in unadjusted (P < 0.0001) and adjusted (P < 0.001) models. During recovery, the healthy control group had 5.9% decline in systolic BP per minute. In contrast, MUCH had only 3.3% per minute reduction and the UCH group had 0.3% reduction per minute. A test of linear trend was significant (P = 0.002, adjusted model). Because there was no impairment in the heart rate recovery among groups, we speculate that the parasympathetic pathway appears intact among treated hypertensives with CKD. However, the failure to withdraw sympathetic tone upon termination of exercise causes ongoing vasoconstriction and delayed systolic BP recovery providing a biological basis for MUCH. Delayed recovery from exercise-induced hypertension in those with poorly controlled BP provides potentially a new target to assure round-the-clock BP control. Published by Oxford University Press on behalf of ERA-EDTA 2016. This work is written by US Government employees and is in the public domain in the US.

Impact of Iodinated Contrast on Renal Function and Hemodynamics in Rats with Chronic Hyperglycemia and Chronic Kidney Disease

PubMed Central

Fernandes, Sheila Marques; Martins, Daniel Malisani; da Fonseca, Cassiane Dezoti; Watanabe, Mirian; Vattimo, Maria de Fátima Fernandes

2016-01-01

Iodinated contrast (IC) is clinically used in diagnostic and interventional procedures, but its use can result in contrast-induced acute kidney injury (CI-AKI). Chronic kidney disease (CKD) and chronic hyperglycemia (CH) are important predisposing factors to CI-AKI. The aim of this study was to investigate the impact of iodinated contrast on the renal function and hemodynamics in rats with chronic hyperglycemia and chronic kidney disease. A total of 30 rats were divided into six groups; Sham: control of chronic renal disease; Citrate: control of chronic hyperglycemia (CH); Nx5/6: rats with 5/6 nephrectomy; Chronic Hyperglycemia: rats receiving Streptozotocin 65 mg/kg; Nx5/6 + IC: rats Nx5/6 received 6 mL/kg of IC; CH + IC: Chronic hyperglycemia rats receiving 6 mL/kg of IC. Renal function (inulin clearance; urinary neutrophil gelatinase-associated lipocalin, NGAL) and hemodynamics (arterial blood pressure; renal blood flow; renal vascular resistance) were evaluated. Iodinated contrast significantly increased urinary NGAL and reduced inulin clearance, while the hemodynamics parameters showed changes in arterial blood pressure, renal blood flow, and renal vascular resistance in both CKD and CH groups. The results suggest that the iodinated contrast in risk factors models has important impact on renal function and hemodynamics. NGAL was confirmed to play a role of highlight in diagnosis of CI-AKI. PMID:27034930

Implantable hemodynamic monitoring (the Chronicle IHM system): remote telemonitoring for patients with heart failure.

PubMed

Ho, C

2008-01-01

(1) Remote monitoring for ambulatory heart failure patients uses an implantable device to record hemodynamic data and transmit it to a central server for continuous assessment. (2) Preliminary evidence from observational studies suggests a potential for reducing hospitalizations with the use of right ventricle implantable hemodynamic monitoring (IHM). However, although a multicentre, randomized controlled trial (COMPASS-HF) showed a reduction in hospitalizations in the IHM group the results were not statistically significant and the US Food and Drug Administration panel concluded the trial failed to meet its primary efficacy endpoint. (3) In the COMPASS-HF study the most common device-related complication was lead dislodgement. (4) Large randomized controlled trials are needed to demonstrate the clinical utility of IHM, particularly in terms of its impact on reducing hospitalization and improving patient outcomes.

Is MRI-based CFD able to improve clinical treatment of coarctations of aorta?

PubMed

Goubergrits, L; Riesenkampff, E; Yevtushenko, P; Schaller, J; Kertzscher, U; Berger, F; Kuehne, T

2015-01-01

Pressure drop associated with coarctation of the aorta (CoA) can be successfully treated surgically or by stent placement. However, a decreased life expectancy associated with altered aortic hemodynamics was found in long-term studies. Image-based computational fluid dynamics (CFD) is intended to support particular diagnoses, to help in choosing between treatment options, and to improve performance of treatment procedures. This study aimed to prove the ability of CFD to improve aortic hemodynamics in CoA patients. In 13 patients (6 males, 7 females; mean age 25 ± 14 years), we compared pre- and post-treatment peak systole hemodynamics [pressure drops and wall shear stress (WSS)] vs. virtual treatment as proposed by biomedical engineers. Anatomy and flow data for CFD were based on MRI and angiography. Segmentation, geometry reconstruction and virtual treatment geometry were performed using the software ZIBAmira, whereas peak systole flow conditions were simulated with the software ANSYS(®) Fluent(®). Virtual treatment significantly reduced pressure drop compared to post-treatment values by a mean of 2.8 ± 3.15 mmHg, which significantly reduced mean WSS by 3.8 Pa. Thus, CFD has the potential to improve post-treatment hemodynamics associated with poor long-term prognosis of patients with coarctation of the aorta. MRI-based CFD has a huge potential to allow the slight reduction of post-treatment pressure drop, which causes significant improvement (reduction) of the WSS at the stenosis segment.

A Review of Central Venous Pressure and Its Reliability as a Hemodynamic Monitoring Tool in Veterinary Medicine.

PubMed

Hutchinson, Kristen M; Shaw, Scott P

2016-09-01

To review the current literature regarding central venous pressure (CVP) in veterinary patients pertaining to placement (of central line), measurement, interpretation, use in veterinary medicine, limitations, and controversies in human medicine. CVP use in human medicine is a widely debated topic, as numerous sources have shown poor correlation of CVP measurements to the volume status of a patient. Owing to the ease of placement and monitoring in veterinary medicine, CVP remains a widely used modality for evaluating the hemodynamic status of a patient. A thorough evaluation of the veterinary and human literature should be performed to evaluate the role of CVP measurements in assessing volume status in veterinary patients. Veterinary patients that benefit from accurate CVP readings include those suffering from hypovolemic or septic shock, heart disease, or renal disease or all of these. Other patients that may benefit from CVP monitoring include high-risk anesthetic patients undergoing major surgery, trending of fluid volume status in critically ill patients, patients with continued shock, and patients that require rapid or large amounts of fluids. The goal of CVP use is to better understand a patient's intravascular volume status, which would allow early goal-directed therapy. CVP would most likely continue to play an important role in the hemodynamic monitoring of the critically ill veterinary patient; however, when available, cardiac output methods should be considered the first choice for hemodynamic monitoring. Copyright © 2016 Elsevier Inc. All rights reserved.

Simulation of acute haemodynamic outcomes of the surgical strategies for the right ventricular failure treatment in pediatric LVAD.

PubMed

Di Molfetta, Arianna; Ferrari, Gianfranco; Iacobelli, Roberta; Filippelli, Sergio; Fresiello, Libera; Gagliardi, Maria G; Toscano, Alessandro; Trivella, Maria G; Amodeo, Antonio

2015-12-01

Right ventricular failure (RVF) is one of the major complications during LVAD. Apart from drug therapy, the most reliable option is the implantation of RVAD. However, BIVAD have a poor prognosis and increased complications. Experiments have been conducted on alternative approaches, such as the creation of an atrial septal defect (ASD), a cavo-aortic shunt (CAS) including the LVAD and a cavo-pulmonary connection (CPC). This work aims at realizing a lumped parameter model (LPM) to compare the acute hemodynamic effects of ASD, CPC, CAS, RVAD in LVAD pediatric patients with RVF. Data of 5 pediatric patients undergoing LVAD were retrospectively collected to reproduce patients baseline hemodynamics with the LPM. The effects of continuous flow LVAD implantation complicated by RVF was simulated and then the effects of ASD, CPC, CAS and RVAD treatments were simulated for each patient. The model successfully reproduced patients' baseline and the hemodynamic effects of the surgical strategies. Simulating the different surgical strategies, an unloading of the right ventricle and an increment of left ventricular preload were observed with an improvement of the hemodynamics (total cardiac output: ASD +15%, CPC +10%, CAS +70% RVAD +20%; right ventricular external work: ASD -19%, CPC -46%, CAS -76%, RVAD -32%; left ventricular external work: ASD +12%, CPC +28%, RVAD +64%). The use of numerical model could offer an additional support for clinical decision-making, also potentially reducing animal experiments, to compare the outcome of different surgical strategies to treat RVF in LVAD.

The association between cognitive deficits and prefrontal hemodynamic responses during performance of working memory task in patients with schizophrenia.

PubMed

Pu, Shenghong; Nakagome, Kazuyuki; Itakura, Masashi; Iwata, Masaaki; Nagata, Izumi; Kaneko, Koichi

2016-04-01

Schizophrenia-associated cognitive deficits are resistant to treatment and thus pose a lifelong burden. The Brief Assessment of Cognition in Schizophrenia (BACS) provides reliable and valid assessments across cognitive domains. However, because the prefrontal functional abnormalities specifically associated with the level of cognitive deficits in schizophrenia have not been examined, we explored this relationship. Patients with schizophrenia (N=87) and matched healthy controls (N=50) participated in the study. Using near-infrared spectroscopy (NIRS), we measured the hemodynamic responses in the prefrontal and superior temporal cortical surface areas during a working memory task. Correlation analyses revealed a relationship between the hemodynamics and the BACS composite and domain scores. Hemodynamic responses of the left dorsolateral prefrontal cortex (DLPFC) and left frontopolar cortex (FPC) in the higher-level-of-cognitive-function schizophrenia group were weaker than the responses of the controls but similar to those of the lower-level-of-cognitive-function schizophrenia group. However, hemodynamic responses in the right DLPFC, bilateral ventrolateral PFC (VLPFC), and right temporal regions decreased with increasing cognitive deficits. In addition, the hemodynamic response correlated positively with the level of cognitive function (BACS composite scores) in the right DLPFC, bilateral VLPFC, right FPC, and bilateral temporal regions in schizophrenia. The correlation was driven by all BACS domains. Our results suggest that the linked functional deficits in the right DLPFC, bilateral VLPFC, right FPC, and bilateral temporal regions may be related to BACS-measured cognitive impairments in schizophrenia and show that linking the neurocognitive deficits and brain abnormalities can increase our understanding of schizophrenia pathophysiology. Copyright © 2015 Elsevier B.V. All rights reserved.

Reduced prefrontal hemodynamic response in adult attention-deficit hyperactivity disorder as measured by near-infrared spectroscopy.

PubMed

Ueda, Shotaro; Ota, Toyosaku; Iida, Junzo; Yamamuro, Kazuhiko; Yoshino, Hiroki; Kishimoto, Naoko; Kishimoto, Toshifumi

2018-06-01

Recent developments in near-infrared spectroscopy (NIRS) have enabled non-invasive clarification of brain functions in psychiatric disorders. In pediatric attention-deficit hyperactivity disorder (ADHD), reduced prefrontal hemodynamic responses have been observed with NIRS repeatedly. However, there are few studies of adult ADHD by multi-channel NIRS. Therefore, in this study, we used multi-channel NIRS to examine the characteristics of prefrontal hemodynamic responses during the Stroop Color-Word Task (SCWT) in adult ADHD patients and in age- and sex-matched control subjects. Twelve treatment-naïve adults with ADHD and 12 age- and sex-matched healthy control subjects participated in the present study after giving consent. We used 24-channel NIRS to measure the oxygenated hemoglobin (oxy-Hb) changes at the frontal lobes of participants during the SCWT. We compared the oxy-Hb changes between adults with ADHD and control subjects by t-tests with Bonferroni correction. During the SCWT, the oxy-Hb changes observed in the ADHD group were significantly smaller than those in the control group in channels 11, 16, 18, 21, 22, 23, and 24, corresponding to the prefrontal cortex. At channels 16, 21, 23, and 24 of the ADHD group, there were negative correlations between the symptomatic severity and the oxy-Hb changes. The present study suggests that adults with ADHD have reduced prefrontal hemodynamic response as measured by NIRS. © 2018 The Authors. Psychiatry and Clinical Neurosciences © 2018 Japanese Society of Psychiatry and Neurology.

[Left auricular hypertrophy in aortic stenosis in adults].

PubMed

Boschat, J; Le Mehaute, H; Le Potier, J; Roriz, R; Gilard, M; Bergez, C; Etienne, Y; Blanc, J J; Penther, P

1990-02-01

Left atrial hypertrophy (LAH) was noted from the electrocardiograms of 72 of 98 adult patients (81%) who underwent hemodynamic evaluation of calcified aortostenosis (CAS). The relations between LAH and clinical, echographic and hemodynamic findings are specified. The frequency of LAH was not higher in cases of a history of hypertension, angina pectoris, lipothymia or exercise-induced syncope. In contrast, dyspnea was more frequently associated with LAH (84%) than not (17%). An approximately linear relation was seen between LAH and the mean pulmonary capillary pressure, the mean rate of circumferential decrease (RCF), the coefficient of muscle rigidity (ks of Mirsky), the left ventricular mass (LVM) and the left ventricle-aorta gradient. LAH is, therefore, a frequent sign in patients presenting CAS. Its origin is multifactorial, with a predominance of increased mean capillary pressure in cases of clinical signs of poor safety.

Effect of Music Therapy on Patients' Anxiety and Hemodynamic Parameters During Coronary Angioplasty: A Randomized Controlled Trial.

PubMed

Forooghy, Masoumeh; Mottahedian Tabrizi, Elaheh; Hajizadeh, Ebrahim; Pishgoo, Bahram

2015-06-01

A cardiac catheterization laboratory can be a frightening environment and music can be a supportive source of environmental sound that stimulates and maintains relaxation. However, the results of studies are conflicting in this regard. The aim of this study was to investigate the effect of music therapy on patients' anxiety and hemodynamic parameters during percutaneous transluminal coronary angioplasty. This was a randomized controlled trial, conducted in the Catheterization Laboratory Unit of Baqiyatallah Hospital, in Tehran, Iran. A sample of 64 patients, who were planned to undergo coronary angioplasty, was recruited. Patients were randomly allocated to either the control or the experimental groups. In the experimental group, patients received a 20 to 40-minute music therapy intervention, consisting of light instrumental music albums by Johann Sebastian Bach and Mariko Makino. Patients in the control group received the routine care of the study setting, which consisted of no music therapy intervention. Study data were collected by a demographic questionnaire, the Spielberger's State Anxiety Inventory, and a data sheet for documenting hemodynamic parameters. Chi-square, independent-samples t tests, paired-samples t-test and repeated measures analysis of variance were used to analyze the data. Before the intervention, the study groups did not differ significantly in terms of anxiety level and hemodynamic parameters. Moreover, the differences between the two groups, regarding hemodynamic parameters, were not significant after the intervention (P > 0.05). However, the level of post-intervention anxiety in the experimental group was significantly lower than the control group (32.06 ± 8.57 and 38.97 ± 12.77, respectively; P = 0.014). Compared with the baseline readings, the level of anxiety in the control group did not change significantly after the study (41.91 ± 9.88 vs. 38.97 ± 12.77; P = 0.101); however, in the experimental group, the level of post-intervention anxiety was significantly lower than the pretest readings (32.06 ± 8.57 vs. 41.16 ± 10.6; P = 0.001). Music therapy is a safe, simple, inexpensive, and non-invasive nursing intervention, which can significantly alleviate patients' anxiety during coronary angioplasty.

Mindfulness meditation lowers muscle sympathetic nerve activity and blood pressure in African-American males with chronic kidney disease.

PubMed

Park, Jeanie; Lyles, Robert H; Bauer-Wu, Susan

2014-07-01

Mindfulness meditation (MM) is a stress-reduction technique that may have real biological effects on hemodynamics but has never previously been tested in chronic kidney disease (CKD) patients. In addition, the mechanisms underlying the potential blood pressure (BP)-lowering effects of MM are unknown. We sought to determine whether MM acutely lowers BP in CKD patients, and whether these hemodynamic changes are mediated by a reduction in sympathetic nerve activity. In 15 hypertensive African-American (AA) males with CKD, we conducted a randomized, crossover study in which participants underwent 14 min of MM or 14 min of BP education (control intervention) during two separate random-order study visits. Muscle sympathetic nerve activity (MSNA), beat-to-beat arterial BP, heart rate (HR), and respiratory rate (RR) were continuously measured at baseline and during each intervention. A subset had a third study visit to undergo controlled breathing (CB) to determine whether a reduction in RR alone was sufficient in exacting hemodynamic changes. We observed a significantly greater reduction in systolic BP, diastolic BP, mean arterial pressure, and HR, as well as a significantly greater reduction in MSNA, during MM compared with the control intervention. Participants had a significantly lower RR during MM; however, in contrast to MM, CB alone did not reduce BP, HR, or MSNA. MM acutely lowers BP and HR in AA males with hypertensive CKD, and these hemodynamic effects may be mediated by a reduction in sympathetic nerve activity. RR is significantly lower during MM, but CB alone without concomitant meditation does not acutely alter hemodynamics or sympathetic activity in CKD.

Acute effect of cycling intervention on carotid arterial hemodynamics: basketball athletes versus sedentary controls

PubMed Central

2015-01-01

Objective To compare the acute effects of a cycling intervention on carotid arterial hemodynamics between basketball athletes and sedentary controls. Methods Ten young long-term trained male basketball athletes (BA) and nine age-matched male sedentary controls (SC) successively underwent four bouts of exercise on a bicycle ergometer at the same workload. Hemodynamic variables at right common carotid artery were determined at rest and immediately following each bout of exercise. An ANCOVA was used to compare differences between the BA and SC groups at rest and immediately following the cycling intervention. The repeated ANOVA was used to assess differences between baseline and each bout of exercise within the BA or SC group. Results In both groups, carotid hemodynamic variables showed significant differences at rest and immediately after the cycling intervention. At rest, carotid arterial stiffness was significantly decreased and carotid arterial diameter was significantly increased in the BA group as compared to the SC group. Immediately following the cycling intervention, carotid arterial stiffness showed no obvious changes in the BA group but significantly increased in the SC group. It is worth noting that while arterial stiffness was lower in the BA group than in the SC group, the oscillatory shear index (OSI) was significantly higher in the BA group than in the SC group both at rest and immediately following the cycling intervention. Conclusion Long-term basketball exercise had a significant impact on common carotid arterial hemodynamic variables not only at rest but also after a cycling intervention. The role of OSI in the remodeling of arterial structure and function in the BA group at rest and after cycling requires clarification. PMID:25602805

Randomized Clinical Trial of Real-Time fMRI Amygdala Neurofeedback for Major Depressive Disorder: Effects on Symptoms and Autobiographical Memory Recall.

PubMed

Young, Kymberly D; Siegle, Greg J; Zotev, Vadim; Phillips, Raquel; Misaki, Masaya; Yuan, Han; Drevets, Wayne C; Bodurka, Jerzy

2017-08-01

Patients with depression show blunted amygdala hemodynamic activity to positive stimuli, including autobiographical memories. The authors examined the therapeutic efficacy of real-time functional MRI neurofeedback (rtfMRI-nf) training aimed at increasing the amygdala's hemodynamic response to positive memories in patients with depression. In a double-blind, placebo-controlled, randomized clinical trial, unmedicated adults with depression (N=36) were randomly assigned to receive two sessions of rtfMRI-nf either from the amygdala (N=19) or from a parietal control region not involved in emotional processing (N=17). Clinical scores and autobiographical memory performance were assessed at baseline and 1 week after the final rtfMRI-nf session. The primary outcome measure was change in score on the Montgomery-Åsberg Depression Rating Scale (MADRS), and the main analytic approach consisted of a linear mixed-model analysis. In participants in the experimental group, the hemodynamic response in the amygdala increased relative to their own baseline and to the control group. Twelve participants in the amygdala rtfMRI-nf group, compared with only two in the control group, had a >50% decrease in MADRS score. Six participants in the experimental group, compared with one in the control group, met conventional criteria for remission at study end, resulting in a number needed to treat of 4. In participants receiving amygdala rtfMRI-nf, the percent of positive specific memories recalled increased relative to baseline and to the control group. rtfMRI-nf training to increase the amygdala hemodynamic response to positive memories significantly decreased depressive symptoms and increased the percent of specific memories recalled on an autobiographical memory test. These data support a role of the amygdala in recovery from depression.

[Role of cerebral hemodynamics in the mechanism of development of acquired myopia in schoolchildren].

PubMed

Iastrebtseva, T A; Demidova, T E; Polikarpova, V E

2008-01-01

Rheoencephalography was used to study cerebral venous circulation in 199 schoolchildren aged 12-15 years who had emmetropia, pseudomyopia, and myopia. Tonometry was carried out in 39 persons. Cerebral venous hemodynamic dysfunction was more frequently encountered in schoolchildren with myopia than in those with emmetropia. Intraocular pressure was significantly higher only in schoolchildren with high myopia than in the controls.

Hemoadsorption by CytoSorb in septic patients: a case series.

PubMed

Kogelmann, Klaus; Jarczak, Dominik; Scheller, Morten; Drüner, Matthias

2017-03-27

Septic shock, defined as life-threatening organ dysfunction caused by a dysregulated host response to infection, is a highly lethal condition that causes substantial morbidity and mortality among critically ill patients. One of the hallmarks of sepsis is the excessive release of cytokines and other inflammatory mediators causing refractory hypotension, tissue damage, metabolic acidosis and ultimately multiple organ failure. In this context, cytokine reduction by hemoadsorption represents a new concept for blood purification, developed to attenuate the overwhelming systemic levels of pro-inflammatory and anti-inflammatory mediators released in the early phase of sepsis. In the present case series, we evaluated the impact of a new hemoadsorption device (CytoSorb) used as adjunctive therapy, on hemodynamics and clinically relevant outcome parameters in 26 critically ill patients with septic shock and in need of renal replacement therapy. We found that treatment of these patients with septic shock was associated with hemodynamic stabilization and a reduction in blood lactate levels. Actual mortality in the overall patient population was lower than mortality predicted by acute physiology and chronic health evaluation II (APACHE II). These effects seem to be more pronounced in patients in whom therapy started within 24 h of sepsis diagnosis, whereas a delay in the start of therapy was associated with a poor response to therapy in terms of reduction of catecholamine demand and survival. Moreover, from our patient population, medical patients seemed to benefit more than post-surgical patients in terms of survival. Treatment using the CytoSorb device was safe and well-tolerated with no device-related adverse events during or after the treatment sessions. Hemoadsorption using CytoSorb resulted in rapid hemodynamic stabilization and increased survival, particularly in patients in whom therapy was started early. Given the positive clinical experience of this case series, randomized controlled trials are urgently needed to define the potential benefits of this new treatment option.

The extended functional neuroanatomy of emotional processing biases for masked faces in major depressive disorder.

PubMed

Victor, Teresa A; Furey, Maura L; Fromm, Stephen J; Bellgowan, Patrick S F; Öhman, Arne; Drevets, Wayne C

2012-01-01

Major depressive disorder (MDD) is associated with a mood-congruent processing bias in the amygdala toward face stimuli portraying sad expressions that is evident even when such stimuli are presented below the level of conscious awareness. The extended functional anatomical network that maintains this response bias has not been established, however. To identify neural network differences in the hemodynamic response to implicitly presented facial expressions between depressed and healthy control participants. Unmedicated-depressed participants with MDD (n=22) and healthy controls (HC; n=25) underwent functional MRI as they viewed face stimuli showing sad, happy or neutral face expressions, presented using a backward masking design. The blood-oxygen-level dependent (BOLD) signal was measured to identify regions where the hemodynamic response to the emotionally valenced stimuli differed between groups. The MDD subjects showed greater BOLD responses than the controls to masked-sad versus masked-happy faces in the hippocampus, amygdala and anterior inferotemporal cortex. While viewing both masked-sad and masked-happy faces relative to masked-neutral faces, the depressed subjects showed greater hemodynamic responses than the controls in a network that included the medial and orbital prefrontal cortices and anterior temporal cortex. Depressed and healthy participants showed distinct hemodynamic responses to masked-sad and masked-happy faces in neural circuits known to support the processing of emotionally valenced stimuli and to integrate the sensory and visceromotor aspects of emotional behavior. Altered function within these networks in MDD may establish and maintain illness-associated differences in the salience of sensory/social stimuli, such that attention is biased toward negative and away from positive stimuli.

Perfusion characteristics of Moyamoya disease: an anatomically and clinically oriented analysis and comparison.

PubMed

Schubert, Gerrit Alexander; Czabanka, Marcus; Seiz, Marcel; Horn, Peter; Vajkoczy, Peter; Thomé, Claudius

2014-01-01

Moyamoya disease (MMD) is characterized by unique angiographic features of collateralization. However, a detailed quantification as well as comparative analysis with cerebrovascular atherosclerotic disease (CAD) and healthy controls have not been performed to date. We reviewed 67 patients with MMD undergoing Xenon-enhanced computed tomography, as well as 108 patients with CAD and 5 controls. In addition to cortical, central, and infratentorial regions of interest, particular emphasis was put on regions that are typically involved in MMD (pericallosal territory, basal ganglia). Cerebral blood flow (CBF), cerebrovascular reserve capacity (CVRC), and hemodynamic stress distribution were calculated. MMD is characterized by a significant, ubiquitous decrease in CVRC and a cortical but not pericallosal decrease in CBF when compared with controls. Baseline perfusion is maintained within the basal ganglia, and hemodynamic stress distribution confirmed a relative preservation of central regions of interest in MMD, indicative for its characteristic proximal collateralization pattern. In MMD and CAD, cortical and central CBF decreased significantly with age, whereas CVRC and hemodynamic stress distribution are relatively unaffected by age. No difference in CVRC of comparable regions of interest was seen between MMD and CAD, but stress distribution was significantly higher in MMD, illustrating the functionality of the characteristic rete mirabilis. Our data provide quantitative support for a territory-specific perfusion pattern that is unique for MMD, including central preservation of CBF compared with controls and patients with CAD. This correlates well with its characteristic feature of proximal collateralization. CVRC and hemodynamic stress distribution seem to be more robust parameters than CBF alone for assessment of disease severity.

Decreased Vertebral Artery Hemodynamics in Patients with Loss of Cervical Lordosis

PubMed Central

Bulut, Mehmet Deniz; Alpayci, Mahmut; Şenköy, Emre; Bora, Aydin; Yazmalar, Levent; Yavuz, Alpaslan; Gülşen, İsmail

2016-01-01

Background Because loss of cervical lordosis leads to disrupted biomechanics, the natural lordotic curvature is considered to be an ideal posture for the cervical spine. The vertebral arteries proceed in the transverse foramen of each cervical vertebra. Considering that the vertebral arteries travel in close anatomical relationship to the cervical spine, we speculated that the loss of cervical lordosis may affect vertebral artery hemodynamics. The aim of this study was to compare the vertebral artery values between subjects with and without loss of cervical lordosis. Material/Methods Thirty patients with loss of cervical lordosis and 30 controls matched for age, sex, and body mass index were included in the study. Sixty vertebral arteries in patients with loss of cervical lordosis and 60 in controls without loss of cervical lordosis were evaluated by Doppler ultrasonography. Vertebral artery hemodynamics, including lumen diameter, flow volume, peak systolic velocity, end-diastolic velocity, and resistive index, were measured, and determined values were statistically compared between the patient and the control groups. Results The means of diameter (p=0.003), flow volume (p=0.002), and peak systolic velocity (p=0.014) in patients were significantly lower as compared to controls. However, there was no significant difference between the 2 groups in terms of the end-diastolic velocity (p=0.276) and resistive index (p=0.536) parameters. Conclusions The present study revealed a significant association between loss of cervical lordosis and decreased vertebral artery hemodynamics, including diameter, flow volume, and peak systolic velocity. Further studies are required to confirm these findings and to investigate their possible clinical implications. PMID:26876295

Decreased Vertebral Artery Hemodynamics in Patients with Loss of Cervical Lordosis.

PubMed

Bulut, Mehmet Deniz; Alpayci, Mahmut; Şenköy, Emre; Bora, Aydin; Yazmalar, Levent; Yavuz, Alpaslan; Gülşen, İsmail

2016-02-15

BACKGROUND Because loss of cervical lordosis leads to disrupted biomechanics, the natural lordotic curvature is considered to be an ideal posture for the cervical spine. The vertebral arteries proceed in the transverse foramen of each cervical vertebra. Considering that the vertebral arteries travel in close anatomical relationship to the cervical spine, we speculated that the loss of cervical lordosis may affect vertebral artery hemodynamics. The aim of this study was to compare the vertebral artery values between subjects with and without loss of cervical lordosis. MATERIAL AND METHODS Thirty patients with loss of cervical lordosis and 30 controls matched for age, sex, and body mass index were included in the study. Sixty vertebral arteries in patients with loss of cervical lordosis and 60 in controls without loss of cervical lordosis were evaluated by Doppler ultrasonography. Vertebral artery hemodynamics, including lumen diameter, flow volume, peak systolic velocity, end-diastolic velocity, and resistive index, were measured, and determined values were statistically compared between the patient and the control groups. RESULTS The means of diameter (p=0.003), flow volume (p=0.002), and peak systolic velocity (p=0.014) in patients were significantly lower as compared to controls. However, there was no significant difference between the 2 groups in terms of the end-diastolic velocity (p=0.276) and resistive index (p=0.536) parameters. CONCLUSIONS The present study revealed a significant association between loss of cervical lordosis and decreased vertebral artery hemodynamics, including diameter, flow volume, and peak systolic velocity. Further studies are required to confirm these findings and to investigate their possible clinical implications.

Preoperative partitioning of pulmonary vascular resistance correlates with early outcome after thromboendarterectomy for chronic thromboembolic pulmonary hypertension.

PubMed

Kim, Nick H S; Fesler, Pierre; Channick, Richard N; Knowlton, Kirk U; Ben-Yehuda, Ori; Lee, Stephen H; Naeije, Robert; Rubin, Lewis J

2004-01-06

Pulmonary thromboendarterectomy (PTE) is the preferred treatment for chronic thromboembolic pulmonary hypertension (CTEPH), but persistent pulmonary hypertension after PTE, as a result of either inaccessible distal thrombotic material or coexistent intrinsic small-vessel disease, remains a major determinant of poor outcome. Conventional preoperative evaluation is unreliable in identifying patients at risk for persistent pulmonary hypertension or predicting postoperative hemodynamic outcome. We postulated that pulmonary arterial occlusion pressure waveform analysis, a technique that has been used for partitioning pulmonary vascular resistance, might identify CTEPH patients with significant distal, small-vessel disease. Twenty-six patients underwent preoperative right heart catheterization before PTE. Pulmonary artery occlusion waveform recordings were performed in triplicate. Postoperative hemodynamics after PTE were compared with preoperative partitioning of pulmonary vascular resistance derived from the occlusion data. Preoperative assessment of upstream resistance (Rup) correlated with both postoperative total pulmonary resistance index (R2=0.79, P<0.001) and postoperative mean pulmonary artery pressure (R2=0.75, P<0.001). All 4 postoperative deaths occurred in patients with a preoperative Rup <60%. Pulmonary arterial occlusion pressure waveform analysis may identify CTEPH patients at risk for persistent pulmonary hypertension and poor outcome after PTE. Patients with CTEPH and Rup value <60% appear to be at highest risk.

Cerebral hemodynamic changes in stroke during sleep-disordered breathing.

PubMed

Pizza, Fabio; Biallas, Martin; Kallweit, Ulf; Wolf, Martin; Bassetti, Claudio L

2012-07-01

Sleep-disordered breathing (SDB) negatively impacts stroke outcome. Near-infrared spectroscopy showed the acute cerebral hemodynamic effects of SDB. Eleven patients (7 men, age 61±13 years) with acute/subacute middle cerebral artery stroke (National Institutes of Health Stroke Scale score 10±7) and SDB (apnea-hypopnea index 32±28/hour) were assessed with nocturnal polysomnography and bilateral near-infrared spectroscopy recording. Cerebral oxygenation and hemoglobin concentration changes during obstructive and central apneas were analyzed. During SDB, near-infrared spectroscopy showed asymmetrical patterns of cerebral oxygenation and hemoglobin concentrations with changes significantly larger on the unaffected compared with the affected hemisphere. Brain tissue hypoxia was more severe during obstructive compared with central apneas. Profound cerebral deoxygenation effects of SDB occurred in acute/subacute stroke. These changes may contribute to poor outcome, arising in the possibility of a potential benefit of SDB treatment in stroke management.

Resistance to Fluid Shear Stress Is a Conserved Biophysical Property of Malignant Cells

PubMed Central

Henry, Michael D.

2012-01-01

During metastasis, cancer cells enter the circulation in order to gain access to distant tissues, but how this fluid microenvironment influences cancer cell biology is poorly understood. A longstanding view is that circulating cancer cells derived from solid tissues may be susceptible to damage from hemodynamic shear forces, contributing to metastatic inefficiency. Here we report that compared to non-transformed epithelial cells, transformed cells are remarkably resistant to fluid shear stress (FSS) in a microfluidic protocol, exhibiting a biphasic decrease in viability when subjected to a series of millisecond pulses of high FSS. We show that magnitude of FSS resistance is influenced by several oncogenes, is an adaptive and transient response triggered by plasma membrane damage and requires extracellular calcium and actin cytoskeletal dynamics. This novel property of malignant cancer cells may facilitate hematogenous metastasis and indicates, contrary to expectations, that cancer cells are quite resistant to destruction by hemodynamic shear forces. PMID:23226552

Hemodynamic adaptation to suboptimal fetal growth in patients with single ventricle physiology.

PubMed

Alsaied, Tarek; Tseng, Stephanie; King, Eileen; Hahn, Eunice; Divanovic, Allison; Habli, Mounira; Cnota, James

2018-06-10

In fetuses with structurally normal heart and suboptimal fetal growth (SFG), umbilical artery vascular resistance increases as measured by umbilical artery pulsatility index (UA-PI). The objective of this study is to compare hemodynamic responses to SFG in fetuses with single ventricle (SV) and controls with structurally normal heart. Fetal echocardiograms around 30 weeks of gestation were reviewed. UA-PI and middle cerebral artery pulsatility index (MCA-PI) were calculated. SFG was defined as a birth weight below 25th percentile for gestational age. Studies from 92 fetuses were reviewed-SV (n = 50) and controls (n = 42). The prevalence of SFG was higher in SV compared to controls (46% vs 21%, P = .02). In patients with normal heart and SFG, UAPI was significantly higher than normal controls (P = .003) suggesting increased placental vascular resistance. In SV with SFG there was no difference in UAPI compared to SV without SFG. There was no difference in MCA-PI between the groups. The hemodynamic response to SFG in SV varies from fetuses with structurally normal heart. The mechanism of SFG and the placental pathology may be distinct in SV. © 2018 Wiley Periodicals, Inc.

[The adrenergic mechanisms are involved in the pulmonary hemodynamics changes following experimental myocardial ischemia in rabbits].

PubMed

Evlakhov, V I; Poiasov, I Z

2012-05-01

In acute experiments in anesthetized rabbits the changes of the pulmonary hemodynamics following myocardial ischemia in the region of the descendent left coronary artery were studied in control animals and after the blockade of alpha-adrenoreceptors by phentolamine or N-cholinoreceptors of autonomic ganglia by hexamethonium. Following myocardial ischemia in control animals the pulmonary artery pressure and flow decreased, the pulmonary vascular resistance was elevated not significantly, the cardiac output decreased more than pulmonary artery flow. Following myocardial ischemia after the blockade of alpha-adrenoreceptors the pulmonary artery flow and cardiac output decreased in the same level and the pulmonary vascular resistance was decreased. In these conditions the pulmonary artery pressure decreased more than in control animals, meanwhile the pulmonary artery flow was decreased in the same level as in the last case. Following myocardial ischemia after the blockade of N-cholinoreceptors the pulmonary hemodynamics changes were the same as they were following myocardial ischemia in the control rabbits, the cardiac output decreased more than pulmonary artery flow. The disbalance of the cardiac output and pulmonary artery flow changes in the case of myocardial ischemia was caused by the pulmonary vessel reactions following activations of the humoral adrenergic mechanisms.

Using impedance cardiography to detect asymptomatic cardiovascular disease in prehypertensive adults with risk factors.

PubMed

DeMarzo, Arthur P

2013-06-01

Early detection of cardiovascular disease (CVD) in prehypertension could initiate appropriate treatment and prevent progression. Impedance cardiography (ICG) is a noninvasive technology that can be used to assess cardiovascular function. This study used ICG waveform analysis with postural change to detect CVD in asymptomatic prehypertensive adults over 40 years of age with no history of CVD and at least 2 cardiovascular risk factors: cigarette smoking, poor diet, physical inactivity, central obesity, family history of premature CVD, elevated blood glucose, and dyslipidemia. A study group of 25 apparently healthy adults was tested by ICG in standing and supine positions. Criteria for an age-matched control group of 16 healthy subjects included an active lifestyle, no risk factor, and no history of CVD. In addition to hemodynamic measurements of systemic vascular resistance (SVR) and cardiac index (CI), ICG used SVR to assess vascular resistive load, an index of arterial compliance and a widening of the systolic waveform to assess vascular pulsatile load, and waveform analysis and measured wave amplitude to detect ventricular dysfunction. All subjects in the study group had some abnormal ICG data, with an average of 2.9 ± 1.5 abnormalities per person. ICG indicated that 24 (96%) had elevated vascular load, 13 (52%) had some type of ventricular dysfunction, and 12 (48%) had abnormal hemodynamics. For the control group, ICG showed none (0%) with elevated vascular load, none (0%) with ventricular dysfunction, and 7 (44%) with high CI. Prehypertensives over 40 years of age with multiple risk factors have different cardiovascular abnormalities. This ICG test could be used as part of a prevention program for early detection of CVD. An abnormal ICG test could expedite the initiation of customized treatment that targets the subclinical CVD.

A machine learning approach to identify functional biomarkers in human prefrontal cortex for individuals with traumatic brain injury using functional near-infrared spectroscopy.

PubMed

Karamzadeh, Nader; Amyot, Franck; Kenney, Kimbra; Anderson, Afrouz; Chowdhry, Fatima; Dashtestani, Hadis; Wassermann, Eric M; Chernomordik, Victor; Boccara, Claude; Wegman, Edward; Diaz-Arrastia, Ramon; Gandjbakhche, Amir H

2016-11-01

We have explored the potential prefrontal hemodynamic biomarkers to characterize subjects with Traumatic Brain Injury (TBI) by employing the multivariate machine learning approach and introducing a novel task-related hemodynamic response detection followed by a heuristic search for optimum set of hemodynamic features. To achieve this goal, the hemodynamic response from a group of 31 healthy controls and 30 chronic TBI subjects were recorded as they performed a complexity task. To determine the optimum hemodynamic features, we considered 11 features and their combinations in characterizing TBI subjects. We investigated the significance of the features by utilizing a machine learning classification algorithm to score all the possible combinations of features according to their predictive power. The identified optimum feature elements resulted in classification accuracy, sensitivity, and specificity of 85%, 85%, and 84%, respectively. Classification improvement was achieved for TBI subject classification through feature combination. It signified the major advantage of the multivariate analysis over the commonly used univariate analysis suggesting that the features that are individually irrelevant in characterizing the data may become relevant when used in combination. We also conducted a spatio-temporal classification to identify regions within the prefrontal cortex (PFC) that contribute in distinguishing between TBI and healthy subjects. As expected, Brodmann areas (BA) 10 within the PFC were isolated as the region that healthy subjects (unlike subjects with TBI), showed major hemodynamic activity in response to the High Complexity task. Overall, our results indicate that identified temporal and spatio-temporal features from PFC's hemodynamic activity are promising biomarkers in classifying subjects with TBI.

Fluid-Structure Interaction Modeling of Intracranial Aneurysm Hemodynamics: Effects of Different Assumptions

NASA Astrophysics Data System (ADS)

Rajabzadeh Oghaz, Hamidreza; Damiano, Robert; Meng, Hui

2015-11-01

Intracranial aneurysms (IAs) are pathological outpouchings of cerebral vessels, the progression of which are mediated by complex interactions between the blood flow and vasculature. Image-based computational fluid dynamics (CFD) has been used for decades to investigate IA hemodynamics. However, the commonly adopted simplifying assumptions in CFD (e.g. rigid wall) compromise the simulation accuracy and mask the complex physics involved in IA progression and eventual rupture. Several groups have considered the wall compliance by using fluid-structure interaction (FSI) modeling. However, FSI simulation is highly sensitive to numerical assumptions (e.g. linear-elastic wall material, Newtonian fluid, initial vessel configuration, and constant pressure outlet), the effects of which are poorly understood. In this study, a comprehensive investigation of the sensitivity of FSI simulations in patient-specific IAs is investigated using a multi-stage approach with a varying level of complexity. We start with simulations incorporating several common simplifications: rigid wall, Newtonian fluid, and constant pressure at the outlets, and then we stepwise remove these simplifications until the most comprehensive FSI simulations. Hemodynamic parameters such as wall shear stress and oscillatory shear index are assessed and compared at each stage to better understand the sensitivity of in FSI simulations for IA to model assumptions. Supported by the National Institutes of Health (1R01 NS 091075-01).

Social cognition and prefrontal hemodynamic responses during a working memory task in schizophrenia.

PubMed

Pu, Shenghong; Nakagome, Kazuyuki; Yamada, Takeshi; Itakura, Masashi; Yamanashi, Takehiko; Yamada, Sayaka; Masai, Mieko; Miura, Akihiko; Yamauchi, Takahira; Satake, Takahiro; Iwata, Masaaki; Nagata, Izumi; Roberts, David L; Kaneko, Koichi

2016-03-01

Social cognition is an important determinant of functional impairment in schizophrenia, but its relationship with the prefrontal functional abnormalities associated with the condition is still unclear. The present study aimed to explore the relationship between social cognition and prefrontal function in patients with schizophrenia using 52-channel near-infrared spectroscopy (NIRS). Twenty-six patients with schizophrenia and 26 age-, gender-, and intelligence quotient-matched healthy controls (HCs) participated in the study. Hemodynamic responses in the prefrontal and superior temporal cortical regions were assessed during a working memory task using NIRS. Social cognition was assessed using the Social Cognition Screening Questionnaire (SCSQ). The observed hemodynamic responses were significantly reduced in the lateral prefrontal cortex (PFC), the frontopolar cortex, and temporal regions in subjects with schizophrenia compared to HCs. Additionally, lateral PFC hemodynamic responses assessed during the working memory task demonstrated a strong positive correlation with the SCSQ theory of mind (ToM) subscale score even after controlling for working memory performance. These results suggest that ToM integrity is closely related to lateral PFC functional abnormalities found in patients with schizophrenia. In addition, this study provides evidence to suggest that NIRS could be used to identify biomarkers of social cognition function in subjects with schizophrenia.

Reversible sympathetic vasomotor dysfunction in POTS patients.

PubMed

Freitas, J; Santos, R; Azevedo, E; Costa, O; Carvalho, M; de Freitas, A F

2000-11-01

Orthostatic intolerance refers to the development upon assuming an upright posture of disabling symptoms, which are partly relieved by resuming the supine position. Postural tachycardia syndrome (POTS) is an orthostatic intolerance syndrome characterized by palpitations due to excessive orthostatic sinus tachycardia, lightheadedness, tremor, and near-syncope. Patients usually undergo extensive medical, cardiac, endocrine, neurological and psychiatric evaluation, which usually fails to identify a specific abnormality. We investigated the autonomic and hemodynamic profile of POTS patients and the efficacy of bisoprolol and or fludrocortisone. We evaluated eleven female patients with POTS before and after medical treatment with a cardio-selective beta blocker (bisoprolol) and/or fludrocortisone, and eleven age-matched controls. Variability of heart rate and systolic blood pressure was assessed by Fast Fourier Transform, and spontaneous baroreceptor gain by temporal sequences slope and alpha index. Modelflow was used to quantify hemodynamics. All patients improved greatly after medication. The autonomic and hemodynamic impairment observed in patients with POTS, particularly after orthostatic stress, is treated effectively with bisoprolol and/or fludrocortisone. These results need further confirmation in a controlled double-blind study. Proper medical treatment dramatically improves the clinical and autonomic/hemodynamic disturbances observed in patients with POTS. The data support the hypothesis that POTS is due to a hyperadrenergic activation and/or hypovolemia during orthostasis.

Simultaneous diffuse near-infrared imaging of hemodynamic and oxygenation changes and electroencephalographic measurements of neuronal activity in the human brain

NASA Astrophysics Data System (ADS)

Noponen, Tommi; Kicic, Dubravko; Kotilahti, Kalle; Kajava, Timo; Kahkonen, Seppo; Nissila, Ilkka; Merilainen, Pekka; Katila, Toivo

2005-04-01

Visually evoked hemodynamic responses and potentials were simultaneously measured using a 16-channel optical imaging instrument and a 60-channel electroencephalography instrument during normo-, hypo- and hypercapnia from three subjects. Flashing and pattern-reversed checkerboard stimuli were used. The study protocol included two counterbalanced measurements during both normo- and hypocapnia and normo- and hypercapnia. Hypocapnia was produced by controlled hyperventilation and hypercapnia by breathing carbon dioxide enriched air. Near-infrared imaging was also used to monitor the concentration changes of oxy- and deoxyhaemoglobin due to hypo- and hypercapnia. Hemodynamic responses and evoked potentials were successfully detected for each subject above the visual cortex. The latencies of the hemodynamic responses during hypocapnia were shorter whereas during hypercapnia they were longer when compared to the latencies during normocapnia. Hypocapnia tended to decrease the latencies of visually evoked potentials compared to those during normocapnia while hypercapnia did not show any consistent effect to the potentials. The developed measurement setup and the study protocol provide the opportunity to investigate the neurovascular coupling and the links between the baseline level of blood flow, electrical activity and hemodynamic responses in the human brain.

Time-Frequency Characterization of Cerebral Hemodynamics of Migraine Sufferers as Assessed by NIRS Signals

NASA Astrophysics Data System (ADS)

Molinari, Filippo; Rosati, Samanta; Liboni, William; Negri, Emanuela; Mana, Ornella; Allais, Gianni; Benedetto, Chiara

2010-12-01

Near-infrared spectroscopy (NIRS) is a noninvasive system for the real-time monitoring of the concentration of oxygenated ([InlineEquation not available: see fulltext.]) and reduced (HHb) hemoglobin in the brain cortex. [InlineEquation not available: see fulltext.] and HHb concentrations vary in response to cerebral autoregulation. Sixty-eight women (14 migraineurs without aura, 49 migraineurs with aura, and 5 controls) performed breath-holding and hyperventilation during NIRS recordings. Signals were processed using the Choi-Williams time-frequency transform in order to measure the power variation of the very-low frequencies (VLF: 20-40 mHz) and of the low frequencies (LF: 40-140 mHz). Results showed that migraineurs without aura present different LF and VLF power levels than controls and migraineurs with aura. The accurate power measurement of the time-frequency analysis allowed for the discrimination of the subjects' hemodynamic patterns. The time-frequency analysis of NIRS signals can be used in clinical practice to assess cerebral hemodynamics.

Empirical Evaluation of Visual Fatigue from Display Alignment Errors Using Cerebral Hemodynamic Responses

PubMed Central

Wiyor, Hanniebey D.; Ntuen, Celestine A.

2013-01-01

The purpose of this study was to investigate the effect of stereoscopic display alignment errors on visual fatigue and prefrontal cortical tissue hemodynamic responses. We collected hemodynamic data and perceptual ratings of visual fatigue while participants performed visual display tasks on 8 ft × 6 ft NEC LT silver screen with NEC LT 245 DLP projectors. There was statistical significant difference between subjective measures of visual fatigue before air traffic control task (BATC) and after air traffic control task (ATC 3), (P < 0.05). Statistical significance was observed between left dorsolateral prefrontal cortex oxygenated hemoglobin (l DLPFC-HbO2), left dorsolateral prefrontal cortex deoxygenated hemoglobin (l DLPFC-Hbb), and right dorsolateral prefrontal cortex deoxygenated hemoglobin (r DLPFC-Hbb) on stereoscopic alignment errors (P < 0.05). Thus, cortical tissue oxygenation requirement in the left hemisphere indicates that the effect of visual fatigue is more pronounced in the left dorsolateral prefrontal cortex. PMID:27006917

The effect of low-dose dexmedetomidine on hemodynamics and anesthetic requirement during bis-spectral index-guided total intravenous anesthesia.

PubMed

Park, Hee Yeon; Kim, Jong Yeop; Cho, Sang Hyun; Lee, Dongchul; Kwak, Hyun Jeong

2016-08-01

The purpose of this study was to evaluate the effects of low-dose dexmedetomidine on hemodynamics and anesthetic requirements during propofol and remifentanil anesthesia for laparoscopic cholecystectomy. Thirty adult patients were randomly allocated to receive dexmedetomidine infusion of 0.3 μg/kg/h (dexmedetomidine group, n = 15) or comparable volumes of saline infusion (control group, n = 15). Target controlled infusion of propofol and remifentanil was used for anesthetic induction and maintenance, and adjusted in order to maintain a bispectral index of 40-55 and hemodynamic stability. We measured hemodynamics and recorded total and mean infused dosages of propofol and remifentanil. For anesthesia induction and maintenance, mean infused doses of propofol (121 ± 27 vs. 144 ± 29 μg/kg/min, P = 0.04) and remifentanil (118 ± 27 vs. 150 ± 36 ng/kg/min, P = 0.01) were lower in the dexmedetomidine group than in the control group, respectively. The dexmedetomidine group required 16 % less propofol and 23 % less remifentanil. During anesthetic induction and maintenance, the dexmedetomidine group required fewer total doses of propofol (9.6 ± 2.3 vs. 12.4 ± 3.3 mg/kg, P = 0.01) and remifentanil (9.6 ± 3.4 vs. 12.7 ± 2.6 μg/kg, P = 0.01). The change in mean arterial pressure over time differed between the groups (P < 0.05). Significantly lower mean arterial pressure was observed in the dexmedetomidine group than in the control group at immediately and 5 min after pneumoperitoneum. The time to extubation after completion of drug administration did not differ between the groups (P = 0.25). This study demonstrated that a low-dose dexmedetomidine infusion of 0.3 μg/kg/h reduced propofol and remifentanil requirements as well as hemodynamic change by pneumoperitoneum without delayed recovery during propofol-remifentanil anesthesia for laparoscopic cholecystectomy.

Hemodynamics Associated with Breathing Through an Inspiratory Impedance Threshold Device in Human Volunteers

DTIC Science & Technology

2004-01-01

nerve stimulation combined with an inspiratory impedance threshold in a pig model of hemorrhagic shock. Crit Care Med 2003; 31:1197–1202 16. Coast JR...training. Because of the po- tential effects on cardiovascular function, sub- jects refrained from exercise and stimulants such as caffeine and other...controlled trial. Setting: Laboratory. Subjects: Ten women and ten men. Interventions: We measured hemodynamic and respiratory re- sponses during two

Portal response related to shunt occlusion by balloon-occluded retrograde transvenous obliteration may determine the prognosis of cirrhosis.

PubMed

Kobayashi, Kazufumi; Maruyama, Hitoshi; Kiyono, Soichiro; Sekimoto, Tadashi; Kondo, Takayuki; Shimada, Taro; Takahashi, Masanori; Okugawa, Hidehiro; Yokosuka, Osamu

2016-12-01

To determine the prognostic effect of portal hemodynamic responses after balloon-occluded retrograde transvenous obliteration (B-RTO) for gastric varices (GV) in cirrhosis patients. This retrospective study consisted of 37 cirrhosis patients (aged 62.5 ± 9.7 years) with medium- or large-grade GV treated with B-RTO. Portal hemodynamic response was assessed by the changes in flow volume in the portal trunk (PFV, mL/min) before and after the treatment. Group I showed increased PFV and group II showed no increase in PFV. The median observation period was 49.8 months (range, 4.7-150.3 months). All patients showed complete embolization of GV without any recurrence. There were 30 patients in group I and 7 patients in group II (decreased PFV in 6 and unchanged PFV in 1). The PFV at baseline was significantly lower in the former (583.5 ± 232.0 mL/min) than in the latter (880.7 ± 345.9 mL/min; P = 0.009). The survival rate was significantly lower in group II (83.3% at 1 year and 66.7% at 3 years) than in group I (96.7% at 1 year, 81.5% at 3 years, and 61.8% at 5 years; P = 0.012). The incidence of deterioration of the esophageal varices was 18/30 (60%) in group I and 5/7 (71.4%; P = 0.687) in group II. Multivariate analysis identified only no increase in portal response (hazard ratio, 8.086; P = 0.005) as an independent factor for poor prognosis. Balloon-occluded retrograde transvenous obliteration for GV may result in a poor prognosis when portal hemodynamics shows no increase in portal response. © 2016 The Japan Society of Hepatology.

[Damage control in trauma patients with hemodynamic instability].

PubMed

Müller, Thorben; Doll, Dietrich; Kliebe, Frank; Ruchholtz, Steffen; Kühne, Christian

2010-10-01

The term "Damage-control" is borrowed from naval terminology. It means the initial control of a damaged ship. Because of the lethal triad in multiple injured patients the classical concept of definitive surgically therapy in the acute phase of the injury has a high rate of complications such as exsanguination, sepsis, heart failure and multiple organ failure. The core idea of the damage control concept was to minimize the additional trauma by surgical operations in these critical patients in the first phase. This means temporary control of a hemorrhage and measures for stopping abdominal contamination. After 24 - 48 hours in the intensive care unit and correction of physiological disturbances further interventions are performed for definitively treatment of the injuries. Summarized, the damage control strategy comprises an abbreviated operation, intensive care unit resuscitation, and a return to the operating room for the definitive operation after hemodynamic stabilisation of the patient. © Georg Thieme Verlag Stuttgart · New York.

Effect of music on labor pain relief, anxiety level and postpartum analgesic requirement: a randomized controlled clinical trial.

PubMed

Simavli, Serap; Gumus, Ilknur; Kaygusuz, Ikbal; Yildirim, Melahat; Usluogullari, Betul; Kafali, Hasan

2014-01-01

The control of labor pain and the prevention of suffering are major concerns of clinicians and their patients. The aim of this study was to evaluate the effect of music on labor pain and anxiety, maternal hemodynamics, fetal-neonatal parameters and postpartum analgesic requirement in primiparous women. Overall, 156 primiparous women who expected vaginal delivery were recruited and randomly assigned to a music group (n = 77) or a control group (n = 79). Women in the music group listened to music during labor. Pain intensity and anxiety level were measured using a visual analogue scale (0-10 cm). The two groups were compared in terms of pain severity, anxiety level, maternal hemodynamics, fetal-neonatal parameters and postpartum analgesic requirement. Mothers in the music therapy group had a lower level of pain and anxiety compared with those in the control group at all stages of labor (p < 0.001). A significant difference was observed between the two groups in terms of maternal hemodynamics and fetal heart rate after intervention (p < 0.01). Postpartum analgesic requirement significantly decreased in the music therapy group (p < 0.01). Listening to music during labor has a positive impact on labor pain and anxiety, maternal-fetal parameters and analgesic requirement. © 2014 S. Karger AG, Basel.

Association of cardiac troponin I with disease severity and outcomes in patients with pulmonary hypertension.

PubMed

Vélez-Martínez, Mariella; Ayers, Colby; Mishkin, Joseph D; Bartolome, Sonja B; García, Christine K; Torres, Fernando; Drazner, Mark H; de Lemos, James A; Turer, Aslan T; Chin, Kelly M

2013-06-15

Previous studies have identified cardiac troponin I (cTnI) as an important marker in pulmonary hypertension (PH) prognosis. However, traditional assays are limited by poor sensitivity, even among patients at high risk. cTnI was measured in 255 PH patients using a new highly sensitive (hs) assay. Other measures included demographics, creatinine, 6-minute walk distance, hemodynamics, cardiac magnetic resonance imaging, and B-type natriuretic peptide level. The association between cTnI and survival was assessed using Kaplan-Meier analysis and Cox regression. cTnI was detectable with the hs assay in 95% of the patients with a median level of 6.9 pg/ml (IQR 2.7-12.6 pg/ml). Higher cTnI levels associated with higher levels of B-type natriuretic peptide, shorter 6-minute walk distance, and more severe hemodynamic and cardiac magnetic resonance imaging abnormalities. During a median follow-up of 3.5 years, 60 individuals died. Unadjusted event rates increased across higher cTnI quartiles (3, 5, 13, 17 events/100 person-years, respectively, p trend = 0.002). cTnI in the fourth (vs first) quartile remained associated with death in a final stepwise multivariable model that included clinical variables and hemodynamics (adjusted hazard ratio 5.3, 95% confidence interval 1.8-15.6). In conclusion, cTnI levels, detectable with a novel hs assay, identify patients with PH who have more severe hemodynamic and cardiac structural abnormalities and provide novel and independent prognostic information. This hs assay has the potential to detect more at-risk patients and improve current risk-stratification algorithms. Copyright © 2013 Elsevier Inc. All rights reserved.

The influence of systemic hemodynamics and oxygen transport on cerebral oxygen saturation in neonates after the Norwood procedure.

PubMed

Li, Jia; Zhang, Gencheng; Holtby, Helen; Guerguerian, Anne-Marie; Cai, Sally; Humpl, Tilman; Caldarone, Christopher A; Redington, Andrew N; Van Arsdell, Glen S

2008-01-01

Ischemic brain injury is an important morbidity in neonates after the Norwood procedure. Its relationship to systemic hemodynamic oxygen transport is poorly understood. Sixteen neonates undergoing the Norwood procedure were studied. Continuous cerebral oxygen saturation was measured by near-infrared spectroscopy. Continuous oxygen consumption was measured by respiratory mass spectrometry. Pulmonary and systemic blood flow, systemic vascular resistance, oxygen delivery, and oxygen extraction ratio were derived with measurements of arterial, and superior vena cava and pulmonary venous gases and pressures at 2- to 4-hour intervals during the first 72 hours in the intensive care unit. Mean cerebral oxygen saturation was 66% +/- 12% before the operation, reduced to 51% +/- 13% on arrival in the intensive care unit, and remained low during the first 8 hours; it increased to 56% +/- 9% at 72 hours, still significantly lower than the preoperative level (P < .05). Postoperatively, cerebral oxygen saturation was closely and positively correlated with systemic arterial pressure, arterial oxygen saturation, and arterial oxygen tension and negatively with oxygen extraction ratio (P < .0001 for all). Cerebral oxygen saturation was moderately and positively correlated with systemic blood flow and oxygen delivery (P < .0001 for both). It was weakly and positively correlated with pulmonary blood flow (P = .001) and hemoglobin (P = .02) and negatively correlated with systemic vascular resistance (P = .003). It was not correlated with oxygen consumption (P > .05). Cerebral oxygen saturation decreased significantly in neonates during the early postoperative period after the Norwood procedure and was significantly influenced by systemic hemodynamic and metabolic events. As such, hemodynamic interventions to modify systemic oxygen transport may provide further opportunities to reduce the risk of cerebral ischemia and improve neurodevelopmental outcomes.

Pacing-induced congenital heart defects assessed by OCT (Conference Presentation)

NASA Astrophysics Data System (ADS)

Ford, Stephanie M.; McPheeters, Matt T.; Wang, Yves T.; Gu, Shi; Doughman, Yong Qiu; Strainic, James P.; Rollins, Andrew M.; Watanabe, Michiko; Jenkins, Michael W.

2016-03-01

The role of hemodynamics in early heart development is poorly understood. In order to successfully assess the impact of hemodynamics on development, we need to monitor and perturb blood flow, and quantify the resultant effects on morphology. Here, we have utilized cardiac optical pacing to create regurgitant flow in embryonic hearts and OCT to quantify regurgitation percentage and resultant morphology. Embryonic quail in a shell-less culture were optically paced at 3 Hz (well above the intrinsic rate or 1.33-1.67 Hz) on day 2 of development (3-4 weeks human) for 5 minutes. The pacing fatigued the heart and led to a prolonged period (> 1 hour) of increased regurgitant flow. Embryos were kept alive until day 3 (cardiac looping - 4-5 weeks human) or day 8 (4 chambered heart - 8 weeks human) to quantify resultant morphologic changes with OCT. All paced embryos imaged at day 3 displayed cardiac defects. The extent of regurgitant flow immediately after pacing was correlated with cardiac cushion size 24-hours post pacing (p-value < 0.01) with higher regurgitation leading to smaller cushions. Almost all embryos (16/18) surviving to day 8 exhibited congenital heart defects (CHDs) including 11/18 with valve defects, 5/18 with ventricular septal defects and 5/18 with hypoplastic right ventricles. Our data suggests that regurgitant flow leads to smaller cushions, which develop into abnormal valves and septa. Our model produces similar phenotypes as found in our fetal alcohol syndrome and velo-cardio-facial/DiGeorge syndrome models suggesting that hemodynamics plays a role in these syndromes as well. Utilizing OCT and optical pacing to understand hemodynamics in development is an important step towards determining CHD mechanisms and ultimately developing earlier treatments.

The hemodynamic effects of intravenous paracetamol (acetaminophen) vs normal saline in cardiac surgery patients: A single center placebo controlled randomized study

PubMed Central

Churilov, Leonid

2018-01-01

The hemodynamic effects of intravenous (IV) paracetamol in patients undergoing cardiac surgery are unknown. We performed a prospective single center placebo controlled randomized study with parallel group design in adult patients undergoing elective cardiac surgery. Participants received paracetamol (1 gram) IV or placebo (an equal volume of 0.9% saline) preoperatively followed by two postoperative doses 6 hours apart. The primary endpoint was the absolute change in systolic (SBP) 30 minutes after the preoperative infusion, analysed using an ANCOVA model. Secondary endpoints included absolute changes in mean arterial pressure (MAP) and diastolic blood pressure (DPB), and other key hemodynamic variables after each infusion. All other endpoints were analysed using random-effect generalized least squares regression modelling with individual patients treated as random effects. Fifty participants were randomly assigned to receive paracetamol (n = 25) or placebo (n = 25). Post preoperative infusion, paracetamol decreased SBP by a mean (SD) of 13 (18) mmHg, p = 0.02, compared to a mean (SD) of 1 (11) mmHg with saline. Paracetamol decreased MAP and DBP by a mean (SD) of 9 (12) mmHg and 8 (9) mmHg (p = 0.01 and 0.02), respectively, compared to a mean (SD) of 1 (8) mmHg and 0 (6) mmHg with placebo. Postoperatively, there were no significant differences in pressure or flow based hemodynamic parameters in both groups. This study provides high quality evidence that the administration of IV paracetamol in patients undergoing cardiac surgery causes a transient decrease in preoperative blood pressure when administered before surgery but no adverse hemodynamic effects when administered in the postoperative setting. PMID:29659631

Clofibrate prevents and reverses the hemodynamic manifestations of hyperthyroidism in rats.

PubMed

Rodríguez-Gómez, Isabel; Cruz, Antonio; Moreno, Juan Manuel; Soler, Agatángelo; Osuna, Antonio; Vargas, Félix

2008-03-01

This study analyzed the effects of the chronic administration of clofibrate, a peroxisome proliferator-activated receptor-alpha (PPARalpha) agonist, on the development and established hemodynamic, morphologic, metabolic, and renal manifestations of hyperthyroidism in rats. The prevention study used four groups of male Wistar rats: control, clofibrate (240 mg/kg/day by gavage), T(4)(75 microg thyroxine/rat/day s.c.), and T(4)+clofibrate. All treatments were maintained for 3 weeks. Body weight (BW), tail systolic blood pressure (SBP), and heart rate (HR) were recorded weekly. Finally, temperature, SBP, pulse pressure (PP) and HR were recorded in conscious rats, and morphologic, metabolic, plasma, and renal variables were measured. The reversion study used two groups of rats, T(4)(treated for 6 weeks) and T(4)+clofibrate, measuring their hemodynamic variables and temperature for 3 weeks. T(4) increased BP, HR, PP, and temperature when compared with control rats. Clofibrate prevented and reversed the increase in SBP, HR, PP, and temperature produced by T(4) administration, reduced plasma thyroid hormone levels, and increased plasma thyroid-stimulating hormone values and phenol-uridine diphosphate-glucuronosyl-transferase (UGT) activity. However, clofibrate did not modify the cardiac or renal hypertrophy, polyphagia, polydipsia, or proteinuria of hyperthyroid rats. In normal rats, clofibrate treatment did not significantly change thyroid hormone levels, phenol-UGT activity, or any hemodynamic, morphologic, or renal variables. Chronic clofibrate treatment suppressed the hemodynamic manifestations and increased temperature of hyperthyroidism, an effect that can be produced by direct antithyroid effects. However, clofibrate administration did not modify the morphologic, metabolic, or renal alterations of hyperthyroid rats, indicating specificity in the antithyroid actions of clofibrate.

The hemodynamic effects of intravenous paracetamol (acetaminophen) vs normal saline in cardiac surgery patients: A single center placebo controlled randomized study.

PubMed

Chiam, Elizabeth; Bellomo, Rinaldo; Churilov, Leonid; Weinberg, Laurence

2018-01-01

The hemodynamic effects of intravenous (IV) paracetamol in patients undergoing cardiac surgery are unknown. We performed a prospective single center placebo controlled randomized study with parallel group design in adult patients undergoing elective cardiac surgery. Participants received paracetamol (1 gram) IV or placebo (an equal volume of 0.9% saline) preoperatively followed by two postoperative doses 6 hours apart. The primary endpoint was the absolute change in systolic (SBP) 30 minutes after the preoperative infusion, analysed using an ANCOVA model. Secondary endpoints included absolute changes in mean arterial pressure (MAP) and diastolic blood pressure (DPB), and other key hemodynamic variables after each infusion. All other endpoints were analysed using random-effect generalized least squares regression modelling with individual patients treated as random effects. Fifty participants were randomly assigned to receive paracetamol (n = 25) or placebo (n = 25). Post preoperative infusion, paracetamol decreased SBP by a mean (SD) of 13 (18) mmHg, p = 0.02, compared to a mean (SD) of 1 (11) mmHg with saline. Paracetamol decreased MAP and DBP by a mean (SD) of 9 (12) mmHg and 8 (9) mmHg (p = 0.01 and 0.02), respectively, compared to a mean (SD) of 1 (8) mmHg and 0 (6) mmHg with placebo. Postoperatively, there were no significant differences in pressure or flow based hemodynamic parameters in both groups. This study provides high quality evidence that the administration of IV paracetamol in patients undergoing cardiac surgery causes a transient decrease in preoperative blood pressure when administered before surgery but no adverse hemodynamic effects when administered in the postoperative setting.

Reduction of coenzyme q10 content: a possible effect of isoproterenol on heart failure and myocardial infarction in rat.

PubMed

Khorrami, A; Garjani, A; Ghanbarzadeh, S; Andalib, S

2014-04-01

Myocardial infarction (MI) was induced by subcutaneous injection of isoproterenol (ISO) to investigate the effect of ISO on Coenzyme Q10 (CoQ10) content of myocardium and subsequent effects on lipid peroxidation, electrocardiogram pattern and hemodynamic parameters of the rat's heart.36 male Wistar rats were divided randomly into 6 groups. To induce heart failure (HF) and MI, 10 and 100 mg/kg of ISO was administered subcutaneously for 10 and 2 consecutive days, respectively. The effects of ISO on myocardium CoQ10 content, concentration of malondialdehyde, ECG pattern and hemodynamic parameters of heart were analyzed.ISO-treated rats showed significant alteration in heart hemodynamic parameters such as reduction of left-ventricular systolic pressure, maximum and minimum rate of developed left ventricular pressure, besides increase of left ventricular end-diastolic pressure. Significant depletion of heart CoQ10 content (from 4.57 and 4.55 µg/100 mg tissue in control groups to 2.85 and 2.89 µg/100 mg tissue in ISO-induced HF and MI groups respectively) and increase in tissue levels of malondialdehyde (47.1 and 53.8 nmol/100 mg tissue in ISO-induced HF and MI groups, respectively) were also observed in ISO-treated animals compared with the normal animals (17.4 and 18.8 nmol/100 mg tissue in control groups, respectively). Additionally CoQ10 improved ISO effects on hemodynamic parameters and ECG pattern in ISO-induced HF and myocardial injury.The present findings have demonstrated that the cardiotoxic effects of ISO such as oxidative damage and hemodynamic declination might be related to depletion of CoQ10 concentration. © Georg Thieme Verlag KG Stuttgart · New York.

The effect of ephedrine on intraoperative hypothermia

PubMed Central

Jo, Youn Yi; Kim, Ji Young; Kim, Joon-Sik; Kwon, Youngjun

2011-01-01

Background Prevention of intraoperative hypothermia has become a standard of operative care. Since ephedrine has a thermogenic effect and it is frequently used to treat hypotension during anesthesia, this study was designed to determine the effect of ephedrine on intraoperative hypothermia of patients who are undergoing spine surgery. Methods Twenty-four patients were randomly divided to receive an ephedrine (the ephedrine group, n = 12) or normal saline (the control group, n = 12) infusion for 2 h. The esophageal temperature (the core temperature), the index finger temperature (the peripheral temperature) and the hemodynamic variables such as the mean blood pressure and heart rate were measured every 15 minutes after the intubation. Results At the end of the study period, the esophageal temperature and hemodynamic variables were significantly decreased in the control group, whereas those in the ephedrine group were stably maintained. The index finger temperature was significantly lower in the ephedrine group compared to that in the control group, suggesting the prevention of core-to-peripheral redistribution of the heat as the cause of temperature maintenance. Conclusions An intraoperative infusion of ephedrine minimized the decrease of the core temperature and it stably maintained the hemodynamic variables during spine surgery with the patient under general anesthesia. PMID:21602974

Hemodynamic parameters in a surgical devascularization model of fulminant hepatic failure in the minipig.

PubMed

Kieslichová, E; Ryska, M; Pantoflícek, T; Ryska, O; Zazula, R; Skobová, J

2005-01-01

Animal models of fulminant hepatic failure (FHF) are important for studying the pathophysiology of this process and for evaluation of the efficacy of artificial and bioartificial liver support systems. In experiments, hemodynamic parameters were monitored in a group of minipigs with FHF induced by surgical devascularization, and compared with those in a control group. During the experiment, animals were analgosedated and were on mechanical lung ventilation. Crystalloid and colloidal solutions were administered and norepinephrine in continuous infusion was applied if mean arterial pressure (MAP) decreased below 60 mm Hg despite adequate intravascular volumes. An increase in heart rate, and decreases in MAP and systemic vascular resistance, compared with the baseline, occurred in the FHF group from 6 h after surgery. A comparison of FHF and control groups revealed no significant differences in systemic vascular resistance and MAP until after 12 h after surgery (systemic vascular resistance index: 953 FHF vs. 1658 controls; p < 0.05; MAP: 58.1 FHF vs. 76 controls; p < 0.05). No significant differences in CI were seen between the FHF group and controls. FHF animals survived for about 13 h after surgery, i.e. a period, which we consider long enough to test a support device. The parameters are believed to be quite adequate, as we were able to maintain satisfactory hemodynamic stability in all experimental animals with induced acute hepatic failure.

Clinical improvement in patients with orthostatic intolerance after treatment with bisoprolol and fludrocortisone.

PubMed

Freitas, J; Santos, R; Azevedo, E; Costa, O; Carvalho, M; de Freitas, A F

2000-10-01

Orthostatic intolerance is the development of disabling symptoms upon assuming an upright posture that are relieved partially by resuming the supine position. Postural tachycardia syndrome (POTS) is an orthostatic intolerance syndrome characterized by palpitations because of excessive orthostatic sinus tachycardia, lightheadedness, tremor, and near-syncope. Patients usually undergo extensive medical, cardiac, endocrine, neurologic, and psychiatric evaluation, which usually fails to identify a specific abnormality. The authors investigated the autonomic and hemodynamic profile of patients with POTS and the effectiveness of bisoprolol and fludrocortisone. The authors evaluated 11 female patients with POTS before and after medical treatment with a cardioselective bisoprolol beta-blocker or fludrocortisone, or both, and 11 age-matched control patients. Variability of heart rate and systolic blood pressure was assessed by fast Fourier transform, and spontaneous baroreceptor gain was assessed by use of the temporal sequences slope and alpha index. Modelflow was used to quantify hemodynamics. Symptoms in all patients improved greatly after medication. The autonomic and hemodynamic impairment observed in patients with POTS, particularly after orthostatic stress, is treated effectively with bisoprolol or fludrocortisone or both. These results need further confirmation in a controlled double-blind study. Proper medical treatment improves dramatically the clinical and autonomic-hemodynamic disturbances observed in patients with POTS. The data support the hypothesis that POTS is the result of a hyperadrenergic activation or hypovolemia during orthostasis.

Cardioprotective role of H₃R agonist imetit on isoproterenol-induced hemodynamic changes and oxidative stress in rats.

PubMed

Yadav, Chander Hass; Najmi, Abul Kalam; Akhtar, Mohd; Khanam, Razia

2015-01-01

The cardioprotective role of histamine H3 receptor (H3R) agonist imetit (IMT) in isoproterenol (ISO)-induced alterations of hemodynamic and oxidative stress was investigated in Wistar rats. In this study, rats were treated with IMT (5 and 10 mg/kg, per orally [p.o.]), carvedilol (10 mg/kg, p.o.) and ISO control group (normal saline) for 7 d, with concurrent subcutaneous administration of ISO (85 mg/kg) at 24 h interval on last two consecutive days whereas control group was administered with vehicle only. ISO significantly attenuated cardiac antioxidant enzymes superoxide dismutase, catalase and increased plasma cardiac injury biomarkers creatine kinase-MB, alanine transaminase and aspartate transaminase. ISO also altered cardiac activity as evidenced by decrease in blood pressure (34.60%) and increase in heart rate (11.40%). The damage due to oxidative stress was revealed by histopathology alterations such as myocyte necrosis, myofibrillar degeneration and pyknotic nucleus. However, pre-treatment with IMT demonstrated restoration of hemodynamic alterations along with significant preservation of antioxidants and myocyte injury-specific marker enzymes. Furthermore, protective effect of IMT was reconfirmed by the histopathological salvage of myocardium. Results of the present study demonstrated the cardioprotective potential of IMT, as evidenced by favorable improvement in ISO-induced hemodynamic, plasma cardiac biomarkers and tissue antioxidant status along with maintenance of integrity of myocardium.

Protective effects of melatonin on ischemia-reperfusion induced myocardial damage and hemodynamic recovery in rats.

PubMed

Liu, L-F; Qin, Q; Qian, Z-H; Shi, M; Deng, Q-C; Zhu, W-P; Zhang, H; Tao, X-M; Liu, Y

2014-01-01

To investigate the mechanism of melatonin (MT) protection of adult rate myocardial ischemia-reperfusion injury and its influence on rat's hemodynamic recovery. 48 rats were randomly divided into MT group (n=36) and the control group (n=12), MT group was divided into three sub-groups according to different dosages: Group I (n=12) was administered with 2.5 mg/kg MT; Group II (n=12) was administered with 5 mg/kg MT; Group III (n=12) was administered with 10 mg/kg MT. The electrocardiogram of four groups was observed with the left coronary artery blocked for 10min at first and then reperfused for 15min. Hemodynamic evolving was observed and changes in energy metabolism of rat myocardium were monitored. TUNEL and immunohistochemistry were applied to detect the cell apoptosis index, protein expression of Bcl-2 and Bax. LVDP (left ventricular developed pressure) and ± dp/dt in MT group presented better recovery at various time points than the control group. Among them, Group III had the optimal recovery degree (p < 0.05). After MT administration, ATP content in myocardial cells in MT group was significantly higher than the control group. Compared with the control group, the concentration of mitochondrial MDA and Ca2+ in myocardial cells in MT group showed a downward trend. But its GSH concentration was significantly higher than the control group (p < 0.05). The improvement degree of ATP, MDA, GSH and Ca2+ concentration in Group II over-performed Group I (p < 0.05). MT-intervened myocardial apoptosis index (AI) and Bax positive expression index declined while Bcl-2 positive expression index increased (p < 0.01). MT effectively inhibited myocardial apoptosis during the myocardial ischemia-reperfusion of rats, protected the structural integrity of mitochondria in myocardial cells, promoted ATP synthesis, and avoided heart damage in many ways. This protection mechanism was related with anti-oxidative damage. Meanwhile, MT could promote the hemodynamic recovery after myocardial ischemia-reperfusion in rats.

Cerebral Hemodynamics and Systemic Endothelial Function Are Already Impaired in Well-Controlled Type 2 Diabetic Patients, with Short-Term Disease

PubMed Central

Altavilla, Riccardo; Di Flaviani, Alessandra; Giordani, Ilaria; Malandrucco, Ilaria; Picconi, Fabiana; Passarelli, Francesco; Pasqualetti, Patrizio; Ercolani, Matilde; Vernieri, Fabrizio; Frontoni, Simona

2013-01-01

Objective Impaired cerebral vasomotor reactivity (VMR) and flow-mediated dilation (FMD) were found in selected subgroups of type 2 diabetes mellitus (T2DM) patients with long-term disease. Our study aimed to evaluate cerebral hemodynamics, systemic endothelial function and sympatho-vagal balance in a selected population of well-controlled T2DM patients with short-term disease and without cardiac autonomic neuropathy (CAN). Research Design and Methods Twenty-six T2DM patients with short-term (4.40±4.80 years) and well-controlled (HbA1C = 6.71±1.29%) disease, without any complications, treated with diet and/or metformin, were consecutively recruited. Eighteen controls, comparable by sex and age, were enrolled also. Results FMD and shear rate FMD were found to be reduced in T2DM subjects with short-term disease (8.5% SD 3.5 and 2.5 SD 1.3, respectively) compared to controls (15.4% SD 4.1 and 3.5 SD 1.4; p<.001 and p<.05). T2DM patients also displayed reduced VMR values than controls (39.4% SD 12.4 vs 51.7%, SD 15.5; p<.05). Sympatho-vagal balance was not different in T2DM patients compared to healthy subjects. FMD and shear rate FMD did not correlate with VMR in T2DM patients or in controls (p>.05). Conclusions In well-controlled T2DM patients with short-term disease cerebral hemodynamics and systemic endothelial function are altered while autonomic balance appeared to be preserved. PMID:24391751

Goal-directed therapy improves the outcome of high-risk cardiac patients undergoing off-pump coronary artery bypass.

PubMed

Kapoor, Poonam Malhotra; Magoon, Rohan; Rawat, Rajinder Singh; Mehta, Yatin; Taneja, Sameer; Ravi, R; Hote, Milind P

2017-01-01

There has been a constant emphasis on developing management strategies to improve the outcome of high-risk cardiac patients undergoing surgical revascularization. The performance of coronary artery bypass surgery on an off-pump coronary artery bypass (OPCAB) avoids the risks associated with extra-corporeal circulation. The preliminary results of goal-directed therapy (GDT) for hemodynamic management of high-risk cardiac surgical patients are encouraging. The present study was conducted to study the outcome benefits with the combined use of GDT with OPCAB as compared to the conventional hemodynamic management. Patients with the European System for Cardiac Operative Risk Evaluation ≥3 scheduled for OPCAB were randomly divided into two groups; the control and GDT groups. The GDT group included the monitoring and optimization of advanced parameters, including cardiac index (CI), systemic vascular resistance index, oxygen delivery index, stroke volume variation; continuous central venous oxygen saturation (ScVO 2 ), global end-diastolic volume, and extravascular lung water (EVLW), using FloTrac™ , PreSep™ , and EV-1000 ® monitoring panels, in addition to the conventional hemodynamic management in the control group. The hemodynamic parameters were continuously monitored for 48 h in Intensive Care Unit (ICU) and corrected according to GDT protocol. A total of 163 patients consented for the study. Seventy-five patients were assigned to the GDT group and 88 patients were in the control group. In view of 9 exclusions from the GDT group and 12 exclusions from control group, 66 patients in the GDT group and 76 patients in control group completed the study. The length of stay in hospital (LOS-H) (7.42 ± 1.48 vs. 5.61 ± 1.11 days, P < 0.001) and ICU stay (4.2 ± 0.82 vs. 2.53 ± 0.56 days, P < 0.001) were significantly lower in the GDT group as compared to control group. The duration of inotropes (3.24 ± 0.73 vs. 2.89 ± 0.68 h, P = 0.005) was also significantly lower in the GDT group. The two groups did not differ in duration of ventilated hours, mortality, and other complications. The parameters such as ScVO 2 , CI, and EVLW had a strong negative and positive correlation with the LOS-H with r values of - 0.331, -0.319, and 0.798, respectively. The study elucidates the role of a goal-directed hemodynamic optimization for improved outcome in high-risk cardiac patients undergoing OPCAB.

Device specific analysis of neonatal aortic outflow cannula jet flows for improved cardiopulmonary bypass hemodynamics

NASA Astrophysics Data System (ADS)

Menon, Prahlad; Sotiropoulos, Fotis; Undar, Akif; Pekkan, Kerem

2011-11-01

Hemodynamically efficient aortic outflow cannulae can provide high blood volume flow rates at low exit force during extracorporeal circulation in pediatric or neonatal cardiopulmonary bypass repairs. Furthermore, optimal hemolytic aortic insertion configurations can significantly reduce risk of post-surgical neurological complications and developmental defects in the young patient. The methodology and results presented in this study serve as a baseline for design of superior aortic outflow cannulae based on a novel paradigm of characterizing jet-flows at different flow regimes. In-silico evaluations of multiple cannula tips were used to delineate baseline hemodynamic performance of the popular pediatric cannula tips in an experimental cuboidal test-rig, using PIV. High resolution CFD jet-flow simulations performed for various cannula tips in the cuboidal test-rig as well as in-vivo insertion configurations have suggested the existence of optimal surgically relevant characteristics such as cannula outflow angle and insertion depth for improved hemodynamic performance during surgery. Improved cannula tips were designed with internal flow-control features for decreased blood damage and increased permissible flow rates.

Comparing GlideScope Video Laryngoscope and Macintosh Laryngoscope Regarding Hemodynamic Responses During Orotracheal Intubation: A Randomized Controlled Trial

PubMed Central

Pournajafian, Ali Reza; Ghodraty, Mohammad Reza; Faiz, Seyed Hamid Reza; Rahimzadeh, Poupak; Goodarzynejad, Hamidreza; Dogmehchi, Enseyeh

2014-01-01

Background: To determine if the GlideScope® videolaryngoscope (GVL) could attenuate the hemodynamic responses to orotracheal intubation compared with conventional Macintosh laryngoscope. Objectives: The aim of this relatively large randomized trial was to compare the hemodynamic stress responses during laryngoscopy and tracheal intubation using GVL versus MCL amongst healthy adult individuals receiving general anesthesia for elective surgeries. Patients and Methods: Ninety five healthy adult patients with American Society of Anesthesiologists physical status class I or II that were scheduled for elective surgery under general anesthesia were randomly allocated to either Macintosh or GlideScope arms. All patients received a standardized protocol of general anesthesia. Hemodynamic changes associated with intubation were recorded before and at 1, 3 and 5 minutes after the intubation. The time taken to perform endotracheal intubation was also noted in both groups. Results: Immediately before laryngoscopy (pre-laryngoscopy), the values of all hemodynamic variables did not differ significantly between the two groups (All P values > 0.05). Blood pressures and HR values changed significantly over time within the groups. Time to intubation was significantly longer in the GlideScope (15.9 ± 6.7 seconds) than in the Macintosh group (7.8 ± 3.7 sec) (P< 0.001). However, there were no significant differences between the two groups in hemodynamic responses at all time points. Conclusions: The longer intubation time using GVL suggests that the benefit of GVL could become apparent if the time taken for orotracheal intubation could be decreased in GlideScope group. PMID:24910788

Intrathoracic leak after an Ivor Lewis procedure for an esophageal neoplasm treated with a stent.

PubMed

Afonso Luis, Natalia; Acosta Mérida, María Asunción; Marchena Gómez, Joaquín

2018-04-01

A 75-year-old male who underwent an Ivor Lewis esophagectomy due to a distal adenocarcinoma had a leak at the gastroplasty on the 5th day after surgery, which required two surgeries and a primary suture. He was transferred to our hospital due to a poor outcome and endoscopy revealed a 2.5cm gap perianastomotically on the gastroplasty wall, for which a stent was placed. Due to hemodynamic impairment, a thoracotomy procedure was performed, which revealed stent protrusion into the cavity. The patient underwent an esophagogastric anastomosis resection, cervical esophagostomy and gastrostomy. Sepsis was resolved postoperatively and the patient had a protracted stay in the PACU due to poor respiratory dynamics following a prolonged intubation.

Central hemodynamics and arterial stiffness in idiopathic and multiple system atrophy.

PubMed

Franzen, Klaas; Fliegen, Sabine; Koester, Jelena; Martin, Rafael Campos; Deuschl, Günther; Reppel, Michael; Mortensen, Kai; Schneider, Susanne A

2017-02-01

Blood pressure is commonly abnormal in parkinsonian disorders, but central hemodynamics and arterial stiffness, well-established predictors of total cardiovascular risk, have rarely been studied in these disorders. 32 patients [27 with idiopathic Parkinson's disease (iPD); 5 with multiple system atrophy (MSA)] and 15 controls matched for cardiac risk factors underwent 24 h-ambulatory blood pressure recordings using an I.E.M. device (Mobil-O-Graph™), measuring peripheral pressure and calculating central pressures and arterial stiffness. Mean augmentation indices corrected for heart rate (AIx@75) were significantly lower and pulse wave velocities were significantly elevated in patients compared to controls. Central systolic blood pressure, cardiac output and daytime total vascular resistance were significantly elevated in patients. Mean nocturnal systolic peripheral blood pressure and nocturnal heart rates were also significantly higher; 56.3% of patients had nocturnal hypertension (80% of the MSA group); 85.2% showed non-dipping. This supports previous findings of reduced vulnerability to systemic atherosclerosis and end-organ damage in treated PD. Yet, hemodynamic abnormalities were common and often remained asymptomatic.

Human Auditory and Adjacent Nonauditory Cerebral Cortices Are Hypermetabolic in Tinnitus as Measured by Functional Near-Infrared Spectroscopy (fNIRS)

PubMed Central

Issa, Mohamad; Bisconti, Silvia; Kovelman, Ioulia; Kileny, Paul

2016-01-01

Tinnitus is the phantom perception of sound in the absence of an acoustic stimulus. To date, the purported neural correlates of tinnitus from animal models have not been adequately characterized with translational technology in the human brain. The aim of the present study was to measure changes in oxy-hemoglobin concentration from regions of interest (ROI; auditory cortex) and non-ROI (adjacent nonauditory cortices) during auditory stimulation and silence in participants with subjective tinnitus appreciated equally in both ears and in nontinnitus controls using functional near-infrared spectroscopy (fNIRS). Control and tinnitus participants with normal/near-normal hearing were tested during a passive auditory task. Hemodynamic activity was monitored over ROI and non-ROI under episodic periods of auditory stimulation with 750 or 8000 Hz tones, broadband noise, and silence. During periods of silence, tinnitus participants maintained increased hemodynamic responses in ROI, while a significant deactivation was seen in controls. Interestingly, non-ROI activity was also increased in the tinnitus group as compared to controls during silence. The present results demonstrate that both auditory and select nonauditory cortices have elevated hemodynamic activity in participants with tinnitus in the absence of an external auditory stimulus, a finding that may reflect basic science neural correlates of tinnitus that ultimately contribute to phantom sound perception. PMID:27042360

Nonlinear extension of a hemodynamic linear model for coherent hemodynamics spectroscopy.

