T波峰-末间期对急性心肌梗死并发室性心律失常的预测价值

目的:探讨T波峰-末间期(Tp-Te间期)和Tp-Te间期离散度(Tp-Ted)对急性心肌梗死并发室性心律失常的预测价值。方法:选择我院2013年5月至2014年5月收治的140例确诊急性ST段抬高型心肌梗死(STEMI)患者,按照心律失常类型分为室性心动过速组,室性早搏组以及无室性心律失常组。分析并比较各组患者心电图Tp-Te间期及Tp-Ted的变化情况。结果:急性期FPG、Tp-Te、Tp-Ted高于恢复期,差异有统计学意义(P0.05);急性期与恢复期之间TG、CHOL、LDL-C、K+、Na+水平差异无统计学意义(P0.05)。无室性心律失常组与室性心动过速组及室性早搏组比较,Tp-Te和Tp-Ted更低,差异有统计学意义(P0.05);室性早搏组和室性心动过速组比较,Tp-Te和Tp-Ted更低,差异有统计学意义(P0.05)。结论:Tp-Te间期和Tp-Ted可用于区分急性心肌梗死患者室性心律失常类型。     

Evaluation of Left Ventricular Endocardial Cardiac Resynchronization Therapy in a Non-responder with Ventricular Arrhythmias

Approximately one third of patients treated with cardiac resynchronization therapy do not derive any detectable benefit. In these patients, acute invasive hemodynamic evaluation can be used for therapy optimization. This report describes the use of systematic invasive hemodynamic measurements for clinical decision making in a patient who experienced severe ventricular arrhythmias and clinical deterioration following a biventricular upgrade.     

Percutenous catheter ablation of the accessory pathway in a patient with wolff-Parkinson-white syndrome associated with familial atrial fibrillation

Percutenous catheter ablation of the accessory pathway in Wolff-Parkinson-White syndrome is a highly successful mode of therapy. Sudden cardiac arrest survivors associated with WPW syndrome should undergo radiofrequency catheter ablation. WPW syndrome associated with familial atrial fibrillation is a very rare condition. Herein, we describe a case who presented with sudden cardiac arrest secondary to WPW syndrome and familial atrial fibrillation and treated via radiofrequency catheter ablation.     

Circadian Rhythms of Early Afterdepolarizations and Ventricular Arrhythmias in a Cardiomyocyte Model

Sudden cardiac arrest is a malfunction of the heart’s electrical system, typically caused by ventricular arrhythmias, that can lead to sudden cardiac death (SCD) within minutes. Epidemiological studies have shown that SCD and ventricular arrhythmias are more likely to occur in the morning than in the evening, and laboratory studies indicate that these daily rhythms in adverse cardiovascular events are at least partially under the control of the endogenous circadian timekeeping system. However, the biophysical mechanisms linking molecular circadian clocks to cardiac arrhythmogenesis are not fully understood. Recent experiments have shown that L-type calcium channels exhibit circadian rhythms in both expression and function in guinea pig ventricular cardiomyocytes. We developed an electrophysiological model of these cells to simulate the effect of circadian variation in L-type calcium conductance. In our simulations, we found that there is a circadian pattern in the occurrence of early afterdepolarizations (EADs), which are abnormal depolarizations during the repolarization phase of a cardiac action potential that can trigger fatal ventricular arrhythmias. Specifically, the model produces EADs in the morning, but not at other times of day. We show that the model exhibits a codimension-2 Takens-Bogdanov bifurcation that serves as an organizing center for different types of EAD dynamics. We also simulated a two-dimensional spatial version of this model across a circadian cycle. We found that there is a circadian pattern in the breakup of spiral waves, which represents ventricular fibrillation in cardiac tissue. Specifically, the model produces spiral wave breakup in the morning, but not in the evening. Our computational study is the first, to our knowledge, to propose a link between circadian rhythms and EAD formation and suggests that the efficacy of drugs targeting EAD-mediated arrhythmias may depend on the time of day that they are administered.     

