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41.
Yang-Chun Chen Ruo-Zhu Dai Ke-Lian Zhang Yong-Da Dong Hui-Lin Zhuo Qing-Mu Wang 《核技术(英文版)》2017,28(1)
This work was to determine threshold values for accurate measurements of left ventricular end-diastolic volume(EDV),end-systolic volume(ESV),and ejection fraction(EF) from electrocardiography-gated myocardial perfusion imaging(MPI) in Chinese,and these data were compared with those of echocardiography.A total of 110 patients with definite or suspected coronary artery disease were referred for both gated MPI and echocardiography within 1 week.The EDV,ESV,and EF automatically measured by MyoMetrix and echocardiography were analyzed using Bland-Altman plot correlation and paired t test.The results showed that these parameters quantified by MyoMetrix software were correlated,moderately to highly,with those on echocardiography(ρ,r ≥0.75,P0.01).However,the EF was not significantly correlated,with post-exercise MPI ESV of 15 mL or resting MPI ESV of 20 mL.At or above this ESV value,EF was underestimated by MyoMetrix(t≥ 4.60,P0.01).In a word,a small ESV was underestimated by MyoMetrix,which could lead to EF overestimation.On the contrary,a normal or large ESV was overestimated by MyoMetrix,which led to EF underestimation. 相似文献
42.
Smith Timothy W.; Cribbet Matthew R.; Nealey-Moore Jill B.; Uchino Bert N.; Williams Paula G.; MacKenzie Justin; Thayer Julian F. 《Canadian Metallurgical Quarterly》2011,100(1):103
Maintenance of relationship quality requires self-regulation of emotion and social behavior, and women often display greater effort in this regard than do men. Furthermore, such efforts can deplete the limited capacity for self-regulation. In recent models of self-regulation, resting level of respiratory sinus arrhythmia, quantified as high-frequency heart rate variability (HF-HRV), is an indicator of self-regulatory capacity, whereas transient increases in HF-HRV reflect self-regulatory effort. To test these hypotheses in marriage, 114 young couples completed measures of marital quality and a positive, neutral, or negative initial marital task, preceded and followed by resting baseline assessments of HF-HRV. Couples then discussed a current marital disagreement. Resting HF-HRV was correlated with marital quality, suggesting that capacity for self-regulation is associated with adaptive functioning in close relationships. For women but not men, the negative initial task produced a decrease in resting HF-HRV. This effect was mediated by the husbands' negative affect response to the task and their ratings of wives as controlling and directive. When the subsequent disagreement discussion followed the negative initial task, women displayed increased HF-HRV during the discussion but a decrease when it followed the neutral or positive task. The valence of the initial task had no effect on men's HF-HRV during disagreement. Negative marital interactions can reduce women's resting HF-HRV, with potentially adverse health consequences. Women's reduced health benefit from marriage might reflect the depleting effects on self-regulatory capacity of their greater efforts to manage relationship quality. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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The key objective of this work is the design of an unconditionally stable, robust, efficient, modular, and easily expandable finite element‐based simulation tool for cardiac electrophysiology. In contrast to existing formulations, we propose a global–local split of the system of equations in which the global variable is the fast action potential that is introduced as a nodal degree of freedom, whereas the local variable is the slow recovery variable introduced as an internal variable on the integration point level. Cell‐specific excitation characteristics are thus strictly local and only affect the constitutive level. We illustrate the modular character of the model in terms of the FitzHugh–Nagumo model for oscillatory pacemaker cells and the Aliev–Panfilov model for non‐oscillatory ventricular muscle cells. We apply an implicit Euler backward finite difference scheme for the temporal discretization and a finite element scheme for the spatial discretization. The resulting non‐linear system of equations is solved with an incremental iterative Newton–Raphson solution procedure. Since this framework only introduces one single scalar‐valued variable on the node level, it is extremely efficient, remarkably stable, and highly robust. The features of the general framework will be demonstrated by selected benchmark problems for cardiac physiology and a two‐dimensional patient‐specific cardiac excitation problem. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
44.