PubMed

Sassaroli, Angelo; Kainerstorfer, Jana M; Fantini, Sergio

2016-01-21

In this work, we are proposing an extension of a recent hemodynamic model (Fantini, 2014a), which was developed within the framework of a novel approach to the study of tissue hemodynamics, named coherent hemodynamics spectroscopy (CHS). The previous hemodynamic model, from a signal processing viewpoint, treats the tissue microvasculature as a linear time-invariant system, and considers changes of blood volume, capillary blood flow velocity and the rate of oxygen diffusion as inputs, and the changes of oxy-, deoxy-, and total hemoglobin concentrations (measured in near infrared spectroscopy) as outputs. The model has been used also as a forward solver in an inversion procedure to retrieve quantitative parameters that assess physiological and biological processes such as microcirculation, cerebral autoregulation, tissue metabolic rate of oxygen, and oxygen extraction fraction. Within the assumption of "small" capillary blood flow velocity oscillations the model showed that the capillary and venous compartments "respond" to this input as low pass filters, characterized by two distinct impulse response functions. In this work, we do not make the assumption of "small" perturbations of capillary blood flow velocity by solving without approximations the partial differential equation that governs the spatio-temporal behavior of hemoglobin saturation in capillary and venous blood. Preliminary comparison between the linear time-invariant model and the extended model (here identified as nonlinear model) are shown for the relevant parameters measured in CHS as a function of the oscillation frequency (CHS spectra). We have found that for capillary blood flow velocity oscillations with amplitudes up to 10% of the baseline value (which reflect typical scenarios in CHS), the discrepancies between CHS spectra obtained with the linear and nonlinear models are negligible. For larger oscillations (~50%) the linear and nonlinear models yield CHS spectra with differences within typical experimental errors, but further investigation is needed to assess the effect of these differences. Flow oscillations larger than 10-20% are not typically induced in CHS; therefore, the results presented in this work indicate that a linear hemodynamic model, combined with a method to elicit controlled hemodynamic oscillations (as done for CHS), is appropriate for the quantitative assessment of cerebral microcirculation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of extra-corporeal shock waves on penile hemodynamics and histopathology in rats.

PubMed

Tefekli, Ahmet; Armagan, Abdullah; Erol, Bulent; Celtik, Murat; Kilicaslan, Isi; Nurten, Asiye; Kadioglu, Ates

2002-12-01

To study the effect of extra-corporeal shock wave (ESW) on the penile hemodynamics and histopathology in rats. Adult male Sprague-Dawley rats were divided at random into 3 groups. ESW application was performed with a Siemens Lithostar with the rats under anesthesia lying prone on the balloon probe. Rats in Group I received a total of 1000 shocks at 18 kV and immediately underwent hemodynamic evaluation performed by direct electrostimulation of the cavernous nerve and measurement of intracavernous pressure (ICP). Rats in Group II received 3 times 1000 shocks at 18 kV at weekly intervals and hemodynamic evaluation was performed 1 month after the last ESW application. Group III served as the control. Histopathological examinations of penile tissues were done on Masson's trichrome and hematoxylin and eosin stained sections. Penile hemodynamic evaluation showed a trend toward a diminished mean maximal ICP, duration of erection, ICP during the plateau phase and maximal ICP/ blood pressure ratio in Group I, although there was no significant significance. The mean latency period in Groups I and II was prolonged. Petechial bleeding within tunical layers and small foci of hemorrhage within the corpora cavernosa were observed in Group I. However, histopathological examination failed to reveal any significant differences between the groups in terms of smooth muscle content, tunical thickness, organization of collagen bundles and elastic fiber-lattice framework. ESW has certain damaging effects on the penis.

Prenatal stress and hemodynamics in pregnancy: a systematic review.

PubMed

Levine, Terri A; Alderdice, Fiona A; Grunau, Ruth E; McAuliffe, Fionnuala M

2016-10-01

Maternal prenatal stress is associated with preterm birth, intrauterine growth restriction, and developmental delay. However, the impact of prenatal stress on hemodynamics during pregnancy remains unclear. This systematic review was conducted in order to assess the quality of the evidence available to date regarding the relationship between prenatal stress and maternal-fetal hemodynamics. The PubMed/Medline, EMBASE, PsycINFO, Maternity and Infant Care, Trip, Cochrane Library, and CINAHL databases were searched using the search terms pregnancy; stress; fetus; blood; Doppler; ultrasound. Studies were eligible for inclusion if prenatal stress was assessed with standardized measures, hemodynamics was measured with Doppler ultrasound, and methods were adequately described. A specifically designed data extraction form was used. The methodological quality of included studies was assessed using well-accepted quality appraisal guidelines. Of 2532 studies reviewed, 12 met the criteria for inclusion. Six reported that prenatal stress significantly affects maternal or fetal hemodynamics; six found no significant association between maternal stress and circulation. Significant relationships between prenatal stress and uterine artery resistance (RI) and pulsatility (PI) indices, umbilical artery RI, PI, and systolic/diastolic ratio, fetal middle cerebral artery PI, cerebroplacental ratio, and umbilical vein volume blood flow were found. To date, there is limited evidence that prenatal stress is associated with changes in circulation. More carefully designed studies with larger sample sizes, repeated assessments across gestation, tighter control for confounding factors, and measures of pregnancy-specific stress will clarify this relationship.

Pre-clinical longitudinal monitoring of hemodynamic response to anti-vascular chemotherapy by hybrid diffuse optics.

PubMed

Farzam, Parisa; Johansson, Johannes; Mireles, Miguel; Jiménez-Valerio, Gabriela; Martínez-Lozano, Mar; Choe, Regine; Casanovas, Oriol; Durduran, Turgut

2017-05-01

The longitudinal effect of an anti-vascular endothelial growth factor receptor 2 (VEGFR-2) antibody (DC 101) therapy on a xenografted renal cell carcinoma (RCC) mouse model was monitored using hybrid diffuse optics. Two groups of immunosuppressed male nude mice (seven treated, seven controls) were measured. Tumor microvascular blood flow, total hemoglobin concentration and blood oxygenation were investigated as potential biomarkers for the monitoring of the therapy effect twice a week and were related to the final treatment outcome. These hemodynamic biomarkers have shown a clear differentiation between two groups by day four. Moreover, we have observed that pre-treatment values and early changes in hemodynamics are highly correlated with the therapeutic outcome demonstrating the potential of diffuse optics to predict the therapy response at an early time point.

Hemodynamics of speech production: An fNIRS investigation of children who stutter.

PubMed

Walsh, B; Tian, F; Tourville, J A; Yücel, M A; Kuczek, T; Bostian, A J

2017-06-22

Stuttering affects nearly 1% of the population worldwide and often has life-altering negative consequences, including poorer mental health and emotional well-being, and reduced educational and employment achievements. Over two decades of neuroimaging research reveals clear anatomical and physiological differences in the speech neural networks of adults who stutter. However, there have been few neurophysiological investigations of speech production in children who stutter. Using functional near-infrared spectroscopy (fNIRS), we examined hemodynamic responses over neural regions integral to fluent speech production including inferior frontal gyrus, premotor cortex, and superior temporal gyrus during a picture description task. Thirty-two children (16 stuttering and 16 controls) aged 7-11 years participated in the study. We found distinctly different speech-related hemodynamic responses in the group of children who stutter compared to the control group. Whereas controls showed significant activation over left dorsal inferior frontal gyrus and left premotor cortex, children who stutter exhibited deactivation over these left hemisphere regions. This investigation of neural activation during natural, connected speech production in children who stutter demonstrates that in childhood stuttering, atypical functional organization for speech production is present and suggests promise for the use of fNIRS during natural speech production in future research with typical and atypical child populations.

Force related hemodynamic responses during execution and imagery of a hand grip task: A functional near infrared spectroscopy study.

PubMed

Wriessnegger, Selina C; Kirchmeyr, Daniela; Bauernfeind, Günther; Müller-Putz, Gernot R

2017-10-01

We examined force related hemodynamic changes during the performance of a motor execution (ME) and motor imagery (MI) task by means of multichannel functional near infrared spectroscopy (fNIRS). The hemodynamic responses of fourteen healthy participants were measured while they performed a hand grip execution or imagery task with low and high grip forces. We found an overall higher increase of [oxy-Hb] concentration changes during ME for both grip forces but with a delayed peak maximum for the lower grip force. During the MI task with lower grip force, the [oxy-Hb] level increases are stronger compared to the MI with higher grip force. The facilitation in performing MI with higher grip strength might thus indicate less inhibition of the actual motor act which could also explain the later increase onset of [oxy-Hb] in the ME task with the lower grip force. Our results suggest that execution and imagery of a hand grip task with high and low grip forces, leads to different cortical activation patterns. Since impaired control of grip forces during object manipulation in particular is one aspect of fine motor control deficits after stroke, our study will contribute to future rehabilitation programs enhancing patient's grip force control. Copyright © 2017 Elsevier Inc. All rights reserved.

Implementation of a post-cardiac arrest care bundle including therapeutic hypothermia and hemodynamic optimization in comatose patients with return of spontaneous circulation after out-of-hospital cardiac arrest: a feasibility study.

PubMed

Walters, Elizabeth Lea; Morawski, Kyle; Dorotta, Ihab; Ramsingh, Davinder; Lumen, Kelly; Bland, David; Clem, Kathleen; Nguyen, H Bryant

2011-04-01

Patients who present to the emergency department (ED) with return of spontaneous circulation after cardiac arrest generally have poor outcomes. Guidelines for treatment can be complicated and difficult to implement. This study examined the feasibility of implementing a care bundle including therapeutic hypothermia (TH) and early hemodynamic optimization for comatose patients with return of spontaneous circulation after out-of-hospital cardiac arrest. The study included patients over a 2-year period in the ED and intensive care unit of an academic tertiary-care medical center. The first year (prebundle) provided a historical control, followed by a prospective observational period of bundle implementation during the second year. The bundle elements included (a) TH initiated; (b) central venous pressure/central venous oxygen saturation monitoring in 2 h; (c) target temperature in 4 h; (d) central venous pressure greater than 12 mmHg in 6 h; (e) MAP greater than 65 mmHg in 6 h; (f) central venous oxygen saturation greater than 70% in 6 h; (g) TH maintained for 24 h; and (h) decreasing lactate in 24 h. Fifty-five patients were enrolled, 26 patients in the prebundle phase and 29 patients in the bundle phase. Seventy-seven percent of bundle elements were completed during the bundle phase. In-hospital mortality in bundle compared with prebundle patients was 55.2% vs. 69.2% (P = 0.29). In the bundle patients, those patients who received all elements of the care bundle had mortality 33.3% compared with 60.9% in those receiving some of the bundle elements (P = 0.22). Bundle patients tended to achieve good neurologic outcome compared with prebundle patients, Cerebral Performance Category 1 or 2 in 31 vs. 12% patients, respectively (P = 0.08). Our study demonstrated that a post-cardiac arrest care bundle that incorporates TH and early hemodynamic optimization can be implemented in the ED and intensive care unit collaboratively and can achieve similar clinical benefits compared with those observed in previous clinical trials.

Hemodynamic flow improves rat hepatocyte morphology, function, and metabolic activity in vitro.

PubMed

Dash, A; Simmers, M B; Deering, T G; Berry, D J; Feaver, R E; Hastings, N E; Pruett, T L; LeCluyse, E L; Blackman, B R; Wamhoff, B R

2013-06-01

In vitro primary hepatocyte systems typically elicit drug induction and toxicity responses at concentrations much higher than corresponding in vivo or clinical plasma C(max) levels, contributing to poor in vitro-in vivo correlations. This may be partly due to the absence of physiological parameters that maintain metabolic phenotype in vivo. We hypothesized that restoring hemodynamics and media transport would improve hepatocyte architecture and metabolic function in vitro compared with nonflow cultures. Rat hepatocytes were cultured for 2 wk either in nonflow collagen gel sandwiches with 48-h media changes or under controlled hemodynamics mimicking sinusoidal circulation within a perfused Transwell device. Phenotypic, functional, and metabolic parameters were assessed at multiple times. Hepatocytes in the devices exhibited polarized morphology, retention of differentiation markers [E-cadherin and hepatocyte nuclear factor-4α (HNF-4α)], the canalicular transporter [multidrug-resistant protein-2 (Mrp-2)], and significantly higher levels of liver function compared with nonflow cultures over 2 wk (albumin ~4-fold and urea ~5-fold). Gene expression of cytochrome P450 (CYP) enzymes was significantly higher (fold increase over nonflow: CYP1A1: 53.5 ± 10.3; CYP1A2: 64.0 ± 15.1; CYP2B1: 15.2 ± 2.9; CYP2B2: 2.7 ± 0.8; CYP3A2: 4.0 ± 1.4) and translated to significantly higher basal enzyme activity (device vs. nonflow: CYP1A: 6.26 ± 2.41 vs. 0.42 ± 0.015; CYP1B: 3.47 ± 1.66 vs. 0.4 ± 0.09; CYP3A: 11.65 ± 4.70 vs. 2.43 ± 0.56) while retaining inducibility by 3-methylcholanthrene and dexamethasone (fold increase over DMSO: CYP1A = 27.33 and CYP3A = 4.94). These responses were observed at concentrations closer to plasma levels documented in vivo in rats. The retention of in vivo-like hepatocyte phenotype and metabolic function coupled with drug response at more physiological concentrations emphasizes the importance of restoring in vivo physiological transport parameters in vitro.

Increased variability of watershed areas in patients with high-grade carotid stenosis.

PubMed

Kaczmarz, Stephan; Griese, Vanessa; Preibisch, Christine; Kallmayer, Michael; Helle, Michael; Wustrow, Isabel; Petersen, Esben Thade; Eckstein, Hans-Henning; Zimmer, Claus; Sorg, Christian; Göttler, Jens

2018-03-01

Watershed areas (WSAs) of the brain are most susceptible to acute hypoperfusion due to their peripheral location between vascular territories. Additionally, chronic WSA-related vascular processes underlie cognitive decline especially in patients with cerebral hemodynamic compromise. Despite of high relevance for both clinical diagnostics and research, individual in vivo WSA definition is fairly limited to date. Thus, this study proposes a standardized segmentation approach to delineate individual WSAs by use of time-to-peak (TTP) maps and investigates spatial variability of individual WSAs. We defined individual watershed masks based on relative TTP increases in 30 healthy elderly persons and 28 patients with unilateral, high-grade carotid stenosis, being at risk for watershed-related hemodynamic impairment. Determined WSA location was confirmed by an arterial transit time atlas and individual super-selective arterial spin labeling. We compared spatial variability of WSA probability maps between groups and assessed TTP differences between hemispheres in individual and group-average watershed locations. Patients showed significantly higher spatial variability of WSAs than healthy controls. Perfusion on the side of the stenosis was delayed within individual watershed masks as compared to a watershed template derived from controls, being independent from the grade of the stenosis and collateralization status of the circle of Willis. Results demonstrate feasibility of individual WSA delineation by TTP maps in healthy elderly and carotid stenosis patients. Data indicate necessity of individual segmentation approaches especially in patients with hemodynamic compromise to detect critical regions of impaired hemodynamics.

Which one is more effective for analgesia in infratentorial craniotomy? The scalp block or local anesthetic infiltration.

PubMed

Akcil, Eren Fatma; Dilmen, Ozlem Korkmaz; Vehid, Hayriye; Ibısoglu, Lutfiye Serap; Tunali, Yusuf

2017-03-01

The most painful stages of craniotomy are the placement of the pin head holder and the skin incision. The primary aim of the present study is to compare the effects of the scalp block and the local anesthetic infiltration with bupivacaine 0.5% on the hemodynamic response during the pin head holder application and the skin incision in infratentorial craniotomies. The secondary aims are the effects on pain scores and morphine consumption during the postoperative 24h. This prospective, randomized and placebo controlled study included forty seven patients (ASA I, II and III). The scalp block was performed in the Group S, the local anesthetic infiltration was performed in the Group I and the control group (Group C) only received remifentanil as an analgesic during the intraoperative period. The hemodynamic response to the pin head holder application and the skin incision, as well as postoperative pain intensity, cumulative morphine consumption and opioid related side effects were compared. The scalp block reduced the hemodynamic response to the pin head holder application and the skin incision in infratentorial craniotomies. The local anesthetic infiltration reduced the hemodynamic response to the skin incision. As well as both scalp block and local anesthetic infiltration reduced the cumulative morphine consumption in postoperative 24h. Moreover, the pain intensity was lower after scalp block in the early postoperative period. The scalp block may provide better analgesia in infratentorial craniotomies than local anesthetic infiltration. Copyright © 2017 Elsevier B.V. All rights reserved.

Temazepam, but not zolpidem, causes orthostatic hypotension in astronauts after spaceflight

NASA Technical Reports Server (NTRS)

Shi, Shang-Jin; Garcia, Kathleen M.; Meck, Janice V.

2003-01-01

Insomnia is a common symptom, not only in the adult population but also in many astronauts. Hypnotics, such as temazepam (a benzodiazepine) and zolpidem (an imidazopyridine), are often taken to relieve insomnia. Temazepam has been shown clinically to have hemodynamic side effects, particularly in the elderly; however, the mechanism is not clear. Zolpidem does not cause hemodynamic side effects. The purpose of this study was to determine whether the use of different hypnotics during spaceflight might contribute significantly to the high incidence of postflight orthostatic hypotension, and to compare the findings in astronauts with clinical research. Astronauts were separated into three groups: control (n = 40), temazepam (15 or 30 mg; n = 9), and zolpidem (5 or 10 mg; n = 8). In this study, temazepam and zolpidem were only taken the night before landing. The systolic and diastolic blood pressures and heart rates of the astronauts were measured during stand tests before spaceflight and on landing day. On landing day, systolic pressure decreased significantly and heart rate increased significantly in the temazepam group, but not in the control group or in the zolpidem group. Temazepam may aggravate orthostatic hypotension after spaceflight when astronauts are hemodynamically compromised. Temazepam should not be the initial choice as a sleeping aid for astronauts. These results in astronauts may help to explain the hemodynamic side effects in the elderly who are also compromised. Zolpidem may be a better choice as a sleeping aid in these populations.

Antibody and complement reduce renal hemodynamic function in isolated perfused rat kidney.

PubMed

Jocks, T; Zahner, G; Helmchen, U; Kneissler, U; Stahl, R A

1996-01-01

To evaluate the effect of antibody and complement on renal hemodynamic changes, glomerular injury was induced in isolated perfused kidneys by an anti-thymocyte antibody (ATS) and rat serum (RS). Glomerular filtration rate (GFR), renal vascular resistance (RVR), and renal perfusate flow (RPF) were assessed over an 80-min period. The possible role of thromboxane (Tx) was tested by the application of the Tx synthesis inhibitor UK-38485 and the Tx receptor blocker daltroban. Perfusion of kidneys with ATS and RS significantly reduced GFR at 10 min (control, 501 +/- 111; ATS + RS, 138 +/- 86 ml.g kidney-1.min-1, significance of F = 0.000) after RS. Similarly, RPF (ml.g kidney-1.min-1) fell from 19.2 +/- 1.8 to 6.1 +/- 2.0 (significance of F = 0.000), whereas RVR (mmHg.ml-1.g.min) increased threefold from 5.2 +/- 0.4 to 17.9 +/- 5.0 at 10 min. These changes were ameliorated by the pretreatment of the rats with daltroban and UK-38485. Addition of erythrocytes to the perfusate increased RVR and GFR, whereas RPF decreased compared with cell-free perfused kidneys. ATS and RS in this preparation also decrease GFR and RPF. The hemodynamic alterations appeared without changes in filtration fraction. Compared with untreated, perfused control kidneys, glomerular Tx formation was significantly increased in ATS and RS perfused kidneys. These data demonstrate that antibody and RS induce impairment of renal hemodynamics, which are mediated by increased Tx formation.

Baseline Hemodynamics and Response to Contrast Media During Diagnostic Cardiac Catheterization Predict Adverse Events in Heart Failure Patients.

PubMed

Denardo, Scott J; Vock, David M; Schmalfuss, Carsten M; Young, Gregory D; Tcheng, James E; O'Connor, Christopher M

2016-07-01

Contrast media administered during cardiac catheterization can affect hemodynamic variables. However, little is documented about the effects of contrast on hemodynamics in heart failure patients or the prognostic value of baseline and changes in hemodynamics for predicting subsequent adverse events. In this prospective study of 150 heart failure patients, we measured hemodynamics at baseline and after administration of iodixanol or iopamidol contrast. One-year Kaplan-Meier estimates of adverse event-free survival (death, heart failure hospitalization, and rehospitalization) were generated, grouping patients by baseline measures of pulmonary capillary wedge pressure (PCWP) and cardiac index (CI), and by changes in those measures after contrast administration. We used Cox proportional hazards modeling to assess sequentially adding baseline PCWP and change in CI to 5 validated risk models (Seattle Heart Failure Score, ESCAPE [Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness], CHARM [Candesartan in Heart Failure: Assessment of Reduction in Mortality and Morbidity], CORONA [Controlled Rosuvastatin Multinational Trial in Heart Failure], and MAGGIC [Meta-Analysis Global Group in Chronic Heart Failure]). Median contrast volume was 109 mL. Both contrast media caused similarly small but statistically significant changes in most hemodynamic variables. There were 39 adverse events (26.0%). Adverse event rates increased using the composite metric of baseline PCWP and change in CI (P<0.01); elevated baseline PCWP and decreased CI after contrast correlated with the poorest prognosis. Adding both baseline PCWP and change in CI to the 5 risk models universally improved their predictive value (P≤0.02). In heart failure patients, the administration of contrast causes small but significant changes in hemodynamics. Calculating baseline PCWP with change in CI after contrast predicts adverse events and increases the predictive value of existing models. Patients with elevated baseline PCWP and decreased CI after contrast merit greatest concern. © 2016 American Heart Association, Inc.

Effects of antihypertensive drugs on central blood pressure in humans: a preliminary observation.

PubMed

Agnoletti, Davide; Zhang, Yi; Borghi, Claudio; Blacher, Jacques; Safar, Michel E

2013-08-01

Central blood pressure (BP) is considered a better predictor of cardiovascular events than brachial BP. Modifications of central, beyond brachial BP, can be assessed by pressure amplification, a potential new cardiovascular risk factor. Comparison between drugs' effect on central hemodynamics has been poorly studied. Our aim was to assess the hemodynamic effect of a 12-week treatment with amlodipine 5mg, or candesartan 8mg, or indapamide sustained-release 1.5mg, in comparison with placebo. We analyzed 145 out-patients with essential hypertension in primary prevention enrolled in the Natrilix SR Versus Candesartan and Amlodipine in the Reduction of Systolic Blood Pressure in Hypertensive Patients (X-CELLENT) study, a multicenter, randomized, double-blinded, placebo-controlled trial. Arterial stiffness, central BP, pressure amplification, and wave reflection were measured by applanation tonometry. Baseline characteristics of patients were homogeneous between groups. After treatment, we found that active drugs produced similar reduction of both central and peripheral BPs, with no significant interdrug differences (all P < 0.05; excluded peripheral pulse pressure, compared with placebo). Second, amlodipine (1.9% ± 15.3%), candesartan (3.0% ± 14.6%) and indapamide (4.1% ± 14.4%) all increased pulse pressure amplification, but only indapamide was statistically different from placebo (P = 0.02). Finally, no significant changes were observed on pulse wave velocity, heart rate, and augmentation index. The 3 antihypertensive drugs similarly reduced peripheral and central BP, as compared with placebo, but a significant increase in pulse pressure amplification was obtained only with indapamide, independently of arterial stiffness modifications. 3283161 by BIOPHARMA.

Comparison of fluid balance and hemodynamic and metabolic effects of sodium lactate versus sodium bicarbonate versus 0.9% NaCl in porcine endotoxic shock: a randomized, open-label, controlled study.

PubMed

Duburcq, Thibault; Durand, Arthur; Dessein, Anne-Frédérique; Vamecq, Joseph; Vienne, Jean-Claude; Dobbelaere, Dries; Mention, Karine; Douillard, Claire; Maboudou, Patrice; Gmyr, Valery; Pattou, François; Jourdain, Mercé; Tamion, Fabienne; Poissy, Julien; Mathieu, Daniel; Favory, Raphaël

2017-05-19

Sodium lactate has been shown to improve hemodynamics and avoid fluid overload. The objective of this study was to confirm a beneficial effect on fluid balance with sodium lactate infusion and to specify whether the advantage of lactate is related to a negative chloride balance, its particular metabolism, or simply its energy load. This was an interventional, randomized, open-label, controlled experimental study. Fifteen female "large white" pigs (2 months old) were challenged with intravenous infusion of Escherichia coli endotoxin. Three groups of five animals were randomly assigned to receive different fluids: a treatment group received sodium lactate 11.2% (SL group); an isotonic control group received 0.9% NaCl (NC group); and a hypertonic control group, with the same amount of osmoles and sodium as the SL group, received sodium bicarbonate 8.4% (SB group). In order to provide the same energy load in the three groups, control groups were perfused with an equivalent energy supply. Statistical analysis was performed with non-parametric tests and the Dunn correction for multiple comparisons at p < 0.05. Fluid and chloride balance, hemodynamics, oxygenation markers, and microcirculatory parameters were measured over a 5-h period. Cumulative fluid balance was significantly lower in the SL group (550 (415-800) mL; median (interquartile range)) compared to the NC group (1100 (920-1640) mL, p = 0.01) and the SB group (935 (790-1220) mL, p = 0.03). Hemodynamics, cardiac efficiency, and microcirculation were significantly enhanced in the SL group, resulting in a significant improvement in oxygen delivery (SL group 417 (305-565) mL/min/m 2 at 300 min versus the NC (207 (119-272) mL/min/m 2 , p = 0.01) and the SB (278, (211-315) mL/min/m 2 , p = 0.03) groups). Oxygenation markers (arterial oxygen partial pressure (PaO 2 )/inspired oxygen fraction (FiO 2 ), mixed venous oxygen saturation (SvO 2 ), and venoarterial carbon dioxide tension difference (Pv-aCO 2 ) were enhanced with sodium lactate infusion. Chloride balance was equivalent in both hypertonic groups and significantly reduced compared to the NC group. Sodium lactate infusion improves fluid balance and hemodynamics. The advantage of lactate does not seem to be explained by its energy load or by the induced negative chloride balance with subsequent water movements.

[Effect of Transcutaneous Acupoint Electrical Stimulation on Hemodynamic Fluctuation Caused by Loosing Tourniquet in Elderly Patients Undergoing Knee Joint Replacement].

PubMed

Liang, Han-Sheng; Feng, Yi

2017-12-25

To observe the effect of transcutaneous acupoint electrical stimulation (TAES) on hemodynamic fluctuation caused by loosing tourniquet in the elderly patients undergoing knee joint replacement. A total of 60 ASA (America Society Anesthesiologist) I or II elderly patients for elective knee joint replacement surgery were randomly divided into control group (30 cases) and TAES group (30 cases). Patients of both groups were treated by intravenous anesthesia, and monitored with bispectral index (BIS, between 45－60) for anesthesia depth, stroke volume variation (SVV) for fluid management, mean arterial pressure (MAP) and cardiac index (CI) for hemodynamic fluctuation evaluation, and with analgesia nociception index (ANI, between 50－70) for remifentanil dosage adjustment. TAES (2 Hz/100 Hz, 8－20 mA) was applied to bilateral Xinshu (BL 15), Feishu (BL 13), Neiguan (PC 6) and Hegu (LI 4) acupoints for 30 min first (followed by anesthesia induction and operation), and given continuously until 15 min after tourniquet loosing. Patients of the control group were only given with electrodes attachment without electrical stimulation. The levels of MAP, CI, and arterial blood pH, PaCO 2 , PaO 2 , base excess (BE) and lactic acid (Lac) 1 min before, and 5 and 15 min after tourniquet loosing, and the dosages of remifentanil and ephedrine after tourniquet loosing were recorded. The changed levels of MAP, CI and blood Lac at 5 min after tourniquet loosing (relevant to the baseline levels), and blood Lac content at 15 min after tourniquet loosing (relevant to 5 min after tourniquet loosing) were significantly lower in the TAES group than in the control group ( P <0.05), but the levels of MAP and CI at 15 min after tourniquet loosing (relevant to 5 min following tourniquet loosing) were significantly higher in the TAES group than in the control group ( P <0.05), suggesting an improvement of blood pressure, cardiac function and substance metabolism after TAES. Moreover, the dosages of remifentanil and ephedrine after tourniquet loosing were considerably lower in the TAES group than in the control group ( P <0.05), suggesting a better stabilization of hemodynamics after TAES. No significant differences were found between the two groups in the levels of blood pH, PaCO 2 , PaO 2 and BE at 5 and 15 min after tourniquet loosing ( P >0.05). TAES has a positive effect on hemodynamics fluctuation caused by loosing tourniquet in the aged patients undergoing knee joint replacement.

Successful Retreatment of Recurrent Intracranial Vertebral Artery Dissecting Aneurysms After Stent-Assisted Coil Embolization: A Self-Controlled Hemodynamic Analysis.

PubMed

Liu, Jian; Jing, Linkai; Zhang, Ying; Song, Ying; Wang, Yang; Li, Chuanhui; Wang, Yanmin; Mu, Shiqing; Paliwal, Nikhil; Meng, Hui; Linfante, Italo; Yang, Xinjian

2017-01-01

Intracranial vertebral artery dissecting aneurysms (VADAs) tend to recur despite successful stent-assisted coil embolization (SACE). Hemodynamics is useful in evaluating aneurysmal formation, growth, and rupture. Our aim was to evaluate the hemodynamic patterns of the recurrence of VADA. Between September 2009 and November 2013, all consecutive patients with recurrent VADAs after SACE in our institutions were enrolled. Recurrence was defined as recanalization and/or regrowth. We assessed the hemodynamic alterations in wall shear stress (WSS) and velocity after the initial SACE and subsequently after retreatment of the aneurysms that recurred. Five patients were included. After the initial treatment, 3 patients showed recanalization and 2 showed regrowth. In the 2 patients with regrowth, the 2 original aneurysms maintained complete occlusion; however, de novo aneurysm regrowth was confirmed near the previous site. Compared with 3 recanalized aneurysms, the completely occluded aneurysms showed high mean reductions in velocity and WSS after initial treatment (velocity, 77.6% vs. 57.7%; WSS, 74.2% vs. 52.4%); however, WSS remained high at the region near the previous lesion where the new aneurysm originated. After the second retreatment, there was no recurrence in any patient. Compared with the 3 aneurysms that recanalized, the 4 aneurysms that maintained complete occlusion showed higher reductions in velocity (62.9%) and WSS (71.1%). Our series indicated that hemodynamics might have an important role in recurrence of VADAs. After endovascular treatment, sufficient hemodynamic reduction in aneurysm dome, orifice, and parent vessel may be one of the key factors for preventing recurrence in VADAs. Copyright © 2016 Elsevier Inc. All rights reserved.

Association between percutaneous hemodynamic support device and survival from cardiac arrest in the state of Michigan.

PubMed

Pressman, Andrew; Sawyer, Kelly N; Devlin, William; Swor, Robert

2018-05-01

The role of circulatory support in the post-cardiac arrest period remains controversial. Our objective was to investigate the association between treatment with a percutaneous hemodynamic support device and outcome after admission for cardiac arrest. We performed a retrospective study of adult patients with admission diagnosis of cardiac arrest or ventricular fibrillation (VF) from the Michigan Inpatient Database, treated between July 1, 2010, and June 30, 2013. Patient demographics, clinical characteristics, treatments, and disposition were electronically abstracted based on ICD-9 codes at the hospital level. Mixed-effects logistic regression models were fit to test the effect of percutaneous hemodynamic support device defined as either percutaneous left ventricular assist device (pLVAD) or intra-aortic balloon pump (IABP) on survival. These models controlled for age, sex, VF, myocardial infarction (MI), and cardiogenic shock with hospital modeled as a random effect. A total of 103 hospitals contributed 4393 patients for analysis, predominately male (58.8%) with a mean age of 64.1years (SD 15.5). On univariate analysis, younger age, male sex, VF as the initial rhythm, acute MI, percutaneous coronary intervention, percutaneous hemodynamic support device, and absence of cardiogenic shock were associated with survival to discharge (each p<0.001). Mixed-effects logistic regressions revealed use of percutaneous hemodynamic support device was significantly associated with survival among all patients (OR 1.8 (1.28-2.54)), and especially in those with acute MI (OR 1.95 (1.31-2.93)) or cardiogenic shock (OR 1.96 (1.29-2.98)). Treatment with percutaneous hemodynamic support device in the post-arrest period may provide left ventricular support and improve outcome. Copyright © 2017 Elsevier Inc. All rights reserved.

Ongoing right ventricular hemodynamics in heart failure: clinical value of measurements derived from an implantable monitoring system.

PubMed

Adamson, Philip B; Magalski, Anthony; Braunschweig, Frieder; Böhm, Michael; Reynolds, Dwight; Steinhaus, David; Luby, Allyson; Linde, Cecilia; Ryden, Lars; Cremers, Bodo; Takle, Teri; Bennett, Tom

2003-02-19

This study examined the characteristics of continuously measured right ventricular (RV) hemodynamic information derived from an implantable hemodynamic monitor (IHM) in heart failure patients. Hemodynamic monitoring might improve the day-to-day management of patients with chronic heart failure (CHF). Little is known about the characteristics of long-term hemodynamic information in patients with CHF or how such information relates to meaningful clinical events. Thirty-two patients with CHF received a permanent RV IHM system similar to a single-lead pacemaker. Right ventricular systolic and diastolic pressures, heart rate, and pressure derivatives were continuously measured for nine months without using the data for clinical decision-making or management of patients. Data were then made available to clinical providers, and the patients were followed up for 17 months. Pressure characteristics during optimal volume, clinically determined volume-overload exacerbations, and volume depletion events were examined. The effect of IHM on hospitalizations was examined using the patients' historical controls. Long-term RV pressure measurements had either marked variability or minimal time-related changes. During 36 volume-overload events, RV systolic pressures increased by 25 +/- 4% (p < 0.05) and heart rate increased by 11 +/- 2% (p < 0.05). Pressure increases occurred in 9 of 12 events 4 +/- 2 days before the exacerbations requiring hospitalization. Hospitalizations before using IHM data for clinical management averaged 1.08 per patient year and decreased to 0.47 per patient-year (57% reduction, p < 0.01) after hemodynamic data were used. Long-term ambulatory pressure measurements from an IHM may be helpful in guiding day-to-day clinical management, with a potentially favorable impact on CHF hospitalizations.

Is total abolishment of great saphenous reflux in the invasive treatment of superficial chronic venous insufficiency always necessary?

PubMed

Navarro, T P; Nunes, T A; Ribeiro, A L; Castro-Silva, M

2009-02-01

Chronic venous insufficiency ranges from mild telangiectasias to skin ulceration with poor prognosis regarding healing and quality of life. Varicose veins are the most frequent clinical presentation, affecting 75% of such patients and 71% are due to primary reflux of great saphenous vein, which is the most compromised vein in chronic venous insufficiency. However, about 75% of these veins are not dilated. The standard treatment has been stripping of the saphenous vein, because it has 85% of good results at long term. However, saphenous vein is the main arterial substitute and should be spared whenever possible. The development of non-invasive diagnostic methods showed that hemodynamic worsening correlates with clinical severity and that the majority of patients did not have a dilated saphenous vein. Thus, several selective operations proposed to spare the saphenous vein have reported good results. Minimally invasive techniques (eco-guided foam, radiofrequency and laser) have also emerged aiming to obliterate the vein and abolishing reflux and have also reported good results, but they do not spare the vessel. Measurement of saphenous diameter has been shown to correlate with clinical and hemodynamic worsening, thus allowing planning the invasive treatment of chronic venous insufficiency. Dilated diameters (>7.2 mm) correlate with severe disease and poor prognosis, being an indication for total abolishment of saphenous vein reflux. All other presentations must be individualized, sparing saphenous vein whenever possible and and a standardized approach is not indicated for all patients.

Physiology of breathlessness associated with pleural effusions

PubMed Central

Thomas, Rajesh; Jenkins, Susan; Eastwood, Peter R.; Lee, Y.C. Gary; Singh, Bhajan

2015-01-01

Purpose of review Pleural effusions have a major impact on the cardiorespiratory system. This article reviews the pathophysiological effects of pleural effusions and pleural drainage, their relationship with breathlessness, and highlights key knowledge gaps. Recent findings The basis for breathlessness in pleural effusions and relief following thoracentesis is not well understood. Many existing studies on the pathophysiology of breathlessness in pleural effusions are limited by small sample sizes, heterogeneous design and a lack of direct measurements of respiratory muscle function. Gas exchange worsens with pleural effusions and improves after thoracentesis. Improvements in ventilatory capacity and lung volumes following pleural drainage are small, and correlate poorly with the volume of fluid drained and the severity of breathlessness. Rather than lung compression, expansion of the chest wall, including displacement of the diaphragm, appears to be the principle mechanism by which the effusion is accommodated. Deflation of the thoracic cage and restoration of diaphragmatic function after thoracentesis may improve diaphragm effectiveness and efficiency, and this may be an important mechanism by which breathlessness improves. Effusions do not usually lead to major hemodynamic changes, but large effusions may cause cardiac tamponade and ventricular diastolic collapse. Patients with effusions can have impaired exercise capacity and poor sleep quality and efficiency. Summary Pleural effusions are associated with abnormalities in gas exchange, respiratory mechanics, respiratory muscle function and hemodynamics, but the association between these abnormalities and breathlessness remains unclear. Prospective studies should aim to identify the key mechanisms of effusion-related breathlessness and predictors of improvement following pleural drainage. PMID:25978627

Physiology of breathlessness associated with pleural effusions.

PubMed

Thomas, Rajesh; Jenkins, Susan; Eastwood, Peter R; Lee, Y C Gary; Singh, Bhajan

2015-07-01

Pleural effusions have a major impact on the cardiorespiratory system. This article reviews the pathophysiological effects of pleural effusions and pleural drainage, their relationship with breathlessness, and highlights key knowledge gaps. The basis for breathlessness in pleural effusions and relief following thoracentesis is not well understood. Many existing studies on the pathophysiology of breathlessness in pleural effusions are limited by small sample sizes, heterogeneous design and a lack of direct measurements of respiratory muscle function. Gas exchange worsens with pleural effusions and improves after thoracentesis. Improvements in ventilatory capacity and lung volumes following pleural drainage are small, and correlate poorly with the volume of fluid drained and the severity of breathlessness. Rather than lung compression, expansion of the chest wall, including displacement of the diaphragm, appears to be the principle mechanism by which the effusion is accommodated. Deflation of the thoracic cage and restoration of diaphragmatic function after thoracentesis may improve diaphragm effectiveness and efficiency, and this may be an important mechanism by which breathlessness improves. Effusions do not usually lead to major hemodynamic changes, but large effusions may cause cardiac tamponade and ventricular diastolic collapse. Patients with effusions can have impaired exercise capacity and poor sleep quality and efficiency. Pleural effusions are associated with abnormalities in gas exchange, respiratory mechanics, respiratory muscle function and hemodynamics, but the association between these abnormalities and breathlessness remains unclear. Prospective studies should aim to identify the key mechanisms of effusion-related breathlessness and predictors of improvement following pleural drainage.

Baricity of Bupivacaine on Maternal Hemodynamics after Spinal Anesthesia for Cesarean Section: A Randomized Controlled Trial

PubMed Central

Atashkhoei, Simin; Abedini, Naghi; Pourfathi, Hojjat; Znoz, Ali Bahrami; Marandi, Pouya Hatami

2017-01-01

Background: After spinal anesthesia, patients undergoing cesarean section are more likely to develop hemodynamic changes. The baricity of local anesthetic has an important role on spinal blockade effects. The aim of this study was to compare the isobar and hyperbaric bupivacaine 0.5% plus fentanyl on maternal hemodynamics after spinal anesthesia for C/S. Methods: In this double-blind study, 84 healthy pregnant women undergoing C/S using bupivacaine 0.5% isobar (study group, n=42) or hyperbaric (control group, n=42) for spinal anesthesia were scheduled. The study was conducted from 21 April 2014 to 21 November 2014 at Al-Zahra Hospital, Tabriz, Iran. Parameters such as maternal hemodynamics, block characteristics, side effects, and neonatal Apgar scores were recorded. Data were analyzed using the SPSS software by performing chi-square test, Fisher’s exact test, one-way ANOVA, Mann-Whitney U-test, and student’s t test. Results: The incidence of hypotension in the isobar group was lower than the hyperbaric group, although it was not statistically significant (40.47% vs. 61.9%, P=0.08). The duration of hypotension was shorter in the study group (1.6±7.8 min vs. 7.4±12.5 min, P=0.004). The dose of ephedrine was lower in the study group (2.4±6.6 mg vs. 5.3±10.7 mg, P=0.006). The main maternal side effect is sustained hypotension that was seen in 0 patients of the isobar and 7 (16.66%) of hyperbaric groups (P=0.006). None of the neonates had Apgar score≤7 at 5 min of delivery (P=1.0). Sensory and motor block duration was shorter in the study group (P=0.01). Conclusion: Isobaric bupivacaine is associated with more hemodynamic stability and shorter sensory and motor blockade in mothers under spinal anesthesia for C/S. Trial Registration Number: IRCT201401287013N7 PMID:28360439

Quantitative assessment of cerebral hemodynamic parameters by QUASAR arterial spin labeling in Alzheimer's disease and cognitively normal Elderly adults at 3-tesla.

PubMed

Mak, Henry K F; Chan, Queenie; Zhang, Zhipeng; Petersen, Esben T; Qiu, Deqiang; Zhang, Linda; Yau, Kelvin K W; Chu, Leung-Wing; Golay, Xavier

2012-01-01

QUASAR arterial spin labeling (ASL) was used to investigate the role of vascular impairment in Alzheimer's disease (AD). We hypothesized that the hemodynamic parameters monitoring cerebrovascular integrity, i.e., cerebral blood flow (CBF), arterial blood volume (aBV), and arterial transit time (aTT), would be affected. 13 AD patients and 15 healthy control (HC) subjects underwent 3T MRI scanning. Two separate blood flow acquisitions were obtained with 1 slice overlap for whole brain coverage. CBF, aBV, and aTT maps were calculated using in-house software. Preprocessing and statistical analyses were performed on SPM5. Region-of-interest (ROI) studies of ten selected cerebral regions were also conducted. There were significant differences in mini mental status exam (MMSE) (AD: 16.3 ± 4.55, HC: 28.5 ± 2.00) and Alzheimer's disease assessment scale-cognitive subscale (ADAS-cog) scores (AD: 25.25 ± 9.64, HC: 5.51 ± 2.62) between the 2 groups (p < 0.001) but none in age (p = 0.068). CBF decreased significantly (p < 0.01) in AD compared to controls in the right middle cingulate, left cuneus, left inferior and middle frontal, right superior frontal, left inferior parietal, and right supramarginal gyri. ROI studies confirmed significant hemodynamic impairments in AD compared to HC (p < 0.05): CBF in middle and posterior cingulate, aBV in left superior temporal, right inferior parietal, and posterior cingulate, and aTT in left inferior frontal and middle cingulate gyri. CBF correlated positively while aTT correlated negatively to MMSE, and vice versa for ADAS-cog. Using QUASAR ASL, we found patterns of regional hemodynamic impairment typical of moderate AD, suggesting underlying vascular abnormality. As potential biomarkers, these hemodynamic parameters could differentiate patients from volunteers, and possibly indicate the conversion from healthy aging to mild cognitive impairment to AD.

Predicted Hemodynamic Benefits Of Counterpulsation Therapy Using A Superficial Surgical Approach

PubMed Central

Giridharan, Guruprasad A.; Pantalos, George M.; Litwak, Kenneth N.; Spence, Paul A.; Koenig, Steven C.

2010-01-01

A volume-displacement counterpulsation device (CPD) intended for chronic implantation via a superficial surgical approach is proposed. The CPD is a pneumatically driven sac that fills during native heart systole and empties during diastole through a single, valveless cannula anastomosed to the subclavian artery. Computer simulation was performed to predict and compare the physiological responses of the CPD to the intraaortic balloon pump (IABP) in a clinically relevant model of early stage heart failure. The effect of device stroke volume (0–50 ml) and control modes (timing, duration, morphology) on landmark hemodynamic parameters and the LV pressure–volume relationship were investigated. Simulation results predicted that the CPD would provide hemodynamic benefits comparable to an IABP as evidenced by up to 25% augmentation of peak diastolic aortic pressure, which increases diastolic coronary perfusion by up to 34%. The CPD may also provide up to 34% reduction in LV end-diastolic pressure and 12% reduction in peak systolic aortic pressure, lowering LV workload by up to 26% and increasing cardiac output by up to 10%. This study demonstrated that the superficial CPD technique may be used acutely to achieve similar improvements in hemodynamic function as the IABP in early stage heart failure patients. PMID:16436889

Hemodynamic and neurohormonal responses to extreme orthostatic stress in physically fit young adults

NASA Astrophysics Data System (ADS)

Grasser, E. K.; Goswami, N.; Rössler, A.; Vrecko, K.; Hinghofer-Szalkay, H.

2009-04-01

Blood pressure stability may be jeopardized in astronauts experiencing orthostatic stress. There is disagreement about cardiovascular and endocrine stress responses that emerge when a critical (presyncopal) state is reached. We studied hemodynamic and neurohormonal changes as induced by an orthostatic stress paradigm (head-up tilt combined with lower body negative pressure) that leads to a syncopal endpoint. From supine control to presyncope, heart rate increased by 78% and thoracic impedance by 12%. There was a 49% fall in stroke volume index, 19% in mean arterial blood pressure, 14% in total peripheral resistance index and 11% in plasma volume. Plasma norepinephrine rose by 107, epinephrine by 491, plasma renin activity by 167, and cortisol by 25%. Hemodynamic and hormonal changes of clearly different magnitude emerge in presyncope as compared to supine rest. Additional studies are warranted to reveal the exact time course of orthostatic changes up to syncopal levels.

Occult constrictive pericardial disease emerging 40 years after chest radiation therapy: a case report.

PubMed

Goten, Chiaki; Murai, Hisayoshi; Takashima, Shin-Ichiro; Kato, Takeshi; Usui, Soichiro; Furusho, Hiroshi; Saeki, Takahiro; Sakagami, Satoru; Takemura, Hirofumi; Kaneko, Shuichi; Takamura, Masayuki

2018-05-31

The main etiology of constrictive pericarditis (CP) has changed from tuberculosis to therapeutic mediastinal radiation and cardiac surgery. Occult constrictive pericardial disease (OCPD) is a covert disease in which CP is manifested in a condition of volume overload. A 60-year-old patient with a history of thoracic radiation therapy for non-Hodgkin's lymphoma (40 years earlier) was transferred to our hospital for treatment of repeated congestive heart failure. For a preoperative hemodynamic study, pre-hydration with intravenous normal saline (50 mL/hour) was used to manifest the pericardial disease and prevent contrast-induced nephropathy. The hemodynamic study showed a right ventricular dip-plateau pattern and discordance of right and left ventricular systolic pressures during inspiration, which was not seen in the volume-controlled state. These responses were concordant with OCPD. A pericardiectomy, aortic valve replacement, and mitral and tricuspid valve repair were performed. Postoperatively, the heart failure was controlled with standard medication. This case revealed a volume-induced change in hemodynamics in OCPD with severe combined valvular heart disease, which suggests the importance of considering OCPD in patients who had undergone radiation therapy 40 years before.

Milrinone is preferred to levosimendan for mesenteric perfusion in hypoxia-reoxygenated newborn piglets treated with dopamine

PubMed Central

Manouchehri, Namdar; Bigam, David L.; Churchill, Thomas; Joynt, Chloe; Vento, Maximo; Cheung, Po-Yin

2016-01-01

INTRODUCTION There is little information regarding the comparative hemodynamic effects of adding milrinone or levosimendan to dopamine infusion in hypoxia-reoxygenated (H-R) newborns. RESULTS Severely hypoxic piglets had cardiogenic shock with depressed cardiac index (CI) and mean arterial pressure (MAP). The hemodynamics deteriorated gradually after initial recovery upon reoxygenation. Heart rate and CI improved with milrinone (D+M) and levosimendan (D+L) administration (P < 0.05 vs. control). Both regimens improved carotid arterial flow and carotid vascular resistance; D+M additionally improved superior mesentric arterial flow (all P < 0.05 vs. control). No effect was found on renal arterial flow or elevated lactate state with either regimen. D+M piglets also had a lower myocardial oxidized/reduced glutathione ratio (P < 0.05 vs. control). DISCUSSION In conclusion, adding milrinone or levosimendan to dopamine similarly improved systemic hemodynamics in H-R newborn piglets. Milrinone also improved mesenteric perfusion and attenuated myocardial oxidative stress. METHODS Twenty-eight piglets (1–4 d, 1.5–2.5 kg) were instrumented for continuous monitoring of systemic MAP and pulmonary arterial pressure (PAP), CI, and carotid, superior mesenteric, and renal arterial flows. Piglets were randomized with blinding to sham-operated, H-R control (saline), and H-R dopamine (10 μg/kg/min) with D+M or D+L groups. H-R piglets underwent H-R followed by 2 h of drug infusion after reoxygenation. Tissue was collected for biochemical/oxidative stress testing and histological analysis. PMID:22337258

Milrinone is preferred to levosimendan for mesenteric perfusion in hypoxia-reoxygenated newborn piglets treated with dopamine.

PubMed

Manouchehri, Namdar; Bigam, David L; Churchill, Thomas; Joynt, Chloe; Vento, Maximo; Cheung, Po-Yin

2012-03-01

There is little information regarding the comparative hemodynamic effects of adding milrinone or levosimendan to dopamine infusion in hypoxia-reoxygenated (H-R) newborns. Severely hypoxic piglets had cardiogenic shock with depressed cardiac index (CI) and mean arterial pressure (MAP). The hemodynamics deteriorated gradually after initial recovery upon reoxygenation. Heart rate and CI improved with milrinone (D+M) and levosimendan (D+L) administration (P < 0.05 vs. control). Both regimens improved carotid arterial flow and carotid vascular resistance; D+M additionally improved superior mesentric arterial flow (all P < 0.05 vs. control). No effect was found on renal arterial flow or elevated lactate state with either regimen. D+M piglets also had a lower myocardial oxidized/reduced glutathione ratio (P < 0.05 vs. control). In conclusion, adding milrinone or levosimendan to dopamine similarly improved systemic hemodynamics in H-R newborn piglets. Milrinone also improved mesenteric perfusion and attenuated myocardial oxidative stress. Twenty-eight piglets (1-4 d, 1.5-2.5 kg) were instrumented for continuous monitoring of systemic MAP and pulmonary arterial pressure (PAP), CI, and carotid, superior mesenteric, and renal arterial flows. Piglets were randomized with blinding to sham-operated, H-R control (saline), and H-R dopamine (10 μg/kg/min) with D+M or D+L groups. H-R piglets underwent H-R followed by 2 h of drug infusion after reoxygenation. Tissue was collected for biochemical/oxidative stress testing and histological analysis.

Pleth variability index and respiratory system compliance to direct PEEP settings in mechanically ventilated patients, an exploratory study.

PubMed

Zhou, Jing; Han, Yi

2016-01-01

To analyze the ability of pleth variability index (PVI) and respiratory system compliance (RSC) on evaluating the hemodynamic and respiratory effects of positive end expiratory pressure (PEEP), then to direct PEEP settings in mechanically ventilated critical patients. We studied 22 mechanically ventilated critical patients in the intensive care unit. Patients were monitored with classical monitor and a pulse co-oximeter, with pulse sensors attached to patients' index fingers. Hemodynamic data [heart rate (HR), perfusion index (PI), PVI, central venous pressure (CVP), mean arterial pressure (MAP), peripheral blood oxygen saturation (SPO2), peripheral blood oxygen content (SPOC) and peripheral blood hemoglobin (SPHB)] as well as the respiratory data [respiratory rate (RR), tidal volume (VT), RSC and controlled airway pressure] were recorded for 15 min each at 3 different levels of PEEP (0, 5 and 10 cmH2O). Different levels of PEEP (0, 5 and 10 cmH2O) had no obvious effect on RR, HR, MAP, SPO2 and SPOC. However, 10 cmH2O PEEP induced significant hemodynamic disturbances, including decreases of PI, and increases of both PVI and CVP. Meanwhile, 5 cmH2O PEEP induced no significant changes on hemodynamics such as CVP, PI and PVI, but improved the RSC. RSC and PVI may be useful in detecting the hemodynamic and respiratory effects of PEEP, thus may help clinicians individualize PEEP settings in mechanically ventilated patients.

Epsilon-aminocaproic acid improves postrecirculation hemodynamics by reducing intraliver activated protein C consumption in orthotopic liver transplantation.

PubMed

Kong, H Y; Wen, X H; Huang, S Q; Zhu, S M

2014-01-01

Activated protein C (APC) is related to regulating the inflammatory response and hemodynamic stability upon reperfusion in cardiac operations and orthotopic liver transplantation (OLT). Epsilon-aminocaproic acid (EACA) is frequently used to treat fibrinolysis during OLT. It also has inhibitory effects related to the inflammatory response. However, it remains to be determined whether EACA can attenuate intraliver APC consumption and improve hemodynamic stability after reperfusion during OLT. Fifty-nine recipients were randomized to receive either EACA (150 mg kg(-1) given intravenously prior to incision, followed by 15 mg kg(-1) h(-1) infusion until 2 h after the graft reperfusion) or the same volume of saline. Blood samples to assess plasma APC and protein C were obtained immediately before and after reperfusion from the inferior caval effluent or the portal veins for calculation of transliver differences (Δ). Hemodynamics and vasoactive medication use during the reperfusion period were observed in both groups. No transhepatic changes in protein C were found in either group. Immediately after reperfusion, a marked intraliver consumption of APC was noted in all recipients (P < 0.001), and intraliver consumption of APC in the control group was greater than that in the EACA-treated group (P < 0.05). Fewer requirements for vasoactive medication use after reperfusion and better initial graft function were noted in the EACA-treated group (P < 0.05). EACA can attenuate intraliver APC consumption and improve hemodynamic stability after reperfusion and initial graft function during OLT.

Wall Thickness, Pulmonary Hypertension, and Diastolic Filling Abnormalities Predict Response to Postoperative Biventricular Pacing

PubMed Central

Brusen, Robin M.; Hahn, Rebecca; Cabreriza, Santos E.; Cheng, Bin; Wang, Daniel Y.; Truong, Wanda; Spotnitz, Henry M.

2017-01-01

Objective Post-cardiopulmonary bypass biventricular pacing improves hemodynamics but without clearly defined predictors of response. Based on preclinical studies and prior observations, it was suspected that diastolic dysfunction or pulmonary hypertension is predictive of hemodynamic benefit. Design Randomized controlled study of temporary biventricular pacing after cardiopulmonary bypass. Setting Single-center study at university-affiliated tertiary care hospital. Interventions Patients who underwent bypass with pre-operative ejection fraction ≤40% and QRS duration ≥100 ms or double-valve surgery were enrolled. At 3 time points between separation from bypass and postoperative day 1, pacing delays were varied to optimize hemodynamics. Participants Data from 43 patients were analyzed. Measurements and Main Results Cardiac output and arterial pressure were measured under no pacing, atrial pacing, and biventricular pacing. Preoperative echocardiograms and pulmonary artery catheterizations were reviewed, and measures of both systolic and diastolic function were compared to hemodynamic response. Early after separation, improvement in cardiac output was positively correlated with pulmonary vascular resistance (R2 = 0.97, p < 0.001), ventricle wall thickness (R2 = 0.72, p = 0.002)), and E/e′, a measure of abnormal diastolic ventricular filling velocity (R2 = 0.56, p = 0.04). Similar trends were seen with mean arterial pressure. QRS duration and ejection fraction did not correlate significantly with improvements in hemodynamics. Conclusions There may be an effect of biventricular pacing related to amelioration of abnormal diastolic filling patterns rather than electrical resynchronization in the postoperative state. PMID:25998068

Mitral valve resistance determines hemodynamic consequences of severe rheumatic mitral stenosis and immediate outcomes of percutaneous valvuloplasty.

PubMed

Sanati, Hamidreza; Zolfaghari, Reza; Samiei, Niloufar; Rezaei, Yousef; Chitsazan, Mitra; Zahedmehr, Ali; Shakerian, Farshad; Kiani, Reza; Firouzi, Ata; Rezaei Tabrizi, Reza

2017-02-01

The mitral valve area (MVA) poorly reflects the hemodynamic status of (MS). In this study, we compared the MVA with mitral valve resistance (MVR) with regard to the determination of hemodynamic consequences of MS and the immediate outcomes of percutaneous balloon mitral valvuloplasty (PBMV). In a prospective study, 36 patients with severe rheumatic MS with left ventricular ejection fraction (LVEF) >50% were evaluated. They underwent transthoracic echocardiography (TTE) and catheterization. The MVA was measured by two-dimensional planimetry and pressure half-time (PHT), and the MVR was calculated using the equation: 1333 × transmitral pressure gradient mean transmitral diastolic flow rate. The patients' mean age was 47.8±10.5 years. MVR ≥140.6 dynes·s/cm 5 detected systolic pulmonary arterial pressure (sPAP) >55 mm Hg with a sensitivity of 100% and a specificity of 74%. The sensitivity and specificity of MVA<0.75 cm 2 to discriminate elevated sPAP were 81% and 89%, respectively. PHT ≥323.5 mseconds had a sensitivity of 78% and a specificity of 96% to detect an elevated sPAP. To predict a successful PBMV, preprocedural MVR ≥106.1 dynes·s/cm 5 had a sensitivity of 100% and a specificity of 67% (area under the curve [AUC]=0.763; 95% confidence interval [CI]=0.520-1.006; P=.034); preprocedural MVA <0.95 cm 2 had a sensitivity of 78% and a specificity of 73% (AUC=0.730; 95% CI=0.503-0.956; P=.065); and preprocedural PHT ≥210.5 mseconds had a sensitivity of 73% and a specificity of 78% (AUC=0.707; 95% CI=0.474-0.941; P=.095). MVR seems to be more accurate than MVA in determining the hemodynamic consequences of severe MS as determined by sPAP. In addition, preprocedural MVR detected successful PBMVs. © 2017, Wiley Periodicals, Inc.

[Quantitative Measurements on the Blood Flow Fields of Left Atrial Appendage using Vector Flow Mapping in Patients with Nonvalvular Atrial Fibrillation].

PubMed

Cai, Yu-Yan; Wei, Xin; Zhang, Xiao-Ling; Liu, Gu-Yue; Li, Xi; Tang, Hong

2018-01-01

To quantify the hemodynamic characteristics of patients with nonvalvular atrial fibrillation. Twenty patients with paroxysmal atrial fibrillation and 15 patients with persistent atrial fibrillation enrolled in this study,while 12 patients with sinus rhythms served as controls. The hemodynamic characteristics of the patients in left atrial appendage were measured by transesophageal echocardiography (TEE) and vector flow mapping (VFM) using indicators such as vectors,vortex and energy loss (EL). ① Significant differences appeared between the patients with atrial fibrillation and the controls in heart rate,size of left atrium,size of left atrial appendage (LAA),and velocities of LAA filling and emptying. ② Regular vectors in LAA in early systole and late diastole were found in the patients with paroxysmal atrial fibrillation and the controls; whereas,irregular vectors with direction alternating were visualized in the whole cardiac cycle in the patients with persistent atrial fibrillation. ③ Small vortexes were observed at the opening of the left atrial appendage in late diastole in the patients with paroxysmal atrial fibrillation and the controls. ④ Peak EL values occurred in early systole and late diastole in the patients with paroxysmal atrial fibrillation and the controls. But the patients with persistent atrial fibrillation had increased EL values over the whole cardiac cycle. VFM can visualize and quantify the hemodynamics of LAA in patients with different heart rhythms. It may provide a new method for assessing atrial fibrillation. CopyrightCopyright© by Editorial Board of Journal of Sichuan University (Medical Science Edition).

Preliminary experience with a new device for delayed sternal closure strategy in cardiac surgery.

PubMed

Santini, Francesco; Onorati, Francesco; Telesca, Mariassunta; Faggian, Giuseppe; Mazzucco, Alessandro

2012-06-01

Open chest management with delayed sternal closure (DSC) is a valuable strategy in the management of patients with postcardiotomy hemodynamic instability or severe coagulopathy. The conventional extemporized material available for off-label sternal stenting however may limit its efficacy. We evaluated outcomes of patients with refractory severe postcardiotomy cardiogenic shock (SPCCS) treated with DSC using a novel temporary sternal spreader (NTSS) which allows myocardial recovery by progressive controlled approximation of the sternal edges. Seven patients (4 male, mean age 66.5 ± 5 years) with refractory SPCCS showing acute hemodynamic instability at sternal closure, were implanted with the NTSS, consisting of stainless-steel branches linked to 2 diverging plates of polyether-ether ketone, whose progressive opening/closing mechanism can be controlled from outside the chest with a rotating steel wire. The sternal wound was closed by an elastic membrane to achieve a sterile field. Swan-Ganz monitoring was employed, and clinical outcomes evaluated. The device was successfully implanted in all patients without device-related complications or failures. Progressive approximation of sternal edges, titrated on cardiac index values, was successfully completed allowing subsequent uneventful sternal closure in all. Mean time from SPCCS to sternal closure was 70 ± 21 hours. No patient developed infective complications or late hemodynamic instability after device removal and sternal closure. One patient (14%) died of multiorgan failure on postoperative day 9. Despite the limited number of patients enrolled, the NTSS proved safe and effective in allowing complete myocardial recovery after SPCCS, avoiding hemodynamic instability related to abrupt sternal closure, with no occurrence of infective complications.

Diagnosis of occlusal dysesthesia utilizing prefrontal hemodynamic activity with slight occlusal interference.

PubMed

Ono, Yumie; Ishikawa, Yu; Munakata, Motohiro; Shibuya, Tomoaki; Shimada, Atsushi; Miyachi, Hideo; Wake, Hiroyuki; Tamaki, Katsushi

2016-11-01

Clinical diagnosis of occlusal dysesthesia (OD), also referred to as phantom bite syndrome, is currently based on the absence of objective occlusal discrepancy despite the persistent complaint of uncomfortable bite sensation. We previously demonstrated that the subjective feeling of occlusal discomfort generated by artificial occlusal interference can be objectively evaluated using prefrontal hemodynamic activity in young healthy individuals. The aim of this study was to investigate whether dental patients with and without OD show distinct prefrontal activity during grinding behavior with an occlusal interference. Six dental patients with OD (OD group) and eight patients without OD (control group) grinded piled occlusal strips placed between their first molars and reported their perception and discomfort thresholds during continuous monitoring of prefrontal hemodynamic activity with a portable functional near-infrared spectroscopy. Although patients without OD showed the typical hemodynamic pattern of increased oxyhemoglobin and reduced deoxyhemoglobin (HHb) concentration, those with OD showed persistent incremental increases of HHb concentration that began at the loading of occlusal strips on their molars before they executed grinding. The intensities of the task-related HHb activities showed statistically significant differences between OD and control groups, particularly at channel 3, arranged over the left frontal pole cortex. When the discrimination criterion was set using the intensity values of channel 3 from both groups, the overall accuracy of the OD discrimination was 92.9%. Although physiological interpretation has yet to be elucidated, the task-related response of an increase in HHb may be a useful neuronal signature to characterize dental patients with OD.

Diagnosis of occlusal dysesthesia utilizing prefrontal hemodynamic activity with slight occlusal interference

PubMed Central

Ishikawa, Yu; Munakata, Motohiro; Shibuya, Tomoaki; Shimada, Atsushi; Miyachi, Hideo; Wake, Hiroyuki; Tamaki, Katsushi

2016-01-01

Clinical diagnosis of occlusal dysesthesia (OD), also referred to as phantom bite syndrome, is currently based on the absence of objective occlusal discrepancy despite the persistent complaint of uncomfortable bite sensation. We previously demonstrated that the subjective feeling of occlusal discomfort generated by artificial occlusal interference can be objectively evaluated using prefrontal hemodynamic activity in young healthy individuals. The aim of this study was to investigate whether dental patients with and without OD show distinct prefrontal activity during grinding behavior with an occlusal interference. Six dental patients with OD (OD group) and eight patients without OD (control group) grinded piled occlusal strips placed between their first molars and reported their perception and discomfort thresholds during continuous monitoring of prefrontal hemodynamic activity with a portable functional near‐infrared spectroscopy. Although patients without OD showed the typical hemodynamic pattern of increased oxyhemoglobin and reduced deoxyhemoglobin (HHb) concentration, those with OD showed persistent incremental increases of HHb concentration that began at the loading of occlusal strips on their molars before they executed grinding. The intensities of the task‐related HHb activities showed statistically significant differences between OD and control groups, particularly at channel 3, arranged over the left frontal pole cortex. When the discrimination criterion was set using the intensity values of channel 3 from both groups, the overall accuracy of the OD discrimination was 92.9%. Although physiological interpretation has yet to be elucidated, the task‐related response of an increase in HHb may be a useful neuronal signature to characterize dental patients with OD. PMID:29744159

Prolonged hemodynamic response during incidental facial emotion processing in inter-episode bipolar I disorder.

PubMed

Rosenfeld, Ethan S; Pearlson, Godfrey D; Sweeney, John A; Tamminga, Carol A; Keshavan, Matcheri S; Nonterah, Camilla; Stevens, Michael C

2014-03-01

This fMRI study examined whether hemodynamic responses to affectively-salient stimuli were abnormally prolonged in remitted bipolar disorder, possibly representing a novel illness biomarker. A group of 18 DSM-IV bipolar I-diagnosed adults in remission and a demographically-matched control group performed an event-related fMRI gender-discrimination task in which face stimuli had task-irrelevant neutral, happy or angry expressions designed to elicit incidental emotional processing. Participants' brain activation was modeled using a "fully informed" SPM5 basis set. Mixed-model ANOVA tested for diagnostic group differences in BOLD response amplitude and shape within brain regions-of-interest selected from ALE meta-analysis of previous comparable fMRI studies. Bipolar-diagnosed patients had a generally longer duration and/or later-peaking hemodynamic response in amygdala and numerous prefrontal cortex brain regions. Data are consistent with existing models of bipolar limbic hyperactivity, but the prolonged frontolimbic response more precisely details abnormalities recognized in previous studies. Prolonged hemodynamic responses were unrelated to stimulus type, task performance, or degree of residual mood symptoms, suggesting an important novel trait vulnerability brain dysfunction in bipolar disorder. Bipolar patients also failed to engage pregenual cingulate and left orbitofrontal cortex-regions important to models of automatic emotion regulation-while engaging a delayed dorsolateral prefrontal cortex response not seen in controls. These results raise questions about whether there are meaningful relationships between bipolar dysfunction of specific ventromedial prefrontal cortex regions believed to automatically regulate emotional reactions and the prolonged responses in more lateral aspects of prefrontal cortex.

Monitoring of hemodynamic changes induced in the healthy breast through inspired gas stimuli with MR-guided diffuse optical imaging

PubMed Central

Carpenter, C. M.; Rakow-Penner, R.; Jiang, S.; Pogue, B. W.; Glover, G. H.; Paulsen, K. D.

2010-01-01

Purpose: The modulation of tissue hemodynamics has important clinical value in medicine for both tumor diagnosis and therapy. As an oncological tool, increasing tissue oxygenation via modulation of inspired gas has been proposed as a method to improve cancer therapy and determine radiation sensitivity. As a radiological tool, inducing changes in tissue total hemoglobin may provide a means to detect and characterize malignant tumors by providing information about tissue vascular function. The ability to change and measure tissue hemoglobin and oxygenation concentrations in the healthy breast during administration of three different types of modulated gas stimuli (oxygen∕carbogen, air∕carbogen, and air∕oxygen) was investigated. Methods: Subjects breathed combinations of gases which were modulated in time. MR-guided diffuse optical tomography measured total hemoglobin and oxygen saturation in the breast every 30 s during the 16 min breathing stimulus. Metrics of maximum correlation and phase lag were calculated by cross correlating the measured hemodynamics with the stimulus. These results were compared to an air∕air control to determine the hemodynamic changes compared to the baseline physiology. Results: This study demonstrated that a gas stimulus consisting of alternating oxygen∕carbogen induced the largest and most robust hemodynamic response in healthy breast parenchyma relative to the changes that occurred during the breathing of room air. This stimulus caused increases in total hemoglobin and oxygen saturation during the carbogen phase of gas inhalation, and decreases during the oxygen phase. These findings are consistent with the theory that oxygen acts as a vasoconstrictor, while carbogen acts as a vasodilator. However, difficulties in inducing a consistent change in tissue hemoglobin and oxygenation were observed because of variability in intersubject physiology, especially during the air∕oxygen or air∕carbogen modulated breathing protocols. Conclusions: MR-guided diffuse optical imaging is a unique tool that can measure tissue hemodynamics in the breast during modulated breathing. This technique may have utility in determining the therapeutic potential of pretreatment tissue oxygenation or in investigating vascular function. Future gas modulation studies in the breast should use a combination of oxygen and carbogen as the functional stimulus. Additionally, control measures of subject physiology during air breathing are critical for robust measurements. PMID:20443485

Hemodynamic and clinical impact of ultrasound-derived venous reflux parameters.

PubMed

Neglén, Peter; Egger, John F; Olivier, Jake; Raju, Seshadri

2004-08-01

This study was undertaken to assess which ultrasound-derived parameter was superior for measuring venous reflux quantitatively and to evaluate the importance of popliteal vein valve reflux. A retrospective analysis was performed of 244 refluxive limbs in 182 patients who underwent ultrasound scanning, venous pressure measurement, air plethysmography, and clinical classification of severity according to the CEAP score. Reflux time (RT, s), peak reflux velocity (PRV, m/s), time of average rate of reflux (TAF, mL/min), absolute displaced volume retrogradely (ADV, mL) were compared to clinical class, ambulatory venous pressure (% drop), venous filling time (s), and venous filling index (mL/s) using nonparametric statistical tests. A P value of <.05 was considered significant. Limbs were divided into 3 groups: (A) axial great saphenous vein reflux only (n = 68); (B) axial deep reflux including popliteal vein incompetence with or without concomitant gastrocnemius or great or small saphenous vein reflux (all ultrasound reflux parameters of each refluxive vein added at the knee level) (n = 79); and (C) all limbs with popliteal vein reflux (the ultrasound data of the refluxive popliteal vein exclusively was used in comparison regardless of concomitant associated reflux) (n = 103). Limbs were also stratified into limbs with skin changes and ulcer (C-class 4-6) and those without (C-class 1-3) and subsequently compared. No meaningful significant correlation was found between RT and the clinical and hemodynamic results in groups A and B. The PRV and TAF correlated significantly with the hemodynamic parameters. The PRV and TAF and clinical severity trended towards correlation in group A (P =.0554 and P =.0998, respectively), but was significantly correlated in group B. The poor hemodynamic condition in the subset of C-class 4-6 limbs in groups A and B was reflected in a greater PRV, TAF, and ADV in this subset as compared with the limbs in C-class 1-3. RT was not significantly different in the subsets of limbs, further suggesting that RT is not related to hemodynamic or clinical state of the limbs. No meaningful correlations were found in group C. Although the hemodynamic data were significantly poorer in the subset of limbs with C-class 4-6 than in C-class 1-3, the ultrasound-derived parameters were not significantly different. The duration of valve reflux time (or valve closure time) cannot be used to quantify severity of reflux and is purely a qualitative measurement. The PRV and the rate of reflux appeared to better reflect the magnitude of venous incompetence. In the presence of axial reflux, it appeared logical and physiologically correct to sum up these reflux parameters for each venous segment crossing the knee. The popliteal valve reflux (the "gatekeeper" function) was not in itself an important determinant of venous hemodynamics and clinical severity. Additional reflux in other venous segments must be taken into account.

[Treatment of acute respiratory distress syndrome using pressure and volume controlled ventilation with lung protective strategy].

PubMed

Ge, Ying; Wan, Yong; Wang, Da-qing; Su, Xiao-lin; Li, Jun-ying; Chen, Jing

2004-07-01

To investigate the significance and effect of pressure controlled ventilation (PCV) as well as volume controlled ventilation (VCV) by lung protective strategy on respiratory mechanics, blood gas analysis and hemodynamics in patients with acute respiratory distress syndrome (ARDS). Fifty patients with ARDS were randomly divided into PCV and VCV groups with permissive hypercapnia and open lung strategy. Changes in respiratory mechanics, blood gas analysis and hemodynamics were compared between two groups. Peak inspiration pressure (PIP) in PCV group was significantly lower than that in VCV group, while mean pressure of airway (MPaw) was significantly higher than that in VCV after 24 hours mechanical ventilation. After 24 hours mechanical ventilation, there were higher central venous pressure (CVP) and slower heart rate (HR) in two groups, CVP was significantly higher in VCV compared with PCV, and PCV group had slower HR than VCV group, the two groups had no differences in mean blood pressure (MBP) at various intervals. All patients showed no ventilator-induced lung injury. Arterial blood oxygenations were obviously improved in two groups after 24 hours mechanical ventilation, PCV group had better partial pressure of oxygen in artery (PaO2) than VCV group. Both PCV and VCV can improve arterial blood oxygenations, prevent ventilator-induced lung injury, and have less disturbance in hemodynamic parameters. PCV with lung protective ventilatory strategy should be early use for patients with ARDS.

[The anesthesiological procedure for correcting preloading in the surgery of acquired mitral valve defects].

PubMed

Kiselev, V O; Shipulin, V M; Evtushenko, A V; Podoksenov, Iu K; Shishneva, E V

2000-01-01

Intraoperative correction of preload in patients with acquired valvular disease (AVD) complicated by right-ventricular failure and severe pulmonary hypertension necessitates search for pathogenetically based algorithms of anesthesiological strategy. The objective of this study was to develop a strategy of assessing and treating the preload at the stage of induction anesthesia in patients with right-ventricular failure. During surgery central hemodynamic parameters and their response to a short head-down-tilt (15-20 degrees) were evaluated in patients (n = 42) with cardiac index (CI) less than 2 l/min/m2 after induction anesthesia. The patients were divided into 2 groups with different severity of preoperative status. Group 1 (main) included 24 patients with stages II-III cardiac failure (according to N. Strazhesko and B. Vasilenko) and group 2 (control) consisted of 18 patients with stage IIA cardiac failure. Progressing preoperative cardiac failure resulted in decrease of cardiac index and failure of compensatory hemodynamic mechanisms in AVD patients. The level of right-ventricular preload, pulmonary resistance, and stroke index were lower in group 1 than in the controls; however, 8% of group 1 patients responded positively to increased preload. In the control group 50% responded favorably to head-down-tilt. Hence, comprehensive assessment of cardiac index, central hemodynamic parameters and their response to head-down tilt help individually choose the anesthesiological strategy.

Obturator Artery Injury Resulting in Massive Hemorrhage From a Low-Energy Pubic Ramus Fracture.

PubMed

Solarz, Mark K; Kistler, Justin M; Rehman, Saqib

2017-05-01

Pelvic ring fractures are common in the elderly population and are usually a result of low-energy trauma, such as falls from standing. In most cases, low-energy pelvic ring injuries can be treated with appropriate analgesia and early mobilization. Arterial injury resulting in hemodynamic instability from a low-energy pelvic ring injury is rare but, given the poor compliance of vessels in the elderly population, possible. These patients must be carefully monitored after the initial injury. The purpose of this report is to describe an elderly patient who sustained a superior pubic ramus fracture and arterial injury following a low-energy fall from standing that required angiographic intervention. Elderly patients who sustain low-energy or pelvic insufficiency fractures are unlike the younger population with high-energy pelvic fractures and hemodynamic collapse. Elderly patients can have a delayed presentation of arterial injury and require careful physical examination and close monitoring. Additionally, the authors provide a review of the literature for low-energy pelvic fractures. [Orthopedics. 2017; 40(3):e546-e548.]. Copyright 2017, SLACK Incorporated.

APTR is a prognostic marker in cirrhotic patients with portal hypertension during TIPS procedure.

PubMed

Yu, Shanshan; Qi, Yanhua; Jiang, Jue; Wang, Hua; Zhou, Qi

2018-03-01

Portal hypertension is a major cause of mortality and morbidity in cirrhotic patients. In this study, we aimed to analyze the clinical characteristics of Alu-mediated p21 transcriptional regulator (APTR) during transjugular intrahepatic portosystemic shunt (TIPS) procedure. Portal and hepatic venous blood was drawn from 84 patients with liver cirrhosis and portal hypertension before and after TIPS treatment. Then, we detected biochemical, hemodynamic parameters and APTR expression before and after TIPS treatment. Indeed, TIPS treatment could markedly ameliorate the serum blood urea nitrogen (BUN) level and portal vein hemodynamics in cirrhotic patients. We found that portal venous levels of APTR was significantly decreased after TIPS treatment and its aberrant expression levels were positively correlated with Model for End Stage Liver Disease (MELD), portal hepatic venous pressure gradient (PHPG) in patients. Higher APTR expression in portal vein was associated with poor prognosis. APTR level in portal vein was an independent predictors of mortality. Our data indicated that APTR may serve as a novel biomarker for cirrhotic patients with portal hypertension before and after receiving TIPS. Copyright © 2017 Elsevier B.V. All rights reserved.

Prefrontal hemodynamic responses and the degree of flow experience among occupational therapy students during their performance of a cognitive task.

PubMed

Hirao, Kazuki

2014-01-01

Although flow experience is positively associated with motivation to learn, the biological basis of flow experience is poorly understood. Accumulation of evidence on the underlying brain mechanisms related to flow is necessary for a deeper understanding of the motivation to learn. The purpose of this study is to investigate the relationship between flow experience and brain function using near-infrared spectroscopy (NIRS) during the performance of a cognitive task. Sixty right-handed occupational therapy (OT) students participated in this study. These students performed a verbal fluency test (VFT) while 2-channel NIRS was used to assess changes in oxygenated hemoglobin concentration (oxygenated hemoglobin [oxy-Hb]) in the prefrontal cortex. Soon after that, the OT students answered the flow questionnaire (FQ) to assess the degree of flow experience during the VFT. Average oxy-Hb in the prefrontal cortex had a significant negative correlation with the satisfaction scores on the FQ. Satisfaction during the flow experience correlated with prefrontal hemodynamic suppression. This finding may assist in understanding motivation to learn and related flow experience.

Emotional Stress as a Risk for Hypertension in Sub-Saharan Africans: Are We Ignoring the Odds?

PubMed

Malan, Leoné; Malan, Nico T

2017-01-01

Globally most interventions focus on improving lifestyle habits and treatment regimens to combat hypertension as a non-communicable disease (NCD). However, despite these interventions and improved medical treatments, blood pressure (BP) values are still on the rise and poorly controlled in sub-Saharan Africa (SSA). Other factors contributing to hypertension prevalence, such as chronic emotional stress, might provide some insight for future health policy approaches.Currently, Hypertension Society guidelines do not mention emotional stress as a probable cause for hypertension. Recently the 2014 World Global Health reports, suggested that African governments should consider using World Health Organization hypertension data as a proxy indicator for social well-being. However, the possibility that a stressful life and taxing environmental factors might disturb central neural control of BP regulation has largely been ignored in SSA.Linking emotional stress to vascular dysregulation is therefore one way to investigate increased cardiometabolic challenges, neurotransmitter depletion and disturbed hemodynamics. Disruption of stress response pathways and subsequent changes in lifestyle habits as ways of coping with a stressful life, and as probable cause for hypertension prevalence in SSA, may be included in future preventive measures. We will provide an overview on emotional stress and central neural control of BP and will include also implications thereof for clinical practice in SSA cohorts.

A cohort study of neurodevelopmental outcome in children with DiGeorge syndrome following cardiac surgery.

PubMed

Maharasingam, M; Ostman-Smith, I; Pike, M G

2003-01-01

To examine whether the learning difficulties seen in a proportion of children with DGS are secondary to cardiac pathology and treatment, or a feature of the DGS phenotype. Cohort study of all patients with DGS and coexisting cardiac lesions within a region. Ten children with 22q11 deletion were assigned two controls each, matched for age, sex, cardiac lesion, and preoperative hemodynamic status but without DGS. The neurodevelopmental status was evaluated with the Ruth Griffiths test for babies and young children. Children with the 22q11 deletion showed a wide range of developmental quotient (DQ; mean 71, 95% CI 47 to 95) and subscale scores, but these as a group were significantly lower than those of the control group (DQ 113, 95% CI 108 to 118). Four of the DGS children had DQs below 60. Hypocalcaemia, prolonged postoperative ventilation, and abnormal neurology perioperatively were associated with a low DQ. A proportion of children with DGS have a very poor developmental outcome following cardiac surgery. This outcome is not attributable to the cardiac condition and its treatment alone, but represents either a pre-existing component of the syndrome or an interaction between the syndrome and its treatment.

A biomimetic microfluidic model to study signalling between endothelial and vascular smooth muscle cells under hemodynamic conditions.

PubMed

van Engeland, Nicole C A; Pollet, Andreas M A O; den Toonder, Jaap M J; Bouten, Carlijn V C; Stassen, Oscar M J A; Sahlgren, Cecilia M

2018-05-29

Cell signalling and mechanics influence vascular pathophysiology and there is an increasing demand for in vitro model systems that enable examination of signalling between vascular cells under hemodynamic conditions. Current 3D vessel wall constructs do not recapitulate the mechanical conditions of the native tissue nor do they allow examination of cell-cell interactions under relevant hemodynamic conditions. Here, we describe a 3D microfluidic chip model of arterial endothelial and smooth muscle cells where cellular organization, composition and interactions, as well as the mechanical environment of the arterial wall are mimicked. The hemodynamic EC-VSMC-signalling-on-a-chip consists of two parallel polydimethylsiloxane (PDMS) cell culture channels, separated by a flexible, porous PDMS membrane, mimicking the porosity of the internal elastic lamina. The hemodynamic EC-VSMC-signalling-on-a-chip allows co-culturing of human aortic endothelial cells (ECs) and human aortic vascular smooth muscle cells (VSMCs), separated by a porous membrane, which enables EC-VSMC interaction and signalling, crucial for the development and homeostasis of the vessel wall. The device allows real time cell imaging and control of hemodynamic conditions. The culture channels are surrounded on either side by vacuum channels to induce cyclic strain by applying cyclic suction, resulting in mechanical stretching and relaxation of the membrane in the cell culture channels. The blood flow is mimicked by creating a flow of medium at the EC side. Vascular cells remain viable during prolonged culturing, exhibit physiological morphology and organization and make cell-cell contact. During dynamic culturing of the device with a shear stress of 1-1.5 Pa and strain of 5-8%, VSMCs align perpendicular to the given strain in the direction of the flow and EC adopt a cobblestone morphology. To our knowledge, this is the first report on the development of a microfluidic device, which enables a co-culture of interacting ECs and VSMCs under hemodynamic conditions and presents a novel approach to systematically study the biological and mechanical components of the intimal-medial vascular unit.

Mathematical Modeling of Renal Hemodynamics in Physiology and Pathophysiology

PubMed Central

Sgouralis, Ioannis; Layton, Anita T.

2015-01-01

In addition to the excretion of metabolic waste and toxin, the kidney plays an indispensable role in regulating the balance of water, electrolyte, acid-base, and blood pressure. For the kidney to maintain proper functions, hemodynamic control is crucial. In this review, we describe representative mathematical models that have been developed to better understand the kidney's autoregulatory processes. We consider mathematical models that simulate glomerular filtration, and renal blood flow regulation by means of the myogenic response and tubuloglomerular feedback. We discuss the extent to which these modeling efforts have expanded the understanding of renal functions in health and disease. PMID:25765886

Impact of lipopolysaccharide-induced acute inflammation on baroreflex-controlled sympathetic arterial pressure regulation

PubMed Central

Tohyama, Takeshi; Kawada, Toru; Kishi, Takuya; Yoshida, Keimei; Nishikawa, Takuya; Mannoji, Hiroshi; Kamada, Kazuhiro; Sunagawa, Kenji; Tsutsui, Hiroyuki

2018-01-01

Background Lipopolysaccharide (LPS) induces acute inflammation, activates sympathetic nerve activity (SNA) and alters hemodynamics. Since the arterial baroreflex is a negative feedback system to stabilize arterial pressure (AP), examining the arterial baroreflex function is a prerequisite to understanding complex hemodynamics under LPS challenge. We investigated the impact of LPS-induced acute inflammation on SNA and AP regulation by performing baroreflex open-loop analysis. Methods Ten anesthetized Sprague-Dawley rats were used. Acute inflammation was induced by an intravenous injection of LPS (60 μg/kg). We isolated the carotid sinuses from the systemic circulation and controlled carotid sinus pressure (CSP) by a servo-controlled piston pump. We matched CSP to AP to establish the baroreflex closed-loop condition, whereas we decoupled CSP from AP to establish the baroreflex open-loop condition and changed CSP stepwise to evaluate the baroreflex open-loop function. We recorded splanchnic SNA and hemodynamic parameters under baroreflex open- and closed-loop conditions at baseline and at 60 and 120 min after LPS injection. Results In the baroreflex closed-loop condition, SNA continued to increase after LPS injection, reaching three-fold the baseline value at 120 min (baseline: 94.7 ± 3.6 vs. 120 min: 283.9 ± 31.9 a.u.). In contrast, AP increased initially (until 75 min), then declined to the baseline level. In the baroreflex open-loop condition, LPS reset the neural arc (CSP-SNA relationship) upward to higher SNA, while shifted the peripheral arc (SNA-AP relationship) downward at 120 min after the injection. As a result, the operating point determined by the intersection between function curves of neural arc and peripheral arc showed marked sympatho-excitation without substantial changes in AP. Conclusions LPS-induced acute inflammation markedly increased SNA via resetting of the baroreflex neural arc, and suppressed the peripheral arc. The balance between the augmented neural arc and suppressed peripheral arc determines SNA and hemodynamics in LPS-induced acute inflammation. PMID:29329321

Impact of lipopolysaccharide-induced acute inflammation on baroreflex-controlled sympathetic arterial pressure regulation.

PubMed

Tohyama, Takeshi; Saku, Keita; Kawada, Toru; Kishi, Takuya; Yoshida, Keimei; Nishikawa, Takuya; Mannoji, Hiroshi; Kamada, Kazuhiro; Sunagawa, Kenji; Tsutsui, Hiroyuki

2018-01-01

Lipopolysaccharide (LPS) induces acute inflammation, activates sympathetic nerve activity (SNA) and alters hemodynamics. Since the arterial baroreflex is a negative feedback system to stabilize arterial pressure (AP), examining the arterial baroreflex function is a prerequisite to understanding complex hemodynamics under LPS challenge. We investigated the impact of LPS-induced acute inflammation on SNA and AP regulation by performing baroreflex open-loop analysis. Ten anesthetized Sprague-Dawley rats were used. Acute inflammation was induced by an intravenous injection of LPS (60 μg/kg). We isolated the carotid sinuses from the systemic circulation and controlled carotid sinus pressure (CSP) by a servo-controlled piston pump. We matched CSP to AP to establish the baroreflex closed-loop condition, whereas we decoupled CSP from AP to establish the baroreflex open-loop condition and changed CSP stepwise to evaluate the baroreflex open-loop function. We recorded splanchnic SNA and hemodynamic parameters under baroreflex open- and closed-loop conditions at baseline and at 60 and 120 min after LPS injection. In the baroreflex closed-loop condition, SNA continued to increase after LPS injection, reaching three-fold the baseline value at 120 min (baseline: 94.7 ± 3.6 vs. 120 min: 283.9 ± 31.9 a.u.). In contrast, AP increased initially (until 75 min), then declined to the baseline level. In the baroreflex open-loop condition, LPS reset the neural arc (CSP-SNA relationship) upward to higher SNA, while shifted the peripheral arc (SNA-AP relationship) downward at 120 min after the injection. As a result, the operating point determined by the intersection between function curves of neural arc and peripheral arc showed marked sympatho-excitation without substantial changes in AP. LPS-induced acute inflammation markedly increased SNA via resetting of the baroreflex neural arc, and suppressed the peripheral arc. The balance between the augmented neural arc and suppressed peripheral arc determines SNA and hemodynamics in LPS-induced acute inflammation.

Improvement in hemodynamic performance, exercise capacity, inflammatory profile, and left ventricular reverse remodeling after intracoronary delivery of mesenchymal stem cells in an experimental model of pressure overload hypertrophy.

