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Sample records for premature ventricular beats

  1. Acupuncture Treatment for 98 Cases of Ventricular Premature Beat

    Institute of Scientific and Technical Information of China (English)

    Han Baojie; Wang Feng; Wang Xinzhong

    2008-01-01

    @@ Ventricular premature beat is a commonly encountered arrhythmia,which can occur in patients with and without cardiac diseases.In TCM.ventricular premature beat fall into the category of palpitation and obstruction of qi in the chest.The authors treated it with acupuncture and obtained satisfactory thera-peutic effects.A summary follows.

  2. Early repolarization as a predictor of premature ventricular beats.

    Science.gov (United States)

    Matoshvili, Z T; Petriashvili, Sh G; Archadze, A T; Azaladze, I G

    2015-02-01

    Early repolarization pattern (ERP) is a common ECG variant, characterized by J point elevation manifested either as terminal QRS slurring (the transition from the QRS segment to the ST segment) or notching (a positive deflection inscribed on terminal QRS complex) associated with concave upward ST-segment elevation and prominent T waves in at least two contiguous leads. Aim of this observational study was to compare number of premature ventricular beats in the different groups of patients with early repolarization. The result of this observational study shows that there are: 1,74 fold higher number of premature ventricular beats in 41-74 year subgroup VS 19-40 year subgroup; 1,31 fold higher number of premature ventricular beats in male subgroup VS female subgroup (But this difference is not statistically significant, because t=1,49, p=0,141); 2,85 fold higher number of premature ventricular beats in CAD+ERP subgroup VS ERP without CAD subgroup; 1,74 fold higher number of premature ventricular beats in HF+ERP subgroup VS ERP without HF subgroup; 1,81 fold higher number of premature ventricular beats in CAD+ERP subgroup VS CAD without ERP subgroup; 1,58 fold higher number of premature ventricular beats in HF+ERP subgroup VS HF without ERP subgroup; So, CAD+ERP is very arrhythmogenic condition, after this is HF+ERP, Then Age. This study shows that ERP independently increase number of PVB in different groups (CAD, HF). This is principally new and very important result. Also the number of patients is enough to make this conclusion.

  3. J point elevation as a predictor of premature ventricular beats.

    Science.gov (United States)

    Matoshvili, Z; Petriashvili, Sh; Archvadze, A; Azaladze, I

    2014-01-01

    Early repolarization pattern (ERP) is a common ECG variant, characterized by J point elevation manifested either as terminal QRS slurring (the transition from the QRS segment to the ST segment) or notching (a positive deflection inscribed on terminal QRS complex) associated with concave upward ST-segment elevation and prominent T waves in at least two contiguous leads. 36 patients were included in this observation. There are 36 patients (19-68 years old) with early repolarization ECG patterns. All this 36 patients were divided into two groups according to their level of J point elevation. First group consisted of 12 patients with J point elevation ≥0,15 mV; second group - of 24 patients with J point elevation premature ventricular beat during 24 h. Before and during this monitoring patients don't take any antyarrhythmic drugs. In the first group (J point elevation ≥0,15 mV) sum of premature ventricular beats were 27432, in the second group (J point elevation premature ventricular beats were 31 896. The results of this observational study shows that there is 1,72 fold higher number of premature ventricular beats in first group. So, J point elevation equal or more then 0,15 mV, is more arrhythmogenic and induces premature ventricular beats. This is principally new and very important result.

  4. Outpatient evaluation and management of patients with ventricular premature beats or non-sustained ventricular tachycardia

    DEFF Research Database (Denmark)

    Svendsen, Jesper Hastrup; Goette, Andreas; Dobreanu, Dan

    2012-01-01

    In this survey, European physicians who deal with arrhythmia patients gave their opinions about diagnostic work up when they see patients with ventricular premature beats (VPBs) or non-sustained ventricular tachycardia (NSVT). In general, similar work-up regimens were used for these two arrhythmias...

  5. Heart rate turbulence after ventricular premature beats in healthy Doberman pinschers and those with dilated cardiomyopathy.

    Science.gov (United States)

    Harris, J D; Little, C J L; Dennis, J M; Patteson, M W

    2017-09-25

    To describe the measurement of heart rate turbulence (HRT) after ventricular premature beats and compare HRT in healthy Doberman pinschers and those with dilated cardiomyopathy (DCM), with and without congestive heart failure (CHF). Sixty-five client-owned Dobermans: 20 healthy (NORMAL), 31 with preclinical DCM and 14 with DCM and CHF (DCM + CHF). A retrospective study of data retrieved from clinical records and ambulatory ECG (Holter) archives, including data collected previously for a large-scale prospective study of Dobermans with preclinical DCM. Holter data were reanalysed quantitatively, including conventional time-domain heart rate variability and the HRT parameters turbulence onset and turbulence slope. Heart rate turbulence could be measured in 58/65 dogs. Six Holter recordings had inadequate ventricular premature contractions (VPCs) and one exhibited VPCs too similar to sinus morphology. Heart rate turbulence parameter, turbulence onset, was significantly reduced in DCM dogs, whereas conventional heart rate variability measures were not. Heart rate variability and HRT markers were reduced in DCM + CHF dogs as expected. Heart rate turbulence can be measured from the majority of good quality standard canine 24-hour Holter recordings with >5 VPCs. Turbulence onset is significantly reduced in Dobermans with preclinical DCM which indicates vagal withdrawal early in the course of disease. Heart rate turbulence is a powerful prognostic indicator in human cardiac disease which can be measured from standard 24-hour ambulatory ECG (Holter) recordings using appropriate computer software. Further studies are warranted to assess whether HRT may be of prognostic value in dogs with preclinical DCM and in other canine cardiac disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. The Effects of Female Sex Hormones on Ventricular Premature Beats and Repolarization Parameters in Physiological Menstrual Cycle.

    Science.gov (United States)

    Dogan, Mehmet; Yiginer, Omer; Uz, Omer; Kucuk, Ugur; Degirmencioglu, Gokhan; Isilak, Zafer; Uzun, Mehmet; Davulcu, Ezgi

    2016-05-01

    The effects of gender difference on cardiac electrophysiology have been well studied. In this study, we aimed to evaluate the effects of estradiol and progesteron changes occuring in physiological menstrual cycle on ventricular premature beats (VPBs) and cardiac repolarization parameters. Women of reproductive age with VPBs were included into the study group and healthy women were recruited as the control group. During the menstruation period, a 12-lead electrocardiography, blood samples, and 24-hour rhythm Holter were applied to the study group. Similarly, all tests were repeated in the estimated ovulation period (12-14 days before menstruation) by all cases. The study group consisted of 20 women patients with VPB, and the control group of 18 healthy women. While the number of VPB in the menstruation period was 210 beats/day (interquartile range [IQR]: 1,144), it decreased to 86 beats/day (IQR: 251) in the ovulation period with statistical significance (P < 0.05). Average heart rate in the menstruation period was 81.4 ± 10 beats/min and it significantly increased to 84.6 ± 8 beats/min in the ovulation period (P < 0.05). There were no differences in cardiac repolarization parameters in both menstruation and ovulation periods between the study and control groups. Comparing the menstruation and the ovulation periods, J-Tpeak interval, which reflects early repolarization, was shorter in the ovulation period (193 ± 27.7 ms and 201.1 ± 28.6 ms, respectively; P < 0.05). Other repolarization parameters did not show any significant difference. VPB frequency decreases with estradiol peak in the ovulation period. This suggests that estrogen may have protective effects against ventricular arrhythmias. ©2016 Wiley Periodicals, Inc.

  7. Premature Ventricular Contractions (PVCs)

    Science.gov (United States)

    Diseases and Conditions Premature ventricular contractions (PVCs) By Mayo Clinic Staff Premature ventricular contractions (PVCs) are extra, abnormal heartbeats that begin in one of your heart's two ...

  8. Impact of reperfusion therapy and infarct localization on frequency of premature ventricular beats in acute myocardial infarction

    Directory of Open Access Journals (Sweden)

    Davor Horvat

    2015-08-01

    Full Text Available Aim To determine the impact of infarct localization and types of reperfusion therapy on the frequency of ventricular premature beats (VPBs in patients with acute myocardial infarction (AMI and reduced left ventricular ejection fraction (LVEF. Methods A total of 705 patients with acute ST elevation myocardial infarction (STEMI were divided according to the infarct localization (anteroseptal, anterolateral, inferior and posterior and reperfusion therapy (fibrinolysis or percutaneous coronary intervention with stenting into two groups: LVEF45% was a control group. The occurrence of VPBs10 per hour defined as a significant. Results In patients with fibrinolysis therapy and LVEF<45% significant number of VPBs were in anteroseptal (p=0.017, anterolateral (p<0.001 and posterior AMI (p<0.001, but in patients with percutaneous coronary intervention (PCI and LVEF<45% significant number of VPBs were only in anteroseptal AMI (p=0.001 localization. Conclusion In patients with reduced ejection fraction in AMI, treatment with PCI method has a better antiarrhythmic effect compared to fibrinolysis treatment.

  9. Relationship between ischemic area of coronary heart disease and origin part of ventricular premature beat%冠心病缺血区与室性早搏起源部位之间的关系

    Institute of Scientific and Technical Information of China (English)

    宋红艳; 刘相丽; 许纲

    2012-01-01

    目的 探讨冠心病与室性心律失常的关系.方法 对行冠脉造影并行Holter检查者根据造影结果分成阴性组和阳性组,以冠状动脉狭窄大于或等于70%者为阳性.分析两组Holter结果,主要是分析其室性心律失常数量、形态,记录年龄、性别、高血压史、糖尿病史、心脏彩超及室早治疗方法等.结果 冠心病室性心律失常合并高血压、糖尿病者多于特发性室性早搏,室早消融比例及室早次数多于特发性室早(P<0.05).结论 冠心病室早患者有自身的特点,对其治疗有一定指导意义.%Objective To investigate the relationship between ventricular arrhythmias and coronary heart disease(CHD). Methods The patients who underwent coronary angigraphy(CAG) and Holter were enrolled in the study. All patients were divided into negative and positive groups according to the results of CAG. The stenosis of coronary artery≥70% was positive. The Holter results, age,sex, history of hypertension and diabetes mellitus(DM) ,echocardiographic examination, therapeutic measures were analyzed in the two groups. Results The CHD patients with ventricular arrhythmias complicating hypertension and DM were more than those with idiopatic ventricular premature beat, so did the ratio of catheter ablation and the frequency of ventricular premature beat(P<0. 05). Conclusion The CHD patients complicating ventricular premature beats have own characteristics, which has some guidance significance to choose therapy.

  10. Ablation of frequent premature ventricular complex in an athlete.

    Science.gov (United States)

    Grazioli, G; Fernández-Armenta, J; Prat, S; Berruezo, A; Brugada, J; Sitges, M

    2015-12-01

    Premature ventricular complex are common findings in the exam of many athletes. There is no extensive scientific evidence in the management of this situation particularly when associated with borderline contractile function of the left ventricle. In this case report, we present a 35-year-old asymptomatic healthy athlete with high incidence (over 10,000 beats in 24 h) of premature ventricular complex and left ventricular dilatation with dysfunction, which persisted after a resting period of 6 months without training. We performed radiofrequency ablation of the premature ventricular complex focus. After 1-year follow-up, he was asymptomatic without arrhythmia and the left ventricle normalized its size and function as shown by echocardiogram and cardiac magnetic resonance.

  11. 人性化护理在良性频发性室性早搏患者中的应用分析%Application of Benign Frequent Ventricular Premature Beats Patients Humanistic Nursing Care

    Institute of Scientific and Technical Information of China (English)

    亓莲

    2015-01-01

    Objective To analysis of humanized nursing for benign frequent clinical outcome in patients with ventricular premature beat. Methods From 2011 February to 2013 August in our hospital were benign frequent ventricular premature beat in 42 patients during the period from admission to discharge, patients taking the humanized nursing intervention on the patients, nursing and observation of the therapeutic effect and nursing satisfaction effect, etc. Results The 42 cases of patients after treatment and careful nursing is all better discharge. Patients on hospital environment satisfaction is 97.62%, on the nursing satisfaction is 100%, on the nursing technique level of satisfaction is 95.24%. Conclusion Humanistic nursing care for patients with benign frequent ventricular extrasystole to good effect, improved the quality of nursing and nursing satisfaction, is worth in clinical application.%目的:分析人性化护理对良性频发性室性早搏患者的临床效果。方法选取2011年2月至2013年8月本院收治的良性频发性室性早搏患者42例,从患者入院到出院期间对其采取人性化护理干预,观察患者的治疗效果和护理效果、护理满意度等。结果本组42例患者经过治疗和精心护理已全部病情好转出院。患者对住院环境的满意度为97.62%,对护理服务态度满意度为100%,对护理技术水平的满意度为95.24%。结论人性化护理对于良性频发性室性早搏患者的效果良好,提高了护理质量和护理满意度,值得临床广泛应用。

  12. Premature ventricular contractions associated with isotretinoin use.

    Science.gov (United States)

    Alan, Sevil; Ünal, Betül; Yildirim, Aytül

    2016-01-01

    Isotretinoin has been considered a unique drug for acne treatment. However, it is associated with numerous adverse effects. Isotretinoin can trigger premature ventricular contractions. This report describes a 33-year-old-woman who presented with palpitations for 1 week while undergoing 1-month isotretinoin treatment for mild-moderate facial acne. An electrocardiogram and Holter monitoring showed premature ventricular contractions during isotretinoin (Roaccutane, Roche) treatment. Isotretinoin-related premature ventricular contractions were strongly suggested in this case due to the existence of documented premature ventricular contractions on electrocardiograms and the disappearance of these premature ventricular contractions two weeks after termination of the treatment To the authors' knowledge, there has been 1 reported case of premature ventricular contractions linked to isotretinoin use; this report describes a second such case.

  13. Premature ventricular contractions associated with isotretinoin use*

    Science.gov (United States)

    Alan, Sevil; Ünal, Betül; Yildirim, Aytül

    2016-01-01

    Isotretinoin has been considered a unique drug for acne treatment. However, it is associated with numerous adverse effects. Isotretinoin can trigger premature ventricular contractions. This report describes a 33-year-old-woman who presented with palpitations for 1 week while undergoing 1-month isotretinoin treatment for mild-moderate facial acne. An electrocardiogram and Holter monitoring showed premature ventricular contractions during isotretinoin (Roaccutane, Roche) treatment. Isotretinoin-related premature ventricular contractions were strongly suggested in this case due to the existence of documented premature ventricular contractions on electrocardiograms and the disappearance of these premature ventricular contractions two weeks after termination of the treatment To the authors' knowledge, there has been 1 reported case of premature ventricular contractions linked to isotretinoin use; this report describes a second such case. PMID:28099609

  14. The Clinical Sigfificance of QRS-T Waves in Ventricular Premature Beat by Fuzzy Differentiation%模糊差异鉴别对室性早搏QRS-T波形态的临床意义

    Institute of Scientific and Technical Information of China (English)

    吴达; 俞致远; 祝健

    2000-01-01

    Electrocardiograms (ECG)were collected in 895 cases of simple ventricular prematurebeat(VP3) and 18 cases of ventricuiar premature beat with ventricular tachycardia (VT); QRS-Twaves in ECG were measured and then handled by fuzzy set theory and fuzzy differentiationmethod. It was found that a widened QRS complex, especially with the duration of ≥ 0.16 s.indicated a greater possibility of myocardial damage. This finding is in accord with the resultsderived from classical statistical analysis, but shows some differences with the authoriativetraditional differentiation method suggested by Schamroth in the early 1980 s.%根据模糊集理论和模糊差异鉴别方法,对895例单纯室性早搏和18例室性早搏伴室性心动过速心电图的QRS-T波进行测量并作模糊数据处理,发现QRS波增宽,尤其是当时限≥0.16 s时,存在心肌损害的可能性越大.这一结论与用经典数理统计方法处理所得结论一致,但与80年代初由Schamroth所提出的权威的传统鉴别方法的结论有差异.

  15. 特发性室早气阴两虚证患者自主神经功能的变化%Changes of Autonomic Nerve Function in Premature Ventricular Contraction Beats Patients with Deficiency of both Qi and Yin

    Institute of Scientific and Technical Information of China (English)

    阮小芬; 王肖龙; 张一乐; 徐燕; 龚菊芬; 吴昉怡

    2013-01-01

    目的 探讨气阴两虚证室早患者自主神经功能变化的特点.方法 与30例健康对照组相比较,分析41例室早患者自主神经功能各项指标变化,及室早、中医证候与自主神经功能的相关性.结果 室早组患者的SDANN、rMSSD、PNN50显著降低,室早患者中医证候积分与rMSSD、PNN50显著负相关.结论 气阴两虚证室早患者存在迷走神经功能显著降低及交感神经功能亢进,室早临床症状产生与迷走神经功能低下相关.%Objective: To observe the characteristics of autonomic nerve function in premature ventricular contraction beats(PVC) patients. Methods: Compared with 30 healthy controls,the autonomic nervous function of 41 cases PVC patients and the relationship between ventricular premature, the clinical symptoms and autonomic nervous function were analysed. Results: SDANN, rMSSD, and PNN50 were significantly lower in patients with PVC. TCM syndrome and rMSSD, PNN50 was significantly negative correlation. Conclusions: The vagus nerve function are decreased and the sympathetic nerve functionin is hyperthyroidism in PVC patients of both deficiency qi and Yin. clinical symptoms have associated with the vagus nerve function.

  16. Premature Ventricular Complexes and Premature Ventricular Complex Induced Cardiomyopathy.

    Science.gov (United States)

    Latchamsetty, Rakesh; Bogun, Frank

    2015-09-01

    Presentation, prognosis, and management of premature ventricular complexes (PVCs) vary significantly among patients and depend on PVC characteristics as well as patient comorbidities. Presentation can range from incidental discovery in an asymptomatic patient to debilitating heart failure. Prognosis depends on, among other factors, the presence or absence of structural heart disease, PVC burden and other factors detailed in this review. Our understanding of the clinical significance of frequent PVCs, particularly as it relates to development of cardiomyopathy, has advanced greatly in the past decade. In this article, we explore the mechanisms governing PVC initiation and discuss prevalence and frequency of PVCs in the general population. We also explore prognostic implications based on PVC frequency as well as the presence or absence of underlying heart disease. We then take a focused look at PVC-induced cardiomyopathy and identify predictors for developing cardiomyopathy. Finally, we discuss clinical evaluation and management of patients presenting with frequent PVCs. Management can include clinical observation, addressing reversible causes, lifestyle modification, pharmacotherapy, or catheter ablation.

  17. Ablation of premature ventricular complexes exclusively guided by three-dimensional noninvasive mapping.

    Science.gov (United States)

    Erkapic, Damir; Neumann, Thomas

    2015-03-01

    Preprocedural detailed characterization of premature ventricular complexes before ablation, currently limited to the 12-lead electrocardiogram, may aid in planning and improve procedural outcomes. This article summarizes current published data on feasibility, accuracy, and impact on clinical outcomes of a novel, three-dimensional, noninvasive, single-beat mapping system (ECVUE, CardioInsight). ECVUE technology offers premature ventricular complex characterization and localization with clinically relevant accuracy and performance superior to the surface electrocardiogram. With its noninvasive and single beat advantages, ECVUE has the potential to simplify mapping, and reduce ablation and procedural time.

  18. Clinical study of acupuncture combined with medicine in the treatment of coronary heart disease complicated with ven-tricular premature beat%针药结合治疗冠心病复杂性室性早搏的临床研究

    Institute of Scientific and Technical Information of China (English)

    陈莘桃; 谭小华; 周全; 马俐; 朱文红; 陆青研; 谢月萍; 吴曙粤

    2015-01-01

    Objective To investigate the effect of acupuncture and medicine combined treatment on coronary heart disease (CHD)complicated with complex ventricular premature beat,and thus provide a new way of significant effect,safe,convenient operation and no adverse reactions for the clinical treatment of coronary heart disease complicated with ventricular premature beat. Methods Ninety-nine coronary heart disease patients complicated with complex ventricular premature beat were divided into Wenxin granule plus acupuncture treatment group,Wenxin granule group and acupuncture group. Patients were all deactivated other antiarrhythmic drugs,but still accepted treatment for primary disease drugs. The three groups were treated for 1 month,the clinical symptoms,electrocardiogram and dynamic electrocardiogram,liver and kidney function were observed. Results The treatment effect of Wenxin granule plus acupuncture treatment group was significantly better than that of Wenxin granule group and acupuncture group,the total effective rate was 90. 9% ;the effect of Wenxin granule group was better than that of acupuncture group,and the effective rate was 63. 6% . Before and after treatment,the effect had significant difference in the Wenxin granule plus acupuncture treatment group and Wenxin granule group(P 0. 05). After treatment,the 24 h dynamic electrocardiogram of ventricular premature beat reduce number of Wenxin granule plus acupuncture treatment group was better than that of Wenxin granule group(P 0.05)。治疗后,24 h 动态心电图室性早搏减少数针药组大于稳心组( P <0.05)及针刺组(P <0.01),且稳心组治疗后24 h 动态心电图室性早搏减少数大于针刺组(P <0.01)。结论针药结合治疗冠心病复杂性室性早搏的效果优于单用药物治疗或针刺治疗,单用药物治疗的结果优于单用针刺治疗。

  19. Catheter ablation of parahisian premature ventricular complex.

    Science.gov (United States)

    Kim, Jun; Kim, Jeong Su; Park, Yong Hyun; Kim, June Hong; Chun, Kook Jin

    2011-12-01

    Catheter ablation is performed in selected patients with a symptomatic premature ventricular complex (PVC) or PVC-induced cardiomyopathy. Ablation of PVC from the His region has a high risk of inducing a complete atrioventricular block. Here we report successful catheter ablation of a parahisian PVC in a 63-year-old man.