目的: 观察阿托伐他汀对自发性高血压大鼠(SHR)心室重构的影响。方法: 24只SHR 随机分为4组,每组6只。SHR对照组、阿托伐他汀50mg组(50mg·kg-1·d-1)、阿托伐他汀10mg组(10 mg·kg-1·d-1)和缬沙坦组(20mg·kg-1·d-1);6只Wistar-Kyoto 大鼠(WKY)作为正常对照组。灌胃给药共6 周,分别于给药前和给药后每2 周测量大鼠尾动脉收缩压(SBP)。酶法测定血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)及低密度脂蛋白胆固醇(LDL-C)含量,放免法测定血浆和心肌血管紧张素Ⅱ(Ang Ⅱ)水平,并检测心肌羟脯氨酸、胶原蛋白含量和全心重量(HW)、左室重量(LVM)及左室重量指数(LVMI)。透射电镜观察心肌超微结构改变。结果: 用药前SHR 各组SBP均显著高于WKY 正常对照组(P<0.01),给药后第4、6 周,阿托伐他汀50 mg 组SBP明显下降(P<0.01),阿托伐他汀10 mg 组不明显;缬沙坦组自给药后第2 周,SBP明显下降(P<0.01)。阿托伐他汀50 mg 组TC、TG 及LDL-C水平较SHR 对照组明显降低(P<0.05或P<0.01),阿托伐他汀10 mg 组仅LDL-C 水平明显下降(P<0.05)。SHR对照组血浆Ang Ⅱ浓度与WKY 正常对照组比较无显著性差异,但心肌Ang Ⅱ浓度明显增高(P<0.05);给药6 周后,阿托伐他汀各剂量组和缬沙坦组血浆Ang Ⅱ浓度显著高于SHR 对照组(P<0.01),而心肌Ang Ⅱ 浓度在阿托伐他汀50 mg 组和缬沙坦组明显降低(P<0.05)。SHR 对照组心肌羟脯氨酸和胶原蛋白含量较WKY 正常对照组明显升高(P<0.01);6 周后,阿托伐他汀50 mg 组较SHR 对照组降低(P<0.05)。SHR组HW、LVM和LVMI与WKY正常对照组相比增高(P<0.01),而阿托伐他汀50 mg 组却低于SHR 对照组(P<0.05)。透射电镜观察心肌超微结构显示,阿托伐他汀50mg组和缬沙坦组与SHR对照组比较,心肌细胞核膜较完整,肌原纤维清晰,排列较整齐,横纹清楚,间质胶原纤维无明显增生。结论: 阿托伐他汀能明显改善SHR 的心室重构,降低血压和心肌Ang Ⅱ浓度可能为其机制之一。 相似文献
45.
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47.
Ravaja Niklas; Kallinen Kari; Saari Timo; Keltikangas-Jarvinen Liisa 《Canadian Metallurgical Quarterly》2004,10(2):120
The authors examined the effects of suboptimally presented facial expressions on emotional and attentional responses and memory among 39 young adults viewing video (business news) messages from a small screen. Facial electromyography (EMG) and respiratory sinus arrhythmia were used as physiological measures of emotion and attention, respectively. Several congruency priming effects were found. In particular, happy facial primes prompted increased (a) pleasure ratings, (b) orbicularis oculi EMG activity, (c) perceived trustworthiness, and (d) recognition memory for video messages with a positive emotional tone. Emotional and other responses to video messages presented on a small screen can be modified with suboptimal affective primes, but even small differences in the emotional tone of the messages should be allowed for. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
48.
49.
Boyang Su Liang Zhong Xi-Kun Wang Jun-Mei Zhang Ru San Tan John Carson Allen Soon Keat Tan Sangho Kim Hwa Liang Leo 《Computer methods and programs in biomedicine》2014
Intraventricular flow is important in understanding left ventricular function; however, relevant numerical simulations are limited, especially when heart valve function is taken into account. In this study, intraventricular flow in a patient-specific left ventricle has been modelled in two-dimension (2D) with both mitral and aortic valves integrated. The arbitrary Lagrangian–Eulerian (ALE) approach was employed to handle the large mesh deformation induced by the beating ventricular wall and moving leaflets. Ventricular wall deformation was predefined based on MRI data, while leaflet dynamics were predicted numerically by fluid–structure interaction (FSI). Comparisons of simulation results with in vitro and in vivo measurements reported in the literature demonstrated that numerical method in combination with MRI was able to predict qualitatively the patient-specific intraventricular flow. To the best of our knowledge, we are the first to simulate patient-specific ventricular flow taking into account both mitral and aortic valves. 相似文献
50.
Hypertrophic Cardiomyopathy (HCM) is a common inherited disorder characterized by unexplained left ventricular hypertrophy with or without left ventricular outflow tract (LVOT) obstruction. Single-nuclei RNA-sequencing (snRNA-seq) of both obstructive and nonobstructive HCM patient samples has revealed alterations in communication between various cell types, but no direct and integrated comparison between the two HCM phenotypes has been reported. We performed a bioinformatic analysis of HCM snRNA-seq datasets from obstructive and nonobstructive patient samples to identify differentially expressed genes and distinctive patterns of intercellular communication. Differential gene expression analysis revealed 37 differentially expressed genes, predominantly in cardiomyocytes but also in other cell types, relevant to aging, muscle contraction, cell motility, and the extracellular matrix. Intercellular communication was generally reduced in HCM, affecting the extracellular matrix, growth factor binding, integrin binding, PDGF binding, and SMAD binding, but with increases in adenylate cyclase binding, calcium channel inhibitor activity, and serine-threonine kinase activity in nonobstructive HCM. Increases in neuron to leukocyte and dendritic cell communication, in fibroblast to leukocyte and dendritic cell communication, and in endothelial cell communication to other cell types, largely through changes in the expression of integrin-β1 and its cognate ligands, were also noted. These findings indicate both common and distinct physiological mechanisms affecting the pathogenesis of obstructive and nonobstructive HCM and provide opportunities for the personalized management of different HCM phenotypes. 相似文献