PubMed

Molina, Ezequiel J; Palma, Jon; Gupta, Dipin; Torres, Denise; Gaughan, John P; Houser, Steven; Macha, Mahender

2008-02-01

In a rat model of pressure overload hypertrophy, we studied the effects of intracoronary delivery of mesenchymal stem cells on hemodynamic performance, exercise capacity, systemic inflammation, and left ventricular reverse remodeling. Sprague-Dawley rats underwent aortic banding and were followed up by echocardiographic scanning. After a decrease in fractional shortening of 25% from baseline, animals were randomized to intracoronary injection of mesenchymal stem cells (MSC group; n = 28) or phosphate-buffered saline solution (control group; n = 20). Hemodynamic and echocardiographic assessment, swim testing to exhaustion, and measurement of inflammatory markers were performed before the rats were humanely killed on postoperative day 7, 14, 21, or 28. Injection of mesenchymal stem cells improved systolic function in the MSC group compared with the control group (mean +/- standard deviation: maximum dP/dt 3048 +/- 230 mm Hg/s vs 2169 +/- 97 mm Hg/s at 21 days and 3573 +/- 741 mm Hg/s vs 1363 +/- 322 mm Hg/s at 28 days: P < .001). Time to exhaustion was similarly increased in the MSC group compared with controls (487 +/- 35 seconds vs 306 +/- 27 seconds at 28 days; P < .01). Serum levels of interleukins 1 and 6, tumor necrosis factor-alpha, and brain natriuretic peptide-32 were significantly decreased in animals treated with mesenchymal stem cells. Stem cell transplantation improved left ventricular fractional shortening at 21 and 28 days. Left ventricular end-systolic and end-diastolic diameters were also improved at 28 days. In this model of pressure overload hypertrophy, intracoronary delivery of mesenchymal stem cells during heart failure was associated with an improvement in hemodynamic performance, maximal exercise tolerance, systemic inflammation, and left ventricular reverse remodeling. This study suggests a potential role of this treatment strategy for the management of hypertrophic heart failure resulting from pressure overload.

Exercise excess pressure and exercise-induced albuminuria in patients with type 2 diabetes mellitus.

PubMed

Climie, Rachel E D; Srikanth, Velandai; Keith, Laura J; Davies, Justin E; Sharman, James E

2015-05-01

Exercise-induced albuminuria is common in patients with type 2 diabetes mellitus (T2DM) in response to maximal exercise, but the response to light-moderate exercise is unclear. Patients with T2DM have abnormal central hemodynamics and greater propensity for exercise hypertension. This study sought to determine the relationship between light-moderate exercise central hemodynamics (including aortic reservoir and excess pressure) and exercise-induced albuminuria. Thirty-nine T2DM (62 ± 9 yr; 49% male) and 39 nondiabetic controls (53 ± 9 yr; 51% male) were examined at rest and during 20 min of light-moderate cycle exercise (30 W; 50 revolutions/min). Albuminuria was assessed by the albumin-creatinine ratio (ACR) at rest and 30 min postexercise. Hemodynamics recorded included brachial and central blood pressure (BP), aortic stiffness, augmented pressure (AP), aortic reservoir pressure, and excess pressure integral (Pexcess). There was no difference in ACR between groups before exercise (P > 0.05). Exercise induced a significant rise in ACR in T2DM but not controls (1.73 ± 1.43 vs. 0.53 ± 1.0 mg/mol, P = 0.002). All central hemodynamic variables were significantly higher during exercise in T2DM (i.e., Pexcess, systolic BP and AP; P < 0.01 all). In T2DM (but not controls), exercise Pexcess was associated with postexercise ACR (r = 0.51, P = 0.002), and this relationship was independent of age, sex, body mass index, heart rate, aortic stiffness, antihypertensive medication, and ambulatory daytime systolic BP (β = 0.003, P = 0.003). Light-moderate exercise induced a significant rise in ACR in T2DM, and this was independently associated with Pexcess, a potential marker of vascular dysfunction. These novel findings suggest that Pexcess could be important for appropriate renal function in T2DM. Copyright © 2015 the American Physiological Society.

The reliability of the clinical examination in predicting hemodynamic status in acute febrile illness in a tropical, resource-limited setting.

PubMed

Moek, Felix; Poe, Poe; Charunwatthana, Prakaykaew; Pan-Ngum, Wirichada; Wattanagoon, Yupaporn; Chierakul, Wirongrong

2018-05-19

The clinical examination alone is widely considered unreliable when assessing fluid responsiveness in critically ill patients. Little evidence exists on the performance of the clinical examination to predict other hemodynamic derangements or more complex hemodynamic states. Patients with acute febrile illness were assessed on admission, both clinically and per non-invasive hemodynamic measurement. Correlations between clinical signs and hemodynamics patterns were analyzed, and the predictive capacity of the clinical signs was examined. Seventy-one patients were included; the most common diagnoses were bacterial sepsis, scrub typhus and dengue infection. Correlations between clinical signs and hemodynamic parameters were only statistically significant for Cardiac Index (r=0.75, p-value <0.01), Systemic Vascular Resistance Index (r=0.79, p-value <0.01) and flow time corrected (r=0.44, p-value 0.03). When assessing the predictive accuracy of clinical signs, the model identified only 62% of hemodynamic states correctly, even less if there was more than one hemodynamic abnormality. The clinical examination is not reliable to assess a patient's hemodynamic status in acute febrile illness. Fluid responsiveness, cardiodepression and more complex hemodynamic states are particularly easily missed.

Na2S, a fast-releasing H2S donor, given as suppository lowers blood pressure in rats.

PubMed

Tomasova, Lenka; Drapala, Adrian; Jurkowska, Halina; Wróbel, Maria; Ufnal, Marcin

2017-10-01

Hydrogen sulfide (H 2 S) is involved in blood pressure control. The available slow-releasing H 2 S-donors are poorly soluble in water and their ability to release H 2 S in biologically relevant amounts under physiological conditions is questionable. Therefore, new slow-releasing donors or new experimental approaches to fast-releasing H 2 S donors are needed. Hemodynamics and ECG were recorded in male, anesthetized Wistar Kyoto rats (WKY) and in Spontaneously hypertensive rats (SHR) at baseline and after: 1) intravenous (iv) infusion of vehicle or Na 2 S; 2) administration of vehicle suppositories or Na 2 S suppositories. Intravenously administered vehicle and vehicle suppositories did not affect mean arterial blood pressure (MABP) and heart rate (HR). Na 2 S administered iv caused a significant, but transient (2-5min) decrease in MABP. Na 2 S suppositories produced a dose-dependent hypotensive response that lasted ∼45min in WKY and ∼75-80min in SHR. It was accompanied by a decrease in HR in WKY, and an increase in HR in SHR. Na 2 S suppositories did not produce a significant change in corrected QT, an indicator of cardiotoxicity. Na 2 S suppositories increased blood level of thiosulfates, products of H 2 S oxidation. Na 2 S administered in suppositories exerts a prolonged hypotensive effect in rats, with no apparent cardiotoxic effect. SHR and WKY differ in hemodynamic response to the H 2 S donor. Suppository formulation of fast-releasing H 2 S donors may be useful in research, if a reference slow-releasing H 2 S donor is not available. Copyright © 2017 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Hemodynamic profile of pulmonary hypertension (PH) in ARDS

PubMed Central

Calcaianu, Mihaela; Gschwend, Anthony; Canuet, Matthieu; Meziani, Ferhat; Kessler, Romain

2017-01-01

Acute respiratory distress syndrome (ARDS) is a diffuse lung injury that leads to a severe acute respiratory failure. Traditional diagnostic criteria for pulmonary hypertension (PH), in this situation, may be unreliable due to the effects of positive pressure ventilation and vasoactive agents. The aim of this study is to describe the hemodynamic characteristics of PH secondary to ARDS, in relation with respiratory parameters. We assessed the hemodynamic, respiratory function, and ventilator parameters in a cohort of 38 individuals with ARDS-associated PH defined by mean pulmonary arterial pressure (mPAP) ≥ 25 mmHg. Individual characteristics: PaO2/FiO2 = 110 ± 60 mmHg, alveolar-arterial oxygen gradient (A-aO2) = 549 ± 148.9 mmHg, positive end-expiratory pressure (PEEP) = 8.7 ± 3.5 cmH2O, pulmonary static compliance (Cstat) = 30 ± 12.1 L*cmH2O-1, mPAP = 35.4 ±6.6 mmHg, pulmonary artery wedge pressure (PAWP) = 15.6 ± 5.5 mmHg, cardiac index (CI) = 3.4 ± 1.2 L/min/m2, pulmonary vascular resistance (PVR) = 3.3 ± 1.6 Wood units (WU), right atrial pressure (RAP) = 13.4 ± 5.4 mmHg, diastolic pulmonary gradient (DPG) = 12.6 ± 6.5 mmHg, and trans-pulmonary gradient (TPG) = 19.7 ± 7.7 mmHg. The composite marker—DPG >7 mmHg and PVR > 3 WU—is associated with lower CI (P = 0.016), higher mPAP (P = 0.003), and lower pulmonary static compliance (P = 0.028). We confirmed a poor prognosis of ARDS associated with PH, with a 50% survival rate after 17 days. We observed that the survival rate at 28 days was better in the case of improvement in the PaO2/FiO2 ratio in the first 24 h (log rank P = 0.003). ARDS associated with PH is a severe condition with a very poor survival rate. The composite marker DPG > 7 mmHg and PVR > 3 WU seemed to better describe the hemodynamic and respiratory dysfunction. The improvement in PaO2/FiO2 ratio in the first 24 h defined a better survival in our cohort of patients. PMID:29283029

Hemodynamic profile of pulmonary hypertension (PH) in ARDS.

PubMed

Calcaianu, George; Calcaianu, Mihaela; Gschwend, Anthony; Canuet, Matthieu; Meziani, Ferhat; Kessler, Romain

2018-01-01

Acute respiratory distress syndrome (ARDS) is a diffuse lung injury that leads to a severe acute respiratory failure. Traditional diagnostic criteria for pulmonary hypertension (PH), in this situation, may be unreliable due to the effects of positive pressure ventilation and vasoactive agents. The aim of this study is to describe the hemodynamic characteristics of PH secondary to ARDS, in relation with respiratory parameters. We assessed the hemodynamic, respiratory function, and ventilator parameters in a cohort of 38 individuals with ARDS-associated PH defined by mean pulmonary arterial pressure (mPAP) ≥ 25 mmHg. Individual characteristics: PaO2/FiO2 = 110 ± 60 mmHg, alveolar-arterial oxygen gradient (A-aO2) = 549 ± 148.9 mmHg, positive end-expiratory pressure (PEEP) = 8.7 ± 3.5 cmH 2 O, pulmonary static compliance (Cstat) = 30 ± 12.1 L*cmH 2 O-1, mPAP = 35.4 ±6.6 mmHg, pulmonary artery wedge pressure (PAWP) = 15.6 ± 5.5 mmHg, cardiac index (CI) = 3.4 ± 1.2 L/min/m 2 , pulmonary vascular resistance (PVR) = 3.3 ± 1.6 Wood units (WU), right atrial pressure (RAP) = 13.4 ± 5.4 mmHg, diastolic pulmonary gradient (DPG) = 12.6 ± 6.5 mmHg, and trans-pulmonary gradient (TPG) = 19.7 ± 7.7 mmHg. The composite marker-DPG >7 mmHg and PVR > 3 WU-is associated with lower CI ( P = 0.016), higher mPAP ( P = 0.003), and lower pulmonary static compliance ( P = 0.028). We confirmed a poor prognosis of ARDS associated with PH, with a 50% survival rate after 17 days. We observed that the survival rate at 28 days was better in the case of improvement in the PaO2/FiO2 ratio in the first 24 h (log rank P = 0.003). ARDS associated with PH is a severe condition with a very poor survival rate. The composite marker DPG > 7 mmHg and PVR > 3 WU seemed to better describe the hemodynamic and respiratory dysfunction. The improvement in PaO2/FiO2 ratio in the first 24 h defined a better survival in our cohort of patients.

Vascular Adaptation to Exercise in Humans: Role of Hemodynamic Stimuli

PubMed Central

Green, Daniel J.; Hopman, Maria T. E.; Padilla, Jaume; Laughlin, M. Harold; Thijssen, Dick H. J.

2017-01-01

On the 400th anniversary of Harvey's Lumleian lectures, this review focuses on “hemodynamic” forces associated with the movement of blood through arteries in humans and the functional and structural adaptations that result from repeated episodic exposure to such stimuli. The late 20th century discovery that endothelial cells modify arterial tone via paracrine transduction provoked studies exploring the direct mechanical effects of blood flow and pressure on vascular function and adaptation in vivo. In this review, we address the impact of distinct hemodynamic signals that occur in response to exercise, the interrelationships between these signals, the nature of the adaptive responses that manifest under different physiological conditions, and the implications for human health. Exercise modifies blood flow, luminal shear stress, arterial pressure, and tangential wall stress, all of which can transduce changes in arterial function, diameter, and wall thickness. There are important clinical implications of the adaptation that occurs as a consequence of repeated hemodynamic stimulation associated with exercise training in humans, including impacts on atherosclerotic risk in conduit arteries, the control of blood pressure in resistance vessels, oxygen delivery and diffusion, and microvascular health. Exercise training studies have demonstrated that direct hemodynamic impacts on the health of the artery wall contribute to the well-established decrease in cardiovascular risk attributed to physical activity. PMID:28151424

Should adrenaline be used in patients with hemodynamically stable anaphylaxis? Incident case control study nested within a retrospective cohort study.

PubMed

Ko, Byuk Sung; Kim, Ji Yeon; Seo, Dong-Woo; Kim, Won Young; Lee, Jae Ho; Sheikh, Aziz; Bates, David W

2016-02-03

Although adrenaline (epinephrine) is a cornerstone of initial anaphylaxis treatment, it is not often used. We sought to assess whether use of adrenaline in hemodynamically stable patients with anaphylaxis could prevent the development of hypotension. We conducted a retrospective cohort study of 761 adult patients with anaphylaxis presenting to the emergency department (ED) of a tertiary care hospital over a 10-year period. We divided the patients into two groups according to the occurrence of hypotension and compared demographic characteristics, clinical features, treatments and outcomes. Of the 340 patients with anaphylaxis who were normotensive at first presentation, 40 patients experienced hypotension during their ED stay. The ED stay of the hypotension group was significantly longer than that of patients who did not experience hypotension (496 min vs 253 min, P = 0.000). Adrenaline use in hemodynamically stable anaphylaxis patient was independently associated with a lower risk of developing in-hospital occurrence of hypotension: OR, 0.254 [95% CI, 0.091-0.706]. Adrenaline use in hemodynamically stable anaphylaxis patients was associated with a reduced risk of developing in-hospital occurrence of hypotension. Adverse events induced by adrenaline were rare when the intramuscular route was used.

Should adrenaline be used in patients with hemodynamically stable anaphylaxis? Incident case control study nested within a retrospective cohort study

PubMed Central

Ko, Byuk Sung; Kim, Ji Yeon; Seo, Dong-Woo; Kim, Won Young; Lee, Jae Ho; Sheikh, Aziz; Bates, David W.

2016-01-01

Although adrenaline (epinephrine) is a cornerstone of initial anaphylaxis treatment, it is not often used. We sought to assess whether use of adrenaline in hemodynamically stable patients with anaphylaxis could prevent the development of hypotension. We conducted a retrospective cohort study of 761 adult patients with anaphylaxis presenting to the emergency department (ED) of a tertiary care hospital over a 10-year period. We divided the patients into two groups according to the occurrence of hypotension and compared demographic characteristics, clinical features, treatments and outcomes. Of the 340 patients with anaphylaxis who were normotensive at first presentation, 40 patients experienced hypotension during their ED stay. The ED stay of the hypotension group was significantly longer than that of patients who did not experience hypotension (496 min vs 253 min, P = 0.000). Adrenaline use in hemodynamically stable anaphylaxis patient was independently associated with a lower risk of developing in-hospital occurrence of hypotension: OR, 0.254 [95% CI, 0.091–0.706]. Adrenaline use in hemodynamically stable anaphylaxis patients was associated with a reduced risk of developing in-hospital occurrence of hypotension. Adverse events induced by adrenaline were rare when the intramuscular route was used. PMID:26837822

Functional Connectivity of Resting Hemodynamic Signals in Submillimeter Orientation Columns of the Visual Cortex.

PubMed

Vasireddi, Anil K; Vazquez, Alberto L; Whitney, David E; Fukuda, Mitsuhiro; Kim, Seong-Gi

2016-09-07

Resting-state functional magnetic resonance imaging has been increasingly used for examining connectivity across brain regions. The spatial scale by which hemodynamic imaging can resolve functional connections at rest remains unknown. To examine this issue, deoxyhemoglobin-weighted intrinsic optical imaging data were acquired from the visual cortex of lightly anesthetized ferrets. The neural activity of orientation domains, which span a distance of 0.7-0.8 mm, has been shown to be correlated during evoked activity and at rest. We performed separate analyses to assess the degree to which the spatial and temporal characteristics of spontaneous hemodynamic signals depend on the known functional organization of orientation columns. As a control, artificial orientation column maps were generated. Spatially, resting hemodynamic patterns showed a higher spatial resemblance to iso-orientation maps than artificially generated maps. Temporally, a correlation analysis was used to establish whether iso-orientation domains are more correlated than orthogonal orientation domains. After accounting for a significant decrease in correlation as a function of distance, a small but significant temporal correlation between iso-orientation domains was found, which decreased with increasing difference in orientation preference. This dependence was abolished when using artificially synthetized orientation maps. Finally, the temporal correlation coefficient as a function of orientation difference at rest showed a correspondence with that calculated during visual stimulation suggesting that the strength of resting connectivity is related to the strength of the visual stimulation response. Our results suggest that temporal coherence of hemodynamic signals measured by optical imaging of intrinsic signals exists at a submillimeter columnar scale in resting state.

Hemodynamic correlates of nutritional indexes in heart failure.

PubMed

Horiuchi, Yu; Tanimoto, Shuzou; Okuno, Taishi; Aoki, Jiro; Yahagi, Kazuyuki; Sato, Yu; Tanaka, Tetsu; Koseki, Keita; Komiyama, Kota; Nakajima, Hiroyoshi; Hara, Kazuhiro; Tanabe, Kengo

2018-06-01

Malnutrition in heart failure (HF) is related to altered intestinal function, which could be due to hemodynamic changes. We investigated the usefulness of novel nutritional indexes in relation to hemodynamic parameters. We retrospectively analyzed 139 HF patients with reduced ejection fraction who underwent right heart catheterization. We investigated correlations between right side pressures and nutritional indexes, which include controlling nutritional (CONUT) score and geriatric nutritional risk index (GNRI). Receiver operating characteristic (ROC) curves were generated to investigate the prognostic accuracy of CONUT score and GNRI for a composite of death or HF hospitalization in 12 months. Logistic regression analysis was performed to investigate whether hemodynamic correlates were associated with malnutrition, which was defined based on CONUT sore or GNRI. Higher right side pressures were positively correlated with worse nutritional status according to CONUT score, but were negatively correlated with worse nutritional status according to GNRI. Area under ROC curve for the composite endpoint was 0.746 in CONUT score and 0.576 in GNRI. The composite endpoint occurred in 40% of CONUT score≥3 and in 11% of CONUT score<3 (p<0.001). These relationships were also investigated with GNRI (40% of GNRI<95 vs. 17% of GNRI≥95, p=0.002). In multivariate analysis, higher right atrial pressure was significantly associated with higher CONUT score, while no hemodynamic parameter was related to GNRI. CONUT score was associated with right side congestion, while no association between GNRI and right side congestion was noted. CONUT score had better predictive value than GNRI. Copyright © 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Hemodynamic effects of intravenous nicardipine in severely pre-eclamptic women with a hypertensive crisis.

PubMed

Cornette, J; Buijs, E A B; Duvekot, J J; Herzog, E; Roos-Hesselink, J W; Rizopoulos, D; Meima, M; Steegers, E A P

2016-01-01

Nicardipine permits rapid control of blood pressure in women with severe pre-eclampsia (PE) and hypertensive crisis. Our objective was to investigate its maternal and fetal hemodynamic effects. Ten severely pre-eclamptic pregnant women who required intravenous nicardipine for severe hypertension were included in this prospective observational trial. Maternal macrocirculation was assessed by transthoracic echocardiography. Maternal microcirculatory perfusion was examined sublingually with the sidestream dark field imaging technique. Fetal hemodynamics were assessed by Doppler examinations of the uteroplacental and fetal circulations. Maternal cardiac output, total vascular resistance, mitral E/A ratio and capillary heterogeneity index, uterine artery pulsatility index and fetal cerebroplacental ratio were considered primary outcomes. Paired measurements, obtained before administration of nicardipine infusion and after stabilization of blood pressure, were compared. Administration of nicardipine significantly reduced the mean arterial blood pressure (median difference, 26 mmHg; P = 0.002) and total vascular resistance (median difference, 791 dynes × s/cm(5) ; P = 0.002) in all included women. This induced a reflex tachycardia with consequent increase in cardiac output of 1.55 L/min (P  =  0.004). There were no significant changes in the other determinants of maternal or fetal hemodynamic parameters. Nicardipine effectively reduces blood pressure through selective afterload reduction that triggers an increase in cardiac output, without affecting maternal diastolic function, or microcirculatory, uteroplacental or fetal perfusion. This hemodynamic response is uniform and predictable. Fetomaternal cardiovascular profiling can be achieved by combining transthoracic echocardiography with obstetric Doppler. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Exercise capacity in the Bidirectional Glenn physiology: Coupling cardiac index, ventricular function and oxygen extraction ratio.

PubMed

Vallecilla, Carolina; Khiabani, Reza H; Trusty, Phillip; Sandoval, Néstor; Fogel, Mark; Briceño, Juan Carlos; Yoganathan, Ajit P

2015-07-16

In Bi-directional Glenn (BDG) physiology, the superior systemic circulation and pulmonary circulation are in series. Consequently, only blood from the superior vena cava is oxygenated in the lungs. Oxygenated blood then travels to the ventricle where it is mixed with blood returning from the lower body. Therefore, incremental changes in oxygen extraction ratio (OER) could compromise exercise tolerance. In this study, the effect of exercise on the hemodynamic and ventricular performance of BDG physiology was investigated using clinical patient data as inputs for a lumped parameter model coupled with oxygenation equations. Changes in cardiac index, Qp/Qs, systemic pressure, oxygen extraction ratio and ventricular/vascular coupling ratio were calculated for three different exercise levels. The patient cohort (n=29) was sub-grouped by age and pulmonary vascular resistance (PVR) at rest. It was observed that the changes in exercise tolerance are significant in both comparisons, but most significant when sub-grouped by PVR at rest. Results showed that patients over 2 years old with high PVR are above or close to the upper tolerable limit of OER (0.32) at baseline. Patients with high PVR at rest had very poor exercise tolerance while patients with low PVR at rest could tolerate low exercise conditions. In general, ventricular function of SV patients is too poor to increase CI and fulfill exercise requirements. The presented mathematical model provides a framework to estimate the hemodynamic performance of BDG patients at different exercise levels according to patient specific data. Published by Elsevier Ltd.

Dexmedetomidine could enhance surgical satisfaction in Trans-sphenoidal resection of pituitary adenoma.

PubMed

Salimi, Alireza; Sharifi, Guive; Bahrani, Houshang; Mohajerani, Seyed A; Jafari, Alireza; Safari, Farhad; Jalessi, Maryam; Mirkheshti, Alireza; Mottaghi, Kamran

2017-02-01

Excessive bleeding is an unwanted complication of trans-sphenoidal resection of pituitary adenoma due to increases in intracranial pressure (ICP) and hemodynamic instability. Dexmedetomidine (Dex) anα2-agonists is the drug of choice in intensive care units (ICU) and cardiac surgeries to control abrupt changes in hemodynamic. Severe cardiovascular responses occur during trans-sphenoidal resection (TSR) of the pituitary adenoma despite adequate depth of anesthesia. The aim of this paper was to determine the effect of Dexmedetomidine on bleeding as primary outcome, and surgeon's satisfaction and hemodynamic stability as secondary outcomes in patients undergoing trans-sphenoidal resection of pituitary adenoma. Total numbers of 60 patients between 18-65 years old and candidate for elective trans-sphenoidal resection of pituitary adenoma were randomLy allocated to two groups; Dexmedetomidine infusion (0.6µg/kg/hour) or normal saline infusion. Mean arterial pressure (MAP), heart rate (HR), dose of hypnotics and narcotics during surgery, bleeding, and surgeon's satisfaction were recorded. Propofol maintenance dose (µg/kg/min) and total Fentanyl use (µg) were significantly lower in Dex group compare to control group (P=0.01 and 0.003, respectively). Total bleeding amount during operation in Dex group was significantly lower than control group (P=0.012). Surgeon's satisfaction was significantly higher in Dex group at the end of surgery. MAP and heart rate throughout surgery were significantly lower in Dex group compare to control group (P=0.001). Dexmedetomidine infusion (0.6µg/kg/hour) could reduce bleeding and provide surgeon's satisfaction during trans-sphenoidal resection of pituitary adenoma.

Effects of Intravenous Patient-Controlled Sufentanil Analgesia and Music Therapy on Pain and Hemodynamics After Surgery for Lung Cancer: A Randomized Parallel Study.

PubMed

Wang, Yichun; Tang, Haoke; Guo, Qulian; Liu, Jingshi; Liu, Xiaohong; Luo, Junming; Yang, Wenqian

2015-11-01

Postoperative pain is caused by surgical injury and trauma; is stressful to patients; and includes a series of physiologic, psychological, and behavioral reactions. Effective postoperative analgesia helps improve postoperative pain, perioperative safety, and hospital discharge rates. This study aimed to observe the influence of postoperative intravenous sufentanil patient-controlled analgesia combined with music therapy versus sufentanil alone on hemodynamics and analgesia in patients with lung cancer. This was a randomized parallel study performed in 60 patients in American Society of Anesthesiologists class I or II undergoing lung cancer resection at the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University. Patients were randomly assigned to a music therapy (MT) group and a control (C) group. The MT group underwent preoperative and postoperative music intervention while the C group did not. Both groups received intravenous patient-controlled sufentanil analgesia. The primary outcome was the visual analogue scale (VAS) score at 24 hours after surgery. The secondary outcomes included hemodynamic changes (systolic blood pressure, diastolic blood pressure, heart rate), changes on the Self-Rating Anxiety Scale (SAS), total consumption of sufentanil, number of uses, sedation, and adverse effects. The postoperative sufentanil dose and analgesia frequency were recorded. Compared with the C group, the MT group had significantly lower VAS score, systolic and diastolic blood pressure, heart rate, and SAS score within 24 hours after surgery (p < 0.01). In addition, postoperative analgesia frequency and sufentanil dose were reduced in the MT group (p < 0.01). Combined music therapy and sufentanil improves intravenous patient-controlled analgesia effects compared with sufentanil alone after lung cancer surgery. Lower doses of sufentanil could be administered to more effectively improve patients' cardiovascular parameters.

A randomized controlled study to evaluate and compare Truview blade with Macintosh blade for laryngoscopy and intubation under general anesthesia.

PubMed

Timanaykar, Ramesh T; Anand, Lakesh K; Palta, Sanjeev

2011-04-01

The Truview EVO2™ laryngoscope is a recently introduced device with a unique blade that provides a magnified laryngeal view at 42° anterior reflected view. It facilitates visualization of the glottis without alignment of oral, pharyngeal, and tracheal axes. We compared the view obtained at laryngoscopy, intubating conditions and hemodynamic parameters of Truview with Macintosh blade. In prospective, randomized and controlled manner, 200 patients of ASA I and II of either sex (20-50 years), presenting for surgery requiring tracheal intubation, were assigned to undergo intubation using a Truview or Macintosh laryngoscope. Visualization of the vocal cord, ease of intubation, time taken for intubation, number of attempts, and hemodynamic parameters were evaluated. Truview provided better results for the laryngeal view using Cormack and Lehane grading, particularly in patients with higher airway Mallampati grading (P < 0.05). The time taken for intubation (33.06±5.6 vs. 23.11±57 seconds) was more with Truview than with Macintosh blade (P < 0.01). The Percentage of Glottic Opening (POGO) score was significantly higher (97.26±8) in Truview as that observed with Macintosh blade (83.70±21.5). Hemodynamic parameters increased after tracheal intubation from pre-intubation value (P < 0.05) in both the groups, but they were comparable amongst the groups. No postoperative adverse events were noted. Tracheal intubation using Truview blade provided consistently improved laryngeal view as compared to Macintosh blade without the need to align the oral, pharyngeal and tracheal axes, with equal attempts for successful intubation and similar changes in hemodynamics. However, the time taken for intubation was more with Truview.

Flow diverter effect of LVIS stent on cerebral aneurysm hemodynamics: a comparison with Enterprise stents and the Pipeline device.

PubMed

Wang, Chao; Tian, Zhongbin; Liu, Jian; Jing, Linkai; Paliwal, Nikhil; Wang, Shengzhang; Zhang, Ying; Xiang, Jianping; Siddiqui, Adnan H; Meng, Hui; Yang, Xinjian

2016-07-02

The aim of this study was to quantify the effect of the new Low-profile Visualized Intraluminal Support (LVIS®D) device and the difference of fluid diverting effect compared with the Pipeline device and the Enterprise stent using computational fluid dynamics (CFD). In this research, we simulated three aneurysms constructed from 3D digital subtraction angiography (DSA). The Enterprise, LVIS and the Pipeline device were virtually conformed to fit into the vessel lumen and placed across the aneurysm orifice. Computational fluid dynamics analysis was performed to compare the hemodynamic differences such as WSS, Velocity and Pressure among these stents. Control referred to the unstented model, the percentage of hemodynamic changes were all compared to Control. A single LVIS stent caused more wall shear stress reduction than double Enterprise stents (39.96 vs. 30.51 %) and velocity (23.13 vs. 18.64 %). Significant reduction in wall shear stress (63.88 %) and velocity (46.05 %) was observed in the double-LVIS stents. A single Pipeline showed less reduction in WSS (51.08 %) and velocity (37.87 %) compared with double-LVIS stent. The double-Pipeline stents resulted in the most reduction in WSS (72.37 %) and velocity (54.26 %). Moreover, the pressure increased with minuscule extent after stenting, compared with the unstented model. This is the first study analyzing flow modifications associated with LVIS stents. We found that the LVIS stent has certain hemodynamic effects on cerebral aneurysms: a single LVIS stent caused more flow reductions than the double-Enterprise stent but less than a Pipeline device. Nevertheless, the double-LVIS stent resulted in a better flow diverting effect than a Pipeline device.

Postoperative myocardial infarction documented by technetium pyrophosphate scan using single-photon emission computed tomography: Significance of intraoperative myocardial ischemia and hemodynamic control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, D.C.; Chung, F.; Burns, R.J.

The aim of this prospective study was to document postoperative myocardial infarction (PMI) by technetium pyrophosphate scan using single-photon emission computed tomography (TcPPi-SPECT) in 28 patients undergoing elective coronary bypass grafting (CABG). The relationships of intraoperative electrocardiographic myocardial ischemia, hemodynamic responses, and pharmacological requirements to this incidence of PMI were correlated. Radionuclide cardioangiography and TcPPi-SPECT were performed 24 h preoperatively and 48 h postoperatively. A standard high-dose fentanyl anesthetic protocol was used. Twenty-five percent of elective CABG patients were complicated with PMI, as documented by TcPPi-SPECT with an infarcted mass of 38.0 +/- 5.5 g. No significant difference in demographic,more » preoperative right and left ventricular function, number of coronary vessels grafted, or aortic cross-clamp time was observed between the PMI and non-PMI groups. The distribution of patients using preoperative beta-adrenergic blocking drugs or calcium channel blocking drugs was found to have no correlation with the outcome of PMI. As well, no significant differences in hemodynamic changes or pharmacological requirements were observed in the PMI and non-PMI groups during prebypass or postbypass periods, indicating careful intraoperative control of hemodynamic indices did not prevent the outcome of PMI in these patients. However, the incidence of prebypass ischemia was 39.3% and significantly correlated with the outcome of positive TcPPi-SPECT, denoting a 3.9-fold increased risk of developing PMI. Prebypass ischemic changes in leads II and V5 were shown to correlate with increased CPK-MB release (P less than 0.05) and tends to occur more frequently with lateral myocardial infarction.« less

Salt loading produces severe renal hemodynamic dysfunction independent of arterial pressure in spontaneously hypertensive rats.

PubMed

Matavelli, Luis C; Zhou, Xiaoyan; Varagic, Jasmina; Susic, Dinko; Frohlich, Edward D

2007-02-01

We have previously shown that salt excess has adverse cardiac effects in spontaneously hypertensive rats (SHR), independent of its increased arterial pressure; however, the renal effects have not been reported. In the present study we evaluated the role of three levels of salt loading in SHR on renal function, systemic and renal hemodynamics, and glomerular dynamics. At 8 wk of age, rats were given a 4% (n = 11), 6% (n = 9), or 8% (n = 11) salt-load diet for the ensuing 8 wk; control rats (n = 11) received standard chow (0.6% NaCl). Rats had weekly 24-h proteinuria and albuminuria quantified. At the end of salt loading, all rats had systemic and renal hemodynamics measured; glomerular dynamics were specially studied by renal micropuncture in the control, 4% and 6% salt-loaded rats. Proteinuria and albuminuria progressively increased by the second week of salt loading in the 6% and 8% salt-loaded rats. Mean arterial pressure increased minimally, and glomerular filtration rate decreased in all salt-loaded rats. The 6% and 8% salt-loaded rats demonstrated decreased renal plasma flow and increased renal vascular resistance and serum creatinine concentration. Furthermore, 4% and 6% salt-loaded rats had diminished single-nephron plasma flow and increased afferent and efferent arteriolar resistances; glomerular hydrostatic pressure also increased in the 6% salt-loaded rats. In conclusion, dietary salt loading as low as 4% dramatically deteriorated renal function, renal hemodynamics, and glomerular dynamics in SHR independent of a minimal further increase in arterial pressure. These findings support the concept of a strong independent causal relationship between salt excess and cardiovascular and renal injury.

Effects of Arginase Inhibition in Hypertensive Hyperthyroid Rats.

PubMed

Rodríguez-Gómez, Isabel; Manuel Moreno, Juan; Jimenez, Rosario; Quesada, Andrés; Montoro-Molina, Sebastian; Vargas-Tendero, Pablo; Wangensteen, Rosemary; Vargas, Félix

2015-12-01

This study analyzed the effects of chronic administration of N[omega]-hydroxy-nor-l-arginine (nor-NOHA), an inhibitor of arginase, on the hemodynamic, oxidative stress, morphologic, metabolic, and renal manifestations of hyperthyroidism in rats. Four groups of male Wistar rats were used: control, nor-NOHA-treated (10 mg/kg/day), thyroxine (T4)-treated (75 μg/rat/day), and thyroxine- plus nor-NOHA-treated rats. All treatments were maintained for 4 weeks. Body weight, tail systolic blood pressure (SBP), and heart rate (HR) were recorded weekly. Finally, morphologic, metabolic, plasma, and renal variables were measured. Arginase I and II protein abundance and arginase activity were measured in aorta, heart, and kidney. The T4 group showed increased arginase I and II protein abundance, arginase activity, SBP, HR, plasma nitrates/nitrites (NOx), brainstem and urinary isoprostanes, proteinuria and cardiac and renal hypertrophy in comparison to control rats. In hyperthyroid rats, chronic nor-NOHA prevented the increase in SBP and HR and decreased proteinuria in association with an increase in plasma NOx and a decrease in brainstem and urinary isoprostanes. In normal rats, nor-NOHA treatment did not significantly change any hemodynamic, morphologic, or renal variables. Acute nor-NOHA administration did not affect renal or systemic hemodynamic variables in normal or T4-treated rats. Hyperthyroidism in rats is associated with the increased expression and activity of arginase in aorta, heart, and kidney. Chronic arginase inhibition with nor-NOHA suppresses the characteristic hemodynamic manifestations of hyperthyroidism in association with a reduced oxidative stress. These results indicate an important role for arginase pathway alterations in the cardiovascular and renal abnormalities of hyperthyroidism. © American Journal of Hypertension, Ltd 2015. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Reduced left precentral regional responses in patients with major depressive disorder and history of suicide attempts.

PubMed

Tsujii, Noa; Mikawa, Wakako; Tsujimoto, Emi; Adachi, Toru; Niwa, Atsushi; Ono, Hisae; Shirakawa, Osamu

2017-01-01

Previous neuroimaging studies have revealed frontal and temporal functional abnormalities in patients with major depressive disorder (MDD) and a history of suicidal behavior. However, it is unknown whether multi-channel near-infrared spectroscopy (NIRS) signal changes among individuals with MDD are associated with a history of suicide attempts and a diathesis for suicidal behavior (impulsivity, hopelessness, and aggression). Therefore, we aimed to explore frontotemporal hemodynamic responses in depressed patients with a history of suicide attempts using 52-channel NIRS. We recruited 30 patients with MDD and a history of suicidal behavior (suicide attempters; SAs), 38 patient controls without suicidal behavior (non-attempters; NAs), and 40 healthy controls (HCs) matched by age, gender ratio, and estimated IQ. Regional hemodynamic responses during a verbal fluency task (VFT) were monitored using NIRS. Our results showed that severities of depression, impulsivity, aggression, and hopelessness were similar between SAs and NAs. Both patient groups had significantly reduced activation compared with HCs in the bilateral frontotemporal regions. Post hoc analyses revealed that SAs exhibited a smaller hemodynamic response in the left precentral gyrus than NAs and HCs. Furthermore, the reduced response in the left inferior frontal gyrus was negatively correlated with impulsivity level and hemodynamic responses in the right middle frontal gyrus were negatively associated with hopelessness and aggression in SAs but not in NAs and HCs. Our findings suggest that MDD patients with a history of suicide attempts demonstrate patterns of VFT-induced NIRS signal changes different from those demonstrated by individuals without a history of suicidal behaviors, even in cases where clinical symptoms are similar. NIRS has a relatively high time resolution, which may help visually differentiate SAs from NAs.

Xenon as an Adjuvant to Propofol Anesthesia in Patients Undergoing Off-Pump Coronary Artery Bypass Graft Surgery: A Pragmatic Randomized Controlled Clinical Trial.

PubMed

Al Tmimi, Layth; Devroe, Sarah; Dewinter, Geertrui; Van de Velde, Marc; Poortmans, Gert; Meyns, Bart; Meuris, Bart; Coburn, Mark; Rex, Steffen

2017-10-01

Xenon was shown to cause less hemodynamic instability and reduce vasopressor needs during off-pump coronary artery bypass (OPCAB) surgery when compared with conventionally used anesthetics. As xenon exerts its organ protective properties even in subanesthetic concentrations, we hypothesized that in patients undergoing OPCAB surgery, 30% xenon added to general anesthesia with propofol results in superior hemodynamic stability when compared to anesthesia with propofol alone. Fifty patients undergoing elective OPCAB surgery were randomized to receive general anesthesia with 30% xenon adjuvant to a target-controlled infusion of propofol or with propofol alone. The primary end point was the total intraoperative dose of norepinephrine required to maintain an intraoperative mean arterial pressure >70 mm Hg. Secondary outcomes included the perioperative cardiorespiratory profile and the incidence of adverse and serious adverse events. Adding xenon to propofol anesthesia resulted in a significant reduction of norepinephrine required to attain the predefined hemodynamic goals (cumulative intraoperative dose: median [interquartile range]: 370 [116-570] vs 840 [335-1710] µg, P = .001). In the xenon-propofol group, significantly less propofol was required to obtain a similar depth of anesthesia as judged by clinical signs and the bispectral index (propofol effect site concentration [mean ± SD]: 1.8 ± 0.5 vs 2.8 ± 0.3 mg, P≤ .0001). Moreover, the xenon-propofol group required significantly less norepinephrine during the first 24 hours on the intensive care unit (median [interquartile range]: 1.5 [0.1-7] vs 5 [2-8] mg, P = .048). Other outcomes and safety parameters were similar in both groups. Thirty percent xenon added to propofol anesthesia improves hemodynamic stability by decreasing norepinephrine requirements in patients undergoing OPCAB surgery.

Randomized controlled study comparing the hemodynamic response to laryngoscopy and endotracheal intubation with McCoy, Macintosh, and C-MAC laryngoscopes in adult patients

PubMed Central

Buhari, Faiza Sulaiman; Selvaraj, Venkatesh

2016-01-01

Background and Aims: Earlier studies have shown that the type of laryngoscope blade influences the degree of hemodynamic response to endotracheal intubation. The aim of the study was to evaluate the hemodynamic response to oral endotracheal intubation with C-MAC laryngoscopy and McCoy laryngoscopy compared to that of Macintosh laryngoscopy in adult patients under general anesthesia. Material and Methods: This is a prospective randomized parallel group study. Ninety American Society of Anesthesiologists I patients were randomly allotted into three groups. Group A – Macintosh laryngoscopy (control group). Group B – laryngoscopy with McCoy laryngoscope. Group C – laryngoscopy with C-MAC video laryngoscope. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were monitored at baseline (just before induction), just before intubation (T0), 1 min (T1), 3 min (T3), 5 min (T5), and 10 min (T10) after intubation. Intergroup comparison of study parameters was done by unpaired sample t-test for normal data and Mann-Whitney U-test for skewed data. For within-group comparison, the repeated measures of ANOVA for normal data and Friedman followed by Wilcoxon signed rank test for skewed data were performed. Results: In C-MAC group, the HR was significantly higher than the Macintosh group at 3 min after intubation, whereas SBP, DBP, and MAP were significantly higher at 1 min. McCoy group showed a similar response compared to Macintosh group at all time intervals. Conclusion: C-MAC video laryngoscope has a comparatively greater hemodynamic response than Macintosh laryngoscope. PMID:28096584

A randomized controlled study to evaluate and compare Truview blade with Macintosh blade for laryngoscopy and intubation under general anesthesia

PubMed Central

Timanaykar, Ramesh T; Anand, Lakesh K; Palta, Sanjeev

2011-01-01

Background: The Truview EVO2™ laryngoscope is a recently introduced device with a unique blade that provides a magnified laryngeal view at 42° anterior reflected view. It facilitates visualization of the glottis without alignment of oral, pharyngeal, and tracheal axes. We compared the view obtained at laryngoscopy, intubating conditions and hemodynamic parameters of Truview with Macintosh blade. Materials and Methods: In prospective, randomized and controlled manner, 200 patients of ASA I and II of either sex (20–50 years), presenting for surgery requiring tracheal intubation, were assigned to undergo intubation using a Truview or Macintosh laryngoscope. Visualization of the vocal cord, ease of intubation, time taken for intubation, number of attempts, and hemodynamic parameters were evaluated. Results: Truview provided better results for the laryngeal view using Cormack and Lehane grading, particularly in patients with higher airway Mallampati grading (P < 0.05). The time taken for intubation (33.06±5.6 vs. 23.11±57 seconds) was more with Truview than with Macintosh blade (P < 0.01). The Percentage of Glottic Opening (POGO) score was significantly higher (97.26±8) in Truview as that observed with Macintosh blade (83.70±21.5). Hemodynamic parameters increased after tracheal intubation from pre-intubation value (P < 0.05) in both the groups, but they were comparable amongst the groups. No postoperative adverse events were noted. Conclusion: Tracheal intubation using Truview blade provided consistently improved laryngeal view as compared to Macintosh blade without the need to align the oral, pharyngeal and tracheal axes, with equal attempts for successful intubation and similar changes in hemodynamics. However, the time taken for intubation was more with Truview. PMID:21772680

Effect of high altitude exposure on the hemodynamics of the bidirectional Glenn physiology: modeling incremented pulmonary vascular resistance and heart rate.

PubMed

Vallecilla, Carolina; Khiabani, Reza H; Sandoval, Néstor; Fogel, Mark; Briceño, Juan Carlos; Yoganathan, Ajit P

2014-06-03

The considerable blood mixing in the bidirectional Glenn (BDG) physiology further limits the capacity of the single working ventricle to pump enough oxygenated blood to the circulatory system. This condition is exacerbated under severe conditions such as physical activity or high altitude. In this study, the effect of high altitude exposure on hemodynamics and ventricular function of the BDG physiology is investigated. For this purpose, a mathematical approach based on a lumped parameter model was developed to model the BDG circulation. Catheterization data from 39 BDG patients at stabilized oxygen conditions was used to determine baseline flows and pressures for the model. The effect of high altitude exposure was modeled by increasing the pulmonary vascular resistance (PVR) and heart rate (HR) in increments up to 80% and 40%, respectively. The resulting differences in vascular flows, pressures and ventricular function parameters were analyzed. By simultaneously increasing PVR and HR, significant changes (p <0.05) were observed in cardiac index (11% increase at an 80% PVR and 40% HR increase) and pulmonary flow (26% decrease at an 80% PVR and 40% HR increase). Significant increase in mean systemic pressure (9%) was observed at 80% PVR (40% HR) increase. The results show that the poor ventricular function fails to overcome the increased preload and implied low oxygenation in BDG patients at higher altitudes, especially for those with high baseline PVRs. The presented mathematical model provides a framework to estimate the hemodynamic performance of BDG patients at different PVR increments. Copyright © 2014 Elsevier Ltd. All rights reserved.

Elevation of Plasma Cell-Free Hemoglobin in Pulmonary Arterial Hypertension

PubMed Central

Janz, David R.; Austin, Eric D.; Bastarache, Julie A.; Wheeler, Lisa A.; Ware, Lorraine B.; Hemnes, Anna R.

2014-01-01

BACKGROUND: Cell-free hemoglobin (CFH) is a potent nitric oxide scavenger associated with poor outcomes in several diseases. Pulmonary arterial hypertension (PAH) is characterized by reduced nitric oxide availability. We hypothesized that CFH would be elevated in PAH and would associate with hemodynamics and clinical outcomes. METHODS: We measured CFH in 200 consecutively evaluated patients with PAH, 16 unaffected bone morphogenetic receptor protein type 2 (BMPR2) mutation carriers, 19 healthy subjects, and 29 patients with pulmonary venous hypertension (PVH). CFH values were tested for association with hemodynamics, time to hospitalization, and death. RESULTS: CFH was elevated in patients with PAH and BMPR2 carriers compared with healthy subjects and patients with PVH (P ≤ .01 all comparisons). There were no differences in CFH across PAH subtypes. CFH modestly correlated with mean pulmonary artery pressure (ρ = 0.16, P = .03) and pulmonary vascular resistance (ρ = 0.21, P = .01) and inversely with cardiac index (ρ = −0.18, P = .02) in patients with PAH. CFH was not associated with hemodynamic response to nitric oxide or death. Patients with the highest CFH levels had increased risk of PAH-related hospitalization when adjusted for age, sex, and PAH cause (hazard ratio, 1.69; 95% CI ,1.08-2.66; P = .02). CONCLUSIONS: CFH is elevated in patients with PAH and BMPR2 carriers compared with healthy subjects and patients with PVH. Elevated CFH levels are independently associated with an increased risk of hospitalization. Further study is required to understand the mechanism of CFH elevation and the potential pathologic contribution of CFH in PAH. PMID:24945582

Hemodynamic and metabolic effects of para- versus intraaortic counterpulsatile circulation supports.

PubMed

Lu, Pong-Jeu; Lin, Pao-Yen; Yang, Chi-Fu Jeffrey; Hung, Chun-Hao; Chan, Ming-Yao; Hsu, Tzu-Cheng

2011-01-01

Despite the success of intraaortic balloon counterpulsation, data on physiologic indices and optimal inflation/deflation timing control of chronic counterpulsation devices are unclear. This study explored the acute hemodynamic and metabolic efficacy of a novel 40-ml stroke volume paraaortic blood pump (PABP) versus a standard intraaortic balloon pump (IABP). Acute porcine model was used with eight pigs randomly divided into PABP (n = 4) and IABP (n = 4) groups. Hemodynamic and metabolic measurements were obtained with and without mechanical assistance. In one pig, the inflation/deflation control was adjusted to different settings, with corresponding performance indices measured. The PABP significantly improved classical counterpulsation indices (p ≤ 0.05) and achieved an average beneficial effect on these indices 1.5-3.5 times greater than that of the IABP. Classical metabolic indices (tension time index and endocardial viability ratio [EVR]), and indices new to chronic counterpulsation research (coronary perfusion, left ventricular stroke work (SW), and a newly derived EVR) were also used in assessment. Both IABP assistance and PABP assistance improved these physiologic indices, with a trend toward PABP superiority in reducing left ventricular SW (p = 0.08). An optimal PABP deflation timing occurs during systole (25 milliseconds after the R-wave) and can minimize coronary regurgitation.

Estimation of Filling and Afterload Conditions by Pump Intrinsic Parameters in a Pulsatile Total Artificial Heart.

PubMed

Cuenca-Navalon, Elena; Laumen, Marco; Finocchiaro, Thomas; Steinseifer, Ulrich

2016-07-01

A physiological control algorithm is being developed to ensure an optimal physiological interaction between the ReinHeart total artificial heart (TAH) and the circulatory system. A key factor for that is the long-term, accurate determination of the hemodynamic state of the cardiovascular system. This study presents a method to determine estimation models for predicting hemodynamic parameters (pump chamber filling and afterload) from both left and right cardiovascular circulations. The estimation models are based on linear regression models that correlate filling and afterload values with pump intrinsic parameters derived from measured values of motor current and piston position. Predictions for filling lie in average within 5% from actual values, predictions for systemic afterload (AoPmean , AoPsys ) and mean pulmonary afterload (PAPmean ) lie in average within 9% from actual values. Predictions for systolic pulmonary afterload (PAPsys ) present an average deviation of 14%. The estimation models show satisfactory prediction and confidence intervals and are thus suitable to estimate hemodynamic parameters. This method and derived estimation models are a valuable alternative to implanted sensors and are an essential step for the development of a physiological control algorithm for a fully implantable TAH. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Implantable Hemodynamic Monitoring for Heart Failure Patients.

PubMed

Abraham, William T; Perl, Leor

2017-07-18

Rates of heart failure hospitalization remain unacceptably high. Such hospitalizations are associated with substantial patient, caregiver, and economic costs. Randomized controlled trials of noninvasive telemedical systems have failed to demonstrate reduced rates of hospitalization. The failure of these technologies may be due to the limitations of the signals measured. Intracardiac and pulmonary artery pressure-guided management has become a focus of hospitalization reduction in heart failure. Early studies using implantable hemodynamic monitors demonstrated the potential of pressure-based heart failure management, whereas subsequent studies confirmed the clinical utility of this approach. One large pivotal trial proved the safety and efficacy of pulmonary artery pressure-guided heart failure management, showing a marked reduction in heart failure hospitalizations in patients randomized to active pressure-guided management. "Next-generation" implantable hemodynamic monitors are in development, and novel approaches for the use of this data promise to expand the use of pressure-guided heart failure management. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Hemodynamic Effects of Midodrine After Space Flight in Astronauts Without Orthostatic Hypotension

NASA Technical Reports Server (NTRS)

Platts, Steven H.; Ziegler, Michael G.; Waters, Wendy W.; Meck, Janice V.

2006-01-01

Orthostatic hypotension and presyncope are common and potentially serious risks for astronauts returning from space. Susceptible subjects fail to generate an adequate adrenergic response to upright posture. The -1 adrenergic agonist, midodrine, may be an effective countermeasure. We tested the hypothesis that midodrine would have no negative hemodynamic effect on healthy astronauts returning from space. Five male astronauts participated in preflight and postflight tilt testing on a control flight as well as on the test flights, where midodrine (10 mg, orally) was administered after landing, approximately 1 hour before testing. None of these astronauts exhibited orthostatic hypotension or presyncope before or after either flight. Midodrine did not cause any untoward reactions in these subjects before or after flight, in fact a modest beneficial effect was seen on postflight tachycardia (p=0.036). These data show that midodrine protected against post-spaceflight increases in heart rate, without having any adverse hemodynamic effects on non-presyncopal, male astronauts. Among these subjects, midodrine was a safe cardiovascular countermeasure.

The capillary bed offers the largest hemodynamic resistance to the cortical blood supply

PubMed Central

Gould, Ian Gopal; Tsai, Philbert; Kleinfeld, David

2016-01-01

The cortical angioarchitecture is a key factor in controlling cerebral blood flow and oxygen metabolism. Difficulties in imaging the complex microanatomy of the cortex have so far restricted insight about blood flow distribution in the microcirculation. A new methodology combining advanced microscopy data with large scale hemodynamic simulations enabled us to quantify the effect of the angioarchitecture on the cerebral microcirculation. High-resolution images of the mouse primary somatosensory cortex were input into with a comprehensive computational model of cerebral perfusion and oxygen supply ranging from the pial vessels to individual brain cells. Simulations of blood flow, hematocrit and oxygen tension show that the wide variation of hemodynamic states in the tortuous, randomly organized capillary bed is responsible for relatively uniform cortical tissue perfusion and oxygenation. Computational analysis of microcirculatory blood flow and pressure drops further indicates that the capillary bed, including capillaries adjacent to feeding arterioles (d < 10 µm), are the largest contributors to hydraulic resistance. PMID:27780904

Novel Goal-Directed Hemodynamic Optimization Therapy Based on Major Vasopressor during Corrective Cardiac Surgery in Patients with Severe Pulmonary Arterial Hypertension: A Pilot Study.

PubMed

Li, Shuwen; Ma, Qing; Yang, Yanwei; Lu, Jiakai; Zhang, Zhiquan; Jin, Mu; Cheng, Weiping

2016-12-22

Pulmonary arterial hypertension (PAH) is a common and fatal complication of congenital heart disease (CHD). PAH-CHD increases the risk for postoperative complications. Recent evidence suggests that perioperative goal-directed hemodynamic optimization therapy (GDHOT) significantly improves outcomes in surgery patients. Standard GDHOT is based on major solution volume, vasodilators and inotropic therapy, while novel GDHOT is based on major vasopressor and inotropic therapy. Therefore, we tested whether standard or novel GDHOT improves surgical outcomes in PAH-CHD patients. Forty PAH-CHD patients with a ventricular septal defect (VSD) and mean pulmonary arterial pressure (mPAP) >50 mmHg, who were scheduled for corrective surgery, were randomly assigned to 2 groups: SG (study group, n = 20) and CG (control group, n = 20). SG patients received perioperative hemodynamic therapy guided by novel GDHOT, while CG patients received standard GDHOT. Outcome data were recorded up to 28 days postoperatively. Ventilator time, length of ICU stay, and mortality were the primary endpoints. There were no significant differences in preoperative data, surgical procedure, and hospital mortality rates between the 2 groups. Time of mechanical ventilation and length of ICU stay were significantly shorter in SG patients compared to CG patients (P < .05, n = 20). Patients in SG showed a significantly increased systemic vascular resistance index and decreased cardiac index, but no change in pulmonary vascular resistance index at 12 and 24 hours after surgery compared to the controls (P < .05). Patients in SG had significantly decreased PAP, pulmonary arterial pressure/systemic arterial pressure (Pp/Ps), and RVSWI (right ventricular stroke work index) at 12 and 24 hours after surgery (P < .05, respectively). Patients in SG also showed significantly decreased central venous pressure at 4, 12, and 24 hours after surgery compared to those treated with standard protocol (P < .05). Our study provides clinical evidence that perioperative goal-directed hemodynamic optimization therapy based on major vasopressor is associated with reduced duration of postoperative respiratory support, and length of ICU stay in PAH-CHD patients undergoing elective surgery. These outcomes, then, may be linked to improved hemodynamics and preservation of right ventricular dynamic function.

Rifaximin has no effect on hemodynamics in decompensated cirrhosis: A randomized, double-blind, placebo-controlled trial.

PubMed

Kimer, Nina; Pedersen, Julie Steen; Busk, Troels Malte; Gluud, Lise Lotte; Hobolth, Lise; Krag, Aleksander; Møller, Søren; Bendtsen, Flemming

2017-02-01

Decompensated cirrhosis is characterized by disturbed systemic and splanchnic hemodynamics. Bacterial translocation from the gut is considered the key driver in this process. Intestinal decontamination with rifaximin may improve hemodynamics. This double-blind, randomized, controlled trial (clinicaltrials.gov, NCT01769040) investigates the effects of rifaximin on hemodynamics, renal function, and vasoactive hormones. We randomized 54 stable outpatients with cirrhosis and ascites to rifaximin 550 mg twice a day (n = 36) or placebo twice a day (n = 18). Forty-five patients were male, mean age 56 years (±8.4), average Child score 8.3 (±1.3), and Model for End-Stage Liver Disease score 11.7 (±3.9). Measurements of hepatic venous pressure gradient, cardiac output, and systemic vascular resistance were made at baseline and after 4 weeks. The glomerular filtration rate and plasma renin, noradrenaline, lipopolysaccharide binding protein, troponin T, and brain natriuretic peptide levels were measured. Rifaximin had no effect on hepatic venous pressure gradient, mean 16.8 ± 3.8 mm Hg at baseline versus 16.6 ± 5.3 mm Hg at follow-up, compared to the placebo, mean 16.4 ± 4 mm Hg at baseline versus 16.3 ± 4.4 mm Hg at follow-up, P = 0.94. No effect was found on cardiac output, mean 6.9 ± 1.7 L/min at baseline versus 6.9 ± 2.3 L/min at follow-up, compared to placebo, mean 6.6 ± 1.9 L/min at baseline compared to 6.5 ±2.1 L/min at follow-up, P = 0.66. No effects on the glomerular filtration rate, P = 0.14, or vasoactive hormones were found. Subgroup analyses on patients with increased lipopolysaccharide binding protein and systemic vascular resistance below the mean (1,011 dynes × s/cm 5 ) revealed no effect of rifaximin. Four weeks of treatment with rifaximin did not reduce the hepatic venous pressure gradient or improve systemic hemodynamics in patients with cirrhosis and ascites; rifaximin did not affect glomerular filtration rate or levels of vasoactive hormones. (Hepatology 2017;65:592-603). © 2016 by the American Association for the Study of Liver Diseases.

The effect of dim light at night on cerebral hemodynamic oscillations during sleep: A near-infrared spectroscopy study.

PubMed

Kim, Tae-Joon; Lee, Byeong Uk; Sunwoo, Jun-Sang; Byun, Jung-Ick; Moon, Jangsup; Lee, Soon-Tae; Jung, Keun-Hwa; Chu, Kon; Kim, Manho; Lim, Jong-Min; Lee, Eunil; Lee, Sang Kun; Jung, Ki-Young

2017-01-01

Recent studies have reported that dim light at night (dLAN) is associated with risks of cardiovascular complications, such as hypertension and carotid atherosclerosis; however, little is known about the underlying mechanism. Here, we evaluated the effect of dLAN on the cerebrovascular system by analyzing cerebral hemodynamic oscillations using near-infrared spectroscopy (NIRS). Fourteen healthy male subjects underwent polysomnography coupled with cerebral NIRS. The data collected during sleep with dim light (10 lux) were compared with those collected during sleep under the control dark conditions for the sleep structure, cerebral hemodynamic oscillations, heart rate variability (HRV), and their electroencephalographic (EEG) power spectrum. Power spectral analysis was applied to oxy-hemoglobin concentrations calculated from the NIRS signal. Spectral densities over endothelial very-low-frequency oscillations (VLFOs) (0.003-0.02 Hz), neurogenic VLFOs (0.02-0.04 Hz), myogenic low-frequency oscillations (LFOs) (0.04-0.15 Hz), and total LFOs (0.003-0.15 Hz) were obtained for each sleep stage. The polysomnographic data revealed an increase in the N2 stage under the dLAN conditions. The spectral analysis of cerebral hemodynamics showed that the total LFOs increased significantly during slow-wave sleep (SWS) and decreased during rapid eye movement (REM) sleep. Specifically, endothelial (median of normalized value, 0.46 vs. 0.72, p = 0.019) and neurogenic (median, 0.58 vs. 0.84, p = 0.019) VLFOs were enhanced during SWS, whereas endothelial VLFOs (median, 1.93 vs. 1.47, p = 0.030) were attenuated during REM sleep. HRV analysis exhibited altered spectral densities during SWS induced by dLAN, including an increase in very-low-frequency and decreases in low-frequency and high-frequency ranges. In the EEG power spectral analysis, no significant difference was detected between the control and dLAN conditions. In conclusion, dLAN can disturb cerebral hemodynamics via the endothelial and autonomic systems without cortical involvement, predominantly during SWS, which might represent an underlying mechanism of the increased cerebrovascular risk associated with light exposure during sleep.

Duplex scanning diagnosis of internal carotid artery dissections. A case control study.

PubMed

Alecu, C; Fortrat, J O; Ducrocq, X; Vespignani, H; de Bray, J M

2007-01-01

The reliability of duplex scanning (DS) for the diagnosis of internal carotid artery dissections (ICAD) is not clear. Nine DS signs known to be suggestive for the diagnosis of ICAD were compared between 70 patients with ICAD and 70 matched patients without dissection. Visible internal tapering occlusion, regular eccentric narrowing channel, ectasia beyond the carotid bulb, resistive index asymmetry, blood flow slowdown, ophthalmic artery blood flow inversion, and biphasic flow are more frequent in cases than in controls (p < 0.001). Atheroma plaques were absent in 80% of ICAD. When DS direct signs and hemodynamic signs were studied, sensitivity was 90% and specificity 60%. Diagnosis of ICAD by DS could be improved if direct signs were combined with hemodynamic signs, giving a high sensitivity and a rather good specificity. Copyright 2007 S. Karger AG, Basel.

Ceftazidime improves hemodynamics and oxygenation in ovine smoke inhalation injury and septic shock.

PubMed

Maybauer, Marc O; Maybauer, Dirk M; Fraser, John F; Traber, Lillian D; Westphal, Martin; Cox, Robert A; Huda, Ruksana; Nakano, Yoshimitsu Y; Enkhbaatar, Perenlei; Hawkins, Hal K; Herndon, David N; Traber, Daniel L

2007-07-01

To investigate ceftazidime in acute lung injury (ALI) and sepsis. Prospective, randomized, controlled animal study in an investigational ICU at a university hospital. Eighteen female Merino sheep were prepared for chronic study and subjected to smoke inhalation and septic challenge according to an established protocol. Whereas global hemodynamics and oxygenation remained stable in sham animals (no injury, no treatment), the injury contributed to a hypotensive-hyperdynamic circulation in the control group (smoke inhalation and sepsis, no treatment), as indicated by a significant increase in cardiac index) and heart rate and a drop in mean arterial pressure. Treatment with ceftazidime (smoke inhalation and sepsis, treatment group) stabilized cardiac index and heart rate and attenuated the decrease in mean arterial pressure. The deterioration in PaO2/FiO2 ratio and pulmonary shunt fraction (Qs/Qt) was significantly delayed and blunted by ceftazidime. At 24 h after injury a significant increase in airway obstruction scores of bronchi and bronchioles in both injured groups was observed. Ceftazidime significantly reduced airway obstruction vs. control animals. Whereas plasma nitrate/nitrite levels increased similarly in the two injured groups, lung 3-nitrotyrosine content remained at the baseline level in the ceftazidime group. In ovine lung injury ceftazidime improves global hemodynamics and oxygenation not only by bacterial clearance but also via reduction in toxic nitrogen species such as 3-nitrotyrosine. Therefore ceftazidime appears as a clinically relevant adjunct in the common setting of sepsis-associated lung injury.

Effects of sounds generated by a dental turbine and a stream on regional cerebral blood flow and cardiovascular responses.

PubMed

Mishima, Riho; Kudo, Takumu; Tsunetsugu, Yuko; Miyazaki, Yoshifumi; Yamamura, Chie; Yamada, Yoshiaki

2004-09-01

Effects of sound generated by a dental turbine and a small stream (murmur) and the effects of no sound (null, control) on heart rate, systolic and diastolic blood pressure, and hemodynamic changes (oxygenated, deoxygenated, and total hemoglobin concentrations) in the frontal cortex were measured in 18 young volunteers. Questionnaires completed by the volunteers were also evaluated. Near-infrared spectroscopy and the Finapres technique were employed to measure hemodynamic and vascular responses, respectively. The subjects assessed the murmur, null, and turbine sounds as "pleasant," "natural," and "unpleasant," respectively. Blood pressures changed in response to the murmur, null, and turbine sound stimuli as expected: lower than the control level, unchanged, and higher than the control level, respectively. Mean blood pressure values tended to increase gradually over the recording time even during the null sound stimulation, possibly because of the recording environment. Oxygenated hemoglobin concentrations decreased drastically in response to the dental turbine sound, while deoxygenated hemoglobin concentrations remained unchanged and thus total hemoglobin concentrations decreased (due to the decreased oxygenated hemoglobin concentrations). Hemodynamic responses to the murmuring sound and the null sound were slight or unchanged, respectively. Surprisingly, heart rate measurements remained fairly stable in response to the stimulatory noises. In conclusion, we demonstrate here that sound generated by a dental turbine may affect cerebral blood flow and metabolism as well as autonomic responses. Copyright 2004 The Society of the Nippon Dental University

Mathematical modeling of renal hemodynamics in physiology and pathophysiology.

PubMed

Sgouralis, Ioannis; Layton, Anita T

2015-06-01

In addition to the excretion of metabolic waste and toxin, the kidney plays an indispensable role in regulating the balance of water, electrolyte, acid-base, and blood pressure. For the kidney to maintain proper functions, hemodynamic control is crucial. In this review, we describe representative mathematical models that have been developed to better understand the kidney's autoregulatory processes. We consider mathematical models that simulate glomerular filtration, and renal blood flow regulation by means of the myogenic response and tubuloglomerular feedback. We discuss the extent to which these modeling efforts have expanded the understanding of renal functions in health and disease. Copyright © 2015 Elsevier Inc. All rights reserved.

Optical mapping of the brain activity in children with Down's syndrome

NASA Astrophysics Data System (ADS)

Yuan, Zhen; Lu, Fengmei

2018-02-01

Down's syndrome (DS) has been shown to be associated with many neurological complications, including cognitive deficits, seizures, early-onset dementia that resembles Alzheimer's disease, and neurological complications of systemic disorders. DS patients show to have poor performance in executive functions (EF) and fine motor skills. In this study, we examined the brain hemodynamic responses and brain activation patterns of DS children during the completion of EF tasks. Revealing its neural mechanism of DS is not only able to contribute to the early intervention of this children with DS, but also increase understanding of developmental cascades in childhood.

Optimization of ADME Properties for Sulfonamides Leading to the Discovery of a T-Type Calcium Channel Blocker, ABT-639

PubMed Central

2015-01-01

The discovery of a novel peripherally acting and selective Cav3.2 T-type calcium channel blocker, ABT-639, is described. HTS hits 1 and 2, which have poor metabolic stability, were optimized to obtain 4, which has improved stability and oral bioavailability. Modification of 4 to further improve ADME properties led to the discovery of ABT-639. Following oral administration, ABT-639 produces robust antinociceptive activity in experimental pain models at doses that do not significantly alter psychomotor or hemodynamic function in the rat. PMID:26101566

Optimization of ADME Properties for Sulfonamides Leading to the Discovery of a T-Type Calcium Channel Blocker, ABT-639.

PubMed

Zhang, Qingwei; Xia, Zhiren; Joshi, Shailen; Scott, Victoria E; Jarvis, Michael F

2015-06-11

The discovery of a novel peripherally acting and selective Cav3.2 T-type calcium channel blocker, ABT-639, is described. HTS hits 1 and 2, which have poor metabolic stability, were optimized to obtain 4, which has improved stability and oral bioavailability. Modification of 4 to further improve ADME properties led to the discovery of ABT-639. Following oral administration, ABT-639 produces robust antinociceptive activity in experimental pain models at doses that do not significantly alter psychomotor or hemodynamic function in the rat.

Acute effects of power and resistance exercises on hemodynamic measurements of older women

PubMed Central

Coelho-Júnior, Hélio José; Irigoyen, Maria-Cláudia; Aguiar, Samuel da Silva; Gonçalves, Ivan de Oliveira; Câmara, Niels Olsen Saraiva; Cenedeze, Marco Antonio; Asano, Ricardo Yukio; Rodrigues, Bruno; Uchida, Marco Carlos

2017-01-01

Purpose The purpose of this study was to compare the acute effects of resistance training (RT) and power training (PT) on the hemodynamic parameters and nitric oxide (NO) bioavailability of older women. Materials and methods A randomized experimental design was used in this study. Twenty-one older women (age: 67.1±4.6 years; body mass index: 28.03±4.9 kg/m2; systolic blood pressure: 135.1±21.1 mmHg) were recruited to participate in this study. Volunteers were randomly allocated into PT, RT, and control session (CS) groups. The PT and RT groups underwent a single session of physical exercise equalized by training volume, characterized by 3 sets of 8–10 repetitions in 8 different exercises. However, RT group performed exercise at a higher intensity (difficult) than PT (moderate) group. On the other hand, concentric contractions were faster in PT group than in RT group. Hemodynamic parameters and saliva samples (for NO quantification) were collected before and during an hour after exercise completion. Results Results demonstrated post-exercise hypotension during 35 minutes in the PT when compared to rest period (P=0.001). In turn, RT showed decreased heart rate and double product (P<0.001) during the whole evaluation period after exercise completion compared with the rest period. NO levels increased in the PT and RT during the whole evaluation period in relation to rest period. However, there were no differences between PT, RT, and CS regarding hemodynamic and NO evaluations. Conclusion Data indicate that an acute session of power and resistance exercise can be effective to cause beneficial changes on hemodynamic parameters and NO levels in older women. PMID:28744114

Chronologic Evaluation of Cerebral Hemodynamics by Dynamic Susceptibility Contrast Magnetic Resonance Imaging After Indirect Bypass Surgery for Moyamoya Disease.

PubMed

Ishii, Yosuke; Tanaka, Yoji; Momose, Toshiya; Yamashina, Motoshige; Sato, Akihito; Wakabayashi, Shinichi; Maehara, Taketoshi; Nariai, Tadashi

2017-12-01

Although indirect bypass surgery is an effective treatment option for patients with ischemic-onset moyamoya disease (MMD), the time point after surgery at which the patient's hemodynamic status starts to improve and the time point at which the improvement reaches a maximum have not been known. The objective of the present study is to evaluate the hemodynamic status time course after indirect bypass surgery for MMD, using dynamic susceptibility contrast-magnetic resonance imaging (DSC-MRI). We retrospectively analyzed the cases of 25 patients with MMD (37 sides; mean age, 14.7 years; range, 3-36 years) who underwent indirect bypass surgery and repeated DSC-MRI measurement within 6 months after the operation. The difference in the mean transit time (MTT) between the target regions and the control region (cerebellum) was termed the MTT delay, and we measured the MTT delay's chronologic changes after surgery. The postoperative MTT delay was 1.81 ± 1.16 seconds within 1 week after surgery, 1.57 ± 1.01 at weeks 1-2, 1.55 ± 0.68 at weeks 2-4, 1.32 ± 0.68 at months 1-2, 0.95 ± 0.32 at months 2-3, and 0.77 ± 0.33 at months 3-6. Compared with the preoperative value (2.11 ± 0.98 seconds), the MTT delay decreased significantly from 2 to 4 weeks after surgery (P < 0.05). The amelioration of cerebral hemodynamics by indirect bypass surgery began soon after surgery and gradually reached a maximum at 3 months after surgery. DSC-MRI detected small changes in hemodynamic improvement, which are suspected to be caused by the initiation of angiogenesis and arteriogenesis in the early postoperative period. Copyright © 2017. Published by Elsevier Inc.

Dissociation of hemodynamic and electrocardiographic indexes of myocardial ischemia in pigs with hibernating myocardium and sudden cardiac death.

PubMed

Pizzuto, Matthew F; Suzuki, Gen; Banas, Michael D; Heavey, Brendan; Fallavollita, James A; Canty, John M

2013-06-15

Many survivors of sudden cardiac death (SCD) have normal global ventricular function and severe coronary artery disease but no evidence of symptomatic ischemia or infarction before the development of lethal ventricular arrhythmias, and the trigger for ventricular tachycardia (VT)/ventricular fibrillation (VF) remains unclear. We sought to identify the role of spontaneous ischemia and temporal hemodynamic factors preceding SCD using continuous telemetry of left ventricular (LV) pressure and the ECG for periods up to 5 mo in swine (n = 37) with hibernating myocardium who experience spontaneous VT/VF in the absence of heart failure or infarction. Hemodynamics and ST deviation at the time of VT/VF were compared with survivors with hibernating myocardium as well as sham controls. All episodes of VT/VF occurred during sympathetic activation and were initiated by single premature ventricular contractions, and the VT degenerated into VF in ∼ 30 s. ECG evidence of ischemia was infrequent and no different from those that survived. Baseline hemodynamics were no different among groups, but LV end-diastolic pressure during sympathetic activation was higher at the time of SCD (37 ± 4 vs. 26 ± 4 mmHg, P < 0.05) and the ECG demonstrated QT shortening (155 ± 4 vs. 173 ± 5 ms, P < 0.05). The week before SCD, both parameters were no different from survivors. These data indicate that there are no differences in the degree of sympathetic activation or hemodynamic stress when VT/VF develops in swine with hibernating myocardium. The transiently elevated LV end-diastolic pressure and QT shortening preceding VT/VF raises the possibility that electrocardiographically silent subendocardial ischemia and/or mechanoelectrical feedback serve as a trigger for the development of SCD in chronic ischemic heart disease.

The Effects of Renal Denervation on Renal Hemodynamics and Renal Vasculature in a Porcine Model

PubMed Central

Verloop, Willemien L.; Hubens, Lisette E. G.; Spiering, Wilko; Doevendans, Pieter A.; Goldschmeding, Roel; Bleys, Ronald L. A. W.; Voskuil, Michiel

2015-01-01

Rationale Recently, the efficacy of renal denervation (RDN) has been debated. It is discussed whether RDN is able to adequately target the renal nerves. Objective We aimed to investigate how effective RDN was by means of functional hemodynamic measurements and nerve damage on histology. Methods and Results We performed hemodynamic measurements in both renal arteries of healthy pigs using a Doppler flow and pressure wire. Subsequently unilateral denervation was performed, followed by repeated bilateral hemodynamic measurements. Pigs were terminated directly after RDN or were followed for 3 weeks or 3 months after the procedure. After termination, both treated and control arteries were prepared for histology to evaluate vascular damage and nerve damage. Directly after RDN, resting renal blood flow tended to increase by 29±67% (P = 0.01). In contrast, renal resistance reserve increased from 1.74 (1.28) to 1.88 (1.17) (P = 0.02) during follow-up. Vascular histopathology showed that most nerves around the treated arteries were located outside the lesion areas (8±7 out of 55±25 (14%) nerves per pig were observed within a lesion area). Subsequently, a correlation was noted between a more impaired adventitia and a reduction in renal resistance reserve (β: -0.33; P = 0.05) at three weeks of follow-up. Conclusion Only a small minority of renal nerves was targeted after RDN. Furthermore, more severe adventitial damage was related to a reduction in renal resistance in the treated arteries at follow-up. These hemodynamic and histological observations may indicate that RDN did not sufficiently target the renal nerves. Potentially, this may explain the significant spread in the response after RDN. PMID:26587981

Effects of Direct Renin Blockade on Renal & Systemic Hemodynamics and on RAAS Activity, in Weight Excess and Hypertension: A Randomized Clinical Trial.

PubMed

Kwakernaak, A J; Roksnoer, L C; Lambers Heerspink, H J; van den Berg-Garrelds, I; Lochorn, G A; van Embden Andres, J H; Klijn, M A; Kobori, H; Danser, A H J; Laverman, G D; Navis, G J

2017-01-01

The combination of weight excess and hypertension significantly contributes to cardiovascular risk and progressive kidney damage. An unfavorable renal hemodynamic profile is thought to contribute to this increased risk and may be ameliorated by direct renin inhibition (DRI). The aim of this trial was to assess the effect of DRI on renal and systemic hemodynamics and on RAAS activity, in men with weight excess and hypertension. A randomized, double-blind, cross-over clinical trial to determine the effect of DRI (aliskiren 300 mg/day), with angiotensin converting enzyme inhibition (ACEi; ramipril 10 mg/day) as a positive control, on renal and systemic hemodynamics, and on RAAS activity (n = 15). Mean (SEM) Glomerular filtration rate (101 (5) mL/min/1.73m2) remained unaffected by DRI or ACEi. Effective renal plasma flow (ERPF; 301 (14) mL/min/1.73m2) was increased in response to DRI (320 (14) mL/min/1.73m2, P = 0.012) and ACEi (317 (15) mL/min/1.73m2, P = 0.045). Filtration fraction (FF; 34 (0.8)%) was reduced by DRI only (32 (0.7)%, P = 0.044). Mean arterial pressure (109 (2) mmHg) was reduced by DRI (101 (2) mmHg, P = 0.008) and ACEi (103 (3) mmHg, P = 0.037). RAAS activity was reduced by DRI and ACEi. Albuminuria (20 [9-42] mg/d) was reduced by DRI only (12 [5-28] mg/d, P = 0.030). In men with weight excess and hypertension, DRI and ACEi improved renal and systemic hemodynamics. Both DRI and ACEi reduced RAAS activity. Thus, DRI provides effective treatment in weight excess and hypertension. Dutch trial register, registration number: 2532 www.trialregister.nl.

The response of the microcirculation to mechanical support of the heart in critical illness.

PubMed

Akin, Sakir; Kara, Atila; den Uil, Corstiaan A; Ince, Can

2016-12-01

Critical illness associated with cardiac pump failure results in reduced tissue perfusion in all organs and occurs in various conditions such as sepsis, cardiogenic shock, and heart failure. Mechanical circulatory support (MCS) devices can be used to maintain organ perfusion in patients with cardiogenic shock and decompensated chronic heart failure. However, correction of global hemodynamic parameters by MCS does not always cause a parallel improvement in microcirculatory perfusion and oxygenation of the organ systems, a condition referred to as a loss of hemodynamic coherence between macro- and microcirculation (MC). In this paper, we review the literature describing hemodynamic coherence or loss occurring during MCS of the heart. By using Embase, Medline Cochrane, Web of Science, and Google Scholar, we analyzed the literature on the response of MC and macrocirculation to MCS of the heart in critical illness. The characteristics of patients, MCS devices, and micro- and macrocirculatory parameters were very heterogenic. Short-term MCS studies (78%) described the effects of intra-aortic balloon pumps (IABPs) on the MC and macrocirculation. Improvement in MC, observed by handheld microscopy (orthogonal polarization spectral (OPS), sidestream dark-field (SDF), and Cytocam IDF imaging) in line with restored macrocirculation was found in 44% and 40% of the studies of short- and long-term MCS, respectively. In only 6 of 14 studies, hemodynamic coherence was described. It is concluded that more studies using direct visualization of the MC in short- and long-term MCS by handheld microscopy are needed, preferably randomized controlled studies, to identify the presence and clinical significance of hemodynamic coherence. It is anticipated that these further studies can enable to better identify patients who will benefit from treatment by mechanical heart support to ensure adequate organ perfusion. Copyright © 2016 Elsevier Ltd. All rights reserved.

Loss of the LIM-only protein Fhl2 impairs inflammatory reaction and scar formation after cardiac ischemia leading to better hemodynamic performance.

PubMed

Goltz, Diane; Hittetiya, Kanishka; Gevensleben, Heidrun; Kirfel, Jutta; Diehl, Linda; Meyer, Rainer; Büttner, Reinhard

2016-04-15

The pathogenesis of myocardial ischemia-reperfusion injury (MI/R) involves an inflammatory response. Since the four-and-a-half LIM domain-containing protein 2 (Fhl2) has been observed to modulate immune cell migration, we aimed to study the consequences of Fhl2(-/-) under MI/R with respect to immune reaction, scar formation, and hemodynamic performance. In a closed chest model of 1h MI/R, immune cell invasion of phagocytic monocytes was characterized by flow cytometry and immunohistochemistry. In addition, infarct size was assessed by triphenyltetrazolium chloride/Masson trichrome staining 24h/21days after reperfusion and a set of hemodynamic parameters was recorded by catheterisation in Fhl2(-/-) mice and controls. While flow cytometry did not reveal differences in myocardial CD45(high) immune cell infiltrate, histological analysis showed that infiltrating immune cells in Fhl2(-/-) animals were preferentially located in the perivascular area, whereas in wild type, immune cells were well dispersed within the area at risk. After 24h and 21days of reperfusion, infarct size was significantly reduced in Fhl2(-/-) compared to WT animals. In addition, hemodynamic performance was better in Fhl2(-/-) mice, compared to WT mice up to day 21 of reperfusion. The loss of Fhl2 leads to an altered immune response to myocardial ischemia, which results in smaller infarcts and better hemodynamic performance up to 21days after myocardial ischemia reperfusion. Immune cell invasion plays a pivotal role in the context of MI/R. Fhl2 significantly influences immune cell function and immune cell interaction with injured cardiac tissue leading to altered scar composition. Copyright © 2016 Elsevier Inc. All rights reserved.

Review article: closed-loop systems in anesthesia: is there a potential for closed-loop fluid management and hemodynamic optimization?

PubMed

Rinehart, Joseph; Liu, Ngai; Alexander, Brenton; Cannesson, Maxime

2012-01-01

Closed-loop (automated) controllers are encountered in all aspects of modern life in applications ranging from air-conditioning to spaceflight. Although these systems are virtually ubiquitous, they are infrequently used in anesthesiology because of the complexity of physiologic systems and the difficulty in obtaining reliable and valid feedback data from the patient. Despite these challenges, closed-loop systems are being increasingly studied and improved for medical use. Two recent developments have made fluid administration a candidate for closed-loop control. First, the further description and development of dynamic predictors of fluid responsiveness provides a strong parameter for use as a control variable to guide fluid administration. Second, rapid advances in noninvasive monitoring of cardiac output and other hemodynamic variables make goal-directed therapy applicable for a wide range of patients in a variety of clinical care settings. In this article, we review the history of closed-loop controllers in clinical care, discuss the current understanding and limitations of the dynamic predictors of fluid responsiveness, and examine how these variables might be incorporated into a closed-loop fluid administration system.

Lack of correlation between preoperative and intraoperative liver hemodynamics: a descriptive analysis.

PubMed

Sánchez-Cabús, Santiago; Abraldes, Juan G; Taurá, Pilar; Calatayud, David; Fondevila, Constantino; Fuster, José; Ferrer, Joana; García-Pagán, Juan Carlos; García-Valdecasas, Juan Carlos

2014-01-15

Adult living-donor liver transplantation recipients undergo important hemodynamic changes during the procedure, which in turn have proven to be of the upmost importance when dealing with small grafts, to avoid the so-called "small-for-size" syndrome. Back in 2003, we started a hemodynamic monitoring protocol in adult living-donor liver transplantation recipients, which evaluated the hemodynamic status of the patient 24 hr before, during, and 3 days after transplantation. We analyzed the correlation between the same hemodynamic variables measured in the hemodynamic laboratory and those taken in the operating room. With the exception of cardiac index and indexed systemic vascular resistance, all the other hepatic and systemic hemodynamic parameters measured before and during the intervention, as well as during and after the intervention, showed a lack of correlation. The observed lack of correlation may happen due to many factors, such as the influence of vasoactive and anesthetic drugs, total muscular relaxation, or the presence of an open abdomen. As a result, a direct comparison between hemodynamic values should only be done when measured in the same conditions.

Cerebral arterial bolus arrival time is prolonged in multiple sclerosis and associated with disability

PubMed Central

Paling, David; Thade Petersen, Esben; Tozer, Daniel J; Altmann, Daniel R; Wheeler-Kingshott, Claudia AM; Kapoor, Raju; Miller, David H; Golay, Xavier

2014-01-01

Alterations in the overall cerebral hemodynamics have been reported in multiple sclerosis (MS); however, their cause and significance is unknown. While potential venous causes have been examined, arterial causes have not. In this study, a multiple delay time arterial spin labeling magnetic resonance imaging sequence at 3T was used to quantify the arterial hemodynamic parameter bolus arrival time (BAT) and cerebral blood flow (CBF) in normal-appearing white matter (NAWM) and deep gray matter in 33 controls and 35 patients with relapsing–remitting MS. Bolus arrival time was prolonged in MS in NAWM (1.0±0.2 versus 0.9±0.2 seconds, P=0.031) and deep gray matter (0.90±0.18 versus 0.80±0.14 seconds, P=0.001) and CBF was increased in NAWM (14±4 versus 10±2 mL/100 g/min, P=0.001). Prolonged BAT in NAWM (P=0.042) and deep gray matter (P=0.01) were associated with higher expanded disability status score. This study demonstrates alteration in cerebral arterial hemodynamics in MS. One possible cause may be widespread inflammation. Bolus arrival time was longer in patients with greater disability independent of atrophy and T2 lesion load, suggesting alterations in cerebral arterial hemodynamics may be a marker of clinically relevant pathology. PMID:24045400

Advanced hemodynamic monitoring in intensive care medicine : A German web-based survey study.

PubMed

Saugel, B; Reese, P C; Wagner, J Y; Buerke, M; Huber, W; Kluge, S; Prondzinsky, R

2018-04-01

Advanced hemodynamic monitoring is recommended in patients with complex circulatory shock. To evaluate the current attitudes and beliefs among German intensivists, regarding advanced hemodynamic monitoring, the actual hemodynamic management in clinical practice, and the barriers to using it. Web-based survey among members of the German Society of Medical Intensive Care and Emergency Medicine. Of 284 respondents, 249 (87%) agreed that further hemodynamic assessment is needed to determine the type of circulatory shock if no clear clinical diagnosis can be made. In all, 281 (99%) agreed that echocardiography is helpful for this purpose (transpulmonary thermodilution: 225 [79%]; pulmonary artery catheterization: 126 [45%]). More than 70% of respondents agreed that blood flow variables (cardiac output, stroke volume) should be measured in patients with hemodynamic instability. The parameters most respondents agreed should be assessed in a patient with hemodynamic instability were mean arterial pressure, cardiac output, and serum lactate. Echocardiography is available in 99% of ICUs (transpulmonary thermodilution: 91%; pulmonary artery catheter: 63%). The respondents stated that, in clinical practice, invasive arterial pressure measurements and serum lactate measurements are performed in more than 90% of patients with hemodynamic instability (cardiac output monitoring in about 50%; transpulmonary thermodilution in about 40%). The respondents did not feel strong barriers to the use of advanced hemodynamic monitoring in clinical practice. This survey study shows that German intensivists deem advanced hemodynamic assessment necessary for the differential diagnosis of circulatory shock and to guide therapy with fluids, vasopressors, and inotropes in ICU patients.

Effect of Curcuma longa and Ocimum sanctum on myocardial apoptosis in experimentally induced myocardial ischemic-reperfusion injury

PubMed Central

Mohanty, Ipseeta; Arya, Dharamvir Singh; Gupta, Suresh Kumar

2006-01-01

Background In the present investigation, the effect of Curcuma longa (Cl) and Ocimum sanctum (Os) on myocardial apoptosis and cardiac function was studied in an ischemia and reperfusion (I-R) model of myocardial injury. Methods Wistar albino rats were divided into four groups and orally fed saline once daily (sham, control IR) or Cl (100 mg/kg; Cl-IR) or Os (75 mg/kg; Os-IR) respectively for 1 month. On the 31st day, in the rats of the control IR, Cl-IR and Os-IR groups LAD occlusion was undertaken for 45 min, and reperfusion was allowed for 1 h. The hemodynamic parameters{mean arterial pressure (MAP), heart rate (HR), left ventricular end-diastolic pressure (LVEDP), left ventricular peak positive (+) LVdP/dt (rate of pressure development) and negative (-) LVdP/dt (rate of pressure decline)} were monitored at pre-set points throughout the experimental duration and subsequently, the animals were sacrificed for immunohistopathological (Bax, Bcl-2 protein expression & TUNEL positivity) and histopathological studies. Results Chronic treatment with Cl significantly reduced TUNEL positivity (p < 0.05), Bax protein (p < 0.001) and upregulated Bcl-2 (p < 0.001) expression in comparison to control IR group. In addition, Cl demonstrated mitigating effects on several myocardial injury induced hemodynamic {(+)LVdP/dt, (-) LVdP/dt & LVEDP} and histopathological perturbations. Chronic Os treatment resulted in modest modulation of the hemodynamic alterations (MAP, LVEDP) but failed to demonstrate any significant antiapoptotic effects and prevent the histopathological alterations as compared to control IR group. Conclusion In the present study, significant cardioprotection and functional recovery demonstrated by Cl may be attributed to its anti-apoptotic property. In contrast to Os, Cl may attenuate cell death due to apoptosis and prevent the impairment of cardiac performance. PMID:16504000

Resting-state hemodynamics are spatiotemporally coupled to synchronized and symmetric neural activity in excitatory neurons.