  20. LEFT-VENTRICULAR BEAT-TO-BEAT PERFORMANCE IN ATRIAL-FIBRILLATION - CONTRIBUTION OF FRANK-STARLING MECHANISM AFTER SHORT RATHER THAN LONG RR INTERVALS

    NARCIS (Netherlands)

    GOSSELINK, ATM; BLANKSMA, PK; CRIJNS, HJGM; VANGELDER, IC; DEKAM, PJ; HILLEGE, HL; NIEMEIJER, MG; LIE, KI; MEIJLER, FL

    1995-01-01

    Objectives. This study sought to evaluate control mechanisms of the varying left ventricular performance in atrial fibrillation. Background. Atrial fibrillation is characterized by a randomly irregular ventricular response, resulting in continuous variation in left ventricular beat-to-beat mechanica

  1. Beat-to-beat variation in echocardiographic measurements of left ventricular dimensions and function.

    Science.gov (United States)

    Bett, J H; Dryburgh, L G

    1981-03-01

    M-mode echocardiography was used to explore the extent of spontaneous variation in left ventricular dimensions and indices of systolic and diastolic function. Extended records made in 26 subjects at rest were digitized and analyzed by computer. We found considerable beat-to-beat variation, in that measurements of five or more consecutive cycles were necessary to provide representative values for minor axis dimensions, while the degree of scatter for derived indices of function was greater. This has to be recognized when serial echocardiography is used to study the progress of disease or the effects of treatment.

  2. Catheter ablation of a monofocal premature ventricular complex triggering idiopathic ventricular fibrillation.

    Science.gov (United States)

    Takatsuki, S; Mitamura, H; Ogawa, S

    2001-07-01

    A 62 year old man was admitted for evaluation of recurrent episodes of syncope. A surface ECG showed frequent repetitive premature ventricular complexes of right ventricular outflow tract origin. Ventricular fibrillation was inducible by programmed electrical stimulation but otherwise cardiac evaluation was unremarkable. A diagnosis of idiopathic ventricular fibrillation was made and an implantable cardioverter-defibrillator (ICD) was installed. However, spontaneous ventricular fibrillation recurred, requiring repeated ICD discharges. The ventricular fibrillation was reproducibly triggered by a single premature ventricular complex with a specific QRS morphology. Radiofrequency catheter ablation was carried out to eradicate this complex. No ventricular fibrillation has developed after this procedure, and the patient does not require drug treatment.

  3. Scaling behavior and a Markov model for ventricular fibrillation generated by ectopic beats

    Science.gov (United States)

    Hastings, Harold; Evans, Steven; Zaharakis, Alex; Hilaire, Christian

    2006-03-01

    Sudden cardiac death is a major cause of death in the industrialized world, responsible for 300,000 deaths per year in the US. Although the cardiac electrical system normally produces one ventricular activation in response to each stimulus from the sinus node, ``spontaneous'' activations, called premature ventricular contractions (PVCs), can arise in the ventricles themselves, and propagate through the ventricles. Although usually harmless in the absence of underlying disease, PVCs can generate broken wavefronts when they meet gradients of refractoriness generated by other beats. These broken wavefronts may generate spiral waves producing ventricular tachycardia and ultimately degenerate into ventricular fibrillation (VF), causing sudden cardiac death. When does a PVC lead to ventricular fibrillation ? This is a stiff problem, involving time scales from milliseconds to many years. We overcome this problem by developing universal scaling properties and using these rules to drive a Markov process. We find two significant ``amplifiers'' and discuss consequences for variability of VF rates in human populations. We thank Elizabeth Cherry, Flavio Fenton, Anna Gelzer and James Glimm for helpful discussions.

  4. 室性心动过速及顽固性室性早搏的导管消融治疗%Catheter Ablation of Ven tricular Tachycardia and Symptomatic Ventricular Premature Beats.

    Institute of Scientific and Technical Information of China (English)

    郑强荪; 薛玉生; 赵玉; 张录兴; 王毅; 柳荫; 史俊忠; 杨欣国; 杜日映

    2001-01-01

    Clinical results of ventricular tachycardia(VT) and symptomatic ventricula rpremature beats(VPBs) in 67 patients were reviewed retrospectively.Twenty-fou rand forty-three patients received this treatment in the periods from March 1991 to October 1993 and from November 1993 to October 1999,which were termed early stage and late stage,respectively.Direct current catheter ablation (DCCA) and radiofrequency catheter ablation(RFCA) were performed on all patients guided by endocardial activation mapping combined with pace mapping.The success rate in the patients treated by RFCA was significantly lower in the early stage than th at in the late stage(40% vs 95%,P<0.05).The recurrence rate,the incidence of complications and the mean peak CPK concentration were higher in the patients tr eated by DCCA in the early stage than those by RFCA in the late stage(10% vs 2%, P<0.05; 20% vs 5%,P<0.05;1 032±369 U/L vs 163±82 U/L,P<0.05).Among 67 patients,there were 52 patients with idiopathic ventricular tachycardi a(IVT).Right IVT was found in 22 patients,which originated from the right vent ricular outflow tract in 19 (79%).The earliest endocardial activation in the su ccessful target points was 25.3±5.6 ms before the onset of the QRS complex in 21patients during those IVT.Left IVT was found in 26 patients,which originated from the left posterior septum in 21(75%).The earliest endocardial activation was 29.1±6.0 ms before the onset of the QRS complex in 25patients.The isolate dpurkinje potential was recorded in only one patient.The success rate was 94%( 17/18) for IVT by DCCA in the early stage,while 100%(30/30) by RFCA in the late stage.There were 10 patients with VT combined with structural heart disease.Of them,2 received DCCA in the early stage,whose VT was successfully eliminated in 1.The other 8 patients received RFCA in the late stage,whose VT was elimin ated in 6.There were 5 patients with the refractory symptomatic VPBs,which ori ginated from the right outflow tract in 4

  5. Catheter ablation of a polymorphic ventricular tachycardia inducing monofocal premature ventricular complex.

    Science.gov (United States)

    Uemura, Takashi; Yamabe, Hiroshige; Tanaka, Yasuaki; Morihisa, Kenji; Kawano, Hiroaki; Kaikita, Koichi; Sumida, Hitoshi; Sugiyama, Seigo; Ogawa, Hisao

    2008-01-01

    Ventricular tachycardia originating from the right ventricular outflow tract (RVOT) is considered benign, but sometimes it causes polymorphic ventricular tachycardia and ventricular fibrillation, resulting in sudden cardiac death. A 58-year-old woman without structural heart disease was admitted for evaluation of recurrent episodes of syncope. Surface ECG showed frequent repetitive premature ventricular contraction (PVC) of RVOT origin. Polymorphic ventricular tachycardia triggered by the same PVC was documented by Holter ECG during an episode of syncope. Radiofrequency catheter ablation was performed to eradicate this PVC. No polymorphic ventricular tachycardia has developed after the procedure, and the patient has had no recurrence of syncope.

  6. A Case Report of Renal Sympathetic Denervation for the Treatment of Polymorphic Ventricular Premature Complexes

    Science.gov (United States)

    Kiuchi, Márcio Galindo; Vitorio, Frederico Puppim; da Silva, Gustavo Ramalho; Paz, Luis Marcelo Rodrigues; Souto, Gladyston Luiz Lima

    2015-01-01

    Abstract Premature ventricular complexes are very common, appearing most frequently in patients with hypertension, obesity, sleep apnea, and structural heart disease. Sympathetic hyperactivity plays a critical role in the development, maintenance, and aggravation of ventricular arrhythmias. Recently, Armaganijan et al reported the relevance of sympathetic activation in patients with ventricular arrhythmias and suggested a potential role for catheter-based renal sympathetic denervation in reducing the arrhythmic burden. In this report, we describe a 32-year-old hypertensive male patient presenting with a high incidence of polymorphic premature ventricular complexes on a 24 hour Holter monitor. Beginning 1 year prior, the patient experienced episodes of presyncope, syncope, and tachycardia palpitations. The patient was taking losartan 100 mg/day, which kept his blood pressure (BP) under control, and sotalol 160 mg twice daily. Bisoprolol 10 mg/day was used previously but was not successful for controlling the episodes. The 24 hour Holter performed after the onset of sotalol 160 mg twice daily showed a heart rate ranging between 48 (minimum)–78 (average)–119 (maximum) bpm; 14,286 polymorphic premature ventricular complexes; 3 episodes of nonsustained ventricular tachycardia, the largest composed of 4 beats at a rate of 197 bpm; and 14 isolated atrial ectopic beats. Cardiac magnetic resonance imaging with gadolinium perfusion performed at rest and under pharmacological stress with dipyridamole showed increased left atrial internal volume, preserved systolic global biventricular function, and an absence of infarcted or ischemic areas. The patient underwent bilateral renal sympathetic denervation. The only drug used postprocedure was losartan 25 mg/day. Three months after the patient underwent renal sympathetic denervation, the mean BP value dropped to 132/86 mmHg, the mean systolic/diastolic 24 hour ambulatory BP measurement was reduced to 128/83

  7. Left ventricular beat-to-beat performance in atrial fibrillation: Contribution of Frank-Starling mechanism after short rather than long intervals

    NARCIS (Netherlands)

    Gosselink, A.T.M.; Blanksma, P.K.; Crijns, H.J.G.M.; Gelder, I.C. van; Kam, P.J. de; Hillege, H.L.; Niemeijer, M.G.; Lie, K.I.; Meijler, F.L.

    1995-01-01

    This study sought to evaluate control mechanisms of the varying left ventricular performance in atrial fibrillation. Atrial fibrillation is characterized by a randomly irregular ventricular response, resulting in continuous variation in left ventricular beat-to-beat mechanical behavior and hemodynam

  8. Premature ventricular complex-induced chronic cough and cough syncope.

    Science.gov (United States)

    Stec, S; Dabrowska, M; Zaborska, B; Bielicki, P; Maskey-Warzechowska, M; Tarnowski, W; Chazan, R; Kulakowski, P

    2007-08-01

    The present case study reports a case of chronic cough and cough syncope associated with frequent premature ventricular complexes (PVCs). Careful analysis of cough-related symptoms and ECG monitoring led to the suspicion of PVC-induced cough. A coincidence between PVCs and episodes of cough was also documented by a portable multichannel recorder. Moreover, Doppler echocardiography revealed a PVC-induced transient increase in the pulmonary artery blood flow. After exclusion of other possible aetiologies, complete relief of chronic cough and cough syncope was achieved by radiofrequency ablation of the arrhythmogenic focus located in the right ventricular outflow tract. Premature ventricular complexes should be considered as a cause of chronic cough and cough syncope and an interdisciplinary cooperation can lead to successful diagnosis and treatment of this condition.

  9. Robust detection of premature ventricular contractions using sparse signal decomposition and temporal features.

    Science.gov (United States)

    Manikandan, M Sabarimalai; Ramkumar, Barathram; Deshpande, Pranav S; Choudhary, Tilendra

    2015-12-01

    An automated noise-robust premature ventricular contraction (PVC) detection method is proposed based on the sparse signal decomposition, temporal features, and decision rules. In this Letter, the authors exploit sparse expansion of electrocardiogram (ECG) signals on mixed dictionaries for simultaneously enhancing the QRS complex and reducing the influence of tall P and T waves, baseline wanders, and muscle artefacts. They further investigate a set of ten generalised temporal features combined with decision-rule-based detection algorithm for discriminating PVC beats from non-PVC beats. The accuracy and robustness of the proposed method is evaluated using 47 ECG recordings from the MIT/BIH arrhythmia database. Evaluation results show that the proposed method achieves an average sensitivity of 89.69%, and specificity 99.63%. Results further show that the proposed decision-rule-based algorithm with ten generalised features can accurately detect different patterns of PVC beats (uniform and multiform, couplets, triplets, and ventricular tachycardia) in presence of other normal and abnormal heartbeats.

  10. Evaluation of global and regional left ventricular systolic function in patients with frequent isolated premature ventricular complexes from the right ventricular outflow tract

    Institute of Scientific and Technical Information of China (English)

    YAO Jing; XU Jing; YONG Yong-hong; CAO Ke-jiang; CHEN Shao-liang; XU Di

    2012-01-01

    Background Frequent premature ventricular complexes from the right ventricular outflow tract (RVOT-PVCs) are associated with left ventricular dysfunction.This study adopted two-dimensional speckle tracking imaging to evaluate global and regional left ventricular myocardial function in patients with frequent RVOT-PVCs.Methods This study included 30 patients with frequent RVOT-PVCs and 30 healthy subjects.Aortic systolic velocity-time integral (AoVTI) and myocardium strain in circumferential (CS),radial (RS) and longitudinal (LS) directions were evaluated by conventional echocardiography and speckle tracking imaging.All values of patients with RVOT-PVCs were recorded during sinus (PVC-S) and PVC beats (PVC-V).Results Significant differences were demonstrated in global CS,RS and LS between the control subjects and the PVC-V (CS:(17.46±2.48)% vs.(11.52±3.28)%,RS:(48.26±10.20)% vs.(20.92±9.78)%,LS:(19.89±2.62)% vs.(11.79±3.66)%,P <0.01),and in segmental RS and LS of nearly all the left ventricular segments.Statistical differences in segmental CS between the PVC-V and the control subjects were only observed in anterior,anteroseptal and septal segments (only seen in anteroseptal and septal segments at apex).Furthermore,V/S AoVTI (AoVTI during the PVC beat divided by AoVTI during the sinus beat,then multiplied by 100%) correlated with coupling interval (r=0.67,P <0.001) and global strain (CS:r=0.48,P=0.007; RS:r=0.65,P <0.001; LS:r=0.65,P <0.001).Conclusions Frequent RVOT-PVCs can induce global and regional left ventricular systolic dysfunction.The reduction of hemodynamic parameters relates to the coupling interval and the global systolic function.

  11. Calcium release near l-type calcium channels promotes beat-to-beat variability in ventricular myocytes from the chronic AV block dog

    NARCIS (Netherlands)

    Antoons, G.; Johnson, Daniel M; Dries, Eef; Santiago, Demetrio J; Ozdemir, Semir; Lenaerts, Ilse; Beekman, Jet D M; Houtman, Marien J C; Sipido, Karin R; Vos, Marc A

    2015-01-01

    Beat-to-beat variability of ventricular repolarization (BVR) has been proposed as a strong predictor of Torsades de Pointes (TdP). BVR is also observed at the myocyte level, and a number of studies have shown the importance of calcium handling in influencing this parameter. The chronic AV block (CAV

  12. Fast rate (≥ 250 beats/min) right ventricular burst stimulation is useful for ventricular tachycardia induction in arrhythmogenic right ventricular cardiomyopathy

    Institute of Scientific and Technical Information of China (English)

    Ling-Min WU; Jing-Ru BAO; Yan YAO; Bing-Bo HOU; Li-Hui ZHENG; Shu ZHANG

    2016-01-01

    Background One of the major challenges in arrhythmogenic right ventricular cardiomyopathy (ARVC) ablation is ventricular tachy-cardia (VT) non-inducibility. The study aimed to assess whether fast rate (≥ 250 beats/min) right ventricular burst stimulation was useful for VT induction in patients with ARVC.Methods Ninety-one consecutive ARVC patients with clinical sustained VT that underwent electro-physiological study were enrolled. The stimulation protocol was implemented at both right ventricular apex and outflow tract as follows: Step A, up to double extra-stimuli; Step B, incremental stimulation with low rate (< 250 beats/min); Step C, burst stimulation with fast rate (≥ 250 beats/min); Step D, repeated all steps above with intravenous infusion of isoproterenol.Results A total of 76 patients had inducible VT (83.5%), among which 49 were induced by Step C, 15 were induced by Step B, 8 and 4 by Step A and D, respectively. Clinical VTs were induced in 60 patients (65.9%). Only two spontaneously ceased ventricular fibrillations were induced by Step C. Multivariate analysis showed that a narrower baseline QRS duration under sinus rhythm was independently associated with VT non-inducibility (OR: 1.1; 95% CI: 1.0–1.1;P = 0.019).ConclusionFast rate (≥ 250 beats/min) right ventricular burst stimulation provides a useful supplemental method for VT induction in ARVC patients.

  13. Premature Ventricular Contractions (PVCs Induced by Administration of Cilostazol after Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Lihua Zhong

    2013-02-01

    Full Text Available Cilostazol is a phosphodiesterase III inhibitor, which was approved by FDA (food and drug administration for intermittent claudication in 1999. What made it known to cardiologists is the Cilostazol for Restenosis Trial (CREST, in which cilostazol was shown to significantly lower binary restenosis rate. Here we reported one case of acquired premature ventricular contractions (PVCs during taking cilostazol. A 68-year-old male patient was diagnosed acute myocardial infarction and given percutaneous coronary intervention (PCI. It turned out there was thrombi in the distal right coronary artery. The patient was discharged taking cilostazol (100mg Bid together with aspirin and clopidogrel. On follow-up, there were PVCs coming up (more than 27000 beats in 24-hour electrocardiography and cilostazol was discontinued afterwards. After taking metoprolol (25 mg, Tid for one week, the PVCs were decreased significantly, 600 beats/24 hours. In our case, the PVCs are obviously related to cilostazol and probably the safety of cilostazol in patients having a history of myocardial infarction or malignant arrhythmias should be reevaluated.

  14. Automatic diagnosis of premature ventricular contraction based on Lyapunov exponents and LVQ neural network.

    Science.gov (United States)

    Liu, Xiuling; Du, Haiman; Wang, Guanglei; Zhou, Suiping; Zhang, Hong

    2015-10-01

    Premature ventricular contraction (PVC) is a common type of abnormal heartbeat. Without early diagnosis and proper treatment, PVC may result in serious harms. Diagnosis of PVC is of great importance in goal-directed treatment and preoperation prognosis. This paper proposes a novel diagnostic method for PVC based on Lyapunov exponents of electrocardiogram (ECG) beats. The methodology consists of preprocessing, feature extraction and classification integrated into the system. PVC beats can be classified and differentiated from other types of abnormal heartbeats by analyzing Lyapunov exponents and training a learning vector quantization (LVQ) neural network. Our algorithm can obtain a good diagnostic result with little features by using single lead ECG data. The sensitivity, positive predictability, and the overall accuracy of the automatic diagnosis of PVC is 90.26%, 92.31%, and 98.90%, respectively. The effectiveness of the new method is validated through extensive tests using data from MIT-BIH database. The experimental results show that the proposed method is efficient and robust.

  15. Changes in intracellular calcium concentration influence beat-to-beat variability of action potential duration in canine ventricular myocytes.

    Science.gov (United States)

    Kistamas, K; Szentandrassy, N; Hegyi, B; Vaczi, K; Ruzsnavszky, F; Horvath, B; Banyasz, T; Nanasi, P P; Magyar, J

    2015-02-01

    The aim of the present work was to study the influence of changes in intracellular calcium concentration ([Ca(2+)]i) on beat-to-beat variability (short term variability, SV) of action potential duration (APD) in isolated canine ventricular cardiomyocytes. Series of action potentials were recorded from enzymatically isolated canine ventricular cells using conventional microelectrode technique. Drug effects on SV were evaluated as relative SV changes determined by plotting the drug-induced changes in SV against corresponding changes in APD and comparing these data to the exponential SV-APD function obtained with inward and outward current injections. Exposure of myocytes to the Ca(2+) chelator BAPTA-AM (5 μM) decreased, while Ca(2+) ionophore A23187 (1 μM) increased the magnitude of relative SV. Both effects were primarily due to the concomitant changes in APD. Relative SV was reduced by BAPTA-AM under various experimental conditions including pretreatment with veratridine, BAY K8644, dofetilide or E-4031. Contribution of transient changes of [Ca(2+)]i due to Ca(2+) released from the sarcoplasmic reticulum (SR) was studied using 10 μM ryanodine and 1 μM cyclopiazonic acid: relative SV was reduced by both agents. Inhibition of the Na(+)-Ca(2+) exchanger by 1 μM SEA0400 increased relative SV. It is concluded that elevation of [Ca(2+)]i increases relative SV significantly. More importantly, Ca(2+) released from the SR is an important component of this effect.

  16. Single-beat noninvasive imaging of ventricular endocardial and epicardial activation in patients undergoing CRT.

    Directory of Open Access Journals (Sweden)

    Thomas Berger

    Full Text Available BACKGROUND: Little is known about the effect of cardiac resynchronization therapy (CRT on endo- and epicardial ventricular activation. Noninvasive imaging of cardiac electrophysiology (NICE is a novel imaging tool for visualization of both epi- and endocardial ventricular electrical activation. METHODOLOGY/PRINCIPAL FINDINGS: NICE was performed in ten patients with congestive heart failure (CHF undergoing CRT and in ten patients without structural heart disease (control group. NICE is a fusion of data from high-resolution ECG mapping with a model of the patient's individual cardiothoracic anatomy created from magnetic resonance imaging. Beat-to-beat endocardial and epicardial ventricular activation sequences were computed during native rhythm as well as during ventricular pacing using a bidomain theory-based heart model to solve the related inverse problem. During right ventricular (RV pacing control patients showed a deterioration of the ventricular activation sequence similar to the intrinsic activation pattern of CHF patients. Left ventricular propagation velocities were significantly decreased in CHF patients as compared to the control group (1.6±0.4 versus 2.1±0.5 m/sec; p<0.05. CHF patients showed right-to-left septal activation with the latest activation epicardially in the lateral wall of the left ventricle. Biventricular pacing resulted in a resynchronization of the ventricular activation sequence and in a marked decrease of total LV activation duration as compared to intrinsic conduction and RV pacing (129±16 versus 157±28 and 173±25 ms; both p<0.05. CONCLUSIONS/SIGNIFICANCE: Endocardial and epicardial ventricular activation can be visualized noninvasively by NICE. Identification of individual ventricular activation properties may help identify responders to CRT and to further improve response to CRT by facilitating a patient-specific lead placement and device programming.