Ghrelin对心肌梗死大鼠恶性心律失常和早期左室重构的影响(英文)

目的:本文主要研究ghrelin对心肌梗死大鼠恶性心律失常和早期左室重构的影响。方法:心肌梗死大鼠模型每天两次注射ghrelin(100μg/kg)或生理盐水。通过超声心动图评估大鼠的心脏重量并且观察大鼠的血流动力学。使用酶免疫分析法测定血清胰岛素生长因子I(IGF-1)、血浆肾上腺素、去甲肾上腺素和多巴胺的浓度。注射药物前后分析大鼠的神经功能。结果:与对照组相比,ghrelin治疗的心肌梗死模型大鼠生存率显著增加(P0.05),心脏功能增强,但心肌梗死面积差异不大(P0.05)。结论:Ghrelin能够提高心肌梗死模型大鼠的生存率、缓解心肌梗死大鼠心率失常、改善心肌梗死大鼠左心室重构。     

扩张型心肌病患者恶性室性心律失常与心率变异性关系分析

目的:了解扩张型心肌病患者恶性心律失常(MVA)与心率变异性(heart rate variability,HRV)的关系,探讨扩心病患者体内自主神经变化的临床意义。方法:选择扩心病患者48例作为研究对象,同时按照年龄配对,取48例正常者作为对照组,对其行24小时动态心电图检查,依据其是否出现恶性心律失常分为恶性室性心律失常(MVA+)组及单纯扩张型心肌病(MVA-)组,分析组间HRV的差异。结果:与对照组比较,单纯扩张型心肌病(MVA-)组HRV时域指标(SDNN、SDANN、RMSSD)均有降低(P<0.05)L与(MVA-)组相比,恶性室性心律失常(MVA+)组HRV相关指标进一步降低(P<0.05)。结论:自主神经功能异常是扩张型心肌病患者恶性心律失常的重要危险因子,可能可以用HRV预测其发生恶性心律失常危险性。     

恶性肿瘤患者营养状况与生活质量的关系

目的：探讨恶性肿瘤患者营养状况与生活质量间的相关关系。方法：应用改良SGAN评估法和SF-36健康调查量袁对65例恶性肿瘤患者进行营养状况和生活质量评估,并对其做相关性分析。结果：恶性肿瘤患者的生活质量各维度均明显降低,并随营养状况的下降而降低。结论：恶性肿瘤患者的生活质量明显下降,营养状况与生活质量密切相关,提示提高患者营养状况可以改善生活质量。     

恶性肿瘤患者营养状况与生活质量的关系

目的:探讨恶性肿瘤患者营养状况与生活质量间的相关关系。方法:应用改良SGAN评估法和SF-36健康调查量表对65例恶性肿瘤患者进行营养状况和生活质量评估,并对其做相关性分析。结果:恶性肿瘤患者的生活质量各维度均明显降低,并随营养状况的下降而降低。结论:恶性肿瘤患者的生活质量明显下降,营养状况与生活质量密切相关,提示提高患者营养状况可以改善生活质量。     

Left Ventricular Function during Acute High-Altitude Exposure in a Large Group of Healthy Young Chinese Men

Objective

The purpose of this study was to observe left ventricular function during acute high-altitude exposure in a large group of healthy young males.

Methods

A prospective trial was conducted in Szechwan and Tibet from June to August, 2012. By Doppler echocardiography, left ventricular function was examined in 139 healthy young Chinese men at sea level; within 24 hours after arrival in Lhasa, Tibet, at 3700 m; and on day 7 following an ascent to Yangbajing at 4400 m after 7 days of acclimatization at 3700 m. The resting oxygen saturation (SaO2), heart rate (HR) and blood pressure (BP) were also measured at the above mentioned three time points.