PubMed

Ma, Ying; Shaik, Mohammed A; Kozberg, Mariel G; Kim, Sharon H; Portes, Jacob P; Timerman, Dmitriy; Hillman, Elizabeth M C

2016-12-27

Brain hemodynamics serve as a proxy for neural activity in a range of noninvasive neuroimaging techniques including functional magnetic resonance imaging (fMRI). In resting-state fMRI, hemodynamic fluctuations have been found to exhibit patterns of bilateral synchrony, with correlated regions inferred to have functional connectivity. However, the relationship between resting-state hemodynamics and underlying neural activity has not been well established, making the neural underpinnings of functional connectivity networks unclear. In this study, neural activity and hemodynamics were recorded simultaneously over the bilateral cortex of awake and anesthetized Thy1-GCaMP mice using wide-field optical mapping. Neural activity was visualized via selective expression of the calcium-sensitive fluorophore GCaMP in layer 2/3 and 5 excitatory neurons. Characteristic patterns of resting-state hemodynamics were accompanied by more rapidly changing bilateral patterns of resting-state neural activity. Spatiotemporal hemodynamics could be modeled by convolving this neural activity with hemodynamic response functions derived through both deconvolution and gamma-variate fitting. Simultaneous imaging and electrophysiology confirmed that Thy1-GCaMP signals are well-predicted by multiunit activity. Neurovascular coupling between resting-state neural activity and hemodynamics was robust and fast in awake animals, whereas coupling in urethane-anesthetized animals was slower, and in some cases included lower-frequency (<0.04 Hz) hemodynamic fluctuations that were not well-predicted by local Thy1-GCaMP recordings. These results support that resting-state hemodynamics in the awake and anesthetized brain are coupled to underlying patterns of excitatory neural activity. The patterns of bilaterally-symmetric spontaneous neural activity revealed by wide-field Thy1-GCaMP imaging may depict the neural foundation of functional connectivity networks detected in resting-state fMRI.

Resting-state hemodynamics are spatiotemporally coupled to synchronized and symmetric neural activity in excitatory neurons

PubMed Central

Ma, Ying; Shaik, Mohammed A.; Kozberg, Mariel G.; Portes, Jacob P.; Timerman, Dmitriy

2016-01-01

Brain hemodynamics serve as a proxy for neural activity in a range of noninvasive neuroimaging techniques including functional magnetic resonance imaging (fMRI). In resting-state fMRI, hemodynamic fluctuations have been found to exhibit patterns of bilateral synchrony, with correlated regions inferred to have functional connectivity. However, the relationship between resting-state hemodynamics and underlying neural activity has not been well established, making the neural underpinnings of functional connectivity networks unclear. In this study, neural activity and hemodynamics were recorded simultaneously over the bilateral cortex of awake and anesthetized Thy1-GCaMP mice using wide-field optical mapping. Neural activity was visualized via selective expression of the calcium-sensitive fluorophore GCaMP in layer 2/3 and 5 excitatory neurons. Characteristic patterns of resting-state hemodynamics were accompanied by more rapidly changing bilateral patterns of resting-state neural activity. Spatiotemporal hemodynamics could be modeled by convolving this neural activity with hemodynamic response functions derived through both deconvolution and gamma-variate fitting. Simultaneous imaging and electrophysiology confirmed that Thy1-GCaMP signals are well-predicted by multiunit activity. Neurovascular coupling between resting-state neural activity and hemodynamics was robust and fast in awake animals, whereas coupling in urethane-anesthetized animals was slower, and in some cases included lower-frequency (<0.04 Hz) hemodynamic fluctuations that were not well-predicted by local Thy1-GCaMP recordings. These results support that resting-state hemodynamics in the awake and anesthetized brain are coupled to underlying patterns of excitatory neural activity. The patterns of bilaterally-symmetric spontaneous neural activity revealed by wide-field Thy1-GCaMP imaging may depict the neural foundation of functional connectivity networks detected in resting-state fMRI. PMID:27974609

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Chunfa, E-mail: chunfa.huang@case.edu; Department of Medicine, Case Western Reserve University; Rammelkamp Center for Research and Education, MetroHealth System Campus, Cleveland, OH 44106

The glomerular capillary wall, composed of endothelial cells, the glomerular basement membrane and the podocytes, is continually subjected to hemodynamic force arising from tractional stress due to blood pressure and shear stress due to blood flow. Exposure of glomeruli to abnormal hemodynamic force such as hyperfiltration is associated with glomerular injury and progressive renal disease, and the conversion of mechanical stimuli to chemical signals in the regulation of the process is poorly understood in podocytes. By examining DNA fragmentation, apoptotic nuclear changes and cytochrome c release, we found that shear stress induced cell apoptosis in cultured podocytes. Meanwhile, podocytes exposedmore » to shear stress also stimulated c-Src phosphorylation, phospholipase D (PLD) activation and mammalian target of rapamycin (mTOR) signaling. Using the antibodies against c-Src, PLD{sub 1}, and PLD{sub 2} to perform reciprocal co-immunoprecipitations and in vitro PLD activity assay, our data indicated that c-Src interacted with and activated PLD{sub 1} but not PLD{sub 2}. The inhibition of shear stress-induced c-Src phosphorylation by PP{sub 2} (a specific inhibitor of c-Src kinase) resulted in reduced PLD activity. Phosphatidic acid, produced by shear stress-induced PLD activation, stimulated mTOR signaling, and caused podocyte hypertrophy and apoptosis.« less

Influence of body position on hemodynamics in patients with ischemic heart disease undergoing cardiac surgery.

PubMed

Mekis, Dusan; Kamenik, Mirt

2010-05-01

The cardiovascular response to decreased or increased preload in high-risk patients with ischemic heart disease enables us to understand the physiologic response to hemorrhage and its treatment. Although numerous studies have failed to show its effectiveness, the head-down position is still widely used to treat patients with hypotension and shock. The aim of our study was to evaluate the influence of body position on hemodynamics in high-risk patients undergoing coronary artery bypass graft surgery. In 16 patients with ischemic hearth disease and poor left ventricular function undergoing coronary artery bypass graft surgery, we measured cardiac output with thermodilution, arterial pressure, central venous pressure (CVP), pulmonary artery wedge pressure (PAWP) and heart rate in three different body positions: the horizontal position, 20 degrees head-up position, 20 degrees head-down position and back in the horizontal position. The measurements were made before and after cardiac surgery. Before skin incision the change from horizontal to 20 degrees head-up position led to a nonsignificant decrease in cardiac output and a significant decrease in mean arterial pressure, CVP and PAWP. The change from 20 degrees head-up to 20 degrees head-down position led to a significant increase in cardiac output, mean arterial pressure, CVP and PAWP. After skin closure the change from horizontal to 20 degrees head-up position led to a nonsignificant decrease in cardiac output and mean arterial pressure and a significant decrease CVP and PAWP. The change from 20 degrees head-up to 20 degrees head-down position led to a nonsignificant increase in cardiac output and a significant increase in mean arterial pressure, CVP and PAWP. There were no significant changes in heart rate during the changes in position before or after surgery. The results of our study showed a hemodynamic response similar to hemorrhage after placing the patients in a 20 degrees head-up position and improving hemodynamics in the head-down position in mechanically ventilated patients undergoing coronary artery bypass graft surgery.

The subxiphoid view cannot replace the apical view for transthoracic echocardiographic assessment of hemodynamic status

PubMed Central

2013-01-01

Introduction This prospective study aimed to assess whether use of the subxiphoid acoustic window in transthoracic echocardiography (TTE) can be an accurate alternative in the absence of an apical view to assess hemodynamic parameters. Methods This prospective study took place in a teaching hospital medical ICU. Over a 4-month period, TTE was performed in patients admitted for more than 24 hours. Two operators rated the quality of parasternal, apical, and subxiphoid acoustic windows as Excellent, Good, Acceptable, Poor, or No image. In the subpopulation presenting adequate (rated as acceptable or higher) apical and subxiphoid views, we compared the left ventricular ejection fraction (LVEF), the ratio between right and left ventricular end-diastolic areas (RVEDA/LVEDA), the ratio between early and late mitral inflow on pulsed Doppler (E/A ratio), the aortic velocity time integral (Ao VTI), and the ratio between early mitral inflow and displacement of the mitral annulus on tissue Doppler imaging (E/Ea ratio). Results An adequate apical view was obtained in 80%, and an adequate subxiphoid view was obtained in 63% of the 107 patients included. Only 5% of patients presented an adequate subxiphoid view without an adequate apical view. In the subpopulation of patients with adequate apical and subxiphoid windows (n = 65), LVEF, E/A, and RVEDA/LVEDA were comparable on both views, and were strongly correlated (r > 0.80) with acceptable biases and precision. However, the Ao VTI and the E/Ea ratio were lower on the subxiphoid view than on the apical view (18 ± 5 versus 16 ± 5 cm and 9.6 ± 4.6 versus 7.6 ± 4 cm, respectively, P = 0.001 for both). Conclusions An adequate TTE subxiphoid window was obtained in fewer than two thirds of ICU patients. In addition to the classic indication for the subxiphoid window to study the vena cava and pericardium, this view can be used to study right and left ventricular morphology and function, but does not provide accurate hemodynamic Doppler information. ICU echocardiographers should therefore record both apical and subxiphoid views to assess comprehensively the cardiac function and hemodynamic status. PMID:24004960

Does lung ischemia and reperfusion have an impact on coronary flow? A quantitative coronary blood-flow analysis with inflammatory cytokine profile†

PubMed Central

Karapanos, Nikolaos Tsirikos; Wettstein, Peter J.; Li, Zhuo; Huebner, Marianne; Park, Soon J.; Deschamps, Claude; Cassivi, Stephen D.

2012-01-01

OBJECTIVE Ischemia-reperfusion (IR) injury remains a major cause of early morbidity and mortality after lung transplantation with poorly documented extrapulmonary repercussions. To determine the hemodynamic effect due to lung IR injury, we performed a quantitative coronary blood-flow analysis in a swine model of in situ lung ischemia and reperfusion. METHODS In 14 healthy pigs, blood flow was measured in the ascending aorta, left anterior descending (LAD), circumflex (Cx), right coronary artery (RCA), right common carotid artery (RCCA), and left internal mammary artery (LIMA), along with left-and right-ventricular pressures (LVP and RVP), aortic pressure (AoP), and pulmonary artery pressure (PAP). Cardiac Troponin (cTn), interleukin 6 and 10 (IL-6 and IL-10), and tumor necrosis factor A (TNF-A) were measured in coronary sinus blood samples. The experimental (IR) group (n = 10) underwent 60 min of lung ischemia followed by 60 min of reperfusion by clamping and releasing the left pulmonary hilum. Simultaneous measurements of all parameters were made at baseline and during IR. The control group (n = 4) had similar measurements without lung IR. RESULTS In the IR group, total coronary flow (TCF = LAD + Cx + RCA blood-flow) decreased precipitously and significantly from baseline (113 ± 41 ml min”1) during IR (p < 0.05), with the lowest value observed at 60 min of reperfusion (-37.1%, p < 0.003). Baseline cTn (0.08 ± 0.02 ng ml−1) increased during IR and peaked at 45 min of reperfusion (+138%, p < 0.001). Baseline IL-6 (9.2 ± 2.17 pg ml−1) increased during IR and peaked at 60 min of reperfusion (+228%, p < 0.0001). Significant LVP drop at 5 min of ischemia ( p < 0.05) was followed by a slow return to baseline at 45 min of ischemia. A second LVP drop occurred at reperfusion ( p < 0.05) and persisted. Conversely, RVP increased throughout ischemia (p < 0.05) and returned toward baseline during reperfusion. Coronary blood flow and hemodynamic profile remained unchanged in the control group. IL-10 and TNF-A remained below the measurable range for both the groups. CONCLUSIONS In situ lung IR has a marked negative impact on coronary blood flow, hemodynamics, and inflammatory profile. In addition, to the best of our knowledge, this is the first study where coronary blood flow is directly measured during lung IR, revealing the associated increased cardiac risk. PMID:21900017

[Aspects of perioperative care in patients with diabetes].

PubMed

Pestel, G; Closhen, D; Zimmermann, A; Werner, C; Weber, M M

2013-01-01

Diabetes is a common disease in Germany. Due to diabetes-associated end-organ disease, such as large and small vessel disease and neuropathy, diabetic patients require more intense anesthesia care during the perioperative phase. An in-depth and comprehensive medical history focusing on hemodynamic alterations, gastroparesis, neuropathy and stiff joint syndrome is a cornerstone of perioperative care and may affect outcome of diabetes patients more than specific anesthetic medications or the anesthetic procedure. Intraoperative anesthetic care needs to focus on preservation of hemodynamic stability, perioperative infection control and maintenance of glucose homeostasis. Whereas some years ago strict glucose control by aggressive insulin therapy was adamantly advocated, the results of recent studies have put the risk of such therapeutic algorithms into perspective. Therefore, optimized perioperative care of diabetic patients consists of setting a predefined targeted blood glucose level, evidence-based therapeutic approaches to reach that goal and finally adequate and continuous monitoring and amendment of the therapeutic approach if required.

[Abdominal trauma].

PubMed

Sido, B; Grenacher, L; Friess, H; Büchler, M W

2005-09-01

Blunt abdominal trauma is much more frequent than penetrating abdominal trauma in Europe. As a consequence of improved quality of computed tomography, even complex liver injuries are increasingly being treated conservatively. However, missed hollow viscus injuries still remain a problem, as they considerably increase mortality in multiply injured patients. Laparoscopy decreases the rate of unnecessary laparotomies in perforating abdominal trauma and helps to diagnose injuries of solid organs and the diaphragm. However, the sensitivity in detecting hollow viscus injuries is low and the role of laparoscopy in blunt abdominal injury has not been defined. If intra-abdominal bleeding is difficult to control in hemodynamically unstable patients, damage control surgery with packing of the liver, total splenectomy, and provisional closure of hollow viscus injuries is of importance. Definitive surgical treatment follows hemodynamic stabilization and restoration of hemostasis. Injuries of the duodenum and pancreas after blunt abdominal trauma are often associated with other intra-abdominal injuries and the treatment depends on their location and severity.

Hemodynamic properties and arterial structure in male rat offspring with fetal hypothyroidism.

PubMed

Ghanbari, Mahboubeh; Bagheripuor, Fatemeh; Piryaei, Abbas; Zahediasl, Saleh; Noroozzadeh, Mahsa; Ghasemi, Asghar

2016-10-01

Thyroid hormones (THs) play a crucial role in the development of different systems during fetal life; fetal hypothyroidism (FH) is associated with reduced cardiac function and dimensions in neonates. The aim of this study is to determine whether TH deficiency during fetal life is associated with arterial structural and hemodynamic changes during adulthood. Hypothyroidism was induced by adding 0.025% 6-propyl-2-thiouracil in drinking water throughout pregnancy, while controls consumed only tap water. Hemodynamic parameters, cross-sectional area, intima-media thickness (IMT), and density of nuclei of smooth muscle cells and endothelial cells (ECs) in the aorta and mesenteric arteries were measured. Compared to controls, in the FH group, baseline systolic blood pressure (105.7 ± 3.1 vs. 87.9 ± 3.3 mm Hg, p < 0.01), diastolic blood pressure (64.4 ± 1.7 vs. 53.2 ± 2.1 mm Hg, p < 0.05), and mean arterial pressure (80.9 ± 2.1 vs. 67.1 ± 2.1 mm Hg, p < 0.01) were significantly lower. In addition, in the FH group, intensity and latency of response to phenylephrine were significantly lower and longer, respectively, as were the IMT and density of ECs in the aorta and superior mesenteric arteries. In conclusion, this study showed that TH deficiency during fetal life can have long-lasting functional and histological effects, which can compromise cardiovascular function during adulthood.

Computational fluid dynamics (CFD) using porous media modeling predicts recurrence after coiling of cerebral aneurysms.

PubMed

Umeda, Yasuyuki; Ishida, Fujimaro; Tsuji, Masanori; Furukawa, Kazuhiro; Shiba, Masato; Yasuda, Ryuta; Toma, Naoki; Sakaida, Hiroshi; Suzuki, Hidenori

2017-01-01

This study aimed to predict recurrence after coil embolization of unruptured cerebral aneurysms with computational fluid dynamics (CFD) using porous media modeling (porous media CFD). A total of 37 unruptured cerebral aneurysms treated with coiling were analyzed using follow-up angiograms, simulated CFD prior to coiling (control CFD), and porous media CFD. Coiled aneurysms were classified into stable or recurrence groups according to follow-up angiogram findings. Morphological parameters, coil packing density, and hemodynamic variables were evaluated for their correlations with aneurysmal recurrence. We also calculated residual flow volumes (RFVs), a novel hemodynamic parameter used to quantify the residual aneurysm volume after simulated coiling, which has a mean fluid domain > 1.0 cm/s. Follow-up angiograms showed 24 aneurysms in the stable group and 13 in the recurrence group. Mann-Whitney U test demonstrated that maximum size, dome volume, neck width, neck area, and coil packing density were significantly different between the two groups (P < 0.05). Among the hemodynamic parameters, aneurysms in the recurrence group had significantly larger inflow and outflow areas in the control CFD and larger RFVs in the porous media CFD. Multivariate logistic regression analyses demonstrated that RFV was the only independently significant factor (odds ratio, 1.06; 95% confidence interval, 1.01-1.11; P = 0.016). The study findings suggest that RFV collected under porous media modeling predicts the recurrence of coiled aneurysms.

Value of Impedance Cardiography during 6‐Minute Walk Test in Pulmonary Hypertension

PubMed Central

Alkukhun, Laith; Arelli, Vineesha; Ramos, José; Newman, Jennie; McCarthy, Kevin; Pichurko, Bohdan; Minai, Omar A.; Dweik, Raed A.

2013-01-01

Abstract Background Methods that predict prognosis and response to therapy in pulmonary hypertension (PH) are lacking. We tested whether the noninvasive estimation of hemodynamic parameters during 6‐minute walk test (6MWT) in PH patients provides information that can improve the value of the test. Methods We estimated hemodynamic parameters during the 6MWT using a portable, signal‐morphology‐based, impedance cardiograph (PhysioFlow Enduro) with real‐time wireless monitoring via a bluetooth USB adapter. Results We recruited 48 subjects in the study (30 with PH and 18 healthy controls). PH patients had significantly lower maximum stroke volume (SV) and CI and slower cardiac output (CO) acceleration and decelerations slopes during the test when compared with healthy controls. In PH patients, CI change was associated with total distance walked (R = 0.62; P < 0.001) and percentage of predicted (R = 0.4, P = 0.03), HR recovery at 1 minute (0.57, P < 0.001), 2 minutes (0.65, P < 0.001), and 3 minutes (0.66, P < 0.001). Interestingly, in PH patients CO change during the test was predominantly related to an increase in SV instead of HR. Conclusions Estimation of hemodynamic parameters such as cardiac index during 6‐minute walk test is feasible and may provide useful information in patients with PH. Clin Trans Sci 2013; Volume #: 1–7 PMID:24330692

Paraplegia after myocardial revascularization. Case report.

PubMed

Nigro Neto, Caetano; Iza, Milton Patricio Chango; Tardelli, Maria Angela

2010-01-01

Developments in anesthesiology have improved safety indices. Several techniques and agents are used to control the hemodynamic response and minimize adverse effects triggered by surgical stimuli in patients undergoing cardiac procedures. This is a 70 years old male patient, 1.74 m, 75 kg, ASA III, and NYHA II. The patient had controlled dyslipedemia, type II diabetes mellitus, and hypertension; history of smoking, peripheral vascular disease, and myocardial infarction 20 years ago. The patient underwent revascularization with the left internal mammary artery and saphenous grafts with extracorporeal circulation with intermittent clamping of the aorta. During the first 24 hours in the ICU, the patient developed hemodynamic instability, sudden hypotension, and atrial fibrillation. Twenty-six hours after the end of the surgery, the patient was awake, hemodynamically stable, and with good respiratory dynamics, being extubated. The patient was talkative and oriented, but immobile and negative reflexes in the lower limbs. Neurological evaluation showed: cranial nerves without changes, no complaints of pain below the hips, preserved superficial and deep sensitivity, adequate distal perfusion without edema, and flaccid paraplegia below T8. The echocardiogram did not show any changes. CT scan of the lumbosacral spine was negative for compressive mass in the epidural space or adjacent to it. Anterior spinal artery syndrome should be considered in procedures with manipulation of the aorta. Prevention, especially in patients at risk, is necessary. Computed tomography, for the differential diagnosis, and MRI, to localize the lesion, are important.

Computational Fluid Dynamics of Developing Avian Outflow Tract Heart Valves

PubMed Central

Bharadwaj, Koonal N.; Spitz, Cassie; Shekhar, Akshay; Yalcin, Huseyin C.; Butcher, Jonathan T.

2012-01-01

Hemodynamic forces play an important role in sculpting the embryonic heart and its valves. Alteration of blood flow patterns through the hearts of embryonic animal models lead to malformations that resemble some clinical congenital heart defects, but the precise mechanisms are poorly understood. Quantitative understanding of the local fluid forces acting in the heart has been elusive because of the extremely small and rapidly changing anatomy. In this study, we combine multiple imaging modalities with computational simulation to rigorously quantify the hemodynamic environment within the developing outflow tract (OFT) and its eventual aortic and pulmonary valves. In vivo Doppler ultrasound generated velocity profiles were applied to Micro-Computed Tomography generated 3D OFT lumen geometries from Hamburger-Hamilton (HH) stage 16 to 30 chick embryos. Computational fluid dynamics simulation initial conditions were iterated until local flow profiles converged with in vivo Doppler flow measurements. Results suggested that flow in the early tubular OFT (HH16 and HH23) was best approximated by Poiseuille flow, while later embryonic OFT septation (HH27, HH30) was mimicked by plug flow conditions. Peak wall shear stress (WSS) values increased from 18.16 dynes/cm2 at HH16 to 671.24 dynes/cm2 at HH30. Spatiotemporally averaged WSS values also showed a monotonic increase from 3.03 dynes/cm2 at HH16 to 136.50 dynes/cm2 at HH30. Simulated velocity streamlines in the early heart suggest a lack of mixing, which differed from classical ink injections. Changes in local flow patterns preceded and correlated with key morphogenetic events such as OFT septation and valve formation. This novel method to quantify local dynamic hemodynamics parameters affords insight into sculpting role of blood flow in the embryonic heart and provides a quantitative baseline dataset for future research. PMID:22535311

Aberrant Processing of Deviant Stimuli in Schizophrenia Revealed by Fusion of FMRI and EEG Data

PubMed Central

Calhoun, VD; Wu, L; Kiehl, KA; Eichele, T; Pearlson, GD

2010-01-01

Background Aberrant electrophysiological and hemodynamic processing of auditory oddball stimuli is among the most robustly documented findings in patients with schizophrenia. However, no study to date has directly examined linked patterns of electrical and hemodynamic differences in patients and controls. Methods In a recent paper we demonstrated a data-driven approach, joint independent component analysis (jICA) to fuse together functional magnetic resonance imaging (fMRI) and event-related potential (ERP) data and elucidated the chronometry of auditory oddball target detection in healthy control subjects. In this paper we extend our fusion method to identify specific differences in the neuronal chronometry of target detection for chronic schizophrenia patients compared to healthy controls. Results We found one linked source, consistent with the N2 response, known to be related to cognitive processing of deviant stimuli, spatially localized to bilateral fronto-temporal regions. This source showed significant between-group differences both in amplitude response and in the fMRI/ERP distribution pattern. These findings are consistent with previous work showing N2 amplitude and latency abnormalities in schizophrenia, and provide new information about the linkage between the two. Conclusions In summary, we use a novel approach to isolate and identify a linked fMRI/ERP component which shows marked differences in chronic schizophrenia patients. We also demonstrate that jointly using both fMRI and ERP measures provides a fully picture of the underlying hemodynamic and electrical changes which are present in patients. Our approach also has broad applicability to other diseases such as autism, Alzheimer’s disease, or bipolar disorder. PMID:21331320

Impaired Central Pulsatile Hemodynamics in Children and Adolescents With Marfan Syndrome.

PubMed

Grillo, Andrea; Salvi, Paolo; Marelli, Susan; Gao, Lan; Salvi, Lucia; Faini, Andrea; Trifirò, Giuliana; Carretta, Renzo; Pini, Alessandro; Parati, Gianfranco

2017-11-07

Marfan syndrome is characterized by aortic root dilation, beginning in childhood. Data about aortic pulsatile hemodynamics and stiffness in pediatric age are currently lacking. In 51 young patients with Marfan syndrome (12.0±3.3 years), carotid tonometry was performed for the measurement of central pulse pressure, pulse pressure amplification, and aortic stiffness (carotid-femoral pulse wave velocity). Patients underwent an echocardiogram at baseline and at 1 year follow-up and a genetic evaluation. Pathogenetic fibrillin-1 mutations were classified between "dominant negative" and "haploinsufficient." The hemodynamic parameters of patients were compared with those of 80 sex, age, blood pressure, and heart-rate matched controls. Central pulse pressure was significantly higher (38.3±12.3 versus 33.6±7.8 mm Hg; P =0.009), and pulse pressure amplification was significantly reduced in Marfan than controls (17.9±15.3% versus 32.3±17.4%; P <0.0001). Pulse wave velocity was not significantly different between Marfan and controls (4.98±1.00 versus 4.75±0.67 m/s). In the Marfan group, central pulse pressure and pulse pressure amplification were independently associated with aortic diameter at the sinuses of Valsalva (respectively, β=0.371, P =0.010; β=-0.271, P =0.026). No significant difference in hemodynamic parameters was found according to fibrillin-1 genotype. Patients who increased aortic Z-scores at 1-year follow-up presented a higher central pulse pressure than the remaining (42.7±14.2 versus 32.3±5.9 mm Hg; P =0.004). Central pulse pressure and pulse pressure amplification were impaired in pediatric Marfan syndrome, and associated with aortic root diameters, whereas aortic pulse wave velocity was similar to that of a general pediatric population. An increased central pulse pressure was present among patients whose aortic dilatation worsened at 1-year follow-up. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Neural and Hemodynamic Responses Elicited by Forelimb- and Photo-stimulation in Channelrhodopsin-2 Mice: Insights into the Hemodynamic Point Spread Function

PubMed Central

Vazquez, Alberto L.; Fukuda, Mitsuhiro; Crowley, Justin C.; Kim, Seong-Gi

2014-01-01

Hemodynamic responses are commonly used to map brain activity; however, their spatial limits have remained unclear because of the lack of a well-defined and malleable spatial stimulus. To examine the properties of neural activity and hemodynamic responses, multiunit activity, local field potential, cerebral blood volume (CBV)-sensitive optical imaging, and laser Doppler flowmetry were measured from the somatosensory cortex of transgenic mice expressing Channelrhodopsin-2 in cortex Layer 5 pyramidal neurons. The magnitude and extent of neural and hemodynamic responses were modulated using different photo-stimulation parameters and compared with those induced by somatosensory stimulation. Photo-stimulation-evoked spiking activity across cortical layers was similar to forelimb stimulation, although their activity originated in different layers. Hemodynamic responses induced by forelimb- and photo-stimulation were similar in magnitude and shape, although the former were slightly larger in amplitude and wider in extent. Altogether, the neurovascular relationship differed between these 2 stimulation pathways, but photo-stimulation-evoked changes in neural and hemodynamic activities were linearly correlated. Hemodynamic point spread functions were estimated from the photo-stimulation data and its full-width at half-maximum ranged between 103 and 175 µm. Therefore, submillimeter functional structures separated by a few hundred micrometers may be resolved using hemodynamic methods, such as optical imaging and functional magnetic resonance imaging. PMID:23761666

Correlation between electrical and hemodynamic responses during visual stimulation with graded contrasts

NASA Astrophysics Data System (ADS)

Si, Juanning; Zhang, Xin; Li, Yuejun; Zhang, Yujin; Zuo, Nianming; Jiang, Tianzi

2016-09-01

Brain functional activity involves complex cellular, metabolic, and vascular chain reactions, making it difficult to comprehend. Electroencephalography (EEG) and functional near infrared spectroscopy (fNIRS) have been combined into a multimodal neuroimaging method that captures both electrophysiological and hemodynamic information to explore the spatiotemporal characteristics of brain activity. Because of the significance of visually evoked functional activity in clinical applications, numerous studies have explored the amplitude of the visual evoked potential (VEP) to clarify its relationship with the hemodynamic response. However, relatively few studies have investigated the influence of latency, which has been frequently used to diagnose visual diseases, on the hemodynamic response. Moreover, because the latency and the amplitude of VEPs have different roles in coding visual information, investigating the relationship between latency and the hemodynamic response should be helpful. In this study, checkerboard reversal tasks with graded contrasts were used to evoke visual functional activity. Both EEG and fNIRS were employed to investigate the relationship between neuronal electrophysiological activities and the hemodynamic responses. The VEP amplitudes were linearly correlated with the hemodynamic response, but the VEP latency showed a negative linear correlation with the hemodynamic response.

Less or more hemodynamic monitoring in critically ill patients.

PubMed

Jozwiak, Mathieu; Monnet, Xavier; Teboul, Jean-Louis

2018-06-07

Hemodynamic investigations are required in patients with shock to identify the type of shock, to select the most appropriate treatments and to assess the patient's response to the selected therapy. We discuss how to select the most appropriate hemodynamic monitoring techniques in patients with shock as well as the future of hemodynamic monitoring. Over the last decades, the hemodynamic monitoring techniques have evolved from intermittent toward continuous and real-time measurements and from invasive toward less-invasive approaches. In patients with shock, current guidelines recommend the echocardiography as the preferred modality for the initial hemodynamic evaluation. In patients with shock nonresponsive to initial therapy and/or in the most complex patients, it is recommended to monitor the cardiac output and to use advanced hemodynamic monitoring techniques. They also provide other useful variables that are useful for managing the most complex cases. Uncalibrated and noninvasive cardiac output monitors are not reliable enough in the intensive care setting. The use of echocardiography should be initially encouraged in patients with shock to identify the type of shock and to select the most appropriate therapy. The use of more invasive hemodynamic monitoring techniques should be discussed on an individualized basis.

Screening for pre-eclampsia in the first trimester: role of maternal hemodynamics and bioimpedance in non-obese patients.

PubMed

Gagliardi, G; Tiralongo, G M; LoPresti, D; Pisani, I; Farsetti, D; Vasapollo, B; Novelli, G P; Andreoli, A; Valensise, H

2017-11-01

To test if maternal hemodynamics and bioimpedance, assessed at the time of combined screening for PE, are able to identify in the first trimester of gestation normotensive non-obese patients at risk for pre-eclampsia (PE) and/or intrauterine growth restriction (IUGR). One hundred and fifty healthy nulliparous non-obese women (body mass index < 30 kg/m 2 ) in the first trimester of pregnancy underwent assessment by UltraSonic Cardiac Output Monitor (USCOM) to detect hemodynamic parameters, bioimpedance analysis to characterize body composition, and combined screening for PE (assessment of maternal history, biophysical and maternal biochemical markers). Patients were followed until term, noting the appearance of PE and/or IUGR. One hundred and thirty-eight patients had an uneventful pregnancy (controls), while 12 (8%) developed complications (cases). USCOM showed, in cases compared with controls, lower cardiac output (5.6 ± 0.3 vs 6.7 ± 1.1 L/min, P < 0.001), lower inotropy index (1.54 ± 0.38 vs 1.91 ± 0.32 W/m 2 , P < 0.001) and higher total vascular resistance (1279.8 ± 166.4 vs 1061.4 ± 179.5 dynes × s/cm 5 , P < 0.001). Bioimpedance analysis showed, in cases compared with controls, lower total body water (53.7 ± 3.3% vs 57.2 ± 5.6%, P = 0.037). Combined screening was positive for PE in 8% of the controls and in 50% of the cases (P < 0.001). After identification of cut-off values for USCOM and bioimpedance parameters, forward multivariate logistic regression analysis identified as independent predictors of complications in pregnancy the inotropy index (derived by USCOM), fat mass (derived from bioimpedance analysis) and combined screening. Combined screening for PE and assessment of bioimpedance and maternal hemodynamics can be used to identify early markers of impaired cardiovascular adaptation and body composition that may lead to complications in the third trimester of pregnancy. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Standardized model of porcine resuscitation using a custom-made resuscitation board results in optimal hemodynamic management.

PubMed

Wollborn, Jakob; Ruetten, Eva; Schlueter, Bjoern; Haberstroh, Joerg; Goebel, Ulrich; Schick, Martin A

2018-01-22

Standardized modeling of cardiac arrest and cardiopulmonary resuscitation (CPR) is crucial to evaluate new treatment options. Experimental porcine models are ideal, closely mimicking human-like physiology. However, anteroposterior chest diameter differs significantly, being larger in pigs and thus poses a challenge to achieve adequate perfusion pressures and consequently hemodynamics during CPR, which are commonly achieved during human resuscitation. The aim was to prove that standardized resuscitation is feasible and renders adequate hemodynamics and perfusion in pigs, using a specifically designed resuscitation board for a pneumatic chest compression device. A "porcine-fit" resuscitation board was designed for our experiments to optimally use a pneumatic compression device (LUCAS® II, Physio-Control Inc.), which is widely employed in emergency medicine and ideal in an experimental setting due to its high standardization. Asphyxial cardiac arrest was induced in 10 German hybrid landrace pigs and cardiopulmonary resuscitation was performed according to ERC/AHA 2015 guidelines with mechanical chest compressions. Hemodynamics were measured in the carotid and pulmonary artery. Furthermore, arterial blood gas was drawn to assess oxygenation and tissue perfusion. The custom-designed resuscitation board in combination with the LUCAS® device demonstrated highly sufficient performance regarding hemodynamics during CPR (mean arterial blood pressure, MAP 46 ± 1 mmHg and mean pulmonary artery pressure, mPAP of 36 ± 1 mmHg over the course of CPR). MAP returned to baseline values at 2 h after ROSC (80 ± 4 mmHg), requiring moderate doses of vasopressors. Furthermore, stroke volume and contractility were analyzed using pulse contour analysis (106 ± 3 ml and 1097 ± 22 mmHg/s during CPR). Blood gas analysis revealed CPR-typical changes, normalizing in the due course. Thermodilution parameters did not show persistent intravascular volume shift. Standardized cardiopulmonary resuscitation is feasible in a porcine model, achieving adequate hemodynamics and consecutive tissue perfusion of consistent quality. Copyright © 2018 Elsevier Inc. All rights reserved.

Periodic leg movements during sleep and cerebral hemodynamic changes detected by NIRS.

PubMed

Pizza, Fabio; Biallas, Martin; Wolf, Martin; Valko, Philipp O; Bassetti, Claudio L

2009-07-01

Periodic leg movements during sleep (PLMS) have been shown to be associated with changes in autonomic and hemispheric activities. Near infrared spectroscopy (NIRS) assesses hemodynamic changes linked to hemispheric/cortical activity. We applied NIRS to test whether cerebral hemodynamic alterations accompany PLMS. Three PLMS patients underwent nocturnal polysomnography coupled with cerebral NIRS. EEG correlates of PLMS were scored and NIRS data were analysed for the identification of correspondent hemodynamic changes. PLMS were constantly associated with cerebral hemodynamic fluctuations that showed greater amplitude when associated to changes in EEG and were present also in absence of any visually detectable arousal or A phase in the EEG. This is the first study documenting cerebral hemodynamic changes linked to PLMS. The clinical relevance of these observations remains to be determined.

Hemodynamic Parameters during Laryngoscopic Procedures in the Office and in the Operating Room.

PubMed

Tierney, William S; Chota, Rebecca L; Benninger, Michael S; Nowacki, Amy S; Bryson, Paul C

2016-09-01

Previous research has shown that office-based laryngoscopic procedures can induce hemodynamic changes, including tachycardia and severe hypertension, calling into question the safety of these procedures. However, comparison between office and operating room (OR) procedures has not been carried out. Therefore, we prospectively measured hemodynamic variables in both settings to compare hemodynamic changes between office and OR procedures. Prospective cohort study. Single academic center. Subjects undergoing office and OR laryngoscopic procedures were prospectively identified, and 92 OR and 70 office subjects were included. Heart rate and blood pressure were measured at established time points before, during, and after the procedures. Descriptive and comparative statistical analyses were conducted. Severe hemodynamic events, either tachycardia or severe hypertension (blood pressure >180 mm Hg systolic or >110 mm Hg diastolic), occurred significantly more frequently in OR than office procedures (41% vs 20%; P = .006). OR severe hemodynamic events occurred more commonly than previously reported rates in the office (41% vs 28%; P = .012). Regression analyses showed that the odds of having a severe hemodynamic event were 3.66 times higher in OR versus office procedures. Severe hemodynamic events are more likely to occur in the OR than in the office during laryngologic procedures. While larger studies will be required to establish rates of dangerous cardiovascular events in laryngoscopic procedures, hemodynamic parameters indicate that office-based procedures have a safety benefit for procedures that can be conducted in either setting. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

A Proof of Concept Study of Function-Based Statistical Analysis of fNIRS Data: Syntax Comprehension in Children with Specific Language Impairment Compared to Typically-Developing Controls.

PubMed

Fu, Guifang; Wan, Nicholas J A; Baker, Joseph M; Montgomery, James W; Evans, Julia L; Gillam, Ronald B

2016-01-01

Functional near infrared spectroscopy (fNIRS) is a neuroimaging technology that enables investigators to indirectly monitor brain activity in vivo through relative changes in the concentration of oxygenated and deoxygenated hemoglobin. One of the key features of fNIRS is its superior temporal resolution, with dense measurements over very short periods of time (100 ms increments). Unfortunately, most statistical analysis approaches in the existing literature have not fully utilized the high temporal resolution of fNIRS. For example, many analysis procedures are based on linearity assumptions that only extract partial information, thereby neglecting the overall dynamic trends in fNIRS trajectories. The main goal of this article is to assess the ability of a functional data analysis (FDA) approach for detecting significant differences in hemodynamic responses recorded by fNIRS. Children with and without SLI wore two, 3 × 5 fNIRS caps situated over the bilateral parasylvian areas as they completed a language comprehension task. FDA was used to decompose the high dimensional hemodynamic curves into the mean function and a few eigenfunctions to represent the overall trend and variation structures over time. Compared to the most popular GLM, we did not assume any parametric structure and let the data speak for itself. This analysis identified significant differences between the case and control groups in the oxygenated hemodynamic mean trends in the bilateral inferior frontal and left inferior posterior parietal brain regions. We also detected significant group differences in the deoxygenated hemodynamic mean trends in the right inferior posterior parietal cortex and left temporal parietal junction. These findings, using dramatically different approaches, experimental designs, data sets, and foci, were consistent with several other reports, confirming group differences in the importance of these two areas for syntax comprehension. The proposed FDA was consistent with the temporal characteristics of fNIRS, thus providing an alternative methodology for fNIRS analyses.

Tracheal intubation in critically ill patients: a comprehensive systematic review of randomized trials.

PubMed

Cabrini, Luca; Landoni, Giovanni; Baiardo Radaelli, Martina; Saleh, Omar; Votta, Carmine D; Fominskiy, Evgeny; Putzu, Alessandro; Snak de Souza, Cézar Daniel; Antonelli, Massimo; Bellomo, Rinaldo; Pelosi, Paolo; Zangrillo, Alberto

2018-01-20

We performed a systematic review of randomized controlled studies evaluating any drug, technique or device aimed at improving the success rate or safety of tracheal intubation in the critically ill. We searched PubMed, BioMed Central, Embase and the Cochrane Central Register of Clinical Trials and references of retrieved articles. Finally, pertinent reviews were also scanned to detect further studies until May 2017. The following inclusion criteria were considered: tracheal intubation in adult critically ill patients; randomized controlled trial; study performed in Intensive Care Unit, Emergency Department or ordinary ward; and work published in the last 20 years. Exclusion criteria were pre-hospital or operating theatre settings and simulation-based studies. Two investigators selected studies for the final analysis. Extracted data included first author, publication year, characteristics of patients and clinical settings, intervention details, comparators and relevant outcomes. The risk of bias was assessed with the Cochrane Collaboration's Risk of Bias tool. We identified 22 trials on use of a pre-procedure check-list (1 study), pre-oxygenation or apneic oxygenation (6 studies), sedatives (3 studies), neuromuscular blocking agents (1 study), patient positioning (1 study), video laryngoscopy (9 studies), and post-intubation lung recruitment (1 study). Pre-oxygenation with non-invasive ventilation (NIV) and/or high-flow nasal cannula (HFNC) showed a possible beneficial role. Post-intubation recruitment improved oxygenation , while ramped position increased the number of intubation attempts and thiopental had negative hemodynamic effects. No effect was found for use of a checklist, apneic oxygenation (on oxygenation and hemodynamics), videolaryngoscopy (on number and length of intubation attempts), sedatives and neuromuscular blockers (on hemodynamics). Finally, videolaryngoscopy was associated with severe adverse effects in multiple trials. The limited available evidence supports a beneficial role of pre-oxygenation with NIV and HFNC before intubation of critically ill patients. Recruitment maneuvers may increase post-intubation oxygenation. Ramped position increased the number of intubation attempts; thiopental had negative hemodynamic effects and videolaryngoscopy might favor adverse events.

Dexmedetomidine in the Supratentorial Craniotomy

PubMed Central

Ilhan, Osman; Koruk, Senem; Serin, Gokcen; Erkutlu, Ibrahim; Oner, Unsal

2010-01-01

Objective: In this double-blind prospective clinical study, we investigated the effects of fentanyl and dexmedetomidine as adjuvant agents in supratentorial craniotomies on the following: hemodynamic changes during perioperative and recovery periods, brain edema perioperatively, recovery times and side effects, such as hypertension, shivering, nausea and vomiting. Materials and Methods: Thirty consenting ASA physical status I–II patients undergoing intracranial tumor surgery were randomly divided in two groups. In group D (n=15), dexmedetomidine was infused as a 1 μg/kg bolus dose 10 minutes before induction of anesthesia and maintained with 0.4–0.5 μg/kg/min during the operation. In group F (n=15), animals were given fentanyl 0.02 μg/kg/min as an infusion for anesthesia maintenance. At induction, fentanyl was given as a 2 μg/kg dose in group D and as a 4 μg/kg dose in group F. Hemodynamic changes, recovery times and postoperative side effects were recorded before induction, during the perioperative period and 24 hours postoperatively. Results: In group D; MAP and HR values after intubation, after skull clamp insertion and after extubation were lower than in group F (p<0.05). In group D, cerebral relaxation scores were also significantly lower. Recovery times were found to be shorter in group D as compared to group F; the same trend was observed for the supplemental opioid requirement. During the postoperative period, there was no shivering, nausea or vomiting in group D, but in group F, 3 patients complained of shivering, and 2 patients experienced nausea and vomiting. Conclusion: In our study, we found that dexmedetomidine controlled the hemodynamic changes better than fentanyl perioperatively, after extubation and during the early postoperative period. Our results suggest that that dexmedetomidine is safer and more effective in controlling hemodynamic changes during surgical stimulation than the standard agents used in neuroanesthesia. PMID:25610125

Improvements in the Hemodynamic Stability of Combat Casualties During En Route Care

DTIC Science & Technology

2013-01-01

IMPROVEMENTS IN THE HEMODYNAMIC STABILITY OF COMBAT CASUALTIES DURING EN ROUTE CARE Amy N. Apodaca,* Jonathan J. Morrison,†‡ Mary Ann Spott,* John J...greater clinical capability is associated with an improved hemodynamic status in critical casualties. The ideal prehospital triage should endeavor to...before out of theater medical evacuation (MEDEVAC). As SI is measure of hemodynamic stability, patients with isolated severe brain injury or

Measurements of coherent hemodynamics to enrich the physiological information provided by near-infrared spectroscopy (NIRS) and functional MRI

NASA Astrophysics Data System (ADS)

Sassaroli, Angelo; Tgavalekos, Kristen; Pham, Thao; Krishnamurthy, Nishanth; Fantini, Sergio

2018-02-01

Hemodynamic-based neuroimaging techniques such as functional magnetic resonance imaging (fMRI) and near-infrared spectroscopy (NIRS) sense hemoglobin concentration in cerebral tissue. The local concentration of hemoglobin, which is differentiated into oxy- and deoxy-hemoglobin by NIRS, features spontaneous oscillations over time scales of 10-100 s in response to a number of local and systemic physiological processes. If one of such processes becomes the dominant source of cerebral hemodynamics, there is a high coherence between this process and the associated hemodynamics. In this work, we report a method to identify such conditions of coherent hemodynamics, which may be exploited to study and quantify microvasculature and microcirculation properties. We discuss how a critical value of significant coherence may depend on the specific data collection scheme (for example, the total acquisition time) and the nature of the hemodynamic data (in particular, oxy- and deoxy-hemoglobin concentrations measured with NIRS show an intrinsic level of correlation that must be taken into account). A frequency-resolved study of coherent hemodynamics is the basis for the new technique of coherent hemodynamics spectroscopy (CHS), which aims to provide measures of cerebral blood flow and cerebral autoregulation. While these concepts apply in principle to both fMRI and NIRS data, in this article we focus on NIRS data.

Does point-of-care functional echocardiography enhance cardiovascular care in the NICU?

PubMed

Sehgal, A; McNamara, P J

2008-11-01

Although the last two decades have seen major advances in the care of sick, extremely premature newborns, the approach to cardiovascular assessment and monitoring remains suboptimal owing to an overreliance on poorly predictive clinical markers such as heart rate or capillary refill time. Point-of-care functional echocardiography (PCFecho) enables real-time evaluation of cardiac performance and systemic hemodynamics to characterize acute physiology, identify the exact nature of cardiovascular compromise and guide therapeutic decisions. In this article, we will review four clinical scenarios where bedside functional cardiac imaging enabled delineation of the real clinical problem and refinement of the therapeutic care plan with direct patient benefits.

Water immersion in preeclampsia.

PubMed

Elvan-Taşpinar, Ayten; Franx, Arie; Delprat, Constance C; Bruinse, Hein W; Koomans, Hein A

2006-12-01

Preeclampsia is associated with profound vasoconstriction in most organ systems and reduced plasma volume. Because water immersion produces a marked central redistribution of blood volume and suppresses the renin-angiotensin system response and sympathetic activity, we hypothesized that water immersion might be useful in the treatment of preeclampsia. The effects of thermoneutral water immersion for 3 hours on central and peripheral hemodynamics were evaluated in 7 preeclamptic patients, 7 normal pregnant control patients, and 7 nonpregnant women. Finger plethysmography was used to determine hemodynamic measurements (cardiac output and total peripheral resistance), and forearm blood flow was measured by strain gauge plethysmography. Postischemic hyperemia was used to determine endothelium-dependent vasodilation. Analysis was by analysis of variance for repeated measurements. During water immersion cardiac output increased while diastolic blood pressure and heart rate decreased, although systolic blood pressure remained unchanged in each group. Forearm blood flow increased significantly in the normal pregnant and preeclamptic subjects. Total peripheral resistance decreased in all groups, but values in preeclamptic patients remained above those of normotensive pregnant women. Water immersion had no effect on endothelium-dependent vasodilation in the preeclamptic group, and most hemodynamic changes that were observed reversed to baseline within 2 hours of completion of the procedure. Although water immersion results in hemodynamic alterations in a manner that is theoretically therapeutic for women with preeclampsia, the effect was limited and short-lived. In addition water immersion had no effect on endothelium-dependent vasodilation in women with preeclampsia. The therapeutic potential for water immersion in preeclampsia appears to be limited.

Noninvasive photoacoustic computed tomography of mouse brain metabolism in vivo

NASA Astrophysics Data System (ADS)

Yao, Junjie; Xia, Jun; Maslov, Konstantin; Avanaki, Mohammadreza R. N.; Tsytsarev, Vassiliy; Demchenko, Alexei V.; Wang, Lihong V.

2013-03-01

To control the overall action of the body, brain consumes a large amount of energy in proportion to its volume. In humans and many other species, the brain gets most of its energy from oxygen-dependent metabolism of glucose. An abnormal metabolic rate of glucose and/or oxygen usually reflects a diseased status of brain, such as cancer or Alzheimer's disease. We have demonstrated the feasibility of imaging mouse brain metabolism using photoacoustic computed tomography (PACT), a fast, noninvasive and functional imaging modality with optical contrast and acoustic resolution. Brain responses to forepaw stimulations were imaged transdermally and transcranially. 2-NBDG, which diffuses well across the blood-brain-barrier, provided exogenous contrast for photoacoustic imaging of glucose response. Concurrently, hemoglobin provided endogenous contrast for photoacoustic imaging of hemodynamic response. Glucose and hemodynamic responses were quantitatively unmixed by using two-wavelength measurements. We found that glucose uptake and blood perfusion around the somatosensory region of the contralateral hemisphere were both increased by stimulations, indicating elevated neuron activity. The glucose response amplitude was about half that of the hemodynamic response. While the glucose response area was more homogenous and confined within the somatosensory region, the hemodynamic response area showed a clear vascular pattern and spread about twice as wide as that of the glucose response. The PACT of mouse brain metabolism was validated by high-resolution open-scalp OR-PAM and fluorescence imaging. Our results demonstrate that 2-NBDG-enhanced PACT is a promising tool for noninvasive studies of brain metabolism.

Dynamic cerebral autoregulation measured with coherent hemodynamics spectroscopy (CHS)

NASA Astrophysics Data System (ADS)

Kainerstorfer, Jana M.; Sassaroli, Angelo; Tgavalekos, Kristen T.; Fantini, Sergio

2015-03-01

Coherent Hemodynamics Spectroscopy (CHS) is a novel technique for non-invasive measurements of local microcirculation quantities such as the capillary blood transit times and dynamic autoregulation. The basis of CHS is to measure, for instance with near-infrared spectroscopy (NIRS), peripheral coherent hemodynamic changes that are induced by controlled perturbations in the systemic mean arterial pressure (MAP). In this study, the MAP perturbation was induced by the fast release of two pneumatic cuffs placed around the subject's thighs after they were kept inflated (at 200 mmHg) for two minutes. The resulting transient changes in cerebral oxy- (O) and deoxy- (D) hemoglobin concentrations measured with NIRS on the prefrontal cortex are then described by a novel hemodynamic model, from which quantifiable parameters such as the capillary blood transit time and a cutoff frequency for cerebral autoregulation are obtained. We present results on eleven healthy volunteers in a protocol involving measurements during normal breathing and during hyperventilation, which is known to cause a hypocapnia-induced increase in cerebral autoregulation. The measured capillary transit time was unaffected by hyperventilation (normal breathing: 1.1±0.1 s; hyperventilation: 1.1±0.1 s), whereas the cutoff frequency of autoregulation, which increases for higher autoregulation efficiency, was indeed found to be significantly greater during hyperventilation (normal breathing: 0.017±0.002 Hz; hyperventilation: 0.034±0.005 Hz). These results provide a validation of local cerebral autoregulation measurements with the new technique of CHS.

Slow spontaneous hemodynamic oscillations during sleep measured with near-infrared spectroscopy

NASA Astrophysics Data System (ADS)

Virtanen, Jaakko; Näsi, Tiina; Noponen, Tommi; Toppila, Jussi; Salmi, Tapani; Ilmoniemi, Risto J.

2011-07-01

Spontaneous cerebral hemodynamic oscillations below 100 mHz reflect the level of cerebral activity, modulate hemodynamic responses to tasks and stimuli, and may aid in detecting various pathologies of the brain. Near-infrared spectroscopy (NIRS) is ideally suited for both measuring spontaneous hemodynamic oscillations and monitoring sleep, but little research has been performed to combine these two applications. We analyzed 30 all-night NIRS-electroencephalography (EEG) sleep recordings to investigate spontaneous hemodynamic activity relative to sleep stages determined by polysomnography. Signal power of hemodynamic oscillations in the low-frequency (LF, 40-150 mHz) and very-low-frequency (VLF, 3-40 mHz) bands decreased in slow-wave sleep (SWS) compared to light sleep (LS) and rapid-eye-movement (REM) sleep. No statistically significant (p < 0.05) differences in oscillation power between LS and REM were observed. However, the period of VLF oscillations around 8 mHz increased in REM sleep in line with earlier studies with other modalities. These results increase our knowledge of the physiology of sleep, complement EEG data, and demonstrate the applicability of NIRS to studying spontaneous hemodynamic fluctuations during sleep.

Cyclic Alternating Pattern Is Associated with Cerebral Hemodynamic Variation: A Near-Infrared Spectroscopy Study of Sleep in Healthy Humans

PubMed Central

Toppila, Jussi; Salmi, Tapani; Ilmoniemi, Risto J.

2012-01-01

The cyclic alternating pattern (CAP), that is, cyclic variation of brain activity within non-REM sleep stages, is related to sleep instability and preservation, as well as consolidation of learning. Unlike the well-known electrical activity of CAP, its cerebral hemodynamic counterpart has not been assessed in healthy subjects so far. We recorded scalp and cortical hemodynamics with near-infrared spectroscopy on the forehead and systemic hemodynamics (heart rate and amplitude of the photoplethysmograph) with a finger pulse oximeter during 23 nights in 11 subjects. Electrical CAP activity was recorded with a polysomnogram. CAP was related to changes in scalp, cortical, and systemic hemodynamic signals that resembled the ones seen in arousal. Due to their repetitive nature, CAP sequences manifested as low- and very-low-frequency oscillations in the hemodynamic signals. The subtype A3+B showed the strongest hemodynamic changes. A transient hypoxia occurred during CAP cycles, suggesting that an increased CAP rate, especially with the subtype A3+B, which may result from diseases or fragmented sleep, might have an adverse effect on the cerebral vasculature. PMID:23071658

Cyclic alternating pattern is associated with cerebral hemodynamic variation: a near-infrared spectroscopy study of sleep in healthy humans.

PubMed

Näsi, Tiina; Virtanen, Jaakko; Toppila, Jussi; Salmi, Tapani; Ilmoniemi, Risto J

2012-01-01

The cyclic alternating pattern (CAP), that is, cyclic variation of brain activity within non-REM sleep stages, is related to sleep instability and preservation, as well as consolidation of learning. Unlike the well-known electrical activity of CAP, its cerebral hemodynamic counterpart has not been assessed in healthy subjects so far. We recorded scalp and cortical hemodynamics with near-infrared spectroscopy on the forehead and systemic hemodynamics (heart rate and amplitude of the photoplethysmograph) with a finger pulse oximeter during 23 nights in 11 subjects. Electrical CAP activity was recorded with a polysomnogram. CAP was related to changes in scalp, cortical, and systemic hemodynamic signals that resembled the ones seen in arousal. Due to their repetitive nature, CAP sequences manifested as low- and very-low-frequency oscillations in the hemodynamic signals. The subtype A3+B showed the strongest hemodynamic changes. A transient hypoxia occurred during CAP cycles, suggesting that an increased CAP rate, especially with the subtype A3+B, which may result from diseases or fragmented sleep, might have an adverse effect on the cerebral vasculature.

Use of the Kalman Filter for Aortic Pressure Waveform Noise Reduction

PubMed Central

Lu, Hsiang-Wei; Wu, Chung-Che; Aliyazicioglu, Zekeriya; Kang, James S.

2017-01-01

Clinical applications that require extraction and interpretation of physiological signals or waveforms are susceptible to corruption by noise or artifacts. Real-time hemodynamic monitoring systems are important for clinicians to assess the hemodynamic stability of surgical or intensive care patients by interpreting hemodynamic parameters generated by an analysis of aortic blood pressure (ABP) waveform measurements. Since hemodynamic parameter estimation algorithms often detect events and features from measured ABP waveforms to generate hemodynamic parameters, noise and artifacts integrated into ABP waveforms can severely distort the interpretation of hemodynamic parameters by hemodynamic algorithms. In this article, we propose the use of the Kalman filter and the 4-element Windkessel model with static parameters, arterial compliance C, peripheral resistance R, aortic impedance r, and the inertia of blood L, to represent aortic circulation for generating accurate estimations of ABP waveforms through noise and artifact reduction. Results show the Kalman filter could very effectively eliminate noise and generate a good estimation from the noisy ABP waveform based on the past state history. The power spectrum of the measured ABP waveform and the synthesized ABP waveform shows two similar harmonic frequencies. PMID:28611850

Computational modeling of cardiac hemodynamics: Current status and future outlook

NASA Astrophysics Data System (ADS)

Mittal, Rajat; Seo, Jung Hee; Vedula, Vijay; Choi, Young J.; Liu, Hang; Huang, H. Howie; Jain, Saurabh; Younes, Laurent; Abraham, Theodore; George, Richard T.

2016-01-01

The proliferation of four-dimensional imaging technologies, increasing computational speeds, improved simulation algorithms, and the widespread availability of powerful computing platforms is enabling simulations of cardiac hemodynamics with unprecedented speed and fidelity. Since cardiovascular disease is intimately linked to cardiovascular hemodynamics, accurate assessment of the patient's hemodynamic state is critical for the diagnosis and treatment of heart disease. Unfortunately, while a variety of invasive and non-invasive approaches for measuring cardiac hemodynamics are in widespread use, they still only provide an incomplete picture of the hemodynamic state of a patient. In this context, computational modeling of cardiac hemodynamics presents as a powerful non-invasive modality that can fill this information gap, and significantly impact the diagnosis as well as the treatment of cardiac disease. This article reviews the current status of this field as well as the emerging trends and challenges in cardiovascular health, computing, modeling and simulation and that are expected to play a key role in its future development. Some recent advances in modeling and simulations of cardiac flow are described by using examples from our own work as well as the research of other groups.

Percutaneous left ventricular assist device with TandemHeart for high-risk percutaneous coronary intervention: the Mayo Clinic experience.

PubMed

Alli, Oluseun O; Singh, Inder M; Holmes, David R; Pulido, Juan N; Park, Soon J; Rihal, Charanjit S

2012-11-01

In patients with poor left ventricular function and severe left main or multivessel coronary disease, coronary artery bypass grafting (CABG) surgery has been the preferred therapy. However, a number of these patients are either inoperable or poor surgical candidates due to comorbid conditions and previous cardiac surgical procedures. These patients are generally poor candidates for standard percutaneous coronary intervention (PCI) techniques. A hybrid PCI approach with hemodynamic support may be a viable strategy for these patients. We report our experience using the TandemHeart percutaneous left ventricular assist device during high-risk PCI. Retrospective cross-sectional analysis of prospectively collected data in 54 patients undergoing high-risk PCI using the TandemHeart device for support. Hemodynamic and clinical data were collected and analyzed. Baseline clinical characteristics were as follows: mean age 72 ± 1.7 years, males 78%, median ejection fraction 20%, mean serum creatinine 1.6 ± 0.3 2 mg/dL, recent myocardial infarction 52%, COPD 33%, previous CABG 50%, diabetes mellitus 41%, and hypertension 83%. The median SYNTAX score was 33, and the median Jeopardy score was 10. The predicted surgical revascularization mortality was 13% by the Society for Thoracic Surgery risk score and 33% by Euroscore. There was a significant decrease in right and left heart pressures (P < 0.05) with a concomitant increase in the cardiac output from 4.7 to 5.7 L/min (P = 0.03) during TandemHeart support. Left main and multivessel PCI was performed in 62% of patients, and rotablation was used in 48%. Procedural success rate was 97%, whereas 30-day and 6 month survival were 90% and 87%, respectively. Major vascular complications occurred in 13% of cases. None of our patients developed contrast induced nephropathy or needed dialysis. High-risk PCI with percutaneous left ventricular support using TandemHeart is a viable therapeutic strategy for a select subset of patients at very high risk with standard percutaneous revascularization techniques. Copyright © 2012 Wiley Periodicals, Inc.

Depressed left ventricular performance. Response to volume infusion in patients with sepsis and septic shock

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ognibene, F.P.; Parker, M.M.; Natanson, C.

Volume infusion, to increase preload and to enhance ventricular performance, is accepted as initial management of septic shock. Recent evidence has demonstrated depressed myocardial function in human septic shock. We analyzed left ventricular performance during volume infusion using serial data from simultaneously obtained pulmonary artery catheter hemodynamic measurements and radionuclide cineangiography. Critically ill control subjects (n = 14), patients with sepsis but without shock (n = 21), and patients with septic shock (n = 21) had prevolume infusion hemodynamic measurements determined and received statistically similar volumes of fluid resulting in similar increases in pulmonary capillary wedge pressure. There was amore » strong trend (p = 0.004) toward less of a change in left ventricular stroke work index (LVSWI) after volume infusion in patients with sepsis and septic shock compared with control subjects. The LVSWI response after volume infusion was significantly less in patients with septic shock when compared with critically ill control subjects (p less than 0.05). These data demonstrate significantly altered ventricular performance, as measured by LVSWI, in response to volume infusion in patients with septic shock.« less

Influence of voluntary control of masticatory side and rhythm on cerebral hemodynamics.

PubMed

Hasegawa, Yoko; Ono, Takahiro; Sakagami, Joe; Hori, Kazuhiro; Maeda, Yoshinobu; Hamasaki, Toshimitsu; Nokubi, Takashi

2011-02-01

The aim of this study was to investigate the influence on cerebral hemodynamics of voluntary control of masticatory side and rhythm during gum chewing. Blood flow velocity in the middle cerebral artery was measured using transcranial Doppler ultrasonography to evaluate cerebral circulation in healthy volunteers. Heart rate and masseter muscle activity were recorded simultaneously. Volunteers performed three tasks: (1) free gum chewing, (2) gum chewing in which mastication was limited to the right side, and (3) gum chewing in which mastication was limited to the right side and rhythm was set at 1.0 Hz. Changes in cerebral circulation during pre-task, on-task, and post-task periods were analyzed using random effects model, and differences in cerebral circulation and muscle activity between tasks were analyzed using the Friedman test. In all tasks, on-task cerebral circulation was greater than pre-task. Muscle activity and masticatory rhythm varied between tasks, whereas the rate of increase in cerebral circulation did not differ significantly among tasks. These results suggest that cerebral circulation is activated during gum chewing, irrespective of voluntary control of masticatory side and rhythm.

Hemodynamic and ADH responses to central blood volume shifts in cardiac-denervated humans

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Thompson, C. A.; Benjamin, B. A.; Keil, L. C.; Savin, W. M.; Gordon, E. P.; Haskell, W. L.; Schroeder, J. S.; Sandler, H.

1990-01-01

Hemodynamic responses and antidiuretic hormone (ADH) were measured during body position changes designed to induce blood volume shifts in ten cardiac transplant recipients to assess the contribution of cardiac and vascular volume receptors in the control of ADH secretion. Each subject underwent 15 min of a control period in the seated posture, then assumed a lying posture for 30 min at 6 deg head down tilt (HDT) followed by 20 min of seated recovery. Venous blood samples and cardiac dimensions (echocardiography) were taken at 0 and 15 min before HDT, 5, 15, and 30 min of HDT, and 5, 15, and 30 min of seated recovery. Blood samples were analyzed for hematocrit, plasma osmolality, plasma renin activity (PRA), and ADH. Resting plasma volume (PV) was measured by Evans blue dye and percent changes in PV during posture changes were calculated from changes in hematocrit. Heart rate (HR) and blood pressure (BP) were recorded every 2 min. Results indicate that cardiac volume receptors are not the only mechanism for the control of ADH release during acute blood volume shifts in man.

Verification of a research prototype for hemodynamic analysis of cerebral aneurysms.

PubMed

Suzuki, Takashi; Ioan Nita, Cosmin; Rapaka, Saikiran; Takao, Hiroyuki; Mihalef, Viorel; Fujimura, Soichiro; Dahmani, Chihebeddine; Sharma, Puneet; Mamori, Hiroya; Ishibashi, Toshihiro; Redel, Thomas; Yamamoto, Makoto; Murayama, Yuichi

2016-08-01

Owing to its clinical importance, there has been a growing body of research on understanding the hemodynamics of cerebral aneurysms. Traditionally, this work has been performed using general-purpose, state-of-the-art commercial solvers. This has meant requiring engineering expertise for making appropriate choices on the geometric discretization, time-step selection, choice of boundary conditions etc. Recently, a CFD research prototype has been developed (Siemens Healthcare GmbH, Prototype - not for diagnostic use) for end-to-end analysis of aneurysm hemodynamics. This prototype enables anatomical model preparation, hemodynamic computations, advanced visualizations and quantitative analysis capabilities. In this study, we investigate the accuracy of the hemodynamic solver in the prototype against a commercially available CFD solver ANSYS CFX 16.0 (ANSYS Inc., Canonsburg, PA, www.ansys.com) retrospectively on a sample of twenty patient-derived aneurysm models, and show good agreement of hemodynamic parameters of interest.

Reduced Metaboreflex Control of Blood Pressure during Exercise in Individuals with Intellectual Disability: A Possible Contributor to Exercise Intolerance

ERIC Educational Resources Information Center

Dipla, K.; Zafeiridis, A.; Papadopoulos, S.; Koskolou, M.; Geladas, N.; Vrabas, I. S.

2013-01-01

The aim was to investigate the hemodynamic responses to isometric handgrip exercise (HG) and examine the role of the muscle metaboreflex in the exercise pressor response in individuals with intellectual disability (IID) and non-disabled control subjects. Eleven males with mild-moderate intellectual disabilities and eleven non-disabled males…

Blood urea nitrogen to serum creatinine ratio is an accurate predictor of outcome in diarrhea-associated hemolytic uremic syndrome, a preliminary study.

PubMed

Keenswijk, Werner; Vanmassenhove, Jill; Raes, Ann; Dhont, Evelyn; Vande Walle, Johan

2017-03-01

Diarrhea-associated hemolytic uremic syndrome (D+HUS) is a common thrombotic microangiopathy during childhood and early identification of parameters predicting poor outcome could enable timely intervention. This study aims to establish the accuracy of BUN-to-serum creatinine ratio at admission, in addition to other parameters in predicting the clinical course and outcome. Records were searched for children between 1 January 2008 and 1 January 2015 admitted with D+HUS. A complicated course was defined as developing one or more of the following: neurological dysfunction, pancreatitis, cardiac or pulmonary involvement, hemodynamic instability, and hematologic complications while poor outcome was defined by death or development of chronic kidney disease. Thirty-four children were included from which 11 with a complicated disease course/poor outcome. Risk of a complicated course/poor outcome was strongly associated with oliguria (p = 0.000006) and hypertension (p = 0.00003) at presentation. In addition, higher serum creatinine (p = 0.000006) and sLDH (p = 0.02) with lower BUN-to-serum creatinine ratio (p = 0.000007) were significantly associated with development of complications. A BUN-to-sCreatinine ratio ≤40 at admission was a sensitive and highly specific predictor of a complicated disease course/poor outcome. A BUN-to-serum Creatinine ratio can accurately identify children with D+HUS at risk for a complicated course and poor outcome. What is Known: • Oliguria is a predictor of poor long-term outcome in D+HUS What is New: • BUN-to-serum Creatinine ratio at admission is an entirely novel and accurate predictor of poor outcome and complicated clinical outcome in D+HUS • Early detection of the high risk group in D+HUS enabling early treatment and adequate monitoring.

Computational medical imaging and hemodynamics framework for functional analysis and assessment of cardiovascular structures.

PubMed

Wong, Kelvin K L; Wang, Defeng; Ko, Jacky K L; Mazumdar, Jagannath; Le, Thu-Thao; Ghista, Dhanjoo

2017-03-21

Cardiac dysfunction constitutes common cardiovascular health issues in the society, and has been an investigation topic of strong focus by researchers in the medical imaging community. Diagnostic modalities based on echocardiography, magnetic resonance imaging, chest radiography and computed tomography are common techniques that provide cardiovascular structural information to diagnose heart defects. However, functional information of cardiovascular flow, which can in fact be used to support the diagnosis of many cardiovascular diseases with a myriad of hemodynamics performance indicators, remains unexplored to its full potential. Some of these indicators constitute important cardiac functional parameters affecting the cardiovascular abnormalities. With the advancement of computer technology that facilitates high speed computational fluid dynamics, the realization of a support diagnostic platform of hemodynamics quantification and analysis can be achieved. This article reviews the state-of-the-art medical imaging and high fidelity multi-physics computational analyses that together enable reconstruction of cardiovascular structures and hemodynamic flow patterns within them, such as of the left ventricle (LV) and carotid bifurcations. The combined medical imaging and hemodynamic analysis enables us to study the mechanisms of cardiovascular disease-causing dysfunctions, such as how (1) cardiomyopathy causes left ventricular remodeling and loss of contractility leading to heart failure, and (2) modeling of LV construction and simulation of intra-LV hemodynamics can enable us to determine the optimum procedure of surgical ventriculation to restore its contractility and health This combined medical imaging and hemodynamics framework can potentially extend medical knowledge of cardiovascular defects and associated hemodynamic behavior and their surgical restoration, by means of an integrated medical image diagnostics and hemodynamic performance analysis framework.

[Usefullness of Beta-blocker for Hemodynamic Changes Induced by Uterotonic Drug in a Patient with Hypertrophic Obstructive Cardiomyopathy Undergoing Elective Cesarean Section].

PubMed

Tsukano, Yuri; Sugita, Michiko; Ikuta, Yoshihiro; Yamamoto, Tatsuo

2015-06-01

Combined spinal-epidural anesthesia (CSEA) was given to a 27-year-old woman with hypertrophic obstructive cardiomyopathy (HOCM) for a selective cesarean section. After the injection of uterotonic drug via uterine muscle and a vein after delivery, the patient developed dyspnea, tachycardia, ST-change on elecrocardiogram and hypotension. It is important in HOCM patients to control heart rate and left ventricular contractile force. We started to infuse beta-blocker (landiolol, 10 μg x kg(-1) x min(-1)) and improved these symptoms of the patient. This case demonstrates that CSEA is safe for HOCM patients and beta-blocker is effective to improve hemodynamic changes induced by uterotonic drug in these patients.

Effect of a perioperative, cardiac output-guided hemodynamic therapy algorithm on outcomes following major gastrointestinal surgery: a randomized clinical trial and systematic review.

PubMed

Pearse, Rupert M; Harrison, David A; MacDonald, Neil; Gillies, Michael A; Blunt, Mark; Ackland, Gareth; Grocott, Michael P W; Ahern, Aoife; Griggs, Kathryn; Scott, Rachael; Hinds, Charles; Rowan, Kathryn

2014-06-04

Small trials suggest that postoperative outcomes may be improved by the use of cardiac output monitoring to guide administration of intravenous fluid and inotropic drugs as part of a hemodynamic therapy algorithm. To evaluate the clinical effectiveness of a perioperative, cardiac output-guided hemodynamic therapy algorithm. OPTIMISE was a pragmatic, multicenter, randomized, observer-blinded trial of 734 high-risk patients aged 50 years or older undergoing major gastrointestinal surgery at 17 acute care hospitals in the United Kingdom. An updated systematic review and meta-analysis were also conducted including randomized trials published from 1966 to February 2014. Patients were randomly assigned to a cardiac output-guided hemodynamic therapy algorithm for intravenous fluid and inotrope (dopexamine) infusion during and 6 hours following surgery (n=368) or to usual care (n=366). The primary outcome was a composite of predefined 30-day moderate or major complications and mortality. Secondary outcomes were morbidity on day 7; infection, critical care-free days, and all-cause mortality at 30 days; all-cause mortality at 180 days; and length of hospital stay. Baseline patient characteristics, clinical care, and volumes of intravenous fluid were similar between groups. Care was nonadherent to the allocated treatment for less than 10% of patients in each group. The primary outcome occurred in 36.6% of intervention and 43.4% of usual care participants (relative risk [RR], 0.84 [95% CI, 0.71-1.01]; absolute risk reduction, 6.8% [95% CI, -0.3% to 13.9%]; P = .07). There was no significant difference between groups for any secondary outcomes. Five intervention patients (1.4%) experienced cardiovascular serious adverse events within 24 hours compared with none in the usual care group. Findings of the meta-analysis of 38 trials, including data from this study, suggest that the intervention is associated with fewer complications (intervention, 488/1548 [31.5%] vs control, 614/1476 [41.6%]; RR, 0.77 [95% CI, 0.71-0.83]) and a nonsignificant reduction in hospital, 28-day, or 30-day mortality (intervention, 159/3215 deaths [4.9%] vs control, 206/3160 deaths [6.5%]; RR, 0.82 [95% CI, 0.67-1.01]) and mortality at longest follow-up (intervention, 267/3215 deaths [8.3%] vs control, 327/3160 deaths [10.3%]; RR, 0.86 [95% CI, 0.74-1.00]). In a randomized trial of high-risk patients undergoing major gastrointestinal surgery, use of a cardiac output-guided hemodynamic therapy algorithm compared with usual care did not reduce a composite outcome of complications and 30-day mortality. However, inclusion of these data in an updated meta-analysis indicates that the intervention was associated with a reduction in complication rates. isrctn.org Identifier: ISRCTN04386758.

The rat: a laboratory model for studies of the diving response

PubMed Central

Gan, Qi; Juric, Rajko

2010-01-01

Underwater submersion in mammals induces apnea, parasympathetically mediated bradycardia, and sympathetically mediated peripheral vasoconstriction. These effects are collectively termed the diving response, potentially the most powerful autonomic reflex known. Although these physiological responses are directed by neurons in the brain, study of neural control of the diving response has been hampered since 1) it is difficult to study the brains of animals while they are underwater, 2) feral marine mammals are usually large and have brains of variable size, and 3) there are but few references on the brains of naturally diving species. Similar responses are elicited in anesthetized rodents after stimulation of their nasal mucosa, but this nasopharyngeal reflex has not been compared directly with natural diving behavior in the rat. In the present study, we compared hemodynamic responses elicited in awake rats during volitional underwater submersion with those of rats swimming on the water's surface, rats involuntarily submerged, and rats either anesthetized or decerebrate and stimulated nasally with ammonia vapors. We show that the hemodynamic changes to voluntary diving in the rat are similar to those of naturally diving marine mammals. We also show that the responses of voluntary diving rats are 1) significantly different from those seen during swimming, 2) generally similar to those elicited in trained rats involuntarily “dunked” underwater, and 3) generally different from those seen from dunking naive rats underwater. Nasal stimulation of anesthetized rats differed most from the hemodynamic variables of rats trained to dive voluntarily. We propose that the rat trained to dive underwater is an excellent laboratory model to study neural control of the mammalian diving response, and also suggest that some investigations may be done with nasal stimulation of decerebrate preparations to decipher such control. PMID:20093670

Fluid therapy LiDCO controlled trial-optimization of volume resuscitation of extensively burned patients through noninvasive continuous real-time hemodynamic monitoring LiDCO.

PubMed

Tokarik, Monika; Sjöberg, Folke; Balik, Martin; Pafcuga, Igor; Broz, Ludomir

2013-01-01

This pilot trial aims at gaining support for the optimization of acute burn resuscitation through noninvasive continuous real-time hemodynamic monitoring using arterial pulse contour analysis. A group of 21 burned patients meeting preliminary criteria (age range 18-75 years with second- third- degree burns and TBSA ≥10-75%) was randomized during 2010. A hemodynamic monitoring through lithium dilution cardiac output was used in 10 randomized patients (LiDCO group), whereas those without LiDCO monitoring were defined as the control group. The modified Brooke/Parkland formula as a starting resuscitative formula, balanced crystalloids as the initial solutions, urine output of 0.5 ml/kg/hr as a crucial value of adequate intravascular filling were used in both groups. Additionally, the volume and vasopressor/inotropic support were based on dynamic preload parameters in the LiDCO group in the case of circulatory instability and oligouria. Statistical analysis was done using t-tests. Within the first 24 hours postburn, a significantly lower consumption of crystalloids was registered in LiDCO group (P = .04). The fluid balance under LiDCO control in combination with hourly diuresis contributed to reducing the cumulative fluid balance approximately by 10% compared with fluid management based on standard monitoring parameters. The amount of applied solutions in the LiDCO group got closer to Brooke formula whereas the urine output was at the same level in both groups (0.8 ml/kg/hr). The new finding in this study is that when a fluid resuscitation is based on the arterial waveform analysis, the initial fluid volume provided was significantly lower than that delivered on the basis of physician-directed fluid resuscitation (by urine output and mean arterial pressure).

Splanchnic and renal deterioration during and after laparoscopic cholecystectomy: a comparison of the carbon dioxide pneumoperitoneum and the abdominal wall lift method.

PubMed

Koivusalo, A M; Kellokumpu, I; Ristkari, S; Lindgren, L

1997-10-01

Carbon dioxide (CO2) pneumoperitoneum together with an increased intraabdominal pressure (IAP) induces a hemodynamic stress response, diminishes urine output, and may compromise splanchnic perfusion. A new retractor method may be less traumatic. Accordingly, 30 ASA physical status I or II patients undergoing laparoscopic cholecystectomy were randomly allocated to a CO2 pneumoperitoneum (IAP 12-13 mm Hg) (control) or to a gasless abdominal wall lift method (retractor) group. Anesthesia and intravascular fluids were standardized. Direct mean arterial pressure (MAP), urine output, urine-N-acetyl-beta-D-glucosaminidase (U-NAG), arterial blood gases, gastric mucosal PCO2, and intramucosal pH (pHi) were measured. Normoventilation was instituted in all patients. MAP increased (P < 0.001) only with CO2 pneumoperitoneum. Minute volume of ventilation had to be increased by 35% with CO2 insufflation. PaCO2 was significantly higher (P < 0.05) for 3 h postoperatively in the control group. Diuresis was less (P < 0.01) and U-NAG levels (P < 0.01) higher in the control group. The pHi decreased after induction of pneumoperitoneum up to three hours postoperatively and remained intact in the retractor group. We conclude that the retractor method for laparoscopic cholecystectomy ensures stable hemodynamics, prevents respiratory acidosis, and provides protection against biochemical effects, which reveal the renal and splanchic ischemia caused by CO2 insufflation. A mechanical retractor method (gasless) was compared with conventional CO2 pneumoperitoneum for laparoscopic cholestectomy. The gasless method ensured stable hemodynamics, prevented respiratory acidosis, and provided protection against the renal and splanchnic ischemia seen with CO2 pneumoperitoneum.

Risk factors for readmission after neonatal cardiac surgery.

PubMed

Mackie, Andrew S; Gauvreau, Kimberlee; Newburger, Jane W; Mayer, John E; Erickson, Lars C

2004-12-01

Repeat hospitalizations place a significant burden on health care resources. Factors predisposing infants to unplanned hospital readmission after congenital heart surgery are unknown. This is a single-center, case-control study. Cases were rehospitalized or died within 30 days of discharge following an arterial switch operation (ASO) or Norwood procedure (NP) between 1992 and 2002. Controls underwent an ASO or NP between 1992 and 2002, and were neither readmitted nor died within 30 days of discharge. Patients and controls were matched by gender, year of birth, and procedure. Potential risk factors examined included indices of medical status at the time of discharge, determinants of access to health care, and provider characteristics. Forty-eight patients were readmitted; 19 of 498 (3.8%) following an ASO and 29 of 254 (11.4%) after a NP (p < 0.001). Six infants died within 30 days of discharge; 1 after an ASO and 5 after a NP. In multivariate analysis, predictors of readmission or death were: residual hemodynamic problem(s) (odds ratio [OR] 4.10 [1.18, 14.3], p = 0.026); an intensive care unit stay greater than 7 days (OR 5.17 [1.12, 23.9] p = 0.035) (ASO); residual hemodynamic problem(s) (OR 5.84 [1.98, 17.2], p = 0.001); and establishment of full oral intake less than 2 days before discharge (OR 5.83 [1.83, 18.6], p = 0.003) (NP). Combining both groups, living in a low income Zip Code (< 30,000 dollars/annum) was associated with a lower likelihood of readmission (OR 0.25 [0.07, 0.85], p = 0.027). Residual hemodynamic problem(s) predispose to hospital readmission after the ASO and NP. Low socioeconomic status may reduce the likelihood of readmission even when problems arise.

Effects of Sinoaortic Denervation on Hemodynamic Parameters During Natural Sleep in Rats

PubMed Central

Silveira, Neide P.; Moreira, Edson D.; Drager, Luciano F.; Silva, Gustavo J. J.; Krieger, Eduardo M.

2008-01-01

Study Objectives: To analyze the role of arterial baroreflex on hemodynamic changes during synchronized and desynchronized sleep phases of natural sleep in rats. Design: Experimental study. Setting: Laboratory. Participants: Seventeen male Wistar rats. Interventions: No intervention (control, n = 8) or sinoaortic denervation (SAD, n = 9). Measurements and Results: Sleep phases were monitored by electrocorticogram, and blood pressure was measured directly by a catheter in the carotid artery. Cardiac output, as well as total and regional vascular resistances, were determined by measuring the subdiaphragmatic aorta and iliac artery flows with Doppler flow probes, respectively. In contrast to the control group, the SAD group had a strong reduction in blood pressure (−19.9% ± 2.6% vs −0.7% ± 2.1%) during desynchronized sleep, and cardiac output showed an exacerbated reduction (−10.4% ± 3.5% vs 1.1% ± 1.7%). In SAD rats, total vascular resistance decreased during desynchronized sleep (−10.1% ± 3.5% vs −1.0% ± 1.7%), and the increase in regional vascular resistance observed in the control group was abolished (27.5% ± 8.3% vs −0.8% ± 9.4%). Conclusions: SAD caused profound changes in blood pressure, cardiac output, and total vascular resistance, with a significant increase in muscle vascular resistance during synchronized sleep. Our results suggest that baroreflex plays an important role in maintaining the normal balance of cardiac output and total vascular resistance during sleep. Citation: Silveira NP; Moreira ED; Drager LF; Silva GJJ; Krieger EM. Effects of sinoaortic denervation on hemodynamic parameters during natural sleep in rats. SLEEP 2008;31(3):328-333. PMID:18363308

Effects of chronic treatment with 7-nitroindazole in hyperthyroid rats.

PubMed

Wangensteen, Rosemary; Rodríguez-Gómez, Isabel; Moreno, Juan Manuel; Alvarez-Guerra, Miriam; Osuna, Antonio; Vargas, Félix

2006-11-01

This study analyzed the contribution of neuronal nitric oxide synthase (nNOS) to the hemodynamic manifestations of hyperthyroidism. The effects on hyperthyroid rats of the chronic administration of 7-nitroindazole (7-NI), an inhibitor of nNOS, were studied. Six groups of male Wistar rats were used: control, 7-NI (30 mg.kg-1.day-1 by gavage), T(4)50, T(4)75 (50 or 75 microg thyroxine.rat-1.day-1, respectively), T(4)50+7-NI, and T(4)75+7-NI. All treatments were maintained for 4 wk. Body weight, tail systolic blood pressure (SBP), and heart rate (HR) were recorded weekly. Finally, SBP, pulse pressure (PP), and HR were measured in conscious rats, and morphological, metabolic, plasma, and renal variables were determined. Expression of nNOS in the hypothalamus of T(4)75 and control rats was analyzed by Western blot analysis. The response of mean arterial pressure (MAP) to pentolinium (10 mg/kg iv) was used to evaluate the sympathetic contribution to BP in T(4)75 and T(4)75+7-NI rats. T(4) produced an increased hypothalamic nNOS expression and dose-related increases in blood pressure (BP), HR, and PP vs. control rats. 7-NI did not modify BP or any other hemodynamic variable in normal rats. However, 7-NI produced a marked reduction in BP, HR, PP, and food and water intake in both hyperthyroid groups and improved creatinine clearance in the T(4)75 group. Pentolinium produced a greater MAP decrease in the T(4)75+7-NI than in the T(4)75 group. In conclusion, administration of 7-NI attenuates the hemodynamic and metabolic manifestations of hyperthyroidism, suggesting that nNOS contributes to the hyperdynamic circulation of this endocrine disease by modulating sympathetic activity.

Studying cerebral hemodynamics and metabolism using simultaneous near-infrared spectroscopy and transcranial Doppler ultrasound: a hyperventilation and caffeine study

PubMed Central

Yang, Runze; Brugniaux, Julien; Dhaliwal, Harinder; Beaudin, Andrew E; Eliasziw, Misha; Poulin, Marc J; Dunn, Jeff F

2015-01-01

Caffeine is one of the most widely consumed psycho-stimulants in the world, yet little is known about its effects on brain oxygenation and metabolism. Using a double-blind, placebo-controlled, randomized cross-over study design, we combined transcranial Doppler ultrasound (TCD) and near-infrared spectroscopy (NIRS) to study caffeine's effect on middle cerebral artery peak blood flow velocity (Vp), brain tissue oxygenation (StO2), total hemoglobin (tHb), and cerebral oxygen metabolism (CMRO2) in five subjects. Hyperventilation-induced hypocapnia served as a control to verify the sensitivity of our measurements. During hypocapnia (∼16 mmHg below resting values), Vp decreased by 40.0 ± 2.4% (95% CI, P < 0.001), while StO2 and tHb decreased by 2.9 ± 0.3% and 2.6 ± 0.4%, respectively (P = 0.003 and P = 0.002, respectively). CMRO2, calculated using the Fick equation, was reduced by 29.3 ± 9% compared to the isocapnic-euoxia baseline (P < 0.001). In the pharmacological experiments, there was a significant decrease in Vp, StO2, and tHb after ingestion of 200 mg of caffeine compared with placebo. There was no significant difference in CMRO2 between caffeine and placebo. Both showed a CMRO2 decline compared to baseline showing the importance of a placebo control. In conclusion, this study showed that profound hypocapnia impairs cerebral oxidative metabolism. We provide new insight into the effects of caffeine on cerebral hemodynamics. Moreover, this study showed that multimodal NIRS/TCD is an excellent tool for studying brain hemodynamic responses to pharmacological interventions and physiological challenges. PMID:25907789

Preclinical Evaluation of a Decision Support Medical Monitoring System for Early Detection of Potential Hemodynamic Decompensation During Blood Loss in Humans

DTIC Science & Technology

2013-09-01

Hemodynamic Decompensation During Blood Loss in Humans PRINCIPAL INVESTIGATOR: Michael J. Joyner, M.D. CONTRACTING ORGANIZATION: Mayo Clinic...Medical Monitoring System for Early Detection of Potential Hemodynamic Decompensation During Blood Loss in Humans 5c. PROGRAM ELEMENT NUMBER 6...loss and hemorrhage in humans. The aim Is to be able to detect subtle changes in hemodynamic variables that provide prodromal clues to Impending

Integrating the behavioral and neural dynamics of response selection in a dual-task paradigm: a dynamic neural field model of Dux et al. (2009).

PubMed

Buss, Aaron T; Wifall, Tim; Hazeltine, Eliot; Spencer, John P

2014-02-01

People are typically slower when executing two tasks than when only performing a single task. These dual-task costs are initially robust but are reduced with practice. Dux et al. (2009) explored the neural basis of dual-task costs and learning using fMRI. Inferior frontal junction (IFJ) showed a larger hemodynamic response on dual-task trials compared with single-task trial early in learning. As dual-task costs were eliminated, dual-task hemodynamics in IFJ reduced to single-task levels. Dux and colleagues concluded that the reduction of dual-task costs is accomplished through increased efficiency of information processing in IFJ. We present a dynamic field theory of response selection that addresses two questions regarding these results. First, what mechanism leads to the reduction of dual-task costs and associated changes in hemodynamics? We show that a simple Hebbian learning mechanism is able to capture the quantitative details of learning at both the behavioral and neural levels. Second, is efficiency isolated to cognitive control areas such as IFJ, or is it also evident in sensory motor areas? To investigate this, we restrict Hebbian learning to different parts of the neural model. None of the restricted learning models showed the same reductions in dual-task costs as the unrestricted learning model, suggesting that efficiency is distributed across cognitive control and sensory motor processing systems.