  17. Single-Beat Noninvasive Imaging of Ventricular Endocardial and Epicardial Activation in Patients Undergoing CRT

    Science.gov (United States)

    Berger, Thomas; Pfeifer, Bernhard; Hanser, Friedrich F.; Hintringer, Florian; Fischer, Gerald; Netzer, Michael; Trieb, Thomas; Stuehlinger, Markus; Dichtl, Wolfgang; Baumgartner, Christian; Pachinger, Otmar; Seger, Michael

    2011-01-01

    Background Little is known about the effect of cardiac resynchronization therapy (CRT) on endo- and epicardial ventricular activation. Noninvasive imaging of cardiac electrophysiology (NICE) is a novel imaging tool for visualization of both epi- and endocardial ventricular electrical activation. Methodology/Principal Findings NICE was performed in ten patients with congestive heart failure (CHF) undergoing CRT and in ten patients without structural heart disease (control group). NICE is a fusion of data from high-resolution ECG mapping with a model of the patient's individual cardiothoracic anatomy created from magnetic resonance imaging. Beat-to-beat endocardial and epicardial ventricular activation sequences were computed during native rhythm as well as during ventricular pacing using a bidomain theory-based heart model to solve the related inverse problem. During right ventricular (RV) pacing control patients showed a deterioration of the ventricular activation sequence similar to the intrinsic activation pattern of CHF patients. Left ventricular propagation velocities were significantly decreased in CHF patients as compared to the control group (1.6±0.4 versus 2.1±0.5 m/sec; p<0.05). CHF patients showed right-to-left septal activation with the latest activation epicardially in the lateral wall of the left ventricle. Biventricular pacing resulted in a resynchronization of the ventricular activation sequence and in a marked decrease of total LV activation duration as compared to intrinsic conduction and RV pacing (129±16 versus 157±28 and 173±25 ms; both p<0.05). Conclusions/Significance Endocardial and epicardial ventricular activation can be visualized noninvasively by NICE. Identification of individual ventricular activation properties may help identify responders to CRT and to further improve response to CRT by facilitating a patient-specific lead placement and device programming. PMID:21298045

  18. Finding features for real-time premature ventricular contraction detection using a fuzzy neural network system.

    Science.gov (United States)

    Lim, Joon S

    2009-03-01

    Fuzzy neural networks (FNNs) have been successfully applied to generate predictive rules for medical or diagnostic data. This brief presents an approach to detect premature ventricular contractions (PVCs) using the neural network with weighted fuzzy membership functions (NEWFMs). The NEWFM classifies normal and PVC beats by the trained bounded sum of weighted fuzzy membership functions (BSWFMs) using wavelet transformed coefficients from the MIT-BIH PVC database. The eight generalized coefficients, locally related to the time signal, are extracted by the nonoverlap area distribution measurement method. The eight generalized coefficients are used for the three PVC data sets with reliable accuracy rates of 99.80%, 99.21%, and 98.78%, respectively, which means that the selected features are less dependent on the data sets. It is shown that the locations of the eight features are not only around the QRS complex that represents ventricular depolarization in the electrocardiogram (ECG) containing a Q wave, an R wave, and an S wave, but also the QR segment from the Q wave to the R wave has more discriminate information than the RS segment from the R wave to the S wave. The BSWFMs of the eight features trained by NEWFM are shown visually, which makes the features explicitly interpretable. Since each BSWFM combines multiple weighted fuzzy membership functions into one using the bounded sum, the eight small-sized BSWFMs can realize real-time PVC detection in a mobile environment.

  19. Reversal of premature ventricular complex-induced cardiomyopathy following successful radiofrequency catheter ablation.

    Science.gov (United States)

    Efremidis, Michalis; Letsas, Konstantinos P; Sideris, Antonios; Kardaras, Fotios

    2008-06-01

    Premature ventricular complex (PVC)-induced cardiomyopathy is an underappreciated cause of left-ventricular (LV) dysfunction. The present report describes the case of an elderly man with a very high burden of monomorphic PVCs and LV dysfunction. Elimination of the left ventricular focus following radiofrequency catheter ablation resulted in reversal of cardiomyopathy.

  20. Comparative usefulness of beat-to-beat QT dispersion and QT interval fluctuations for identifying patients with organic heart disease at risk for ventricular arrhythmias.

    Science.gov (United States)

    Galeano, Erdulfo J; Yoshida, Akihiro; Ohnishi, Yoshio; Okajima, Katsunori; Ishida, Akihiko; Kitamura, Hidetsuna; Kubo, Shinya; Yokoyama, Mitsuhiro

    2003-02-01

    The comparative usefulness of 10 min of beat-to-beat 12-lead QT dispersion (QTd) and QT interval variability index (QTVI) analysis for identifying patients with organic heart disease (OHD) at risk for ventricular arrhythmias was assessed in 86 subjects: 54 had OHD without a history of ventricular arrhythmias, 15 had OHD with documented ventricular tachycardia, and there were 17 controls. The following parameters were analyzed among the groups: (1) the average QTd (mean QTd), (2) the difference between the maximum and minimum QTd observed over the recording time (QTd variation), (3) the maximum difference of QTd between consecutive beats (QTd maximum), (4) the QTd standard deviation (QTd variability), and (5) QTVI, calculated in lead I or II according to an established formula: log 10 [(QTv/QTm2) / (HRv/HRm2)]. All the analyzed parameters were significantly increased in the patients with and without ventricular tachycardia when compared with the controls. QTd variation, QTd maximum and QTd variability were the only variables that remained significantly increased in the group of patients with documented ventricular tachycardia, compared with those without arrhythmia. Thus, beat-to-beat fluctuations of both the QT interval and QTd may be markers of temporal electrical instability in patients with OHD.

  1. Determinants of beat-to-beat variability of repolarization duration in the canine ventricular myocyte: a computational analysis.

    Directory of Open Access Journals (Sweden)

    Jordi Heijman

    Full Text Available Beat-to-beat variability of repolarization duration (BVR is an intrinsic characteristic of cardiac function and a better marker of proarrhythmia than repolarization prolongation alone. The ionic mechanisms underlying baseline BVR in physiological conditions, its rate dependence, and the factors contributing to increased BVR in pathologies remain incompletely understood. Here, we employed computer modeling to provide novel insights into the subcellular mechanisms of BVR under physiological conditions and during simulated drug-induced repolarization prolongation, mimicking long-QT syndromes type 1, 2, and 3. We developed stochastic implementations of 13 major ionic currents and fluxes in a model of canine ventricular-myocyte electrophysiology. Combined stochastic gating of these components resulted in short- and long-term variability, consistent with experimental data from isolated canine ventricular myocytes. The model indicated that the magnitude of stochastic fluctuations is rate dependent due to the rate dependence of action-potential (AP duration (APD. This process (the "active" component and the intrinsic nonlinear relationship between membrane current and APD ("intrinsic component" contribute to the rate dependence of BVR. We identified a major role in physiological BVR for stochastic gating of the persistent Na(+ current (INa and rapidly activating delayed-rectifier K(+ current (IKr. Inhibition of IKr or augmentation of INa significantly increased BVR, whereas subsequent β-adrenergic receptor stimulation reduced it, similar to experimental findings in isolated myocytes. In contrast, β-adrenergic stimulation increased BVR in simulated long-QT syndrome type 1. In addition to stochastic channel gating, AP morphology, APD, and beat-to-beat variations in Ca(2+ were found to modulate single-cell BVR. Cell-to-cell coupling decreased BVR and this was more pronounced when a model cell with increased BVR was coupled to a model cell with normal BVR

  2. Use of Catheter Ablation in the Treatment of Ventricular Tachycardia Triggered by Premature Ventricular Contraction

    Directory of Open Access Journals (Sweden)

    Isao Kato, MD

    2006-01-01

    Full Text Available A 50-year-old man who had suffered from old myocardial infarction presented with an episode of syncope. DC shock was required for the interruption of frequent pleomorphic ventricular tachycardia (VT. Although the treatment for heart failure decreased the frequency of VT attacks, hemodynamically unstable VT occurred several times. A 12-lead Holter electrocardiogram was used to determine the triggering premature ventricular contraction (PVC and catheter ablation was performed by targeting this PVC. The site of origin of the triggering PVC was considered to be located between damaged cardiac muscle and intact Purkinje's fiber. No episode of PVC and VT was observed after a few days of ablation. An implantable cardioverter defibrillator was implanted but VT did not recur for more than 20 months.

  3. Ventricular fibrillation induced by a radiofrequency energy delivery for idiopathic premature ventricular contractions arising from the left ventricular anterior papillary muscle.

    Science.gov (United States)

    Yamada, Takumi; McElderry, H Thomas; Allred, James D; Doppalapudi, Harish; Kay, G Neal

    2009-08-01

    A 73-year-old man with idiopathic premature ventricular contractions (PVCs) underwent electrophysiological testing. Left ventricular activation mapping revealed a focal mechanism of the PVCs with the earliest activation on the anterior papillary muscle (APM). Irrigated radiofrequency (RF) current delivered at that site induced a cluster of non-sustained ventricular tachycardia episodes with the same QRS morphology as the PVCs, followed by ventricular fibrillation (VF). The APM might have served as an abnormal automatic trigger and driver for the VF occurrence. Ventricular fibrillation may occur as a complication during RF catheter ablation of papillary muscle ventricular arrhythmias even if the clinical arrhythmia is limited to PVCs.

  4. Examining cross-database global training to evaluate five different methods for ventricular beat classification.

    Science.gov (United States)

    Chudácek, V; Georgoulas, G; Lhotská, L; Stylios, C; Petrík, M; Cepek, M

    2009-07-01

    The detection of ventricular beats in the holter recording is a task of great importance since it can direct clinicians toward the parts of the electrocardiogram record that might be crucial for determining the final diagnosis. Although there already exists a fair amount of research work dealing with ventricular beat detection in holter recordings, the vast majority uses a local training approach, which is highly disputable from the point of view of any practical-real-life-application. In this paper, we compare five well-known methods: a classical decision tree approach and its variant with fuzzy rules, a self-organizing map clustering method with template matching for classification, a back-propagation neural network and a support vector machine classifier, all examined using the same global cross-database approach for training and testing. For this task two databases were used-the MIT-BIH database and the AHA database. Both databases are required for testing any newly developed algorithms for holter beat classification that is going to be deployed in the EU market. According to cross-database global training, when the classifier is trained with the beats from the records of one database then the records from the other database are used for testing. The results of all the methods are compared and evaluated using the measures of sensitivity and specificity. The support vector machine classifier is the best classifier from the five we tested, achieving an average sensitivity of 87.20% and an average specificity of 91.57%, which outperforms nearly all the published algorithms when applied in the context of a similar global training approach.

  5. Semisupervised ECG Ventricular Beat Classification With Novelty Detection Based on Switching Kalman Filters.

    Science.gov (United States)

    Oster, Julien; Behar, Joachim; Sayadi, Omid; Nemati, Shamim; Johnson, Alistair E W; Clifford, Gari D

    2015-09-01

    Automatic processing and accurate diagnosis of pathological electrocardiogram (ECG) signals remains a challenge. As long-term ECG recordings continue to increase in prevalence, driven partly by the ease of remote monitoring technology usage, the need to automate ECG analysis continues to grow. In previous studies, a model-based ECG filtering approach to ECG data from healthy subjects has been applied to facilitate accurate online filtering and analysis of physiological signals. We propose an extension of this approach, which models not only normal and ventricular heartbeats, but also morphologies not previously encountered. A switching Kalman filter approach is introduced to enable the automatic selection of the most likely mode (beat type), while simultaneously filtering the signal using appropriate prior knowledge. Novelty detection is also made possible by incorporating a third mode for the detection of unknown (not previously observed) morphologies, and denoted as X-factor. This new approach is compared to state-of-the-art techniques for the ventricular heartbeat classification in the MIT-BIH arrhythmia and Incart databases. F1 scores of 98.3% and 99.5% were found on each database, respectively, which are superior to other published algorithms' results reported on the same databases. Only 3% of all the beats were discarded as X-factor, and the majority of these beats contained high levels of noise. The proposed technique demonstrates accurate beat classification in the presence of previously unseen (and unlearned) morphologies and noise, and provides an automated method for morphological analysis of arbitrary (unknown) ECG leads.

  6. Radiofrequency catheter ablation of idiopathic ventricular tachycardia and symptomatic premature ventricular contraction originating from valve annulus

    Institute of Scientific and Technical Information of China (English)

    WU Xiao-yu; LIANG Zhao-guang; TAN Zhen; GU Hong-yue; ZHANG Shu; LI Wei-min

    2008-01-01

    Background Radiofrequency catheter ablation (RFCA) has been established as an effective and curative therapy for ventricular tachycardia (VT) and severely symptomatic premature ventricular contraction (PVC) from the outflow tract in structurally normal hearts.This study aimed to investigate electrophysiologic characteristics and effects of RFCA for patients with idiopathic VT and symptomatic PVC originating from the valve annulus.Methods Characteristics of body surface electrocardiogram (ECG) and endocardiogram in a successful RFCA target were analyzed in 16 patients with idiopathic VT and symptomatic PVC originating from the valve annulus.Additionally,the ECG characteristics of vr or PVC were compared with those of manifest Wolff-Parkinson-White (WPW) syndrome originating from the same site of origin in 15 patients.Results Thirteen patients were successful,2 recurrent and 1 failed.The recurrent cases underwent successful ablation the second time guided by the Ensite 3000 mapping system.In all patients with the WPW syndrome,the characteristics of QRS morphology were well matched with those of the VT and PVC that originated from corresponding sites of origin.Conclusions RFCA is an effective curative therapy for VT and symptomatic PVC originating from the valve annulus.There are specific characteristics in ECG and the ablation site could be located by means of the WPW syndrome accessory pathway's algorithm.

  7. Model driven quantification of left ventricular function from sparse single-beat 3D echocardiography.

    Science.gov (United States)

    Ma, Meng; van Stralen, Marijn; Reiber, Johan H C; Bosch, Johan G; Lelieveldt, Boudewijn P F

    2010-08-01

    This paper presents a novel model based segmentation technique for quantification of left ventricular (LV) function from sparse single-beat 3D echocardiographic data acquired with a fast rotating ultrasound (FRU) transducer. This transducer captures cardiac anatomy in a sparse set of radially sampled, curved cross-sections within a single cardiac cycle. The method employs a 3D Active Shape Model of the left ventricle (LV) in combination with local appearance models as prior knowledge to steer the segmentation. A set of local appearance patches generate the model update points for fitting the model to the LV in the curved FRU cross-sections. Updates are then propagated over the dense 3D model mesh to overcome correspondence problems due to the data sparsity, whereas the 3D Active Shape Model serves to retain the plausibility of the generated shape. Leave-one-out cross-validation was carried out on single-beat FRU data from 28 patients suffering from various cardiac pathologies. Detection succeeded in 24 cases, and failed in 4 cases due to large dropouts in echo signal. For the successful 24 cases, detection yielded Point to Point errors of 3.1+/-1.1mm, Point to Surface errors of 1.7+/-0.9mm and an EF error of 7.3+/-4.9%. Comparison of fitting on single-beat versus denser multi-beat data showed a similar performance for both types of data irrespective of frame angles of the intersections. Robustness tests with respect to different model initializations showed acceptable performance for initial positions within a range of 26mm for displacement and 12 degrees for orientation. Furthermore, a comparison study between the proposed method and global LV function measured from MR studies of the same patients showed an underestimation of volumes estimated from echocardiographic data compared to MR derived volumes, similar to other results reported in literature. All experiments demonstrate that the proposed method combines robustness with respect to initialization with an

  8. Potassium and magnesium distribution, ECG changes, and ventricular ectopic beats during beta 2-adrenergic stimulation with terbutaline in healthy subjects

    DEFF Research Database (Denmark)

    Tveskov, C; Djurhuus, M S; Klitgaard, N A

    1994-01-01

    OBJECTIVE: To study the effect of intravenous (i.v.) terbutaline on potassium (K) and magnesium (Mg) distribution, ECG changes, and prevalence of ventricular ectopic beats in healthy subjects. DESIGN: Randomized double-blind, placebo-controlled crossover. Subjects received either placebo or terbu......OBJECTIVE: To study the effect of intravenous (i.v.) terbutaline on potassium (K) and magnesium (Mg) distribution, ECG changes, and prevalence of ventricular ectopic beats in healthy subjects. DESIGN: Randomized double-blind, placebo-controlled crossover. Subjects received either placebo......-potassium pump number. Urinary excretion of potassium and magnesium. ECG changes (T-wave and QTC interval) and the number of ventricular ectopic beats. MAIN RESULTS: Terbutaline produced an immediate decrease in serum potassium level from 4.17 (4.04 to 4.30) mmol/L to a nadir of 3.32 (3.06 to 3.58) mmol/L (p ... of sodium-potassium pumps. Furthermore, terbutaline induced changes in ECG with a highly significant lengthening of the QTc interval but with an unchanged number of ventricular ectopic beats in healthy subjects....

  9. Technical note: Electrocardiogram electrode repositioning for 320-row coronary CT angiography in patients with regular and recurrent premature ventricular contractions.

    Science.gov (United States)

    Kondo, Takeshi; Matsutani, Hideyuki; Groarke, John; Takamura, Kazuhisa; Fujimoto, Shinichiro; Rybicki, Frank J; Kumamaru, Kanako K

    2014-01-01

    Arrhythmias can compromise image quality and increase radiation exposure during coronary CT angiography (CTA). However, premature ventricular contractions (PVCs) can occur in a predictable recurrent and regular pattern (ie, bigeminy, trigeminy, quadrigeminy) with post-PVC compensatory pauses. Electrocardiographic (ECG) electrode repositioning can achieve relative amplification of the R waves of PVCs compared with R waves of sinus beats. This technical note describes how simple ECG electrode repositioning, combined with an absolute-delay strategy, facilitated selective R waves of PVC ECG triggering of image acquisition in 6 patients with PVC bigeminy or quadrigeminy at the time of 320-row coronary CTA. All 6 studies were single heartbeat acquisition scans with excellent image quality and a median effective radiation dose of 2.9 mSv (interquartile range, 2.1-3.8 mSv). Standard ECG electrode positions used for 2 patients with PVC bigeminy undergoing coronary CTA were associated with an acquisition over 2 heartbeats and effective radiation doses of 6.8 and 10.3 mSv, respectively. In conclusion, ECG electrode repositioning combined with an absolute-delay strategy for regularly recurring PVCs, such as ventricular bigeminy, facilitates high image quality and lower radiation dose during coronary CTA. This simple and straightforward technique can be considered for all patients with regular and recurrent PVCs undergoing coronary CTA.

  10. QT interval prolongation after Premature Ventricular Contractions (PVCs

    Directory of Open Access Journals (Sweden)

    Mohammed Haroon Rashid

    2010-11-01

    Full Text Available Long QT syndrome (LQTS is an inherited ion channelopathy resulting in abnormal ventricular repolarization and abnormal prolongation of QT interval on the ECG. Syncope, fainting, cardiac arrest, and sudden death are common manifestations of LQTS. We present a case report that describes a patient with prolonged QT interval after extrasystoles and a family history of sudden cardiac deaths.

  11. Short-term beat-to-beat variability of the QT interval is increased and correlates with parameters of left ventricular hypertrophy in patients with hypertrophic cardiomyopathy.

    Science.gov (United States)

    Orosz, Andrea; Baczkó, István; Nagy, Viktória; Gavallér, Henriette; Csanády, Miklós; Forster, Tamás; Papp, Julius Gy; Varró, András; Lengyel, Csaba; Sepp, Róbert

    2015-09-01

    Stratification models for the prediction of sudden cardiac death (SCD) are inappropriate in patients with hypertrophic cardiomyopathy (HCM). We investigated conventional electrocardiogram (ECG) repolarization parameters and the beat-to-beat short-term QT interval variability (QT-STV), a new parameter of proarrhythmic risk, in 37 patients with HCM (21 males, average age 48 ± 15 years). Resting ECGs were recorded for 5 min and the frequency corrected QT interval (QTc), QT dispersion (QTd), beat-to-beat short-term variability of QT interval (QT-STV), and the duration of terminal part of T waves (Tpeak-Tend) were calculated. While all repolarization parameters were significantly increased in patients with HCM compared with the controls (QTc, 488 ± 61 vs. 434 ± 23 ms, p < 0.0001; QT-STV, 4.5 ± 2 vs. 3.2 ± 1 ms, p = 0.0002; Tpeak-Tend duration, 107 ± 27 vs. 91 ± 10 ms, p = 0.0015; QTd, 47 ± 17 vs. 34 ± 9 ms, p = 0.0002), QT-STV had the highest relative increase (+41%). QT-STV also showed the best correlation with indices of left ventricular (LV) hypertrophy, i.e., maximal LV wall thickness normalized for body surface area (BSA; r = 0.461, p = 0.004) or LV mass (determined by cardiac magnetic resonance imaging) normalized for BSA (r = 0.455, p = 0.015). In summary, beat-to-beat QT-STV showed the most marked increase in patients with HCM and may represent a novel marker that merits further testing for increased SCD risk in HCM.

  12. Premature Contractions

    Science.gov (United States)

    ... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Premature Contractions - PACs and PVCs Updated:Dec 15,2016 ... You felt this more-forceful beat. Types of premature contractions Premature atrial contractions (PACs) start in the ...

  13. Beating Heart Mitral Valve Replacement Surgery without Aortic Cross-Clamping via Right Thoracotomy in a Patient with Compromised Left Ventricular Functions

    Directory of Open Access Journals (Sweden)

    Ahmet Baris-Durukan

    2015-10-01

    Full Text Available Global myocardial ischemia and ischemia-reperfusion injury are potential adverse events related with cardioplegic arrest. Beating heart surgery has avoided such complications and adapted to valve surgery following successful results published on myocardial revascularization. Difficulty in weaning from cardiopulmonary bypass may be lessened by using on-pump beating heart surgery for mitral valve interventions. Here we describe a 64-year-old male patient with severe mitral regurgitation and dilated cardiomyopathy. Beating heart mitral valve replacement surgery was performed without aortic cross-clamping through a right thoracotomy approach. We believe that, particularly in patients with poor left ventricular functions, beating heart mitral valve surgery may be advantageous

  14. Lesson Three Ventricular premature complexes%第3课 室性期前收缩

    Institute of Scientific and Technical Information of China (English)

    鲁端; 顾晓燕

    2002-01-01

    @@ Ventricular premature complexes(VPCs) are among the most common arrhythmias and occur in patients with and without heart disease. Of adult males. ≥ 60 percent will exhibit VPCs during a 24 - h Holter monitoring. In patients without heart disease, VPCs have not been shown 1 to be associated with 2 any increased incidence in mortality or morbidity. VPCs may occur in up to 80 percent of patients with previous myocardial infarction, and in this setting, if frequent( > 10 per hour) and/ or complex(occurring in couplets), they have been associated with increased mortality.

  15. Effect of burden and origin sites of premature ventricular contractions on left ventricular function by 7-day Holter monitor.