Results

Within 24 hours of arrival at 3700 m, the HR, ejection fraction (EF), fractional shortening (FS), stroke volume (SV), cardiac output (CO), and left ventricular (LV) Tei index were significantly increased, but the LV end-systolic dimension (ESD), end-systolic volume (ESV), SaO2, E/A ratio, and ejection time (ET) were significantly decreased compared to the baseline levels in all subjects. On day 7 at 4400 m, the SV and CO were significantly decreased; the EF and FS Tei were not decreased compared with the values at 3700 m; the HR was further elevated; and the SaO2, ESV, ESD, and ET were further reduced. Additionally, the E/A ratio was significantly increased on day 7 but was still lower than it was at low altitude.

Conclusion

Upon acute high-altitude exposure, left ventricular systolic function was elevated with increased stroke volume, but diastolic function was decreased in healthy young males. With higher altitude exposure and prolonged acclimatization, the left ventricular systolic function was preserved with reduced stroke volume and improved diastolic function.     

Suppression of frequent ventricular ectopy in a patient with hypertrophic heart disease with ranolazine: a case report

Background

Pro-arrhythmic concerns with most anti-arrhythmic agents in patients with significant left ventricular hypertrophy (LVH) limits options when anti-arrhythmic therapy is indicated. Ranolazine, an anti-anginal agent which inhibits late Na+ currents, indirectly causes a decrease in diastolic cardiomyocyte Ca++ levels producing an energy sparing effect. Ranolazine also inhibits triggered activity in animal studies and has anti-arrhythmic properties in patients with ischemic heart disease. Here we report the dramatic anti-arrhythmic effects of ranolazine in a patient with frequent ventricular and supraventricular ectopy in the setting of hypertrophic heart disease without significant coronary artery disease.

Methods

A 72 year old hypertensive patient with palpitations and significant exercise intolerance due to dyspnea was evaluated with echocardiography, thallium stress testing and cardiac catheterization. Holter monitor data prior to, and after institution of ranolazine 1000 mg twice daily was compared. Patient tolerance and sense of well being after ranolazine was assessed.

Results

Significant LVH was noted and obstructive coronary artery disease was ruled out by cardiac catheterization. Within two hours of the initial dose of ranolazine a marked decrease in ventricular ectopy was observed. Ventricular ectopy on Holter monitor decreased approximately 12 fold (23.8% of beats to1.9%) while supraventricular ectopy decreased approximately 7 fold (5.3% of beats to 0.8%). The decrease in ectopy was associated with an improved sense of well being.

Conclusion

Ranolazine had rapid onset, potent anti-arrhythmic properties in the absence of obstructive coronary artery disease in a patient with LVH and may be an ideal agent in patients where few anti-arrhythmic options exist.     

Dyssynchronous Ventricular Activation in Asymptomatic Wolff-Parkinson-White Syndrome: A Risk Factor for Development of Dilated Cardiomyopathy

A subset of children and adults with Wolff-Parkinson-White (WPW) syndrome develop dilated cardiomyopathy (DCM). Although DCM may occur in symptomatic WPW patients with sustained tachyarrhythmias, emerging evidence suggests that significant left ventricular dysfunction may arise in WPW in the absence of incessant tachyarrhythmias. An invariable electrophysiological feature in this non-tachyarrhythmia type of DCM is the presence of a right-sided septal or paraseptal accessory pathway. It is thought that premature ventricular activation over these accessory pathways induces septal wall motion abnormalities and ventricular dyssynchrony. LV dyssynchrony induces cellular and structural ventricular remodelling, which may have detrimental effects on cardiac performance. This review summarizes recent evidence for development of DCM in asymptomatic patients with WPW, discusses its pathogenesis, clinical presentation, management and treatment. The prognosis of accessory pathway-induced DCM is excellent. LV dysfunction reverses following catheter ablation of the accessory pathway, suggesting an association between DCM and ventricular preexcitation. Accessory pathway-induced DCM should be suspected in all patients presenting with heart failure and overt ventricular preexcitation, in whom no cause for their DCM can be found.     

Brugada ECG Pattern Unmasked by IV Flecainide in an Individual with Idiopathic Fascicular Ventricular Tachycardia

A 45-year old man presents with stable monomorphic ventricular tachycardia. He had previously been diagnosed with idiopathic fascicular ventricular tachycardia. Intravenous flecainide results in termination of his tachycardia but unmasks a latent type 1 Brugada ECG pattern not seen on his resting ECG. We discuss his subsequent management and the need to consider an alternative diagnosis in individuals with a Brugada type ECG pattern who present with stable monomorphic ventricular tachycardia.     