Computational fluid dynamics (CFD) using porous media modeling predicts recurrence after coiling of cerebral aneurysms

PubMed Central

Ishida, Fujimaro; Tsuji, Masanori; Furukawa, Kazuhiro; Shiba, Masato; Yasuda, Ryuta; Toma, Naoki; Sakaida, Hiroshi; Suzuki, Hidenori

2017-01-01

Objective This study aimed to predict recurrence after coil embolization of unruptured cerebral aneurysms with computational fluid dynamics (CFD) using porous media modeling (porous media CFD). Method A total of 37 unruptured cerebral aneurysms treated with coiling were analyzed using follow-up angiograms, simulated CFD prior to coiling (control CFD), and porous media CFD. Coiled aneurysms were classified into stable or recurrence groups according to follow-up angiogram findings. Morphological parameters, coil packing density, and hemodynamic variables were evaluated for their correlations with aneurysmal recurrence. We also calculated residual flow volumes (RFVs), a novel hemodynamic parameter used to quantify the residual aneurysm volume after simulated coiling, which has a mean fluid domain > 1.0 cm/s. Result Follow-up angiograms showed 24 aneurysms in the stable group and 13 in the recurrence group. Mann-Whitney U test demonstrated that maximum size, dome volume, neck width, neck area, and coil packing density were significantly different between the two groups (P < 0.05). Among the hemodynamic parameters, aneurysms in the recurrence group had significantly larger inflow and outflow areas in the control CFD and larger RFVs in the porous media CFD. Multivariate logistic regression analyses demonstrated that RFV was the only independently significant factor (odds ratio, 1.06; 95% confidence interval, 1.01–1.11; P = 0.016). Conclusion The study findings suggest that RFV collected under porous media modeling predicts the recurrence of coiled aneurysms. PMID:29284057

Anterior Borderzone Angle for Hemodynamic Collateral Metric in Patients with Symptomatic Middle Cerebral Artery Stenosis.

PubMed

Li, Yongkun; Xiong, Yunyun; Cai, Qiankun; Liu, Dezhi; Dai, Qiliang; Liu, Wenhua; Huang, Zhixin; Sun, Wen; Liebeskind, David S; Wang, Yinzhou; Liu, Xinfeng

2018-01-01

We aimed to introduce a parameter of anterior borderzone angle (ABZA) to quantitatively evaluate the ACA-MCA leptomeningeal collaterals for middle cerebral artery stenosis (MCAS). Two hundred seventy-five patients with 50-100% MCAS and 100 controls were included. The 95% reference range of ABZA was obtained from the controls. ABZAtrans was defined as "ABZA/the 95% upper limit." Relationships between ABZA and MCAS, -ABZAtrans and the TICI grade, the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) collateral grade were analyzed. An ABZA grade model for the ACA leptomeningeal collaterals was tentatively developed. The 95% reference range of ABZA was 0.0º-23.0º. ABZA was significantly associated with MCAS by a function of the fourth power (R2 = 0.723, p < 0.001), and could predict hemodynamic MCAS (≥70%) with an AUC of 0.928 (95% CI 0.903-0.953). ABZAtrans was negatively correlated with the TICI grade (rho = -0.752, p < 0.001) and positively with the ASITN/SIR grade (rho = 0.921, p < 0.001). The ABZA grade was created by rounding -ABZAtrans to a nearest integer, and was closely associated with the ASITN/SIR grade (rho = 0.894, p < 0.001). ABZA can be used as a hemodynamic parameter to quantitatively evaluate ACA leptomeningeal collaterals. © 2017 S. Karger AG, Basel.

Utility of N-terminal pro-brain natriuretic peptide for assessing hemodynamic significance of patent ductus arteriosus in dogs undergoing ductal repair.

PubMed

Hariu, Crystal D; Saunders, Ashley B; Gordon, Sonya G; Norby, Bo; Miller, Matthew W

2013-09-01

Determine if plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) correlates with markers of hemodynamically significant patent ductus arteriosus (PDA) in dogs. Ten dogs with PDA and 30 healthy dogs of similar ages. Prospective case series with control population. Dogs with PDA were initially evaluated with thoracic radiographs, transthoracic echocardiography, pulmonary capillary wedge pressure (PCWP) and NT-proBNP. Following ductal occlusion, NT-proBNP and echocardiography were repeated within 24 h and at day 90. PCWP was repeated at day 90. Correlation between NT-proBNP and hemodynamic measurements was assessed, and accuracy of NT-proBNP for identifying PDA severity was estimated. NT-proBNP was significantly higher (median; absolute range) in dogs with PDA (895; 490-7118 pmol/L) than controls (663; 50-1318 pmol/L) (p = 0.025). NT-proBNP decreased significantly 90 days post-ductal closure (597; 154-1858 pmol/L) (p = 0.013). Left atrial and ventricular size decreased significantly within 24 h and at day 90 as did PCWP (day 90 only). NT-proBNP correlated with vertebral heart size (VHS) and indexed left ventricular systolic diameter (iLVIDs); concentrations ≥ 1224 pmol/L distinguished dogs with elevated VHS and iLVIDs. NT-proBNP is elevated in dogs with PDA, decreases following PDA closure and correlates with select radiographic and echocardiographic markers of cardiac remodeling. Copyright © 2013 Elsevier B.V. All rights reserved.

Effects of obstructive sleep apnea on hemodynamic parameters in patients entering cardiac rehabilitation.

PubMed

Hargens, Trent A; Aron, Adrian; Newsome, Laura J; Austin, Joseph L; Shafer, Brooke M

2015-01-01

Obstructive sleep apnea (OSA) is a prevalent form of sleep-disordered breathing. Evidence suggests that OSA may lead to cardiac remodeling, although the literature is equivocal. Previous literature suggests a high percentage of individuals entering a cardiac rehabilitation (CR) program also have OSA. The objective of this study was to determine whether resting hemodynamic variables were altered in OSA subjects entering CR compared with those without OSA, as determined by impedance cardiography. Subjects entering an early outpatient CR program were screened for OSA using an at-home screening device and verified by a sleep physician. Subjects were divided into an OSA group (n = 48) or a control group (n = 25) on the basis of the screening results. Hemodynamic variables were measured during supine rest using impedance cardiography. A 6-minute walk test was performed to assess functional capacity. The proportion of cardiac diagnoses was similar between groups. Overall, 66% of the subjects were positive for OSA. Subject groups did not differ by age, body mass index, heart rate, diastolic blood pressure, or functional capacity. Cardiac output, cardiac index, stroke volume, contractility index, and left cardiac work index were all significantly decreased in the OSA group compared with the control group (P < .05). Findings suggest that OSA results in decreased cardiac function in patients entering CR, likely because of pressure and volume changes associated with apneic events. This may place those individuals at a disadvantage in recovering from their cardiac event, and place them at increased risk for secondary complications.

Cerebral Hemodynamics During Exercise and Recovery in Heart Transplant Recipients.

PubMed

Gayda, Mathieu; Desjardins, Audrey; Lapierre, Gabriel; Dupuy, Olivier; Fraser, Sarah; Bherer, Louis; Juneau, Martin; White, Michel; Gremeaux, Vincent; Labelle, Véronique; Nigam, Anil

2016-04-01

The aims of this work were (1) to compare cerebral oxygenation-perfusion (COP), central hemodynamics, and peak oxygen uptake (V˙o2peak) in heart transplant recipients (HTRs) vs age-matched healthy controls (AMHCs) during exercise and recovery and (2) to study the relationships between COP, central hemodynamics, and V˙o2peak in HTRs and AMHCs. Twenty-six HTRs (3 women) and 27 AMHCs (5 women) were recruited. Maximal cardiopulmonary function (gas exchange analysis), cardiac hemodynamics (impedance cardiography), and left frontal COP (near-infrared spectroscopy) were measured continuously during and after a maximal ergocycle (Ergoline 800S, Bitz, Germany) test. Compared with AMHCs, HTRs had lower V˙o2peak, maximal cardiac index (CImax), and maximal ventilatory variables (P < 0.05). COP was lower during exercise (oxyhemoglobin [ΔO2Hb], 50% and 75% of V˙O2peak, total hemoglobin [ΔtHb], 100% of V˙O2peak; P < 0.05), and recovery in HTRs (ΔO2Hb, minutes 2-5; ΔtHb, minutes 1-5; P < 0.05) compared with AMHCs. End-tidal pressure of CO2 was lower during exercise compared with that in AMHCs (P < 0.0001). In HTRs, CImax was positively correlated with exercise cerebral hemodynamics (R = 0.54-0.60; P < 0.01). In HTRs, COP was reduced during exercise and recovery compared with that in AMHCs, potentially because of a combination of blunted cerebral vasodilation by CO2, cerebrovascular dysfunction, reduced cardiac function, and medication. The impaired V˙O2peak observed in HTRs was mainly caused by reduced maximal ventilation and CI. In HTRs, COP is impaired and is correlated with cardiac function, potentially impacting cognitive function. Therefore, we need to study which interventions (eg, exercise training) are most effective for improving or normalizing (or both) COP during and after exercise in HTRs. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Decoupling the effect of shear stress and stretch on tissue growth & remodeling in a vascular graft.

PubMed

van Haaften, Eline E; Wissing, Tamar B; Rutten, Marcel; Bulsink, Jurgen A; Gashi, Kujtim; van Kelle, Mathieu A J; Smits, Anthal; Bouten, Carlijn; Kurniawan, Nicholas A

2018-06-07

The success of cardiovascular tissue engineering strategies largely depends on the mechanical environment in which cells develop a neo-tissue via growth and remodeling processes. This mechanical environment is defined by the local scaffold architecture to which cells adhere, i.e., the micro-environment, and by external mechanical cues to which cells respond, i.e., hemodynamic loading. The hemodynamic environment of early-developing blood vessels consists of both shear stress (due to blood flow) and circumferential stretch (due to blood pressure). Experimental platforms that recapitulate this mechanical environment in a controlled and tunable manner are thus critical for investigating cardiovascular tissue engineering. In traditional perfusion bioreactors, however, shear stress and stretch are coupled, hampering a clear delineation of their effects on cell and tissue response. Here, we uniquely designed a bioreactor that independently combines these two types of mechanical cues in eight parallel vascular grafts. The system is computationally and experimentally validated, through finite element analysis and culture of tissue constructs respectively, to distinguish various levels of shear stress (up to 5 Pa) and cyclic stretch (up to 1.10). To illustrate the usefulness of the system, we investigated the relative contribution of cyclic stretch (1.05 at 0.5 Hz) and shear stress (1 Pa) to tissue development. Both types of hemodynamic loading contributed to cell alignment, but the contribution of shear stress overruled stretch-induced cell proliferation and matrix (i.e., collagen and glycosaminoglycan) production. At a macroscopic level, cyclic stretching led to the most linear stress-stretch response, which was not related to the presence of shear stress. In conclusion, we have developed a bioreactor that is particularly suited to further unravel the interplay between hemodynamics and in situ tissue engineering processes. Using the new system, the present work highlights the importance of hemodynamic loading to the study of developing vascular tissues.

Effects of Direct Renin Blockade on Renal & Systemic Hemodynamics and on RAAS Activity, in Weight Excess and Hypertension: A Randomized Clinical Trial

PubMed Central

Kwakernaak, A. J.; Roksnoer, L. C.; Lambers Heerspink, H. J.; van den Berg-Garrelds, I.; Lochorn, G. A.; van Embden Andres, J. H.; Klijn, M. A.; Kobori, H.; Danser, A. H. J.; Laverman, G. D.; Navis, G. J.

2017-01-01

Aim The combination of weight excess and hypertension significantly contributes to cardiovascular risk and progressive kidney damage. An unfavorable renal hemodynamic profile is thought to contribute to this increased risk and may be ameliorated by direct renin inhibition (DRI). The aim of this trial was to assess the effect of DRI on renal and systemic hemodynamics and on RAAS activity, in men with weight excess and hypertension. Methods A randomized, double-blind, cross-over clinical trial to determine the effect of DRI (aliskiren 300 mg/day), with angiotensin converting enzyme inhibition (ACEi; ramipril 10 mg/day) as a positive control, on renal and systemic hemodynamics, and on RAAS activity (n = 15). Results Mean (SEM) Glomerular filtration rate (101 (5) mL/min/1.73m2) remained unaffected by DRI or ACEi. Effective renal plasma flow (ERPF; 301 (14) mL/min/1.73m2) was increased in response to DRI (320 (14) mL/min/1.73m2, P = 0.012) and ACEi (317 (15) mL/min/1.73m2, P = 0.045). Filtration fraction (FF; 34 (0.8)%) was reduced by DRI only (32 (0.7)%, P = 0.044). Mean arterial pressure (109 (2) mmHg) was reduced by DRI (101 (2) mmHg, P = 0.008) and ACEi (103 (3) mmHg, P = 0.037). RAAS activity was reduced by DRI and ACEi. Albuminuria (20 [9–42] mg/d) was reduced by DRI only (12 [5–28] mg/d, P = 0.030). Conclusions In men with weight excess and hypertension, DRI and ACEi improved renal and systemic hemodynamics. Both DRI and ACEi reduced RAAS activity. Thus, DRI provides effective treatment in weight excess and hypertension. Trial Registration Dutch trial register, registration number: 2532 www.trialregister.nl PMID:28118402

Early detection of endothelial injury and dysfunction in conjunction with correction of hemodynamic maladjustment can effectively restore renal function in type 2 diabetic nephropathy.

PubMed

Futrakul, Narisa; Butthep, Punnee; Vongthavarawat, Varaphon; Futrakul, Prasit; Sirisalipoch, Sasitorn; Chaivatanarat, Tawatchai; Suwanwalaikorn, Sompongse

2006-01-01

This paper was aimed to investigate (1) the early marker of endothelial injury in type 2 diabetes, (2) the intrarenal hemodynamics and renal function, and (3) the therapeutic strategy aiming to restore renal function. Fifty patients (35 normoalbuminuric and 15 albuminuric type 2 diabetes) were examined. Blood was collected for determination of circulating vascular endothelial cells (CEC) and the serum was prepared for determination of transforming growth factor beta (TGFbeta), ratio of CEC/TGFbeta, and soluble vascular cell adhesion molecule. Intrarenal hemodynamics and renal function were also assessed. The results showed that increased number of circulating EC, elevated TGFbeta and depleted ratio of CEC/TGFbeta were significantly observed. Intrarenal hemodynamic study revealed a hemodynamic maladjustment characterized by preferential constriction of the efferent arteriole, intraglomerular hypertension and reduction in peritubular capillary flow. It was concluded that early marker of endothelial injury is reflected by increasing number of CEC. Such markers correlate with the glomerular endothelial dysfunction associated with hemodynamic maladjustment. Early detection of endothelial injury and appropriate correction of hemodynamic maladjustment by multidrug vasodilators can effectively restore renal function in type 2 diabetic nephropathy.

Identification of High-Risk Plaques Destined to Cause Acute Coronary Syndrome Using Coronary Computed Tomographic Angiography and Computational Fluid Dynamics.

PubMed

Lee, Joo Myung; Choi, Gilwoo; Koo, Bon-Kwon; Hwang, Doyeon; Park, Jonghanne; Zhang, Jinlong; Kim, Kyung-Jin; Tong, Yaliang; Kim, Hyun Jin; Grady, Leo; Doh, Joon-Hyung; Nam, Chang-Wook; Shin, Eun-Seok; Cho, Young-Seok; Choi, Su-Yeon; Chun, Eun Ju; Choi, Jin-Ho; Nørgaard, Bjarne L; Christiansen, Evald H; Niemen, Koen; Otake, Hiromasa; Penicka, Martin; de Bruyne, Bernard; Kubo, Takashi; Akasaka, Takashi; Narula, Jagat; Douglas, Pamela S; Taylor, Charles A; Kim, Hyo-Soo

2018-03-14

We investigated the utility of noninvasive hemodynamic assessment in the identification of high-risk plaques that caused subsequent acute coronary syndrome (ACS). ACS is a critical event that impacts the prognosis of patients with coronary artery disease. However, the role of hemodynamic factors in the development of ACS is not well-known. Seventy-two patients with clearly documented ACS and available coronary computed tomographic angiography (CTA) acquired between 1 month and 2 years before the development of ACS were included. In 66 culprit and 150 nonculprit lesions as a case-control design, the presence of adverse plaque characteristics (APC) was assessed and hemodynamic parameters (fractional flow reserve derived by coronary computed tomographic angiography [FFR CT ], change in FFR CT across the lesion [△FFR CT ], wall shear stress [WSS], and axial plaque stress) were analyzed using computational fluid dynamics. The best cut-off values for FFR CT , △FFR CT , WSS, and axial plaque stress were used to define the presence of adverse hemodynamic characteristics (AHC). The incremental discriminant and reclassification abilities for ACS prediction were compared among 3 models (model 1: percent diameter stenosis [%DS] and lesion length, model 2: model 1 + APC, and model 3: model 2 + AHC). The culprit lesions showed higher %DS (55.5 ± 15.4% vs. 43.1 ± 15.0%; p < 0.001) and higher prevalence of APC (80.3% vs. 42.0%; p < 0.001) than nonculprit lesions. Regarding hemodynamic parameters, culprit lesions showed lower FFR CT and higher △FFR CT , WSS, and axial plaque stress than nonculprit lesions (all p values <0.01). Among the 3 models, model 3, which included hemodynamic parameters, showed the highest c-index, and better discrimination (concordance statistic [c-index] 0.789 vs. 0.747; p = 0.014) and reclassification abilities (category-free net reclassification index 0.287; p = 0.047; relative integrated discrimination improvement 0.368; p < 0.001) than model 2. Lesions with both APC and AHC showed significantly higher risk of the culprit for subsequent ACS than those with no APC/AHC (hazard ratio: 11.75; 95% confidence interval: 2.85 to 48.51; p = 0.001) and with either APC or AHC (hazard ratio: 3.22; 95% confidence interval: 1.86 to 5.55; p < 0.001). Noninvasive hemodynamic assessment enhanced the identification of high-risk plaques that subsequently caused ACS. The integration of noninvasive hemodynamic assessments may improve the identification of culprit lesions for future ACS. (Exploring the Mechanism of Plaque Rupture in Acute Coronary Syndrome Using Coronary CT Angiography and Computational Fluid Dynamic [EMERALD]; NCT02374775). Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Using impedance cardiography with postural change to stratify patients with hypertension.

PubMed

DeMarzo, Arthur P

2011-06-01

Early detection of cardiovascular disease in patients with hypertension could initiate appropriate treatment to control blood pressure and prevent the progression of cardiovascular disease. The goal of this study was to show how impedance cardiography waveform analysis with postural change can be used to detect subclinical cardiovascular disease in patients with high blood pressure. Patients with high blood pressure had impedance cardiography data obtained in two positions, standing upright and supine. In 50 adults, impedance cardiography indicated that all patients had abnormal data, with 44 (88%) having multiple abnormalities. Impedance cardiography showed 32 (64%) had ventricular dysfunction, 48 (96%) had vascular load abnormalities, 34 (68%) had hemodynamic abnormalities, 2 (4%) had hypovolemia, and 3 (6%) had hypervolemia. Hypertensive patients have diverse cardiovascular abnormalities that can be quantified by impedance cardiography. By stratifying patients with ventricular, vascular, and hemodynamic abnormalities, treatment could be customized based on the abnormal underlying mechanisms with the potential to rapidly control blood pressure, prevent progression of cardiovascular disease, and possibly reverse remodeling.

Hemodynamic, ventilatory, and biochemical responses of panic patients and normal controls with sodium lactate infusion and spontaneous panic attacks.

PubMed

Gaffney, F A; Fenton, B J; Lane, L D; Lake, C R

1988-01-01

Hemodynamic, ventilatory, and biochemical variables were measured in ten healthy adults and ten panic patients during infusion of 0.5 mol/L of sodium lactate. Physical activity, fitness level, and ambulatory electrocardiograms were also recorded. Lactate infusion doubled cardiac output, increased blood lactate levels by sixfold, and produced hypernatremia, hypocalcemia, and decreased serum bicarbonate levels in both groups but raised arterial pressure only in the patients. The patients hyperventilated before and during the infusion. Physiological responses and somatic complaints with the infusion differed little between the groups, but emotional complaints were six times more frequent among the panic patients. Eight patients but no control subjects interpreted their symptoms as a panic attack. Heart rate increased with only 14 of 31 recorded spontaneous outpatient panic attacks. Sodium lactate infusions appear to produce panic by mimicking the physiology of spontaneous panic. Treatment with cardioactive agents is not indicated in the absence of cardiopulmonary or autonomic nervous system abnormalities.

Fetal Intervention in Right Outflow Tract Obstructive Disease: Selection of Candidates and Results

PubMed Central

Gómez Montes, E.; Herraiz, I.; Mendoza, A.; Galindo, A.

2012-01-01

Objectives. To describe the process of selection of candidates for fetal cardiac intervention (FCI) in fetuses diagnosed with pulmonary atresia-critical stenosis with intact ventricular septum (PA/CS-IVS) and report our own experience with FCI for such disease. Methods. We searched our database for cases of PA/CS-IVS prenatally diagnosed in 2003–2012. Data of 38 fetuses were retrieved and analyzed. FCI were offered to 6 patients (2 refused). In the remaining it was not offered due to the presence of either favourable prognostic echocardiographic markers (n = 20) or poor prognostic indicators (n = 12). Results. The outcome of fetuses with PA/CS-IVS was accurately predicted with multiparametric scoring systems. Pulmonary valvuloplasty was technically successful in all 4 fetuses. The growth of the fetal right heart and hemodynamic parameters showed a Gaussian-like behaviour with an improvement in the first weeks and slow worsening as pregnancy advanced, probably indicating a restenosis. Conclusions. The most likely type of circulation after birth may be predicted in the second trimester of pregnancy by means of combining cardiac dimensions and functional parameters. Fetal pulmonary valvuloplasty in midgestation is technically feasible and in well-selected cases may improve right heart growth, fetal hemodynamics, and postnatal outcome. PMID:22928144

Cerebrovascular Complications After Heart Transplantation

PubMed Central

Alejaldre, Aída; Delgado-Mederos, Raquel; Santos, Miguel Ángel; Martí-Fàbregas, Joan

2010-01-01

Neurological complications in orthotopic heart transplantation represent a major cause of morbidity and mortality despite successful transplantation. The most frequent perioperative neurological complications are delirium or encephalopathy. In this period cerebrovascular complication ranges between 5-11%. After the perioperative period, the 5-year stroke risk after cardiac transplantation is 4.1%. In a retrospective study conducted with 314 patients who underwent cardiac transplantation, it was found that 20% of cerebrovascular complications occurred within the first two weeks after transplantation, while 80% occurred in the late postoperative phase. Of these, ischemic stroke is the most common subtype. In the perioperative periode, hemodynamic instability, cardiac arrest, extracorporeal circulation over 2 hours, prior history of stroke, and carotid stenosis greater than 50% have been reported to be risk factors for the occurrence of cerebrovascular complications. Perioperative cerebrovascular complications are associated with higher mortality and poor functional outcome at one year follow-up. After the perioperative period, the only factor that has been significantly associated with an increased risk of cerebrovascular complications is a history of prior stroke, either ischemic or hemorrhagic. Other associated factors include unknown atrial fibrillation, septic emboli from endocarditis, cardiac catheterization and perioperative hemodynamic shock. According to the TOAST etiologic classification, the most prevalent etiologic subtype of ischemic stroke is undetermined cause. PMID:21804780

Novel use of a noninvasive hemodynamic monitor in a personalized, active learning simulation.

PubMed

Zoller, Jonathan K; He, Jianghua; Ballew, Angela T; Orr, Walter N; Flynn, Brigid C

2017-06-01

The present study furthered the concept of simulation-based medical education by applying a personalized active learning component. We tested this novel approach utilizing a noninvasive hemodynamic monitor with the capability to measure and display in real time numerous hemodynamic parameters in the exercising participant. Changes in medical knowledge concerning physiology were examined with a pre-and posttest. Simply by observation of one's own hemodynamic variables, the understanding of complex physiological concepts was significantly enhanced. Copyright © 2017 the American Physiological Society.

New tools for optimizing fluid resuscitation in acute pancreatitis

PubMed Central

Bortolotti, Perrine; Saulnier, Fabienne; Colling, Delphine; Redheuil, Alban; Preau, Sebastien

2014-01-01

Acute pancreatitis (AP) is a frequent disease with degrees of increasing severity responsible for high morbidity. Despite continuous improvement in care, mortality remains significant. Because hypovolemia, together with microcirculatory dysfunction lead to poor outcome, fluid therapy remains a cornerstone of the supportive treatment. However, poor clinical evidence actually support the aggressive fluid therapy recommended in recent guidelines since available data are controversial. Fluid management remains unclear and leads to current heterogeneous practice. Different strategies may help to improve fluid resuscitation in AP. On one hand, integration of fluid therapy in a global hemodynamic resuscitation has been demonstrated to improve outcome in surgical or septic patients. Tailored fluid administration after early identification of patients with high-risk of poor outcome presenting inadequate tissue oxygenation is a major part of this strategy. On the other hand, new decision parameters have been developed recently to improve safety and efficiency of fluid therapy in critically ill patients. In this review, we propose a personalized strategy integrating these new concepts in the early fluid management of AP. This new approach paves the way to a wide range of clinical studies in the field of AP. PMID:25473163

Clinical Implications of Cluster Analysis-Based Classification of Acute Decompensated Heart Failure and Correlation with Bedside Hemodynamic Profiles.

PubMed

Ahmad, Tariq; Desai, Nihar; Wilson, Francis; Schulte, Phillip; Dunning, Allison; Jacoby, Daniel; Allen, Larry; Fiuzat, Mona; Rogers, Joseph; Felker, G Michael; O'Connor, Christopher; Patel, Chetan B

2016-01-01

Classification of acute decompensated heart failure (ADHF) is based on subjective criteria that crudely capture disease heterogeneity. Improved phenotyping of the syndrome may help improve therapeutic strategies. To derive cluster analysis-based groupings for patients hospitalized with ADHF, and compare their prognostic performance to hemodynamic classifications derived at the bedside. We performed a cluster analysis on baseline clinical variables and PAC measurements of 172 ADHF patients from the ESCAPE trial. Employing regression techniques, we examined associations between clusters and clinically determined hemodynamic profiles (warm/cold/wet/dry). We assessed association with clinical outcomes using Cox proportional hazards models. Likelihood ratio tests were used to compare the prognostic value of cluster data to that of hemodynamic data. We identified four advanced HF clusters: 1) male Caucasians with ischemic cardiomyopathy, multiple comorbidities, lowest B-type natriuretic peptide (BNP) levels; 2) females with non-ischemic cardiomyopathy, few comorbidities, most favorable hemodynamics; 3) young African American males with non-ischemic cardiomyopathy, most adverse hemodynamics, advanced disease; and 4) older Caucasians with ischemic cardiomyopathy, concomitant renal insufficiency, highest BNP levels. There was no association between clusters and bedside-derived hemodynamic profiles (p = 0.70). For all adverse clinical outcomes, Cluster 4 had the highest risk, and Cluster 2, the lowest. Compared to Cluster 4, Clusters 1-3 had 45-70% lower risk of all-cause mortality. Clusters were significantly associated with clinical outcomes, whereas hemodynamic profiles were not. By clustering patients with similar objective variables, we identified four clinically relevant phenotypes of ADHF patients, with no discernable relationship to hemodynamic profiles, but distinct associations with adverse outcomes. Our analysis suggests that ADHF classification using simultaneous considerations of etiology, comorbid conditions, and biomarker levels, may be superior to bedside classifications.

Central hemodynamic responses during serial exercise tests in heart failure patients using implantable hemodynamic monitors.

PubMed

Ohlsson, A; Steinhaus, D; Kjellström, B; Ryden, L; Bennett, T

2003-06-01

Exercise testing is commonly used in patients with congestive heart failure for diagnostic and prognostic purposes. Such testing may be even more valuable if invasive hemodynamics are acquired. However, this will make the test more complex and expensive and only provides information from isolated moments. We studied serial exercise tests in heart failure patients with implanted hemodynamic monitors allowing recording of central hemodynamics. Twenty-one NYHA Class II-III heart failure patients underwent maximal exercise tests and submaximal bike or 6-min hall walk tests to quantify their hemodynamic responses and to study the feasibility of conducting exercise tests in patients with such devices. Patients were followed for 2-3 years with serial exercise tests. During maximal tests (n=70), heart rate increased by 52+/-19 bpm while S(v)O(2) decreased by 35+/-10% saturation units. RV systolic and diastolic pressure increased 29+/-11 and 11+/-6 mmHg, respectively, while pulmonary artery diastolic pressure increased 21+/-8 mmHg. Submaximal bike (n=196) and hall walk tests (n=172) resulted in S(v)O(2) changes of 80 and 91% of the maximal tests, while RV pressures ranged from 72 to 79% of maximal responses. An added potential value of implantable hemodynamic monitors in heart failure patients may be to quantitatively determine the true hemodynamic profile during standard non-invasive clinical exercise tests and to compare that to hemodynamic effects of regular exercise during daily living. It would be of interest to study whether such information could improve the ability to predict changes in a patient's clinical condition and to improve tailoring patient management.

Abdominal Aortic Hemodynamics in Intermittent Claudication Patients at Rest and During Dynamic Pedaling Exercise

PubMed Central

Cheng, Christopher P.; Taylor, Charles A.; Dalman, Ronald L.

2015-01-01

Introduction Lower extremity exercise has been shown to eliminate adverse hemodynamics conditions, such as low and oscillating blood flow and wall shear stress, in the abdominal aortas of healthy young and older adults. Methods We use cine phase-contrast magnetic resonance imaging and a custom MRI-compatible exercise cycle to quantify hemodynamic changes due to pedaling exercise in patients diagnosed with intermittent claudication. Results and Conclusions With only an average heart increase of 35±18% and exercise workload of 36±16 Watts, the patients experienced approximately 3- and 6-fold increases in blood flow, and 4- and 16-fold increases in wall shear stress at the supraceliac and infrarenal aortic locations, respectively. Also, all oscillations in flow and shear stress at rest were eliminated with exercise. Claudication patients experience 3 to 4-fold lower oscillations in flow and shear stress at rest as compared to healthy age-matched controls, likely due to reduced distal arterial compliance as a result of distal atherosclerosis. The magnitude of flow and shear oscillatory indices may be good indicators of distal arterial compliance and health, and may provide predictive power for the efficacy of focal interventions. PMID:26315797

Effects of exercise training on pulmonary hemodynamics, functional capacity and inflammation in pulmonary hypertension

PubMed Central

Richter, Manuel J.; Grimminger, Jan; Krüger, Britta; Ghofrani, Hossein A.; Mooren, Frank C.; Gall, Henning; Pilat, Christian; Krüger, Karsten

2017-01-01

Pulmonary hypertension (PH) is characterized by severe exercise limitation mainly attributed to the impairment of right ventricular function resulting from a concomitant elevation of pulmonary vascular resistance and pressure. The unquestioned cornerstone in the management of patients with pulmonary arterial hypertension (PAH) is specific vasoactive medical therapy to improve pulmonary hemodynamics and strengthen right ventricular function. Nevertheless, evidence for a beneficial effect of exercise training (ET) on pulmonary hemodynamics and functional capacity in patients with PH has been growing during the past decade. Beneficial effects of ET on regulating factors, inflammation, and metabolism have also been described. Small case-control studies and randomized clinical trials in larger populations of patients with PH demonstrated substantial improvements in functional capacity after ET. These findings were accompanied by several studies that suggested an effect of ET on inflammation, although a direct link between this effect and the therapeutic benefit of ET in PH has not yet been demonstrated. On this background, the aim of the present review is to describe current concepts regarding the effects of exercise on the pulmonary circulation and pathophysiological limitations, as well as the clinical and mechanistic effects of exercise in patients with PH. PMID:28680563

Low central venous pressure with milrinone during living donor hepatectomy.

PubMed

Ryu, H-G; Nahm, F S; Sohn, H-M; Jeong, E-J; Jung, C-W

2010-04-01

Maintaining a low central venous pressure (CVP) has been frequently used in liver resections to reduce blood loss. However, decreased preload carries potential risks such as hemodynamic instability. We hypothesized that a low CVP with milrinone would provide a better surgical environment and hemodynamic stability during living donor hepatectomy. Thirty-eight healthy adult liver donors were randomized to receive either milrinone (milrinone group, n = 19) or normal saline (control group, n = 19) infusion during liver resection. The surgical field was assessed using a four-point scale. Intraoperative vital signs, blood loss, the use of vasopressors and diuretics and postoperative laboratory data were compared between groups. The milrinone group showed a superior surgical field (p < 0.001) and less blood loss (142 +/- 129 mL vs. 378 +/- 167 mL, p < 0.001). Vital signs were well maintained in both groups but the milrinone group required smaller amounts of vasopressors and less-frequent diuretics to maintain a low CVP. The milrinone group also showed a more rapid recovery pattern after surgery. Milrinone-induced low CVP improves the surgical field with less blood loss during living donor hepatectomy and also has favorable effects on intraoperative hemodynamics and postoperative recovery.

Simultaneous EEG and diffuse optical imaging of seizure-related hemodynamic activity in the newborn infant brain

NASA Astrophysics Data System (ADS)

Hebden, Jeremy C.; Cooper, Robert J.; Gibson, Adam; Everdell, Nick; Austin, Topun

2012-06-01

An optical imaging system has been developed which uses measurements of diffusely reflected near-infrared light to produce maps of changes in blood flow and oxygenation occurring within the cerebral cortex. Optical sources and detectors are coupled to the head via an array of optical fibers, on a probe held in contact with the scalp, and data is collected at a rate of 10 Hz. A clinical electroencephalography (EEG) system has been integrated with the optical system to enable simultaneous observation of electrical and hemodynamic activity in the cortex of neurologically compromised newborn infants diagnosed with seizures. Studies have made a potentially critically important discovery of previously unknown transient hemodynamic events in infants treated with anticonvulsant medication. We observed repeated episodes of small increases in cortical oxyhemoglobin concentration followed by a profound decrease in 3 of 4 infants studied, each with cerebral injury who presented with neonatal seizures. This was not accompanied by clinical or EEG seizure activity and was not present in nineteen matched controls. The underlying cause of these changes is currently unknown. We tentatively suggest that our results may be associated with a phenomenon known as cortical spreading depolarization, not previously observed in the infant brain.

Utility and Clinical Profile of Dexmedetomidine in Pediatric Cardiac Catheterization Procedures: A Matched Controlled Analysis.

PubMed

Riveros, Ricardo; Makarova, Natalya; Riveros-Perez, Efrain; Chodavarapu, Praneeta; Saasouh, Wael; Yılmaz, Hüseyin Oğuz; Cuko, Evis; Babazade, Rovnat; Kimatian, Stephen; Turan, Alparslan

2017-12-01

Dexmedetomidine is increasingly used in children undergoing cardiac catheterization procedures. We compared the percentage of surgical time with hemodynamic instability and the incidence of postoperative agitation between pediatric cardiac catheterization patients who received dexmedetomidine infusion and those who did not and the incidence of postoperative agitation. We matched 653 pediatric patients scheduled for cardiac catheterization. Two separate multivariable linear mixed models were used to assess the association between dexmedetomidine use and intraoperative blood pressure and heart rate instability. A multivariate logistic regression was used for relationship between dexmedetomidine and postoperative agitation. No difference between the study groups was found in the duration of MAP ( P = .867) or heart rate (HR) instabilities ( P = .224). The relationship between dexmedetomidine use and the duration of negative hemodynamic effects does not depend on any of the considered CHD types (all P > .001) or intervention ( P = .453 for MAP and P = .023 for HR). No difference in postoperative agitation was found between the study groups ( P = .590). Our study demonstrated no benefit in using dexmedetomidine infusion compared with other general anesthesia techniques to maintain hemodynamic stability or decrease agitation in pediatric patients undergoing cardiac catheterization procedures.

Acid-base disturbance in patients with cirrhosis: relation to hemodynamic dysfunction.

PubMed

Henriksen, Jens H; Bendtsen, Flemming; Møller, Søren

2015-08-01

Acid-base disturbances were investigated in patients with cirrhosis in relation to hemodynamic derangement to analyze the hyperventilatory effects and the metabolic compensation. A total of 66 patients with cirrhosis and 44 controls were investigated during a hemodynamic study. Hyperventilatory hypocapnia was present in all patients with cirrhosis and progressed from Child class A to C (P<0.01). Arterial pH increased significantly from class A to C (P<0.001) and was correlated inversely to the mean arterial blood pressure (r=-0.30, P<0.02), systemic vascular resistance (r=-0.25, P<0.05), indocyanine green clearance (r=-0.37, P<0.005), and serum sodium (r=-0.38, P<0.002). Metabolic compensation was shown by a reduced standard base excess in all patients (P<0.001). Standard base excess contained elements related to changes in serum albumin, water dilution, and effects of unidentified ions (all P<0.001). A significant hepatic component in the acid-base disturbances could not be identified. Hypocapnic alkalosis is related to disease severity and hyperdynamic systemic circulation in patients with cirrhosis. The metabolic compensation includes alterations in serum albumin and water retention that may result in a delicate acid-base balance in these patients.

Low-frequency oscillation amplitude elevation of prefrontal cerebral hemodynamics with driving duration during prolonged driving test

NASA Astrophysics Data System (ADS)

Deng, Zishan; Gao, Yuan; Li, Ting

2018-02-01

It has been observed that there is a low-frequency oscillation (LFO) around 0.1 Hz in cerebral hemodynamics related to brain activity. Since functional near-infrared spectroscopy (fNIRS) is a novel technique to monitor hemodynamic responses noninvasively, we applied it to detect LFOs of cerebral hemodynamic parameters, such as oxyhemoglobin and deoxyhemoglobin, during prolonged driving. We performed an experiment lasting for 7 hours and an experimental test was done every hour and 8 times altogether. 7 subjects were recruited and the data of 3 of them were analyzed. By means of Fourier transformation, the amplitude of the three parameters during each test at 0.1 Hz in frequency domain was extracted. The results showed an increasing trend in the 0.1 Hz amplitudes of the three hemodynamic parameters during 7 hours' simulated driving test. Our findings indicated the potential of LFOs of prefrontal cerebral hemodynamics in brain research and brain function evaluation.

Urocortin Treatment Improves Acute Hemodynamic Instability and Reduces Myocardial Damage in Post-Cardiac Arrest Myocardial Dysfunction

PubMed Central

Huang, Chien-Hua; Wang, Chih-Hung; Tsai, Min-Shan; Hsu, Nai-Tan; Chiang, Chih-Yen; Wang, Tzung-Dau; Chang, Wei-Tien; Chen, Huei-Wen; Chen, Wen-Jone

2016-01-01

Aims Hemodynamic instability occurs following cardiac arrest and is associated with high mortality during the post-cardiac period. Urocortin is a novel peptide and a member of the corticotrophin-releasing factor family. Urocortin has the potential to improve acute cardiac dysfunction, as well as to reduce the myocardial damage sustained after ischemia reperfusion injury. The effects of urocortin in post-cardiac arrest myocardial dysfunction remain unclear. Methods and Results We developed a preclinical cardiac arrest model and investigated the effects of urocortin. After cardiac arrest induced by 6.5 min asphyxia, male Wistar rats were resuscitated and randomized to either the urocortin treatment group or the control group. Urocortin (10 μg/kg) was administrated intravenously upon onset of resuscitation in the experimental group. The rate of return of spontaneous circulation (ROSC) was similar between the urocortin group (76%) and the control group (72%) after resuscitation. The left ventricular systolic (dP/dt40) and diastolic (maximal negative dP/dt) functions, and cardiac output, were ameliorated within 4 h after ROSC in the urocortin-treated group compared to the control group (P<0.01). The neurological function of surviving animals was better at 6 h after ROSC in the urocortin-treated group (p = 0.023). The 72-h survival rate was greater in the urocortin-treated group compared to the control group (p = 0.044 by log-rank test). Cardiomyocyte apoptosis was lower in the urocortin-treated group (39.9±8.6 vs. 17.5±4.6% of TUNEL positive nuclei, P<0.05) with significantly increased Akt, ERK and STAT-3 activation and phosphorylation in the myocardium (P<0.05). Conclusions Urocortin treatment can improve acute hemodynamic instability as well as reducing myocardial damage in post-cardiac arrest myocardial dysfunction. PMID:27832152

Subendocardial viability ratio in patients with rheumatoid arthritis: comparison with healthy controls and identification of prognostic factors.

PubMed

Anyfanti, Panagiota; Triantafyllou, Areti; Gkaliagkousi, Eugenia; Triantafyllou, Georgios; Koletsos, Nikolaos; Chatzimichailidou, Sophia; Panagopoulos, Panagiotis; Botis, Ioannis; Aslanidis, Spyros; Douma, Stella

2017-06-01

Cardiac involvement is common in rheumatoid arthritis. Subendocardial viability ratio (SEVR) is a non-invasive measure of microvascular coronary perfusion, yet it remains unclear whether it is affected in rheumatoid arthritis patients. We additionally sought predictors of SEVR in rheumatoid arthritis among a wide range of disease-related parameters, cardiac and hemodynamic factors, and markers of atherosclerosis, arteriosclerosis, and endothelial dysfunction. SEVR was estimated in rheumatoid arthritis patients and healthy controls by applanation tonometry, which was also used to evaluate arterial stiffness (pulse wave velocity and augmentation index). In the rheumatoid arthritis group, carotid intima-media thickness (cIMT) was additionally estimated by ultrasound, cardiac and hemodynamic parameters by impedance cardiography, and endothelial dysfunction by measurement of asymmetric dimethylarginine (ADMA). In a total of 122 participants, SEVR was lower among 91 patients with rheumatoid arthritis compared to 31 controls (141.4 ± 21.9 vs 153.1 ± 18.7%, p = 0.009) and remained so among 29 rheumatoid arthritis patients without hypertension, diabetes, or cardiovascular diseases, compared to the control group (139.7 ± 21.7 vs 153.1 ± 18.7%, p = 0.013). SEVR did not significantly correlate with arterial stiffness, cIMT, ADMA, or disease-related parameters. Multivariate analysis revealed gender (p = 0.007), blood pressure (p = 0.028), heart rate (p = 0.025), cholesterol levels (p = 0.008), cardiac index (p < 0.001) and left ventricular ejection time (p = 0.004) as independent predictors of SEVR among patients with rheumatoid arthritis. Patients with rheumatoid arthritis exhibit lower values of SEVR compared to healthy individuals. Cardiac and hemodynamic parameters, rather than functional indices of endothelial and macrovascular dysfunction, may be useful as predictors of myocardial perfusion in rheumatoid arthritis.

The Missing Link in the Pathophysiology of Vascular Cognitive Impairment: Design of the Heart-Brain Study

PubMed Central

Hooghiemstra, Astrid M.; Bertens, Anne Suzanne; Leeuwis, Anna E.; Bron, Esther E.; Bots, Michiel L.; Brunner-La Rocca, Hans-Peter; de Craen, Anton J.M.; van der Geest, Rob J.; Greving, Jacoba P.; Kappelle, L. Jaap; Niessen, Wiro J.; van Oostenbrugge, Robert J.; van Osch, Matthias J.P.; de Roos, Albert; van Rossum, Albert C.; Biessels, Geert Jan; van Buchem, Mark A.; Daemen, Mat J.A.P.; van der Flier, Wiesje M.

2017-01-01

Background Hemodynamic balance in the heart-brain axis is increasingly recognized as a crucial factor in maintaining functional and structural integrity of the brain and thereby cognitive functioning. Patients with heart failure (HF), carotid occlusive disease (COD), and vascular cognitive impairment (VCI) present themselves with complaints attributed to specific parts of the heart-brain axis, but hemodynamic changes often go beyond the part of the axis for which they primarily seek medical advice. The Heart-Brain Study hypothesizes that the hemodynamic status of the heart and the brain is an important but underestimated cause of VCI. We investigate this by studying to what extent hemodynamic changes contribute to VCI and what the mechanisms involved are. Here, we provide an overview of the design and protocol. Methods The Heart-Brain Study is a multicenter cohort study with a follow-up measurement after 2 years among 645 participants (175 VCI, 175 COD, 175 HF, and 120 controls). Enrollment criteria are the following: 1 of the 3 diseases diagnosed according to current guidelines, age ≥50 years, no magnetic resonance contraindications, ability to undergo cognitive testing, and independence in daily life. A core clinical dataset is collected including sociodemographic factors, cardiovascular risk factors, detailed neurologic, cardiac, and medical history, medication, and a physical examination. In addition, we perform standardized neuropsychological testing, cardiac, vascular and brain MRI, and blood sampling. In subsets of participants we assess Alz­heimer biomarkers in cerebrospinal fluid, and assess echocardiography and 24-hour blood pressure monitoring. Follow-up measurements after 2 years include neuropsychological testing, brain MRI, and blood samples for all participants. We use centralized state-of-the-art storage platforms for clinical and imaging data. Imaging data are processed centrally with automated standardized pipelines. Results and Conclusions The Heart-Brain Study investigates relationships between (cardio-)vascular factors, the hemodynamic status of the heart and the brain, and cognitive impairment. By studying the complete heart-brain axis in patient groups that represent components of this axis, we have the opportunity to assess a combination of clinical and subclinical manifestations of disorders of the heart, vascular system and brain, with hemodynamic status as a possible binding factor. PMID:29017156

Dissociable Roles of Right Inferior Frontal Cortex and Anterior Insula in Inhibitory Control: Evidence from Intrinsic and Task-Related Functional Parcellation, Connectivity, and Response Profile Analyses across Multiple Datasets

PubMed Central

Ryali, Srikanth; Chen, Tianwen; Li, Chiang-Shan R.

2014-01-01

The right inferior frontal cortex (rIFC) and the right anterior insula (rAI) have been implicated consistently in inhibitory control, but their differential roles are poorly understood. Here we use multiple quantitative techniques to dissociate the functional organization and roles of the rAI and rIFC. We first conducted a meta-analysis of 70 published inhibitory control studies to generate a commonly activated right fronto-opercular cortex volume of interest (VOI). We then segmented this VOI using two types of features: (1) intrinsic brain activity; and (2) stop-signal task-evoked hemodynamic response profiles. In both cases, segmentation algorithms identified two stable and distinct clusters encompassing the rAI and rIFC. The rAI and rIFC clusters exhibited several distinct functional characteristics. First, the rAI showed stronger intrinsic and task-evoked functional connectivity with the anterior cingulate cortex, whereas the rIFC had stronger intrinsic and task-evoked functional connectivity with dorsomedial prefrontal and lateral fronto-parietal cortices. Second, the rAI showed greater activation than the rIFC during Unsuccessful, but not Successful, Stop trials, and multivoxel response profiles in the rAI, but not the rIFC, accurately differentiated between Successful and Unsuccessful Stop trials. Third, activation in the rIFC, but not rAI, predicted individual differences in inhibitory control abilities. Crucially, these findings were replicated in two independent cohorts of human participants. Together, our findings provide novel quantitative evidence for the dissociable roles of the rAI and rIFC in inhibitory control. We suggest that the rAI is particularly important for detecting behaviorally salient events, whereas the rIFC is more involved in implementing inhibitory control. PMID:25355218

Obesity and hypertensive heart disease: focus on body composition and sex differences.

PubMed

de Simone, Giovanni; Mancusi, Costantino; Izzo, Raffaele; Losi, Maria Angela; Aldo Ferrara, L

2016-01-01

There is evidence that hypertension is frequently associated with overweight/obesity even in kids and adolescents. Either conditions influence development of left ventricular (LV) hypertrophy (LVH), through different biological and hemodynamic mechanisms: obesity is conventionally thought to elicit a coherent growth of LV chamber dimensions and myocardial wall thickness (eccentric LV geometry), whereas a more accentuated increase in wall-thickness (concentric LV geometry) is attributed to hypertension. While during youth these differences are visible, proportion of LV concentric geometry, the most harmful LV geometric pattern, sharply raises in obese individuals during middle age, and becomes the most frequent geometric patterns among obese-hypertensive individuals. Two conditions with elevated hemodynamic impact, severe obstructive sleep apnea and masked hypertension contribute to the development of such a geometric pattern, but non-hemodynamic factors, and specifically body composition, also influence prevalence of concentric LV geometry. Contrasting a general belief, it has been observed that adipose mass strongly influences LV mass, particularly in women, especially when fat-free mass is relatively deficient. Thus, though blood pressure control is mandatory for prevention and reduction of LVH in obese hypertensive patients, without reduction of visceral adiposity regression of LVH is difficult. Future researches should be addressed on (1) assessing whether LVH resulting from alteration of body composition carries the same prognosis as pressure overload LVH; (2) defining tissue characterization of the hypertrophic heart in obese-hypertensive patients; (3) evaluating whether assessment of hemodynamic loading conditions and biological markers can help defining management of the association of obesity with hypertension.

Propofol or Thiopental sodium in patients undergoing reproductive assisted technologies: Differences in hemodynamic recovery and outcome of oocyte retrieval: A randomized clinical trial.

PubMed

Jarahzadeh, Mohammad Hossein; Jouya, Reza; Mousavi, Fatemeh Sadat; Dehghan-Tezerjani, Mohammad; Behdad, Shekoofa; Soltani, Hamid Reza

2014-01-01

Thiopental sodium and Propofol are two widely-used drugs in the induction of anesthesia in assisted reproductive technology (ART). However, the side effects and outcome of recovery from anesthesia of these drugs on ART have not been identified yet. This study aimed at investigating the side effects and hemodynamic effects of using thiopental sodium and propofal as well as effects of these drugs on pregnancy outcome in ART cycles. In this double blinded) randomized controlled trial, 90 woman candidate for ART were randomly divided into two groups. 47 patients received Propofol (2.5 mg/kg) and 43 patients received thiopental (5mg/kg) for anesthesia induction. The entry hemodynamic parameters of the patients were documented. During the anesthesia process, hemodynamic parameters were checked at five-minute intervals. The results of the study showed a statistically significant difference between two groups in terms of their response to verbal stimulation (p<0.001), the normalization time of the rate and quality of breathing (p<0.001), nausea (p<0.001), and vomiting (p<0.001). Also, in comparison with the other group, all these parameters were better in Propofol group. There was found no significant difference between two groups in terms of other variables. Based on the findings of the study, Propofol has fewer known side effects. Vomiting and nausea as two known side effect of anesthesia are significantly lower in patients receiving Propofol than patients who received thiopental. IRCT201303135393N2 This article extracted from M.D. thesis. (Reza Jouya).

Cerebral watershed infarcts may be induced by hemodynamic changes in blood flow.

PubMed

Shi, Jingfei; Meng, Ran; Konakondla, Sanjay; Ding, Yuchuan; Duan, Yunxia; Wu, Di; Wang, Bincheng; Luo, Yinghao; Ji, Xunming

2017-06-01

A watershed infarct is defined as an ischemic lesion at the border zones between territories of two major arteries. The pathogenesis of watershed infarcts, specifically whether they are caused by hemodynamic or embolic mechanisms, has long been debated. In this study, we aimed to examine whether watershed infarcts can be induced by altering the hemodynamic conditions in rats. In phase one, to determine the proper clamping duration for a reproducible infarct, 30 rats were equally divided into 5 subgroups and underwent bilateral common carotid artery (CCA) clamping for different durations (0.5, 1.0, 1.5, 2.0, and 3.0 hours). In phase two, to analyze the types of infarcts induced by bilateral CCA clamping, 40 rats were subjected to bilateral CCA clamping for 2 hours. As a control, 8 rats underwent all the operation procedures except bilateral CCA clamping. We performed 7.0T magnetic resonance imaging on the surviving rats on the second day to evaluate the extent of the infarcts. We further identified and examined the infarcts with brain slices stained using 2, 3, 5-triphenyltetrazolium chloride (TTC) on the third day. After 2 hours of bilateral CCA clamping, cerebral infarction occurred in 42% of surviving rats (13/31). The majority of the ischemic lesions were located in watershed regions of the brain, demonstrated by both MRI and TTC staining. Watershed infarcts were induced through changing hemodynamic conditions by bilateral CCA clamping in rats. This method may lead to the development of a reliable rodent model for watershed infarcts.

The effects of L-arginine on cerebral hemodynamics after controlled cortical impact injury in the mouse.

PubMed

Liu, Hao; Goodman, J Clay; Robertson, Claudia S

2002-03-01

Traumatic brain injury (TBI) induces vascular changes that may influence neurological outcome by causing the brain to be more susceptible to secondary ischemic insults. In rat models of TBI, L-arginine administration has been shown to restore cerebral blood flow and improve neurological outcome. The purpose of this study was to determine if hypoperfusion occurs in a mouse model of TBI and if L-arginine administration has the same beneficial effects after injury in the mouse. C57BL6 mice were anesthetized with isoflurane, intubated and mechanically ventilated, and underwent a 3-m/sec, 1.5-mm deformation cortical impact injury. Five minutes after injury, L-arginine, 300 mg/kg, or saline were administered. Arterial blood pressure, intracranial pressure, and laser Doppler flow at the impact site were monitored for 3 h after the injury. The cerebral hemodynamic effects of the TBI induced by cortical impact injury were similar to that previously observed in rats. Intracranial hypertension, with ICP peaking at 46+/-2 mm Hg, and systemic hypotension both contributed to a reduction in CPP. In addition, LDF decreased significantly at the impact site. L-Arginine administration restored LDF to near baseline levels without increasing ICP. These studies demonstrate that cerebral hemodynamics can be measured in mouse models of TBI. The changes in cerebral hemodynamics are relatively simlar to those see in the rat model of cortical impact injury and suggest an important role for nitric oxide metabolism in the maintenance of cerebral blood flow following TBI.

Laparoscopic cholecystectomy using abdominal wall retraction. Hemodynamics and gas exchange, a comparison with conventional pneumoperitoneum.

PubMed

Meijer, D W; Rademaker, B P; Schlooz, S; Bemelman, W A; de Wit, L T; Bannenberg, J J; Stijnen, T; Gouma, D F

1997-06-01

Disadvantages related to CO2 pneumoperitoneum have led to development of the abdominal wall retractor (AWR), a device designed to facilitate laparoscopic surgery without conventional pneumoperitoneum (15 mmHg CO2). We investigated the effects of the AWR on hemodynamics and gas exchange in humans. We also investigated whether the use of an AWR imposed extra technical difficulties for the surgeon. A pilot study revealed that cholecystectomy without low-pressure pneumoperitoneum was technically impossible. A prospective randomized controlled trial: Twenty patients undergoing laparoscopic cholecystectomy were randomly allocated into group 1: AWR with low-pressure pneumoperitoneum (5 mmHg), or group 2: conventional pneumoperitoneum (15 mmHg). Surgery using the AWR lasted longer, 72 +/- 16 min (mean +/- SD) vs 50 +/- 18 min compared with standard laparoscopic cholecystectomy. There were no differences between the groups with respect to hemodynamic parameters, although a small reduction of the cardiac output was observed using conventional pneumoperitoneum (from 3.9 +/- 0.7 to 3. 2 +/- 1.1 l/min) and an increase during AWR (from 4.2 +/- 0.9 to 5.2 +/- 1.5 l/min). Peak inspiratory pressures were significantly higher during conventional pneumoperitoneum compared to AWR. A slight decrease in pH accompanied by an increase in CO2 developed during pneumoperitoneum and during the use of the AWR. In both groups arterial PO2 decreased. The results indicate that the view was impaired during use of the AWR and therefore its use was difficult and time-consuming. Possible advantages of this devices' effects on hemodynamics and ventilatory parameters could not be confirmed in this study.

Evoked Electrical and Cerebral Vascular Responses Following Sleep Deprivation

PubMed Central

Schei, Jennifer L.; Rector, David M.

2011-01-01

Neuronal activity elicits vascular dilation, delivering additional blood and metabolites to the activated region. With increasing neural activity, vessels stretch and may become less compliant. Most functional imaging studies assume that limits to vascular expansion are not normally reached except under pathological conditions, with the possibility that metabolism could outpace supply. However, we previously demonstrated that evoked hemodynamic responses were larger during quiet sleep when compared to both waking and REM sleep, suggesting that high basal activity during wake may elicit blunted evoked hemodynamic responses due to vascular expansion limits. We hypothesized that extended brain activity through sleep deprivation will further dilate blood vessels, and exacerbate the blunted evoked hemodynamic responses observed during wake, and dampen responses in subsequent sleep. We measured evoked electrical and hemodynamic responses from rats using auditory clicks (0.5 s, 10 Hz, 2–13 s random ISIs) for one hour following 2, 4, or 6 hours of sleep deprivation. Time-of-day matched controls were recorded continuously for 7 hours. Within quiet sleep periods following deprivation, ERP amplitude did not differ; however, the evoked vascular response was smaller with longer sleep deprivation periods. These results suggest that prolonged neural activity periods through sleep deprivation may diminish vascular compliance as indicated by the blunted vascular response. Subsequent sleep may allow vessels to relax, restoring their ability to deliver blood. These results also suggest that severe sleep deprivation or chronic sleep disturbances could push the vasculature to critical limits, leading to metabolic deficit and the potential for tissue trauma. PMID:21854966

PM101: a cyclodextrin-based intravenous formulation of amiodarone devoid of adverse hemodynamic effects.

PubMed

Cushing, Daniel J; Kowey, Peter R; Cooper, Warren D; Massey, Bill W; Gralinski, Michael R; Lipicky, Raymond J

2009-04-01

Intravenous amiodarone (Amiodarone i.v.) is widely used to treat cardiac arrhythmias. The most frequent clinical adverse event associated with Amiodarone i.v. administration is systemic hypotension which has been attributed to the cosolvents used in the formulation, polysorbate 80 and benzyl alcohol. To minimize hypotension Amiodarone i.v. is diluted in 5% dextrose in water prior to administration and slowly infused. PM101 is a novel intravenous formulation that uses sulfobutylether-7-beta-cyclodextrin to solubilize amiodarone, and thus should be devoid of the untoward hemodynamic effects associated with polysorbate 80 and benzyl alcohol. Beagle dogs (n=7/group) were anesthetized with morphine and alpha-chloralose and instrumented to assess aortic blood pressure, cardiac output, cardiac contractility, and heart rate. Animals were treated with the U.S. approved human-equivalent loading dose (2.14 mg/kg) of Amiodarone i.v., PM101, and their respective vehicle controls. Administration of Amiodarone i.v. rapidly and significantly decreased mean aortic pressure, cardiac output, and cardiac contractility. A significant increase in heart rate was also observed as was a transient, but not significant, decrease in systemic vascular resistance. A similar pattern of rapid and significant hemodynamic changes was produced by the Amiodarone i.v. Vehicle (polysorbate 80/benzyl alcohol) alone. In marked contrast, PM101 and its vehicle produced no significant hemodynamic effects. This study provides a useful model for the continued search for a safe and effective intravenous amiodarone formulation devoid of the hypotensive risk associated with the current commercial formulation.

Non-invasive assessment of cerebral microcirculation with diffuse optics and coherent hemodynamics spectroscopy

NASA Astrophysics Data System (ADS)

Fantini, Sergio; Sassaroli, Angelo; Kainerstorfer, Jana M.; Tgavalekos, Kristen T.; Zang, Xuan

2016-03-01

We describe the general principles and initial results of coherent hemodynamics spectroscopy (CHS), which is a new technique for the quantitative assessment of cerebral hemodynamics on the basis of dynamic near-infrared spectroscopy (NIRS) measurements. The two components of CHS are (1) dynamic measurements of coherent cerebral hemodynamics in the form of oscillations at multiple frequencies (frequency domain) or temporal transients (time domain), and (2) their quantitative analysis with a dynamic mathematical model that relates the concentration and oxygen saturation of hemoglobin in tissue to cerebral blood volume (CBV), cerebral blood flow (CBF), and cerebral metabolic rate of oxygen (CMRO2). In particular, CHS can provide absolute measurements and dynamic monitoring of CBF, and quantitative measures of cerebral autoregulation. We report initial results of CBF measurements in hemodialysis patients, where we found a lower CBF (54 +/- 16 ml/(100 g-min)) compared to a group of healthy controls (95 +/- 11 ml/(100 g-min)). We also report CHS measurements of cerebral autoregulation, where a quantitative index of autoregulation (its cutoff frequency) was found to be significantly greater in healthy subjects during hyperventilation (0.034 +/- 0.005 Hz) than during normal breathing (0.017 +/- 0.002 Hz). We also present our approach to depth resolved CHS, based on multi-distance, frequency-domain NIRS data and a two-layer diffusion model, to enhance sensitivity to cerebral tissue. CHS offers a potentially powerful approach to the quantitative assessment and continuous monitoring of local brain perfusion at the microcirculation level, with prospective brain mapping capabilities of research and clinical significance.

Body position does not affect the hemodynamic response to venous air embolism in dogs

NASA Technical Reports Server (NTRS)

Mehlhorn, U.; Burke, E. J.; Butler, B. D.; Davis, K. L.; Katz, J.; Melamed, E.; Morris, W. P.; Allen, S. J.

1994-01-01

Current therapy for massive venous air embolism (VAE) includes the use of the left lateral recumbent (LLR) position. This recommendation is based on animal studies, conducted 50 yr ago, which looked primarily at survival. Little is known, however, about the concomitant hemodynamic response after VAE in various body positions. The purpose of this study was to investigate the hemodynamic and cardiovascular changes in various body positions after VAE. Twenty-two mechanically ventilated supine mongrel dogs received a venous air infusion of 2.5 mL/kg at a rate of 5 mL/s. One minute after the infusion, 100% oxygen ventilation was commenced and the body position of the dogs was changed to either the LLR (n = 6), the LLR with the head 10 degrees down (LLR-10 degrees; n = 6) or the right lateral recumbent (RLR; n = 5) position. Five dogs were maintained in the supine position (SUP; n = 5). One dog died in every group except in the SUP group, where all the dogs recovered. There were no significant differences among the various body positions in terms of heart rate, mean arterial pressure, pulmonary artery pressure, central venous pressure, left ventricular end-diastolic pressure, or cardiac output. The acute hemodynamic changes occurring during the first 5-15 min after VAE recovered to 80% of control within 60 min. Our data suggest that body repositioning does not influence the cardiovascular response to VAE. Specifically, our data do not support the recommendation of repositioning into the LLR position for the treatment of VAE.

Body position does not affect the hemodynamic response to venous air embolism in dogs

NASA Technical Reports Server (NTRS)

Mehlhorn, Uwe; Burke, Edward J.; Butler, Bruce D.; Davis, Karen L.; Katz, Jeffrey; Melamed, Evan; Morris, William P.; Allen, Steven J.

1993-01-01

Current therapy for massive venous air embolism (VAE) includes the use of the left lateral recumbent (LLR) position. This recommendation is based on animal studies, conducted 50 years ago, which looked primarily at survival. Little is known, however, about the concomitant hemodynamic response after VAE in various body positions. The purpose of this study was to investigate the hemodynamic and cardiovascular changes in various body positions after VAE. Twenty-two mechanically ventilated supine mongrel dogs received a venous air infusion of 2.5 mL/kg at a rate of 5 mL/s. One minute after the infusion, 100% oxygen ventilation was commenced and the body position of the dogs was changed to either the LLR (n = 6), the LLR with the head 10 deg down (LLR-10 deg; n = 6) or the right lateral recumbent (RLR; n = 5) position. Five dogs were maintained in the supine position (SUP; n = 5). One dog died in every group except in the SUP group, where all the dogs recovered. There were no significant differences among the various body positions in terms of heart rate, mean arterial pressure, pulmonary artery pressure, central venous pressure, left ventricular end-diastolic pressure, or cardiac output. The acute hemodynamic changes occurring during the first 5-15 min after VAE recovered to 80% of control within 60 min. Our data suggest that body repositioning does not influence the cardiovascular response to VAE. Specifically, our data do not support the recommendation of repositioning into the LLR position for the treatment of VAE.

Hemodynamic effects of calcium antagonists in cardiac patients.

PubMed

Pozenel, H

1982-01-01

Hemodynamic studies were carried out after cardiac catheterization with a floatation catheter in the pulmonary artery and cannulation of the brachial artery for the calculation of cardiac output by means of the Fick principle. Continuous pressure recordings were carried out at rest and under submaximal treadmill exercise in the supine body position in 5 homogeneous groups of 12 patients, all with disorders due to coronary disease. In a control test, hemodynamic investigations were carried out at rest before medication, under stress and after recovery. Similar tests were performed after intravenous administration of either isotonic saline as placebo, tiapamil (1.1 and 1.6 mg/kg) or verapamil (0.07 and 0.14 mg/kg). It was shown that there was a marked dose-related reduction in peripheral vascular resistance with a maximum effect occurring at 2-5 min after the intravenous administration of tiapamil (1.1 and 1.6 mg/kg) reaching 23 and 39%, respectively, or verapamil (0.07 and 0.14 mg/kg) attaining 28 and 39%, respectively, at rest and, to a similar extent, under stress conditions. In patients with sinus rhythm, the mean arterial pressure was reduced. Cardiac outputs and stroke volumes were increased at rest as well as under stress. There was no evidence of a depressant action of the drug on hemodynamic variables. An interplay of simultaneous changes in preload and afterload seems to be responsible for the effects obtained. The doses used were those commonly employed in the termination of supraventricular tachyarrhythmias. However, a potential depressant effect of tiapamil in patients with markedly reduced ventricular function is not excluded by this study.

Evidence Underpinning the Centers for Medicare & Medicaid Services' Severe Sepsis and Septic Shock Management Bundle (SEP-1): A Systematic Review.

PubMed

Pepper, Dominique J; Jaswal, Dharmvir; Sun, Junfeng; Welsh, Judith; Natanson, Charles; Eichacker, Peter Q

2018-04-17

This article has been corrected. To see what has changed, please read the Letter to the Editor and the authors' response. The original version (PDF) is appended to this article as a Supplement. The Severe Sepsis and Septic Shock Early Management Bundle (SEP-1), the sepsis performance measure introduced in 2015 by the Centers for Medicare & Medicaid Services (CMS), requires the reporting of up to 5 hemodynamic interventions, as many as 141 tasks, and 3 hours to document for a single patient. To evaluate whether moderate- or high-level evidence shows that use of the 2015 SEP-1 or its hemodynamic interventions improves survival in adults with sepsis. PubMed, Embase, Scopus, Web of Science, and ClinicalTrials.gov from inception to 28 November 2017 with no language restrictions. Randomized and observational studies of death among adults with sepsis who received versus those who did not receive either the entire SEP-1 bundle or 1 or more SEP-1 hemodynamic interventions, including serial lactate measurements; a fluid infusion of 30 mL/kg of body weight; and assessment of volume status and tissue perfusion with a focused examination, bedside cardiovascular ultrasonography, or fluid responsiveness testing. Two investigators independently extracted study data and assessed each study's risk of bias; 4 authors rated level of evidence by consensus using CMS criteria published in 2013. High- or moderate-level evidence required studies to have no confounders and low risk of bias. Of 56 563 references, 20 studies (18 reports) met inclusion criteria. One single-center observational study reported lower in-hospital mortality after implementation of the SEP-1 bundle. Sixteen studies (2 randomized and 14 observational) reported increased survival with serial lactate measurements or 30-mL/kg fluid infusions. None of the 17 studies were free of confounders or at low risk of bias. In 3 randomized trials, fluid responsiveness testing did not alter survival. Few trials, poor-quality and confounded studies, and no studies (with survival outcomes) of the focused examination or bedside cardiovascular ultrasonography. Use of the 2015 version of SEP-1 and 2013 version of CMS evidence criteria, both of which were updated in 2017. No high- or moderate-level evidence shows that SEP-1 or its hemodynamic interventions improve survival in adults with sepsis. National Institutes of Health. (PROSPERO: CRD42016052716).

[Automatic system control and its application in dialysis].

PubMed

Santoro, A; Mancini, E; Ferramosca, E

2007-01-01

The progressive increase in the mean age of dialysis patients associated with increasing comorbidity factors such as the presence of cardiovascular disease and diabetes have significantly worsened patients' clinical status and tolerance to hemodialysis. On the other hand, the demand for short treatment times increases the risk of hemodynamic instability as well as inadequate depuration. The traditional management of the dialysis session by setting predefined treatment parameters and carrying out active therapeutic intervention only in the event of complications is definitely unsuitable for short-lasting treatments, which are often complicated by hemodynamic instability, especially in critically ill patients. The first step in improving the management of the dialysis session is the use of uninvasive systems for continuous monitoring of the hemodynamic and biochemical parameters that characterize dialysis quality. In the last decade, special sensors have been designed for continuous measurement of blood volume, blood temperature, blood pressure, heart rate and electrolytes. As a second step, some of these devices have been interfaced with the dialysis equipment, mainly with a view to preventing cardiocirculatory instability but also monitoring the efficiency of dialysis (biofeedback control systems). The basic components of a biofeedback system are the plant, the sensors, the actuators, and the controller. The plant is the biological process we need to control, while the sensors are the devices used for measuring the output variables. The actuators are the working arms of the controller. The controller is the mathematical model that continuously sets the measured output variable against the reference input and modifies the actuators in order to reduce any discrepancies. In actual practice, however, there are a number of conceptual, physical and technological difficulties to overcome. In particular, the behavior of what is to be controlled may be nonlinear and time-varying, with interactions between the actuators and the controlled variable. In such cases, more sophisticated control systems are needed that must be capable of identifying the behavior of the process and continuously update information data while the control is on. These complex systems are called adaptive controllers. At present, there are three biofeedback systems routinely used in clinical dialysis. All of them are aimed at improving the cardiovascular stability during hemodialysis, which at present is one of the main problems limiting the tolerance to treatment on the one hand and the quality of hemodialysis on the other. These systems include biofeedback control of blood volume, biofeedback control of thermal balance, and biofeedback control of blood pressure.

Biofeedback-driven dialysis: where are we?

PubMed

Santoro, Antonio; Ferramosca, Emiliana; Mancini, Elena

2008-01-01

The progressive increase in the mean age and the growing conditions of co-morbidity, especially of cardiovascular pathologies and diabetes, have significantly worsened the patients' clinical status and tolerance to the hemodialysis (HD) treatment. On the other hand, the demand for short treatment times enhances the risk for hemodynamic instability as well as for inadequate depuration. The traditional management of the dialysis session, setting of predefined treatment parameters, with active therapeutic interventions only in the event of complications, is definitely unsuitable for short-lasting treatments, often complicated by hemodynamic instability, especially in critical patients. The first step to improve the management of the dialysis session is the utilization of continuous and uninvasive monitoring systems for hemodynamic or biochemical parameters involved in the dialysis quality. Special sensors for the continuous measurement of blood volume, blood temperature, blood pressure, heart rate, electrolytes, have been realized throughout the last 10 years. As a second step, some of these devices have been implemented in the dialysis instrumentation, mainly with a view to preventing cardiocirculatory instability but also to control the dialysis efficiency (biofeedback control systems). The basic components of a biofeedback system are: the plant, the sensors, the actuators and the controller. The plant is the biological process that we need to control, while the sensors are the devices used for measuring the output variables. The actuators are the working arms of the controller. The controller is the mathematical model that continuously sets the measured output variable against the reference input and modifies the actuators in order to reduce any discrepancies. Yet, in practice there are a number of conceptual, physical and technological difficulties to be overcome. In particular, the behavior of what is to be controlled may be non-linear and time-varying, with interactions between the actuators and the controlled variable. In these cases, more sophisticated control systems are needed, which must be capable of identifying the behavior of the process, and continuously update information data while the control is on. These complex systems are called adaptive controllers. In dialysis, over the last few years, it has been relatively easy to realize some biofeedback systems since a series of sensors have been developed for online monitoring. Three biofeedback devices are routinely used with the aim of improving the cardiovascular instability, one of the main problems limiting the tolerance to treatment by the patient and the quality of HD in itself - the first is the biofeedback control of blood volume, the second is the biofeedback control of thermal balance, and the third is the biofeedback control of blood pressure.

[Experimental study of acute brain swelling under acute intracranial hypertension (author's transl)].

PubMed

Shigemori, M; Watanabe, M; Kuramoto, S

1976-12-01

There are many problems about the cause, pathophysiology and treatment of acute brain swelling under intracranial hypertension frequently encountered in the neurosurgical clinics. Generally, rapid increase of the cerebral vasoparesis caused by unknown etiology is thought to be the main cause of acute brain swelling under intracranial hypertension. Moreover, disturbance of the cerebral venous circulatory system is discussed recently by many authors. But, research from the point of systemic respiration and hemodynamics is necessary for resolving these problems. This experiment was designed to study the effects of respiration and hemodynamics on the cerebral vasoparesis. Using 22 adult dogs, acute intracranial hypertension was produced by epidural balloon inflation sustained at the level of 300 - 400 mmH2O. Simultaneously with measurement of intracranial pressure at the epidural space, superior sagittal sinus pressure, respirogram, systemic blood pressure (femoral artery), central venous pressure, common carotid blood flow, EKG and bipolar lead EEG were monitored continuously. The experimental group was divided by the respiratory loading into 5 groups as follows: control (6 cases), 10% CO2 hypercapnia (4 cases), 10% O2 hypoxia (4 cases), stenosis of airway (5 cases), 100% O2-controled respiration (3 cases). 1) Cerebral vasoparesis under acute intracranial hypertension took place earlier and showed more rapid progression in groups of stenosis of airway, hypercapnia and hypoxia than control group of spontaneous respiration in room air. No occurrence of cerebral vasoparesis was found out in a group of 100% O2 controlled respiration. It is proved that increased airway resistance or asphyxia, hypercapnia and hypoxia have strictly reference to the occurrence and progression of cerebral vasoparesis and for the prevention of cerebral vasoparesis, correct 100% O2 cont rolled respiration is effective. 2) From the hemodynamic change, the progression of rapid increase of cerebral blood volume with increase of blood volume in the superior sagitta sinus during cerebral vasoparesis under intracranial hypertension is presumed. It is suggested from the superior sagittal sinus pressure in various experimental groups that the site, reactivity and disturbed degree of the cerebral venous system are changed by the difference of respiratory or ventrilatory state and the cerebral venous circulatory disturbance has also reference to the occurrence of acute brain swelling. 3) During cerebral vasopareris under acute intracranial hypertension, remarkable supression of respiration, increased central venous pressure and increased common carotid blood flow were observed. It is concluded that the reaction of systemic hemodynamics following respiratory change effects on cerebral circulation markedly and they are being important factors to occurrence of acute brain swelling.

Perfluorocarbon-associated gas exchange in normal and acid-injured large sheep.

PubMed

Hernan, L J; Fuhrman, B P; Kaiser, R E; Penfil, S; Foley, C; Papo, M C; Leach, C L

1996-03-01

We hypothesized that a) perfluorocarbon-associated gas exchange could be accomplished in normal large sheep; b) the determinants of gas exchange would be similar during perfluorocarbon-associated gas exchange and conventional gas ventilation; c)in large animals with lung injury, perfluorocarbon-associated gas exchange could be used to enhance gas exchange without adverse effects on hemodynamics; and d) the large animal with lung injury could be supported with an FIO2 of <1.0 during perfluorocarbon-associated gas exchange. Prospective, observational animal study and prospective randomized, controlled animal study. An animal laboratory in a university setting. Thirty adult ewes. Five normal ewes (61.0 +/- 4.0 kg) underwent perfluorocarbon-associated gas exchange to ascertain the effects of tidal volume, end-inspiratory pressure, and positive end-expiratory pressure (PEEP) on oxygenation. Respiratory rate, tidal volume, and minute ventilation were studied to determine their effects on CO2 clearance. Sheep, weighing 58.9 +/- 8.3 kg, had lung injury induced by instilling 2 mL/kg of 0.05 Normal hydrochloric acid into the trachea. Five minutes after injury, PEEP was increased to 10 cm H2O. Ten minutes after injury, sheep with Pao2 values of <100 torr (<13.3 kPa) were randomized to continue gas ventilation (control, n=9) or to institute perfluorocarbon-associated gas exchange (n=9) by instilling 1.6 L of unoxygenated perflubron into the trachea and resuming gas ventilation. Blood gas and hemodynamic measurements were obtained throughout the 4-hr study. Both tidal volume and end-inspiratory pressure influenced oxygenation in normal sheep during perfluorocarbon-associated gas exchange. Minute ventilation determined CO2 clearance during perfluorocarbon-associated gas exchange in normal sheep. After acid aspiration lung injury, perfluorocarbon-associated gas exchange increased PaO2 and reduced intrapulmonary shunt fraction. Hypoxia and intrapulmonary shunting were unabated after injury in control animals. Hemodynamics were not influenced by the institution of perfluorocarbon-associated gas exchange. Tidal volume and end-inspiratory pressure directly influence oxygenation during perfluorocarbon-associated gas exchange in large animals. Minute ventilation influences clearance of CO2. In adult sheep with acid aspiration lung injury, perfluorocarbon-associated gas exchange at an FIO2 of <1.0 supports oxygenation and improves intrapulmonary shunting, without adverse hemodynamic effects, when compared with conventional gas ventilation.

Pharmacokinetics of Acetaminophen in Hind Limbs Unloaded Mice: A Model System Simulating the Effects of Low Gravity on Astronauts in Space

NASA Technical Reports Server (NTRS)

Peterson, Amanda; Risin, Semyon A.; Ramesh, Govindarajan T.; Dasgupta, Amitava; Risin, Diana

2008-01-01

The pharmacokinetics (PK) of medications administered to astronauts could be altered by the conditions in Space. Low gravity and free floating (and associated hemodynamic changes) could affect the absorption, distribution, metabolism and excretion of the drugs. Knowledge of these alterations is essential for adjusting the dosage and the regimen of drug administration in astronauts. Acquiring of such knowledge has inherent difficulties due to limited opportunities for experimenting in Space. One of the approaches is to use model systems that simulate some of the Space conditions on Earth. In this study we used hind limbs unloaded mice (HLU) to investigate the possible changes in PK of acetaminophen, a widely used analgesic with high probability of use by astronauts. The HLU is recognized as an appropriate model for simulating the effects of low gravity on hemodynamic parameters. Mice were tail suspended (n = 24) for 24-96 hours prior to introduction of acetaminophen (150 - 300 mg/kg). The drug (in aqueous solution containing 10% ethyl alcohol by volume) was given orally by a gavage procedure and after the administration of acetaminophen mice were additionally suspended for 30 min, 1 and 2 hours. Control mice (n = 24) received the same dose of acetaminophen and were kept freely all the time. Blood specimens were obtained either from retroorbital venous sinuses or from heart. Acetaminophen concentration was measured in plasma by the fluorescent polarization immunoassay and the AxSYM analyzer (Abbott Laboratories). In control mice peak acetaminophen concentration was achieved at 30 min. By 1 hour the concentration decreased to less than 50% of the peak level and at 2 hours the drug was almost undetectable in the serum. HLU for 24 hours significantly altered the acetaminophen pharmacokinetic: at 30 min the acetaminophen concentrations were significantly (both statistically and medically significant) lower than in control mice. The concentrations also reduced less significantly after 1 and 2 hours. At 2 hours approximately 20% of the drug still remained in the circulation. After 96 hrs of HLU the changes in acetaminophen PK were less prominent. These data indicate that short term HLU causes significant changes in acetaminophen PK most likely associated with HUL-related hemodynamic changes. However, after 96 hour these changes diminished. This suggests hemodynamic adaptation to the HUL conditions that possibly occurs also in real space conditions.

Management of splenic and pancreatic trauma.

PubMed

Girard, E; Abba, J; Cristiano, N; Siebert, M; Barbois, S; Létoublon, C; Arvieux, C

2016-08-01

The spleen and pancreas are at risk for injury during abdominal trauma. The spleen is more commonly injured because of its fragile structure and its position immediately beneath the ribs. Injury to the more deeply placed pancreas is classically characterized by discordance between the severity of pancreatic injury and its initial clinical expression. For the patient who presents with hemorrhagic shock and ultrasound evidence of major hemoperitoneum, urgent "damage control" laparotomy is essential; if splenic injury is the cause, prompt "hemostatic" splenectomy should be performed. Direct pancreatic injury is rarely the cause of major hemorrhage unless a major neighboring vessel is injured, but if there is destruction of the pancreatic head, a two-stage pancreatoduodenectomy (PD) may be indicated. At open laparotomy when the patient's hemodynamic status can be stabilized, it may be possible to control splenic bleeding without splenectomy; it is always essential to search for injury to the pancreatic duct and/or the adjacent duodenum. Pancreatic contusion without ductal rupture is usually treated by drain placement adjacent to the injury; ductal injuries of the pancreatic body or tail are treated by resection (distal pancreatectomy with or without splenectomy), with generally benign consequences. For injuries of the pancreatic head with pancreatic duct disruption, wide drainage is usually performed because emergency PD is a complex gesture prone to poor results. Postoperatively, the placement of a ductal stent by endoscopic retrograde catheterization may be decided, while management of an isolated pancreatic fistula is often straightforward. Non-operative management is the rule for the trauma victim who is hemodynamically stable. In addition to the clinical examination and conventional laboratory tests, investigations should include an abdominothoracic CT scan with contrast injection, allowing identification of all traumatized organs and assessment of the severity of injury. In this context, non-operative management (NOM) has gradually become the standard as long as the patient remains hemodynamically stable and there is no suspicion of injury to hollow viscera, with the patient being carefully monitored on a surgical service. The development of arteriography with splenic artery embolization has increased the rate of splenic salvage; this can be performed electively based on specific indications (blush on CT, pseudoaneurysm, arteriovenous fistula), and may also be considered for severe splenic injury, abundant hemoperitoneum, or severe polytrauma. For pancreatic injury, in addition to CT scan, magnetic resonance pancreatography (MRCP) or even endoscopic retrograde cholangiopancreatography (ERCP) may be necessary to identify a ductal rupture. If the pancreatic duct is intact, laboratory and CT imaging surveillance is performed just as for splenic injury. In case of pancreatic ductal injury, ERCP stenting can be considered. However, if this is unsuccessful, the therapeutic decision can be difficult: while NOM can still be successful, complications may arise that are difficult to treat while distal pancreatectomy, although initially more agressive may avoid these complications if performed early. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Using functional hemodynamic indicators to guide fluid therapy.

PubMed

Bridges, Elizabeth

2013-05-01

Hemodynamic monitoring has traditionally relied on such static pressure measurements as pulmonary artery occlusion pressure and central venous pressure to guide fluid therapy. Over the past 15 years, however, there's been a shift toward less invasive or noninvasive monitoring methods, which use "functional" hemodynamic indicators that reflect ventilator-induced changes in preload and thereby more accurately predict fluid responsiveness. The author reviews the physiologic principles underlying functional hemodynamic indicators, describes how the indicators are calculated, and discusses when and how to use them to guide fluid resuscitation in critically ill patients.

Less invasive methods of advanced hemodynamic monitoring: principles, devices, and their role in the perioperative hemodynamic optimization

PubMed Central

2013-01-01

The monitoring of the cardiac output (CO) and other hemodynamic parameters, traditionally performed with the thermodilution method via a pulmonary artery catheter (PAC), is now increasingly done with the aid of less invasive and much easier to use devices. When used within the context of a hemodynamic optimization protocol, they can positively influence the outcome in both surgical and non-surgical patient populations. While these monitoring tools have simplified the hemodynamic calculations, they are subject to limitations and can lead to erroneous results if not used properly. In this article we will review the commercially available minimally invasive CO monitoring devices, explore their technical characteristics and describe the limitations that should be taken into consideration when clinical decisions are made. PMID:24472443

Neurovascular coupling in normal aging: a combined optical, ERP and fMRI study.

PubMed

Fabiani, Monica; Gordon, Brian A; Maclin, Edward L; Pearson, Melanie A; Brumback-Peltz, Carrie R; Low, Kathy A; McAuley, Edward; Sutton, Bradley P; Kramer, Arthur F; Gratton, Gabriele

2014-01-15

Brain aging is characterized by changes in both hemodynamic and neuronal responses, which may be influenced by the cardiorespiratory fitness of the individual. To investigate the relationship between neuronal and hemodynamic changes, we studied the brain activity elicited by visual stimulation (checkerboard reversals at different frequencies) in younger adults and in older adults varying in physical fitness. Four functional brain measures were used to compare neuronal and hemodynamic responses obtained from BA17: two reflecting neuronal activity (the event-related optical signal, EROS, and the C1 response of the ERP), and two reflecting functional hemodynamic changes (functional magnetic resonance imaging, fMRI, and near-infrared spectroscopy, NIRS). The results indicated that both younger and older adults exhibited a quadratic relationship between neuronal and hemodynamic effects, with reduced increases of the hemodynamic response at high levels of neuronal activity. Although older adults showed reduced activation, similar neurovascular coupling functions were observed in the two age groups when fMRI and deoxy-hemoglobin measures were used. However, the coupling between oxy- and deoxy-hemoglobin changes decreased with age and increased with increasing fitness. These data indicate that departures from linearity in neurovascular coupling may be present when using hemodynamic measures to study neuronal function. Copyright © 2013 Elsevier Inc. All rights reserved.

Hemodynamic stability during laryngeal electromyography procedures.

PubMed

Lu, Yi-An; Pei, Yu-Cheng; Wong, Alice Mk; Chiang, Hui-Chen; Fang, Tuan-Jen

2017-10-01

Laryngeal electromyography (LEMG) is accepted as safe, with minimal side effects. However, patient hemodynamic stability, during these procedures, has not been reported. This study aimed to investigate the hemodynamics in patients undergoing LEMG and determine the risk factors for hemodynamic changes. We recruited 89 consecutive patients who underwent LEMG. Baseline and postprocedural changes in vital signs were analyzed. Diastolic blood pressure (DBP) increased from 75.08 ± 11.54 mmHg preprocedure to 77.4 ± 11.91 mmHg postprocedure (p = .006); pulse rate (PR) increased from 78.1 ± 13.3 beats per minute preprocedure to 80.02 ± 13.69 postprocedure (p = .027). Systolic blood pressure (SBP) and oxygen saturation were unchanged after the procedure. However, about 17% of patients experienced profound changes in vital signs of >20% above baseline during LEMG. The hemodynamic changes did not differ between sexes or between surgical and non-surgical etiologies of vocal fold paralysis. Two patients experienced profound but reversible near-syncope during the procedure. LEMG is a safe procedure with few immediate complications, though it may affect the patient's hemodynamic status by increasing DBP and PR. The hemodynamic monitoring is recommended so that timely intervention can be applied in case any warning sign occurs.

Microfluidic assay of the deformability of primitive erythroblasts.

PubMed

Zhou, Sitong; Huang, Yu-Shan; Kingsley, Paul D; Cyr, Kathryn H; Palis, James; Wan, Jiandi

2017-09-01

Primitive erythroblasts (precursors of red blood cells) enter vascular circulation during the embryonic period and mature while circulating. As a result, primitive erythroblasts constantly experience significant hemodynamic shear stress. Shear-induced deformation of primitive erythroblasts however, is poorly studied. In this work, we examined the deformability of primitive erythroblasts at physiologically relevant flow conditions in microfluidic channels and identified the regulatory roles of the maturation stage of primitive erythroblasts and cytoskeletal protein 4.1 R in shear-induced cell deformation. The results showed that the maturation stage affected the deformability of primitive erythroblasts significantly and that primitive erythroblasts at later maturational stages exhibited a better deformability due to a matured cytoskeletal structure in the cell membrane.

High-Output Heart Failure Caused by Thyrotoxicosis and Beriberi.

PubMed

McCulloch, Brenda

2015-12-01

High-output heart failure is not seen as commonly as low-output heart failure and some of the typical guideline recommendations may not benefit patients with high-output failure. High-output failure is caused by several diseases, including thyrotoxicosis and beriberi, highlighted in this article. Thyrotoxicosis, caused by excessive thyroid hormone production, has profound hemodynamic effects. Wet beriberi, affecting predominately the cardiovascular system, is caused by severe thiamine deficiency, most commonly seen in patients with chronic alcoholism or poor nutrition from other causes. Prompt recognition of these infrequently seen syndromes is essential. This article outlines the medical treatment and nursing care needed to return these patients to a normal state. Copyright © 2015 Elsevier Inc. All rights reserved.