    Science.gov (United States)

    Xu, Wenhua; Li, Mingfang; Chen, Minglong; Yang, Bing; Wang, Daowu; Kong, Xiangqing; Chen, Hongwu; Ju, Weizhu; Gu, Kai; Cao, Kejiang; Liu, Hailei; Jiang, Qi; Shi, Jiaojiao; Cui, Yan; Wang, Hong

    2015-11-01

    Recent studies have shown that premature ventricular contractions (PVCs) could enlarge the heart, but its risk factors are incompletely understood as a single 24-hour recording cannot reflect the true PVC burden due to day-to-day variability. Our purpose was to investigate the effect of burden and origin sites on left ventricular (LV) function in patients with PVCs by 7-day Holter electrocardiography (ECG). From May 2012 to August 2013, 112 consecutive patients with PVCs were recruited from the authors' affiliated hospital. All patients received 2-dimensional transthoracic echocardiography, 12-lead routing ECG and 7-days Holter ECG. Serum N-terminal pro-brain natriuretic peptide (NT-proBNP) levels were measured. A total of 102 participants with PVCs were included in the final analysis. Origin of PVCs from the tricuspid annulus had the highest burden and NT-proBNP level. LV papillary muscle had a higher LV ejection fraction (EF) level and a lower LV end-systolic dimension (ESD) than other PVC foci (PHolter monitor showed the true PVC burden on patients with PVCs. PVCs with a lower burden or origin from the LV papillary muscle and the fascicle were relatively benign, while PVCs with a higher burden or origin from the tricuspid annulus may lead to cardiac dysfunction.

  16. Calcium release near L-type calcium channels promotes beat-to-beat variability in ventricular myocytes from the chronic AV block dog.

    Science.gov (United States)

    Antoons, Gudrun; Johnson, Daniel M; Dries, Eef; Santiago, Demetrio J; Ozdemir, Semir; Lenaerts, Ilse; Beekman, Jet D M; Houtman, Marien J C; Sipido, Karin R; Vos, Marc A

    2015-12-01

    Beat-to-beat variability of ventricular repolarization (BVR) has been proposed as a strong predictor of Torsades de Pointes (TdP). BVR is also observed at the myocyte level, and a number of studies have shown the importance of calcium handling in influencing this parameter. The chronic AV block (CAVB) dog is a model of TdP arrhythmia in cardiac hypertrophy, and myocytes from these animals show extensive remodeling, including of Ca(2+) handling. This remodeling process also leads to increased BVR. We aimed to determine the role that (local) Ca(2+) handling plays in BVR. In isolated LV myocytes an exponential relationship was observed between BVR magnitude and action potential duration (APD) at baseline. Inhibition of Ca(2+) release from sarcoplasmic reticulum (SR) with thapsigargin resulted in a reduction of [Ca(2+)]i, and of both BVR and APD. Increasing ICaL in the presence of thapsigargin restored APD but BVR remained low. In contrast, increasing ICaL with preserved Ca(2+) release increased both APD and BVR. Inhibition of Ca(2+) release with caffeine, as with thapsigargin, reduced BVR despite maintained APD. Simultaneous inhibition of Na(+)/Ca(2+) exchange and ICaL decreased APD and BVR to similar degrees, whilst increasing diastolic Ca(2+). Buffering of Ca(2+) transients with BAPTA reduced BVR for a given APD to a greater extent than buffering with EGTA, suggesting subsarcolemmal Ca(2+) transients modulated BVR to a larger extent than the cytosolic Ca(2+) transient. In conclusion, BVR in hypertrophied dog myocytes, at any APD, is strongly dependent on SR Ca(2+) release, which may act through modulation of the l-type Ca(2+) current in a subsarcolemmal microdomain.

  17. Frequency, origin, and outcome of ventricular premature complexes in patients with or without heart diseases.

    Science.gov (United States)

    Lee, Ying-Hsiang; Zhong, Li; Roger, Veronique L; Asirvatham, Samuel J; Shen, Win-Kuang; Slusser, Joshua P; Hodge, David O; Cha, Yong-Mei

    2014-11-01

    The objective of the present study was to investigate the relation of ventricular premature complex (VPC) burden, origin, and electrocardiographic characteristics with left ventricular function and survival. Of 1,589 study patients, 388 (25%), 610 (38%), and 591 (37%) had low (10,000/24 hours) VPC burden, respectively. Twenty-three percent of study patients had a left ventricular (LV) ejection fraction <50% (8% in low-, 20% in moderate-, and 36% in high-VPC-burden groups, p <0.001). High VPC burden was associated with lower LV ejection fraction in the presence (r = -0.17, p <0.001) and absence (r = -0.20, p <0.001) of heart diseases. The Kaplan-Meier survival estimates showed a significant difference among the 3 VPC burden groups (p = 0.046). The survival rates were significantly lower for patients with a VPC coupling interval of ≥480 ms than those with a VPC coupling interval of <480 ms (p = 0.002) and lower for those with a VPC QRS duration of ≥150 ms than those with a VPC QRS duration of <150 ms (p <0.001). In conclusion, high VPC burden is detrimental to LV systolic function. Broader VPC QRS duration and longer VPC coupling interval adversely impact on long-term survival.

  18. Single-Beat Noninvasive Imaging of Ventricular Endocardial and Epicardial Activation in Patients Undergoing CRT

    OpenAIRE

    Thomas Berger; Bernhard Pfeifer; Friedrich F Hanser; Florian Hintringer; Gerald Fischer; Michael Netzer; Thomas Trieb; Markus Stuehlinger; Wolfgang Dichtl; Christian Baumgartner; Otmar Pachinger; Michael Seger

    2011-01-01

    BACKGROUND: Little is known about the effect of cardiac resynchronization therapy (CRT) on endo- and epicardial ventricular activation. Noninvasive imaging of cardiac electrophysiology (NICE) is a novel imaging tool for visualization of both epi- and endocardial ventricular electrical activation. METHODOLOGY/PRINCIPAL FINDINGS: NICE was performed in ten patients with congestive heart failure (CHF) undergoing CRT and in ten patients without structural heart disease (control group). NICE is a f...

  19. Predicting utility of exercise tests based on history/holter in patients with premature ventricular contractions.

    Science.gov (United States)

    Robinson, Brad; Xie, Li; Temple, Joel; Octavio, Jenna; Srayyih, Maytham; Thacker, Deepika; Kharouf, Rami; Davies, Ryan; Gidding, Samuel S

    2015-01-01

    Premature ventricular contractions (PVCs) are considered benign in patients with structurally normal hearts, particularly if they suppress with exercise. Catecholaminergic polymorphic ventricular tachycardia (CPVT) requires exercise testing to unmask the malignant phenotype. We studied risk factors and Holter monitor variables to help predict the necessity of exercise testing in patients with PVCs. We retrospectively reviewed 81 patients with PVCs that suppressed at peak exercise and structurally normal hearts referred to the exercise laboratory in 2011. We reviewed 11 patients from 2003 to 2012 whose PVCs were augmented at peak exercise (mean age 13 ± 4 years; 52 % male, 180 exercise studies). We recorded clinical risk factors and comorbidities (family history of arrhythmia or sudden unexpected death [SUD], presence of syncope) and Holter testing parameters. Family history of VT or SUD (P = 0.011) and presence of VT on Holter (P = 0.011) were significant in predicting failure of PVCs to suppress at peak heart rate on exercise testing. Syncope was not statistically significant in predicting suppression (P = 0.18); however, CPVT was diagnosed in four patients with syncope during exercise. Quantity of PVCs, Lown grade, couplets on Holter, monomorphism, and PVC elimination at peak heart rate on Holter were not predictors of PVC suppression on exercise testing. Patients with syncope during exercise, family history of arrhythmia or SUD, or a Holter monitor showing VT warrant exercise testing to assess for CPVT.

  20. Predictive value of beat-to-beat QT variability index across the continuum of left ventricular dysfunction: competing risks of noncardiac or cardiovascular death and sudden or nonsudden cardiac death.

    Science.gov (United States)

    Tereshchenko, Larisa G; Cygankiewicz, Iwona; McNitt, Scott; Vazquez, Rafael; Bayes-Genis, Antoni; Han, Lichy; Sur, Sanjoli; Couderc, Jean-Philippe; Berger, Ronald D; de Luna, Antoni Bayes; Zareba, Wojciech

    2012-08-01

    The goal of the present study was to determine the predictive value of beat-to-beat QT variability in heart failure patients across the continuum of left ventricular dysfunction. Beat-to-beat QT variability index (QTVI), log-transformed heart rate variance, normalized QT variance, and coherence between heart rate variability and QT variability have been measured at rest during sinus rhythm in 533 participants of the Muerte Subita en Insuficiencia Cardiaca heart failure study (mean age, 63.1±11.7; men, 70.6%; left ventricular ejection fraction >35% in 254 [48%]) and in 181 healthy participants from the Intercity Digital Electrocardiogram Alliance database. During a median of 3.7 years of follow-up, 116 patients died, 52 from sudden cardiac death (SCD). In multivariate competing risk analyses, the highest QTVI quartile was associated with cardiovascular death (subhazard ratio, 1.67 [95% CI, 1.14-2.47]; P=0.009) and, in particular, with non-SCD (subhazard ratio, 2.91 [1.69-5.01]; P<0.001). Elevated QTVI separated 97.5% of healthy individuals from subjects at risk for cardiovascular (subhazard ratio, 1.57 [1.04-2.35]; P=0.031) and non-SCD in multivariate competing risk model (subhazard ratio, 2.58 [1.13-3.78]; P=0.001). No interaction between QTVI and left ventricular ejection fraction was found. QTVI predicted neither noncardiac death (P=0.546) nor SCD (P=0.945). Decreased heart rate variability rather than increased QT variability was the reason for increased QTVI in the present study. Increased QTVI because of depressed heart rate variability predicts cardiovascular mortality and non-SCD but neither SCD nor extracardiac mortality in heart failure across the continuum of left ventricular dysfunction. Abnormally augmented QTVI separates 97.5% of healthy individuals from heart failure patients at risk.

  1. Relation of ventricular premature complexes to heart failure (from the Atherosclerosis Risk In Communities [ARIC] Study).

    Science.gov (United States)

    Agarwal, Sunil K; Simpson, Ross J; Rautaharju, Pentti; Alonso, Alvaro; Shahar, Eyal; Massing, Mark; Saba, Samir; Heiss, Gerardo

    2012-01-01

    Analogous to rapid ventricular pacing, frequent ventricular premature complexes (VPCs) can predispose over time to cardiomyopathy and subsequent heart failure (HF). We examined the association of frequent VPCs with HF incidence in a population-based cohort, free of HF and coronary heart disease at baseline. At study baseline (1987 to 1989), ≥1 VPC on a 2-minute rhythm electrocardiographic strip was seen in 5.5% (739 of 13,486) of the middle-age (45 to 64 years old at baseline) white and black, men and women of the Atherosclerosis Risk In Communities cohort. Incident HF was defined as the first appearance of International Classification of Diseases code 428.x in the hospital discharge record or death certificate through 2005. During an average follow-up of 15.6 years, incident HF was seen in 10% the participants (19.4% of those with VPCs vs 9.4% of those without). The age-, race-, and gender-adjusted hazard ratio of HF for VPCs was 1.89 (95% confidence interval 1.59 to 2.24). After multivariable adjustment for potential confounders, the hazard ratio of HF for those with any VPC versus no VPC was 1.63 (95% confidence interval 1.36 to 1.96). After additional adjustment for incident coronary heart disease as a time-varying covariate, the hazard ratio was 1.71 (95% confidence interval 1.42 to 2.08). Those with a greater frequency of VPCs or complex VPCs had similar rates of HF compared to those with a single VPC and all had rates greater than those with no VPC. In conclusion, in this large population-based cohort, the presence of VPCs was associated with incident HF, independent of incident coronary heart disease.

  2. Cellular graded responses and ventricular vulnerability to reentry by a premature stimulus in isolated canine ventricle.

    Science.gov (United States)

    Gotoh, M; Uchida, T; Mandel, W J; Fishbein, M C; Chen, P S; Karagueuzian, H S

    1997-04-15

    The cellular mechanism by which a point strong premature stimulus (S2) induces reentry is unknown. We hypothesized that cellular graded responses induced by an S2 mediate and control tissue vulnerability to reentry. Reentry is induced in normal canine ventricular epicardial slices (30x38x2 mm, n=30) by an S2 at intervals shorter than the effective refractory period. The S1 is applied at the edge and the S2 at the center of the tissue. The line connecting the S1-S2 sites is parallel to the long axis of the fiber orientation. Isochronal activation maps were constructed with 56 to 480 bipolar electrodes, and the activation pattern was visualized dynamically. Reentry induced by an S2 is mediated by the graded responses as follows: The induced graded responses propagate with decrement toward recovered cells. When the amplitude of the propagated depolarizing graded responses reaches threshold relative to the recovering cells, an action potential is initiated along the fiber 2 to 3 mm away from the cathode of the S2. The distally initiated activation wave front blocks near the S2 site because the same S2-induced graded response prolongs the refractory period. The "broken" wave front then circulates around both sides of the block and reenters when the site of block recovers its excitability, completing the first figure-eight reentry cycle. Reentry cannot be induced when the S2 strength is >72+/-21 mA (upper limit of vulnerability) because these strong S2-induced graded responses convert the unidirectional block to bidirectional block by excess prolongation of the refractoriness. We conclude that the magnitude and the propagation of S2-induced cellular graded responses mediate and control vulnerability to reentry in the ventricular epicardium.

  3. Study of left ventricular systolic synchrony and sequence in patients with premature ventricular complexes from right ventricular outflow tract%右心室流出道起源室性期前收缩患者左心室收缩同步性及时序的研究

    Institute of Scientific and Technical Information of China (English)

    姚静; 许迪; 陆凤翔; 雍永宏; 庄燕; 季玲; 曹克将

    2010-01-01

    目的 分析正常人及右室流出道(right ventricular outflow tract,RVOT)起源室性期前收缩(premature ventricular complexes,PVCs)患者收缩期应变达峰时间,探讨RVOT起源PVCs患者心肌收缩同步性及时序规律.方法 应用斑点追踪成像(speckle tracking imaging,STI)技术测量30例RVOT起源PVCs患者在窦性心搏、室性心搏时及30例正常人纵向(TsL)、环周(TsC)、径向(TsR)收缩期应变达峰时间,分别计算标准差,并分析室性心搏时各方向应变达峰时间时序分布规律.结果 与正常对照组比较,RVOT起源PVCs患者在室性心搏时TsL、TsC、TsR标准差均增大,窦性心搏时TsC、TsR标准差增大.室性心搏时,TsL、TsR从心尖至基底的不同层面间差异显著;TsL、TsC在不同室壁间差异显著.结论 RVOT起源PVCs患者在窦性心搏及室性心搏时均存在失同步状态,其中室性心搏时各方向应变达峰时间时序分布存在规律.%Objective To evaluate left ventricular(LV) systolic synchrony and sequence in patients with premature ventricular complexes(PVCs) from right ventricular outflow tract (RVOT).Methods Thirty patients with frequent isolated PVCs from RVOT and 30 healthy subjects as control were included.Speckle tracking imaging (STI) was performed to assess the time-to-peak segmental systolic strain in longit udinal(TsL), circumferential (TsC) and radial (TsR) direction.The standard deviation (SD) of TsL,TsC and TsR of 18 LV segments were calculated respectively.All values of patients with PVCs were recorded during sinus beats(PVC-S) and PVC beats(PVC-V) respectively.LV systolic sequence in PVC-V was analyzed.Results Significant differences were observed in the SD values between the PVC-V and control subjects in three directions,as well as between the PVC-S and control subjects in circumferential and radial direction.In PVC-V significance difference was seen in TsL and TsR from apical to basal level,as well as in TsL and TsC in different

  4. Myocardial contrast echocardiography (MCE) with triggered ultrasound does not cause premature ventricular complexes: evidence from PB127 MCE studies.

    Science.gov (United States)

    Raisinghani, Ajit; Wei, Kevin S; Crouse, Linda; Villanueva, Floredeliza; Feigenbaum, Harvey; Schiller, Nelson B; Weiss, James; Naqvi, Tasneem Z; Siegel, Robert; Monaghan, Mark; Goldman, Jonathan H; Demaria, Anthony

    2003-10-01

    Previous studies suggest that myocardial contrast echocardiography using high mechanical index triggered ultrasound can be associated with increased frequency of the premature ventricular complex (PVC). However, this association has not been systematically examined. PB127 (Point Biomedical Corp, San Carlos, Calif) is a novel microsphere designed for evaluation of myocardial perfusion with ultrasound. PB127 myocardial contrast echocardiography was performed with triggered harmonic power Doppler in early/mid diastole (mechanical index premature ventricular complex frequency at baseline, during, and after infusion of PB127 (dose premature ventricular complex were determined. PVC frequency did not increase with PB127 infusion in either cohort (P =.572, P =.263). Proportion of triggered intervals after QRS associated with PVC was similar to proportion of untriggered intervals in cohort A (P >.999) and was lower than untriggered intervals (P =.001) in B, suggesting that triggers do not cause PVC. PB127 does not cause increase PVC frequency during or after imaging with triggered ultrasound at mechanical index of 1.

  5. Early feasibility testing and engineering development of a sutureless beating heart connector for left ventricular assist devices.

    Science.gov (United States)

    Koenig, Steven C; Jimenez, Jorge H; West, Seth D; Sobieski, Michael A; Choi, Young; Monreal, Gretel; Giridharan, Guruprasad A; Soucy, Kevin G; Slaughter, Mark S

    2014-01-01

    APK Advanced Medical Technologies (Atlanta, GA) is developing a sutureless beating heart (SBH) left ventricular assist device (LVAD) connector system consisting of anchoring titanium coil, titanium cannula with integrated silicone hemostatic valve, coring and delivery tool, and LVAD locking mechanism to facilitate LVAD inflow surgical procedures. Feasibility testing was completed in human cadavers (n = 4) under simulated normal and hypertensive conditions using saline to observe seal quality in degraded human tissue and assess anatomic fit; acutely in ischemic heart failure bovine model (n = 2) to investigate short-term performance and ease of use; and chronically for 30 days in healthy calves (n = 2) implanted with HeartWare HVAD to evaluate performance and biocompatibility. Complete hemostasis was achieved in human cadavers and animals at LV pressures up to 170 mm Hg. In animals, off-pump (no cardiopulmonary bypass) anchoring of the connector was accomplished in less than 1 minute with no residual bleeding after full delivery and locking of the LVAD; and implant of connector and LVAD were successfully completed in under 10 minutes with total procedure blood loss less than 100 ml. In chronic animals before necropsy, no signs of leakage or disruption at the attachment site were observed at systolic LV pressures >200 mm Hg.

  6. The effect of the physical activity on polymorphic premature ventricular complexes in chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Márcio G. Kiuchi

    2017-06-01

    Full Text Available Background: Polymorphic premature ventricular complexes (PVCs are very common, appearing most frequently in patients with hypertension, obesity, sleep apnea, and structural heart disease. Sympathetic hyperactivity plays a critical role in the development, maintenance, and aggravation of ventricular arrhythmias. Endurance exercise training clearly lowers sympathetic activity in sympatho-excitatory disease states and may be tolerated by patients with chronic kidney disease (CKD. Methods: We assessed 40 CKD patients with hypertension with polymorphic PVCs. Patients underwent a complete medical history and physical examination. We evaluated the effectiveness of β blocker only or β blocker + exercise during 12 months of follow-up regarding the changes of the numbers of PVCs and mean heart rate (HR by 24-hour-Holter. Results: We observed in the β blocker group a significant decrease in the number of polymorphic PVCs from baseline 36,515 ± 3,518 to 3, 6, 9 and 12 months of follow-up, 28,314 ± 2,938, 23,709 ± 1,846, 22,564 ± 1,673, and 22,725 ± 1,415, respectively (P < 0.001. In the β blocker + exercise group a significant decrease in the number of polymorphic PVCs also occurred from baseline 36,091 ± 3,327 to 3, 6, 9 and 12 months of follow-up, 29,252 ± 3,211, 20,948 ± 2,386, 14,238 ± 3,338, and 6,225 ± 2,319, respectively (P < 0.001. Comparisons between the two groups at the same time point showed differences from the sixth month onwards: the 6th (Δ = −2,761, P = 0.045, 9th (Δ = −8,325, P < 0.001 and 12th (Δ = −16,500, P < 0.001 months. There was an improvement during the 12 months of follow-up vs. baseline, after the β blocker or β blocker + exercise in mean 24-hour HR Holter monitoring, creatinine values, eGFR, and ACR. Conclusion: Polymorphic PVCs may be modifiable by physical activity in CKD patients with hypertension without structural heart disease.