真社会性生活方式在隧蜂亚科中的分布格局

对隧蜂的各种生活方式的涵义作了解释。基于文献资料,总结了营真社会性生活方式的种类在隧蜂亚科中的分布格局,旨在为研究昆虫真社会性的起源和进化奠定理论基础。     

Serum Uric Acid Is Associated with Left Ventricular Hypertrophy Independent of Serum Parathyroid Hormone in Male Cardiac Patients

Background

Several studies have shown that serum uric acid (UA) is associated with left ventricular (LV) hypertrophy. Serum levels of parathyroid hormone (PTH), which has bbe shown to be correlated with UA, is also known to be associated with cardiac hypertrophy; however, whether the association between UA and cardiac hypertrophy is independent of PTH remains unknown.

Purpose

We investigated whether the relationship between serum uric acid (UA) and LV hypertrophy is independent of intact PTH and other calcium-phosphate metabolism-related factors in cardiac patients.

Methods and Results

In a retrospective study, the association between UA and left ventricular mass index was assessed among 116 male cardiac patients (mean age 65±12 years) who were not taking UA lowering drugs. The median UA value was 5.9 mg/dL. Neither age nor body mass index differed significantly among the UA quartile groups. Patients with higher UA levels were more likely to be taking loop diuretics. UA showed a significant correlation with intact PTH (R = 0.34, P<0.001) but not with other calcium-phosphate metabolism-related factors. Linear regression analysis showed that log-transformed UA showed a significant association with left ventricular mass index, and this relationship was found to be significant exclusively in patients who were not taking loop and/or thiazide diuretics. Multivariate logistic regression analysis showed that log-transformed UA was independently associated with LV hypertrophy with an odds ratio of 2.79 (95% confidence interval 1.48–5.28, P = 0.002 per one standard deviation increase).

Conclusions

Among cardiac patients, serum UA was associated with LV hypertrophy, and this relationship was, at least in part, independent of intact PTH levels, which showed a significant correlation with UA in the same population.     

Successful Right Ventricular Tachycardia Ablation in a Patient with Left Ventricular Non-compaction Cardiomyopathy

We report a case of a 67-year old male with a recent diagnosis of left ventricular noncompaction (LVNC), initially presenting with symptomatic ventricular ectopy and runs of non-sustained ventricular tachycardia (VT). This ventricular arrhythmia originated in a structurally normal right ventricle (RV) and was successfully localized and ablated with the aid of the three-dimensional mapping and remote magnetic navigation.     

Cell Adhesion as a Basis of Pattern in Embryonic Development

The development of the modern methodologies of cell biologyin the fifties and sixties and of molecular biology in the seventiesand eighties has led to a reductionist view of embryonic developmentthat centers on the cell and the gene as the functional unitsof development. The functional units in most inductive and morphogeneticprocesses in the embryo are not single cells, however, but ratherare collectives of interacting cells that give rise to the tissuesand organs. Can these methodological developments reconcilea molecular analysis with the fact that form arises epigeneticallyfrom the increasing number of embryonic cells during development?To answer this question one must link genetic regulation tomechanochemical processes that coordinate cell division, cellmovement and cell death. Recent studies of cell adhesion suggestthat one such link is provided by cell adhesion molecules (CAMs)that mediate cell-cell binding. These studies suggest that CAMsare involved in defining cell collectives and their bordersas they interact during inductive events in morphogenesis. AlthoughCAMs cannot be considered the "cause" of induction, they playkey roles among the complex causal chains of inductive interactionsinvolving hormones and growth-factors, extracellular matrixcomponents and cellular receptors. We provide here a brief summaryof modern developments in the field centered about the functionof CAMs in morphogenesis and using recent experimental resultsin the developing feather as a paradigmatic example.     