“Beyond saving lives”: Current perspectives of interventional radiology in trauma

PubMed Central

Singh, Anuradha; Kumar, Atin; Kumar, Pawan; Kumar, Subodh; Gamanagatti, Shivanand

2017-01-01

Interventional radiology (IR) has become an integral part in the management of traumatic injuries. There is an ever-increasing role of IR in traumatic injuries of solid abdominal organs, pelvic and peripheral arteries to control active bleeding by therapeutic embolization or vascular reconstruction using stent grafts. Traditionally, these endovascular treatments have been offered to hemodynamically stable patients. However, in recent times endovascular approach has become preferable to surgery even in hemodynamically unstable patients with injury of surgically difficult-to-access sites. With shifting trends towards non operative management coupled with availability of the current state-of-the-art equipments, hardware and technical expertise, IR has gained an impeccable role in trauma management. However, due to lack of awareness and widespread acceptance, IR continues to remain an ocean of unexplored potentialities. PMID:28529680

Study Design and Rationale of "A Multicenter, Open-Labeled, Randomized Controlled Trial Comparing MIdazolam Versus MOrphine in Acute Pulmonary Edema": MIMO Trial.

PubMed

Dominguez-Rodriguez, Alberto; Burillo-Putze, Guillermo; Garcia-Saiz, Maria Del Mar; Aldea-Perona, Ana; Harmand, Magali González-Colaço; Mirò, Oscar; Abreu-Gonzalez, Pedro

2017-04-01

Morphine has been used for several decades in cases of acute pulmonary edema (APE) due to the anxiolytic and vasodilatory properties of the drug. The non-specific depression of the central nervous system is probably the most significant factor for the changes in hemodynamics in APE. Retrospective studies have shown both negative and neutral effects in patients with APE and therefore some authors have suggested benzodiazepines as an alternative treatment. The use of intravenous morphine in the treatment of APE remains controversial. The MIdazolan versus MOrphine in APE trial (MIMO) is a multicenter, prospective, open-label, randomized study designed to evaluate the efficacy and safety of morphine in patients with APE. The MIMO trial will evaluate as a primary endpoint whether intravenous morphine administration improves clinical outcomes defined as in-hospital mortality. Secondary endpoint evaluation will be mechanical ventilation, cardiopulmonary resuscitation, intensive care unit admission rate, intensive care unit length of stay, and hospitalization length. In the emergency department, morphine is still used for APE in spite of poor scientific background data. The data from the MIMO trial will establish the effect-and especially the risk-when using morphine for APE.

Renal Safety Pharmacology in Drug Discovery and Development.

PubMed

Benjamin, Amanda; Nogueira da Costa, Andre; Delaunois, Annie; Rosseels, Marie-Luce; Valentin, Jean-Pierre

2015-01-01

The kidney is a complex excretory organ playing a crucial role in various physiological processes such as fluid and electrolyte balance, control of blood pressure, removal of waste products, and drug disposition. Drug-induced kidney injury (DIKI) remains a significant cause of candidate drug attrition during drug development. However, the incidence of renal toxicities in preclinical studies is low, and the mechanisms by which drugs induce kidney injury are still poorly understood. Although some in vitro investigational tools have been developed, the in vivo assessment of renal function remains the most widely used methodology to identify DIKI. Stand-alone safety pharmacology studies usually include assessment of glomerular and hemodynamic function, coupled with urine and plasma analyses. However, as renal function is not part of the ICH S7A core battery, such studies are not routinely conducted by pharmaceutical companies. The most common approach consists in integrating renal/urinary measurements in repeat-dose toxicity studies. In addition to the standard analyses and histopathological examination of kidneys, novel promising urinary biomarkers have emerged over the last decade, offering greater sensitivity and specificity than traditional renal parameters. Seven of these biomarkers have been qualified by regulatory agencies for use in rat toxicity studies.

The Renal Renin-Angiotensin System

ERIC Educational Resources Information Center

Harrison-Bernard, Lisa M.

2009-01-01

The renin-angiotensin system (RAS) is a critical regulator of sodium balance, extracellular fluid volume, vascular resistance, and, ultimately, arterial blood pressure. In the kidney, angiotensin II exerts its effects to conserve salt and water through a combination of the hemodynamic control of renal blood flow and glomerular filtration rate and…

Age and Vascular Burden Determinants of Cortical Hemodynamics Underlying Verbal Fluency.

PubMed

Heinzel, Sebastian; Metzger, Florian G; Ehlis, Ann-Christine; Korell, Robert; Alboji, Ahmed; Haeussinger, Florian B; Wurster, Isabel; Brockmann, Kathrin; Suenkel, Ulrike; Eschweiler, Gerhard W; Maetzler, Walter; Berg, Daniela; Fallgatter, Andreas J

2015-01-01

Aging processes and several vascular burden factors have been shown to increase the risk of dementia including Alzheimer's disease. While pathological alterations in dementia precede diagnosis by many years, reorganization of brain processing might temporarily delay cognitive decline. We hypothesized that in healthy elderly individuals both age-related neural and vascular factors known to be related to the development of dementia impact functional cortical hemodynamics during increased cognitive demands. Vascular burden factors and cortical functional hemodynamics during verbal fluency were assessed in 1052 non-demented elderly individuals (51 to 83 years; cross-sectional data of the longitudinal TREND study) using functional near-infrared spectroscopy (fNIRS). The prediction of functional hemodynamic responses by age in multiple regressions and the impact of single and cumulative vascular burden factors including hypertension, diabetes, obesity, smoking and atherosclerosis were investigated. Replicating and extending previous findings we could show that increasing age predicted functional hemodynamics to be increased in right prefrontal and bilateral parietal cortex, and decreased in bilateral inferior frontal junction during phonological fluency. Cumulative vascular burden factors, with hypertension in particular, decreased left inferior frontal junction hemodynamic responses during phonological fluency. However, age and vascular burden factors showed no statistical interaction on functional hemodynamics. Based on these findings, one might hypothesize that increased fronto-parietal processing may represent age-related compensatory reorganization during increased cognitive demands. Vascular burden factors, such as hypertension, may contribute to regional cerebral hypoperfusion. These neural and vascular hemodynamic determinants should be investigated longitudinally and combined with other markers to advance the prediction of future cognitive decline and dementia.

Use of Frontal Lobe Hemodynamics as Reinforcement Signals to an Adaptive Controller

PubMed Central

DiStasio, Marcello M.; Francis, Joseph T.

2013-01-01

Decision-making ability in the frontal lobe (among other brain structures) relies on the assignment of value to states of the animal and its environment. Then higher valued states can be pursued and lower (or negative) valued states avoided. The same principle forms the basis for computational reinforcement learning controllers, which have been fruitfully applied both as models of value estimation in the brain, and as artificial controllers in their own right. This work shows how state desirability signals decoded from frontal lobe hemodynamics, as measured with near-infrared spectroscopy (NIRS), can be applied as reinforcers to an adaptable artificial learning agent in order to guide its acquisition of skills. A set of experiments carried out on an alert macaque demonstrate that both oxy- and deoxyhemoglobin concentrations in the frontal lobe show differences in response to both primarily and secondarily desirable (versus undesirable) stimuli. This difference allows a NIRS signal classifier to serve successfully as a reinforcer for an adaptive controller performing a virtual tool-retrieval task. The agent's adaptability allows its performance to exceed the limits of the NIRS classifier decoding accuracy. We also show that decoding state desirabilities is more accurate when using relative concentrations of both oxyhemoglobin and deoxyhemoglobin, rather than either species alone. PMID:23894500

[Hemodynamics variation in hypertensive pilots of polar transport aviation on different flight phases].

PubMed

Solov'eva, K B; Dolbin, I V; Koroleva, E B

2013-01-01

The purpose was to study in-flight blood pressure (BP) and heart rate (HR) in polar transport aviation pilots afflicted with essential hypertension. A total of 30 pilots were distributed into 2 groups: hypertensive pilots and those who, though generally healthy were, because of some conditions and lifestyle, predisposed to the cardiovascular risk (CVR). The examination included establishment of personal CVR factors, electrocardiography, bicycle ergometry, echocardiography, off-duty 24-hour BP and HR monitoring, and in-flight BP and HR monitoring. Maximum BP and HR values were higher in hypertensive pilots as compared with the control group. In the first group, maximum systolic BP (sBP) on the rise measured 202 mm Hg vs. 179 mm Hg in the control group. The highest HR on the rise was also registered in the first group (164 beats/min vs. 127 beats/min in the control). At landing, maximum sBP and HR made up 253 and 163 mm Hg, 150 and 141 beats/min values in groups first and second, respectively. To summarize, in the harsh weather conditions of Far North hypertensive pilots experience particularly heavy hemodynamic stresses during flight and, consequently, must be allowed to fly only if their hypertension is under control.

Novel Use of a Noninvasive Hemodynamic Monitor in a Personalized, Active Learning Simulation

ERIC Educational Resources Information Center

Zoller, Jonathan K.; He, Jianghua; Ballew, Angela T.; Orr, Walter N.; Flynn, Brigid C.

2017-01-01

The present study furthered the concept of simulation-based medical education by applying a personalized active learning component. We tested this novel approach utilizing a noninvasive hemodynamic monitor with the capability to measure and display in real time numerous hemodynamic parameters in the exercising participant. Changes in medical…

Treatment of post-cardiopulmonary bypass SIRS by hemoadsorption: a case series.

PubMed

Träger, Karl; Fritzler, Daniel; Fischer, Guenther; Schröder, Janpeter; Skrabal, Christian; Liebold, Andreas; Reinelt, Helmut

2016-05-16

The use of cardiopulmonary bypass (CPB) in cardiothoracic surgery results in a well-known activation of the immunologic response. In some cases, however, this triggered immunologic response may be excessive, leading to a severe systemic inflammatory response syndrome (SIRS) and induced organ dysfunction. For example, patients frequently develop hemodynamic instability with hypotension and low systemic vascular resistance. To date, different therapeutic approaches, such as steroids, have been tried to control this maladaptive postoperative SIRS response, yet definitive proof of clinical efficacy is missing. A new cytokine adsorber device (CytoSorb; CytoSorbents) may be a useful approach to control hyperinflammatory systemic reactions by reducing a broad range of proinflammatory cytokines and other inflammatory mediators. This may, in turn, help to reestablish a physiologic immune response and help to restore deranged clinical parameters in these patients. In this retrospective case series study, we describe 16 cardiac surgery patients following prolonged CPB with post-CPB SIRS and subsequent acute kidney injury, who were then treated with hemoadsorption using CytoSorb in combination with continuous renal replacement therapy (CRRT). Treatment of patients with CytoSorb who presented with severe post-CPB SIRS resulted in a reduction of elevated cytokine levels, which was associated with a clear stabilization of deranged hemodynamic, metabolic, and organ function parameters. Treatment was well tolerated and safe, with no device-related adverse events occurring. CytoSorb therapy combined with CRRT is a potentially promising new treatment approach to achieve hemodynamic stability, cytokine reduction, and improved organ function in cardiac surgery patients who develop post-CPB SIRS.

Medium-term methionine supplementation increases plasma homocysteine but not ADMA and improves blood pressure control in rats fed a diet rich in protein and adequate in folate and choline.

PubMed

Mariotti, François; Hammiche, Alexia; Blouet, Clémence; Daré, Sophie; Tomé, Daniel; Huneau, Jean François

2006-10-01

Hyperhomocysteinemia (HHcy) is associated with cardiovascular risk, possibly because it increases asymmetric dimethyl-arginine (ADMA), but the general association remains unclear and may vary with nutritional and physiological conditions. We aimed to monitor the effect of methionine supplementation, and subsequent HHcy, on plasma ADMA and hemodynamics in the context of a diet rich in protein and adequate in folic acid and choline. For 6 weeks, rats were fed a 29% protein diet supplemented (M) or not (C) with 8 g/kg L: -methionine. Blood pressure and plasma amino acids, including homocysteine and ADMA, were measured throughout the experiment and additional parameters, including in vivo hemodynamic response to acetylcholine, were measured at week 5-6. As compared to the C diet, the M diet induced a marked HHcy during the first 3 weeks, which lessened at week 5. In contrast, plasma ADMA stayed similar in the C and M diet. Paradoxically, M rats had lower mean and diastolic blood pressure values over the experiment, together with a lower left ventricular mass at week 6, when compared with C rats. No difference was observed between groups regarding vascular reactivity and plasma NOx at week 6. In a context of a diet rich in protein and adequate in methyl donors, rats exhibit a complex adaptation to the medium-term methionine supplementation, with improvement in blood pressure control despite marked HHcy. The lack of increase in plasma ADMA may account for the absence of detrimental effects of HHcy on hemodynamics.

Changes in Conjunctival Hemodynamics Predict Albuminuria in Sickle Cell Nephropathy

PubMed Central

Valeshabad, Ali Kord; Wanek, Justin; Saraf, Santosh L.; Gaynes, Bruce I.; Gordeuk, Victor R.; Molokie, Robert E.; Shahidi, Mahnaz

2015-01-01

Background Albuminuria is an early manifestation of deterioration in renal function in subjects with sickle cell disease (SCD). Hyperfiltration may be an early mechanism for kidney damage in SCD. The purpose of the current study was to determine the association between conjunctival hemodynamics and albuminuria in SCD subjects with preserved glomerular filtration rate. Methods Conjunctival microcirculation imaging was performed to measure conjunctival diameter (D) and axial blood velocity (V) in 35 SCD and 10 healthy control subjects. Albuminuria, defined as albumin excretion ratio (AER) was obtained from the medical charts. Based on the 95% confidence interval of conjunctival V in control subjects (0.40 - 0.60 mm/s), SCD subjects were allocated to three groups: V1 < 0.40 mm/s (N = 7), V2 of 0.40 – 0.60 mm/s (N = 18), and V3 ≥ 0.60 mm/s (N = 10). Results Mean log(AER) measurements in the V1, V2, and V3 groups were 1.08 ± 0.67 mg/g creatinine, 1.39 ± 0.59 mg/g creatinine, and 2.00 ± 0.91 mg/g creatinine, respectively, and followed a positive linear trend from the V1 to V3 groups (p = 0.01). By multivariate linear regression analysis, conjunctival V significantly correlated with albuminuria (p = 0.01) independent of age, blood pressure, α-thalassemia, hematocrit, white blood cell count, and lactate dehydrogenase concentration. Conclusions Increased conjunctival velocity is associated with albuminuria in sickle cell subjects. Assessment of conjunctival microvascular hemodynamics may improve our understanding of the pathophysiology and clinical course of sickle cell nephropathy. PMID:26278102

Hemodynamic and tissue oxygenation responses to exercise and beta-adrenergic blockade in patients with hyperthyroidism.

PubMed

Monachini, Maristela C; Lage, Silvia G; Ran, Miguel A N; Cardoso, Rita H A; Medeiros, Caio; Caramelli, Bruno; Sposito, Andrei C; Ramires, José A F

2004-07-01

Exercise-induced dyspnea is a frequent feature in patients with hyperthyroidism. Data from clinical studies to elucidate the origin of this symptom are lacking. In the current study, we examined the hemodynamic and oxygenation responses to exercise and beta-adrenergic blockade in patients with hyperthyroidism and their relationship with dyspnea. Hemodynamic studies were performed under resting conditions and after isotonic exercise in 15 patients with hyperthyroidism and 11 control subjects. Exercise was applied using a bicycle ergometer, with progressive loads. In the hyperthyroid group, measurements were repeated at rest and during supine exercise after administering 15 mg of intravenous metoprolol. End-diastolic pulmonary artery pressure and cardiac index were higher in the hyperthyroid group than in controls (18.6 +/- 5.3 vs. 11.2 +/- 4.9 mmHg; p = 0.02, and 6.0 +/- 1.7 vs. 2.8 +/- 0.5 l/min/m2; p = 0.0001, respectively). After exercise, there was an increase in end-diastolic pulmonary artery pressure in the hyperthyroid group (18.6 +/- 5.3 to 25.5 +/- 9.9 mmHg; p = 0.02), revealing impaired cardiocirculatory reserve. Pulmonary arteriolar resistance increased significantly in parallel with end-diastolic pulmonary artery pressure after drug administration, suggesting an inadequate cardiovascular response after beta blockade in patients with hyperthyroidism. We observed that functional left ventricular reserve is impaired in patients with hyperthyroidism, suggesting an explanation for the frequent symptom of dyspnea and impaired exercise tolerance. Moreover, we also suggest that beta-adrenergic blockade may adversely affect cardiovascular function in patients with hyperthyroidism.

Autologous Peripheral Blood Stem Cell Transplantation Improves Portal Hemodynamics in Patients with Hepatitis B Virus-related Decompensated Cirrhosis.

PubMed

Deng, Qinzhi; Cai, Ting; Zhang, Shun; Hu, Airong; Zhang, Xingfen; Wang, Yinyin; Huang, Jianrong

2015-12-01

Chronic hepatitis B virus (HBV) infection may eventually lead to decompensated liver cirrhosis, which is a terminal illness. The aim of this study was to investigate the therapeutic efficacy of autologous peripheral blood stem cell (APBSC) transplantation to improve portal vein hemodynamics in patients with HBV-related decompensated cirrhosis. This prospective study included 68 hospitalized patients who were diagnosed with HBV-related decompensated cirrhosis. These patients were divided into two groups: the transplantation group included 33 patients, while the control group included 35. Both groups received conventional medical treatment simultaneously, and APBSC transplantation was performed on the patients in the transplantation group. We evaluated the effects of APBSC transplantation on postoperative liver function using the following indices: total bilirubin, serum prothrombin and albumin, spleen size, and portal vein hemodynamics. Postoperatively, all of the patients were followed up at 24, 36, and 48 weeks. The transplantation group had no serious reactions. Compared with the control group, albumin and prothrombin activity in the transplantation group was significantly improved at 24, 36, and 48 weeks after the procedure, and spleen length and portal vein diameter were substantially reduced at 48 weeks. The velocity of peak portal vein blood flow and mean maximum portal vein blood flow were greatly increased in the APBSC transplantation group at 36 and 48 weeks, respectively; however, there was also decreased portal vein diameter, which reduced portal vein pressure in patients with HBV-related decompensated cirrhosis. APBSC transplantation greatly benefits HBV-linked decompensated cirrhosis patients and should be recommended in clinical practice.

C-peptide does not affect ocular blood flow in patients with type 1 diabetes.

PubMed

Polska, Elzbieta; Kolodjaschna, Julia; Berisha, Fatmire; Malec, Maria M; Simader, Christian; Bayerle-Eder, Michaela; Roden, Michael; Schmetterer, Leopold

2006-09-01

The aim of the present study was to investigate the effect of intravenous C-peptide infusion on ocular blood flow in patients with type 1 diabetes under euglycemic conditions. The study was performed in a randomized, placebo-controlled, double-masked, two-way, crossover design in 10 type 1 diabetic patients. C-peptide was intravenously administered at two different dosages (dosage 1: 25 pmol . kg(-1) . min(-1) bolus followed by 5 pmol . kg(-1) . min(-1) continuous infusion; dosage 2: six times higher than dosage 1), each for 60 min. Physiologic saline solution was used as a control for C-peptide on a different study day. On both study days, euglycemic clamps were performed. To assess retinal blood flow, laser Doppler velocimetry (blood flow velocities) and retinal vessel analyzer (vessels diameters) measurements were performed. Laser interferometric measurements of fundus pulsation were used to assess pulsatile choroidal blood flow. Blood velocities in the ophthalmic artery were measured using color Doppler imaging. Eight patients (two female and six male) completed the study according to the protocol and without adverse events. One patient developed an anaphylactic reaction to C-peptide, which resolved without sequelae. The following results originate from the remaining eight subjects. Systemic hemodynamic parameters remained stable during both study days. Infusion of C-peptide did not affect any ocular hemodynamic parameter. The data of the present study indicate that exogenous C-peptide exerts no effect on ocular hemodynamic parameters in type 1 diabetic patients under euglycemic conditions. The maximum detectable change in these parameters was <25%.

Hemodynamic response to intravitreal triamcinolone in eyes with macular edema: intravitreal triamcinolone and ocular blood flow.

PubMed

Cekiç, Osman; Bardak, Yavuz; Tiğ, Sahin U; Demirkol, Aykut; Ekim, Mustafa M; Altintaş, Onem; Yeşildağ, Ahmet; Oyar, Orhan

2007-10-01

To assess ocular hemodynamic response to intravitreal triamcinolone in patients with macular edema due to diabetes or retinal vein occlusion. Forty-three patients that were injected by intravitreal triamcinolone acetonide (0.1 cc 4 mg) for unilateral macular edema due to diabetes mellitus (n = 17) and occlusion of retinal vein (n = 26) underwent ocular hemodynamic evaluation by color Doppler imaging (CDI) before and one, two and three months after injection. Non-injected fellow eyes as well as 16 healthy volunteers were also evaluated. In patients with diabetic macular edema, there was no hemodynamic difference between eyes to be injected and non-injected at baseline (P > 0.23). Compared to controls, a significant difference existed in the ophthalmic artery resistant index (P = 0.001) and end-diastolic velocity (P < 0.001) in diabetics. At one month, compared to fellow eyes, change in end diastolic velocity from baseline in treated eyes was significantly decreased in posterior ciliary arteries (0.68 +/- 0.34 cm/s [mean +/- SEM] vs. -1.04 +/- 0.81 cm/s, P = 0.012). Throughout the study period, no significant alteration from baseline in the resistant index of any artery was noted in treated diabetic eyes (P > 0.05). In eyes with retinal vein occlusion, baseline CDI evaluation demonstrated reduced posterior ciliary arteries systolic flow velocity compared to fellow and control eyes (13.24 +/- 1.04 cm/s, 16.37 +/- 0.76 cm/s and 14.33 +/- 1.41 cm/s, respectively, P = 0.007). Increased peak systolic velocity in the posterior ciliary arteries at one week (P = 0.02), one month (P = 0.005) and two months (P = 0.04), and increase in central retinal artery resistant index at one month was noted (P = 0.05). Intravitreal triamcinolone temporarily changed central retinal artery blood flow and posterior ciliary arteries' peak systolic blood velocity in eyes with retinal vein occlusion whilst no response of blood flow to triamcinolone injection but only transiently altered end diastolic blood velocity in posterior ciliary arteries was observed in diabetic eyes.

Enhanced pulmonary vasodilator reserve and abnormal right ventricular: pulmonary artery coupling in heart failure with preserved ejection fraction.

PubMed

Andersen, Mads J; Hwang, Seok-Jae; Kane, Garvan C; Melenovsky, Vojtech; Olson, Thomas P; Fetterly, Kenneth; Borlaug, Barry A

2015-05-01

Pulmonary hypertension and right ventricular (RV) dysfunction are common in patients with advanced heart failure with preserved ejection fraction (HFpEF), yet their underlying mechanisms remain poorly understood. We sought to examine RV-pulmonary artery (PA) functional reserve responses and RV-PA coupling at rest and during β-adrenergic stimulation in subjects with earlier stage HFpEF. In a prospective trial, subjects with HFpEF (n=39) and controls (n=18) underwent comprehensive invasive and noninvasive hemodynamic assessment using high fidelity micromanometer catheters, echocardiography, and expired gas analysis at rest and during dobutamine infusion. HFpEF subjects displayed similar RV structure but significantly impaired RV systolic (lower RV dP/dtmax/IP and s') and diastolic function (higher RV τ) coupled with more severe pulmonary vascular disease, manifest by higher PA pressures, higher PA resistance, and lower PA compliance compared with controls. Dobutamine infusion caused greater pulmonary vasodilation in HFpEF compared with controls, with enhanced reductions in PA resistance, greater increase in PA compliance, and a more negative slope in the PA pressure-flow relationship when compared with controls (all P<0.001). RV-PA coupling analysis revealed that dobutamine improved RV ejection in HFpEF subjects through afterload reduction alone, rather than through enhanced contractility, indicating RV systolic reserve dysfunction. Pulmonary hypertension in early stage HFpEF is related to partially reversible pulmonary vasoconstriction coupled with RV systolic and diastolic dysfunction, even in the absence of RV structural remodeling. Pulmonary vascular tone is more favorably responsive to β-adrenergic stimulation in HFpEF than controls, suggesting a potential role for β-agonists in the treatment of patients with HFpEF and pulmonary hypertension. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01418248. © 2015 American Heart Association, Inc.

Comparison of spectral entropy and BIS VISTA™ monitor during general anesthesia for cardiac surgery.

PubMed

Musialowicz, Tadeusz; Lahtinen, Pasi; Pitkänen, Otto; Kurola, Jouni; Parviainen, Ilkka

2011-04-01

We compared the primary metrics of the Spectral entropy M-ENTROPY™ module and BIS VISTA™ monitor-i.e., bispectral index (BIS), state entropy (SE), and response entropy (RE) in terms of agreement and correlation during general anesthesia for cardiac surgery. We also evaluated responsiveness of electroencephalogram (EEG)-based and hemodynamic parameters to surgical noxious stimulation, skin incision, and sternotomy, hypothesizing that RE would be a better responsiveness predictor. BIS and entropy sensors were applied before anesthesia induction in 32 patients having elective cardiac surgery. Total intravenous anesthesia was standardized and guided by the BIS index with neuromuscular blockade tested with train-of-four monitoring. Parameters included SE, RE, BIS, forehead electromyography (EMG), and hemodynamic variables. Time points for analyzing BIS, entropy, and hemodynamic values were 1 min before and after: anesthesia induction, intubation, skin incision, sternotomy, cannulation of the aorta, cardiopulmonary bypass (CPB), cross-clamping the aorta, de-clamping the aorta, and end of CPB; also after starting the re-warming phase and at 10, 20, 30, and 40 min following. The mean difference between BIS and SE (Bland-Altman) was 2.14 (+16/- 11; 95% CI 1.59-2.67), and between BIS and RE it was 0.02 (+14/- 14; 95% CI 0.01-0.06). BIS and SE (r(2) = 0.66; P = 0.001) and BIS and RE (r(2) = 0.7; P = 0.001) were closely correlated (Pearson's). EEG parameters, EMG values, and systolic blood pressure significantly increased after skin incision, and sternotomy. The effect of surgical stimulation (Cohen's d) was highest for RE after skin incision (-0.71; P = 0.0001) and sternotomy (-0.94; P = 0.0001). Agreement was poor between the BIS index measured by BIS VISTA™ and SE values at critical anesthesia time points in patients undergoing cardiac surgery. RE was a good predictor of arousal after surgical stimulation regardless of the surgical level of muscle relaxation. Index differences most likely resulted from different algorithms for calculating consciousness level.

Hemodynamic and respiratory factors that influence the opening of patent foramen ovale in mechanically ventilated patients.

PubMed

Vavlitou, A; Minas, G; Zannetos, S; Kyprianou, T; Tsagourias, M; Matamis, D

2016-01-01

Patent foramen ovale (PFO) is an anatomic variant that may lead to several pathological conditions, notably right to left shunt, paradoxical embolism, hypoxemia, and cerebral fat embolism. Mechanical positive pressure ventilation may increase the prevalence of PFO opening in Intensive Care Unit (ICU) patients; however, the respiratory and hemodynamic determinants of PFO opening have been poorly investigated. Contrast-enhanced transesophageal echocardiogram (ce-TEE) is considered the gold standard for PFO detection. We prospectively performed a multicenter study using ce-TEE in order to determine the respiratory and hemodynamic factors that may lead to PFO opening. One hundred and eight consecutive ICU adult patients under mechanical ventilation from three tertiary care hospitals, were included in the study. A standard multiplane ce-TEE was performed, and the dimensions and function of the right and left ventricle were studied. In each patient, the right ventricle (RV) end-diastolic area, RV end-systolic area, left ventricle (LV) end-diastolic area, and LV ejection fraction were measured using the modified Simpson's rule and the four-chamber view. At least three bubble tests were performed to detect PFO opening. Ventilatory parameters such as tidal volume, plateau pressure, static lung compliance, and positive end-expiratory pressure were recorded during the bubble test. Data for 81 men and 27 women were analyzed. PFO was detected in 27 % of the study population. Statistical significance was found between the presence of PFO and plateau pressure (odds ratio 3.421, 95 % CI: 1.2-9.4, p =0.017). Additionally, the presence of right ventricular dilatation (RV>LV) was strongly associated with PFO opening (odds ratio 3.163, 95 % CI: 1.2-8.075, p =0.018). In this group of mechanically ventilated, critically ill adult patients, right ventricular dilatation and plateau pressure above 26 mmHg were significantly associated with foramen ovale opening. Hippokratia 2016, 20(3): 209-213.

Heart Rate Variability during Simulated Hemorrhage with Lower Body Negative Pressure in High and Low Tolerant Subjects.

PubMed

Hinojosa-Laborde, Carmen; Rickards, Caroline A; Ryan, Kathy L; Convertino, Victor A

2011-01-01

Heart rate variability (HRV) decreases during hemorrhage, and has been proposed as a new vital sign to assess cardiovascular stability in trauma patients. The purpose of this study was to determine if any of the HRV metrics could accurately distinguish between individuals with different tolerance to simulated hemorrhage. Specifically, we hypothesized that (1) HRV would be similar in low tolerant (LT) and high tolerant (HT) subjects at presyncope when both groups are on the verge of hemodynamic collapse; and (2) HRV could distinguish LT subjects at presyncope from hemodynamically stable HT subjects (i.e., at a submaximal level of hypovolemia). Lower body negative pressure (LBNP) was used as a model of hemorrhage in healthy human subjects, eliciting central hypovolemia to the point of presyncopal symptoms (onset of hemodynamic collapse). Subjects were classified as LT if presyncopal symptoms occurred during the -15 to -60 mmHg levels of LBNP, and HT if symptoms occurred after LBNP of -60 mmHg. A total of 20 HRV metrics were derived from R-R interval measurements at the time of presyncope, and at one level prior to presyncope (submax) in LT and HT groups. Only four HRV metrics (Long-range Detrended Fluctuation Analysis, Forbidden Words, Poincaré Plot Descriptor Ratio, and Fractal Dimensions by Curve Length) supported both hypotheses. These four HRV metrics were evaluated further for their ability to identify individual LT subjects at presyncope when compared to HT subjects at submax. Variability in individual LT and HT responses was so high that LT responses overlapped with HT responses by 85-97%. The sensitivity of these HRV metrics to distinguish between individual LT from HT subjects was 6-33%, and positive predictive values were 40-73%. These results indicate that while a small number of HRV metrics can accurately distinguish between LT and HT subjects using group mean data, individual HRV values are poor indicators of tolerance to hypovolemia.

A method to quantify mechanobiologic forces during zebrafish cardiac development using 4-D light sheet imaging and computational modeling

PubMed Central

Vedula, Vijay; Lee, Juhyun; Xu, Hao; Hsiai, Tzung K.

2017-01-01

Blood flow and mechanical forces in the ventricle are implicated in cardiac development and trabeculation. However, the mechanisms of mechanotransduction remain elusive. This is due in part to the challenges associated with accurately quantifying mechanical forces in the developing heart. We present a novel computational framework to simulate cardiac hemodynamics in developing zebrafish embryos by coupling 4-D light sheet imaging with a stabilized finite element flow solver, and extract time-dependent mechanical stimuli data. We employ deformable image registration methods to segment the motion of the ventricle from high resolution 4-D light sheet image data. This results in a robust and efficient workflow, as segmentation need only be performed at one cardiac phase, while wall position in the other cardiac phases is found by image registration. Ventricular hemodynamics are then quantified by numerically solving the Navier-Stokes equations in the moving wall domain with our validated flow solver. We demonstrate the applicability of the workflow in wild type zebrafish and three treated fish types that disrupt trabeculation: (a) chemical treatment using AG1478, an ErbB2 signaling inhibitor that inhibits proliferation and differentiation of cardiac trabeculation; (b) injection of gata1a morpholino oligomer (gata1aMO) suppressing hematopoiesis and resulting in attenuated trabeculation; (c) weak-atriumm58 mutant (wea) with inhibited atrial contraction leading to a highly undeveloped ventricle and poor cardiac function. Our simulations reveal elevated wall shear stress (WSS) in wild type and AG1478 compared to gata1aMO and wea. High oscillatory shear index (OSI) in the grooves between trabeculae, compared to lower values on the ridges, in the wild type suggest oscillatory forces as a possible regulatory mechanism of cardiac trabeculation development. The framework has broad applicability for future cardiac developmental studies focused on quantitatively investigating the role of hemodynamic forces and mechanotransduction during morphogenesis. PMID:29084212

Improved hemodynamic parameters in middle cerebral artery infarction after decompressive craniectomy.

PubMed

Amorim, Robson Luis; de Andrade, Almir Ferreira; Gattás, Gabriel S; Paiva, Wellingson Silva; Menezes, Marcos; Teixeira, Manoel Jacobsen; Bor-Seng-Shu, Edson

2014-05-01

Decompressive craniectomy (DC) reduces mortality and improves functional outcome in patients with malignant middle cerebral artery infarction. However, little is known regarding the impact of DC on cerebral hemodynamics. Therefore, our goal was to study the hemodynamic changes that may occur in patients with malignant middle cerebral artery infarction after DC and to assess their relationship with outcomes. Twenty-seven patients with malignant middle cerebral artery infarction who were treated with DC were studied. The perfusion CT hemodynamic parameters, mean transit time, cerebral blood flow, and cerebral blood volume were evaluated preoperatively and within the first 24 hours after DC. There was a global trend toward improved cerebral hemodynamics after DC. Preoperative and postoperative absolute mean transit times were associated with mortality at 6 months, and the ratio of post- and preoperative cerebral blood flow was significantly higher in patients with favorable outcomes than those with unfavorable outcomes. Patients who underwent surgery 48 hours after stroke, those with midline brain shift>10 mm, and those who were >55 years showed no significant improvement in any perfusion CT parameters. DC improves cerebral hemodynamics in patients with malignant middle cerebral artery infarction, and the level of improvement is related to outcome. However, some patients did not seem to experience any additional hemodynamic benefit, suggesting that perfusion CT may play a role as a prognostic tool in patients undergoing DC after ischemic stroke.

Echocardiographic parameters predicting acute hemodynamically significant mitral regurgitation during transfemoral transcatheter aortic valve replacement.

PubMed

Ito, Asahiro; Iwata, Shinichi; Mizutani, Kazuki; Nonin, Shinichi; Nishimura, Shinsuke; Takahashi, Yosuke; Yamada, Tokuhiro; Murakami, Takashi; Shibata, Toshihiko; Yoshiyama, Minoru

2018-03-01

Alteration in mitral valve morphology resulting from retrograde stiff wire entanglement sometimes causes hemodynamically significant acute mitral regurgitation (MR) during transfemoral transcatheter aortic valve replacement (TAVR). Little is known about the echocardiographic parameters related to hemodynamically significant acute MR. This study population consisted of 64 consecutive patients who underwent transfemoral TAVR. We defined hemodynamically significant acute MR as changes in the severity of MR with persistent hypotension (systolic blood pressure < 80-90 mm Hg or mean arterial pressure 30 mm Hg lower than baseline). Hemodynamically significant acute MR occurred in 5 cases (7.8%). Smaller left ventricular end-systolic diameter (LVDs), larger ratios of the coiled section of stiff wire tip to LVDs (wire-width/LVDs), and higher Wilkins score were significantly associated with hemodynamically significant acute MR (P < .05), whereas the parameters of functional MR (annular area, anterior-posterior diameter, tenting area, and coaptation length) were not. Moreover, when patients were divided into 4 groups according to wire-width/LVDs and Wilkins score, the group with the larger wire-width/LVDs and higher Wilkins score improved prediction rates (P < .05). Small left ventricle or wire oversizing and calcific mitral apparatus were predictive of hemodynamically significant acute MR. These findings are important for risk stratification, and careful monitoring using intraoperative transesophageal echocardiography may improve the safety in this population. © 2017, Wiley Periodicals, Inc.

Management dilemma in penetrating head injuries in comatose patients: Scenario in underdeveloped countries

PubMed Central

Wani, Abrar Ahad; Ramzan, Altaf Umar; Dar, Tanveer Iqbal; Malik, Nayil K.; Khan, Abdul Quyoom; Wani, Mohd Afzal; Alam, Shafeeq; Nizami, Furqan A.

2012-01-01

Background: The optimal management of patients with minimal injury to brain has been a matter of controversy and this is especially intensified when the patient has a poor neurological status. This is important in the regions where neurosurgical services are limited and patient turnover is disproportionate to the available resources. We aimed to determine the effectiveness of aggressive management in coma patients after penetrating missile injuries of the brain. Methods: All the patients of gunshots or blast injuries were included if they had a Glasgow Coma Scale score of less than 8 after initial resuscitation and had no other injury that could explain their poor neurological status. The indication for emergency surgery was evidence of a mass lesion causing a significant mass effect; otherwise, debridement was done in a delayed fashion. The patients who were not operated were those with irreversible shock or having small intracranial pellets with no significant scalp wounds. The patients who had a Glasgow outcome score of 1, 2, or 3 were classified as having an unfavorable outcome (UO) and those with scores 4 and 5 were classified as having a favorable outcome (FO). Results: We operated 13 patients and the rest 13 were managed conservatively. The characteristics of the patients having a favorable outcome were young age (OR = 28, P = 0 .031), normal hemodynamic status (OR = 18, P = 0.08), presence of pupillary reaction (OR = 9.7, P = 0.1), and injury restricted to one hemisphere only (OR = 15, P = 0.07). All of the patients who were in shock after resuscitation died while 25% of the patients with a normal hemodynamic status had a favorable outcome. Conclusions: In developing countries with limited resources, the patients who are in a comatose condition after sustaining penetrating missile injuries should not be managed aggressively if associated with bihemispheric damage, irreversible shock, or bilateral dilated nonreacting pupils. This is especially important in the event of receiving numerous patients with the same kind of injuries. PMID:23050203

Hemodynamic Characteristics Including Pulmonary Hypertension at Rest and During Exercise Before and After Heart Transplantation

PubMed Central

Lundgren, Jakob; Rådegran, Göran

2015-01-01

Background Little is known about the hemodynamic response to exercise in heart failure patients at various ages before and after heart transplantation (HT). This information is important because postoperative hemodynamics may be a predictor of survival. To investigate the hemodynamic response to HT and exercise, we grouped our patients based on preoperative age and examined their hemodynamics at rest and during exercise before and after HT. Methods and Results Ninety-four patients were evaluated at rest prior to HT with right heart catheterization at our laboratory. Of these patients, 32 were evaluated during slight supine exercise before and 1 year after HT. Postoperative evaluations were performed at rest 1 week after HT and at rest and during exercise at 4 weeks, 3 months, 6 months, and 1 year after HT. The exercise patients were divided into 2 groups based on preoperative age of ≤50 or >50 years. There were no age-dependent differences in the preoperative hemodynamic exercise responses. Hemodynamics markedly improved at rest and during exercise at 1 and 4 weeks, respectively, after HT; however, pulmonary and, in particular, ventricular filling pressures remained high during exercise at 1 year after HT, resulting in normalized pulmonary vascular resistance response but deranged total pulmonary vascular resistance response. Conclusions Our findings suggest that, (1) in patients with heart failure age ≤50 or >50 years may not affect the hemodynamic response to exercise to the same extent as in healthy persons, and (2) total pulmonary vascular resistance may be more adequate than pulmonary vascular resistance for evaluating the exercise response after HT. PMID:26199230

Progressive Cortical Neuronal Damage and Chronic Hemodynamic Impairment in Atherosclerotic Major Cerebral Artery Disease.

PubMed

Yamauchi, Hiroshi; Kagawa, Shinya; Kishibe, Yoshihiko; Takahashi, Masaaki; Higashi, Tatsuya

2016-06-01

Cross-sectional studies suggest that chronic hemodynamic impairment may cause selective cortical neuronal damage in patients with atherosclerotic internal carotid artery or middle cerebral artery occlusive disease. The purpose of this longitudinal study was to determine whether the progression of cortical neuronal damage, evaluated as a decrease in central benzodiazepine receptors (BZRs), is associated with hemodynamic impairment at baseline or hemodynamic deterioration during follow-up. We evaluated the distribution of BZRs twice using positron emission tomography and (11)C-flumazenil over time in 80 medically treated patients with atherosclerotic internal carotid artery or middle cerebral artery occlusive disease that had no ischemic episodes during follow-up. Using 3D stereotactic surface projections, we quantified abnormal decreases in the BZRs in the cerebral cortex within the middle cerebral artery distribution and correlated changes in the BZR index with the mean hemispheric values of hemodynamic parameters obtained from (15)O gas positron emission tomography. In the hemisphere affected by arterial disease, the BZR index in 40 patients (50%) was increased during follow-up (mean 26±20 months). In multivariable logistic regression analyses, increases in the BZR index were associated with the decreased cerebral blood flow at baseline and an increased oxygen extraction fraction during follow-up. Increases in the oxygen extraction fraction during follow-up were associated with a lack of statin use. In patients with atherosclerotic internal carotid artery or middle cerebral artery disease, the progression of cortical neuronal damage was associated with hemodynamic impairment at baseline and hemodynamic deterioration during follow-up. Statin use may be beneficial against hemodynamic deterioration and therefore neuroprotective. © 2016 American Heart Association, Inc.

Application of CT perfusion to assess hemodynamics in symptomatic Moyamoya syndrome: focus on affected side and parameter characteristic.

PubMed

Huang, Shuran; Gao, Lingyun; Chen, Yueqin; Guo, Xiang; Liu, Deguo; Wang, Jiehuan; Shi, Zhitao; Sun, Zhanguo; Jin, Feng; Chen, Weijian; Yang, Yunjun

2018-01-27

Vascular and hemodynamic changes were not consistent in symptomatic and non-symptomatic cerebral hemisphere in patients with symptomatic moyamoya syndrome (MMS). Thus, the purpose of this study is to evaluate the hemodynamic difference between symptomatic and non-symptomatic cerebral hemisphere in patients with symptomatic MMS. Patients who were diagnosed with symptomatic MMS were retrospectively collected. All cases underwent CTP examination. Regions of interest (ROIs) were chosen in the mirroring bilateral frontal lobes, temporal lobes, the basal ganglia, and the brainstem as control region. The relative perfusion parameter values of symptomatic side were compared with non-symptomatic side. Of the 40 patients, 33 patients were taken into assessment. In all cases (n = 33), rCBF, rMTT, and rTTP in all regions of interest (ROIs) of the symptomatic side were significantly different from those of contralateral side. In unilateral MMS patients (n = 7), rCBF values were not significantly different between two sides in the temporal lobe and basal ganglia area; rTTP values were significantly higher in the symptomatic side. rMTT values were significantly higher only in the temporal lobe of symptomatic side. In bilateral MMS patients (n = 26), rCBF and rMTT in all ROIs of the symptomatic side were significantly different from those of contralateral side. However, there were no significant differences between two sides in all ROIs on rTTP values. This study demonstrates that rCBF and rMTT were more sensitive than rTTP for evaluating hemodynamic changes in patients with symptomatic bilateral MMS. Furthermore, patients with unilateral MMS may have a preserved rCBF compared to those with bilateral disease.

Hemodynamic and hormonal responses to lower body negative pressure in men with varying profiles of strength and aerobic power

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Mathes, K. L.; Lasley, M. L.; Tomaselli, C. M.; Frey, M. A.; Hoffler, G. W.

1993-01-01

Hemodynamic, cardiac, and hormonal responses to lower-body negative pressure (LBNP) were examined in 24 healthy men to test the hypothesis that responsiveness of reflex control of blood pressure during orthostatic challenge is associated with interactions between strength and aerobic power. Subjects underwent treadmill tests to determine peak oxygen uptake (VO2max) and isokinetic dynamometer tests to determine knee extensor strength. Based on predetermined criteria, subjects were classified into one of four fitness profiles of six subjects each, matched for age, height, and body mass: (a) low strength/average aerobic fitness, (b) low strength/high aerobic fitness, (c) high strength/average aerobic fitness, and (d) high strength/high aerobic fitness. Following 90 min of 0.11 rad (6 degrees) head-down tilt (HDT), each subject underwent graded LBNP to -6.7 kPa or presyncope, with maximal duration 15 min, while hemodynamic, cardiac, and hormonal responses were measured. All groups exhibited typical hemodynamic, hormonal, and fluid shift responses during LBNP, with no intergroup differences between high and low strength characteristics. Subjects with high aerobic power exhibited greater (P < 0.05) stroke volume and lower (P < 0.05) heart rate, vascular peripheral resistance, and mean arterial pressure during rest, HDT, and LBNP. Seven subjects, distributed among the four fitness profiles, became presyncopal. These subjects showed greatest reduction in mean arterial pressure during LBNP, had greater elevations in vasopressin, and lesser increases in heart rate and peripheral resistance. Neither VO2max nor leg strength were associated with fall in arterial pressure or with syncopal episodes. We conclude that interactions between aerobic and strength fitness characteristics do not influence responses to LBNP challenge.

Effects of 12 days exposure to simulated microgravity on central circulatory hemodynamics in the rhesus monkey

NASA Astrophysics Data System (ADS)

Convertino, V. A.; Koenig, S. C.; Krotov, V. P.; Fanton, J. W.; Korolkov, V. I.; Trambovetsky, E. V.; Ewert, D. L.; Truzhennikov, A.; Latham, R. D.

Central circulatory hemodynamic responses were measured before and during the initial 9 days of a 12-day 10 ° head-down tilt (HDT) in 4 flight-sized juvenile rhesus monkeys who were surgically instrumented with a variety of intrathoracic catheters and blood flow sensors to assess the effects of simulated microgravity on central circulatory hemodynamics. Each subject underwent measurements of aortic and left ventricular pressures, and aortic flow before and during HDT as well as during a passive head-up postural test before and after HDT. Heart rate, stroke volume, cardiac output, and left ventricular end-diastolic pressure were measured, and dP/dt and left ventricular elastance was calculated from hemodynamic measurements. The postural test consisted of 5 min of supine baseline control followed by 5 minutes of 90 ° upright tilt (HUT). Heart rate, stroke volume, cardiac output, and left ventricular end-diastolic pressure showed no consistent alterations during HDT. Left ventricular elastance was reduced in all animals throughout HDT, indicating that cardiac compliance was increased. HDT did not consistently alter left ventricular +dP/dt, indicating no change in cardiac contractility. Heart rate during the post-HDT HUT postural test was elevated compared to pre-HDT while post-HDT cardiac output was decreased by 52% as a result of a 54% reduction in stroke volume throughout HUT. Results from this study using an instrumented rhesus monkey suggest that exposure to microgravity may increase ventricular compliance without alterating cardiac contractility. Our project supported the notion that an invasively-instrumented animal model should be viable for use in spaceflight cardiovascular experiments to assess potential changes in myocardial function and cardiac compliance.

A combination of levobupivacaine and lidocaine for paravertebral block in breast cancer patients undergoing quadrantectomy causes greater hemodynamic oscillations than levobupivacaine alone

PubMed Central

Župčić, Miroslav; Graf, Sandra; Župčić; Duzel, Viktor; Šimurina, Tatjana; Šakić, Livija; Fudurić, Jurica; Peršec, Jasminka; Milošević, Milan; Stanec, Zdenko; Korušić, Anđelko; Barišin, Stjepan

2017-01-01

Aim To test for differences in hemodynamic and analgesic properties in patients with breast cancer undergoing quadrantectomy with paravertebral block (PVB) induced with a solution of either one or two local anesthetics. Method A prospective, single-center, randomized, double-blinded, controlled trial was conducted from June 2014 until September 2015. A total of 85 women with breast cancer were assigned to receive PVB with either 0.5% levobupivacaine (n = 42) or 0.5% levobupivacaine with 2% lidocaine (n = 43). Hemodynamic variables of interest included intraoperative stroke volume variation (SVV), mean arterial pressure, heart rate, cardiac output, episodes of hypotension, use of crystalloids, and use of inotropes. Analgesic variables of interest were time to block onset, duration of analgesia, and postoperative serial pain assessment using a visual analogue scale. Results Although the use of 0.5% levobupivacaine with 2% lidocaine solution for PVB decreased the mean time-to-block onset (14 minutes; P < 0.001), it also caused significantly higher SVV values over the 60 minutes of monitoring (mean difference: 4.33; P < 0.001). Furthermore, the patients who received 0.5% levobupivacaine with 2% lidocaine experienced shorter mean duration of analgesia (105 minutes; P = 0.006) and more episodes of hypotension (17.5%; P = 0.048) and received more intraoperative crystalloids (mean volume: 550 mL; P < 0.001). Conclusion The use of 0.5% levobupivacaine in comparison with 0.5% levobupivacaine with 2% lidocaine solution for PVB had a longer time-to-block onset, but it also reduced hemodynamic disturbances and prolonged the analgesic effect. Registration No.: NTC02004834 PMID:28857520

The effects of therapeutic exercises on pain, muscle strength, functional capacity, balance and hemodynamic parameters in knee osteoarthritis patients: a randomized controlled study of supervised versus home exercises.

PubMed

Kuru Çolak, Tuğba; Kavlak, Bahar; Aydoğdu, Onur; Şahin, Emir; Acar, Gönül; Demirbüken, İlkşan; Sarı, Zübeyir; Çolak, İlker; Bulut, Güven; Polat, M Gülden

2017-03-01

The aim of the study was to compare the effects of low-intensity exercise programs for lower extremities, either supervised or at home, on pain, muscle strength, balance and the hemodynamic parameters of knee osteoarthritis (OA) patients. This randomized study included 78 patients with knee OA in 2 groups of supervised and home-based exercise program. Exercises were applied to the first group in the clinic as a group exercise program and were demonstrated to the second group to be performed at home. Before and after the 6-week exercise program, assessment was made of pain, quadriceps and hamstring muscle strengths, 6-min walk test (6MWT), and non-invasive hemodynamic parameters. Results of the 78 patients, 56 completed the study. Pain, muscle strength, and 6MWT scores showed significant improvements in both groups. There were also significant differences in the amount of change in pain and muscle strength (pain: p = 0.041, Rqdc: 0.009, Lqdc: 0.013, Rhms: 0.04) which indicated greater improvements in the supervised group. The balance scores of supervised group showed a significant improvement (p = 0.009). No significant change was determined in hemodynamic parameters of either group. Conclusion according to the results of this study showed that low-intensity lower extremity exercises conducted in a clinic under the supervision of a physiotherapist were more effective than home-based exercises in reducing post-activity pain levels and improving quadriceps and right hamstring muscle strength. Both the supervised and home exercise programs were seen to be effective in reducing rest pain and increasing 6 MW distance in knee osteoarthritis patients.

Amelioration of cardio-respiratory perturbations following Mesobuthus eupeus envenomation in anesthetized rabbits with commercial polyvalent F(ab')2 antivenom.

PubMed

Zayerzadeh, Ehsan; Koohi, Mohammad Kazem; Mirakabadi, Abbas Zare; Fardipoor, Azadeh; Kassaian, Seyed Ebrahim; Rabbani, Shahram; Anvari, Maryam Sotoudeh

2012-02-01

Immunotherapy is the only specific treatment for scorpion sting. In the present study, protective effects of polyvalent antivenom against hemodynamic disturbances, biomarkers (troponin T, creatinine kinase isoenzyme MB, Lactate dehydrogenase) changes, electrocardiogram abnormalities and histopathological complications in heart and lung induced by Mesobuthus eupeus scorpion venom was investigated in anesthetized rabbits. Twenty four rabbits were randomized into four equal groups: six rabbits in control group received 1 ml ultra-pure water subcutaneously (group 1). Group two received LD50 of venom (4.5 mg/kg). In the third and fourth groups, 5 ml of scorpion antivenom was administrated intravenously simultaneous with venom injection and 60 min following envenomation, respectively. Results of the present study indicate significant decrease in hemodynamic parameters following envenomation in the second group of animals. Venom injection caused edema, myocytolysis, coagulation necrosis, hemorrhage in heart as well as edema, hemorrhage and vascular thrombus in lungs. Although envenomed rabbits presented rises in LDH and TnT but no alteration in CK-MB was observed. Electrocardiogram monitoring of rabbits showed ST elevation and inverted T waves. Simultaneous administration of antivenom and venom prevented entirely the clinical signs, hemodynamic disturbances, markers changes, ECG abnormalities and histopathological damages. Delayed immunotherapy gradually ameliorated clinical signs, hemodynamic disturbances and markers changes related to envenomation. Histopathological evaluation showed slight alterations such as mild myocytolysis in heart and mild edema in lung following delayed immunotherapy. In conclusion, scorpion antivenom administration has preventive, neutralizing and curative properties for M. eupeus scorpion envenomation, if it would be applied at optimum time, dose and route. Copyright © 2011 Elsevier Ltd. All rights reserved.

Culture modulates brain activity during empathy with anger.

PubMed

de Greck, Moritz; Shi, Zhenhao; Wang, Gang; Zuo, Xiangyu; Yang, Xuedong; Wang, Xiaoying; Northoff, Georg; Han, Shihui

2012-02-01

Interdependent cultures (such as the Chinese) and independent cultures (such as the German) differ in their attitude towards harmony that is more valued in interdependent cultures. Interdependent and independent cultures also differ in their appreciation of anger--an emotion that implies the disruption of harmony. The present study investigated if interdependent and independent cultures foster distinct brain activity associated with empathic processing of familiar angry, familiar neutral, and unfamiliar neutral faces. Using functional MRI, we scanned Chinese and German healthy subjects during an intentional empathy task, a control task (the evaluation of skin color), and a baseline condition. The subject groups were matched with regard to age, gender, and education. Behaviorally, Chinese subjects described themselves as significantly more interdependent compared to German subjects. The contrast 'intentional empathy for familiar angry'>'baseline' revealed several regions, including the left inferior frontal cortex, the left supplementary motor area, and the left insula, that showed comparable hemodynamic responses in both groups. However, the left dorsolateral prefrontal cortex had stronger hemodynamic responses in Chinese subjects in the contrast 'intentional empathy for familiar angry'>'baseline'. Germans, in contrast, showed stronger hemodynamic responses in the right temporo-parietal junction, right inferior and superior temporal gyrus, and left middle insula for the same contrast. Hemodynamic responses in the latter three brain regions correlated with interdependences scores over all subjects. Our results suggest that enhanced emotion regulation during empathy with anger in the interdependent lifestyle is mediated by the left dorsolateral prefrontal cortex. Increased tolerance towards the expression of anger in the independent lifestyle, in contrast, is associated with increased activity of the right inferior and superior temporal gyrus and the left middle insula. Copyright © 2011 Elsevier Inc. All rights reserved.

The effects of combined versus selective adrenergic blockade on left ventricular and systemic hemodynamics, myocardial substrate preference, and regional perfusion in conscious dogs with dilated cardiomyopathy.

PubMed

Nikolaidis, Lazaros A; Poornima, Indu; Parikh, Pratik; Magovern, Megan; Shen, You-Tang; Shannon, Richard P

2006-05-02

Given that adverse effects of chronic sympathetic activation are mediated by all three adrenergic receptor subtypes (beta1, beta2, alpha1), we examined the effects of standard doses of carvedilol and metoprolol succinate (metoprolol controlled release/extended release [CR/XL]) on hemodynamics, myocardial metabolism, and regional organ perfusion. Both beta1 selective and combined adrenergic blockade reduce morbidity and mortality in heart failure. Whether there are advantages of one class over the other remains controversial, even in the wake of the Carvedilol Or Metoprolol European Trial (COMET). Similarly, the mechanistic basis for the relative differences is incompletely understood. Thirty-three conscious, chronically instrumented dogs with pacing-induced (240 min(-1) for 4 weeks) dilated cardiomyopathy (DCM) were randomized to carvedilol (25 mg twice daily, Coreg, Glaxo Smith Kline, Research Triangle, North Carolina) or metoprolol succinate (100 mg qd, Toprol XL, Astra Zeneca, Wilmington, Delaware). Left ventricular and systemic hemodynamics, myocardial substrate uptake, and norepinephrine spillover were measured before and after three days of treatment. Regional (renal, hepatic, skeletal muscle) blood flows were measured using neutron-activated microspheres. Both agents had comparable heart rate effects. However, carvedilol-treated dogs showed significantly greater increases in stroke volume and cardiac output and decreases in left ventricular end-diastolic pressure and systemic vascular resistance. Carvedilol increased renal, hepatic, and skeletal muscle blood flow. Carvedilol increased myocardial glucose uptake and suppressed norepinephrine and glucagon. Carvedilol antagonized the response to exogenous norepinephrine to a greater extent than metoprolol CR/XL. At doses inducing comparable heart rate reductions, short-term treatment with carvedilol had superior hemodynamic and metabolic effects compared with metoprolol CR/XL. These data suggest important advantages of blocking all three adrenergic receptor subtypes in DCM.

Effects of 12 days exposure to simulated microgravity on central circulatory hemodynamics in the rhesus monkey

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Koenig, S. C.; Krotov, V. P.; Fanton, J. W.; Korolkov, V. I.; Trambovetsky, E. V.; Ewert, D. L.; Truzhennikov, A.; Latham, R. D.

1998-01-01

Central circulatory hemodynamic responses were measured before and during the initial 9 days of a 12-day 10 degrees head-down tilt (HDT) in 4 flight-sized juvenile rhesus monkeys who were surgically instrumented with a variety of intrathoracic catheters and blood flow sensors to assess the effects of simulated microgravity on central circulatory hemodynamics. Each subject underwent measurements of aortic and left ventricular pressures, and aortic flow before and during HDT as well as during a passive head-up postural test before and after HDT. Heart rate, stroke volume, cardiac output, and left ventricular end-diastolic pressure were measured, and dP/dt and left ventricular elastance was calculated from hemodynamic measurements. The postural test consisted of 5 min of supine baseline control followed by 5 minutes of 90 degrees upright tilt (HUT). Heart rate, stroke volume, cardiac output, and left ventricular end-diastolic pressure showed no consistent alterations during HDT. Left ventricular elastance was reduced in all animals throughout HDT, indicating that cardiac compliance was increased. HDT did not consistently alter left ventricular +dP/dt, indicating no change in cardiac contractility. Heart rate during the post-HDT HUT postural test was elevated compared to pre-HDT while post-HDT cardiac output was decreased by 52% as a result of a 54% reduction in stroke volume throughout HUT. Results from this study using an instrumented rhesus monkey suggest that exposure to microgravity may increase ventricular compliance without alternating cardiac contractility. Our project supported the notion that an invasively-instrumented animal model should be viable for use in spaceflight cardiovascular experiments to assess potential changes in myocardial function and cardiac compliance.

Prevention of altered hemodynamics after spinal anesthesia: A comparison of volume preloading with tetrastarch, succinylated gelatin and ringer lactate solution for the patients undergoing lower segment caesarean section

PubMed Central

Mitra, Tapobrata; Das, Anjan; Majumdar, Saikat; Bhattacharyya, Tapas; Mandal, Rahul Deb; Hajra, Bimal Kumar

2014-01-01

Background: Spinal anesthesia has replaced general anesthesia in obstetric practice. Hemodynamic instability is a common, but preventable complication of spinal anesthesia. Preloading the circulation with intravenous fluids is considered a safe and effective method of preventing hypotension following spinal anesthesia. We had conducted a study to compare the hemodynamic stability after volume preloading with either Ringer's lactate (RL) or tetrastarch hydroxyethyl starch (HES) or succinylated gelatin (SG) in the patients undergoing cesarean section under spinal anesthesia. Materials and Methods: It was a prospective, double-blinded and randomized controlled study. Ninety six ASA-I healthy, nonlaboring parturients were randomly divided in 3 groups HES, SG, RL (n = 32 each) and received 10 ml/kg HES 130/0.4; 10 ml/kg SG (4% modified fluid gelatin) and 20 ml/kg RL respectively prior to SA scheduled for cesarean section. Heart rate, blood pressure (BP), oxygen saturation was measured. Results: The fall in systolic blood pressure (SBP) (<100 mm Hg) noted among 5 (15.63%), 12 (37.5%) and 14 (43.75%) parturients in groups HES, SG, RL respectively. Vasopressor (phenylephrine) was used to treat hypotension when SBP <90 mm Hg. Both the results and APGAR scores were comparable in all the groups. Lower preloading volume and less intra-operative vasopressor requirement was noted in HES group for maintaining BP though it has no clinical significance. Conclusion: RL which is cheap, physiological and widely available crystalloid can preload effectively and maintain hemodynamic stability well in cesarean section and any remnant hypotension can easily be manageable with vasopressor. PMID:25422601

Sodium Tanshinone IIA Sulfonate Improves Hemodynamic Parameters, Cytokine Release, and Multi-Organ Damage in Endotoxemia Rabbits.

PubMed

Ma, Shaolei; Wang, Xian; Wang, Yujie; Zuo, Xiangrong

2018-05-08

BACKGROUND The aim of this study was to evaluate the protective effects of sodium tanshinone IIA sulfonate (STS) on hemodynamic parameters, cytokine release, and multiple organ damage in an animal model of lipopolysaccharide (LPS)-induced endotoxemia. MATERIAL AND METHODS Twenty-four rabbits were randomly divided into 3 groups: control (n=8), LPS (n=8), and STS pretreatment + LPS (n=8) groups. With arterial invasive monitoring, hemodynamic variables were observed at 30 min before and at 0, 10, 20, 30, 60, 120, 180, 240, and 300 min after LPS injection. Circulatory inflammatory cytokines, including tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10), and relevant biochemical markers, including arterial partial pressure of oxygen (PaO2), plasma cardiac troponin I (cTnI), alanine aminotransferase (ALT), and creatinine (Cr), were measured at each time point. At the end of the experiment, all rabbits were sacrificed; histopathological examination of the heart, lung, liver, and kidney tissue was performed and organ injury was semi-quantitatively scored for each organ. RESULTS Mean arterial pressure (MAP) and heart rate (HR) significantly decreased within 30 min and again after 120 min following LPS injection. However, STS pretreatment gradually normalized MAP and HR after 120 min following LPS injection. In addition, STS ameliorated LPS-induced decrease of PaO2, LPS-induced increase of TNF-α, cTnI, and ALT, and enhanced LPS-induced increase of IL-10. Moreover, STS reduced heart, lung, and liver histopathologic injury. CONCLUSIONS STS can significantly stabilize LPS-induced hemodynamic deterioration, regulate inflammatory cytokine secretion, and protect heart, lung, and liver in rabbits.

A review of the hemodynamic effects of external leg and lower body compression.

PubMed

Helmi, M; Gommers, D; Groeneveld, A B J

2014-03-01

External leg and lower body compression (ELC) has been used for decades in the prevention of deep vein thrombosis and the treatment of leg ischemia. Because of systemic effects, the methods have regained interest in anesthesia, surgery and critical care. This review intends to summarize hemodynamic effects and their mechanisms. Compilation of relevant literature published in English as full paper and retrieved from Medline. By compressing veins, venous stasis is diminished and venous return and arterial blood flow are increased. ELC has been suggested to improve systemic hemodynamics, in different clinical settings, such as postural hypotension, anesthesia, surgery, shock, cardiopulmonary resuscitation and mechanical ventilation. However, the hemodynamic alterations depend upon the magnitude, extent, cycle, duration and thus the modality of ELC, when applied in a static or intermittent fashion (by pneumatic inflation), respectively. ELC may help future research and optimizing treatment of hemodynamically unstable, surgical or critically ill patients, independent of plasma volume expansion.

Hemodynamic deterioration precedes onset of ventricular tachyarrhythmia after Heartmate II implantation.

PubMed

Yaksh, Ameeta; Kik, Charles; Knops, Paul; Zwiers, Korinne; van Ettinger, Maarten J B; Manintveld, Olivier C; de Wijs, Marcel C J; van der Kemp, Peter; Bogers, Ad J J C; de Groot, Natasja M S

2016-07-08

Early postoperative ventricular tachyarrhythmia (PoVT) after left ventricular assist device (LVAD) implantation are common and associated with higher mortality-rates. At present, there is no data on initiation of these PoVT and the role of alterations in cardiac hemodynamics. A LVAD was implanted in a patient with end-stage heart failure due to a ischemic cardiomyopathy. Alterations in cardiac rhythm and hemodynamics preceding PoVT-episodes during the first five postoperative days were examined by using continuous recordings of cardiac rhythm and various hemodynamic parameters. All PoVT (N=120) were monomorphic, most often preceded by short-long-short-sequences or regular SR and initiated by ventricular runs. Prior to PoVT, mean arterial pressure decreased; heart rate and ST-segments deviations increased. PoVT are caused by different underlying electrophysiological mechanisms. Yet, they are all monomorphic and preceded by hemodynamic deterioration due to myocardial ischemia.

Hemodynamic deterioration after aortic valve replacement in a patient with mixed systemic amyloidosis.

PubMed

Seki, Tatsuya; Hattori, Atsuo; Yoshida, Toshihito

2017-08-01

We report a case of hemodynamic deterioration after aortic valve replacement in a patient with mixed systemic amyloidosis. A 77-year-old male with severe aortic valve stenosis and 19 years hemodialysis underwent aortic valve replacement. Postoperatively, the patient died of hemodynamic deterioration. Autopsy findings showed massive, whole-body edema and mixed systemic amyloidosis (dialysis-related and AA amyloidosis). Clinical and autopsy findings implied that hemodynamic deterioration was caused by increased vascular permeability. The amyloid deposit to the vessel causes inflammatory changes and increases vascular permeability. Mixed systemic amyloidosis occurs very rarely and could increases vascular permeability even more than each single type of amyloidosis. Systemic amyloidosis may be a risk factor for hemodynamic deterioration after cardiac surgery. Patients with longtime hemodialysis and a history associated with dialysis-related amyloidosis would have at least single systemic amyloidosis, which should be considered a contraindication to cardiac surgery with cardiopulmonary bypass.

The changes of cerebral hemodynamics during ketamine induced anesthesia in a rat model.

PubMed

Bae, Jayyoung; Shin, Teo J; Kim, Seonghyun; Choi, Dong-Hyuk; Cho, Dongrae; Ham, Jinsil; Manca, Marco; Jeong, Seongwook; Lee, Boreom; Kim, Jae G

2018-05-25

Current electroencephalogram (EEG) based-consciousness monitoring technique is vulnerable to specific clinical conditions (eg, epilepsy and dementia). However, hemodynamics is the most fundamental and well-preserved parameter to evaluate, even under severe clinical situations. In this study, we applied near-infrared spectroscopy (NIRS) system to monitor hemodynamic change during ketamine-induced anesthesia to find its correlation with the level of consciousness. Oxy-hemoglobin (OHb) and deoxy-hemoglobin concentration levels were continuously acquired throughout the experiment, and the reflectance ratio between 730 and 850 nm was calculated to quantify the hemodynamic changes. The results showed double peaks of OHb concentration change during ketamine anesthesia, which seems to be closely related to the consciousness state of the rat. This finding suggests the possibility of NIRS based-hemodynamic monitoring as a supplementary parameter for consciousness monitoring, compensating drawbacks of EEG signal based monitoring. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Effect of different transpulmonary pressures guided mechanical ventilation on respiratory and hemodynamics of patients with ARDS: a prospective randomized controlled trial].

PubMed

Li, Jianqiu; Luo, Zhihui; Li, Xiaolei; Huang, Zhongyi; Han, Jie; Li, Zifeng; Zhou, Zhaoxiong; Chen, Houwang

2017-01-01

To assess the effect of different transpulmonary pressures (Ptp) guided mechanical ventilation (MV) on respiratory function and hemodynamics parameters of patients with acute respiratory distress syndrome (ARDS), and to find out a more optimized Ptp. A prospective randomized controlled trial (RCT) was conducted. The ventilated patients with ARDS admitted to Department of Critical Care Medicine (ICU) of Shenzhen Shajing Affiliated Hospital of Guangzhou Medical University and Department of Emergency and Critical Care Medicine (EICU) of Shenzhen Hospital of South Medical University from February 2013 to August 2016 were enrolled. According to random number table method, all patients were divided into control group and observation group. The patients in observation group was subdivided into three subgroups according to the different setting of Ptp, namely Ptp 10, 15, 20 cmH 2 O (1 cmH 2 O = 0.098 kPa) subgroups. The patients in all groups received standard treatment in accordance with the international guidelines for ARDS. The patients in control group were ventilated by guidance of ARDSNet, and the patients in observation group were ventilated by guidance of different Ptp. After setting different Ptp at 1, 24, 48 hours in the process of MV, respiratory function parameters of patients in all groups were determined. The hemodynamic parameters were determined by using pulse indicating continuous cardiac output (PiCCO) technology. The duration of MV, length of ICU stay and 28-day mortality were recorded. A total of 67 patients with ARDS were enrolled, among whom 2 patients died within 48 hours, and 1 case was lost to follow-up. Finally, 64 patients completed the study, 43 patients in observation group, and 21 in control group. There were no significant differences in gender composition, age, oxygenation index (PaO 2 /FiO 2 ) within 4 hours after hospital admission and acute physiology and chronic health evaluation II (APACHE II) score between the two groups, which showed the baseline was equivalent and comparable. The respiratory function and hemodynamic parameters showed no obvious change in control group at different time points of MV; but with the extension of ventilation, the respiratory function was improved significantly in observation group, and the gradually rising of Ptp had obvious adverse effects on hemodynamics parameters. Compared with control group, at 48 hours of ventilation after setting Ptp, the respiratory function in Ptp 20 cmH 2 O subgroup was improved significantly, PaO 2 /FiO 2 , arterial partial pressure of carbon dioxide (PaCO 2 ), positive end-expiratory pressure (PEEP), airway platform pressure (Pplat), and lung compliance (Cst) were significantly increased [PaO 2 /FiO 2 (mmHg, 1 mmHg = 0.133 kPa): 220.9±30.8 vs. 178.5±42.9, PaCO 2 (mmHg): 55.1±7.6 vs. 38.6±4.8, PEEP (cmH 2 O): 24.7±4.8 vs. 6.6±2.2, Pplat (cmH 2 O): 34.4±3.7 vs. 20.7±3.5, Cst (mL/cmH 2 O): 23.8±3.6 vs. 13.1±4.6; all P < 0.05], and extravascular lung water index (ELWI) was significantly decreased (mL/kg: 6.8±1.7 vs. 10.8±2.6, P < 0.05), but mean artery pressure (MAP), cardiac index (CI), global end-diastolic volume index (GEDVI) such as hemodynamics parameters were also significantly reduced [MAP (mmHg): 58.8±6.7 vs. 69.7±4.7, CI (mL×s -1 ×m -2 ): 46.7±23.3 vs. 73.3±30.0, GEDVI (mL/m 2 ): 633.2±45.2 vs. 702.6±55.7; all P < 0.05]; the PaO 2 /FiO 2 , PEEP, Pplat, and Cst in Ptp 10 cmH 2 O subgroup were significantly increased [PaO 2 /FiO 2 (mmHg): 183.4±45.5 vs. 178.5±42.9, PEEP (cmH 2 O): 14.4±3.6 vs. 6.6±2.2, Pplat (cmH 2 O): 25.7±5.6 vs. 20.7±3.5, Cst (mL/cmH 2 O): 16.2±4.3 vs. 13.1±4.6; all P < 0.05], and ELWI was significantly reduced (mL/kg: 8.7±1.8 vs. 10.8±2.6, P < 0.05), but the MAP, CI and GEDVI showed no significant difference [MAP (mmHg): 65.8±4.6 vs. 69.7±4.7, CI (mL×s -1 ×m -2 ): 65.0±35.0 vs. 73.3±30.0, GEDVI (mL/m 2 ): 706.7±54.4 vs. 702.6±55.7; all P > 0.05]. The above illustrated that 10 cmH 2 O Ptp could act as the same as 20 cmH 2 O did to improve oxygenation and respiratory function, but had no obvious effect on hemodynamics. Compared with control group, the duration of MV and the length of ICU stay showed no significant differences in Ptp 10 cmH 2 O and 15 cmH 2 O subgroups, but those in 20 cmH 2 O subgroup were significantly shortened [duration of MV (days): 95.5±21.5 vs. 130.8±23.6, length of ICU stay (days): 8.1±2.2 vs. 12.8±2.8, both P > 0.05]. There was no significant difference in 28-day mortality among the groups. MV guided by Ptp of 10 cmH 2 O could improve oxygenation and respiratory mechanics, while has less hemodynamic influence. It was a safe and effective cardiopulmonary protection ventilation method.

Prefrontal Hemodynamic Changes Associated with Subjective Sense of Occlusal Discomfort

PubMed Central

Kobayashi, Goh; Hayama, Rika; Ikuta, Ryuhei; Onozouka, Minoru; Wake, Hiroyuki; Shimada, Atsushi; Shibuya, Tomoaki; Tamaki, Katsushi

2015-01-01

We used functional near-infrared spectroscopy to measure prefrontal brain activity accompanying the physical sensation of oral discomfort that arose when healthy young-adult volunteers performed a grinding motion with mild occlusal elevation (96 μm). We simultaneously evaluated various forms of occlusal discomfort using the visual analogue scale (VAS) and hemodynamic responses to identify the specific prefrontal activity that occurs with increased occlusal discomfort. The Oxy-Hb responses of selected channels in the bilateral frontopolar and dorsolateral prefrontal cortices increased in participants who reported increased severity of occlusal discomfort, while they decreased in those who reported no change or decreased occlusal discomfort during grinding. Moreover, the cumulative values of Oxy-Hb response in some of these channels were statistically significant predictive factors for the VAS scores. A generalized linear model analysis of Oxy-Hb signals in a group of participants who reported increased discomfort further indicated significant cerebral activation in the right frontopolar and dorsolateral prefrontal cortices that overlapped with the results of correlation analyses. Our results suggest that the increased hemodynamic responses in the prefrontal area reflect the top-down control of attention and/or self-regulation against the uncomfortable somatosensory input, which could be a possible marker to detect the subjective sense of occlusal discomfort. PMID:26090407

Patent Ductus Arteriosus in Preterm Infants: Do We Have the Right Answers?

PubMed Central

Nasef, Nehad; Nour, Islam

2013-01-01

Patent ductus arteriosus (PDA) is a common clinical condition in preterm infants. Preterm newborns with PDA are at greater risk for several morbidities, including higher rates of bronchopulmonary dysplasia (BPD), decreased perfusion of vital organs, and mortality. Therefore, cyclooxygenase (COX) inhibitors and surgical interventions for ligation of PDA are widely used. However, these interventions were reported to be associated with side effects. In the absence of clear restricted rules for application of these interventions, different strategies are adopted by neonatologists. Three different approaches have been investigated including prophylactic treatment shortly after birth irrespective of the state of PDA, presymptomatic treatment using echocardiography at variable postnatal ages to select infants for treatment prior to the duct becoming clinically significant, and symptomatic treatment once PDA becomes clinically apparent or hemodynamically significant. Future appropriately designed randomized controlled trials (RCTs) to refine selection of patients for medical and surgical treatments should be conducted. Waiting for new evidence, it seems wise to employ available clinical and echocardiographic parameters of a hemodynamically significant (HS) PDA to select patients who are candidates for medical treatment. Surgical ligation of PDA could be used as a back-up tool for those patients who failed medical treatment and continued to have hemodynamic compromise. PMID:24455715

Different Brain Responses to Pain and Its Expectation in the Dental Chair.

PubMed

Racek, A J; Hu, X; Nascimento, T D; Bender, M C; Khatib, L; Chiego, D; Holland, G R; Bauer, P; McDonald, N; Ellwood, R P; DaSilva, A F

2015-07-01

A dental appointment commonly prompts fear of a painful experience, yet we have never fully understood how our brains react to the expectation of imminent tooth pain once in a dental chair. In our study, 21 patients with hypersensitive teeth were tested using nonpainful and painful stimuli in a clinical setting. Subjects were tested in a dental chair using functional near-infrared spectroscopy to measure cortical activity during a stepwise cold stimulation of a hypersensitive tooth, as well as nonpainful control stimulation on the same tooth. Patients' sensory-discriminative and emotional-cognitive cortical regions were studied through the transition of a neutral to a painful stimulation. In the putative somatosensory cortex contralateral to the stimulus, 2 well-defined hemodynamic peaks were detected in the homuncular orofacial region: the first peak during the nonpainful phase and a second peak after the pain threshold was reached. Moreover, in the upper-left and lower-right prefrontal cortices, there was a significant active hemodynamic response in only the first phase, before the pain. Subsequently, the same prefrontal cortical areas deactivated after a painful experience had been reached. Our study indicates for the first time that pain perception and expectation elicit different hemodynamic cortical responses in a dental clinical setting. © International & American Associations for Dental Research 2015.

Simultaneous functional near-infrared brain imaging and event-related potential studies of Stroop effect

NASA Astrophysics Data System (ADS)

Zhai, Jiahuan; Li, Ting; Zhang, Zhongxing; Gong, Hui

2009-02-01

Functional near-infrared brain imaging (fNIRI) and event-related potential (ERP) were used simultaneous to detect the prefrontal cortex (PFC) which is considered to execute cognitive control of the subjects while performing the Chinese characters color-word matching Stroop task with event-related design. The fNIRI instrument is a portable system operating at three wavelengths (735nm & 805nm &850nm) with continuous-wave. The event-related potentials were acquired by Neuroscan system. The locations of optodes corresponding to the electrodes were defined four areas symmetrically. In nine native Chinese-speaking fit volunteers, fNIRI measured the hemodynamic parameters (involving oxy-/deoxy- hemoglobin) changes when the characteristic waveforms (N500/P600) were recorded by ERP. The interference effect was obvious as a longer reaction time for incongruent than congruent and neutral stimulus. The responses of hemodynamic and electrophysiology were also stronger during incongruent compared to congruent and neutral trials, and these results are similar to those obtained with fNIRI or ERP separately. There are high correlations, even linear relationship, in the two kinds of signals. In conclusion, the multi-modality approach combining of fNIRI and ERP is feasible and could obtain more cognitive function information with hemodynamic and electrophysiology signals. It also provides a perspective to prove the neurovascular coupling mechanism.

Hypertrophic response to hemodynamic overload: role of load vs. renin-angiotensin system activation

NASA Technical Reports Server (NTRS)

Koide, M.; Carabello, B. A.; Conrad, C. C.; Buckley, J. M.; DeFreyte, G.; Barnes, M.; Tomanek, R. J.; Wei, C. C.; Dell'Italia, L. J.; Cooper, G. 4th;

Hemodynamic changes in post-suspension rats during gradual hemorrhage

NASA Astrophysics Data System (ADS)

Vinogradova, O. L.; Borovik, A. S.; Tsvirkoun, D. V.; Tarasova, O. S.

2005-08-01

In urethane-anasthetized rats the effects of 2-week tail suspension upon the hemodynamic changes during simulated orthostatism and during loss of blood were studied. Baseline values of mean arterial pressure (MAP) and pulse interval (PI) did not differ in cage control (C) and post-suspension rats (TS). In both groups 45o head-up tilt resulted in prominent decline of MAP. In C group this effect was followed by the compensatory phase, which was virtually lost in TS group. No significant postural changes of PI were observed. Gradual hemorrhage (30% blood loss during 30 min) resulted in similar MAP drop in C and TS (up to 40% of baseline level). Along with that, PI increase was less prominent in TS (25%) compared to C (60%) indicating higher resistance of the heart to hypovolemia after suspension.

Control of respiration-driven retrograde flow in the subdiaphragmatic venous return of the Fontan circulation

PubMed Central

Vukicevic, M; Conover, T; Jaeggli, M; Zhou, J; Pennati, G; Hsia, TY; Figliola, RS

2014-01-01

Respiration influences the subdiaphragmatic venous return in the total cavopulmonary connection (TCPC) of the Fontan circulation whereby both the inferior vena cava (IVC) and hepatic vein flows can experience retrograde motion. Controlling retrograde flows could improve patient outcomes. Using a patient-specific model within a Fontan mock circulatory system with respiration, we inserted a valve into the IVC to examine its effects on local hemodynamics while varying retrograde volumes by changing vascular impedances. A bovine valved conduit reduced IVC retrograde flow to within 3% of antegrade flow in all cases. The valve closed only under conditions supporting retrograde flow and its effects on local hemodynamics increased with larger retrograde volume. Liver and TCPC pressures improved only while the valve leaflets were closed while cycle-averaged pressures improved only slightly (italic>1 mm Hg). Increased pulmonary vascular resistance raised mean circulation pressures but the valve functioned and cardiac output improved and stabilized. Power loss across the TCPC improved by 12–15% (pbold>0.05) with a valve. The effectiveness of valve therapy is dependent on patient vascular impedance. PMID:24814833

Right Ventricular Hemodynamics in Patients with Pulmonary Hypertension

NASA Astrophysics Data System (ADS)

Browning, James; Fenster, Brett; Hertzberg, Jean; Schroeder, Joyce

2012-11-01

Recent advances in cardiac magnetic resonance imaging (CMR) have allowed for characterization of blood flow in the right ventricle (RV), including calculation of vorticity and circulation, and qualitative visual assessment of coherent flow patterns. In this study, we investigate qualitative and quantitative differences in right ventricular hemodynamics between subjects with pulmonary hypertension (PH) and normal controls. Fifteen (15) PH subjects and 10 age-matched controls underwent same day 3D time resolved CMR and echocardiography. Echocardiography was used to determine right ventricular diastolic function as well as pulmonary artery systolic pressure (PASP). Velocity vectors, vorticity vectors, and streamlines in the RV were visualized in Paraview and total RV Early (E) and Atrial (A) wave diastolic vorticity was quantified. Visualizations of blood flow in the RV are presented for PH and normal subjects. The hypothesis that PH subjects exhibit different RV vorticity levels than normals during diastole is tested and the relationship between RV vorticity and PASP is explored. The mechanics of RV vortex formation are discussed within the context of pulmonary arterial pressure and right ventricular diastolic function coincident with PH.

Acupuncture therapy improves vascular hemodynamics and stiffness in middle-age hypertensive individuals.

PubMed

Terenteva, Nina; Chernykh, Oksana; Sanchez-Gonzalez, Marcos A; Wong, Alexei

2018-02-01

Acupuncture (ACU) is becoming a more common practice among hypertensive individuals. However, the reported therapeutic effects of ACU in lowering brachial blood pressure (BP) are ambiguous. Therefore, evaluating more sensitive markers of arterial functioning might unveil the protective effects of ACU on hypertension. We examined the effects of an 8-week ACU therapy intervention on vascular hemodynamics and stiffness in middle-age hypertensive individuals. Participants were randomly assigned to either ACU (n = 23) or a control group (n = 22). Brachial and aortic BP, wave reflection (AIx) and arterial stiffness (SI) were measured before and after 8 weeks. There was a significant group x time interaction (P < 0.05) for brachial and aortic BP, AIx and SI which significantly decreased (P < 0.05) following ACU but not after control. ACU led to reductions in brachial and aortic BP, wave reflection and arterial stiffness in middle-age hypertensive individuals. ACU might be effective in the prevention and treatment of hypertension. Copyright © 2017 Elsevier Ltd. All rights reserved.

Predictors of in-hospital mortality in a cohort of elderly Egyptian patients with acute upper gastrointestinal bleeding.

PubMed

Elsebaey, Mohamed A; Elashry, Heba; Elbedewy, Tamer A; Elhadidy, Ahmed A; Esheba, Noha E; Ezat, Sherif; Negm, Manal Saad; Abo-Amer, Yousry Esam-Eldin; Abgeegy, Mohamed El; Elsergany, Heba Fadl; Mansour, Loai; Abd-Elsalam, Sherief

2018-04-01

Acute upper gastrointestinal bleeding (UGIB) affects large number of elderly with high rates of morbidity and mortality. Early identification and management of the factors predicting in-hospital mortality might decrease mortality. This study was conducted to identify the causes of acute UGIB and the predictors of in-hospital mortality in elderly Egyptian patients.286 elderly patients with acute UGIB were divided into: bleeding variceal group (161 patients) and bleeding nonvariceal group (125 patients). Patients' monitoring was done during hospitalization to identify the risk factors that might predict in-hospital mortality in elderly.Variceal bleeding was the most common cause of acute UGIB in elderly Egyptian patients. In-hospital mortality rate was 8.74%. Increasing age, hemodynamic instability at presentation, co-morbidities (especially liver cirrhosis associated with other co-morbidity) and failure to control bleeding were the predictors of in-hospital mortality.Increasing age, hemodynamic instability at presentation, co-morbidities (especially liver cirrhosis associated with other co-morbidity) and failure to control bleeding should be considered when triaging those patients for immediate resuscitation, close observation, and early treatment.

Cellular and molecular mechanisms regulating vascular tone. Part 1: basic mechanisms controlling cytosolic Ca2+ concentration and the Ca2+-dependent regulation of vascular tone.

PubMed

Akata, Takashi

2007-01-01

General anesthetics cause hemodynamic instability and alter blood flow to various organs. There is mounting evidence that most general anesthetics, at clinical concentrations, influence a wide variety of cellular and molecular mechanisms regulating the contractile state of vascular smooth muscle cells (i.e., vascular tone). In addition, in current anesthetic practice, various types of vasoactive agents are often used to control vascular reactivity and to sustain tissue blood flow in high-risk surgical patients with impaired vital organ function and/or hemodynamic instability. Understanding the physiological mechanisms involved in the regulation of vascular tone thus would be beneficial for anesthesiologists. This review, in two parts, provides an overview of current knowledge about the cellular and molecular mechanisms regulating vascular tone-i.e., targets for general anesthetics, as well as for vasoactive drugs that are used in intraoperative circulatory management. This first part of the two-part review focuses on basic mechanisms regulating cytosolic Ca2+ concentration and the Ca2+-dependent regulation of vascular tone.

Hemodynamic analysis of patients in intensive care unit based on diffuse optical spectroscopic imaging system

NASA Astrophysics Data System (ADS)

Hsieh, Yao-Sheng; Wang, Chun-Yang; Ling, Yo-Wei; Chuang, Ming-Lung; Chuang, Ching-Cheng; Tsai, Jui-che; Lu, Chih-Wei; Sun, Chia-Wei

2010-02-01

Diffuse optical spectroscopic imaging (DOSI) is a technique to assess the spatial variation in absorption and scattering properties of the biological tissues and provides the monitoring of changes in concentrations of oxy-hemoglobin and deoxy-hemoglobin. In our preliminary study, the temporal tracings of hemodynamic oxygenation are measured with DOSI and venous occlusion test (VOT) from normal subjects, patients with heart failure and patients with sepsis in intensive care unit (ICU). In experiments, the obvious differences of hemodynamic signals can be observed among the three groups. The physiological relevance of VOT hemodynamics with respect to diseases is also discussed in this paper.

Shed a light in fatigue detection with near-infrared spectroscopy during long-lasting driving

NASA Astrophysics Data System (ADS)

Gao, Yuan; Pan, Boan; Li, Kai; Li, Ting

2016-03-01

Fatigue driving is one of the leading roles to induce traffic accident and injury, which urgently desires a novel technique to monitor the fatigue level at driving. Functional near infrared spectroscopy (fNIRS) is capable of noninvasive monitoring brain-activities-related hemodynamic responses. Here, we developed a fINRS imager and setup a classic psychological experiment to trigger visual divided attention which varied responding to driving fatigue, and attempted to record the drive-fatigue-level correlated hemodynamic response in the prefrontal cortex. 7 volunteers were recruited to take 7 hours driving and the experimental test was repeated every 1 hour and 8 times in total. The hemodynamic response were extracted and graphed with pseudo image. The analysis on the relationship between the fNIRS-measured hemodynamic response and fatigue level finally displayed that the oxyhemoglobin concentration in one channel of left prefrontal lobe increased with driving duration in significant correlation. And the spatial pattern of hemodynamic response in the prefrontal lobe varied with driving duration as well. The findings indicated the potential of fNIRSmeasured hemodynamic index in some sensitive spot of prefrontal lobe as a driving fatigue indicator and the promising use of fNIRS in traffic safety field.

The effect of magneto-treated blood autotransfusion on central hemodynamic values and cerebral circulation in patients with essential hypertension.