  7. Predictive Value of Beat-to-Beat QT Variability Index across the Continuum of Left Ventricular Dysfunction: Competing Risks of Non-cardiac or Cardiovascular Death, and Sudden or Non-Sudden Cardiac Death

    Science.gov (United States)

    Tereshchenko, Larisa G.; Cygankiewicz, Iwona; McNitt, Scott; Vazquez, Rafael; Bayes-Genis, Antoni; Han, Lichy; Sur, Sanjoli; Couderc, Jean-Philippe; Berger, Ronald D.; de Luna, Antoni Bayes; Zareba, Wojciech

    2012-01-01

    Background The goal of this study was to determine the predictive value of beat-to-beat QT variability in heart failure (HF) patients across the continuum of left ventricular dysfunction. Methods and Results Beat-to-beat QT variability index (QTVI), heart rate variance (LogHRV), normalized QT variance (QTVN), and coherence between heart rate variability and QT variability have been measured at rest during sinus rhythm in 533 participants of the Muerte Subita en Insuficiencia Cardiaca (MUSIC) HF study (mean age 63.1±11.7; males 70.6%; LVEF >35% in 254 [48%]) and in 181 healthy participants from the Intercity Digital Electrocardiogram Alliance (IDEAL) database. During a median of 3.7 years of follow-up, 116 patients died, 52 from sudden cardiac death (SCD). In multivariate competing risk analyses, the highest QTVI quartile was associated with cardiovascular death [hazard ratio (HR) 1.67(95%CI 1.14-2.47), P=0.009] and in particular with non-sudden cardiac death [HR 2.91(1.69-5.01), P<0.001]. Elevated QTVI separated 97.5% of healthy individuals from subjects at risk for cardiovascular [HR 1.57(1.04-2.35), P=0.031], and non-sudden cardiac death in multivariate competing risk model [HR 2.58(1.13-3.78), P=0.001]. No interaction between QTVI and LVEF was found. QTVI predicted neither non-cardiac death (P=0.546) nor SCD (P=0.945). Decreased heart rate variability (HRV) rather than increased QT variability was the reason for increased QTVI in this study. Conclusions Increased QTVI due to depressed HRV predicts cardiovascular mortality and non-sudden cardiac death, but neither SCD nor excracardiac mortality in HF across the continuum of left ventricular dysfunction. Abnormally augmented QTVI separates 97.5% of healthy individuals from HF patients at risk. PMID:22730411

  8. Safety and efficacy in ablation of premature ventricular contraction: data from the German ablation registry.

    Science.gov (United States)

    Fichtner, S; Senges, J; Hochadel, M; Tilz, R; Willems, S; Eckardt, L; Deneke, T; Lewalter, T; Dorwarth, U; Reithmann, C; Brachmann, J; Steinbeck, G; Kääb, S

    2017-01-01

    Patients with frequent premature ventricular contractions (PVCs) are often highly symptomatic with significantly reduced quality-of-life. We evaluated the outcome and success of PVC ablation in patients in the German Ablation Registry. The German Ablation Registry is a nationwide prospective multicenter database of patients who underwent an ablation procedure, initiated by the "Stiftung Institut für Herzinfarktforschung" (IHF), Ludwigshafen, Germany. Data were acquired from March 2007 to May 2011. Patients underwent PVC ablation in the enrolling ablation centers. A total of 408 patients (age 53.5 ± 15 years, 55 % female) undergoing ablation for PVCs were included. 32 % of patients showed a co-existing structural heart disease. Acute ablation success of the procedure was 82 % in the overall patient group. In patients without structural heart disease, acute success was significantly higher compared with patients with structural heart disease (86 vs. 74 %, p = 0.002). All patients were discharged alive after a median of 3 days. No patient suffered an acute myocardial infarction, stroke, or major bleeding. After 12 months' follow-up, 99 % of patients were still alive showing a significant different mortality between patients with structural heart disease compared with those without (2.3 vs. 0 %, p = 0.012). In addition, 76 % of patients showed significantly improved symptoms after 12 months of follow-up. Based on the data from this registry, ablation of PVCs is a safe and efficient procedure with an excellent outcome and improved symptoms after 12 months.

  9. A novel approach for the diagnosis of ventricular tachycardia based on phase space reconstruction of ECG

    CERN Document Server

    Koulaouzidis, George; Cappiello, Grazia; Mazomenos, Evangelos B; Maharatna, Koushik; Morgan, John

    2014-01-01

    Ventricular arrhythmias comprise a group of disorders which manifest clinically in a variety of ways from ventricular premature beats (VPB) and no sustained ventricular tachycardia (in healthy subjects) to sudden cardiac death due to ventricular tachyarrhythmia in patients with and/or without structural heart disease. Ventricular fibrillation (VF) and ventricular tachycardia (VT) are the most common electrical mechanisms for cardiac arrest. Accurate and automatic recognition of these arrhythmias from electrocardiography (ECG) is a crucial task for medical professionals. The purpose of this research is to develop a new index for the differential diagnosis of normal sinus rhythm (SR) and ventricular arrhythmias, based on phase space reconstruction (PSR).

  10. 频发室性期前收缩所致心肌病患者心功能变化及治疗分析%Heart Function Changes of Frequent Premature Ventricular Contractions-induced Cardiomyopathy and Its Treatment

    Institute of Scientific and Technical Information of China (English)

    苏广玉

    2015-01-01

    目的:分析频发室性期前收缩所致心肌病( PVCs-ICM)患者心功能变化及治疗,提高临床医生对PVCs-ICM的诊治水平。方法选取2012—2013年在梅州市人民医院心内科行射频消融术( RFCA)治疗的频发室性期前收缩患者128例,根据PVCs-ICM发生情况分为观察组57例(并发PVCs-ICM)和对照组71例(未并发PVCs-ICM)。两组患者均于RFCA治疗后随访6~9个月,比较两组患者RFCA治疗效果;观察两组患者治疗前左室射血分数( LVEF)、左室舒张末期内径( LVEDD)、室性期前收缩负荷量、QRS 波宽度及观察组患者治疗6个月后 LVEF、LVEDD、室性期前收缩负荷量改善情况。结果观察组患者RFCA治疗有效率为84.2%,对照组为84.5%,差异无统计学意义(P﹥0.05)。观察组患者治疗前LVEF低于对照组,LVEDD、室性期前收缩负荷量、QRS波宽度高于对照组(P﹤0.05)。观察组患者治疗6个月后LVEF高于治疗前,LVEDD、室性期前收缩负荷量低于治疗前(P﹤0.05)。结论 PVCs-ICM患者心功能明显降低,室性期前收缩负荷量明显增高,QRS波明显增宽,RFCA治疗可有效改善PVCs%Objective To analyze heart function changes of frequent premature ventricular contractions -induced cardiomyopathy(PVCs - ICM)and its treatment. Methods From 2012 to 2013,a total of 128 patients with frequent premature ventricular contractions were selected in the Department of Cardiology,People's Hospital of Meizhou,all of them were given radiofrequency catheter ablation( RFCA),and they were divided into observation group( complicated with PVCs-ICM, n=57)and control group(uncomplicated with PVCs-ICM,n=71)according to the incidence of PVCs-ICM. Patients of both groups were followed-up for 6 to 9 months,and the therapeutic effect was compared. LVEF,LVEDD,load capacity of premature ventricular beats and QRS complex width were compared between the two groups before treatment

  11. Myocardial performance is reduced immediately prior to ventricular ectopy

    DEFF Research Database (Denmark)

    Bloch Thomsen, Poul Erik; Hansen, Thomas Fritz; Jons, Christian;

    2012-01-01

    of impulse conduction would also lead to changes in the contractile performance of sinus beats preceding ventricular ectopy using Tissue Doppler echocardiography. Methods: Twenty-three consecutive patients with VPBs were examined in the apical 4-chamber view with a frame rate of 150 Hz (GE VIVID VII). Eleven......Background: We recently demonstrated local voltage potentials indicating conduction impairment and block in the sinus beats preceding ventricular premature beats (VPBs) originating in the ventricular outflow tracts. Objective: The purpose of this study was to test the hypothesis that impairment...... patients had no structural heart disease, 5 had dilated cardiomyopathy, 4 had ischemic heart disease, 2 had arrhythmogenic right ventricular dysplasia, and 1 had aortic stenosis. The ectopy originated in the ventricular outflow tracts in 15 patients and in the left ventricle 8. Eleven of the patients...

  12. A Multidisciplinary Approach to Unplanned Conversion from Off-Pump to On-Pump Beating Heart Coronary Artery Revascularization in Patients with Compromised Left Ventricular Function

    Directory of Open Access Journals (Sweden)

    Georgia Tsaousi

    2014-01-01

    Full Text Available Aim. To comparably assess the perioperative risk factors that differentiate off-pump coronary artery bypass (OPCAB grafting cases from those sustaining unplanned conversion to on-pump beating heart (ONCAB/BH approach, in patients with left ventricular ejection fraction (LVEF 2 days (P=0.007. Conclusions. Patients with LVEF < 40% undergoing ONCAB/BH are subjected to more preoperative comorbidities and implicated ICU stay than their OPCAB counterparts, which influences adversely short-term morbidity, while operative mortality remains unaffected.

  13. The Efficacy and Safety of Wenxin Keli in Patients with Frequent Premature Ventricular Contractions: A Randomized, Double-blind, Placebo-controlled, Parallel-group, Multicenter Trial

    Institute of Scientific and Technical Information of China (English)

    Wei Hua; Run-Lin Gao; Bu-Chang Zhao; Jing Wang; Xu-Hua Chen; Chi Cai; Shu Zhang

    2015-01-01

    Background:Premature ventricular contractions (PVCs) are common in the general population,and frequent PVCs may result in the poor quality of life or even the damage of cardiac function.We examined the efficacy and safety of a traditional Chinese medicine Wenxin Keli for the treatment of frequent PVCs among a relatively large Chinese cohort.Methods:We performed a randomized,double-blind,placebo-controlled,parallel-group,multicenter trial.A total of 1200 eligible participants were randomly assigned in a ratio of 1:1 to receive Wenxin Keli or the placebo for 4 weeks.The primary and secondary endpoint was the change of PVC numbers and PVC-related symptoms after a 4-week treatment compared with baseline,respectively.In addition,vital signs,laboratory values,and electrocardiographic parameters were assessed in a safety analysis.Results:At the initial evaluation,no significant differences in the baseline characteristics were observed between the Wenxin Keli group and the placebo group.A smaller number of PVCs was observed after the 4-week treatment than at baseline,in both the Wenxin Keli group (5686 ± 5940 vs.15,138 ± 7597 beats/d,P < 0.001) and the placebo group (10,592 ± 8009 vs.14,529 ± 5929 beats/d,P < 0.001);moreover,the Wenxin Keli group demonstrated a significantly greater reduction in the frequency of PVCs than the placebo group (P < 0.001).In a full analysis set,patients in the Wenxin Keli group exhibited significantly higher total effective responses in the reduction of PVCs compared to those in the placebo group (83.8% vs.43.5%,P < 0.001).The per-protocol analysis yielded similar results (83.0% vs.39.3%,P < 0.001).Treatment with Wenxin Keli also demonstrated superior performance compared to the placebo with respect to PVC-related symptoms.No severe adverse effects attributable to Wenxin Keli were reported.Conclusions:Wenxin Keli treatment effectively reduced the overall number of PVCs and alleviated PVC-related symptoms in patients

  14. Clinical Study on the Change of Plasma BNP in Patients with Idiopathic Frequent Ventricular Premature Contraction after Radiofrequency Catheter Ablation%特发性频发室性早搏患者经导管射频消融术后血浆BNP水平变化的临床研究

    Institute of Scientific and Technical Information of China (English)

    刘福强; 李岩; 谢勇; 赵冬华; 萧钟波; 彭健

    2011-01-01

    [Objective]To explore the change of plasma Btype natriuretic peptide(BNP) in idiopathic frequent ventricular premature contraction patients with normal cardiac function after radiofrequency catheter ablation(RFCA) and its significance. [Methods]Thirty-three patients with frequent ventricular premature contraction receiving RFCA successfully were selected as ventricular premature contraction group with a total of 16,391.03±10,873. 0l beats per day. Other 53 healthy subjects were selected as the control group. Heart color echocardiography, dynamic electrocardiogram and plasma BNP in two groups were examined. The reexamination of ventricular premature contraction group was taken 3 months after operation. Left ventricular ejection fraction(LVEF), left ventricular end-diastolic dimension(LVEDd) and plasma BNP in were compared between two groups and before and after operation. [Results]Plasma BNP in control group was significantly lower than that in ventricular premature contraction group before operation( P <0. 0l). Compared with before operation, plasma BNP in ventricular premature contraction group after obviously decreased after operation( P <0. 0l). There was no significant difference in plasma BNP between control group and ventricular prematurecontraction group after operation( P >0. 05). There was no obvious difference in LVEF and LVEDd among all groups( P >0. 05). [Conclusion]Plasma BNP in idiopathic frequent ventricular premature contraction patients with normal cardiac function is increased. RFCA can effectively treat the ventricular premature contraction and decrease the plasma BNP of patients. When the cardiac structure examined by heart color echocardiography has no obvious change, plasma BNP can be used to evaluate the severity, development and prognosis of patients with ventricular premature contraction.%[目的]探讨心功能正常的特发性频发室性早搏(PVC)患者经射频消融术(RFCA)后血浆脑钠肽(BNP

  15. Cardiac Arrest due to Recurrent Ventricular Fibrillation Triggered by Unifocal Ventricular Premature Complexes in a Silent Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Dong Hyun Lee

    2014-11-01

    Suspecting idiopathic VF, emergency radiofrequency catheter ablation was planned for the VPCs. However, when coronary angiography was performed to exclude silent ischemia, the results showed a total occlusion of the right coronary artery posterolateral branch, which is thought to supply the left ventricular inferior and septal wall. After successful reperfusion, VF episodes and the triggering VPCs disappeared. We are documenting this case to emphasize the potential for silent myocardial infarction to cause out-of-hospital sudden cardiac arrest even in a patient without any symptom or sign of acute coronary syndrome.

  16. Radiofrequency ablation of premature ventricular contractions with ECG like originating from the right ventricular outflow tract guided by CARTO%CARTO电解剖标测指导右室流出道图形室性早搏的射频消融治疗

    Institute of Scientific and Technical Information of China (English)

    纪元; 丁志坚; 蒋建光; 刘志平; 周学军

    2011-01-01

    AIM: To assess the clinical efficacy of electro-anatomically guided mapping and radiofrequency ablation under CARTO system for frequent premature ventricularcontraction. METHODS: The CARTO electro-anatomical mapping system displays real time three dimensional chamber structure with electrical information related to signal mplitude and activation time. 22 patients with Drug refractory and frequent premature ventricular contractions were ablated under CARTO system. By preoperative and postoperative SF-36, the generally health, physical function and conduct scoring among patients after procedure were observed. RESULTS:Frequent premature ventricular contractions were successfully ablated in all 22 patients with mean 2. 6± 1.2 radiofrequency applications under CARTO system. 19/22 frequent premature ventricular contractions occurred in right ventricle, and 3/22 in left ventricule. After ab-lation, the premature ventricular contractions declined from (17932 + 3816) beats/24 h to (13 ±6) beats/24 h, and patients symptoms almost disappeared. No recurrent case was found during following observation. The patient overall quality of life improved markedly. CONCLUSION: The CARTO electro-anatomical mapping system, referred to the electro physiologic data, may be applied in guiding the radiofrequency ablation of drug-refractory and frequent premature ventricular contractions in those patients who have no organic heart disease for its highly efficacy, safety and accurate orientation, and could significantly improve patient quality of life.%目的:评价CARTO电解剖标测系统指导消融治疗右室流出道图形室性早搏的临床应用价值.方法:应用CART(电解剖标测系统在相关心室进行标测,构建心室三维电激动图并指导消融,治疗22例药物治疗无效、非器质性心脏病患者频发右室流出道图形室性早搏(常规心电图QRS波呈完全性左束支阻滞图形,Ⅱ、Ⅲ、avF呈高幅R形态)(右心室室性早搏19

  17. Experimentally-Based Computational Investigation into Beat-To-Beat Variability in Ventricular Repolarization and Its Response to Ionic Current Inhibition.

    Directory of Open Access Journals (Sweden)

    E Pueyo

    Full Text Available Beat-to-beat variability in repolarization (BVR has been proposed as an arrhythmic risk marker for disease and pharmacological action. The mechanisms are unclear but BVR is thought to be a cell level manifestation of ion channel stochasticity, modulated by cell-to-cell differences in ionic conductances. In this study, we describe the construction of an experimentally-calibrated set of stochastic cardiac cell models that captures both BVR and cell-to-cell differences in BVR displayed in isolated canine action potential measurements using pharmacological agents. Simulated and experimental ranges of BVR are compared in control and under pharmacological inhibition, and the key ionic currents determining BVR under physiological and pharmacological conditions are identified. Results show that the 4-aminopyridine-sensitive transient outward potassium current, Ito1, is a fundamental driver of BVR in control and upon complete inhibition of the slow delayed rectifier potassium current, IKs. In contrast, IKs and the L-type calcium current, ICaL, become the major contributors to BVR upon inhibition of the fast delayed rectifier potassium current, IKr. This highlights both IKs and Ito1 as key contributors to repolarization reserve. Partial correlation analysis identifies the distribution of Ito1 channel numbers as an important independent determinant of the magnitude of BVR and drug-induced change in BVR in control and under pharmacological inhibition of ionic currents. Distributions in the number of IKs and ICaL channels only become independent determinants of the magnitude of BVR upon complete inhibition of IKr. These findings provide quantitative insights into the ionic causes of BVR as a marker for repolarization reserve, both under control condition and pharmacological inhibition.

  18. An efficient method for ectopic beats cancellation based on radial basis function.

    Science.gov (United States)

    Mateo, Jorge; Torres, Ana; Rieta, José J

    2011-01-01

    The analysis of the surface Electrocardiogram (ECG) is the most extended noninvasive technique in cardiological diagnosis. In order to properly use the ECG, we need to cancel out ectopic beats. These beats may occur in both normal subjects and patients with heart disease, and their presence represents an important source of error which must be handled before any other analysis. This paper presents a method for electrocardiogram ectopic beat cancellation based on Radial Basis Function Neural Network (RBFNN). A train-able neural network ensemble approach to develop customized electrocardiogram beat classifier in an effort to further improve the performance of ECG processing and to offer individualized health care is presented. Six types of beats including: Normal Beats (NB); Premature Ventricular Contractions (PVC); Left Bundle Branch Blocks (LBBB); Right Bundle Branch Blocks (RBBB); Paced Beats (PB) and Ectopic Beats (EB) are obtained from the MIT-BIH arrhythmia database. Four morphological features are extracted from each beat after the preprocessing of the selected records. Average Results for the RBFNN based method provided an ectopic beat reduction (EBR) of (mean ± std) EBR = 7, 23 ± 2.18 in contrast to traditional compared methods that, for the best case, yielded EBR = 4.05 ± 2.13. The results prove that RBFNN based methods are able to obtain a very accurate reduction of ectopic beats together with low distortion of the QRST complex.

  19. Symbolic transfer entropy-based premature signal analysis

    Institute of Scientific and Technical Information of China (English)

    Wang Jun; Yu Zheng-Feng

    2012-01-01

    In this paper,we use symbolic transfer entropy to study the coupling strength between premature signals.Numerical experiments show that three types of signal couplings are in the same direction.Among them,normal signal coupling is the strongest,followed by that of premature ventricular contractions,and that of atrial premature beats is the weakest.The T test shows that the entropies of the three signals are distinct.Symbolic transfer entropy requires less data,can distinguish the three types of signals and has very good computational efficiency.

  20. REPEATED TREATMENTS WITH DOXORUBICIN CAUSES ELECTROCARDIOGRAM (ECG) CHANGES AND INCREASED VENTRICULAR PREMATURE BEATS IN WISTAR-KYOTO (WKY) RATS

    Science.gov (United States)

    Doxorubicin (DOX) is a widely used anthracycline anti-neoplastic drug used to treat tumors. However it has been implicated in irreversible cardiac toxicity via the generation of a proxidant semiquinone free radical, which often results in cardiomyopathy and changes in the ECG. Ac...

  1. REPEATED TREATMENTS WITH DOXORUBICIN CAUSES ELECTROCARDIOGRAM (ECG) CHANGES AND INCREASED VENTRICULAR PREMATURE BEATS IN WISTAR-KYOTO (WKY) RATS

    Science.gov (United States)

    Doxorubicin (DOX) is a widely used anthracycline anti-neoplastic drug used to treat tumors. However it has been implicated in irreversible cardiac toxicity via the generation of a proxidant semiquinone free radical, which often results in cardiomyopathy and changes in the ECG. Ac...

  2. An Experimental Model Using Cultured Cardiac Myocytes for a Study of the Generation of Premature Ventricular Contractions Under Ultrasound Exposure

    Science.gov (United States)

    Kudo, Nobuki; Yamamoto, Masaya

    2011-09-01

    It is known that use of a contrast agents in echocardiography increases the probability of generation of premature ventricular contractions (PVCs). As a basic study to elucidate the mechanisms and to reduce adverse effects, the generation of PVCs was investigated using cultured cardiac myocytes instead of the intact heart in vivo. Cardiac myocytes were isolated from neonatal rats and cultured on a cover slip. The myocyte sample was exposed to pulsed ultrasound with microbubbles adjacent to the myocytes, and generation of PVCs was examined with ultrasound exposure at various delay times after onset of myocyte contraction. The experimental results showed that generation of PVCs had a stable threshold delay time and that PVCs were generated only when myocytes were exposed to ultrasound with delay times longer than the threshold. The results indicate that the model used in this study is useful for revealing the mechanisms by which PVCs are induced by ultrasound exposure.

  3. Fast Algorithm for Vectorcardiogram and Interbeat Intervals Analysis: Application for Premature Ventricular Contractions Classification

    Directory of Open Access Journals (Sweden)

    Irena Jekova

    2005-12-01

    Full Text Available In this study we investigated the adequacy of two non-orthogonal ECG leads from Holter recordings to provide reliable vectorcardiogram (VCG parameters. The VCG loop was constructed using the QRS samples in a fixed-size window around the fiducial point. We developed an algorithm for fast approximation of the VCG loop, estimation of its area and calculation of relative VCG characteristics, which are expected to be minimally dependent on the patient individuality and the ECG recording conditions. Moreover, in order to obtain independent from the heart rate temporal QRS characteristics, we introduced a parameter for estimation of the differences of the interbeat RR intervals. The statistical assessment of the proposed VCG and RR interval parameters showed distinguishing distributions for N and PVC beats. The reliability for PVC detection of the extracted parameter set was estimated independently with two classification methods - a stepwise discriminant analysis and a decision-tree-like classification algorithm, using the publicly available MIT-BIH arrhythmia database. The accuracy achieved with the stepwise discriminant analysis presented sensitivity of 91% and specificity of 95.6%, while the decision-tree-like technique assured sensitivity of 93.3% and specificity of 94.6%. We suggested possibilities for accuracy improvement with adequate electrodes placement of the Holter leads, supplementary analysis of the type of the predominant beats in the reference VCG matrix and smaller step for VCG loop approximation.

  4. [Competitive pacing in a patient with DDD pacemaker and bigeminal ventricular extrasystoles].

    Science.gov (United States)

    Carbone, Vincenzo; Candelmo, Fiore; Todaro, Chiara; Oreto, Giuseppe

    2008-11-01

    The ECG recorded from a patient with DDD pacemaker showed variable responses of the pacing system to bigeminal ventricular extrasystoles, dependent on the coupling interval of premature beats. For relatively short coupling intervals, the premature spontaneous event was detected by the pacemaker, inhibiting both atrial and ventricular output, and resulting in a relatively long pacing pause. In slightly less premature end-diastolic extrasystoles, in contrast, the pacing system delivered an atrial spike that was superimposed upon the spontaneous premature QRS complex (pseudo-pseudofusion); under these circumstances, the atrial spike was followed, at the end of the programmed atrioventricular interval, by a ventricular spike falling on the extrasystolic T wave apex (competitive ventricular pacing). This phenomenon, however, did not express a sensing malfunction, but was due to post-atrial ventricular blanking (PAVB), a short period initiated by the atrial spike during which ventricular sensing is temporarily disabled, so that no signal can be detected. Finally, whenever premature end-diastolic impulses occurred after PAVB, during the brief interval defined ventricular safety pacing, the spontaneous event was sensed, being followed by an earlier-than-expected ventricular spike, whose prematurity was aimed at avoiding the occurrence of an artificial impulse upon the T wave of extrasystole. In conclusion, despite several not sensed ventricular extrasystoles and competitive pacing, no sensing malfunction was present. This case demonstrates how complex can be the electrocardiographic analysis of a DDD pacemaker, owing to the many complicating phenomena related to this pacing mechanism.