Ablation of Premature Ventricular Complexes Triggering Ventricular Fibrillation in a Patient with Long QT Syndrome

We describe the case of a patient with long QT syndrome and recurrent ventricular fibrillation, triggered by premature ventricular complexes (PVCs) with a left bundle branch block pattern and inferior axis of the QRS. Activation mapping demonstrated the origin of the PVCs to be in the right ventricular outflow tract. Ventricular fibrillation (VF) was successfully treated by catheter ablation of the triggering PVCs and there has been no recurrence of VF during a follow-up period of 14 months.     

Mucosal immune responses to infections in infants with acute life threatening events classified as 'near-miss' sudden infant death syndrome

This study examined the hypothesis that dysregulation of mucosal immune responses to respiratory infections is a critical event, which could be causal in respiratory arrest of some previously healthy infants. To examine this hypothesis, a prospective study was undertaken of infants presenting to the emergency department of a major teaching hospital with acute life threatening events (ALTE) of unknown cause and classified as "near-miss" SIDS. Salivary immunoglobulin concentrations were measured on admission and again after 14 days. The salivary immunoglobulins were compared with three control groups: infants with a mild upper respiratory tract infection (URTI); bronchiolitis; and healthy age-matched infants. The salivary IgA and IgM concentrations in the ALTE infants at presentation to hospital indicated a significant mucosal immune response had already occurred, with nearly 60% of the IgA concentrations significantly above the population-based reference ranges. The hyper-immune response was most evident in the ALTE infants with pathology evidence of an infection; 87% of these infants had salivary IgA concentrations on average 10 times higher that the age-related median concentration. The most prevalent pathogen identified in the ALTE infants was respiratory syncytial virus (RSV) (64%). RSV was also identified in all subjects with bronchiolitis. Risk factors for SIDS were assessed in each group. The data indicated that the ALTE infants diagnosed as 'near-miss' SIDS were a relatively homogeneous group, and most likely these ALTE infants and SIDS represent associated clinical outcomes. The study identified exposure to cigarette smoke and elevated salivary IgA concentrations as predictors of an ALTE. The study findings support the hypothesis of mucosal immune dysregulation in response to a respiratory infection in some infants with an ALTE. They provide a plausible explanation for certain SIDS risk factors. The underlying patho-physiological mechanism of proinflammatory responses to infections during a critical developmental period might be a critical factor in infants who have life-threatening apnoea or succumb to SIDS. The study raises the possibility of using salivary IgA to test infants who present with mild respiratory infections to identify a substantial number of infants at risk of developing an ALTE or SIDS, thus enabling intervention management to prevent such outcomes.     

Individual differences in boldness positively correlate with heart rate in orb-weaving spiders of genus Larinioides

Recent years have seen a dramatic increase in the number of studies devoted to consistent individual differences in behavior, termed ＂behavioral syndromes＂ or animal ＂personality＂. In particular, ecologists and evolutionary biologists alike seek to explore the functional consequences of individuals＇ personalities and explanations for their general maintenance. Understand ing the mechanistic underpinnings to personality is arguably key to a deeper understanding of their functional consequences and maintenance. In particular, consistent individual differences in metabolic rate have been proposed as a general explanation for the maintenance of consistent individual differences in boldness, aggressiveness, and activity level. In this paper we explore whether consistent individual differences in boldness are associated with heat rate, a proxy for metabolic rate, in two species of orbweaving spider： Larinioides cornutus and L. patagiatus. We first documented consistent individual differences in boldness in L. cornutus but not L. patagiatus, as estimated by individuals＇ latency to resume movement following an aversive stimulus. We also measured individuals＇ heart rate twice in a separate situation. We then tested for an association between individuals＇ boldness and their heart rate during these two events. We found that increased boldness was associated with increased heart. Thus, indi viduals that resumed movement quickly following an aversive stimulus also exhibited faster heart rates. Our studies provide fur ther evidence that consistent individual differences in key physiological attributes, like metabolic rate, might be a general mecha nism underlying consistent individual differences in behavior .