PubMed

Alizade, Ilgar G; Karayeva, Nigar T

2002-05-01

The work was carried out to study the effect of magneto-treated blood autotransfusion on the values of central and cerebral hemodynamics in patients with essential hypertension. Sixty-six patients with stage II essential hypertension aged 31-60 years who underwent magneto-treated blood autotransfusion were evaluated and treated, at the Cardiology Department, Hospital of Ministry of Internal Affairs of the Azerbaijan Republic, over a period of 8 years. The diagnosis was based on clinical examination and generally accepted criteria of essential hypertension stages proposed in 1978 by the World Health Organization. Sixty-six patients with stage II essential hypertension with stable drop in blood pressure, simultaneously showed a positive clinical effect. Central hemodynamic changes in the process of magneto-treated blood autotransfusion were different and depended on the initial state of circulation. High clinical effect showed the patients with hyperkinetic type of hemodynamics. Their blood pressure were significantly lower than the patients with hypokinetic type of circulation. Rheoencephalographic study demonstrated that magneto-treated blood autotransfusion possessed insignificant effect on cerebral hemodynamics, mainly expressed by the reduction of arterial blood flow tension in the patients with hypokinetic type of hemodynamics.

The relationship between dorsolateral prefrontal activation and speech performance-based social anxiety using functional near infrared spectroscopy.

PubMed

Glassman, Lisa H; Kuster, Anootnara T; Shaw, Jena A; Forman, Evan M; Izzetoglu, Meltem; Matteucci, Alyssa; Herbert, James D

2017-06-01

Functional near-infrared (fNIR) spectroscopy is a promising new technology that has demonstrated utility in the study of normal human cognition. We utilized fNIR spectroscopy to examine the effect of social anxiety and performance on hemodynamic activity in the dorsolateral prefrontal cortex (DLPFC). Socially phobic participants and non-clinical participants with varying levels of social anxiety completed a public speaking task in front of a small virtual audience while the DLPFC was being monitored by the fNIR device. The relationship between anxiety and both blood volume (BV) and deoxygenated hemoglobin (Hb) varied significantly as a function of speech performance, such that individuals with low social anxiety who performed well showed an increase in DLPFC activation relative to those who did not perform well. This result suggests that effortful thinking and/or efficient top-down inhibitory control may have been required to complete an impromptu speech task with good performance. In contrast, good performers who were highly socially anxious showed lower DLPFC activation relative to good performers who were low in social anxiety, suggesting autopilot thinking or less-effortful thinking. In poor performers, slight increases in DLPFC activation were observed from low to highly anxious individuals, which may reflect a shift from effortless thinking to heightened self-focused attention. Heightened self-focused attention, poor inhibitory control resulting in excessive fear or anxiety, or low motivation may lower performance. These results suggest that there can be different underlying mechanisms in the brain that affect the level of speech performance in individuals with varying degrees of social anxiety. This study highlights the utility of the fNIR device in the assessment of changes in DLPFC in response to exposure to realistic phobic stimuli, and further supports the potential utility of this technology in the study of the neurophysiology of anxiety disorders.

Cardioprotective and Metabolomic Profiling of Selected Medicinal Plants against Oxidative Stress

PubMed Central

Afsheen, Nadia; Jahan, Nazish; Ijaz, Misbah; Manzoor, Asad; Khan, Khalid Mahmood; Hina, Saman

2018-01-01

In this research work, the antioxidant and metabolomic profiling of seven selected medicinally important herbs including Rauvolfia serpentina, Terminalia arjuna, Coriandrum sativum, Elettaria cardamom, Piper nigrum, Allium sativum, and Crataegus oxyacantha was performed. The in vivo cardioprotective potential of these medicinal plants was evaluated against surgically induced oxidative stress through left anterior descending coronary artery ligation (LADCA) in dogs. The antioxidant profiling of these plants was done through DPPH and DNA protection assay. The C. oxyacantha and T. arjuna showed maximum antioxidant potential, while the E. cardamom showed poor antioxidative strength even at its high concentration. Different concentrations of extracts of the said plants exhibited the protection of plasmid DNA against H2O2 damage as compared to the plasmid DNA merely treated with H2O2. The metabolomic profiling through LC-MS analysis of these antioxidants revealed the presence of active secondary metabolites responsible for their antioxidant potential. During in vivo analysis, blood samples of all treatment groups were drawn at different time intervals to analyze the cardiac and hemodynamic parameters. The results depicted that the group pretreated with HC4 significantly sustained the level of CK-MB, SGOT, and LDH as well as hemodynamic parameters near to normal. The histopathological examination also confirmed the cardioprotective potential of HC4. Thus, the HC4 being safe and inexpensive cardioprotective herbal combination could be considered as an alternate of synthetic drugs. PMID:29576858

Eccentricity mapping of the human visual cortex to evaluate temporal dynamics of functional T1ρ mapping.

PubMed

Heo, Hye-Young; Wemmie, John A; Johnson, Casey P; Thedens, Daniel R; Magnotta, Vincent A

2015-07-01

Recent experiments suggest that T1 relaxation in the rotating frame (T(1ρ)) is sensitive to metabolism and can detect localized activity-dependent changes in the human visual cortex. Current functional magnetic resonance imaging (fMRI) methods have poor temporal resolution due to delays in the hemodynamic response resulting from neurovascular coupling. Because T(1ρ) is sensitive to factors that can be derived from tissue metabolism, such as pH and glucose concentration via proton exchange, we hypothesized that activity-evoked T(1ρ) changes in visual cortex may occur before the hemodynamic response measured by blood oxygenation level-dependent (BOLD) and arterial spin labeling (ASL) contrast. To test this hypothesis, functional imaging was performed using T(1ρ), BOLD, and ASL in human participants viewing an expanding ring stimulus. We calculated eccentricity phase maps across the occipital cortex for each functional signal and compared the temporal dynamics of T(1ρ) versus BOLD and ASL. The results suggest that T(1ρ) changes precede changes in the two blood flow-dependent measures. These observations indicate that T(1ρ) detects a signal distinct from traditional fMRI contrast methods. In addition, these findings support previous evidence that T(1ρ) is sensitive to factors other than blood flow, volume, or oxygenation. Furthermore, they suggest that tissue metabolism may be driving activity-evoked T(1ρ) changes.

Rocuronium versus vecuronium during fentanyl induction in patients undergoing coronary artery surgery.

PubMed

Smith, C E; Botero, C; Holbrook, C; Pinchak, A C; Hagen, J F

1999-10-01

To evaluate the neuromuscular, ventilatory, and cardiovascular effects of rocuronium and vecuronium. Randomized, prospective, blinded study. Tertiary care teaching center, single institution. Patients undergoing elective coronary artery bypass graft procedure. Patients received rocuronium, 1.0 mg/kg (n = 17), or vecuronium, 0.15 mg/kg (n = 15), during fentanyl induction of anesthesia. Measures consisted of time to visual loss of orbicularis oculi twitches in response to facial nerve stimulation, ease of mask ventilation, hemodynamics, need for vasoactive drugs, and tracheal intubating conditions. Median time to twitch loss was faster (p < 0.05) after rocuronium (60 s) than after vecuronium (>84 s). Within 45 seconds, only 3 of 17 patients in the rocuronium group had moderate-to-severe difficulty with mask ventilation versus 12 of 15 patients in the vecuronium group (p < 0.05). Tracheal intubating conditions were excellent in all patients after rocuronium. In the vecuronium group, intubating conditions were excellent in 46%, good in 27%, and poor in 27% (p < 0.05 vrocuronium). Patients receiving vecuronium were more likely to require ephedrine and phenylephrine for hypotension (10/15 patients v 5/17 patients for rocuronium, p < 0.05). There were no clinically important differences in hemodynamic variables, oxygen metabolism, or myocardial ischemia between groups. During narcotic induction of anesthesia, rocuronium was associated with lower requirement for vasopressors, faster onset of neuromuscular blockade, and better conditions for mask ventilation and tracheal intubation compared with vecuronium.

A mathematical model of coronary blood flow control: simulation of patient-specific three-dimensional hemodynamics during exercise

PubMed Central

Lau, Kevin D.; Asrress, Kaleab N.; Redwood, Simon R.; Figueroa, C. Alberto

2016-01-01

This work presents a mathematical model of the metabolic feedback and adrenergic feedforward control of coronary blood flow that occur during variations in the cardiac workload. It is based on the physiological observations that coronary blood flow closely follows myocardial oxygen demand, that myocardial oxygen debts are repaid, and that control oscillations occur when the system is perturbed and so are phenomenological in nature. Using clinical data, we demonstrate that the model can provide patient-specific estimates of coronary blood flow changes between rest and exercise, requiring only the patient's heart rate and peak aortic pressure as input. The model can be used in zero-dimensional lumped parameter network studies or as a boundary condition for three-dimensional multidomain Navier-Stokes blood flow simulations. For the first time, this model provides feedback control of the coronary vascular resistance, which can be used to enhance the physiological accuracy of any hemodynamic simulation, which includes both a heart model and coronary arteries. This has particular relevance to patient-specific simulation for which heart rate and aortic pressure recordings are available. In addition to providing a simulation tool, under our assumptions, the derivation of our model shows that β-feedforward control of the coronary microvascular resistance is a mathematical necessity and that the metabolic feedback control must be dependent on two error signals: the historical myocardial oxygen debt, and the instantaneous myocardial oxygen deficit. PMID:26945076

A mathematical model of coronary blood flow control: simulation of patient-specific three-dimensional hemodynamics during exercise.

PubMed

Arthurs, Christopher J; Lau, Kevin D; Asrress, Kaleab N; Redwood, Simon R; Figueroa, C Alberto

2016-05-01

This work presents a mathematical model of the metabolic feedback and adrenergic feedforward control of coronary blood flow that occur during variations in the cardiac workload. It is based on the physiological observations that coronary blood flow closely follows myocardial oxygen demand, that myocardial oxygen debts are repaid, and that control oscillations occur when the system is perturbed and so are phenomenological in nature. Using clinical data, we demonstrate that the model can provide patient-specific estimates of coronary blood flow changes between rest and exercise, requiring only the patient's heart rate and peak aortic pressure as input. The model can be used in zero-dimensional lumped parameter network studies or as a boundary condition for three-dimensional multidomain Navier-Stokes blood flow simulations. For the first time, this model provides feedback control of the coronary vascular resistance, which can be used to enhance the physiological accuracy of any hemodynamic simulation, which includes both a heart model and coronary arteries. This has particular relevance to patient-specific simulation for which heart rate and aortic pressure recordings are available. In addition to providing a simulation tool, under our assumptions, the derivation of our model shows that β-feedforward control of the coronary microvascular resistance is a mathematical necessity and that the metabolic feedback control must be dependent on two error signals: the historical myocardial oxygen debt, and the instantaneous myocardial oxygen deficit. Copyright © 2016 the American Physiological Society.

Association of Placebo, Indomethacin, Ibuprofen, and Acetaminophen With Closure of Hemodynamically Significant Patent Ductus Arteriosus in Preterm Infants: A Systematic Review and Meta-analysis.

PubMed

Mitra, Souvik; Florez, Ivan D; Tamayo, Maria E; Mbuagbaw, Lawrence; Vanniyasingam, Thuva; Veroniki, Areti Angeliki; Zea, Adriana M; Zhang, Yuan; Sadeghirad, Behnam; Thabane, Lehana

2018-03-27

Despite increasing emphasis on conservative management of patent ductus arteriosus (PDA) in preterm infants, different pharmacotherapeutic interventions are used to treat those developing a hemodynamically significant PDA. To estimate the relative likelihood of hemodynamically significant PDA closure with common pharmacotherapeutic interventions and to compare adverse event rates. The databases of MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched from inception until August 15, 2015, and updated on December 31, 2017, along with conference proceedings up to December 2017. Randomized clinical trials that enrolled preterm infants with a gestational age younger than 37 weeks treated with intravenous or oral indomethacin, ibuprofen, or acetaminophen vs each other, placebo, or no treatment for a clinically or echocardiographically diagnosed hemodynamically significant PDA. Data were independently extracted in pairs by 6 reviewers and synthesized with Bayesian random-effects network meta-analyses. Primary outcome: hemodynamically significant PDA closure; secondary: included surgical closure, mortality, necrotizing enterocolitis, and intraventricular hemorrhage. In 68 randomized clinical trials of 4802 infants, 14 different variations of indomethacin, ibuprofen, or acetaminophen were used as treatment modalities. The overall PDA closure rate was 67.4% (2867 of 4256 infants). A high dose of oral ibuprofen was associated with a significantly higher odds of PDA closure vs a standard dose of intravenous ibuprofen (odds ratio [OR], 3.59; 95% credible interval [CrI], 1.64-8.17; absolute risk difference, 199 [95% CrI, 95-258] more per 1000 infants) and a standard dose of intravenous indomethacin (OR, 2.35 [95% CrI, 1.08-5.31]; absolute risk difference, 124 [95% CrI, 14-188] more per 1000 infants). Based on the ranking statistics, a high dose of oral ibuprofen ranked as the best pharmacotherapeutic option for PDA closure (mean surface under the cumulative ranking [SUCRA] curve, 0.89 [SD, 0.12]) and to prevent surgical PDA ligation (mean SUCRA, 0.98 [SD, 0.08]). There was no significant difference in the odds of mortality, necrotizing enterocolitis, or intraventricular hemorrhage with use of placebo or no treatment compared with any of the other treatment modalities. A high dose of oral ibuprofen was associated with a higher likelihood of hemodynamically significant PDA closure vs standard doses of intravenous ibuprofen or intravenous indomethacin; placebo or no treatment did not significantly change the likelihood of mortality, necrotizing enterocolitis, or intraventricular hemorrhage. PROSPERO Identifier: CRD42015015797.

Hemodynamic responses to etomidate versus ketamine-thiopental sodium combination for anesthetic induction in coronary artery bypass graft surgery patients with low ejection fraction: a double-blind, randomized, clinical trial.

PubMed

Habibi, Mohammad Reza; Baradari, Afshin Gholipour; Soleimani, Aria; Emami Zeydi, Amir; Nia, Hamid Sharif; Habibi, Ali; Onagh, Naser

2014-10-01

During induction of anesthesia and intubation, hemodynamic changes are very important; especially in patients with coronary artery disease (CAD) and left ventricular dysfunction. A little information is available on the hemodynamic effects of a combination of ketamine-thiopental for induction of anesthesia in patients undergoing coronary artery bypass graft (CABG) surgery, with impaired ventricular function. The aim of this study was to compare the hemodynamic responses to etomidate versus ketamine-thiopental sodium combination for anesthetic induction in CABG surgery patients with low ejection fraction (EF<45%). In a double blind randomized clinical trial, a total of 100 patients, scheduled for elective CABG surgery were randomly assigned into two groups. These patients received either etomidate or ketamine-thiopental sodium combination at induction of anesthesia. Hemodynamics variable were measured and recorded at baseline, immediately before and after laryngoscopy and intubation, one, two and three minutes after intubation. Also, muscle twitching incidence among patients in two groups was evaluated. No significant differences between the two groups regarding the changes of hemodynamic variables including systolic and diastolic arterial blood pressure, mean arterial pressure and heart rate, were notice (p>0.05). Muscle twitching was not observed in the two groups. Hemodynamic stability after administration of ketamine-thiopental sodium combination for induction of anesthesia in patients undergoing CABG surgery, with impaired ventricular function, supports the clinical impression that this combination is safe in CABG surgery patients with low EF.

Cerebral hematocrit decreases with hemodynamic compromise in carotid artery occlusion: a PET study.

PubMed

Yamauchi, H; Fukuyama, H; Nagahama, Y; Katsumi, Y; Okazawa, H

1998-01-01

This study investigated whether in patients with internal carotid artery occlusion the regional cerebral hematocrit correlates with cerebral hemodynamics or metabolic state and, if so, how the regional cerebral hematocrit changes in the hemodynamically compromised region. We used positron emission tomography to study seven patients with unilateral internal carotid artery occlusion and no cortical infarction in the chronic stage. The distributions of red blood cell and plasma volumes were assessed using oxygen-15-labeled carbon monoxide and copper-62-labeled human serum albumin-dithiosemicarbazone tracers, respectively. The calculated hematocrit value was compared with the hemodynamic and metabolic parameters measured with the oxygen-15 steady-state technique. In the cerebral cortex, the value of the cerebral hematocrit varied but was correlated with the hemodynamic and metabolic status. Stepwise regression analysis revealed that the large vessel hematocrit, the cerebral metabolic rate of oxygen, and the cerebral blood flow or the oxygen extraction fraction accounted for a significant proportion of variance of the cerebral hematocrit. The oxygen extraction fraction and the cerebral metabolic rate of oxygen negatively correlated with the cerebral hematocrit, whereas the cerebral blood flow correlated positively: patients with reduced blood supply relative to metabolic demand (decreased blood flow with increased oxygen extraction fraction) showed low hematocrit values. In carotid artery occlusion in the chronic stage, regional cerebral hematocrit may vary according to cerebral hemodynamics and metabolic status. Regional cerebral hematocrit may decrease with hemodynamic compromise unless oxygen metabolism concomitantly decreases.

Hemodynamic Changes Caused by Flow Diverters in Rabbit Aneurysm Models: Comparison of Virtual and Realistic FD Deployments Based on Micro-CT Reconstruction

PubMed Central

Fang, Yibin; Yu, Ying; Cheng, Jiyong; Wang, Shengzhang; Wang, Kuizhong; Liu, Jian-Min; Huang, Qinghai

2013-01-01

Adjusting hemodynamics via flow diverter (FD) implantation is emerging as a novel method of treating cerebral aneurysms. However, most previous FD-related hemodynamic studies were based on virtual FD deployment, which may produce different hemodynamic outcomes than realistic (in vivo) FD deployment. We compared hemodynamics between virtual FD and realistic FD deployments in rabbit aneurysm models using computational fluid dynamics (CFD) simulations. FDs were implanted for aneurysms in 14 rabbits. Vascular models based on rabbit-specific angiograms were reconstructed for CFD studies. Real FD configurations were reconstructed based on micro-CT scans after sacrifice, while virtual FD configurations were constructed with SolidWorks software. Hemodynamic parameters before and after FD deployment were analyzed. According to the metal coverage (MC) of implanted FDs calculated based on micro-CT reconstruction, 14 rabbits were divided into two groups (A, MC >35%; B, MC <35%). Normalized mean wall shear stress (WSS), relative residence time (RRT), inflow velocity, and inflow volume in Group A were significantly different (P<0.05) from virtual FD deployment, but pressure was not (P>0.05). The normalized mean WSS in Group A after realistic FD implantation was significantly lower than that of Group B. All parameters in Group B exhibited no significant difference between realistic and virtual FDs. This study confirmed MC-correlated differences in hemodynamic parameters between realistic and virtual FD deployment. PMID:23823503

Control groups in recent septic shock trials: a systematic review.

PubMed

Pettilä, Ville; Hjortrup, Peter Buhl; Jakob, Stephan M; Wilkman, Erika; Perner, Anders; Takala, Jukka

2016-12-01

The interpretation of septic shock trial data is profoundly affected by patients, control intervention, co-interventions and selected outcome measures. We evaluated the reporting of control groups in recent septic shock trials. We searched for original articles presenting randomized clinical trials (RCTs) in adult septic shock patients from 2006 to 2016. We included RCTs focusing on septic shock patients with at least two parallel groups and at least 50 patients in the control group. We selected and evaluated data items regarding patients, control group characteristics, and mortality outcomes, and calculated a data completeness score to provide an overall view of quality of reporting. A total of 24 RCTs were included (mean n = 287 patients and 71 % of eligible patients were randomized). Of the 24 studies, 14 (58 %) presented baseline data on vasopressors and 58 % the proportion of patients with elevated lactate values. Five studies (21 %) provided data to estimate the proportion of septic shock patients fulfilling the Sepsis-3 definition. The mean data completeness score was 19 out of 36 (range 8-32). Of 18 predefined control group characteristics, a mean of 8 (range 2-17) were reported. Only 2 (8 %) trials provided adequate data to confirm that their control group treatment represented usual care. Recent trials in septic shock provide inadequate data on the control group treatment and hemodynamic values. We propose a standardized trial dataset to be created and validated, comprising characteristics of patient population, interventions administered, hemodynamic values achieved, surrogate organ dysfunction, and mortality outcomes, to allow better analysis and interpretation of future trial results.

A comparison of the effect of convection against diffusion in hemodynamics and cytokines clearance in an experimental model of septic shock.

PubMed

Herrera-Gutiérrez, Manuel E; Seller-Pérez, Gemma; Arias-Verdú, Dolores; Granados, Maria M; Dominguez, Juan M; Navarrete, Rocío; Morgaz, Juán; Gómez-Villamandos, Rafael

2012-10-01

Replacement therapies based on the use of convection have value for the removal of inflammatory mediators. Such therapies have been proposed for the management of septic shock, but diffusion has not proved useful in this scenario, unless high-flow membranes are used. The exact role of diffusion in these cases remains to be clarified because continuous replacement therapies are usually delivered with low-flow membranes and mixed convection-diffusion modalities. However, studies specifically addressing this problem have not been performed. Our aim was to define the efficacy of hemofiltration (convection) and hemodialysis (diffusion) in cytokine clearance and hemodynamic improvement in an experimental model of septic shock. Shock was induced in 15 beagle dogs (weight 10-15 kg) by infusion of 1 mg/kg of ultrapure Escherichia coli lipopolysaccharide diluted in 20 mL saline for 10 minutes. Five animals were followed without interventions (controls), five animals were treated with convection (100 mL kg h) for 6 hours, and five animals were treated with diffusion (100 mL kg h) for 6 hours. All subjects in the control group died during the study, whereas all treated subjects survived. Mean arterial pressure, cardiac output, systolic variability volume, systemic vascular resistances, dPMax, and pulmonary compliance improved in treated subjects. However, the differences in mean arterial pressure and cardiac output were significant only in the convection group and not in the diffusion-treated group.Tumor necrosis factor α rose equally in all groups and decreased only in treated subjects. Interleukin 6 rose in the three groups but decreased only in the convection group and remained unchanged in the control and diffusion groups. Convection and diffusion improved survival and hemodynamic parameters in a septic shock model. Improvement was more pronounced with convection, a difference that may be explained by convective clearance of cytokines.

Effects of Reiki on Post-cesarean Delivery Pain, Anxiety, and Hemodynamic Parameters: A Randomized, Controlled Clinical Trial.

PubMed

Midilli, Tulay Sagkal; Eser, Ismet

2015-06-01

The aim of this study was to investigate the effect of Reiki on pain, anxiety, and hemodynamic parameters on postoperative days 1 and 2 in patients who had undergone cesarean delivery. The design of this study was a randomized, controlled clinical trial. The study took place between February and July 2011 in the Obstetrical Unit at Odemis Public Hospital in Izmir, Turkey. Ninety patients equalized by age and number of births were randomly assigned to either a Reiki group or a control group (a rest without treatment). Treatment applied to both groups in the first 24 and 48 hours after delivery for a total of 30 minutes to 10 identified regions of the body for 3 minutes each. Reiki was applied for 2 days once a day (in the first 24 and 48 hours) within 4-8 hours of the administration of standard analgesic, which was administered intravenously by a nurse. A visual analog scale and the State Anxiety Inventory were used to measure pain and anxiety. Hemodynamic parameters, including blood pressure (systolic and diastolic), pulse and breathing rates, and analgesic requirements also were recorded. Statistically significant differences in pain intensity (p = .000), anxiety value (p = .000), and breathing rate (p = .000) measured over time were found between the two groups. There was a statistically significant difference between the two groups in the time (p = .000) and number (p = .000) of analgesics needed after Reiki application and a rest without treatment. Results showed that Reiki application reduced the intensity of pain, the value of anxiety, and the breathing rate, as well as the need for and number of analgesics. However, it did not affect blood pressure or pulse rate. Reiki application as a nursing intervention is recommended as a pain and anxiety-relieving method in women after cesarean delivery. Copyright © 2015 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

Gestational changes in left ventricular myocardial contractile function: new insights from two-dimensional speckle tracking echocardiography.

PubMed

Sengupta, Shantanu P; Bansal, Manish; Hofstra, Leonard; Sengupta, Partho P; Narula, Jagat

2017-01-01

The goal of this study was to evaluate the impact of pregnancy and labor on left ventricular (LV) myocardial mechanics using speckle tracking echocardiography (STE). Pregnancy is characterized by profound hormonal and hemodynamic alterations that directly or indirectly influence cardiac structure and function. However, the impact of these changes on left ventricular (LV) myocardial contractile function has not been fully elucidated. In this prospective, longitudinal study, 35 pregnant women underwent serial clinical and echocardiographic evaluation during each trimester and at labor. Two dimensional STE was performed to measure global LV longitudinal, circumferential and radial strain (GLS, GCS and GRS, respectively). Similar data obtained from 20 nulliparous, age-matched women were used as control. All strain values during pregnancy were adjusted for age and hemodynamic parameters. There was a progressive increase in heart rate, systolic and diastolic blood pressure, cardiac output and LV stroke-work during pregnancy. LV end-diastolic and end-systolic volumes also increased progressively but LV ejection fraction remained unaltered, except for slight reduction during the second trimester. Compared to the controls, GLS and GCS were reduced in the first trimester itself (GLS -22.39 ± 5.43 % vs. -18.66 ± 0.64 %, P 0.0002; GCS -20.84 ± 3.20 vs. -17.88 ± 0.09, P < 0.001) and remained so throughout the pregnancy and labor. In contrast, GRS showed an increase during pregnancy which peaked during the second trimester (24.18 ± 0.39 % vs. 18.06 ± 8.14 % in controls, P < 0.001). Alterations in loading conditions during pregnancy are associated with counterbalancing changes in the myocardial mechanics. LV longitudinal and circumferential strain are reduced whereas radial strain is increased. These counterbalancing changes serve to maintain overall LV ejection performance within a normal range and enable the maternal heart to meet the hemodynamic demands of pregnancy and labor.

Real-Time Functional Magnetic Resonance Imaging Amygdala Neurofeedback Changes Positive Information Processing in Major Depressive Disorder.

PubMed

Young, Kymberly D; Misaki, Masaya; Harmer, Catherine J; Victor, Teresa; Zotev, Vadim; Phillips, Raquel; Siegle, Greg J; Drevets, Wayne C; Bodurka, Jerzy

2017-10-15

In participants with major depressive disorder who are trained to upregulate their amygdalar hemodynamic responses during positive autobiographical memory recall with real-time functional magnetic resonance imaging neurofeedback (rtfMRI-nf) training, depressive symptoms diminish. This study tested whether amygdalar rtfMRI-nf also changes emotional processing of positive and negative stimuli in a variety of behavioral and imaging tasks. Patients with major depressive disorder completed two rtfMRI-nf sessions (18 received amygdalar rtfMRI-nf, 16 received control parietal rtfMRI-nf). One week before and following rtfMRI-nf training, participants performed tasks measuring responses to emotionally valenced stimuli including a backward-masking task, which measures the amygdalar hemodynamic response to emotional faces presented for traditionally subliminal duration and followed by a mask, and the Emotional Test Battery in which reaction times and performance accuracy are measured during tasks involving emotional faces and words. During the backward-masking task, amygdalar responses increased while viewing masked happy faces but decreased to masked sad faces in the experimental versus control group following rtfMRI-nf. During the Emotional Test Battery, reaction times decreased to identification of positive faces and during self-identification with positive words and vigilance scores increased to positive faces and decreased to negative faces during the faces dot-probe task in the experimental versus control group following rtfMRI-nf. rtfMRI-nf training to increase the amygdalar hemodynamic response to positive memories was associated with changes in amygdalar responses to happy and sad faces and improved processing of positive stimuli during performance of the Emotional Test Battery. These results may suggest that amygdalar rtfMRI-nf training alters responses to emotional stimuli in a manner similar to antidepressant pharmacotherapy. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Perturbation of the endothelial glycocalyx in post cardiac arrest syndrome.

PubMed

Grundmann, Sebastian; Fink, Katrin; Rabadzhieva, Lyubomira; Bourgeois, Natascha; Schwab, Tilmann; Moser, Martin; Bode, Christoph; Busch, Hans-Joerg

2012-06-01

The prognosis of immediate survivors of cardiac arrest remains poor, as the majority of these patients develops an inflammatory disorder known as the post-cardiac arrest syndrome (PCAS). Recently, the endothelial glycocalyx has been shown to be a key modulator of vascular permeability and inflammation, but its role in PCAS remains unknown. Plasma levels of the glycocalyx components syndecan-1, heparan sulfate and hyaluronic acid were measured in 25 patients after immediate survival of cardiac arrest during different phases of PCAS. Twelve hemodynamically stable patients with acute coronary syndrome served as controls. Cardiac arrest resulted in a significant increase in syndecan-1, heparan sulfate and hyaluronic acid levels compared to controls, indicating a shedding of the endothelial glycocalyx as a pathophysiological component of the post cardiac arrest syndrome. The time course differed between the individual glycocalyx components, with a higher increase of syndecan-1 in the early phase of PCAS (2.8-fold increase vs. controls) and a later peak of heparan sulfate (1.7-fold increase) and hyaluronic acid (2-fold increase) in the intermediate phase. Only the plasma levels of syndecan-1 correlated positively with the duration of CPR and negatively with the glycocalyx-protective protease inhibitor antithrombin III. Plasma levels of both syndecan-1 and heparan sulfate were higher in eventual non-survivors than in survivors of cardiac arrest. Our data for the first time demonstrates a perturbation of the endothelial glycocalyx in immediate survivors of cardiac arrest and indicate a potential important role of this endothelial surface layer in the development of post-cardiac arrest syndrome. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Effects of hydrogen sulfide on hemodynamics, inflammatory response and oxidative stress during resuscitated hemorrhagic shock in rats

PubMed Central

2010-01-01

Introduction Hydrogen sulfide (H2S) has been shown to improve survival in rodent models of lethal hemorrhage. Conversely, other authors have reported that inhibition of endogenous H2S production improves hemodynamics and reduces organ injury after hemorrhagic shock. Since all of these data originate from unresuscitated models and/or the use of a pre-treatment design, we therefore tested the hypothesis that the H2S donor, sodium hydrosulfide (NaHS), may improve hemodynamics in resuscitated hemorrhagic shock and attenuate oxidative and nitrosative stresses. Methods Thirty-two rats were mechanically ventilated and instrumented to measure mean arterial pressure (MAP) and carotid blood flow (CBF). Animals were bled during 60 minutes in order to maintain MAP at 40 ± 2 mm Hg. Ten minutes prior to retransfusion of shed blood, rats randomly received either an intravenous bolus of NaHS (0.2 mg/kg) or vehicle (0.9% NaCl). At the end of the experiment (T = 300 minutes), blood, aorta and heart were harvested for Western blot (inductible Nitric Oxyde Synthase (iNOS), Nuclear factor-κB (NF-κB), phosphorylated Inhibitor κB (P-IκB), Inter-Cellular Adhesion Molecule (I-CAM), Heme oxygenase 1(HO-1), Heme oxygenase 2(HO-2), as well as nuclear respiratory factor 2 (Nrf2)). Nitric oxide (NO) and superoxide anion (O2-) were also measured by electron paramagnetic resonance. Results At the end of the experiment, control rats exhibited a decrease in MAP which was attenuated by NaHS (65 ± 32 versus 101 ± 17 mmHg, P < 0.05). CBF was better maintained in NaHS-treated rats (1.9 ± 1.6 versus 4.4 ± 1.9 ml/minute P < 0.05). NaHS significantly limited shock-induced metabolic acidosis. NaHS also prevented iNOS expression and NO production in the heart and aorta while significantly reducing NF-kB, P-IκB and I-CAM in the aorta. Compared to the control group, NaHS significantly increased Nrf2, HO-1 and HO-2 and limited O2- release in both aorta and heart (P < 0.05). Conclusions NaHS is protective against the effects of ischemia reperfusion induced by controlled hemorrhage in rats. NaHS also improves hemodynamics in the early resuscitation phase after hemorrhagic shock, most likely as a result of attenuated oxidative stress. The use of NaHS hence appears promising in limiting the consequences of ischemia reperfusion (IR). PMID:20836847

Non-invasive quantification of hemodynamics in human choriocapillaries

NASA Astrophysics Data System (ADS)

Yu, Huidan (Whitney); Chen, Rou; An, Senyou; McDonough, James; Gelfand, Bradley; Yao, Jun

2016-11-01

The development of retinal disease is inextricably linked to defects in the choroidal blood supply. However, to date a description of the hemodynamics in the human choroidal circulation is lacking. Through high resolution choroidal vascular network mapped from immunofluorescent labeling and confocal microscopy of human cadaver donor eyes. We noninvasively quantify hemodynamics including velocity, pressure, and wall-shear stress (WSS) in choriocapillaries through mesoscale modeling and GPU-accelerated fast computation. This is the first-ever map of hemodynamic parameters (WSS, pressure, and velocity) in anatomically accurate human choroidal vasculature in health and disease. The pore scale simulation results are used to evaluate porous media models with the same porosity and boundary conditions. School of Medicine, Indiana University.

Right ventricular effects of intracoronary delivery of mesenchymal stem cells (MSC) in an animal model of pressure overload heart failure.

PubMed

Molina, Ezequiel J; Palma, Jon; Gupta, Dipin; Gaughan, John P; Houser, Steven; Macha, Mahender

2009-12-01

In a rat model of left ventricular pressure overload hypertrophy with biventricular failure, we studied the effects of intracoronary delivery of mesenchymal stem cells (MCS) upon right ventricular hemodynamic performance, profiles of local inflammation and apoptosis, and determinants of extracellular matrix remodeling. Sprague-Dawley rats underwent aortic banding and were followed by echocardiography. After a decrease in left ventricular fractional shortening of 25% from the baseline (relative 50% reduction), animals were randomized to an intracoronary injection of MSC (n=28) or PBS (n=20). Right ventricular hemodynamic assessment and measurement of local inflammatory markers, proapoptotic factors, and determinants of extracellular matrix remodeling were performed on post-transplantation day 7, 14, 21 or 28. MSC injection improved right ventricular systolic function in the MSC group compared to the control group (mean+/-SD, max dP/dt 772+/-272 mm Hg/s vs. 392+/-132 at 28 days, P<0.01). Diastolic function was similarly improved (mean+/-SD, max -dP/dt -558+/-171 mm Hg/s vs. -327+/-131 at 28 days, P<0.05). Right ventricular levels of IL-1, IL-6, TNF-alpha, bax, bak and p38 were significantly decreased in the MSC treated animals. Expression of MMP-3, MMP-6, MMP-9, TIMP-1 and TIMP-3 declined in the MSC group compared with controls after 28 days. In this model of left ventricular pressure overload hypertrophy and biventricular failure, intracoronary delivery of MSC was associated with an improvement in the right ventricular hemodynamic performance, profiles of local inflammation and apoptosis, and determinants of extracellular matrix remodeling.

[Alterations of cardiac hemodynamics, sodium current and L-type calcium current in rats with L-thyroxine-induced cardiomyopathy].

PubMed

Wang, Jing; Zhang, Wei-Dong; Lin, Mu-Sen; Zhai, Qing-Bo; Yu, Feng

2010-08-25

The aim of the present study is to investigate the alterations of cardiac hemodynamics, sodium current (I(Na)) and L-type calcium current (I(Ca-L)) in the cardiomyopathic model of rats. The model of cardiomyopathy was established by intraperitoneal injection of L-thyroxine (0.5 mg/kg) for 10 d. The hemodynamics was measured with biological experimental system, and then I(Na) and I(Ca-L) were recorded by using whole cell patch clamp technique. The results showed that left ventricular systolic pressure (LVSP), left ventricular developed pressure (LVDP), +/-dp/dt(max) in cardiomyopathic group were significantly lower than those in the control group, while left ventricular end-diastolic pressure (LVEDP) in cardiomyopathic group was higher than that in the control group. Intraperitoneal injection of L-thyroxine significantly increased the current density of I(Na) [(-26.2+/-3.2) pA/pF vs (-21.1+/-6.3) pA/pF, P<0.01], shifted steady-state activation and inactivation curves negatively, and markedly prolonged the time constant of recovery from inactivation. On the other hand, the injection of L-thyroxine significantly increased the current density of I(Ca-L) [(-7.9+/-0.8) pA/pF vs (-5.4+/-0.6) pA/pF, P<0.01)], shifted steady-state activation and inactivation curves negatively, and obviously shortened the time constant of recovery from inactivation. In conclusion, the cardiac performance of cardiomyopathic rats is similar to that of rats with heart failure, in which the current density of I(Na) and especially the I(Ca-L) are enhanced, suggesting that calcium channel blockade and a decrease in Na(+) permeability of membrane may play an important role in the treatment of cardiomyopathy.

Computational network model prediction of hemodynamic alterations due to arteriolar remodeling in interval sprint trained skeletal muscle.

PubMed

Binder, Kyle W; Murfee, Walter L; Song, Ji; Laughlin, M Harold; Price, Richard J

2007-01-01

Exercise training is known to enhance skeletal muscle blood flow capacity, with high-intensity interval sprint training (IST) primarily affecting muscles with a high proportion of fast twitch glycolytic fibers. The objective of this study was to determine the relative contributions of new arteriole formation and lumenal arteriolar remodeling to enhanced flow capacity and the impact of these adaptations on local microvascular hemodynamics deep within the muscle. The authors studied arteriolar adaptation in the white/mixed-fiber portion of gastrocnemius muscles of IST (6 bouts of running/day; 2.5 min/bout; 60 m/min speed; 15% grade; 4.5 min rest between bouts; 5 training days/wk; 10 wks total) and sedentary (SED) control rats using whole-muscle Microfil casts. Dimensional and topological data were then used to construct a series of computational hemodynamic network models that incorporated physiological red blood cell distributions and hematocrit and diameter dependent apparent viscosities. In comparison to SED controls, IST elicited a significant increase in arterioles/order in the 3A through 6A generations. Predicted IST and SED flows through the 2A generation agreed closely with in vivo measurements made in a previous study, illustrating the accuracy of the model. IST shifted the bulk of the pressure drop across the network from the 3As to the 4As and 5As, and flow capacity increased from 0.7 mL/min in SED to 1.5 mL/min in IST when a driving pressure of 80 mmHg was applied. The primary adaptation to IST is an increase in arterioles in the 3A through 6A generations, which, in turn, creates an approximate doubling of flow capacity and a deeper penetration of high pressure into the arteriolar network.

Ligation of the Jugular Veins Does Not Result in Brain Inflammation or Demyelination in Mice

PubMed Central

Wojtkiewicz, Gregory R.; Pulli, Benjamin; Iwamoto, Yoshiko; Ueno, Takuya; Waterman, Peter; Truelove, Jessica; Oklu, Rahmi; Chen, John W.

2012-01-01

An alternative hypothesis has been proposed implicating chronic cerebrospinal venous insufficiency (CCSVI) as a potential cause of multiple sclerosis (MS). We aimed to evaluate the validity of this hypothesis in a controlled animal model. Animal experiments were approved by the institutional animal care committee. The jugular veins in SJL mice were ligated bilaterally (n = 20), and the mice were observed for up to six months after ligation. Sham-operated mice (n = 15) and mice induced with experimental autoimmune encephalomyelitis (n = 8) were used as negative and positive controls, respectively. The animals were evaluated using CT venography and 99mTc-exametazime to assess for structural and hemodynamic changes. Imaging was performed to evaluate for signs of blood-brain barrier (BBB) breakdown and neuroinflammation. Flow cytometry and histopathology were performed to assess inflammatory cell populations and demyelination. There were both structural changes (stenosis, collaterals) in the jugular venous drainage and hemodynamic disturbances in the brain on Tc99m-exametazime scintigraphy (p = 0.024). In the JVL mice, gadolinium MRI and immunofluorescence imaging for barrier molecules did not reveal evidence of BBB breakdown (p = 0.58). Myeloperoxidase, matrix metalloproteinase, and protease molecular imaging did not reveal signs of increased neuroinflammation (all p>0.05). Flow cytometry and histopathology also did not reveal increase in inflammatory cell infiltration or population shifts. No evidence of demyelination was found, and the mice remained without clinical signs. Despite the structural and hemodynamic changes, we did not identify changes in the BBB permeability, neuroinflammation, demyelination, or clinical signs in the JVL group compared to the sham group. Therefore, our murine model does not support CCSVI as a cause of demyelinating diseases such as multiple sclerosis. PMID:22457780

Open-lung protective ventilation with pressure control ventilation, high-frequency oscillation, and intratracheal pulmonary ventilation results in similar gas exchange, hemodynamics, and lung mechanics.

PubMed

Sedeek, Khaled A; Takeuchi, Muneyuki; Suchodolski, Klaudiusz; Vargas, Sara O; Shimaoka, Motomu; Schnitzer, Jay J; Kacmarek, Robert M

2003-11-01

Pressure control ventilation (PCV), high-frequency oscillation (HFO), and intratracheal pulmonary ventilation (ITPV) may all be used to provide lung protective ventilation in acute respiratory distress syndrome, but the specific approach that is optimal remains controversial. Saline lavage was used to produce acute respiratory distress syndrome in 21 sheep randomly assigned to receive PCV, HFO, or ITPV as follows: positive end-expiratory pressure (PCV and ITPV) and mean airway pressure (HFO) were set in a pressure-decreasing manner after lung recruitment that achieved a ratio of Pao2/Fio2 > 400 mmHg. Respiratory rates were 30 breaths/min, 120 breaths/min, and 8 Hz, respectively, for PCV, ITPV, and HFO. Eucapnia was targeted with peak carinal pressure of no more than 35 cm H2O. Animals were then ventilated for 4 h. There were no differences among groups in gas exchange, lung mechanics, or hemodynamics. Tidal volume (PCV, 8.9 +/- 2.1 ml/kg; ITPV, 2.7 +/- 0.8 ml/kg; HFO, approximately 2.0 ml/kg) and peak carinal pressure (PCV, 30.6 +/- 2.6 cm H2O; ITPV, 22.3 +/- 4.8 cm H2O; HFO, approximately 24.3 cm H2O) were higher in PCV. Pilot histologic data showed greater interstitial hemorrhage and alveolar septal expansion in PCV than in HFO or ITPV. These data indicate that HFO, ITPV, and PCV when applied with an open-lung protective ventilatory strategy results in the same gas exchange, lung mechanics, and hemodynamic response, but pilot data indicate that lung injury may be greater with PCV.

Physiologic Cryoamputation in Managing Critically Ill Patients with Septic, Advanced Acute Limb Ischemia.

PubMed

Chen, Samuel L; Kuo, Isabella J; Kabutey, Nii-Kabu; Fujitani, Roy M

2017-07-01

Certain critically ill patients with advanced acute limb ischemia with a nonviable extremity may be unsuitable for transport to the operating room to undergo definitive amputation. In these unstable patients, rapid regional cryotherapy allows for prompt infectious source control and correction of hemodynamic and metabolic abnormalities, thereby lessening the risk associated with definitive surgical amputation. We describe our refined technique for lower extremity physiologic cryoamputation and review our institutional experience. After adequate analgesia is administered to the patient, a heating pad is secured circumferentially at the proximal amputation margin and the affected extremity is placed in a customized Styrofoam cooler. A circumferential seal is secured at the proximal chill zone without use of a tourniquet and dry ice is placed into the cooler to surround the entire affected leg. Delayed definitive lower extremity amputation is later performed when hemodynamic and metabolic derangements are corrected. We reviewed 5 patients who underwent lower extremity cryoamputation with this technique identified at our institution between 2005 and 2015. Age ranged from 31 to 79 years old. All presented with severe foot infection and septic shock requiring vasopressor support. All 5 patients stabilized hemodynamically following the initial cryoamputation and later underwent definitive lower extremity amputation, with a median time of 3 days following initial cryoamputation. Lower extremity physiologic cryoamputation is an effective, immediate bedside procedure that can provide local source control and the opportunity for correction of metabolic derangements in initially unstable patients to lessen the risk for definitive major lower extremity amputation. Refinement of the cryoamputation technique, as described in this report, allows for a predictable and reproducible physiologic amputation. Copyright © 2017 Elsevier Inc. All rights reserved.

Curvature effect on hemodynamic conditions at the inner bend of the carotid siphon and its relation to aneurysm formation.

PubMed

Lauric, Alexandra; Hippelheuser, James; Safain, Mina G; Malek, Adel M

2014-09-22

Although high-impact hemodynamic forces are thought to lead to cerebral aneurysmal change, little is known about the aneurysm formation on the inner aspect of vascular bends such as the internal carotid artery (ICA) siphon where wall shear stress (WSS) is expected to be low. This study evaluates the effect of vessel curvature and hemodynamics on aneurysm formation along the inner carotid siphon. Catheter 3D-rotational angiographic volumes of 35 ICA (10 aneurysms, 25 controls) were evaluated in 3D for radius of curvature and peak curvature of the siphon bend, followed by univariate statistical analysis. Computational fluid dynamic (CFD) simulations were performed on patient-derived models after aneurysm removal and on synthetic variants of increasing curvature. Peak focal siphon curvature was significantly higher in aneurysm bearing ICAs (0.36 ± 0.045 vs. 0.30 ± 0.048 mm(-1), p=0.003), with no difference in global radius of curvature (p=0.36). In CFD simulations, increasing parametric curvature tightness (from 5 to 3mm radius) resulted in dramatic increase of WSS and WSS gradient magnitude (WSSG) on the inner wall of the bend. In patient-derived data, the location of aneurysms coincided with regions of low WSS (<4 Pa) flanked by high WSS and WSSG peaks. WSS peaks correlated with the aneurysm neck. In contrast, control siphon bends displayed low, almost constant, WSS and WSSG profiles with little spatial variation. High bend curvature induces dynamically fluctuating high proximal WSS and WSSG followed by regions of flow stasis and recirculation, leading to local conditions known to induce destructive vessel wall remodeling and aneurysmal initiation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparison of Customized Cutting Block and Conventional Cutting Instrument in Total Knee Arthroplasty: A Randomized Controlled Trial.

PubMed

Tammachote, Nattapol; Panichkul, Phonthakorn; Kanitnate, Supakit

2018-03-01

Customized cutting block (CCB) was designed to ensure the accurate alignment of knee prostheses during total knee arthroplasty. Given the paucity of CCB efficacy data, we compare CCB with conventional cutting guide using a randomized controlled trial. One hundred eight osteoarthritic knee patients underwent total knee arthroplasty by one experienced surgeon were randomized to receive CCB (n = 54) or conventional cutting instrument (CCI) surgery (n = 54). The primary outcomes were limb alignment, prostheses position, and operative time. The secondary outcomes were hemodynamic alteration after surgery, functional outcomes (modified Western Ontario and McMaster University Osteoarthritis Index) and range of motion at 2 years after surgery. Mean hip-knee-ankle angle in the CCB group was 179.4° ± 1.8° vs 179.1° ± 2.4° in the CCI group, Δ = 0 (95% confidence interval [CI] -0.6 to 1.1, P = .55). Mean operative time was faster in the CCB arm: 93 ± 12 vs 104 ± 12 minutes, Δ = 11 (95% CI -16.7 to -7.2, P < .0001). There were no differences in hemodynamic parameters, mean blood loss (446 [CCB] vs 514 mL [CCI], Δ = -68 [95% CI -138 to 31 mL, P = .21]), postoperative hemoglobin changes, incidence of hypotension (systolic <90 mm Hg), oliguria, and rates of blood transfusion. Functional outcomes and range of motion were also similar. There was no improvement in alignment, hemodynamic changes, blood loss, and knee functional outcomes. CCB reduced surgical time by 11 minutes in our population. CCB cost-effectiveness should be further investigated. Copyright © 2017 Elsevier Inc. All rights reserved.

Increased blood flow in the anterior humeral circumflex artery correlates with night pain in patients with rotator cuff tear.

PubMed

Terabayashi, Nobuo; Watanabe, Tsuneo; Matsumoto, Kazu; Takigami, Iori; Ito, Yoshiki; Fukuta, Masashi; Akiyama, Haruhiko; Shimizu, Katsuji

2014-09-01

Night pain is a particularly vexing symptom in patients with rotator cuff tear. It disturbs sleep and decreases quality of life, and there is no consensus regarding its etiology. Based on arthroscopic surgical observations of synovitis around the rotator interval or capsule surface in rotator cuff tear, we hypothesized that blood flow from the artery feeding the capsule increases blood supply to the synovium. This study aimed to investigate the relationship between blood flow and night pain using pulse Doppler ultrasonography. A series of 47 consecutive patients with rotator cuff tear was evaluated. The peak systolic velocity and resistance index of blood flow in the ascending branch of the anterior humeral circumflex artery were evaluated using pulse Doppler ultrasonography. We also investigated 20 normal shoulders in healthy volunteers. The peak systolic velocity and resistance index were compared between affected and unaffected sides in patients and between dominant and nondominant sides in controls. Anterior humeral circumflex artery peak systolic velocity and resistance index did not differ between sides in control subjects or in patients with rotator cuff tear without night pain. However, anterior humeral circumflex artery peak systolic velocity and resistance index did differ significantly between sides in patients with rotator cuff tear with night pain. This study revealed anterior humeral circumflex artery hemodynamics in patients with rotator cuff tear and normal subjects using Doppler ultrasonography. Night pain, particularly involving aching, appears to be related to the hemodynamics. These findings suggest that investigating the hemodynamics of patients with rotator cuff tear with night pain may lead to greater understanding of the etiology of this symptom.

Effects of transcranial direct current stimulation on craving, heart-rate variability and prefrontal hemodynamics during smoking cue exposure.

PubMed

Kroczek, A M; Häußinger, F B; Rohe, T; Schneider, S; Plewnia, C; Batra, A; Fallgatter, A J; Ehlis, A-C

2016-11-01

Drug-related cue exposure elicits craving and risk for relapse during recovery. Transcranial direct current stimulation is a promising research tool and possible treatment for relapse prevention. Enhanced functional neuroconnectivity is discussed as a treatment target. The goal of this research was to examine whether transcranial direct current stimulation affected cortical hemodynamic indicators of functional connectivity, craving, and heart rate variability during smoking-related cue exposure in non-treatment-seeking smokers. In vivo smoking cue exposure supported by a 2mA transcranial direct current stimulation (anode: dorsolateral prefrontal cortex, cathode: orbitofrontal cortex; placebo-controlled, randomized, double-blind) in 29 (age: M=25, SD=5) German university students (smoking at least once a week). Cue reactivity was assessed on an autonomous (heart rate variability) and a subjective level (craving ratings). Functional near-infrared spectroscopy measured changes in the concentration of deoxygenated hemoglobin, and seed-based correlation analysis was used to quantify prefrontal connectivity of brain regions involved in cue reactivity. Cue exposure elicited increased subjective craving and heart rate variability changes in smokers. Connectivity between the orbitofrontal and dorsolateral prefrontal cortex was increased in subjects receiving verum compared to placebo stimulation (d=0.66). Hemodynamics in the left dorsolateral prefrontal cortex, however, increased in the group receiving sham stimulation (η 2 =0.140). Transcranial direct current stimulation did not significantly alter craving or heart rate variability during cue exposure. Prefrontal connectivity - between regions involved in the processing of reinforcement value and cognitive control - was increased by anodal transcranial direct current stimulation during smoking cue exposure. Possible clinical implications should be considered in future studies. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Percutaneous Hepatic Perfusion (PHP) with Melphalan as a Treatment for Unresectable Metastases Confined to the Liver.

PubMed

de Leede, Eleonora M; Burgmans, Mark C; Martini, Christian H; Tijl, Fred G J; van Erkel, Arian R; Vuyk, Jaap; Kapiteijn, Ellen; Verhoef, Cornelis; van de Velde, Cornelis J H; Vahrmeijer, Alexander L

2016-07-31

Unresectable liver metastases of colorectal cancer can be treated with systemic chemotherapy, aiming to limit the disease, extend survival or turn unresectable metastases into resectable ones. Some patients however, suffer from side effects or progression under systemic treatment. For patients with metastasized uveal melanoma there are no standard systemic therapy options. For patients without extrahepatic disease, isolated liver perfusion (IHP) may enable local disease control with limited systemic side effects. Previously, this was performed during open surgery with satisfying results, but morbidity and mortality related to the open procedure, prohibited a widespread application. Therefore, percutaneous hepatic perfusion (PHP) with simultaneous chemofiltration was developed. Besides decreasing morbidity and mortality, this procedure can be repeated, hopefully leading to a higher response rate and improved survival (by local control of disease). During PHP, catheters are placed in the proper hepatic artery, to infuse the chemotherapeutic agent, and in the inferior caval vein to aspirate the chemosaturated blood returning through the hepatic veins. The caval vein catheter is a double balloon catheter that prohibits leakage into the systemic circulation. The blood returning from the hepatic veins is aspirated through the catheter fenestrations and then perfused through an extra-corporeal filtration system. After filtration, the blood is returned to the patient by a third catheter in the right internal jugular vein. During PHP a high dose of melphalan is infused into the liver, which is toxic and would lead to life threatening complications when administered systemically. Because of the significant hemodynamic instability resulting from the combination of caval vein occlusion and chemofiltration, hemodynamic monitoring and hemodynamic support is of paramount importance during this complex procedure.

Analysis of volatile compounds in exhaled breath condensate in patients with severe pulmonary arterial hypertension.

PubMed

Mansoor, J K; Schelegle, Edward S; Davis, Cristina E; Walby, William F; Zhao, Weixiang; Aksenov, Alexander A; Pasamontes, Alberto; Figueroa, Jennifer; Allen, Roblee

2014-01-01

An important challenge to pulmonary arterial hypertension (PAH) diagnosis and treatment is early detection of occult pulmonary vascular pathology. Symptoms are frequently confused with other disease entities that lead to inappropriate interventions and allow for progression to advanced states of disease. There is a significant need to develop new markers for early disease detection and management of PAH. Exhaled breath condensate (EBC) samples were compared from 30 age-matched normal healthy individuals and 27 New York Heart Association functional class III and IV idiopathic pulmonary arterial hypertenion (IPAH) patients, a subgroup of PAH. Volatile organic compounds (VOC) in EBC samples were analyzed using gas chromatography/mass spectrometry (GC/MS). Individual peaks in GC profiles were identified in both groups and correlated with pulmonary hemodynamic and clinical endpoints in the IPAH group. Additionally, GC/MS data were analyzed using autoregression followed by partial least squares regression (AR/PLSR) analysis to discriminate between the IPAH and control groups. After correcting for medicaitons, there were 62 unique compounds in the control group, 32 unique compounds in the IPAH group, and 14 in-common compounds between groups. Peak-by-peak analysis of GC profiles of IPAH group EBC samples identified 6 compounds significantly correlated with pulmonary hemodynamic variables important in IPAH diagnosis. AR/PLSR analysis of GC/MS data resulted in a distinct and identifiable metabolic signature for IPAH patients. These findings indicate the utility of EBC VOC analysis to discriminate between severe IPAH and a healthy population; additionally, we identified potential novel biomarkers that correlated with IPAH pulmonary hemodynamic variables that may be important in screening for less severe forms IPAH.

Analysis of Volatile Compounds in Exhaled Breath Condensate in Patients with Severe Pulmonary Arterial Hypertension

PubMed Central

Mansoor, J. K.; Schelegle, Edward S.; Davis, Cristina E.; Walby, William F.; Zhao, Weixiang; Aksenov, Alexander A.; Pasamontes, Alberto; Figueroa, Jennifer; Allen, Roblee

2014-01-01

Background An important challenge to pulmonary arterial hypertension (PAH) diagnosis and treatment is early detection of occult pulmonary vascular pathology. Symptoms are frequently confused with other disease entities that lead to inappropriate interventions and allow for progression to advanced states of disease. There is a significant need to develop new markers for early disease detection and management of PAH. Methodolgy and Findings Exhaled breath condensate (EBC) samples were compared from 30 age-matched normal healthy individuals and 27 New York Heart Association functional class III and IV idiopathic pulmonary arterial hypertenion (IPAH) patients, a subgroup of PAH. Volatile organic compounds (VOC) in EBC samples were analyzed using gas chromatography/mass spectrometry (GC/MS). Individual peaks in GC profiles were identified in both groups and correlated with pulmonary hemodynamic and clinical endpoints in the IPAH group. Additionally, GC/MS data were analyzed using autoregression followed by partial least squares regression (AR/PLSR) analysis to discriminate between the IPAH and control groups. After correcting for medicaitons, there were 62 unique compounds in the control group, 32 unique compounds in the IPAH group, and 14 in-common compounds between groups. Peak-by-peak analysis of GC profiles of IPAH group EBC samples identified 6 compounds significantly correlated with pulmonary hemodynamic variables important in IPAH diagnosis. AR/PLSR analysis of GC/MS data resulted in a distinct and identifiable metabolic signature for IPAH patients. Conclusions These findings indicate the utility of EBC VOC analysis to discriminate between severe IPAH and a healthy population; additionally, we identified potential novel biomarkers that correlated with IPAH pulmonary hemodynamic variables that may be important in screening for less severe forms IPAH. PMID:24748102

[Hemodynamic monitoring in the critically patient. Recomendations of the Cardiological Intensive Care and CPR Working Group of the Spanish Society of Intensive Care and Coronary Units].

PubMed

Ochagavía, A; Baigorri, F; Mesquida, J; Ayuela, J M; Ferrándiz, A; García, X; Monge, M I; Mateu, L; Sabatier, C; Clau-Terré, F; Vicho, R; Zapata, L; Maynar, J; Gil, A

2014-04-01

Hemodynamic monitoring offers valuable information on cardiovascular performance in the critically ill, and has become a fundamental tool in the diagnostic approach and in the therapy guidance of those patients presenting with tissue hypoperfusion. From introduction of the pulmonary artery catheter to the latest less invasive technologies, hemodynamic monitoring has been surrounded by many questions regarding its usefulness and its ultimate impact on patient prognosis. The Cardiological Intensive Care and CPR Working Group (GTCIC-RCP) of the Spanish Society of Intensive Care and Coronary Units (SEMICYUC) has recently impulsed the development of an updating series in hemodynamic monitoring. Now, a final series of recommendations are presented in order to analyze essential issues in hemodynamics, with the purpose of becoming a useful tool for residents and critical care practitioners involved in the daily management of critically ill patients. Copyright © 2013 Elsevier España, S.L. and SEMICYUC. All rights reserved.

Functional MRI Detection of Hemodynamic Response of Repeated Median Nerve Stimulation

PubMed Central

Ai, Leo; Oya, Hiroyuki; Howard, Matthew; Xiong, Jinhu

2012-01-01

Median nerve stimulation is a commonly used technique in the clinical setting to determine areas of neuronal function in the brain. Neuronal activity of repeated median nerve stimulation is well studied. The cerebral hemodynamic response of the stimulation, on the other hand, is not very clear. In this study, we investigate how cerebral hemodynamics behaves over time using the same repeated median nerve stimulation. Ten subjects received constant repeated electrical stimulation to the right median nerve. Each subject had fMRI scans while receiving said stimulations for seven runs. Our results show that the BOLD signal significantly decreases across each run. Significant BOLD signal decreases can also be seen within runs. These results are consistent with studies that have studied the hemodynamic habituation effect with other forms of stimulation. However, the results do not completely agree with the findings of studies where evoked potentials were examined. Thus, further inquiry of how evoked potentials and cerebral hemodynamics are coupled when using constant stimulations is needed. PMID:23228312

[Study of sharing platform of web-based enhanced extracorporeal counterpulsation hemodynamic waveform data].

PubMed

Huang, Mingbo; Hu, Ding; Yu, Donglan; Zheng, Zhensheng; Wang, Kuijian

2011-12-01

Enhanced extracorporeal counterpulsation (EECP) information consists of both text and hemodynamic waveform data. At present EECP text information has been successfully managed through Web browser, while the management and sharing of hemodynamic waveform data through Internet has not been solved yet. In order to manage EECP information completely, based on the in-depth analysis of EECP hemodynamic waveform file of digital imaging and communications in medicine (DICOM) format and its disadvantages in Internet sharing, we proposed the use of the extensible markup language (XML), which is currently the Internet popular data exchange standard, as the storage specification for the sharing of EECP waveform data. Then we designed a web-based sharing system of EECP hemodynamic waveform data via ASP. NET 2.0 platform. Meanwhile, we specifically introduced the four main system function modules and their implement methods, including DICOM to XML conversion module, EECP waveform data management module, retrieval and display of EECP waveform module and the security mechanism of the system.

Measurement of hemodynamics during postural changes using a new wearable cephalic laser blood flowmeter.

PubMed

Fujikawa, Tetsuya; Tochikubo, Osamu; Kura, Naoki; Kiyokura, Takanori; Shimada, Junichi; Umemura, Satoshi

2009-10-01

Patients with orthostatic hypotension have pathologic hemodynamics related to changes in body posture. A new cephalic laser blood flowmeter that can be worn on the tragus to investigate the hemodynamics upon rising from a sitting or squatting posture was developed. The relationship between cephalic hemodynamics and cerebral ischemic symptoms in 63 subjects in a sitting, squatting, and standing positions using the new device was evaluated. Transient decrease in blood pressure within 15 s after rising to an erect position possibly causes dizziness, syncope, and fall. Subjects exhibiting dizziness upon standing showed a significant decrease in the cephalic blood flow (CBF) and indirect beat-to-beat systolic blood pressure, as monitored by the Finometer, and a significant correlation was observed between the drop ratio (drop value on rising/mean value in the squatting position) of CBF and that of systolic blood pressure. This new wearable CBF-meter is potentially useful for estimating cephalic hemodynamics and objectively diagnosing cerebral ischemic symptoms of subjects in a standing posture.

Computational fluid dynamics assisted characterization of parafoveal hemodynamics in normal and diabetic eyes using adaptive optics scanning laser ophthalmoscopy.

PubMed

Lu, Yang; Bernabeu, Miguel O; Lammer, Jan; Cai, Charles C; Jones, Martin L; Franco, Claudio A; Aiello, Lloyd Paul; Sun, Jennifer K

2016-12-01

Diabetic retinopathy (DR) is the leading cause of visual loss in working-age adults worldwide. Previous studies have found hemodynamic changes in the diabetic eyes, which precede clinically evident pathological alterations of the retinal microvasculature. There is a pressing need for new methods to allow greater understanding of these early hemodynamic changes that occur in DR. In this study, we propose a noninvasive method for the assessment of hemodynamics around the fovea (a region of the eye of paramount importance for vision). The proposed methodology combines adaptive optics scanning laser ophthalmoscopy and computational fluid dynamics modeling. We compare results obtained with this technique with in vivo measurements of blood flow based on blood cell aggregation tracking. Our results suggest that parafoveal hemodynamics, such as capillary velocity, wall shear stress, and capillary perfusion pressure can be noninvasively and reliably characterized with this method in both healthy and diabetic retinopathy patients.

Hydrodynamics Analysis and CFD Simulation of Portal Venous System by TIPS and LS.

PubMed

Wang, Meng; Zhou, Hongyu; Huang, Yaozhen; Gong, Piyun; Peng, Bing; Zhou, Shichun

2015-06-01

In cirrhotic patients, portal hypertension is often associated with a hyperdynamic changes. Transjugular Intrahepatic Portosystemic Shunt (TIPS) and Laparoscopic splenectomy are both treatments for liver cirrhosis due to portal hypertension. While, the two different interventions have different effects on hemodynamics after operation and the possibilities of triggering PVT are different. How hemodynamics of portal vein system evolving with two different operations remain unknown. Based on ultrasound and established numerical methods, CFD technique is applied to analyze hemodynamic changes after TIPS and Laparoscopic splenectomy. In this paper, we applied two 3-D flow models to the hemodynamic analysis for two patients who received a TIPS and a laparoscopic splenectomy, both therapies for treating portal hypertension induced diseases. The current computer simulations give a quantitative analysis of the interplay between hemodynamics and TIPS or splenectomy. In conclusion, the presented computational model can be used for the theoretical analysis of TIPS and laparoscopic splenectomy, clinical decisions could be made based on the simulation results with personal properly treatment.

Computational fluid dynamics assisted characterization of parafoveal hemodynamics in normal and diabetic eyes using adaptive optics scanning laser ophthalmoscopy

PubMed Central

Lu, Yang; Bernabeu, Miguel O.; Lammer, Jan; Cai, Charles C.; Jones, Martin L.; Franco, Claudio A.; Aiello, Lloyd Paul; Sun, Jennifer K.

2016-01-01

Diabetic retinopathy (DR) is the leading cause of visual loss in working-age adults worldwide. Previous studies have found hemodynamic changes in the diabetic eyes, which precede clinically evident pathological alterations of the retinal microvasculature. There is a pressing need for new methods to allow greater understanding of these early hemodynamic changes that occur in DR. In this study, we propose a noninvasive method for the assessment of hemodynamics around the fovea (a region of the eye of paramount importance for vision). The proposed methodology combines adaptive optics scanning laser ophthalmoscopy and computational fluid dynamics modeling. We compare results obtained with this technique with in vivo measurements of blood flow based on blood cell aggregation tracking. Our results suggest that parafoveal hemodynamics, such as capillary velocity, wall shear stress, and capillary perfusion pressure can be noninvasively and reliably characterized with this method in both healthy and diabetic retinopathy patients. PMID:28078170

[Second Clinical Consensus of the Ibero-American Society of Neonatology: hemodynamic management of newborns].

PubMed

Golombek, Sergio G; Fariña, Diana; Sola, Augusto; Baquero, Hernando; Cabañas, Fernando; Dominguez, Fernando; Fajardo, Carlos; Goldsmit, Gustavo S; Flores, Gabriel Lara; Lee, Mario; Varela, Lourdes Lemus; Mariani, Gonzalo; Miura, Ernani; Pérez, Jose Maria; Zambosco, Guillermo; Pellicer, Adelina; Bancalari, Eduardo

2011-04-01

This study reports on the process and results of the Second Clinical Consensus of the Ibero-American Society of Neonatology. Eighty neonatologists from 23 countries were invited to collaborate and participate in the event. Several questions of clinical-physiological importance in the hemodynamic management of newborns were addressed. Participants were divided into groups to facilitate interaction and teamwork, with instructions to respond to three to five questions by analyzing the literature and local factors. Meeting in Mar del Plata, Argentina, the Consensus Group served as a form for various presentations and discussions. In all, 54 neonatologists from 21 countries attended, with the objective of reaching a consensus on such matters as concepts and definitions of hemodynamic instability, the physiopathology of hemodynamic compromise, recommended therapy strategies, and hemodynamic monitoring. It is hoped that this international experience will serve as a useful initiative for future consensus building and reduction of the existing disparities among the countries of the Region in terms of treatment and outcomes.

Emotional, neurohormonal, and hemodynamic responses to mental stress in Tako-Tsubo cardiomyopathy.

PubMed

Smeijers, Loes; Szabó, Balázs M; van Dammen, Lotte; Wonnink, Wally; Jakobs, Bernadette S; Bosch, Jos A; Kop, Willem J

2015-06-01

Tako-Tsubo cardiomyopathy (TTC) is characterized by apical ballooning of the left ventricle and symptoms and signs mimicking acute myocardial infarction. The high catecholamine levels in the acute phase of TTC and common emotional triggers suggest a dysregulated stress response system. This study examined whether patients with TTC show exaggerated emotional, neurohormonal, and hemodynamic responses to mental stress. Patients with TTC (n = 18; mean age 68.3 ± 11.7, 78% women) and 2 comparison groups (healthy controls, n = 19; mean age 60.0 ± 7.6, 68% women; chronic heart failure, n = 19; mean age 68.8 ± 10.1, 68% women) performed a structured mental stress task (anger recall and mental arithmetic) and low-grade exercise with repeated assessments of negative emotions, neurohormones (catecholamines: norepinephrine, epinephrine, dopamine, hypothalamic-pituitary-adrenal axis hormones: adrenocorticotropic hormone [ACTH], cortisol), echocardiography, blood pressure, and heart rate. TTC was associated with higher norepinephrine (520.7 ± 125.5 vs 407.9 ± 155.3 pg/ml, p = 0.021) and dopamine (16.2 ± 10.3 vs 10.3 ± 3.9 pg/ml, p = 0.027) levels during mental stress and relatively low emotional arousal (p <0.05) compared with healthy controls. During exercise, norepinephrine (511.3 ± 167.1 vs 394.4 ± 124.3 pg/ml, p = 0.037) and dopamine (17.3 ± 10.0 vs 10.8 ± 4.1 pg/ml, p = 0.017) levels were also significantly higher in patients with TTC compared with healthy controls. In conclusion, catecholamine levels during mental stress and exercise were elevated in TTC compared with healthy controls. No evidence was found for a dysregulated hypothalamic-pituitary-adrenal axis or hemodynamic responses. Patients with TTC showed blunted emotional arousal to mental stress. This study suggests that catecholamine hyper-reactivity and not emotional hyper-reactivity to stress is likely to play a role in myocardial vulnerability in TTC. Copyright © 2015 Elsevier Inc. All rights reserved.

Development, Implementation and Evaluation of an Audiotape and Accompanying Visuals in Hemodynamics as a Supplementary Teaching Aid for Human Anatomy and Physiology: Curriculum and Program Planning.

ERIC Educational Resources Information Center

Selvadurai, Ranjani H.

The purpose of this study was to develop, implement, and evaluate an audiotape and accompanying handouts on hemodynamics as a supplemental teaching aid in the Health Science Learning Center of New York City Technical College. It was hypothesized that there would be a significant difference between the mean examination grade on hemodynamics of…

[Compensatory-adaptive reactions of regional hemodynamics to weightlessness during a long space flight].

PubMed

Iarullin, Kh Kh; Vasil'eva, T D; Turchaninova, V F; Sokolova, I V; Vikharev, N D

1984-01-01

This paper discusses regional hemodynamics and vascular regulation during and after space flights of over 3 months in duration. Mechanisms of cardiovascular adaptation to weightlessness are described. The postflight differences in the recovery of regional hemodynamics seem to depend on the individual characteristics, age-related changes of the cardiovascular system, as well as the countermeasures and rehabilitation measures performed during and after flight.

[Effect of complex sanatorium treatment including magnetotherapy on hemodynamics in patients with arterial hypertension].

PubMed

Efremushkin, G G; Duruda, N V

2003-01-01

Forty nine patients with arterial hypertension of stage I-II received combined sanatorium treatment. Of them, 21 had adjuvant total magnetotherapy. All the patients were examined for parameters of central, cerebral hemodynamics and microcirculation. The adjuvant magnetotherapy produced a beneficial effect on hypertension: clinical symptoms attenuated, arterial pressure became more stable, hemodynamics improved, duration of hospitalization reduced, requirement in hypotensive drugs diminished.

[Cerebral hemodynamics in patients with neurosensory hearing loss before and after magnetotherapy].

PubMed

Morenko, V M; Enin, I P

2001-01-01

Magnetotherapy effects on cerebral hemodynamics were studied using rheoencephalography (REG). When the treatment results and changes in cerebral hemodynamics were compared it was evident that normalization or improvement of vascular status in vertebrobasilar and carotid territories registered at REG results in better hearing. This confirms the role of vascular factor in pathogenesis of neurosensory hypoacusis of different etiology and effectiveness of magnetotherapy in such patients.

Understanding neural system dynamics through task modulation and measurement of functional MRI amplitude, latency, and width

PubMed Central

Bellgowan, P. S. F.; Saad, Z. S.; Bandettini, P. A.

2003-01-01

Estimates of hemodynamic amplitude, delay, and width were combined to investigate system dynamics involved in lexical decision making. Subjects performed a lexical decision task using word and nonword stimuli rotated 0°, 60°, or 120°. Averaged hemodynamic responses to repeated stimulation were fit to a Gamma-variate function convolved with a heavyside function of varying onset and duration to estimate each voxel's activation delay and width. Consistent with prolonged reaction times for the rotated stimuli and nonwords, the motor cortex showed delayed hemodynamic onset for both conditions. Language areas such as the lingual gyrus, middle temporal gyrus, fusiform gyrus, and precuneus all showed delayed hemodynamic onsets to rotated stimuli but not to nonword stimuli. The inferior frontal gyrus showed both increased onset latency for rotated stimuli and a wider hemodynamic response to nonwords, consistent with prolonged processing in this area during the lexical decision task. Phonological processing areas such as superior temporal and angular gyrus showed no delay or width difference for rotated stimuli. These results suggest that phonological routes but not semantic routes to the lexicon can proceed regardless of stimulus orientation. This study demonstrates the utility of estimating hemodynamic delay and width in addition to amplitude allowing for more quantitative measures of brain function such as mental chronometry. PMID:12552093

Measuring hemodynamics in the developing heart tube with four-dimensional gated Doppler optical coherence tomography

NASA Astrophysics Data System (ADS)

Jenkins, Michael W.; Peterson, Lindsy; Gu, Shi; Gargesha, Madhusudhana; Wilson, David L.; Watanabe, Michiko; Rollins, Andrew M.

2010-11-01

Hemodynamics is thought to play a major role in heart development, yet tools to quantitatively assess hemodynamics in the embryo are sorely lacking. The especially challenging analysis of hemodynamics in the early embryo requires new technology. Small changes in blood flow could indicate when anomalies are initiated even before structural changes can be detected. Furthermore, small changes in the early embryo that affect blood flow could lead to profound abnormalities at later stages. We present a demonstration of 4-D Doppler optical coherence tomography (OCT) imaging of structure and flow, and present several new hemodynamic measurements on embryonic avian hearts at early stages prior to the formation of the four chambers. Using 4-D data, pulsed Doppler measurements could accurately be attained in the inflow and outflow of the heart tube. Also, by employing an en-face slice from the 4-D Doppler image set, measurements of stroke volume and cardiac output are obtained without the need to determine absolute velocity. Finally, an image plane orthogonal to the blood flow is used to determine shear stress by calculating the velocity gradient normal to the endocardium. Hemodynamic measurements will be crucial to identifying genetic and environmental factors that lead to congenital heart defects.

Combining near-infrared spectroscopy with electroencephalography and repetitive transcranial magnetic stimulation

NASA Astrophysics Data System (ADS)

Näsi, Tiina; Kotilahti, Kalle; Mäki, Hanna; Nissilä, Ilkka; Meriläinen, Pekka

2009-07-01

The objective of the study was to assess the usability of a near-infrared spectroscopy (NIRS) device in multimodal measurements. We combined NIRS with electroencephalography (EEG) to record hemodynamic responses and evoked potentials simultaneously, and with transcranial magnetic stimulation (TMS) to investigate hemodynamic responses to repetitive TMS (rTMS). Hemodynamic responses and visual evoked potentials (VEPs) to 3, 6, and 12 s stimuli consisting of pattern-reversing checkerboards were successfully recorded in the NIRS/EEG measurement, and ipsi- and contralateral hemodynamic responses to 0.5, 1, and 2 Hz rTMS in the NIRS/TMS measurement. In the NIRS/EEG measurements, the amplitudes of the hemodynamic responses increased from 3- to 6-s stimulus, but not from 6- to 12-s stimulus, and the VEPs showed peaks N75, P100, and N135. In the NIRS/TMS measurements, the 2-Hz stimulus produced the strongest hemodynamic responses compared to the 0.5- and 1-Hz stimuli. In two subjects oxyhemoglobin concentration decreased and in one increased as a consequence of the 2-Hz rTMS. To locate the origin of the measured NIRS responses, methods have to be developed to investigate TMS-induced scalp muscle contractions. In the future, multimodal measurements may prove useful in monitoring or treating diseases such as stroke or Alzheimer's disease.

Hemodynamic Response Alteration As a Function of Task Complexity and Expertise—An fNIRS Study in Jugglers

PubMed Central

Carius, Daniel; Andrä, Christian; Clauß, Martina; Ragert, Patrick; Bunk, Michael; Mehnert, Jan

2016-01-01

Detailed knowledge about online brain processing during the execution of complex motor tasks with a high motion range still remains elusive. The aim of the present study was to investigate the hemodynamic responses within sensorimotor networks as well as in visual motion area during the execution of a complex visuomotor task such as juggling. More specifically, we were interested in how far the hemodynamic response as measured with functional near infrared spectroscopy (fNIRS) adapts as a function of task complexity and the level of the juggling expertise. We asked expert jugglers to perform different juggling tasks with different levels of complexity such as a 2-ball juggling, 3- and 5-ball juggling cascades. We here demonstrate that expert jugglers show an altered neurovascular response with increasing task complexity, since a 5-ball juggling cascade showed enhanced hemodynamic responses for oxygenated hemoglobin as compared to less complex tasks such as a 3- or 2-ball juggling pattern. Moreover, correlations between the hemodynamic response and the level of the juggling expertise during the 5-ball juggling cascade, acquired by cinematographic video analysis, revealed only a non-significant trend in primary motor cortex, indicating that a higher level of expertise might be associated with lower hemodynamic responses. PMID:27064925

Gender-specific hemodynamics in prefrontal cortex during a verbal working memory task by near-infrared spectroscopy.

PubMed

Li, Ting; Luo, Qingming; Gong, Hui

2010-05-01

The presence or absence of gender differences in working memory, localized in the prefrontal cortex (PFC), has been debated in a few fMRI studies. However, the hypothesis of gender differences in PFC function has not been elaborated, and comparisons among hemodynamic parameters designed to test for gender differences are scarce. We utilized near-infrared spectroscopy during verbal N-back tasks on 26 male and 24 female healthy volunteers. Changes in the concentrations of oxy- (Delta[oxy-Hb]), deoxy- (Delta[deoxy-Hb]) and total hemoglobin (Delta[tot-Hb]) were recorded simultaneously. Delta[oxy-Hb] and Delta[tot-Hb] exhibited obvious gender differences, but Delta[deoxy-Hb] did not. Males showed bilateral activation with slight left-side dominance, whereas females showed left activation. The activation in males was more wide-spread and stronger than in females. Furthermore, females required a lower hemodynamic supply than males to obtain comparable performance, and only females exhibited positive correlations between hemodynamic parameters and behavioral performance. The results reinforce the existence of a gender effect in hemodynamic-based functional imaging studies. Our findings suggest that females possess more efficient hemodynamics in the PFC during working memory and emphasize the importance of studying the PFC to further a scientific understanding of gender differences.

Self-reported tolerance influences prefrontal cortex hemodynamics and affective responses.

PubMed

Tempest, Gavin; Parfitt, Gaynor

2016-02-01

The relationship between cognitive and sensory processes in the brain contributes to the regulation of affective responses (pleasure-displeasure). Exercise can be used to manipulate sensory processes (by increasing physiological demand) in order to examine the role of dispositional traits that may influence an individual's ability to cognitively regulate these responses. With the use of near infrared spectroscopy, in this study we examined the influence of self-reported tolerance upon prefrontal cortex (PFC) hemodynamics and affective responses. The hemodynamic response was measured in individuals with high or low tolerance during an incremental exercise test. Sensory manipulation was standardized against metabolic processes (ventilatory threshold [VT] and respiratory compensation point [RCP]), and affective responses were recorded. The results showed that the high-tolerance group displayed a larger hemodynamic response within the right PFC above VT (which increased above RCP). The low-tolerance group showed a larger hemodynamic response within the left PFC above VT. The high-tolerance group reported a more positive/less negative affective response above VT. These findings provide direct neurophysiological evidence of differential hemodynamic responses within the PFC that are associated with tolerance in the presence of increased physiological demands. This study supports the role of dispositional traits and previous theorizing into the underlying mechanisms (cognitive vs. sensory processes) of affective responses.

Association between hemodynamic activity and motor performance in six-month-old full-term and preterm infants: a functional near-infrared spectroscopy study.

PubMed

de Oliveira, Suelen Rosa; de Paula Machado, Ana Carolina Cabral; de Paula, Jonas Jardim; de Moraes, Paulo Henrique Paiva; Nahin, Maria Juliana Silvério; Magalhães, Lívia de Castro; Novi, Sergio L; Mesquita, Rickson C; de Miranda, Débora Marques; Bouzada, Maria Cândida Ferrarez

2018-01-01

This study aimed to assess task-induced activation in motor cortex and its association with motor performance in full-term and preterm born infants at six months old. A cross-sectional study of 73 six-month-old infants was conducted (35 full-term and 38 preterm infants). Motor performance was assessed using the Bayley Scales of Infant Development third edition-Bayley-III. Brain hemodynamic activity during motor task was measured by functional near-infrared spectroscopy (fNIRS). Motor performance was similar in full-term and preterm infants. However, differences in hemodynamic response were identified. Full terms showed a more homogeneous unilateral and contralateral activated area, whereas in preterm-born the activation response was predominantly bilateral. The full-term group also exhibited a shorter latency for the hemodynamic response than the preterm group. Hemodynamic activity in the left sensorimotor region was positively associated with motor performance measured by Bayley-III. The results highlight the adequacy of fNIRS to assess differences in task-induced activation in sensorimotor cortex between groups. The association between motor performance and the hemodynamic activity require further investigation and suggest that fNIRS can become a suitable auxiliary tool to investigate aspects of neural basis on early development of motor abilities.

Saturation thresholds of evoked neural and hemodynamic responses in awake and asleep rats

NASA Astrophysics Data System (ADS)

Schei, Jennifer L.; Van Nortwick, Amy S.; Meighan, Peter C.; Rector, David M.

2011-03-01

Neural activation generates a hemodynamic response to the localized region replenishing nutrients to the area. Changes in vigilance state have been shown to alter the vascular response where the vascular response is muted during wake compared to quiet sleep. We tested the saturation thresholds of the neurovascular response in the auditory cortex during wake and sleep by chronically implanting rats with an EEG electrode, a light emitting diode (LED, 600 nm), and photodiode to simultaneously measure evoked response potentials (ERPs) and evoked hemodynamic responses. We stimulated the cortex with a single speaker click delivered at random intervals 2-13 s at varied stimulus intensities ranging from 45-80 dB. To further test the potential for activity related saturation, we sleep deprived animals for 2, 4, or 6 hours and recorded evoked responses during the first hour recovery period. With increasing stimulus intensity, integrated ERPs and evoked hemodynamic responses increased; however the hemodynamic response approached saturation limits at a lower stimulus intensity than the ERP. With longer periods of sleep deprivation, the integrated ERPs did not change but evoked hemodynamic responses decreased. There may be physical limits in cortical blood delivery and vascular compliance, and with extended periods of neural activity during wake, vessels may approach these limits.

Effect of programmed intermittent epidural boluses and continuous epidural infusion on labor analgesia and obstetric outcomes: a randomized controlled trial.

PubMed

Ferrer, Leopoldo E; Romero, David J; Vásquez, Oscar I; Matute, Ednna C; Van de Velde, Marc

2017-11-01

Continuous epidural infusion and programmed intermittent epidural boluses are analgesic techniques routinely used for pain relief in laboring women. We aimed to assess both techniques and compare them with respect to labor analgesia and obstetric outcomes. After Institutional Review Board approval, 132 laboring women aged between 18 and 45 years were randomized to epidural analgesia of 10 mL of a mixture of 0.1% bupivacaine plus 2 µg/mL of fentanyl either by programmed intermittent boluses or continuous infusion (66 per group). Primary outcome was quality of analgesia. Secondary outcomes were duration of labor, total drug dose used, maternal satisfaction, sensory level, motor block level, presence of unilateral motor block, hemodynamics, side effects, mode of delivery, and newborn outcome. Patients in the programmed intermittent epidural boluses group received statistically less drug dose than those with continuous epidural infusion (24.9 vs 34.4 mL bupivacaine; P = 0.01). There was no difference between groups regarding pain control, characteristics of block, hemodynamics, side effects, and Apgar scores. Our study evidenced a lower anesthetic consumption in the programmed intermittent boluses group with similar labor analgesic control, and obstetric and newborn outcomes in both groups.

Intermittent levosimendan infusions in advanced heart failure: favourable effects on left ventricular function, neurohormonal balance, and one-year survival.

PubMed

Malfatto, Gabriella; Della Rosa, Francesco; Villani, Alessandra; Rella, Valeria; Branzi, Giovanna; Facchini, Mario; Parati, Gianfranco

2012-11-01

The role of repeated infusions of Levosimendan (LEVO) in patients with chronic advanced heart failure is still unclear. Thirty-three patients with chronic heart failure presenting clinical deterioration were randomized 2:1 to receive monthly infusions of LEVO (n = 22) or Furosemide (Controls, n = 11). At the first drug's administration, noninvasive hemodynamic evaluation was performed; before and after each infusion, we assessed NYHA class, systolic and diastolic function, functional mitral regurgitation, and brain natriuretic peptide (BNP) levels. Noninvasive hemodynamic in the LEVO group showed vasodilation and decrease in thoracic conductance (index of pulmonary congestion), whereas in Controls, only a reduced thoracic conductance was observed. In the LEVO group, systolic and diastolic function, ventricular volumes, severity of mitral regurgitation, and BNP levels improved over time from baseline and persisted 4 weeks after the last infusion (P < 0.01). In Controls, no change developed over time in cardiac function and BNP levels. In LEVO-treated patients, 1-year mortality tended to be lower than in those treated with Furosemide. In conclusion, serial LEVO infusions in advanced heart failure improved ventricular performance and favorably modulated neurohormonal activation. Multicenter randomized studies are warranted to test the effect of LEVO on long-term outcome.

Abnormal Neurocirculatory Control During Exercise in Humans with Chronic Renal Failure

PubMed Central

Park, Jeanie; Middlekauff, Holly R.

2014-01-01

Abnormal neurocirculatory control during exercise is one important mechanism leading to exercise intolerance in patients with both end-stage renal disease (ESRD) and earlier stages of chronic kidney disease (CKD). This review will provide an overview of mechanisms underlying abnormal neurocirculatory and hemodynamic responses to exercise in patients with kidney disease. Recent studies have shown that ESRD and CKD patients have an exaggerated increase in blood pressure (BP) during both isometric and rhythmic exercise. Subsequent studies examining the role of the exercise pressor reflex in the augmented pressor response revealed that muscle sympathetic nerve activity (MSNA) was not augmented during exercise in these patients, and metaboreflex-mediated increases in MSNA were blunted, while mechanoreflex-mediated increases were preserved under basal conditions. However, normalizing the augmented BP response during exercise via infusion of nitroprusside (NTP), and thereby equalizing baroreflex-mediated suppression of MSNA, an important modulator of the final hemodynamic response to exercise, revealed that CKD patients had an exaggerated increase in MSNA during isometric and rhythmic exercise. In addition, mechanoreflex-mediated control was augmented, and metaboreceptor blunting was no longer apparent in CKD patients with baroreflex normalization. Factors leading to mechanoreceptor sensitization, and other mechanisms underlying the exaggerated exercise pressor response, such as impaired functional sympatholysis, should be investigated in future studies. PMID:25458430

Prefrontal responses to digit span memory phases in patients with post-traumatic stress disorder (PTSD): a functional near infrared spectroscopy study.

PubMed

Tian, Fenghua; Yennu, Amarnath; Smith-Osborne, Alexa; Gonzalez-Lima, F; North, Carol S; Liu, Hanli

2014-01-01

Neuroimaging studies of post-traumatic stress disorder (PTSD)-related memory impairments have consistently implicated abnormal activities in the frontal and parietal lobes. However, most studies have used block designs and could not dissociate the multiple phases of working memory. In this study, the involvement of the prefrontal cortex in working memory phases was assessed among veterans with PTSD and age-/gender-matched healthy controls. Multichannel functional near infrared spectroscopy (fNIRS) was utilized to measure prefrontal cortex hemodynamic activations during memory of neutral (i.e., not trauma-related) forward and backward digit span tasks. An event-related experimental design was utilized to dissociate the different phases (i.e., encoding, maintenance and retrieval) of working memory. The healthy controls showed robust hemodynamic activations during the encoding and retrieval processes. In contrast, the veterans with PTSD were found to have activations during the encoding process, but followed by distinct deactivations during the retrieval process. The PTSD participants, but not the controls, appeared to suppress prefrontal activity during memory retrieval. This deactivation was more pronounced in the right dorsolateral prefrontal cortex during the retrieval phase. These deactivations in PTSD patients might implicate an active inhibition of dorsolateral prefrontal neural activity during retrieval of working memory.

Coronary Blood Flow Is Increased in RV Hypertrophy, but the Shape of Normalized Waves Is Preserved Throughout the Arterial Tree.