  5. Ventricular fibrillation via torsade des pointes of cardiac sarcoidosis with preserved left ventricular ejection fraction.

    Science.gov (United States)

    Sekihara, Takayuki; Nakane, Eisaku; Nakasone, Kazutaka; Inoko, Moriaki

    2016-10-25

    Generally, low left ventricular ejection fraction (LVEF) is a risk for ventricular arrhythmia in patients with cardiac sarcoidosis. We present a case of cardiac sarcoidosis with preserved LVEF that evoked ventricular fibrillation (VF). A 73-year-old woman with VF presented to our emergency department. She had a history of ocular sarcoidosis, with gradual thinning of the basal intraventricular septum. LVEF was 62% on the most recent echocardiography. The electrocardiogram after defibrillation showed complete atrioventricular block (CAVB) with QT segment prolongation and frequent ventricular premature beats. VF via torsade des pointes (TdP) was suspected, and temporary intravenous ventricular pacing and magnesium sulfate infusion suppressed her VF. Cardiac sarcoidosis was diagnosed, and an implantable cardioverter defibrillator was implanted. Patients with cardiac sarcoidosis with CAVB are at risk of evoking VF via TdP regardless of LVEF. If cardiac sarcoidosis is suspected, early diagnosis and risk stratification of ventricular arrhythmia are important. 2016 BMJ Publishing Group Ltd.

  6. 单心动周期全容积成像对右心室流出道起源室性期前收缩患者左心室容积及收缩同步性的研究%Study of left ventricular systolic volume and synchrony in patients with premature ventricular complexes from the right ventricular outflow tract by instantaneous full-volume imaging

    Institute of Scientific and Technical Information of China (English)

    姚静; 许迪; 陆凤翔; 雍永宏; 吴红平; 陆美娟; 洪牮; 徐亮

    2011-01-01

    Objective To assess alternations in left ventricular volume and systolic synchrony in patients with frequent premature ventricular complexes(PVCs) from the right ventricular outflow tract(RVOT).Methods Twenty-nine patients with frequent isolated PVCs from RVOT were included and 30 healthy subjects as control.Instantaneous full-volume imaging(IFI) was performed to evaluate left ventricle volumetric parameters,including end-systolic volume (ESV),end-diastolic volume (EDV),stroke volume (SV),ejection fraction (EF),and systolic synchrony parameters,including systolic dyssynchrony index (SDI),dispersion end-systole (DISPES),mean end-systolic time (MES),pre-contraction time volume (PreContr) and post-contraction time volume (PostContr).Contraction front mapping was performed to visualize volumetric contraction sequence.All values of patients with PVCs were recorded during sinus beats (PVC-S) and premature ventricular beats (PVC-V) respectively.Results Significant differences were observed in left ventricular systolic volumetric and synchrony parameters between PVC-V and control subjects (P<0.01),as well as in MES and PreContr between PVC-S and control subjects (P<0.01).Conclusions Left ventricular systolic dysynchrony was demonstrated in patients with PVCs from RVOT.IFI was a novel tool to analyze left ventricular global and regional volumetric alternations.%目的 探讨正常人及频发右室流出道(right ventricular outflow tract,RVOT)起源室性期前收缩患者左室容积改变模式.方法 应用单心动周期全容积成像(instantaneous full-volume imaging,IFI)技术分析29例RVOT起源室性期前收缩患者在室性期前收缩、窦性心搏时以及30例正常人左室容积参数[收缩末容积(ESV)、舒张末容积(EDV)、每搏量(SV)、射血分数(EF)]和左室收缩期节段容积变化同步性参数[收缩失同步性指数(SDI)、收缩末离散度(DISPES)、平均收缩末时间(MES)、收缩前时间容积(PreContr)、收缩后时

  7. Síncope em pacientes com extra-sístoles de via de saída de ventrículo direito e sem cardiopatia estrutural aparente Syncope in patients with right ventricle outflow tract premature beats and no apparent structural cardiopathy

    Directory of Open Access Journals (Sweden)

    Ana Cristina Ludovice

    2006-11-01

    ventricular premature beats, with right ventricle outflow tract morphology (RVOT and no apparent structural cardiopathy. METHODS: Ninety patients (66 women, mean age 40.2±16.95 years of age with monomorphic premature beats originated at RVOT were evaluated prospectively. Fifty-four patients reported syncopes or near-syncopes associated to palpitations or not; twenty-seven presented palpitations with no pre-syncope or syncope, and nine were asymptomatic. All patients were submitted to echocardiogram, high resolution ECG and cardiac MRI to rule out structural cardiopathy, to exertion test to rule out adrenergic dependent ventricular tachycardia, and ECG prolonged outpatient monitoring (Holter and symptomatic events monitor to correlate symptoms and ventricular arrhythmias. Investigation on the susceptibility to neurocardiogenic syncope was evaluated by Tilt Table Test (TTT. Groups were compared regarding gender, age, premature beats frequency and complexity, at exertion or not, TTT results and clinical course. RESULTS: In the syncope and pre-syncope groups, TTT was positive for 38% of cases, and in groups with palpitations and assymptomatics, it was positive for 11% (p = 0.0257. After recommendations and treatment of neurocardiogenic syncope, 85% of syncope and pre-syncope patients and positive TTT was asymptomatic along the 40-month follow-up. Two patients with syncope and negative TTT presented spontaneous, sustained ventricular tachycardia during clinic course. CONCLUSION: The prevalence of neurocardiogenic syncope in patients with idiopathic RVOT premature beats is high. Patients with recurrent, unexplained syncope and idiopathic VE must be kept under investigation.

  8. Fungal endocarditis with right ventricular candidal mycetoma in a premature neonate

    Directory of Open Access Journals (Sweden)

    Jayashree Purkayastha

    2015-09-01

    Full Text Available Fungal mycetoma or endocarditis is rare in premature neonates and it is often associated with high mortality. In the majority of the cases diagnosis is made postmortem. Here we report a 0-week-old preterm neonate who developed Candida albicans blood stream infection complicated by endocarditis and subsequent mycetoma. Initially, this neonate had Klebsiella sepsis requiring multiple antibiotic courses. A peripherally inserted central venous catheter was used to give total parenteral nutrition. On day 24 of life, he developed candidemia, treated with 14 day course of fluconazole and shown improvement. Further, on day 60 of life he developed cholestasis, deranged liver function tests and persistent thrombocytopenia along with apnea, bradycardia and desaturations. Blood culture again grew again C. albicansEchocardiography showed large fungal vegetation on tricuspid valve with a mycetoma filling the right ventricle. He was treated with intravenous amphotericin B, fluconazole and upportive measures, but he deteriorated and succumbed after two weeks. J Microbiol Infect Dis 2015;5(3: 142-145

  9. Stepwise transition of 2:1 atrio-ventricular block to 1:1 conduction induced by ventricular premature beats in a patient with atypical AVNRT.

    NARCIS (Netherlands)

    Sorgente, A.; Chierchia, G.B.; Asmundis, C. de; Yazaki, Y.; Sarkozy, A.; Brugada, P.

    2010-01-01

    A 55-year-old man with a 2-year history of recurrent paroxysmal palpitations and with an electrocardiogram documentation of atypical atrioventricular nodal re-entrant tachycardia (AVNRT) was referred to us for catheter ablation. After an initial ablation attempt, several episodes of atypical AVNRT w

  10. Increased Ventricular Premature Contraction Frequency During REM Sleep in Patients with Coronary Artery Disease and Obstructive Sleep Apnea

    Directory of Open Access Journals (Sweden)

    Mari A. Watanabe

    2008-11-01

    Full Text Available Background Patients with obstructive sleep apnea are reported to have a peak of sudden cardiac death at night, in contrast to patients without apnea whose peak is in the morning. We hypothesized that ventricular premature contraction (VPC frequency would correlate with measures of apnea and sympathetic activity.Methods Electrocardiograms from a sleep study of 125 patients with coronary artery disease were evaluated. Patients were categorized by apnea-hypopnea index (AHI into Moderate (AHI 15 apnea groups. Sleep stages studied were Wake, S1, S2, S34, and rapid eye movement (REM. Parameters of a potent autonomically-based risk predictor for sudden cardiac death called heart rate turbulence were calculated.Results There were 74 Moderate and 51 Severe obstructive sleep apnea patients. VPC frequency was affected significantly by sleep stage (Wake, S2 and REM, F=5.8, p<.005 and by AHI (F=8.7, p<.005. In Severe apnea patients, VPC frequency was higher in REM than in Wake (p=.011. In contrast, patients with Moderate apnea had fewer VPCs and exhibited no sleep stage dependence (p=.19. Oxygen desaturation duration per apnea episode correlated positively with AHI (r2=.71, p<.0001, and was longer in REM than in non-REM (p<.0001. The heart rate turbulence parameter TS correlated negatively with oxygen desaturation duration in REM (r2=.06, p=.014.Conclusions Higher VPC frequency coupled with higher sympathetic activity caused by longer apnea episodes in REM sleep may be one reason for increased nocturnal death in apneic patients.

  11. Influence of calcium preconditioning and streptomycin on ventricular dilation-induced arrhythmias in isolated rat hearts

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To investigate the mechanism of ventricular dilation-induced arrhythmias by dilating isolated rat hearts. Methods Isolated rat hearts were perfused by Langerdorff method. After equilibration, 80 hearts were randomly divided into four groups as follows: (1) control group (n=20), (2) Ca2+ preconditioning (CPC) group (n=20), (3) streptomycin group (n=20), and (4) CPC + streptomycin group (n=20). A latex balloon which can be filled with fluid was anchored in the left ventricle through the left atrium and mitral valve. Epicardial ECG of the left ventricle, left ventricular pressure, coronary flow and heart rate were recorded before and during ventricular dilation by injecting fluid into the latex balloon. The rate and duration of ventricular dilation-induced arrhythmias were recorded. Results Under the same increase in ventricular end-diastolic pressure made by inflation of the balloon, the rate of arrhythmias was 100% and duration of arrhythmias was 2.56±0.46 s in the control group. Both the rates of premature ventricular beat (90 %) and ventricular tachycardia 70 % ) were high. Compared with the control group, the total rate (60 % ) of arrhythmias was lower, and duration (1.67±0.61 s ) of arrhythmias was shorter in the CPC group. Both the rates of premature ventricular beat (60%) and ventricular tachycardia (40%) were low comparatively. The rate of arrhythmias (45 %) was lower and duration ( 1.64±0.42 s)of arrhythmias was shorter, and the rates of premature ventricular beat (30 % ) or ventricular tachycardia (35 %) were lower in the streptomycin group than in the control one. The least ventricular dilation-induced arrhythmias occurred in the CPC + streptomycin group. The rate of arrhythmias (10%) was the lowest and duration (1.01±0.37s) of arrhythmias was the shortest; both the rates of premature ventricular beat (5%) and ventricular tachycardia (10%) were the lowest. Conclusions Ventricular dilation may induce arrhythmias in isolated rat hearts. Stretch

  12. Use of self-gated radial cardiovascular magnetic resonance to detect and classify arrhythmias (atrial fibrillation and premature ventricular contraction).

    Science.gov (United States)

    Piekarski, Eve; Chitiboi, Teodora; Ramb, Rebecca; Feng, Li; Axel, Leon

    2016-11-25

    Arrhythmia can significantly alter the image quality of cardiovascular magnetic resonance (CMR); automatic detection and sorting of the most frequent types of arrhythmias during the CMR acquisition could potentially improve image quality. New CMR techniques, such as non-Cartesian CMR, can allow self-gating: from cardiac motion-related signal changes, we can detect cardiac cycles without an electrocardiogram. We can further use this data to obtain a surrogate for RR intervals (valley intervals: VV). Our purpose was to evaluate the feasibility of an automated method for classification of non-arrhythmic (NA) (regular cycles) and arrhythmic patients (A) (irregular cycles), and for sorting of common arrhythmia patterns between atrial fibrillation (AF) and premature ventricular contraction (PVC), using the cardiac motion-related signal obtained during self-gated free-breathing radial cardiac cine CMR with compressed sensing reconstruction (XD-GRASP). One hundred eleven patients underwent cardiac XD-GRASP CMR between October 2015 and February 2016; 33 were included for retrospective analysis with the proposed method (6 AF, 8 PVC, 19 NA; by recent ECG). We analyzed the VV, using pooled statistics (histograms) and sequential analysis (Poincaré plots), including the median (medVV), the weighted mean (meanVV), the total number of VV values (VVval), and the total range (VVTR) and half range (VVHR) of the cumulative frequency distribution of VV, including the median to half range (medVV/VVHR) and the half range to total range (VVHR/VVTR) ratios. We designed a simple algorithm for using the VV results to differentiate A from NA, and AF from PVC. Between NA and A, meanVV, VVval, VVTR, VVHR, medVV/VVHR and VVHR/VVTR ratios were significantly different (p values = 0.00014, 0.0027, 0.000028, 5×10(-9), 0.002, respectively). Between AF and PVC, meanVV, VVval and medVV/VVHR ratio were significantly different (p values = 0.018, 0.007, 0.044, respectively). Using our algorithm

  13. Factors influencing left ventricular hypertrophy in children and adolescents with or without family history of premature myocardial infarction

    Directory of Open Access Journals (Sweden)

    Seyyed Mohsen Hosseini

    2014-01-01

    Result : The results showed that among the studied variables, gender, age, body mass index, and blood pressure were associated with the left ventricular hypertrophy. Conclusion: Considering the results and previous studies in this field, it was observed that left ventricular hypertrophy exists at early ages, which is very dangerous and can lead to heart diseases at early ages. Factors such as being overweight, having high blood pressure, and being male cause left ventricular hypertrophy and lead to undiagnosable heart diseases.

  14. Cognition and experience in management of premature ventricular contractions%临床上对室性早搏的认识和治疗经验

    Institute of Scientific and Technical Information of China (English)

    何乐; 李国庆

    2014-01-01

    室性早搏是最常见的心律失常之一,其临床表现多变,依据自身形态特点、发作频率等,可表现为单纯的无症状室性早搏到左心功能障碍,甚至出现充血性心力衰竭。目前临床上对于室性早搏的认识及治疗尚缺乏普遍共识,其治疗方案选择更多的基于临床表现。对于室性早搏发生频率高,症状较重,或怀疑可能导致心肌病的患者,射频消融术是最有效的选择,成功率可达80%~85%,多病例在成功消融后可明显改善左室功能。%Premature ventricular complexes are one of the most common arrhythmia. The clinical presentation may range from asymptomatic to left ventricular dysfunction, even with congestive heart failure due to their morphological characteristics, seizure frequency, etc. Current understanding of premature ventricular complexes and therapy is still a lack of consensus, the decision of treatment based on clinical presentation. Radiofrequency ablation has been seen as an effective option for the treatment of frequent PVCs or thus with suspicion of PVC-mediated cardiomyopathy. The clinical experience show that PVCs ablation has been successful in 80%-85% of cases, and multiple cases can obviously improve left ventricular function after successful ablation.

  15. Single beat 3D echocardiography for the assessment of right ventricular dimension and function after endurance exercise: Intraindividual comparison with magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Schattke Sebastian

    2012-02-01

    Full Text Available Abstract Background Our study compares new single beat 3D echocardiography (sb3DE to cardiovascular magnetic resonance imaging (CMR for the measurement of right ventricular (RV dimension and function immediately after a 30 km run. This is to validate sb3DE against the "gold standard" CMR and to bring new insights into acute changes of RV dimension and function after endurance exercise. Methods 21 non-elite male marathon runners were examined by sb3DE (Siemens ACUSON SC2000, matrix transducer 4Z1c, volume rates 10-29/s, CMR (Siemens Magnetom Avanto, 1,5 Tesla and blood tests before and immediately after each athlete ran 30 km. The runners were not allowed to rehydrate after the race. The order of sb3DE and CMR examination was randomized. Results Sb3DE for the acquisition of RV dimension and function was feasible in all subjects. The decrease in mean body weight and the significant increase in hematocrit indicated dehydration. RV dimensions measured by CMR were consistently larger than measured by sb3DE. Neither sb3DE nor CMR showed a significant difference in the RV ejection fraction before and after exercise. CMR demonstrated a significant decrease in RV dimensions. Measured by sb3DE, this decrease of RV volumes was not significant. Conclusion First, both methods agree well in the acquisition of systolic RV function. The dimensions of the RV measured by CMR are larger than measured by sb3DE. After exercise, the RV volumes decrease significantly when measured by CMR compared to baseline. Second, endurance exercise seems not to induce acute RV dysfunction in athletes without rehydration.

  16. Concomitant Right Ventricular Outflow Tract Cryoablation during Pulmonary Valve Replacement in a Patient with Tetralogy of Fallot

    Science.gov (United States)

    Shin, Hong Ju; Song, Seunghwan; Shin, Yu Rim; Park, Han Ki; Park, Young Hwan

    2017-01-01

    A 38-year-old female patient with a history of tetralogy of Fallot repair at 10 years of age underwent pulmonary valve replacement with a mechanical prosthesis, tricuspid annuloplasty, and right ventricular outflow tract cryoablation due to pulmonary regurgitation, tricuspid regurgitation, and multiple premature ventricular contractions with sustained ventricular tachycardia. After surgery, she had an uneventful postoperative course with arrhythmia monitoring. She was discharged without incident, and a follow-up Holter examination showed a decrease in the number of ventricular ectopic beats from 702 to 41. PMID:28180102

  17. Comparison of sinoatrial conduction time measured by Holter method and premature stimulation method.

    Science.gov (United States)

    Kramarz, Elżbieta; Piotrowicz, Ryszard; Krzyzanowski, Krystian; Kramarz, Paulina

    2015-05-01

    The reliability of noninvasive Holter method for the calculation of sinoatrial conduction time (SACT) has not been confirmed by results of invasive electrophysiological studies of sinus nodal function. The aim of this study was to compare the values of SACT obtained by Holter method with values estimated by premature atrial stimulation method. The study population consisted of 61 patients, in whom the 24-hour ambulatory ECG monitoring had shown the occurrence of atrial premature beats. All these subjects were undergoing electrophysiological study including programmed atrial and ventricular stimulation. The measurements of SACT were obtained using spontaneous atrial premature beats (Holter method) and high right atrial stimulation (Strauss method). There was a good correlation between measurements of SACT by Holter method and Strauss method (r = 0.79; P Holter method and Strauss method were significantly (P Holter method may be adequate for reliable calculation of SACT. © 2014 Wiley Periodicals, Inc.

  18. Effects of Na+ channel blockers on extrasystolic stimulation-evoked changes in ventricular conduction and repolarization.

    Science.gov (United States)

    Osadchii, Oleg E

    2014-03-01

    Antiarrhythmic agents which belong to class Ia (quinidine) and Ic (flecainide) reportedly increase propensity to ventricular tachyarrhythmia, whereas class Ib agents (lidocaine and mexiletine) are recognized as safe antiarrhythmics. Clinically, tachyarrhythmia is often initiated by a premature ectopic beat, which increases spatial nonuniformities in ventricular conduction and repolarization thus facilitating reentry. This study examined if electrical derangements evoked by premature excitation may be accentuated by flecainide and quinidine, but unchanged by lidocaine and mexiletine, which would explain the difference in their safety profile. In perfused guinea pig hearts, a premature excitation evoked over late repolarization phase was associated with prolonged epicardial activation time, reduced monophasic action potential duration (APD), and increased transepicardial dispersion of the activation time and APD. Flecainide and quinidine increased conduction slowing evoked by extrasystolic stimulation, prolonged APD, and accentuated spatial heterogeneities in ventricular conduction and repolarization associated with premature excitation. Spontaneous episodes of nonsustained monomorphic ventricular tachycardia were observed in 50% of heart preparations exposed to drug infusion. In contrast, lidocaine and mexiletine had no effect on extrasystolic stimulation-evoked changes in ventricular conduction and repolarization or arrhythmic susceptibility. These findings suggest that flecainide and quinidine may promote arrhythmia by exaggerating electrophysiological abnormalities evoked by ectopic beats.

  19. Cerebrospinal fluid levels of amyloid precursor protein are associated with ventricular size in post-hemorrhagic hydrocephalus of prematurity.

    Directory of Open Access Journals (Sweden)

    Diego M Morales

    Full Text Available Neurological outcomes of preterm infants with post-hemorrhagic hydrocephalus (PHH remain among the worst in infancy, yet there remain few instruments to inform the treatment of PHH. We previously observed PHH-associated elevations in cerebrospinal fluid (CSF amyloid precursor protein (APP, neural cell adhesion molecule-L1 (L1CAM, neural cell adhesion molecule-1 (NCAM-1, and other protein mediators of neurodevelopment.The objective of this study was to examine the association of CSF APP, L1CAM, and NCAM-1 with ventricular size as an early step toward developing CSF markers of PHH.CSF levels of APP, L1CAM, NCAM-1, and total protein (TP were measured in 12 preterm infants undergoing PHH treatment. Ventricular size was determined using cranial ultrasounds. The relationships between CSF APP, L1CAM, and NCAM-1, occipitofrontal circumference (OFC, volume of CSF removed, and ventricular size were examined using correlation and regression analyses.CSF levels of APP, L1CAM, and NCAM-1 but not TP paralleled treatment-related changes in ventricular size. CSF APP demonstrated the strongest association with ventricular size, estimated by frontal-occipital horn ratio (FOR (Pearson R = 0.76, p = 0.004, followed by NCAM-1 (R = 0.66, p = 0.02 and L1CAM (R = 0.57,p = 0.055. TP was not correlated with FOR (R = 0.02, p = 0.95.Herein, we report the novel observation that CSF APP shows a robust association with ventricular size in preterm infants treated for PHH. The results from this study suggest that CSF APP and related proteins at once hold promise as biomarkers of PHH and provide insight into the neurological consequences of PHH in the preterm infant.