PubMed

Huo, Yunlong; Kassab, Ghassan S

2018-01-01

A pulsatile hemodynamic analysis was carried out in the right coronary arterial (RCA) tree of control and RV hypertrophy (RVH) hearts. The shape of flow and wall shear stress (WSS) waves was hypothesized to be maintained throughout the RCA tree in RVH (i.e., similar patterns of normalized flow and WSS waves in vessels of various sizes). Consequently, we reconstructed the entire RCA tree down to the first capillary bifurcation of control and RVH hearts based on measured morphometric data. A Womersley-type model was used to compute the flow and WSS waves in the tree. The hemodynamic parameters obtained from experimental measurements were incorporated into the numerical model. Given an increased number of arterioles, the mean and amplitude of flow waves at the inlet of RCA tree in RVH was found to be two times larger than that in control, but no significant differences ( p > 0.05) were found in precapillary arterioles. The increase of stiffness in RCA of RVH preserved the shape of normalized flow and WSS waves, but increased the PWV in coronary arteries and reduced the phase angle difference for the waves between the most proximal RCA and the most distal precapillary arteriole. The study is important for understanding pulsatile coronary blood flow in ventricular hypertrophy.

Direct cortical hemodynamic mapping of somatotopy of pig nostril sensation by functional near-infrared cortical imaging (fNCI).

PubMed

Uga, Minako; Saito, Toshiyuki; Sano, Toshifumi; Yokota, Hidenori; Oguro, Keiji; Rizki, Edmi Edison; Mizutani, Tsutomu; Katura, Takusige; Dan, Ippeita; Watanabe, Eiju

2014-05-01

Functional near-infrared spectroscopy (fNIRS) is a neuroimaging technique for the noninvasive monitoring of human brain activation states utilizing the coupling between neural activity and regional cerebral hemodynamics. Illuminators and detectors, together constituting optodes, are placed on the scalp, but due to the presence of head tissues, an inter-optode distance of more than 2.5cm is necessary to detect cortical signals. Although direct cortical monitoring with fNIRS has been pursued, a high-resolution visualization of hemodynamic changes associated with sensory, motor and cognitive neural responses directly from the cortical surface has yet to be realized. To acquire robust information on the hemodynamics of the cortex, devoid of signal complications in transcranial measurement, we devised a functional near-infrared cortical imaging (fNCI) technique. Here we demonstrate the first direct functional measurement of temporal and spatial patterns of cortical hemodynamics using the fNCI technique. For fNCI, inter-optode distance was set at 5mm, and light leakage from illuminators was prevented by a special optode holder made of a light-shielding rubber sheet. fNCI successfully detected the somatotopy of pig nostril sensation, as assessed in comparison with concurrent and sequential somatosensory-evoked potential (SEP) measurements on the same stimulation sites. Accordingly, the fNCI system realized a direct cortical hemodynamic measurement with a spatial resolution comparable to that of SEP mapping on the rostral region of the pig brain. This study provides an important initial step toward realizing functional cortical hemodynamic monitoring during neurosurgery of human brains. Copyright © 2014. Published by Elsevier Inc.

Right ventricular dysfunction as an echocardiographic prognostic factor in hemodynamically stable patients with acute pulmonary embolism: a meta-analysis.

PubMed

Cho, Jae Hyung; Kutti Sridharan, Gurusaravanan; Kim, Seon Ha; Kaw, Roop; Abburi, Triveni; Irfan, Affan; Kocheril, Abraham G

2014-05-06

We investigated whether right ventricular dysfunction (RVD) as assessed by echocardiogram can be used as a prognostic factor in hemodynamically stable patients with acute pulmonary embolism (PE). Short-term mortality has been investigated only in small studies and the results have been controversial. A PubMed search was conducted using two keywords, "pulmonary embolism" and "echocardiogram", for articles published between January 1st 1998 and December 31st 2011. Out of 991 articles, after careful review, we found 12 articles that investigated the implications of RVD as assessed by echocardiogram in predicting short-term mortality for hemodynamically stable patients with acute PE. We conducted a meta-analysis of these data to identify whether the presence of RVD increased short-term mortality. Among 3283 hemodynamically stable patients with acute PE, 1223 patients (37.3%) had RVD, as assessed by echocardiogram, while 2060 patients (62.7%) had normal right ventricular function. Short-term mortality was reported in 167 (13.7%) out of 1223 patients with RVD and in 134 (6.5%) out of 2060 patients without RVD. Hemodynamically stable patients with acute PE who had RVD as assessed by echocardiogram had a 2.29-fold increase in short-term mortality (odds ratio 2.29, 95% confidence interval 1.61-3.26) compared with patients without RVD. In hemodynamically stable patients with acute PE, RVD as assessed by echocardiogram increases short-term mortality by 2.29 times. Consideration should be given to obtaining echocardiogram to identify high-risk patients even if they are hemodynamically stable.

Brain and muscle oxygenation monitoring using near-infrared spectroscopy (NIRS) during all-night sleep

NASA Astrophysics Data System (ADS)

Zhang, Zhongxing; Khatami, Ramin

2013-03-01

The hemodynamic changes during natural human sleep are still not well understood. NIRS is ideally suited for monitoring the hemodynamic changes during sleep due to the properties of local measurement, totally safe application and good tolerance to motion. Several studies have been conducted using NIRS in both normal subjects and patients with various sleep disorders during sleep to characterize the hemodynamic changing patterns during different sleep stages and during different symptoms such as obstructive apneas. Here we assessed brain and muscle oxygenation changes in 7 healthy adults during all-night sleep with combined polysomnography measurement to test the notion if hemodynamic changes in sleep are indeed brain specific. We found that muscle and brain showed similar hemodynamic changes during sleep initiation. A decrease in HbO2 and tissue oxygenation index (TOI) while an increase in HHb was observed immediately after sleep onset, and an opposite trend was found after transition with progression to deeper slow-wave sleep (SWS) stage. Spontaneous low frequency oscillations (LFO) and very low frequency oscillations (VLFO) were smaller (Levene's test, p<0.05) during SWS compared to light sleep (LS) and rapid-eye-movement (REM) sleep in both brain and muscle. Spectral analysis of the NIRS signals measured from brain and muscle also showed reductions in VLFO and LFO powers during SWS with respect to LS and REM sleep. These results indicate a systemic attenuation rather than local cerebral reduction of spontaneous hemodynamic activity in SWS. A systemic physiological mechanism may exist to regulate the hemodynamic changes in brain and muscle during sleep.

Hemodynamics of Pericardial Aortic Valves: Contemporary Stented versus Stentless Valves in a Matched Comparison

PubMed Central

Holinski, Sebastian; Zhigalov, Konstantin; Zielinski, Christina Barbara; Grubitzsch, Herko

2017-01-01

Purpose: Hemodynamic performance of aortic valve bioprostheses is essential for reliable function and durability. So far, the supra-annularly implanted stentless Sorin Freedom Solo (SFS) demonstrated unsurpassed hemodynamic properties. As contemporary stented and externally mounted pericardial bioprostheses, like the Labcor Dokimos Plus (LDP), also improve hemodynamic performance, these types of valves were compared in this study. Methods: A total of 218 patients, who underwent aortic valve replacement with the LDP or the SFS, were matched retrospectively 1:1 on variables affecting hemodynamic measurements: implanted valve size, age, sex, and body surface area (BSA). With matching tolerance for valve size and gender of 0%, for age and BSA of 5%, 57 patient-pairs were yielded. Operative data, clinical, and hemodynamic outcome were analyzed. Results: Except for slightly higher left ventricular function and lower procedural times in the SFS group, preoperative, operative, and postoperative characteristics of patient-pairs did not differ significantly. Mean pressure gradients, effective orifice areas (EOAs), and indexed EOAs were comparable. Corresponding to valve sizes of 21, 23, 25, and 27 mm, the indexed EOAs of the LDP and SFS prostheses were 1.08 ± 0.33, 0.92 ± 0.19, 0.93 ± 0.24, 0.99 ± 0.13 cm2/m2 and 0.81 ± 0.13, 0.92 ± 0.28, 0.95 ± 0.20, 1.04 ± 0.27 cm2/m2, respectively. Conclusion: Contemporary stented and stentless pericardial bioprostheses showed excellent hemodynamic properties without significant differences in EOAs and indexed EOAs. PMID:28890465

Role of aminophylline in refractory heart failure: a comparison to the vasodilator sodium nitroprusside, the old and the new.

PubMed

DiBianco, R; Rosenfeld, S P; Katz, R J; Simpson, A G; Fletcher, R D; Singh, S

1980-08-01

Aminophylline [(theophylline ethylene diamine (TED)] reportedly improved cardiac hemodynamics by lowering vascular resistances and increasing contractility. TED as used clinically has not been compared to the vasodilator sodium nitroprusside (NP). To assess the relative hemodynamic effects of these two commonly used agents, the following comparison was made. Ten patients with congestive cardiomyopathy in chronic refractory heart failure [New York Heart Association (NYHA) class IV] were studied. All patients demonstrated cardiomegaly by chest x ray and echocardiography (LVd = 6.3 +/- 0.7 cm) and markedly abnormal hemodynamics during baseline observations (see Table I). Hemodynamic measurements at baseline were compared after TED infusion (mean blood level = 16 +/- 12 micrograms/m/TED) and during intravenous NP. No significant changes in heart rate occurred during either therapeutic intervention; a fall in mean arterial pressure of 10 mmHg (p < 0.01) was observed during NP therapy; atrioventricular (AV) block with ventricular fibrillation was successfully treated in one patient after TED. Theophylline ethylene diamine demonstrated no detectable cardiac hemodynamic effects 60--90 min post infusion despite proven blood levels, whereas NP exhibited distinctly beneficial effects in this patient group. Previous studies demonstrating improved hemodynamics occurring with TED have been limited to the time of infusion or within the following 40 min, a time when TED blood levels are maximum and therefore closest to toxicity. The results of this study suggest that TED demonstrates no beneficial hemodynamic effects in refractory heart failure as early as 1 h after infusion despite blood levels in the therapeutic range.

Optical mapping of brain activation in gambling disorders

NASA Astrophysics Data System (ADS)

Yuan, Zhen; Lin, Xiaohong

2018-02-01

In this study, fNIRS was utilized to identify the brain activation difference between pathological gamblers (PGs) and heathy controls (HCs). We inspected the hemodynamic changes in the prefrontal cortex using fNIRS recordings during the completion of executive function and decision making tasks. Our finding revealed that the PG and HC groups exhibited significant differences in brain activation.

Characterization of Common Measures of Heart Period Variability in Healthy Human Subjects: Implications for Patient Monitoring

DTIC Science & Technology

2010-01-01

application of these metrics to patient monitoring must take into account the impact of other external stimuli, such as pain, anxiety and activity status...in short-term HRV analysis. Biomed Tech 2006; 51: 190–193. 45. Hayano J, Taylor JA, Yamada A, et al. Continuous assessment of hemodynamic control by

Hemodynamic characterization of geometric cerebral aneurysm templates.

PubMed

Nair, Priya; Chong, Brian W; Indahlastari, Aprinda; Lindsay, James; DeJeu, David; Parthasarathy, Varsha; Ryan, Justin; Babiker, Haithem; Workman, Christopher; Gonzalez, L Fernando; Frakes, David

2016-07-26

Hemodynamics are currently considered to a lesser degree than geometry in clinical practices for evaluating cerebral aneurysm (CA) risk and planning CA treatment. This study establishes fundamental relationships between three clinically recognized CA geometric factors and four clinically relevant hemodynamic responses. The goal of the study is to develop a more combined geometric/hemodynamic basis for informing clinical decisions. Flows within eight idealized template geometries were simulated using computational fluid dynamics and measured using particle image velocimetry under both steady and pulsatile flow conditions. The geometric factor main effects were then analyzed to quantify contributions made by the geometric factors (aneurysmal dome size (DS), dome-to-neck ratio (DNR), and parent-vessel contact angle (PV-CA)) to effects on the hemodynamic responses (aneurysmal and neck-plane root-mean-square velocity magnitude (Vrms), aneurysmal wall shear stress (WSS), and cross-neck flow (CNF)). Two anatomical aneurysm models were also examined to investigate how well the idealized findings would translate to more realistic CA geometries. DNR made the greatest contributions to effects on hemodynamics including a 75.05% contribution to aneurysmal Vrms and greater than 35% contributions to all responses. DS made the next greatest contributions, including a 43.94% contribution to CNF and greater than 20% contributions to all responses. PV-CA and several factor interactions also made contributions of greater than 10%. The anatomical aneurysm models and the most similar idealized templates demonstrated consistent hemodynamic response patterns. This study demonstrates how individual geometric factors, and combinations thereof, influence CA hemodynamics. Bridging the gap between geometry and flow in this quantitative yet practical way may have potential to improve CA evaluation and treatment criteria. Agreement among results from idealized and anatomical models further supports the potential for a template-based approach to play a useful role in clinical practice. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Effectiveness of various dopamine doses in acute myocardial ischemia complicated by cardiogenic shock (an experimental study)].

PubMed

Kipshidze, N N; Korotkov, A A; Marsagishvili, L A; Prigolashvili, T Sh; Bokhua, M R

1981-06-01

The effect of various doses of dopamine on the values of cardiac contractile and hemodynamic function under conditions of acute two-hour ischemia complicated by cardiogenic shock was studied in 27 experiments on dogs. In a dose of 5 microgram/kg/min dopamine caused an optimum increase in cardiac productive capacity, reduction of peripheral resistance, adequate increase in coronary circulation and decrease in ST segment depression on the ECG. Infusion of 10 microgram/kg/min dopamine usually caused myocardial hyperfunction with an increase in total peripheral resistance and cardiac performance. Maximum dopamine doses (10 microgram/kg/min and more) were effective in the areactive form of cardiogenic shock. In longterm dopamine infusion it is necessary to establish continuous control over the hemodynamic parameters and the ECG to prevent aggravation of ischemia and for stage-by-stage reduction of the drug concentration and determination of the minimum maintenance dose.

[Results of the use of pumpan preparation in the treatment of severe forms of angina pectoris].

PubMed

Parshina, S S; Golovacheva, T V; Afanas'eva, T N; Panchenko, O V; Baldina, A A; Starostina, N V; Lial'chenko, I F; Egorova, L P

2000-01-01

To assess validity of adjuvant use of pumpan, a homeopathic compound, in patients with unstable angina pectoris and angina of effort (functional class III-IV) receiving conventional treatment. A direct open controlled trial for 15 months performed initially in hospital, then outpatiently, covered 49 patients with severe angina. Examination of the patients included evaluation of clinical condition and the disease course, lipid metabolism, hemostasis, blood plasma electrolytes, aminotransferases, echo-CG, bicycle exercise, rheoencephalography, ultrasonic dopplerography of head and neck vessels. Pumpan produced a positive effect total nonspecific systemic resistance improved, number of hospitalizations reduced, intracardiac hemodynamics improved in some cases with severe angina. Homeopathic compound pumpan can be recommended in the treatment of severe angina to reinforce antianginal effect, improve the disease clinical course, to obtain a hypocoagulative and hypocholesterolemic effect, to normalize intracardiac hemodynamics, to raise myocardial performance and intracoronary reserve as well as nonspecific resistance of the body.

Neural Processing of Facial Identity and Emotion in Infants at High-Risk for Autism Spectrum Disorders

PubMed Central

Fox, Sharon E.; Wagner, Jennifer B.; Shrock, Christine L.; Tager-Flusberg, Helen; Nelson, Charles A.

2013-01-01

Deficits in face processing and social impairment are core characteristics of autism spectrum disorder. The present work examined 7-month-old infants at high-risk for developing autism and typically developing controls at low-risk, using a face perception task designed to differentiate between the effects of face identity and facial emotions on neural response using functional Near-Infrared Spectroscopy. In addition, we employed independent component analysis, as well as a novel method of condition-related component selection and classification to identify group differences in hemodynamic waveforms and response distributions associated with face and emotion processing. The results indicate similarities of waveforms, but differences in the magnitude, spatial distribution, and timing of responses between groups. These early differences in local cortical regions and the hemodynamic response may, in turn, contribute to differences in patterns of functional connectivity. PMID:23576966

Understanding the physiology of mindfulness: aortic hemodynamics and heart rate variability.

PubMed

May, Ross W; Bamber, Mandy; Seibert, Gregory S; Sanchez-Gonzalez, Marcos A; Leonard, Joseph T; Salsbury, Rebecca A; Fincham, Frank D

2016-01-01

Data were collected to examine autonomic and hemodynamic cardiovascular modulation underlying mindfulness from two independent samples. An initial sample (N = 185) underwent laboratory assessments of central aortic blood pressure and myocardial functioning to investigated the association between mindfulness and cardiac functioning. Controlling for religiosity, mindfulness demonstrated a strong negative relationship with myocardial oxygen consumption and left ventricular work but not heart rate or blood pressure. A second sample (N = 124) underwent a brief (15 min) mindfulness inducing intervention to examine the influence of mindfulness on cardiovascular autonomic modulation via blood pressure variability and heart rate variability. The intervention had a strong positive effect on cardiovascular modulation by decreasing cardiac sympathovagal tone, vasomotor tone, vascular resistance and ventricular workload. This research establishes a link between mindfulness and cardiovascular functioning via correlational and experimental methodologies in samples of mostly female undergraduates. Future directions for research are outlined.

Renal responses to central vascular expansion are suppressed at night in conscious primates

NASA Technical Reports Server (NTRS)

Kass, D. A.; Sulzman, F. M.; Fuller, C. A.; Moore-Ede, M. C.

1980-01-01

The renal and hemodynamic responses of squirrel monkeys to central vascular volume expansion induced by lower body positive pressure (LBPP) during the day and night are investigated. Twelve unanesthetized animals trained to sit in a metabolism chair in which they were restrained only at the waist by a partition separating upper and lower body chambers were subjected to 4 h of continuous LBPP during the day and night, and hemodynamic, urinary and drinking data were monitored. LBPP during day and night is found to induce similar increases in central venous pressure, rises in heart rate and elevations in mean arterial blood pressure. However, although daytime LBPP induced a significant increase in urine flow and sodium excretion, a marked nocturnal inhibition of the renal response to LBPP is observed. Analysis of the time course and circadian regulation patterns of the urinary responses suggests that several separate efferent control pathways are involved.

Imagery use and affective responses during exercise: an examination of cerebral hemodynamics using near-infrared spectroscopy.

PubMed

Tempest, Gavin; Parfitt, Gaynor

2013-10-01

Imagery, as a cognitive strategy, can improve affective responses during moderate-intensity exercise. The effects of imagery at higher intensities of exercise have not been examined. Further, the effect of imagery use and activity in the frontal cortex during exercise is unknown. Using a crossover design (imagery and control), activity of the frontal cortex (reflected by changes in cerebral hemodynamics using near-infrared spectroscopy) and affective responses were measured during exercise at intensities 5% above the ventilatory threshold (VT) and the respiratory compensation point (RCP). Results indicated that imagery use influenced activity of the frontal cortex and was associated with a more positive affective response at intensities above VT, but not RCP to exhaustion (p < .05). These findings provide direct neurophysiological evidence of imagery use and activity in the frontal cortex during exercise at intensities above VT that positively impact affective responses.

Basic equipment requirements for hemodynamic monitoring.

PubMed Central

Morton, B C

1979-01-01

Hemodynamic monitoring in the critically ill patient requires the use of sophisticated electronic devices. To use this equipment one should have a general understanding of the principles involved and the requirements of a reliable system. This communication serves to explain the requirements of the various components of a hemodynamic monitoring system and to demonstrate how they interact to produce accurate and safe electronic signals from mechanical wave forms obtained from the patient. Images FIG. 5 PMID:497978

A Revised Hemodynamic Theory of Age-Related Macular Degeneration

PubMed Central

Gelfand, Bradley D.; Ambati, Jayakrishna

2016-01-01

Age-related macular degeneration (AMD) afflicts one out of every 40 individuals worldwide, causing irreversible central blindness in millions. The transformation of various tissue layers within the macula in the retina has led to competing conceptual models of the molecular pathways, cell types, and tissues responsible for the onset and progression of AMD. A model that has persisted for over 6 decades is the hemodynamic, or vascular theory of AMD progression, which states that vascular dysfunction of the choroid underlies AMD pathogenesis. Here, we re-evaluate this hypothesis in light of recent advances on molecular, anatomic, and hemodynamic changes underlying choroidal dysfunction in AMD. We propose an updated, detailed model of hemodynamic dysfunction as a mechanism of AMD development and progression. PMID:27423265

The numerical simulation study of hemodynamics of the new dense-mesh stent

NASA Astrophysics Data System (ADS)

Ma, Jiali; Yuan, Zhishan; Yu, Xuebao; Feng, Zhaowei; Miao, Weidong; Xu, Xueli; Li, Juntao

2017-09-01

The treatment of aortic aneurysm in new dense mesh stent is based on the principle of hemodynamic changes. But the mechanism is not yet very clear. This paper analyzed and calculated the hemodynamic situation before and after the new dense mesh stent implanting by the method of numerical simulation. The results show the dense mesh stent changed and impacted the blood flow in the aortic aneurysm. The changes include significant decrement of blood velocity, pressure and shear forces, while ensuring blood can supply branches, which means the new dense mesh stent's hemodynamic mechanism in the treatment of aortic aneurysm is clearer. It has very important significance in developing new dense mesh stent in order to cure aortic aneurysm.

Profound Obstructive Hypotension From Prone Positioning Documented by Transesophageal Echocardiography in a Patient With Scoliosis: A Case Report.

PubMed

Abcejo, Arnoley S; Diaz Soto, Juan; Castoro, Courtney; Armour, Sarah; Long, Timothy R

2017-08-01

In a healthy 12-year-old female with scoliosis, prone positioning resulted in pressor-refractory cardiovascular collapse. Resumption of supine position immediately improved hemodynamics. Intraoperative transesophageal echocardiography (TEE) revealed a collapsed left atrium and biventricular failure. Repeat prone positioning resulted in a recurrence of hypotension. However, hemodynamic stabilization was restored and maintained by repositioning chest pads caudally. The patient successfully underwent a 6-hour scoliosis repair without perioperative morbidity. With this case, we aim to: (1) reintroduce awareness of this mechanical obstructive cause of reversible hypotension; (2) highlight the use of intraoperative TEE during prone hemodynamic collapse; and (3) suggest an alternative prone positioning technique if chest compression results in hemodynamic instability.

The nursing perspective on monitoring hemodynamics and oxygen transport.

PubMed

Tucker, Dawn; Hazinski, Mary Fran

2011-07-01

Maintenance of adequate systemic oxygen delivery requires careful clinical assessment integrated with hemodynamic measurements and calculations to detect and treat conditions that may compromise oxygen delivery and lead to life-threatening shock, respiratory failure, or cardiac arrest. The bedside nurse constantly performs such assessments and measurements to detect subtle changes and trends in patient condition. The purpose of this editorial is to highlight nursing perspectives about the hemodynamic and oxygen transport monitoring systems summarized in the Pediatric Cardiac Intensive Care Society Evidence- Based Review and Consensus Statement on Monitoring of Hemodynamics and Oxygen Transport Balance. There is no substitute for the observations of a knowledgeable and experienced clinician who understands the patient's condition and potential causes of deterioration and is able to evaluate response to therapy.

CFD Modelling of Local Hemodynamics in Intracranial Aneurysms Harboring Arterial Branches.

PubMed

Krylov, Vladimir; Grigoryeva, Elena; Dolotova, Daria; Blagosklonova, Evgenia; Gavrilov, Andrey

2017-01-01

The main cause of non-traumatic subarachnoid haemorrhage is an intracranial aneurysm's rupture. The choice of treatment approach is exceptionally difficult in cases of aneurysms with additional branches on the aneurysm's dome or neck. The impact of the arterial branches on local hemodynamics is still unclear and controversial question. At the same time, up-to-date methods of image processing and mathematical modeling provide a way to investigate the hemodynamic environment of aneurysms. The paper discusses hemodynamic aspects of aneurysms harboring arterial branch through the use of patient-specific 3D models and computational fluid dynamics (CFD) methods. The analysis showed that the presence of the arterial branches has a great influence on flow streamlines and wall shear stress, particularly for side wall aneurysm.

[Monitoring and Modern Hemodynamic Concepts in Cardiac Anesthesia].

PubMed

Heringlake, Matthias; Schmidt, Christian; Brandt, Sebastian

2018-05-01

Patients undergoing cardiac surgery are growing older, present with more comorbidities, and are frequently scheduled for more complex and prolonged surgical procedures. Routine application of neurological as well as extended hemodynamic monitoring combined with goal-directed perioperative hemodynamic optimization, targeting optimization of systemic and cerebral oxygen balance, show promise to reduce postoperative complications and to improve mortality in this high risk population. Expert recommendations suggest to avoid synthetic colloids for fluid optimization. Additionally, pathophysiological reasoning and results from recent trials suggest to start inotropic and vasoactive therapy primarily with non-adrenergic drugs like levosimendan and vasopressin and to add classical catecholamines like dobutamine and noradrenalin only if necessary to accomplish hemodynamic goals. Georg Thieme Verlag KG Stuttgart · New York.

Calcitonin-gene related peptide and cerebral vasospasm.

PubMed

Schebesch, Karl-Michael; Herbst, Andreas; Bele, Sylvia; Schödel, Petra; Brawanski, Alexander; Stoerr, Eva-Maria; Lohmeier, Annette; Kagerbauer, Simone Maria; Martin, Jan; Proescholdt, Martin

2013-04-01

The pathophysiology of arterial vasospasm following subarachnoid hemorrhage (SAH) is poorly understood and the contribution of endogenous neuropeptides has not been sufficiently elucidated. Recently, we detected an excessive release of vasoconstrictive neuropeptide Y (NPY) in SAH patients and identified a significant correlation of NPY cerebrospinal fluid (CSF) levels with vasospasm-related ischemia. Here, we present the results of an experimental study on the possible role of the potent endogenous vasodilator calcitonin-gene related peptide (CGRP) in the acute stage of SAH. Twelve consecutive patients with SAH were included. Seven patients had severe arterial vasospasm, confirmed by transcranial doppler-sonography (TCD). Prospectively, CSF was collected from day 1 to day 10 after onset of the SAH. The levels of CGRP were determined in a competitive enzyme immunoassay and were correlated with the clinical course and hemodynamic changes. A cohort of 29 patients without CNS disease served as a control. CGRP was significantly higher in SAH patients compared with the control group (p<0.05). From day 1 to day 4, the CGRP levels in patients without vasospasm were significantly higher than the levels of CGRP in patients with vasospasm (p<0.05). These patients did not develop cerebral ischemia. The significantly increased levels of the CGRP during the first days after onset of the SAH in the non-vasospasm group indicate a potential protective role of CGRP. CGRP may alleviate arterial vasoconstriction and thus protect the brain from vasospasm and subsequent ischemia. Copyright © 2012 Elsevier Ltd. All rights reserved.

Urotensin II modulates hepatic fibrosis and portal hemodynamic alterations in rats.

PubMed

Kemp, William; Kompa, Andrew; Phrommintikul, Arintaya; Herath, Chandana; Zhiyuan, Jia; Angus, Peter; McLean, Catriona; Roberts, Stuart; Krum, Henry

2009-10-01

The influence of circulating urotensin II (UII) on liver disease and portal hypertension is unknown. We aimed to evaluate whether UII executes a pathogenetic role in the development of hepatic fibrosis and portal hypertension. UII was administered by continuous infusion over 4 wk in 20 healthy rats divided into three treatment groups, controls (saline, n = 7), low dose (UII, 1 nmol x kg(-1) x h(-1), n = 8), and high dose (UII, 3 nmol x kg(-1) x h(-1), n = 5). Hemodynamic parameters and morphometric quantification of fibrosis were assessed, and profibrotic cytokines and fibrosis markers were assayed in hepatic tissue. UII induced a significant dose-dependent increase in portal venous pressure (5.8 +/- 0.4, 6.4 +/- 0.3, and 7.6 +/- 0.7, respectively, P = 0.03). High-dose UII infusion was associated with an increase in hepatic transcript for transforming growth factor-beta (P < 0.05) and platelet-derived growth factor-beta (P = 0.06). Liver tissue hydroxyproline was elevated in the high-dose group (P < 0.05). No systemic hemodynamic alterations were noted. We concluded that UII infusion elevates portal pressure and induces hepatic fibrosis in normal rats. This response may be mediated via induction of fibrogenic cytokines. These findings have pathophysiological implications in human liver disease where increased plasma UII levels have been observed.

Antiadrenergic and hemodynamic effects of ranolazine in conscious dogs.

PubMed

Zhao, Gong; Walsh, Erin; Shryock, John C; Messina, Eric; Wu, Yuzhi; Zeng, Dewan; Xu, Xiaobin; Ochoa, Manuel; Baker, Stephen P; Hintze, Thomas H; Belardinelli, Luiz

2011-06-01

Effects of ranolazine alone and in the presence of phenylephrine (PE) or isoproterenol (ISO) on hemodynamics, coronary blood flow and heart rate (HR) in the absence and presence of hexamethonium (a ganglionic blocker) were studied in conscious dogs. Ranolazine (0.4, 1.2, 3.6, and 6 mg/kg, intravenous) alone caused transient (<1 minute) and reversible hemodynamic changes. PE (0.3-10 μg/kg) caused a dose-dependent increase in blood pressure and decrease in HR. ISO (0.01-0.3 μg/kg) caused a dose-dependent decrease in blood pressure and an increase in HR. Ranolazine at high (11-13 mM), but not at moderate (4-5 mM) concentrations partially attenuated changes in mean arterial blood pressure and HR caused by either PE or ISO in normal conscious dogs. However, in dogs treated with hexamethonium (20 mg/kg) to cause autonomic blockade, ranolazine (both 4-5 and 11-13 μM) significantly attenuated both the PE- and ISO-induced changes in mean arterial blood pressure. The results suggest that a potential antiadrenergic effect of ranolazine was masked by autonomic control mechanisms in conscious dogs but could be observed when these mechanisms were inhibited (eg, in the hexamethonium-treated dog). Ranolazine, at plasma concentrations <10 μM and in conscious dogs with intact autonomic regulation, had minimal antiadrenergic (α and β) effects.

Anti-Adrenergic and Hemodynamic Effects of Ranolazine in Conscious Dogs Zhao, Anti-Adrenergic Effect of Ranolazine

PubMed Central

Zhao, Gong; Walsh, Erin; Shryock, John; Messina, Eric; Wu, Yuzhi; Zeng, Dewan; Xu, Xiaobin; Ochoa, Manuel; Baker, Stephen; Hintze, Thomas; Belardinelli, Luiz

2012-01-01

Effects of ranolazine alone and in the presence of phenylephrine (PE) or isoproterenol (ISO) on hemodynamics, coronary blood flow (CBF) and heart rate (HR) in the absence and presence of hexamethonium (a ganglionic blocker) were studied in conscious dogs. Ranolazine (0.4, 1.2, 3.6 and 6 mg/kg, IV) alone caused transient (<1 min) and reversible hemodynamic changes. PE (0.3 to 10 μg/kg) caused a dose-dependent increase in BP and decrease in HR. ISO (0.01 to 0.3 μg/kg) caused a dose-dependent decrease in BP and increase in HR. Ranolazine at moderate (4-5 μM) and high (11-13 μM) concentrations did not affect the changes in MAP and HR caused by either PE or ISO, or partially attenuated these effects, respectively. However, in dogs treated with hexamethonium (20 mg/kg) to cause autonomic blockade, ranolazine (both 4-5 and 11-13 μM) significantly attenuated both the PE- and ISO-induced changes in MAP. The results suggest that a potential anti-adrenergic effect of ranolazine was masked by autonomic control mechanisms in conscious dogs, but could be observed when these mechanisms were inhibited (e.g., in the hexamethonium-treated dog). Ranolazine, at plasma concentrations below 10 μM and in conscious dogs with intact autonomic regulation, had minimal anti-adrenergic (α and β) effects. PMID:21633249

CFD-based Thrombotic Risk Assessment in Kawasaki Disease Patients with Coronary Artery Aneurysms

NASA Astrophysics Data System (ADS)

Sengupta, Dibyendu; Kung, Ethan; Kahn, Andrew; Burns, Jane; Marsden, Alison

2012-11-01

Coronary aneurysms occur in 25% of untreated Kawasaki Disease (KD) patients and put patients at increased risk for myocardial infarction and sudden death. Clinical guidelines recommend using aneurysm diameter >8 mm as the arbitrary criterion for treating with anti-coagulation therapy. This study uses patient-specific modeling to non-invasively determine hemodynamic parameters and quantify thrombotic risk. Anatomic models were constructed from CT angiographic image data from 5 KD aneurysm patients and one normal control. CFD simulations were performed to obtain hemodynamic data including WSS and particle residence times (PRT). Thrombosis was clinically observed in 4/9 aneurysmal coronaries. Thrombosed vessels required twice as many cardiac cycles (mean 8.2 vs. 4.2) for particles to exit, and had lower mean WSS (1.3 compared to 2.8 dynes/cm2) compared to vessels with non-thrombosed aneurysms of similar max diameter. 1 KD patient in the cohort with acute thrombosis had diameter < 8 mm. Regions of low WSS and high PRT predicted by simulations correlated with regions of subsequent thrombus formation. Thrombotic risk stratification for KD aneurysms may be improved by incorporating both hemodynamic and geometric quantities. Current clinical guidelines to assess patient risk based only on aneurysm diameter may be misleading. Further prospective study is warranted to evaluate the utility of patient-specific modeling in risk stratifying KD patients with coronary aneurysms. NIH R21.

Life Satisfaction and Hemodynamic Reactivity to Mental Stress.

PubMed

Schwerdtfeger, Andreas; Gaisbachgrabner, Kerstin; Traunmüller, Claudia

2017-06-01

Satisfaction with life has been considered a health-protective variable, which could impact cardiovascular morbidity and mortality. However, few studies have examined the physiological pathways involved in the potentially salutary effect of life satisfaction. It was hypothesized that life satisfaction should be associated with a cardiovascular response profile that signals challenge (i.e., higher cardiac output, lower peripheral resistance), rather than threat during a mental stress task. A sample of 75 healthy, medication-free men without clinical signs of psychological disorders who worked full-time and occupied highly demanding positions participated in this study. They performed two mental stress tasks (n-back) with varying degrees of difficulty. The tasks were embedded between a baseline and a recovery period. Cardiovascular and hemodynamic variables (heart rate, blood pressure, cardiac output, total peripheral resistance) were recorded by means of impedance cardiography. Individuals who were more satisfied with their life displayed higher cardiac output and lower peripheral resistance levels during the stress tasks, indicating a challenge rather than a threat profile. Findings were robust when controlled for physical activity, smoking, age, and depressive symptoms. Life satisfaction could be positively correlated with beneficial hemodynamic stress reactivity, indicating that individuals with higher levels of life satisfaction can more adaptively cope with stress. Increased cardiac output and decreased peripheral resistance during stress may constitute one route through which life satisfaction can benefit health.

Tomato lycopene attenuates myocardial infarction induced by isoproterenol: electrocardiographic, biochemical and anti-apoptotic study.

PubMed

Aman, Upaganlawar; Vaibhav, Patel; Balaraman, R

2012-05-01

To assess the protective effects of lycopene on electrocardiographic, hemodynamic, biochemical and apoptotic changes in isoproterenol induced myocardial infarction. Myocardial infarction was induced in rats by subcutaneous injection of isoproterenol (200 mg/kg) for two consecutive days at an interval of 24 h. Rats were treated with lycopene (10 mg/kg/day, p.o.) for a period of 30 days and isoproterenol (ISO) was injected on the 29th and 30th day. At the end of experiment i.e. on the 31st day electrocardiographic, hemodynamic, biochemical and apoptotic changes were monitored from control and experimental groups. ISO injected rats showed a significant alteration in electrocardiograph pattern and hemodynamic changes (i.e. systolic, diastolic and mean arterial pressure). It also showed significant increase in C-reactive protein, myeloperoxidase, nitrite levels and Caspase-3 protease activity. In addition, it also exhibited alteration in the levels of electrolytes (Na(+), K(+) and Ca(2+)), vitamin E, uric acid and serum protein. Gel electrophoresis of ISO injected rats showed increase in DNA fragmentation. Triphenyl tetrazolium chloride staining of the heart section shows increase area of infarction in ISO injected rats. Pre-co-treatment with lycopene significantly prevented the ISO induced alteration in ECG, haemodynamic, biochemical and apoptotic changes. The present result shows that treatment of lycopene in ISO injected rats significantly attenuates induced myocardial infarction.

Right ventricular contractile reserve in mitral stenosis: implications on hemodynamic burden and clinical outcome.

PubMed

Sade, Leyla Elif; Ozin, Bülent; Ulus, Taner; Açikel, Sadik; Pirat, Bahar; Bilgi, Muhammed; Uluçam, Melek; Müderrisoğlu, Haldun

2009-06-26

We investigated whether isovolumic acceleration (IVA) under inotropic stimulation as a means of right ventricular (RV) contractile reserve, is a surrogate for hemodynamic burden and has prognostic value in patients with mitral stenosis (MS). Thirty-one pure MS patients and 20 controls underwent cardiac catheterization, exercise test, and dobutamine stress echocardiography. RV fractional area change (FAC), +dP/dt/P(max), RV tissue Doppler indices (isovolumic contraction [IVC] and systolic [S] velocity, and IVA) were measured. Patients were followed-up for the occurrence of cardiac adverse events. Inotropic modulation unmasked statistically significant differences regarding magnitude of changes in IVA, IVC, S, and +dP/dt/P(max), but not RV FAC. Inability to increase IVA more than 6.5 m/s(2) was the only independent determinant of pulmonary capillary wedge pressure >or=18 mm Hg (P=.004). Although MS severity did not predict the RV contractile reserve and pulmonary artery pressure (PAP) behavior during inotropic stimulation, the RV contractile reserve was related to the degree of systolic PAP. IVA increases of <3.4 m/s(2) had 86% sensitivity and 75% specificity to predict unfavorable outcomes during long-term follow-up (20+/-8 months). RV contractile reserve provides complementary data to the hemodynamic significance of MS severity, may contribute to clinical decision making, and be of prognostic value in these patients.

Immunomodulation by splenectomy or by FTY720 protects the heart against ischemia reperfusion injury.

PubMed

Goltz, D; Huss, S; Ramadori, E; Büttner, R; Diehl, L; Meyer, R

2015-11-01

The pathogenesis of myocardial ischemia-reperfusion injury (MI/R) involves an inflammatory response in the myocardium undergoing reperfusion. Modulation of this response by splenectomy constitutes an option to protect the heart from MI/R. To mimic the effect of splenectomy in a pharmacological approach, the sphingosine-1-phosphate agonist FTY720 was applied at the onset of reperfusion. In a closed chest model of MI/R, infarct size was assessed by triphenyltetrazolium chloride staining after 1 h of ischemia and 24 h of reperfusion, and by Masson trichrome staining 21 days after reperfusion in splenectomised mice, mice post-conditioned with FTY720 IP (1 mg/kg), and controls. In addition, hemodynamic parameters were recorded after 24 h and 21 days by catheterization. Infarct size, and immune cell invasion of phagocytic monocytes investigated by FACS after 24 h of reperfusion were significantly reduced by both splenectomy, and FTY720 treatment. Evaluation after 21 days of reperfusion revealed that FTY720 treated animals had an improved hemodynamic outcome compared to placebo treated as well as splenectomised animals. FTY720 treatment reduced cell injury as effectively as splenectomy by lowering the number of phagocytic monocytes invading the myocardium and ameliorated hemodynamic outcome within the first 21 days. © 2015 Wiley Publishing Asia Pty Ltd.

Hemodynamic effects of spiral ePTFE prosthesis compared with standard arteriovenous graft in a carotid to jugular vein porcine model.

PubMed

Jahrome, Ommid K; Hoefer, Imo; Houston, Graeme J; Stonebridge, Peter A; Blankestijn, Peter J; Moll, Frans L; de Borst, Gert J

2011-01-01

The primary patency rate of arteriovenous (AV) grafts is limited by distal venous anastomosis stenosis or occlusion due to intimal hyperplasia associated with distal graft turbulence. The normal blood flow in native arteries is spiral laminar flow. Standard vascular grafts do not produce spiral laminar flow at the distal anastomosis. Vascular grafts which induce a spiral laminar flow distally result in lower turbulence, particularly near the vessel wall. This initial study compares the hemodynamic effects of a spiral flow-inducing graft and a standard graft in a new AV carotid to jugular vein crossover graft porcine model. Four spiral flow grafts and 4 control grafts were implanted from the carotid artery to the contralateral jugular vein in 4 pigs. Two animals were terminated after 48 hours and 2 at 14 days. Graft patency was assessed by selective catheter digital angiography, and the flow pattern was assessed by intraoperative flow probe and color Doppler ultrasound (CDU) measurements. The spiral grafts were also assessed at enhanced flow rates using an external roller pump to simulate increased flow rates that may occur during dialysis using a standard dialysis needle cannulation. The method increased the flow rate through the graft by 660 ml/min. The graft distal anastomotic appearances were evaluated by explant histopathology. All grafts were patent at explantation with no complications. All anastomoses were found to be wide open and showed no significant angiographic stenosis at the distal anastomosis in both spiral and control grafts. CDU examinations showed a spiral flow pattern in the spiral graft and double helix pattern in the control graft. No gross histopathological effects were seen in either spiral or control grafts. This porcine model is robust and allows hemodynamic flow assessment up to 14 days postimplantation. The spiral flow-inducing grafts produced and maintained spiral flow at baseline and enhanced flow rates during dialysis needle cannulation, whereas control grafts did not produce spiral flow through the distal anastomosis. There was no deleterious effect of the spiral flow-inducing graft on macroscopic and histological examination. The reducing effect of spiral flow on intima hyperplasia formation will be the subject of further study using the same AV graft model at a longer period of implantation.

Renal Hemodynamics and Ammoniagenesis

PubMed Central

Lemieux, Guy; Vinay, Patrick; Cartier, Pierre

1974-01-01

Renal production of ammonia by the left kidney was studied in 31 acidotic dogs (NH4Cl) after acute constriction of the renal artery. Renal ammoniagenesis fell in direct proportion with the reduction in glomerular filtration rate and renal plasma flow. The renal extraction of glutamine by the experimental kidney fell in direct proportion with the reduction in renal hemodynamics. Extracted glutamine remained greater than filtered glutamine indicating that both the luminal and antiluminal transport sites were operative. The relationship between renal extraction of glutamine and ammoniagenesis observed during control was maintained after renal artery constriction (1.7 μmol NH3 produced for each μmol of glutamine extracted). Systemic venous or renal intra-arterial infusion of glutamine during arterial constriction increased renal production of ammonia to or above control values. These observations indicate that the mechanisms responsible for glutamine extraction and ammonia production were operating normally despite reduced hemodynamics. When measured immediately after arterial clamping, the renal venous pNH3 was found to rise significantly decreasing progressively thereafter towards control values. The extracted fraction of total glutamine delivered to the kidney (31%) did not change after acute reduction of the glutamine load. Thus, the antiluminal extraction site was incapable of lowering renal venous plasma glutamine concentration below 0.33 μM/ml. In a second series of experiments, the properties of the antiluminal site of transport for glutamine were studied after complete occlusion of the left ureter in acidotic and nonacidotic animals. Under these circumstances, it was demonstrated that the antiluminal site is capable of extracting sufficient glutamine to maintain total ammonia production at 60% or more of control. In acidotic animals, changes in cellular pNH3 appeared to play a key role on the antiluminal extraction of glutamine since the significant rise in renal blood flow often observed after ureteral occlusion prevented the rise in pNH3 noted when blood flow remained constant. Thus, when renal blood flow rose glutamine extraction and ammonia production were maintained at control values. In these acidotic animals, glutamine infusion failed to influence ammonia production until luminal transport was restored by release of ureteral clamp and resumption of glomerular filtration. The latter observation establishes that reabsorbed glutamine is utilized at least in part for ammonia production. PMID:4812445

Dual implantation of a radio-telemeter and vascular access port allows repeated hemodynamic and pharmacological measures in conscious lean and obese rats.

PubMed

Bussey, C T; Leeuw, A E de; Cook, R F; Ashley, Z; Schofield, J; Lamberts, R R

2014-07-01

Expansion of physiological knowledge increasingly requires examination of processes in the normal, conscious state. The current study describes a novel approach combining surgical implantation of radio-telemeters with vascular access ports (VAPs) to allow repeated hemodynamic and pharmacological measures in conscious rats. Dual implantation was conducted on 16-week-old male lean and obese Zucker rats. Continued viability one month after surgery was observed in 67% of lean and 44% of obese animals, giving an overall 54% completion rate. Over the five-week measurement period, reliable and reproducible basal mean arterial pressure and heart rate measures were observed. VAP patency and receptor-independent vascular reactivity were confirmed by consistent hemodynamic responses to sodium nitroprusside (6.25 µg/kg). Acutely, minimal hemodynamic responses to repeated bolus administration of 0.2 mL saline indicated no significant effect of increased blood volume or administration stress, making repeated acute measures viable. Similarly, repeated administration of the β-adrenoceptor agonist dobutamine (30 µg/kg) at 10 min intervals resulted in reproducible hemodynamic changes in both lean and obese animals. Therefore, our study demonstrates that this new approach is viable for the acute and chronic assessment of hemodynamic and pharmacological responses in both lean and obese conscious rats. This technique reduces the demand for animal numbers and allows hemodynamic measures with minimal disruption to animals' welfare, while providing reliable and reproducible results over several weeks. In conclusion, dual implantation of a radio-telemeter and VAP introduces a valuable technique for undertaking comprehensive studies involving repeated pharmacological tests in conscious animals to address important physiological questions. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Effects of different levels of end-expiratory pressure on hemodynamic, respiratory mechanics and systemic stress response during laparoscopic cholecystectomy.

PubMed

Sen, Oznur; Erdogan Doventas, Yasemin

General anesthesia causes reduction of functional residual capacity. And this decrease can lead to atelectasis and intrapulmonary shunting in the lung. In this study we want to evaluate the effects of 5 and 10cmH 2 O PEEP levels on gas exchange, hemodynamic, respiratory mechanics and systemic stress response in laparoscopic cholecystectomy. American Society of Anesthesiologist I-II physical status 43 patients scheduled for laparoscopic cholecystectomy were randomly selected to receive external PEEP of 5cmH 2 O (PEEP 5 group) or 10cmH 2 O PEEP (PEEP 10 group) during pneumoperitoneum. Basal hemodynamic parameters were recorded, and arterial blood gases (ABG) and blood sampling were done for cortisol, insulin and glucose level estimations to assess the systemic stress response before induction of anesthesia. Thirty minutes after the pneumoperitoneum, the respiratory and hemodynamic parameters were recorded again and ABG and sampling for cortisol, insulin, and glucose levels were repeated. Lastly hemodynamic parameters were recorded; ABG analysis and sampling for stress response levels were taken after 60minutes from extubation. There were no statistical differences between the two groups about hemodynamic and respiratory parameters except mean airway pressure (P mean ). P mean , compliance and PaO 2 ; pH values were higher in 'PEEP 10 group'. Also, PaCO 2 values were lower in 'PEEP 10 group'. No differences were observed between insulin and lactic acid levels in the two groups. But postoperative cortisol level was significantly lower in 'PEEP 10 group'. Ventilation with 10cmH 2 O PEEP increases compliance and oxygenation, does not cause hemodynamic and respiratory complications and reduces the postoperative stress response. Copyright © 2016 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

[Effects of different levels of end-expiratory pressure on hemodynamic, respiratory mechanics and systemic stress response during laparoscopic cholecystectomy].

PubMed

Sen, Oznur; Erdogan Doventas, Yasemin

General anesthesia causes reduction of functional residual capacity. And this decrease can lead to atelectasis and intrapulmonary shunting in the lung. In this study we want to evaluate the effects of 5 and 10cmH 2 O PEEP levels on gas exchange, hemodynamic, respiratory mechanics and systemic stress response in laparoscopic cholecystectomy. American Society of Anesthesiologist I-II physical status 43 patients scheduled for laparoscopic cholecystectomy were randomly selected to receive external PEEP of 5cmH 2 O (PEEP 5 group) or 10cmH 2 O PEEP (PEEP 10 group) during pneumoperitoneum. Basal hemodynamic parameters were recorded, and arterial blood gases (ABG) and blood sampling were done for cortisol, insulin and glucose level estimations to assess the systemic stress response before induction of anesthesia. Thirty minutes after the pneumoperitoneum, the respiratory and hemodynamic parameters were recorded again and ABG and sampling for cortisol, insulin, and glucose levels were repeated. Lastly hemodynamic parameters were recorded; ABG analysis and sampling for stress response levels were taken after 60minutes from extubation. There were no statistical differences between the two groups about hemodynamic and respiratory parameters except mean airway pressure (P mean ). P mean , compliance and PaO 2 ; pH values were higher in 'PEEP 10 group'. Also, PaCO 2 values were lower in 'PEEP 10 group'. No differences were observed between insulin and lactic acid levels in the two groups. But postoperative cortisol level was significantly lower in 'PEEP 10 group'. Ventilation with 10cmH 2 O PEEP increases compliance and oxygenation, does not cause hemodynamic and respiratory complications and reduces the postoperative stress response. Copyright © 2016 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Central and peripheral hemodynamic responses to passive limb movement: the role of arousal

PubMed Central

Venturelli, Massimo; Amann, M.; McDaniel, J.; Trinity, J. D.; Fjeldstad, A. S.

2012-01-01

The exact role of arousal in central and peripheral hemodynamic responses to passive limb movement in humans is unclear but has been proposed as a potential contributor. Thus, we used a human model with no lower limb afferent feedback to determine the role of arousal on the hemodynamic response to passive leg movement. In nine people with a spinal cord injury, we compared central and peripheral hemodynamic and ventilatory responses to one-leg passive knee extension with and without visual feedback (M+VF and M-VF, respectively) as well as in a third trial with no movement or visual feedback but the perception of movement (F). Ventilation (V̇e), heart rate, stroke volume, cardiac output, mean arterial pressure, and leg blood flow (LBF) were evaluated during the three protocols. V̇e increased rapidly from baseline in M+VF (55 ± 11%), M-VF (63 ± 13%), and F (48 ± 12%) trials. Central hemodynamics (heart rate, stroke volume, cardiac output, and mean arterial pressure) were unchanged in all trials. LBF increased from baseline by 126 ± 18 ml/min in the M+VF protocol and 109 ± 23 ml/min in the M-VF protocol but was unchanged in the F protocol. Therefore, with the use of model that is devoid of afferent feedback from the legs, the results of this study reveal that, although arousal is invoked by passive movement or the thought of passive movement, as evidenced by the increase in V̇e, there is no central or peripheral hemodynamic impact of this increased neural activity. Additionally, this study revealed that a central hemodynamic response is not an obligatory component of movement-induced LBF. PMID:22003056

Time-resolved magnetic resonance angiography (MRA) at 3.0 Tesla for evaluation of hemodynamic characteristics of vascular malformations: description of distinct subgroups.

PubMed

Hammer, Simone; Uller, Wibke; Manger, Florentine; Fellner, Claudia; Zeman, Florian; Wohlgemuth, Walter A

2017-01-01

Quantitative evaluation of hemodynamic characteristics of arteriovenous and venous malformations using time-resolved magnetic resonance angiography (MRA) at 3.0 Tesla. Time-resolved MRA with interleaved stochastic trajectories (TWIST) at 3.0 Tesla was studied in 83 consecutive patients with venous malformations (VM) and arteriovenous malformations (AVM). Enhancement characteristics were calculated as percentage increase of signal intensity above baseline over time. Maximum percentage signal intensity increase (signal max ), time intervals between onset of arterial enhancement and lesion enhancement (t onset ), and time intervals between beginning of lesion enhancement and maximum percentage of lesion enhancement (t max ) were analyzed. All AVMs showed a high-flow hemodynamic pattern. Two significantly different (p < 0.001) types of venous malformations emerged: VMs with arteriovenous fistulas (AVF) (median signal max 737 %, IQR [interquartile range] = 511 - 1182 %; median t onset 5 s, IQR = 5 - 10 s; median t max 35 s, IQR = 26 - 40 s) and without AVFs (median signal max 284 %, IQR = 177-432 %; median t onset 23 s, IQR = 15 - 30 s; median t max 60 s, IQR = 55 - 75 s). Quantitative evaluation of time-resolved MRA at 3.0 Tesla provides hemodynamic characterization of vascular malformations. VMs can be subclassified into two hemodynamic subgroups due to presence or absence of AVFs. • Time-resolved MRA at 3.0 Tesla provides quantitative hemodynamic characterization of vascular malformations. • Malformations significantly differ in time courses of enhancement and signal intensity increase. • AVMs show a distinctive high-flow hemodynamic pattern. • Two significantly different types of VMs emerged: VMs with and without AVFs.

Effect of Magnesium Sulfate and Clonidine in Attenuating Hemodynamic Response to Pneumoperitoneum in Laparoscopic Cholecystectomy

PubMed Central

Kamble, Shruthi P.; Bevinaguddaiah, Yatish; Nagaraja, Dinesh Chillkunda; Pujar, Vinayak S.; Anandaswamy, Tejesh C.

2017-01-01

Background: Pneumoperitoneum in laparoscopic procedures is associated with hemodynamic response, due to the release of catecholamines and vasopressin. Magnesium and clonidine have been used to attenuate such hemodynamic responses by inhibiting release of these mediators. We conducted this randomized, double-blinded study to assess which of the two attenuates hemodynamic response better. Materials and Methods: Ninety American Society of Anesthesiologists health status Classes I and II patients posted for elective laparoscopic cholecystectomy were randomized into three groups of thirty patients each. Group C received injection clonidine 1 μg/kg diluted in 10 mL normal saline over 10 min, prior to pneumoperitoneum. Group M received injection magnesium sulfate 50 mg/kg diluted in 10 mL normal saline over 10 min, prior to pneumoperitoneum. Group NS received 10 mL normal saline intravenously over 10 min, prior to pneumoperitoneum. Hemodynamic parameters were recorded before induction (baseline values), at the end of magnesium sulfate/clonidine/saline administration and before pneumoperitoneum (P0), 5 min (P5), 10 min (P10), 20 min (P20), 30 min (P30), and 40 min (P40) after pneumoperitoneum. Results: Systolic blood pressure, diastolic blood pressure (DBP), mean arterial pressure (MAP), and heart rate (HR) were all significantly higher in the normal saline group compared to magnesium and clonidine. On comparing patients in Group M and Group C, DBP, MAP, and HR were significantly lower in the magnesium group. Mean extubation time and time to response to verbal commands were significantly longer in the magnesium group. Conclusions: Both magnesium and clonidine attenuated the hemodynamic response to pneumoperitoneum. However, magnesium 50 mg/kg, attenuated hemodynamic response better than clonidine 1 μg/kg. PMID:28298759

Role of donor hemodynamic trajectory in determining graft survival in liver transplantation from donation after circulatory death donors.

PubMed

Firl, Daniel J; Hashimoto, Koji; O'Rourke, Colin; Diago-Uso, Teresa; Fujiki, Masato; Aucejo, Federico N; Quintini, Cristiano; Kelly, Dympna M; Miller, Charles M; Fung, John J; Eghtesad, Bijan

2016-11-01

Donation after circulatory death (DCD) donors show heterogeneous hemodynamic trajectories following withdrawal of life support. Impact of hemodynamics in DCD liver transplant is unclear, and objective measures of graft viability would ease transplant surgeon decision making and inform safe expansion of the donor organ pool. This retrospective study tested whether hemodynamic trajectories were associated with transplant outcomes in DCD liver transplantation (n = 87). Using longitudinal clustering statistical techniques, we phenotyped DCD donors based on hemodynamic trajectory for both mean arterial pressure (MAP) and peripheral oxygen saturation (SpO 2 ) following withdrawal of life support. Donors were categorized into 3 clusters: those who gradually decline after withdrawal of life support (cluster 1), those who maintain stable hemodynamics followed by rapid decline (cluster 2), and those who decline rapidly (cluster 3). Clustering outputs were used to compare characteristics and transplant outcomes. Cox proportional hazards modeling revealed hepatocellular carcinoma (hazard ratio [HR] = 2.53; P = 0.047), cold ischemia time (HR = 1.50 per hour; P = 0.027), and MAP cluster 1 were associated with increased risk of graft loss (HR = 3.13; P = 0.021), but not SpO 2 cluster (P = 0.172) or donor warm ischemia time (DWIT; P = 0.154). Despite longer DWIT, MAP and SpO 2 clusters 2 showed similar graft survival to MAP and SpO 2 clusters 3, respectively. In conclusion, despite heterogeneity in hemodynamic trajectories, DCD donors can be categorized into 3 clinically meaningful subgroups that help predict graft prognosis. Further studies should confirm the utility of liver grafts from cluster 2. Liver Transplantation 22 1469-1481 2016 AASLD. © 2016 by the American Association for the Study of Liver Diseases.

Reactivity of hemodynamic responses and functional connectivity to different states of alpha synchrony: a concurrent EEG-fMRI study.

PubMed

Wu, Lei; Eichele, Tom; Calhoun, Vince D

2010-10-01

Concurrent EEG-fMRI studies have provided increasing details of the dynamics of intrinsic brain activity during the resting state. Here, we investigate a prominent effect in EEG during relaxed resting, i.e. the increase of the alpha power when the eyes are closed compared to when the eyes are open. This phenomenon is related to changes in thalamo-cortical and cortico-cortical synchronization. In order to investigate possible changes to EEG-fMRI coupling and fMRI functional connectivity during the two states we adopted a data-driven approach that fuses the multimodal data on the basis of parallel ICA decompositions of the fMRI data in the spatial domain and of the EEG data in the spectral domain. The power variation of a posterior alpha component was used as a reference function to deconvolve the hemodynamic responses from occipital, frontal, temporal, and subcortical fMRI components. Additionally, we computed the functional connectivity between these components. The results showed widespread alpha hemodynamic responses and high functional connectivity during eyes-closed (EC) rest, while eyes open (EO) resting abolished many of the hemodynamic responses and markedly decreased functional connectivity. These data suggest that generation of local hemodynamic responses is highly sensitive to state changes that do not involve changes of mental effort or awareness. They also indicate the localized power differences in posterior alpha between EO and EC in resting state data are accompanied by spatially widespread amplitude changes in hemodynamic responses and inter-regional functional connectivity, i.e. low frequency hemodynamic signals display an equivalent of alpha reactivity. Copyright 2010 Elsevier Inc. All rights reserved.

Sour taste increases swallowing and prolongs hemodynamic responses in the cortical swallowing network

PubMed Central

Kamarunas, Erin; Ludlow, Christy L.

2016-01-01

Sour stimuli have been shown to upregulate swallowing in patients and in healthy volunteers. However, such changes may be dependent on taste-induced increases in salivary flow. Other mechanisms include genetic taster status (Bartoshuk LM, Duffy VB, Green BG, Hoffman HJ, Ko CW, Lucchina LA, Weiffenbach JM. Physiol Behav 82: 109–114, 2004) and differences between sour and other tastes. We investigated the effects of taste on swallowing frequency and cortical activation in the swallowing network and whether taster status affected responses. Three-milliliter boluses of sour, sour with slow infusion, sweet, water, and water with infusion were compared on swallowing frequency and hemodynamic responses. The sour conditions increased swallowing frequency, whereas sweet and water did not. Changes in cortical oxygenated hemoglobin (hemodynamic responses) measured by functional near-infrared spectroscopy were averaged over 30 trials for each condition per participant in the right and left motor cortex, S1 and supplementary motor area for 30 s following bolus onset. Motion artifact in the hemodynamic response occurred 0–2 s after bolus onset, when the majority of swallows occurred. The peak hemodynamic response 2–7 s after bolus onset did not differ by taste, hemisphere, or cortical location. The mean hemodynamic response 17–22 s after bolus onset was highest in the motor regions of both hemispheres, and greater in the sour and infusion condition than in the water condition. Genetic taster status did not alter changes in swallowing frequency or hemodynamic response. As sour taste significantly increased swallowing and cortical activation equally with and without slow infusion, increases in the cortical swallowing were due to sour taste. PMID:27489363

Functional anatomy of autobiographical memory recall deficits in depression

PubMed Central

Young, K. D.; Erickson, K.; Nugent, A. C.; Fromm, S. J.; Mallinger, A. G.; Furey, M. L.; Drevets, W. C.

2012-01-01

Background Major depressive disorder (MDD) is associated with deficits in recalling specific autobiographical memories (AMs). Extensive research has examined the functional anatomical correlates of AM in healthy humans, but no studies have examined the neurophysiological underpinnings of AM deficits in MDD. The goal of the present study was to examine the differences in the hemodynamic response between patients with MDD and controls while they engage in AM recall. Method Participants (12 unmedicated MDD patients; 14 controls) underwent functional magnetic resonance imaging (fMRI) scanning while recalling AMs in response to positive, negative and neutral cue words. The hemodynamic response during memory recall versus performing subtraction problems was compared between MDD patients and controls. Additionally, a parametric linear analysis examined which regions correlated with increasing arousal ratings. Results Behavioral results showed that relative to controls, the patients with MDD had fewer specific (p=0.013), positive (p=0.030), highly arousing (p=0.036) and recent (p=0.020) AMs, and more categorical (p<0.001) AMs. The blood oxygen level-dependent (BOLD) response in the parahippocampus and hippocampus was higher for memory recall versus subtraction in controls and lower in those with MDD. Activity in the anterior insula was lower for specific AM recall versus subtraction, with the magnitude of the decrement greater in MDD patients. Activity in the anterior cingulate cortex was positively correlated with arousal ratings in controls but not in patients with MDD. Conclusions We replicated previous findings of fewer specific and more categorical AMs in patients with MDD versus controls. We found differential activity in medial temporal and prefrontal lobe structures involved in AM retrieval between MDD patients and controls as they engaged in AM recall. These neurophysiological deficits may underlie AM recall impairments seen in MDD. PMID:21798113

Neonatal Pneumothorax Pressures Surpass Higher Threshold in Lung Recruitment Maneuvers: An In Vivo Interventional Study.

PubMed

González-Pizarro, Patricio; García-Fernández, Javier; Canfrán, Susana; Gilsanz, Fernando

2016-02-01

Causing pneumothorax is one of the main concerns of lung recruitment maneuvers in pediatric patients, especially newborns. Therefore, these maneuvers are not performed routinely during anesthesia. Our objective was to determine the pressures that cause pneumothorax in healthy newborns by a prospective experimental study of 10 newborn piglets (<48 h old) with healthy lungs under general anesthesia. The primary outcome was peak inspiratory pressure (PIP) causing pneumothorax. Animals under anesthesia and bilateral chest tube catheterization were randomly allocated to 2 groups: one with PEEP and fixed inspiratory driving pressure of 15 cm H2O (PEEP group) and the second one with PEEP = 0 cm H2O and non-fixed inspiratory driving pressure (zero PEEP group). In both groups, the ventilation mode was pressure-controlled, and PIP was raised at 2-min intervals, with steps of 5 cm H2O until air leak was observed through the chest tubes. The PEEP group raised PIP through 5-cm H2O PEEP increments, and the zero PEEP group raised PIP through 5-cm H2O inspiratory driving pressure increments. Pneumothorax was observed with a PIP of 90.5 ± 15.7 cm H2O with no statistically significant differences between the PEEP group (92 ± 14.8 cm H2O) and the zero PEEP group (89 ± 18.2 cm H2O). The zero PEEP group had hypotension, with a PIP of 35 cm H2O; the PEEP group had hypotension, with a PIP of 60 cm H2O (P = .01). The zero PEEP group presented bradycardia, with PIP of 40 cm H2O; the PEEP group presented bradycardia, with PIP of 70 cm H2O (P = .002). Performing recruitment maneuvers in newborns without lung disease is a safe procedure in terms of pneumothorax. Pneumothorax does not seem to occur in the clinically relevant PIPs of <50 cm H2O. Hemodynamic impairment may occur with high driving pressures. More studies are needed to determine the exact hemodynamic impact of these procedures and pneumothorax PIP in poorly compliant lungs. Copyright © 2016 by Daedalus Enterprises.

Increased anterior cingulate cortex response precedes behavioural adaptation in anorexia nervosa

PubMed Central

Geisler, Daniel; Ritschel, Franziska; King, Joseph A.; Bernardoni, Fabio; Seidel, Maria; Boehm, Ilka; Runge, Franziska; Goschke, Thomas; Roessner, Veit; Smolka, Michael N.; Ehrlich, Stefan

2017-01-01

Patients with anorexia nervosa (AN) are characterised by increased self-control, cognitive rigidity and impairments in set-shifting, but the underlying neural mechanisms are poorly understood. Here we used functional magnetic resonance imaging (fMRI) to elucidate the neural correlates of behavioural adaptation to changes in reward contingencies in young acutely ill AN patients. Thirty-six adolescent/young adult, non-chronic female AN patients and 36 age-matched healthy females completed a well-established probabilistic reversal learning task during fMRI. We analysed hemodynamic responses in empirically-defined regions of interest during positive feedback and negative feedback not followed/followed by behavioural adaptation and conducted functional connectivity analyses. Although overall task performance was comparable between groups, AN showed increased shifting after receiving negative feedback (lose-shift behaviour) and altered dorsal anterior cingulate cortex (dACC) responses as a function of feedback. Specifically, patients had increased dACC responses (which correlated with perfectionism) and task-related coupling with amygdala preceding behavioural adaption. Given the generally preserved task performance in young AN, elevated dACC responses specifically during behavioural adaption is suggestive of increased monitoring for the need to adjust performance strategies. Higher dACC-amygdala coupling and increased adaptation after negative feedback underlines this interpretation and could be related to intolerance of uncertainty which has been suggested for AN. PMID:28198813

Influence of exercise induced hyperlactatemia on retinal blood flow during normo- and hyperglycemia.

PubMed

Garhöfer, Gerhard; Kopf, Andreas; Polska, Elzbieta; Malec, Magdalena; Dorner, Guido T; Wolzt, Michael; Schmetterer, Leopold

2004-05-01

Short term hyperglycemia has previously been shown to induce a blood flow increase in the retina. The mechanism behind this effect is poorly understood. We set out to investigate whether exercise-induced hyperlactatemia may alter the response of retinal blood flow to hyperglycemia. We performed a randomized, controlled two-way cross over study comprising 12 healthy subjects, performed a 6-minutes period of dynamic exercise during an euglcaemic or hyperglycaemic insulin clamp. Retinal blood flow was assessed by combined vessel size measurement with the Zeiss retinal vessel analyzer and measurement of red blood cell velocities using bi-directional laser Doppler velocimetry. Retinal and systemic hemodynamic parameters were measured before, immediately after and 10 and 20 minutes after isometric exercise. On the euglycemic study day retinal blood flow increased after dynamic exercise. The maximum increase in retinal blood flow was observed 10 minutes after the end of exercise when lactate plasma concentration peaked. Hyperglycemia increased retinal blood flow under basal conditions, but had no incremental effect during exercise induced hyperlactatemia. Our results indicate that both lactate and glucose induce an increase in retinal blood flow in healthy humans. This may indicate a common pathway between glucose and lactate induced blood flow changes in the human retina.

Noninvasive Optical Monitoring of Spinal Cord Hemodynamics and Oxygenation after Acute Spinal Cord Injury

DTIC Science & Technology

2017-09-01

oxygen delivery and oxygen consumption . The oxygen portion of the Oxylite probe emits short pulses of blue LED light resulting in a fluorescent...Award Number: W81XWH-16-1-0602 TITLE: Noninvasive Optical Monitoring of Spinal Cord Hemodynamics and Oxygenation after Acute Spinal Cord Injury...COVERED 1 Sep 2016 - 31 Aug 2017 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Noninvasive Optical Monitoring of Spinal Cord Hemodynamics and Oxygenation

Preload assessment and optimization in critically ill patients.

PubMed

Voga, Gorazd

2010-01-01

Preload assessment and optimization is the basic hemodynamic intervention in critically ill. Beside clinical assessment, non-invasive or invasive assessment by measurement of various pressure or volume hemodynamic variables, are helpful for estimation of preload and fluid responsiveness. The use of dynamic variables is useful in particular subgroup of critically ill patients. In patients with inadequate preload, fluid responsiveness and inadequate flow, treatment with crystalloids or colloids is mandatory. When rapid hemodynamic response is necessary colloids are preferred.

Role of pulmonary hemodynamics in determining 6-minute walk test result in atrial septal defect: an observational study.

PubMed

Supomo, Supomo; Darmawan, Handy; Arjana, Adika Zhulhi

2018-05-22

The presence of altered pulmonary hemodynamics in adult patients with atrial septal defect (ASD) is common. However, there are no observational studies which evaluate the impact of altered pulmonary hemodynamics on the 6-min walk test (6MWT) result. This study aimed to investigate the role of pulmonary hemodynamics in determining 6MWT result of patients with ASD. Forty-six consecutive adult patients with ASD were included in this study. Right heart catheterization was performed to obtain the pulmonary hemodynamics profile. Meanwhile, 6MWT was presented as high or low with cut-off point 350 m. Receiver operating characteristic (ROC) was used for analytical methods. Abnormal functional capacity was indicated by ROC result of mPAP cut-off value of > 24 mmHg (p = 0.0243; AUC = 0.681). The value of PVR > 3.42 woods unit (WU) showed high specificity in determining abnormal functional capacity (p = 0.0069; AUC = 0.713). Flow ratio with cut-off point ≤4.89 had the highest sensitivity (100%) (p = 0.8300; AUC = 0.520). Pulmonary hemodynamics can serve as an indicator of 6MWT result in adult ASD patients with values of mPAP> 24 mmHg and PVR > 3.42 WU.

Hemodynamic coherence and the rationale for monitoring the microcirculation.

PubMed

Ince, Can

2015-01-01

This article presents a personal viewpoint of the shortcoming of conventional hemodynamic resuscitation procedures in achieving organ perfusion and tissue oxygenation following conditions of shock and cardiovascular compromise, and why it is important to monitor the microcirculation in such conditions. The article emphasizes that if resuscitation procedures are based on the correction of systemic variables, there must be coherence between the macrocirculation and microcirculation if systemic hemodynamic-driven resuscitation procedures are to be effective in correcting organ perfusion and oxygenation. However, in conditions of inflammation and infection, which often accompany states of shock, vascular regulation and compensatory mechanisms needed to sustain hemodynamic coherence are lost, and the regional circulation and microcirculation remain in shock. We identify four types of microcirculatory alterations underlying the loss of hemodynamic coherence: type 1, heterogeneous microcirculatory flow; type 2, reduced capillary density induced by hemodilution and anemia; type 3, microcirculatory flow reduction caused by vasoconstriction or tamponade; and type 4, tissue edema. These microcirculatory alterations can be observed at the bedside using direct visualization of the sublingual microcirculation with hand-held vital microscopes. Each of these alterations results in oxygen delivery limitation to the tissue cells despite the presence of normalized systemic hemodynamic variables. Based on these concepts, we propose how to optimize the volume of fluid to maximize the oxygen-carrying capacity of the microcirculation to transport oxygen to the tissues.

Hemodynamic changes in a rat parietal cortex after endothelin-1-induced middle cerebral artery occlusion monitored by optical coherence tomography

NASA Astrophysics Data System (ADS)

Liu, Jian; Ma, Yushu; Dou, Shidan; Wang, Yi; La, Dongsheng; Liu, Jianghong; Ma, Zhenhe

2016-07-01

A blockage of the middle cerebral artery (MCA) on the cortical branch will seriously affect the blood supply of the cerebral cortex. Real-time monitoring of MCA hemodynamic parameters is critical for therapy and rehabilitation. Optical coherence tomography (OCT) is a powerful imaging modality that can produce not only structural images but also functional information on the tissue. We use OCT to detect hemodynamic changes after MCA branch occlusion. We injected a selected dose of endothelin-1 (ET-1) at a depth of 1 mm near the MCA and let the blood vessels follow a process first of occlusion and then of slow reperfusion as realistically as possible to simulate local cerebral ischemia. During this period, we used optical microangiography and Doppler OCT to obtain multiple hemodynamic MCA parameters. The change trend of these parameters from before to after ET-1 injection clearly reflects the dynamic regularity of the MCA. These results show the mechanism of the cerebral ischemia-reperfusion process after a transient middle cerebral artery occlusion and confirm that OCT can be used to monitor hemodynamic parameters.

Monitoring Detrusor Oxygenation and Hemodynamics Noninvasively during Dysfunctional Voiding

PubMed Central

Macnab, Andrew J.; Stothers, Lynn S.; Shadgan, Babak

2012-01-01

The current literature indicates that lower urinary tract symptoms (LUTSs) related to benign prostatic hyperplasia (BPH) have a heterogeneous pathophysiology. Pressure flow studies (UDSs) remain the gold standard evaluation methodology for such patients. However, as the function of the detrusor muscle depends on its vasculature and perfusion, the underlying causes of LUTS likely include abnormalities of detrusor oxygenation and hemodynamics, and available treatment options include agents thought to act on the detrusor smooth muscle and/or vasculature. Hence, near infrared spectroscopy (NIRS), an established optical methodology for monitoring changes in tissue oxygenation and hemodynamics, has relevance as a means of expanding knowledge related to the pathophysiology of BPH and potential treatment options. This methodological report describes how to conduct simultaneous NIRS monitoring of detrusor oxygenation and hemodynamics during UDS, outlines the clinical implications and practical applications of NIRS, explains the principles of physiologic interpretation of NIRS voiding data, and proposes an exploratory hypothesis that the pathophysiological causes underlying LUTS include detrusor dysfunction due to an abnormal hemodynamic response or the onset of oxygen debt during voiding. PMID:23019422

[Hemodynamic changes in hypoglycemic shock].

PubMed

Gutiérrez, C; Piza, R; Chousleb, A; Hidalgo, M A; Ortigosa, J L

1977-01-01

Severe hypoglycemia may be present in seriously ill patients; if it is not corrected opportunely a series of neuroendocrinal mechanisms take place aimed at correcting metabolic alterations. These mechanisms can produce hemodynamic alterations as well. Nine mongrel dogs were studied with continuous registration of: blood pressure, central venous pressure, cardiac frequency, respiratory frequency, electrocardiogram and first derivative (Dp/Dt). Six dogs received crystalline (fast acting) insuline intravenously (group 1). After hemodynamic changes were registered hypoglycemia was corrected with 50 per cent glucose solution. Complementary insuline doses were administered to three dogs (group 2); in this group hypoglycemia was not corrected. In group 1 during hypoglycemia there was an increase in blood pressure, central venous pressure, cardiac frequency, respiratory frequency and Dp/Dt, and changes in QT and T wave on the EKG; these changes were partially reversible after hypoglycemia was corrected. The above mentioned alterations persisted in group 2, breathing became irregular irregular and respiratory arrest supervened. It can be inferred that the hemodynamic response to hypoglycemia is predominantly adrenergic. The role of catecolamines, glucocorticoides, glucagon, insuline, cyclic AMP in metabolic and hemodynamic alterations consecutive to hypoglycemia are discussed.

Outcomes of truncal vascular injuries in children

PubMed Central

Allison, Nathan D.; Anderson, Christopher M.; Shah, Shinil K.; Lally, Kevin P.; Hayes-Jordan, Andrea; Tsao, Kuo-Jen; Andrassy, Richard J.; Cox, Charles S.

2011-01-01

Background Pediatric truncal vascular injuries occur infrequently and have a reported mortality rate of 30% to 50%. This report examines the demographics, mechanisms of injury, associated trauma, and outcome of patients presenting for the past 10 years at a single institution with truncal vascular injuries. Methods A retrospective review (1997-2006) of a pediatric trauma registry at a single institution was undertaken. Results Seventy-five truncal vascular injuries occurred in 57 patients (age, 12 ± 3 years); the injury mechanisms were penetrating in 37%. Concomitant injuries occurred with 76%, 62%, and 43% of abdominal, thoracic, and neck vascular injuries, respectively. Nonvascular complications occurred more frequently in patients with abdominal vascular injuries who were hemodynamically unstable on presentation. All patients with thoracic vascular injuries presenting with hemodynamic instability died. In patients with neck vascular injuries, 1 of 2 patients who were hemodynamically unstable died, compared to 1 of 12 patients who died in those who presented hemodynamically stable. Overall survival was 75%. Conclusions Survival and complications of pediatric truncal vascular injury are related to hemodynamic status at the time of presentation. Associated injuries are higher with trauma involving the abdomen. PMID:19853755

Assessment of hemodynamics of intracranial aneurysms using Doppler optical coherence tomography in patient specific phantoms: preliminary results (Conference Presentation)

NASA Astrophysics Data System (ADS)

Ramjist, Joel M.; Jivraj, Jamil; Barrows, Dexter; Vuong, Barry; Wong, Ronnie; Yang, Victor X. D.

2017-02-01

Intracranial aneurysms affect a large number of individuals every year. Changes to hemodynamics are thought to be a crucial factor in the initial formation and enlargement of intracranial aneurysms. Previously, surgical clipping - an open an invasive procedure, was the standard of care. More recently, minimally invasive, catheter based therapies, specifically stenting and coiling, has been employed for treatment as it is less invasive and poses fewer overall risks. However, these treatments can further alter hemodynamic patterns of patients, affecting efficacy and prognosis. Doppler optical coherence tomography (DOCT) has shown to be useful for the evaluation of changes to hemodynamic patterns in various vascular pathologies, and intravascular DOCT may provide useful insight in the evaluation and changes to hemodynamic patterns before and during the treatment of aneurysms. In this study, we present preliminary results of DOCT imaging used in three patient-specific aneurysm phantoms located within the Circle of Willis both pre and post-treatment. These results are compared with computational fluid dynamics (CFD) simulations and high-speed camera imaging for further interpretation and validation of results.

Physical Factors Effecting Cerebral Aneurysm Pathophysiology

PubMed Central

Sadasivan, Chander; Fiorella, David J.; Woo, Henry H.; Lieber, Baruch B.

2013-01-01

Many factors that are either blood-, wall-, or hemodynamics-borne have been associated with the initiation, growth, and rupture of intracranial aneurysms. The distribution of cerebral aneurysms around the bifurcations of the circle of Willis has provided the impetus for numerous studies trying to link hemodynamic factors (flow impingement, pressure, and/or wall shear stress) to aneurysm pathophysiology. The focus of this review is to provide a broad overview of such hemodynamic associations as well as the subsumed aspects of vascular anatomy and wall structure. Hemodynamic factors seem to be correlated to the distribution of aneurysms on the intracranial arterial tree and complex, slow flow patterns seem to be associated with aneurysm growth and rupture. However, both the prevalence of aneurysms in the general population and the incidence of ruptures in the aneurysm population are extremely low. This suggests that hemodynamic factors and purely mechanical explanations by themselves may serve as necessary, but never as necessary and sufficient conditions of this disease’s causation. The ultimate cause is not yet known, but it is likely an additive or multiplicative effect of a handful of biochemical and biomechanical factors. PMID:23549899

Hemodynamics of physiological blood flow in the aorta with nonlinear anisotropic heart valve

NASA Astrophysics Data System (ADS)

Sotiropoulos, Fotis; Gilmanov, Anvar; Stolarski, Henryk

2016-11-01

The hemodynamic blood flow in cardiovascular system is one of the most important factor, which causing several vascular diseases. We developed a new Curvilinear Immersed Boundary - Finite Element - Fluid Structure Interaction (CURVIB-FE-FSI) method to analyze hemodynamic of pulsatile blood flow in a real aorta with nonlinear anisotropic aortic valve at physiological conditions. Hyperelastic material model, which is more realistic for describing heart valve have been incorporated in the CURVIB-FE-FSI code to simulate interaction of aortic heart valve with pulsatile blood flow. Comparative studies of hemodynamics for linear and nonlinear models of heart valve show drastic differences in blood flow patterns and hence differences of stresses causing impact at leaflets and aortic wall. This work is supported by the Lillehei Heart Institute at the University of Minnesota.

Sildenafil increases cerebrovascular reactivity: a transcranial Doppler study.

PubMed

Diomedi, M; Sallustio, F; Rizzato, B; Ferrante, F; Leone, G; Spera, E; Scarfini, M; Bernardi, G

2005-09-27

The authors performed a double-blind, placebo-controlled study in 28 patients to evaluate the effects of sildenafil on cerebral hemodynamics. A significant improvement of cerebrovascular reactivity, without any modification of other variables, was recorded 1 hour after the administration of 50 mg sildenafil. Further investigations are needed to evaluate whether cerebrovascular reactivity improvement could contribute to triggering sildenafil-induced migraine.

An Extracorporeal Artificial Placenta Supports Extremely Premature Lambs for One Week

PubMed Central

Bryner, Benjamin; Gray, Brian; Perkins, Elena; Davis, Ryan; Hoffman, Hayley; Barks, John; Owens, Gabe; Bocks, Martin; Rojas-Peña, Alvaro; Hirschl, Ronald; Bartlett, Robert; Mychaliska, George

2015-01-01

Purpose The treatment of extreme prematurity remains an unsolved problem. We developed an artificial placenta (AP) based on extracorporeal life support (ECLS) that simulates the intrauterine environment and provides gas exchange without mechanical ventilation (MV), and compared it to the current standard of neonatal care. Methods Extremely premature lambs (110-120d; term=145d) were used. AP lambs (n=9) were cannulated (jugular drainage, umbilical vein reinfusion) for ECLS .Control lambs (n=7) were intubated, ventilated, given surfactant, and transitioned to high-frequency oscillatory ventilation. All lambs received parenteral nutrition, antibiotics, and steroids. Hemodynamics, blood gases, hemoglobin, and circuit flows were measured. Results Four premature lambs survived for 1 week on the AP; one survived 6 days. Adequate oxygenation and ventilation were provided by the AP. The MV lambs survived 2-8 hours. Each of these lambs experienced a transient improvement with surfactant, but developed progressive hypercapnea and hypoxia despite high airway pressures and HFOV. Conclusions Extremely premature lambs were supported for 1 week with the AP with hemodynamic stability and adequate gas exchange; mechanically ventilated lambs succumbed within 8 hours. Further studies will assess control of fetal circulation and organ maturation on the AP. PMID:25598091

Peripheral vascular responses to heat stress after hindlimb suspension

NASA Technical Reports Server (NTRS)

Looft-Wilson, Robin C.; Gisolfi, Carl V.

2002-01-01

PURPOSE: The purpose of this study was to determine whether hindlimb suspension (which simulates the effects of microgravity) results in impaired hemodynamic responses to heat stress or alterations in mesenteric small artery sympathetic nerve innervation. METHODS: Over 28 d, 16 male Sprague-Dawley rats were hindlimb-suspended, and 13 control rats were housed in the same type of cage. After the treatment, mean arterial pressure (MAP), colonic temperature (Tcol), and superior mesenteric and iliac artery resistances (using Doppler flowmetry) were measured during heat stress [exposure to 42 degrees C until the endpoint of 80 mm Hg blood pressure was reached (75 +/- 9 min); endpoint Tcore = 43.6 +/- 0.2] while rats were anesthetized (sodium pentobarbital, 50 mg x kg(-1) BW). RESULTS: Hindlimb-suspended and control rats exhibited similar increases in Tcol, MAP, and superior mesenteric artery resistance, and similar decreases in iliac resistance during heat stress (endpoint was a fall in MAP below 80 mm Hg). Tyrosine hydroxylase immunostaining indicated similar sympathetic nerve innervation in small mesenteric arteries from both groups. CONCLUSION: Hindlimb suspension does not alter the hemodynamic or thermoregulatory responses to heat stress in the anesthetized rat or mesenteric sympathetic nerve innervation, suggesting that this sympathetic pathway is intact.

[Hemodynamic activities in children with autism while imitating emotional facial expressions: a near-infrared spectroscopy study].

PubMed

Mori, Kenji; Mori, Tatsuo; Goji, Aya; Ito, Hiromichi; Toda, Yoshihiro; Fujii, Emiko; Miyazaki, Masahito; Harada, Masafumi; Kagami, Shoji

2014-07-01

To examine the hemodynamic activities in the frontal lobe, children with autistic disorder and matched controls underwent near-infrared spectroscopy (NIRS) while imitating emotional facial expressions. The subjects consisted of 10 boys with autistic disorder without mental retardation (9 - 14 years) and 10 normally developing boys (9 - 14 years). The concentrations of oxyhemoglobin (oxy-Hb) were measured with frontal probes using a 34-channel NIRS machine while the subjects imitated emotional facial expressions. The increments in the concentration of oxy-Hb in the pars opercularis of the inferior frontal gyrus in autistic subjects were significantly lower than those in the controls. However, the concentrations of oxy-Hb in this area were significantly elevated in autistic subjects after they were trained to imitate emotional facial expressions. The increments in the concentration of oxy-Hb in this area in autistic subjects were positively correlated with the scores on a test of labeling emotional facial expressions. The pars opercularis of the inferior frontal gyrus is an important component of the mirror neuron system. The present results suggest that mirror neurons could be activated by repeated imitation in children with autistic disorder.

Hemodynamic responses to external counterbalancing of auto-positive end-expiratory pressure in mechanically ventilated patients with chronic obstructive pulmonary disease.

PubMed

Baigorri, F; de Monte, A; Blanch, L; Fernández, R; Vallés, J; Mestre, J; Saura, P; Artigas, A

1994-11-01

To study the effect of positive end-expiratory pressure (PEEP) on right ventricular hemodynamics and ejection fraction in patients with chronic obstructive pulmonary disease and positive alveolar pressure throughout expiration by dynamic hyperinflation (auto-PEEP). Open, prospective, controlled trial. General intensive care unit of a community hospital. Ten patients sedated and paralyzed with an acute exacerbation of chronic obstructive pulmonary disease undergoing mechanical ventilation. Insertion of a pulmonary artery catheter modified with a rapid response thermistor and a radial arterial catheter. PEEP was then increased from 0 (PEEP 0) to auto-PEEP level (PEEP = auto-PEEP) and 5 cm H2O above that (PEEP = auto-PEEP +5). At each level of PEEP, airway pressures, flow and volume, hemodynamic variables (including right ventricular ejection fraction by thermodilution technique), and blood gas analyses were recorded. The mean auto-PEEP was 6.6 +/- 2.8 cm H2O and the total PEEP reached was 12.2 +/- 2.4 cm H2O. The degree of lung inflation induced by PEEP averaged 145 +/- 87 mL with PEEP = auto-PEEP and 495 +/- 133 mL with PEEP = auto-PEEP + 5. The PEEP = auto-PEEP caused a right ventricular end-diastolic pressure increase, but there was no other significant hemodynamic change. With PEEP = auto-PEEP + 5, there was a significant increase in intravascular pressures; this amount of PEEP reduced cardiac output (from 4.40 +/- 1.38 L/min at PEEP 0 to 4.13 +/- 1.48 L/min; p < .05). The cardiac output reduction induced by PEEP = auto-PEEP + 5 was > 10% in only five cases and this group of patients had significantly lower right ventricular volumes than the group with less cardiac output variation (right ventricular end-diastolic volume: 64 +/- 9 vs. 96 +/- 26 mL/m2; right ventricular end-systolic volume: 38 +/- 6 vs. 65 +/- 21 mL/m2; p < .05) without significant difference in the other variables that were measured. Neither right ventricular ejection fraction nor right ventricle volumes changed as PEEP increased, but there were marked interpatient differences and also pronounced changes in volume between stages in individual patients. In the study conditions, PEEP application up to values approaching auto-PEEP did not result in the impairment of right ventricular hemodynamics, while higher levels reduced cardiac output in selected patients.

[Diuretics in heart failure and Karl Popper's turkey].

PubMed

Cice, Gennaro

2015-12-01

Heart failure and renal failure often coexist in the same patient. This condition is commonly referred to as cardiorenal syndrome. When this occurs, patient survival worsens significantly with increasing degree of renal dysfunction. Management of this complex patient poses treatment challenges because of unstable hemodynamics (the problem is to reduce congestion without affecting organ perfusion) and very high mid-term in-hospital mortality. Congestion is a typical feature of this syndrome, and use of diuretics is mandatory. Loop diuretics should be administered first. However, poor attention to pharmacodynamic and pharmacokinetic properties of loop diuretics may contribute to the development of diuretic resistance leading to iatrogenic hyponatremia. Accordingly, emphasis is given to the importance of sequential nephron blockade to reduce the number of non-responder patients to diuretics and to recognize a possible role for acquaretics.