  20. The Relationship of Left Ventricular Remodeling and Cardiac Function with Ventricular Arrhythmia in Ischemic Cardiomyopathy%缺血性心肌病左室重构和心功能与室性心律失常的关系

    Institute of Scientific and Technical Information of China (English)

    楚涛

    2012-01-01

    目的:探讨缺血性心肌病(ICM)患者左心室重构和心功能与室性心律失常的关系.方法:120例ICM患者分别按左心功能和左心室舒张末期内径(left ventricle end diastolic dimension,LVEDd)分组,分析各组患者发生室性心律失常的情况.结果:ICM患者的复杂型室性早搏、室内传导阻滞、室性早搏并发室内传导阻滞的发生率与LVEDd有明显相关性,差异有显著性(P<0.05);复杂型室性早搏的发生率与左心功能有关,差异有显著性(P<0.05),而室内传导阻滞以及室性早搏并发室内传导阻滞的发生率与左心功能无关,差异无显著性(P>0.05);简单型室性早搏的发生率与LVEDd和左心功能无关,差异无显著性(P>0.05).结论:ICM患者复杂型室性早搏发生与LVEDd及心功能有明显相关性,LVEDd重度增大者更易发生室性早搏及室内传导阻滞.%Objective: To investigate the relationship of left ventricular remodeling and cardiac function with ventricular arrhythmias in patients with ischemic cardiomyopathy (ICM). Methods; Total 120 cases with ICM were divided into groups according to left ventricle end-diastolic dimension (LVEDd) and left ventricular function, and the occurrence of ventricular arrhythmias in each group was investigated. Results; The occurrence of complex ventricular premature beat, intraventricular block and ventricular premature beat complicated with intraventricular block was related to LVEDd ( P 0. 05). Simple type of ventricular premature beat was not related to LVEDd and left heart function (P > 0. 05). Conclusions: The occurrence of complex ventricular premature beat is related to LVEDd and left heart function. When LVEDd is severe enlargement, ventricular premature beat complicated with intraventricular block is more likely to occur.

  1. Association between frequency of atrial and ventricular ectopic beats and biventricular pacing percentage and outcomes in patients with cardiac resynchronization therapy

    DEFF Research Database (Denmark)

    Ruwald, Martin H; Mittal, Suneet; Ruwald, Anne-Christine

    2014-01-01

    -defibrillator device with data available on biventricular pacing percentage and pre-implantation 24-h Holter recordings were included. Using logistic regression, we estimated the influence of ectopic beats on the percentage of biventricular pacing. Reverse remodeling was measured as reductions in atrial and left.......001) in patients with >1.5% ectopic beats compared with those with reverse remodeling (percent reduction in LVESV 31 ± 15%) than patients with ... biventricular pacing (reverse remodeling and higher risk of HF/death and VTA. This supports pre-implantation Holter monitoring of patients selected for CRT for optimal outcome. (MADIT-CRT: Multicenter Automatic Defibrillator Implantation With Cardiac Resynchronization...

  2. A Statistical Index for Early Diagnosis of Ventricular Arrhythmia from the Trend Analysis of ECG Phase-portraits

    CERN Document Server

    Cappiello, Grazia; Mazomenos, Evangelos B; Maharatna, Koushik; Koulaouzidis, George; Morgan, John; Puddu, Paolo Emilio

    2016-01-01

    In this paper, we propose a novel statistical index for the early diagnosis of ventricular arrhythmia (VA) using the time delay phase-space reconstruction (PSR) technique, from the electrocardiogram (ECG) signal. Patients with two classes of fatal VA - with preceding ventricular premature beats (VPBs) and with no VPBs have been analysed using extensive simulations. Three subclasses of VA with VPBs viz. ventricular tachycardia (VT), ventricular fibrillation (VF) and VT followed by VF are analyzed using the proposed technique. Measures of descriptive statistics like mean ({\\mu}), standard deviation ({\\sigma}), coefficient of variation (CV = {\\sigma}/{\\mu}), skewness ({\\gamma}) and kurtosis (\\{beta}) in phase-space diagrams are studied for a sliding window of 10 beats of ECG signal using the box-counting technique. Subsequently, a hybrid prediction index which is composed of a weighted sum of CV and kurtosis has been proposed for predicting the impending arrhythmia before its actual occurrence. The early diagnos...

  3. The treatment and quality of life in premature beats patients with anxiety and depression symptoms%心脏早搏患者伴焦虑抑郁的治疗及其对生活质量的影响

    Institute of Scientific and Technical Information of China (English)

    王福军; 罗亚雄; 向红菊; 石翔

    2012-01-01

    Objective To observe and assess the psychological disorders such as anxiety and depression in arrhythmic patients without organic heart disease as well as clinical efficacy and the quality of life with pharmacotherapy using antidepressants.Methods Two hundred and twelve patients with premature beats but without organic heart disease were randomly assigned to the observation group and control group with 106 patients in each group.All the patients were given with metoprolol and fluxetine or deanxit and metoprolol separately.The clinical signs、electrocardiograph( ECG),dynamic electrocardiogram( DCG),self-rating anxiety scale (SAS) and Self - rating Depression Scale (SDS) score were observed before treatment and 2 months after treatment.The Evaluation of Chinese questionnaire of quality of life in patients with cardiovascular disease was adopted to evaluate patients' quality of life.Results Compared to pre -treatment,the observation group's SAS,SDS score decreased significantly[ SAS:(39 ±9) vs (52 ± 10) ;SDS:(39 ± 10) vs (58 ± 11) ;P < 0.01 ],however there were no significant changes in control group (P >0.05).Compared with control group,the observation group's SAS,SDS score decreased significantly [ SAS:(39 ±9) vs (53 ± 10) ;SDS:(39 ± 10) vs (58 ±9) ; P <0.01 ].The clinical improvement rate of observation group's symptoms regarding chest pain、thorax suffocation and breath hard were respectively 84.9%,95.9%,96.4% and 92.1%,which were significantly higher than control group's 30.2%,42.6%,46.0% and 48.6%( P < 0.01 ).The effective rate of observation group's premature beats was 84.0% ( 89/106),which was also significantly higher than control group's 53.8% (57/106).The observation group's score of Evaluation of Chinese questionnaire of quality of life in patients with cardiovascular disease were significantly higher than that of control group (P < 0.01 ).Conclusions The patients with premature beats who suffer from sustained

  4. Incidence and clinical significance of repetitive ventricular response in patients without identifiable organic heart disease.

    Science.gov (United States)

    Treese, N; Geibel, A; Kasper, W; Meinertz, T; Pop, T; Meyer, J

    1984-10-01

    We determined the incidence of repetitive ventricular response (RVR) after programmed electrical stimulation and the incidence of spontaneous ventricular arrhythmias during 24 hr Holter monitoring in 38 patients in whom extensive non-invasive and invasive diagnostic tests had excluded abnormalities suggestive of organic heart disease. A standardized stimulation protocol with single (S1S2) and double (S1S2S3) extrastimuli during ventricular drive at cycle lengths of 600, 500 and 430 msec with a current strength below 5 mA at the right ventricular apex was employed. RVR occurred in 20 patients (58%) after S1S2 and in 30 patients (79%) after S1S2S3 stimulation. Eighteen patients (47%) showed RVR with 2 echo beats and 1 patient had 3 echo beats. RVR was due to bundle branch reentry (BBR) in 20 patients independent of the mode of stimulation. RVR due to intraventricular reentry (IVR) was found in 17 patients (47%) only after S1S2S3 stimulation. The incidence of both BBR and IVR was influenced by the basic ventricular driving rate, decreasing with shorter basic cycle lengths. 17 patients had no ventricular premature depolarizations (VPDs), 12 patients had uniform, 4 multiform (Lown III), 2 consecutive (Lown IVA) VPDs, and 1 patient had parasystolic rhythm. There was no relation to the incidence of repetitive ventricular response. We conclude that in patients without identifiable organic heart disease RVR with more than 2 consecutive beats is rarely found if single and double extrastimuli are employed during ventricular drive. Both bundle branch and intraventricular reentry with one or two echo beats are a common finding in this population without relation to the incidence of spontaneous ventricular arrhythmias.

  5. The incidence and mechanisms of spike potentials in origin regions of outflow tract premature ventricular contraction%流出道室性早搏起源处异常电位的分布和意义

    Institute of Scientific and Technical Information of China (English)

    贾玉和; 韦维; 丁立刚; 赵英杰; 王靖; 楚建民; 张澍

    2011-01-01

    Objective To investigate the incidence and mechanisms of spike potential (SP) in premature ventricular contractions (PVCs) originating from outflow tract in structurally normal heart. Methods Fifty-four consecutive cases with symptomatic PVCs originating from ventricular outflow tract who have been successfully performed radiofrequency catheter ablation were investigated. The incidence and patterns of SP recorded at the successful ablation sites were analyzed. The SP was divided into 4 types. The pattern of SP recorded in sinus rhythm but not in PVCs was defined as type I. SP occurred in both sinus rhythm and PVCs was defined as type II which was further divided into 2 subtypes: type II a and type II b. SP buried within QRS complex wave during sinus beats and reversal preceding to QRS complex wave during PVC named type II a , while SP remained within QRS complex wave without reversion during PVC named type II b. SP occurred neither in sinus rhythm nor PVCs was defined as type Ⅲ. SP existed in PVCs without occurred in sinus rhythm was defined as type IV. Results In SP patterns of all 54 cases, 2 cases were type I , 21 were type Ⅱa, 12 were type Ⅱb , 6 were type Ⅲ , 13 were type IV. SP incidence in final successful ablation sites during PVCs was 85.2% (46/54) . Successful ablation site located at right ventricular outflow tract in 44 patients and left ventricular outflow tract in 10 patients. 4 of fifty-four cases recurrence after first ablation procedure, and 3 of them received ablation again. Patient 1 changed its SP pattern from type I to Ⅱa during second ablation session. Also, Patient 2 and patient 3 changed their SP patterns from II b to II a. Conclusion SP can be recorded at the origin site in the majority of outflow tract premature ventricular contractions.The reversal of SP preceding to QRS complex wave of PVC may be a successful ablation indicator. [ Chinese Journal of Cardiac Pacing and Electrophysiology,2011,25(4) ;323 -325]%目的 分析流出

  6. A pilot of ventricular premature beat with history of myocarditis%飞行员心肌炎后遗症引发室性早搏一例

    Institute of Scientific and Technical Information of China (English)

    李佩倞

    2004-01-01

    @@ 一、临床资料 患者男性,39岁,强-5飞行员,飞行时间2300 h.1992年无明显诱因出现心慌、乏力,脉搏漏跳,诊断为心肌炎,经抗生素、能量合剂治疗后好转,飞行合格.1996年11月,疗养体检,心电图示:T波改变,频发室性早搏,送上级医院诊断为:心肌炎后遗症.治疗半月余好转,飞行合格.1998年8月疗养期间出现心悸,心电图示:频发室性早搏.

  7. Beat Dreams?

    DEFF Research Database (Denmark)

    Sørensen, Bent

    2009-01-01

    Two of the founding members of the Beat Generation of the 1950s wrote dream books with almost identical titles: Jack Kerouac's Book of Dreams (1961) and William Burroughs' My Education: A Book of Dreams (1995). This paper queries the function of such dream books, both from a perspective of seeing...

  8. Study of intracardiac flow patterns of left ventricle in patients with premature ventricular complexes from the right ventricular outflow tract%右心室流出道起源室性期前收缩患者左心室腔流场分布模式的研究

    Institute of Scientific and Technical Information of China (English)

    姚静; 许迪; 李相权; 吴红平; 雍永宏; 季玲; 陈莉

    2011-01-01

    Objective To evaluate the patterns of intracardiac flow of left ventricle (LV) in patients with premature ventricular complexes (PVCs) from the right ventricular outflow tract (RVOT) by analyzing the vortex during isovolumetric contraction phase and the distribution rules of flow-time curves in each layer of LV.Methods Twenty-seven patients with frequent isolated PVCs from RVOT were involved and 25 healthy subjects as control.The color Doppler image of LV at apical four-chamber view was acquired.Vector flow mapping (VFM) was performed to assess the parameters of vortex during isovolumic contraction phase, including diameter (transverse and vertical diameter), velocity (maximal positive and negative velocity) and the number of vortex rings.Positive flow during systole and negative flow during diastole of LV in each layer were measured by flow-time curve.All values of patients with PVCs were recorded during sinus beats (PVC-S) and PVC (PVC-V) respectively.Results Significant differences were demonstrated in all parameters of vortex between the PVC-V and control subjects.And the flow-time curves disarrayed in PVC-V.The velocity of vortex in PVC-S was lower than that in control subjects.And the distribution pattern of flow-time curves in LV of PVC-S differed from that of control subjects.Conclusions Alternation of intracardiac fluid pattern in LV was demonstrated in patients with PVCs from RVOT during both sinus beats and PVC.VFM can be used to analyze the intracardiac flow field in normal and pathological electrical activation.%目的 分析正常人及右室流出道(right ventricular outflow tract,RVOT)起源室性期前收缩(premature ventricular complexes,PVCs)患者左心室腔等容收缩期涡流及左心室腔不同层面时间-血流曲线分布规律,探讨RVOT起源PVCs对左心室腔流场分布模式的影响。方法 分别获取27例RVOT起源PVCs患者在窦性心搏、室性期前收缩时及25例正常人的心尖四腔观二维彩色多普勒

  9. Fusion beat in patients with heart failure treated with left ventricular pacing: may ECG morphology relate to mechanical synchrony? A pilot study

    Directory of Open Access Journals (Sweden)

    Sassone Biagio

    2008-01-01

    Full Text Available Abstract Background Electrical fusion between left ventricular pacing and spontaneous right ventricular activation is considered the key to resynchronisation in sinus rhythm patients treated with single-site left ventricular pacing. Aim Use of QRS morphology to optimize device programming in patients with heart failure (HF, sinus rhythm (SR, left bundle branch block (LBBB, treated with single-site left ventricular pacing. Methods and Results We defined the "fusion band" (FB as the range of AV intervals within which surface ECG showed an intermediate morphology between the native LBBB and the fully paced right bundle branch block patterns. Twenty-four patients were enrolled. Echo-derived parameters were collected in the FB and compared with the basal LBBB condition. Velocity time integral and ejection time did not improve significantly. Diastolic filling time, ejection fraction and myocardial performance index showed a statistically significant improvement in the FB. Interventricular delay and mitral regurgitation progressively and significantly decreased as AV delay shortened in the FB. The tissue Doppler asynchrony index (Ts-SD-12-ejection showed a non significant decreasing trend in the FB. The indications provided by the tested parameters were mostly concordant in that part of the FB corresponding to the shortest AV intervals. Conclusion Using ECG criteria based on the FB may constitute an attractive option for a safe, simple and rapid optimization of resynchronization therapy in patients with HF, SR and LBBB.

  10. Control of ventricular ciliary beating by the Melanin Concentrating Hormone-expressing neurons of the lateral hypothalamus : a functional imaging survey.

    Directory of Open Access Journals (Sweden)

    Gregory eConductier

    2013-11-01

    Full Text Available The cyclic peptide Melanin-Concentrating Hormone (MCH is known to control a large number of brain functions in mammals such as food intake and metabolism, stress response, anxiety, sleep/wake cycle, memory and reward. Based on neuroanatomical and electrophysiological studies these functions were attributed to neuronal circuits expressing MCHR1, the single MCH receptor in rodents. In complement to our recently published work (Conductier et al. 2013 we provided here new data regarding the action of MCH on ependymocytes in the mouse brain. First, we establish that MCHR1 mRNA is expressed in the ependymal cells of the third ventricle epithelium. Second, we demonstated a tonic control of MCH-expressing neurons on ependymal cilia beat frequency using in vitro optogenics. Finally, we performed in vivo measurements of CSF flow using fluorescent micro-beads in wild-type and MCHR1 knockout mice. Collectively, our results demonstrated that MCH-expressing neurons modulate ciliary beating of ependymal cells at the third ventricle and could contribute to maintain cerebro-spinal fluid homeostasis.

  11. Electrocardiographic characteristics and radiofrequency catheter ablation of ventricular tachycardia and frequent ventricular premature contractions originating from left ventricular outflow tract%射频消融治疗起源于左室流出道的室性心动过速和频发室性期前收缩

    Institute of Scientific and Technical Information of China (English)

    陈宏; 张薇薇; 李荣琴; 李占全; 崔然

    2008-01-01

    目的 探讨源自左室流出道部位的室性心动过速(室速)和室性期前收缩(室早)的心电图特点和射频消融的安全性.方法 对9例于左室流出道部位消融的室速/室早病例的心电图和射频消融情况进行归纳总结.结果 消融成功部位6例在左冠窦内,3例在主动脉瓣下.心电图特点:(1)Ⅱ、Ⅲ、avF导联均呈高R波;(2)aVR和aVL导联均呈QS型,且aVL振幅多大于aVR;(3)Ⅰ导联多呈QS型;(4)V1导联R波偏高:R/S>0.62;(5)胸前导联R波移行不规则;(6)V5、V6多呈R型.9例均消融成功,无复发病例,无左主干及主动脉瓣损伤.结论 源自左室流出道的室速/室早具有独特的心电图表现,射频消融能安全有效地根治此类心律失常.%Objective To investigate the electrocardiographic(ECG) characteristics and assess the safety of radiofrequency catheter ablation (RFCA) of ventricular tachyeardia (VT), and frequent ventricular premature con- tractious(VPCs) originating from left ventricular outflow tract(LVOT). Methods Twelve-lead ECG analysis and RFCA were performed in 9 patient with VT or VPCs originating from LVOT. Results The sites to be successfully ablated were in left valsalva sinus in 6 patients,and subaortic valve in 3 patient. ECG revealed tall R wave in leads Ⅱ, Ⅲ ,aVF, V5 and V6. QS morphology in both leads aVR and aVL,QS morphology in lead Ⅰ in most cases. R wave in lead Ⅰ was relative tall, the R/S wave amplitude in lead V1 was over 0.62 ,and precordia R wave transition was irregular. All 9 patients were successfully ablated. No death or recurrenced case during follow-up. Conclusion Ventricular taehycardia and frequent ventricular premature rcontractions originating from left ventricutar outflow tract could be known by some specific ECG characteristics and could be radically treated safely by RFCA.

  12. 单导管射频消融治疗右室流出道室性期前收缩%Radiofrequency catheter ablation of premature ventricular contractions from right ventricular outflow tract by single catheter electrode

    Institute of Scientific and Technical Information of China (English)

    梁锦军; 黄鹤; 杨波; 万军; 唐艳红; 江洪; 黄从新

    2011-01-01

    AIM: To assess the clinical effects of ablation of premature ventricular contractions ( PVCs ) in right ventricular outflow tracl ( RVOT) using a single catheter electrode. METHODS: Single catheter technique for radiofrequency catheter ablation ( RFCA) was performed in 65 consecutive patients with severe symptomatic monomorphic PVCs originating within the RVOT. A 7-Fr, 4-mm-tip catheter was used for both mapping and ablation. Target sites were localized by pace mapping. Pace mapping demonstrated identical QRS complex configurations during pacing and during arrhythmia in at least 11 leads. RESULTS; Acute ablation success was achieved in 63/65 patients (96. 9% ). During the follow-up of ( 28 ± 13) months, recurrence and reablation were done in three patients (4. 6% ). Two of these patients remained arrhythmia-free. Surgical time was (50+27) min, and fluoroscopy time was (8. 1 ±3. 8) min. No ablation-related complications occurred during the follow-up of 15 -40 months. CONCLUSIONS; Single catheter technique is safe and effective for mapping and ablation of PVCs from RVOT.%目的:观察单导管射频消融治疗右室流出道室性期前收缩(室性早搏,室早)的安全性和临床效果.方法:经常规体检、生化检查、X线胸片、心脏彩超、长程心电图等各种检查后,入选65例患者,采用温控消融导管以起搏为主的方法进行标测,并对单导管射频消融的安全性和临床效果进行总结.结果:消融即刻成功率97%( 63/65),其中2例放弃消融术;随访15~40个月,有3例复发并再次手术,成功2例,总成功率为95%( 62/65),无复发.电生理检测和消融时间:(50±27) min;曝光时间:(8.1±3.8)min,所有患者术中及术后均未发生消融相关并发症.结论:单导管射频消融治疗右室流出道室早安全有效,并能减少消融操作及X线暴露时间.

  13. 特发性室性早搏病人左心脏结构和功能的研究%Impact of Idiopathic Ventricular Premature Contractions on the Structure and Function of Left Ventricular

    Institute of Scientific and Technical Information of China (English)

    李可; 胡元会; 李偲偲; 贾秋蕾; 魏艺

    2016-01-01

    目的:探讨 Lown氏分级下特发性室性早搏(IPVCs)对左心结构和功能的影响。方法选取中国中医科学院广安门医院2009年1月—2015年2月心血管科住院治疗的特发性室性早搏病人111例作为观察组,并根据 Lown氏分级分成3亚组:B组>C组,A组、B组分别与 C组比较差异有统计学意义(P<0.01)。室性早搏分级与 LVESD(r=0.360,P=0.000)、LVEDD(r=0.350,P=0.000)呈正相关,与LVEF(r=-0.276,P=0.003)呈负相关。结论特发性室性早搏对左心结构与功能有影响,并且频率越高,复杂度越大,影响越明显,并有病理性变化趋势。%Objective This article aims to investigate,according to the grade of Lown’s stratification,the impact of clinical characteris-tics of idiopathic ventricular premature contractions(IPVCs)on cardiac structure,as wel as cardiac function.Methods One hundred and eleven IPVCs inpatients in group 1 and 33 patients without IPVCs in group 2 were studied.According to the grade of Lown’s stratification,111 IPVCs inpatients were divided into three groups:Group A(ven-tricular tachycardia).The general information and the data of the biochemistry of serum were col ected,and the cardiac structure and function is determined by echocardiogram and compared.Results Left ventricular (LV)end systolic diameter(LVESD),LV end diastolic dimension (LVEDD),LV ejection fraction (LVEF)in group 1 were less than that in group 2(P<0.05).LVESD is as fol ows group A,group B,group C in a ascending order,and the difference between group A and C group was statistical y significant(P<0.01), also between B group and C group.LVEDD is as fol ows group A,group B,group C in a ascending order,and the difference between group A and group C was statistical y significant(P<0.05).LVEF is as fol ows group A,group B,group C in a decending order,and the difference between group A and group C was statistical y significant(P<0.01),also between group B and

  14. 射频消融治疗室性早搏触发特发性室性心动过速/心室颤动的病例分析%Radiofrequency catheter ablation of premature ventricular contractions for ventricular tachycardia/ventricular fibrillation

    Institute of Scientific and Technical Information of China (English)

    梁锦军; 黄鹤; 杨波; 万军; 唐艳红; 吴钢; 江洪; 黄从新

    2010-01-01

    Objective This study was to assess the clinical effects of ablation of premature ventricular contractions (PVCs) for ventricular tachycardia (VT) /ventricular fibrillation (VF). Methods This study included three cases, case one with severely symptomatic monomorphic PVCs originating within the right ventricular outflow tract (RVOT), which was treated by ablation and ICD. Case two with severely symptomatic monomorphic PVCs originating within the RVOT,who underwent simplicity ablation, and experienced ventricular fibrillation and therefore ICD was implanted. Case three with idiopathic ventricular fibrillation triggered by PVCs was successfully treated by catheter ablation. Results All of the three cases are survival without VT/VF during two-year follow up. Conclusions Successful catheter ablation of PVCs might prevent life-threatening VF, especially in the case with VT/VF originating monomorphic PVCs,and ablation might be one of important treatments of idiopathic VT/VF.%目的 探讨射频消融治疗在室性早搏(室早)触发特发性室性心动过速/心室颤动(室速/室颤)中的作用.方法 总结3例由室早触发室速/室颤的治疗经验,1例对室早进行射频消融(RFCA)并植入心律转复除颤器(ICD),另1例经射频消融未完全消除室早而选择植入ICD,第3例经射频消融成功消除室早,未再发室颤.结果 随访2年,3例患者均存活,ICD未再记录到室速/室颤.结论 在室早触发室速/室颤病例中,应分析室早与室速/室颤的相关性,给予个体化治疗,射频消融室早可以消除/减少晕厥和室颤的发作.

  15. Left ventricular layer function in hypertension assessed by myocardial strain rate using novel one-beat real-time three-dimensional speckle tracking echocardiography with high volume rates.

    Science.gov (United States)

    Saeki, Maki; Sato, Noriaki; Kawasaki, Masanori; Tanaka, Ryuhei; Nagaya, Maki; Watanabe, Takatomo; Ono, Koji; Noda, Toshiyuki; Zile, Michael R; Minatoguchi, Shinya

    2015-08-01

    We recently developed novel software to measure phasic strain rate (SR) using automated one-beat real-time three-dimensional speckle tracking echocardiography (3D-STE) with high volume rates. We tested the hypothesis that left ventricular (LV) systolic function and relaxation analyzed by SR with the novel 3D-STE in hypertension (HTN) with hypertrophy may be impaired in the endocardium before there is LV systolic dysfunction. We measured LV longitudinal, radial and circumferential SR in patients with HTN (n=80, 69±7 years) and age-matched normotensive controls (n= 60, 69±10 years) using 3D-STE. HTN patients were divided into four groups according to LV geometry: normal, concentric remodeling, concentric hypertrophy and eccentric hypertrophy. We measured SR during systole as an index of systolic function, SR during isovolumic relaxation (IVR) as an index of relaxation and E/e' as an index of filling pressure. Endocardial SR during systole in HTN with concentric and eccentric hypertrophy decreased compared with that in controls despite no reduction in ejection fraction or epicardial SR. Endocardial radial SR during IVR decreased even in normal geometry, and it was further reduced in concentric remodeling and hypertrophy despite no reduction in epicardial SR. LV phasic SR assessed by 3D-STE with high volume rates is a useful index to detect early decreases in LV systolic function and to predict subclinical LV layer dysfunction in patients with HTN.

  16. EFFECT OF ELECTROACUPUNCTURE ON ACONITINE-INDUCED VENTRICULAR TACHYARRHYTHIMIA

    Institute of Scientific and Technical Information of China (English)

    ZENG Qing; OUYANG Xing-biao; LI Man; LIU Xiao-chun; GUAN Xin-min

    2005-01-01

    Objective:To investigate the effect of electroacupuncture (EA) on aconitine-induced ventricular tachyarrhythmia. Methods: Twenty SD rats ate (300 mg/kg, I.p.) were evenly and anesthetized with chloral hydrrandomly divided into control and EA groups. Ventricular arrhythmia was induced by intravenous infusion of 0.001% aconitine (I.v., 3.5 mg/kg, 0.4 mL/min). EA (4~16 Hz, 1~3 V) was applied to "Neiguan"(内关 PC 6) and "Jianshi"(间使 PC 5) for 30 min. ECG was recorded andanalyzed to determine ventricular premature beat (VPB), ventricular tachycardia (VT) and ventricular fibrillation (VF). Results: EA elevated the dose threshold of aconitine-induced VF (P<0.05), delayed the occurrence of VT and VF (P<0.01), prolonged the survival time and reduced the mortality of rats treated with aconitine (P<0.01). Conclusion: EA can suppress aconitine-induced ventricular tachyarrhythmia.

  17. Regularity of beating of small clusters of embryonic chick ventricular heart-cells: experiment vs. stochastic single-channel population model

    Science.gov (United States)

    Krogh-Madsen, Trine; Kold Taylor, Louise; Skriver, Anne D.; Schaffer, Peter; Guevara, Michael R.

    2017-09-01

    The transmembrane potential is recorded from small isopotential clusters of 2-4 embryonic chick ventricular cells spontaneously generating action potentials. We analyze the cycle-to-cycle fluctuations in the time between successive action potentials (the interbeat interval or IBI). We also convert an existing model of electrical activity in the cluster, which is formulated as a Hodgkin-Huxley-like deterministic system of nonlinear ordinary differential equations describing five individual ionic currents, into a stochastic model consisting of a population of ˜20 000 independently and randomly gating ionic channels, with the randomness being set by a real physical stochastic process (radio static). This stochastic model, implemented using the Clay-DeFelice algorithm, reproduces the fluctuations seen experimentally: e.g., the coefficient of variation (standard deviation/mean) of IBI is 4.3% in the model vs. the 3.9% average value of the 17 clusters studied. The model also replicates all but one of several other quantitative measures of the experimental results, including the power spectrum and correlation integral of the voltage, as well as the histogram, Poincaré plot, serial correlation coefficients, power spectrum, detrended fluctuation analysis, approximate entropy, and sample entropy of IBI. The channel noise from one particular ionic current (IKs), which has channel kinetics that are relatively slow compared to that of the other currents, makes the major contribution to the fluctuations in IBI. Reproduction of the experimental coefficient of variation of IBI by adding a Gaussian white noise-current into the deterministic model necessitates using an unrealistically high noise-current amplitude. Indeed, a major implication of the modelling results is that, given the wide range of time-scales over which the various species of channels open and close, only a cell-specific stochastic model that is formulated taking into consideration the widely different ranges in

  18. Appropriate threshold levels of cardiac beat-to-beat variation in semi-automatic analysis of equine ECG recordings

    DEFF Research Database (Denmark)

    Madsen, Mette Flethøj; Kanters, Jørgen K.; Pedersen, Philip Juul

    2016-01-01

    Background: Although premature beats are a matter of concern in horses, the interpretation of equine ECG recordings is complicated by a lack of standardized analysis criteria and a limited knowledge of the normal beat-to-beat variation of equine cardiac rhythm. The purpose of this study was to de......Background: Although premature beats are a matter of concern in horses, the interpretation of equine ECG recordings is complicated by a lack of standardized analysis criteria and a limited knowledge of the normal beat-to-beat variation of equine cardiac rhythm. The purpose of this study...... was to determine the appropriate threshold levels of maximum acceptable deviation of RR intervals in equine ECG analysis, and to evaluate a novel two-step timing algorithm by quantifying the frequency of arrhythmias in a cohort of healthy adult endurance horses. Results: Beat-to-beat variation differed......, range 1–24). Conclusions: Beat-to-beat variation of equine cardiac rhythm varies according to HR, and threshold levels in equine ECG analysis should be adjusted accordingly. Standardization of the analysis criteria will enable comparisons of studies and follow-up examinations of patients. A small number...

  19. Premature infant

    Science.gov (United States)

    There are many support groups for parents of premature babies. Ask the social worker in the neonatal intensive care unit. ... Prematurity used to be a major cause of infant deaths. Improved ... Prematurity can have long-term effects. Many premature infants ...

  20. A new electrocardiographic algorithm for localizing idiopathic right ventricular outflow tract premature ventricular contraction%右心室流出道室性早搏的定位与导管消融

    Institute of Scientific and Technical Information of China (English)

    张凤祥; 陈明龙; 杨兵; 陈红武; 居维竹; 徐东杰; 曹克将

    2010-01-01

    目的 本文旨在探索判断右心室流出道室性早搏(室早)起源的新流程,以便快速、准确地找到消融靶点.方法 采用非接触三维标测系统对右心室流出道室早进行标测与导管消融,并分析右心室流出道室早体表心电图特征.根据三维标测与导管消融结果,并结合先前报道的室早起源判断流程,设计新的判断室早起源流程.结果 标测与消融结果显示21例患者室早起源于右心室流出道间隔部,其中5例起源于前间隔,4例起源于中间隔,12例起源于后间隔;17例患者室早起源于右心室流出道游离壁,其中5例起源于前游离壁,2例起源于中游离壁,10例起源于后游离壁;1例患者室早起源于希氏束附近.判断室早起源新流程的总阳性预测值(77.3%)较Ito等报道的73.3%、Joshi等报道的73.3%、Dixit等报道的53.8%显著提高(P<0.05).新流程在判断室早具体起源部位较Ito等、Joshi等与Dixit等报道的室早起源部位判断流程有较大的优势,其敏感性、特异性与阳性预测值分别为78.1%,88.9%与84.2%,Joshi等报道的流程分别为32.9%,65.8%与48.1%,Dixit等报道的流程分别为50.7%,63.9%和55.2%(P均<0.05).结论 非接触三维标测系统指导右心室流出道室早消融成功率高,判断室早起源新流程的敏感性、特异性与阳性预测值较先前报道的高,有良好的临床应用价值.%Objective In this study, we explored a new electrocardiographic algorithm for localizing idiopathic right ventricular outflow tract (RVOT)premature ventricular contraction (PVC). Methods A total of 39 patients [23 female, mean age (41.8±13.1) years] with RVOT-PVC enrolled in this study. Ablation was performed under the guidance of 3D non-contact mapping, and a newly proposed ECG algorithm. Results As guided by 3D mapping, the successful ablation was achieved at sites of RVOT septum (n=21), RVOT free wall (n=17) and His region (n=1). Among those PVCs originated from the

  1. Premature ejaculation

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/001524.htm Premature ejaculation To use the sharing features on this page, please enable JavaScript. Premature ejaculation is when a man has an orgasm ...

  2. 右心室间隔部室性早搏/室性心动过速的心电图特征及射频消融治疗%Electrocardiographic characteristics and radiofrequency catheter ablation of premature ventricular complexes/ventricular tachycardia originating from right ventricular septum

    Institute of Scientific and Technical Information of China (English)

    王永光; 林加锋; 李岳春; 季亢挺; 殷日鹏

    2015-01-01

    Objective To observe the curative efficacy and safety of radiofrequency catheter ablation and the electrocardiographic characteristics of idiopathic premature ventricular complexes/ventricular tachycardia(PVC/VT) originating from right ventricular septum.Methods Electrocardiographic characteristics and variation of PVC/VT originating from right ventricular septum were analyzed in 62 patients [32 males,average age of (57.0 ± 18.8) years old] undergoing radiofrequency catheter ablation.Results Forty-nine patients (79.0%) were successfully ablated without related complications.Its electrocardiographic characteristics and change rulewere as follows:①QRS morphology was mainly R in lead Ⅰ;②most was R,a few was r,m or qr in lead aVL;③QS,qs or r in lead aVR;④The position of the origin was positively associated with R wave amplitude in inferior leads,but negatively correlated with the amplitude of S wave;⑤PVC/VT originating from right ventricular outflow tract always manifested as R wave in the inferior leads,while the majority of PVC/VT originating from right ventricular septum showed S wave in at least one or more inferior leads;⑥In addition to PVC/ VT originating from right ventricular septum adjacent to tricuspid annulus and the middle upper septum was rS in lead V1,most PVC/IVT originating from other parts was QS in lead V1,and with the origin point moving down to the middle and apical segments,the amplitude and distribution of precordial R wave becomes less,while QS wave was deeper and distributed more widely.Conclusion Radiofrequency catheter ablation is safe and effective for treating PVC/VT originating from the right ventricular septum,the electrocardiographic characteristics of different origins have certain change rules,grasping these characteristics will be benefit to determine its origin,shorten the operation time.%目的 探讨右心室间隔部起源特发性室性早搏/室性心动过速(PVC/VT)的体表心电图特点及射频消融治

  3. Beat-to-Beat Blood Pressure Monitor

    Science.gov (United States)

    Lee, Yong Jin

    2012-01-01

    This device provides non-invasive beat-to-beat blood pressure measurements and can be worn over the upper arm for prolonged durations. Phase and waveform analyses are performed on filtered proximal and distal photoplethysmographic (PPG) waveforms obtained from the brachial artery. The phase analysis is used primarily for the computation of the mean arterial pressure, while the waveform analysis is used primarily to obtain the pulse pressure. Real-time compliance estimate is used to refine both the mean arterial and pulse pressures to provide the beat-to-beat blood pressure measurement. This wearable physiological monitor can be used to continuously observe the beat-to-beat blood pressure (B3P). It can be used to monitor the effect of prolonged exposures to reduced gravitational environments and the effectiveness of various countermeasures. A number of researchers have used pulse wave velocity (PWV) of blood in the arteries to infer the beat-to-beat blood pressure. There has been documentation of relative success, but a device that is able to provide the required accuracy and repeatability has not yet been developed. It has been demonstrated that an accurate and repeatable blood pressure measurement can be obtained by measuring the phase change (e.g., phase velocity), amplitude change, and distortion of the PPG waveforms along the brachial artery. The approach is based on comparing the full PPG waveform between two points along the artery rather than measuring the time-of-flight. Minimizing the measurement separation and confining the measurement area to a single, well-defined artery allows the waveform to retain the general shape between the two measurement points. This allows signal processing of waveforms to determine the phase and amplitude changes.

  4. 特发性右心室流出道室性心动过速/室性早搏的性别、年龄和临床特点%The gender, age and clinical feature of idiopathic right ventricular outflow tract ventricular tachycardia/premature ventricular complexes

    Institute of Scientific and Technical Information of China (English)

    陈刚; 张澍; 张奎俊; 陈新; 姚焰; 马坚; 楚建民; 方丕华; 贾玉和; 王方正

    2010-01-01

    目的 特发性右心室流出道室性心动过速(室速)/室性早搏(室早)是指不伴有明显器质性心脏病的起源于右心室流出道的室速/室早.对478例特发性右心室流出道室速/室早患者进行系统的回顾性分析,探讨其性别、年龄和临床特点.方法 478例患者,平均年龄(39.8±13.8)岁,在过去的15年里,先后因特发性室速/室早在我院住院治疗,并都接受了心内电生理检查和射频消融术治疗.这478例患者室速/室早的射频消融靶点均位于右心室流出道.结果 在478例患者中,女性288例(60.3%),男性190例(39.7%),女性/男性比为1.52.出现症状的年龄女性为(41.2±12.7)岁,男性为(37.6±15.0)岁(P<0.05),所有患者均有不同程度的心悸症状,478例患者中,67例(14.2%)曾出现过黑矇症状,13例(2.7%)曾经出现晕厥.263例(55%)患者在接受射频消融术前,接受过抗心律失常的药物治疗,药物治疗不成功.结论 特发性右心室流出道室速/室早患者女性较男性多,女性出现临床症状的平均年龄较男性大,对于这一现象的研究有助于揭示这种心律失常的发生机制.所有患者均有不同程度的心慌症状,有的患者甚至出现黑矇、晕厥.因此对于特发性右心室流出道室速/室早应当更加积极地治疗.%Objective The aim of this study was to clarify gender,age and clinical feature of idiopathic right ventricular outflow tract ventricular tachycardia/premature ventricular complexes(ROVT/PVC). Methods We studied 478 patients[mean age(39. 8 ± 13. 8)years]with idiopathic ROVT/PVC who were admitted to our center consecutively in past 15 years. All of them underwent catheter mapping and radiofrequency catheter ablation (RFCA), and the original sites of ventricular tachycardia/premature ventricular complexes were confirmed by catheter mapping and radiofrequency catheter ablation. Results Of 478 patients, 288 patients (60. 3% )were female, 190 patients(39. 7% )were male

  5. Obesity and exercise-induced ectopic ventricular arrhythmias in apparently healthy middle aged adults.

    Science.gov (United States)

    Sabbag, Avi; Sidi, Yechezkel; Kivity, Shaye; Beinart, Roy; Glikson, Michael; Segev, Shlomo; Goldenberg, Ilan; Maor, Elad

    2016-03-01

    Obesity and overweight are strongly associated with cardiovascular morbidity and mortality. However, there are limited data on the association between excess weight and the risk of ectopic ventricular activity. We investigated the association between body mass index (BMI) and the risk for ectopic ventricular activity (defined as multiple ventricular premature beats (≥3), ventricular bigeminy, nonsustained ventricular tachycardia or sustained ventricular tachycardia) during exercise stress testing among 22,516 apparently healthy men and women who attended periodic health screening examinations between the years 2000 and 2014. All subjects had completed maximal exercise stress testing annually according to the Bruce protocol. Subjects were divided at baseline into three groups: normal weight (BMI ≥ 18.5 kg/m(2) andobese (BMI ≥ 30; N = 2,906). The mean age of study subjects was 47 ± 10 years and 72% were men. Kaplan-Meier survival analysis showed that the cumulative probability for the development of exercise-induced ectopic ventricular activity arrhythmias was highest among obese subjects, intermediate among overweight subjects and lowest among subjects with normal weight (3.4%, 2.7% and 2.2% respectively; p obese subjects were 33% more likely to have ectopic ventricular arrhythmias during exercise compared with subjects with normal weight (p = 0.005), and that each 1 kg/m(2) increase in BMI was associated with a significant 4% (p = 0.002) increased adjusted risk for exercise-induced ventricular arrhythmias. Obesity is independently associated with increased likelihood of ectopic ventricular arrhythmia during exercise. © The European Society of Cardiology 2015.

  6. Heart rate turbulence and variability in patients with ventricular arrhythmias

    Directory of Open Access Journals (Sweden)

    Diego Tarricone

    2009-08-01

    Full Text Available Background: To evaluate the changes in autonomic neural control mechanisms before malignant ventricular arrhythmias, we measured heart rate variability (HRV and heart rate turbulence (HRT in patients with ventricular tachycardia or fibrillation (Group I; n=6, non sustained ventricular tachycardia (Group II; n=32, frequent premature ventricular beats (Group III; n=26 and with ICD implantation (Group IV; n=11. Methods: Time domain parameters of HRV and turbulence onset (TO and slope (TS were calculated on 24 hour Holter recordings. Normal values were: SDNN > 70 msec for HRV, TO <0% and TS >2.5 msec/RR-I for HRT. Results: Whereas SDNN was within normal range and similar in all study groups, HRT parameters were significantly different in patients who experienced VT/VF during Holter recording. Abnormal TO and/or TS were present in 100% of Group I patients and only in about 50% of Group II and IV. On the contrary, normal HRT parameters were present in 40-70% of Group II, III and IV patients and none of Group I. Conclusions: These data suggest that HRT analysis is more suitable than HRV to detect those transient alterations in autonomic control mechanisms that are likely to play a major trigger role in the genesis of malignant cardiac arrhythmias. (Heart International 2007; 3: 51-7

  7. The susceptibility of ventricular arrhythmia to aconitine in conscious Lyon hypertensive rats

    Institute of Scientific and Technical Information of China (English)

    Min LI; Jin WANG; He-hui XIE; Fu-ming SHEN; Ding-feng SU

    2007-01-01

    Aim: The present work was designed to investigate the relationship between hemodynamic parameters and the susceptibility of ventricular arrhythmia to aconitine in conscious Lyon hypertensive rats (LH). Methods: Male LH and Lyon low blood pressure rats (LL) were used. After the determination of baroreflex sensitivity (BRS), ventricular arrhythmia was induced by aconitine infusion inconscious rats. Blood pressure (BP) was recorded during the period of infusion. Results: Compared with the LL rats, the LH rats possessed significantly higher BP, blood pressure variability and lower BRS. The threshold of aconitine required for ventricular fibrillation and cardiac arrest in the LH rats were significantly lower than those in the LL rats. It was found that all the hemodynamic parameters studied were not correlated with the tl~eshold of aconitine required for arrhythmia, with the exception of BRS, which was positively related to the threshold of aconitine required for ventricular premature beat. Conclusion: The LH rats possessed greater susceptibility to aconitine-induced ventricular arrhythmias when compared to the LL rats. This greater susceptibility could not be attributed to anyone of the hemodynamic parameters alone studied in the LH rats. It is proposed that various hypertension-associated abnormalities, including the abnormal hemodynamics, may co-contribute to this vulnerability to ventricular arrhythmias.

  8. 频发右心室流出道室性期前收缩对右心室流出道结构影响的研究%Effect of frequent idiopathic ventricular premature contractions from right ventricular outflow tract on structure of right ventricular outflow tract

    Institute of Scientific and Technical Information of China (English)

    孔强; 史力生; 张钰聪; 陈宇嘉; 张帆; 徐东

    2012-01-01

    目的 探讨右心室流出道(RVOT)起源频发室性期前收缩对RVOT结构的影响.方法 选取2009~2011年行射频消融治疗的频发RVOT起源室性期前收缩患者30例,分析其心电图特征、动态心电图、心脏彩色超声结果及术中精确定位,分析室性期前收缩对RVOT结构的影响.结果 射频消融术前RVOT直径为(31.76±3.33)mm,术后6个月为(30.93±2.68)mm(P<0.01);相关性分析显示:RVOT直径与室性期前收缩负荷呈正相关(r=0.484,P<0.05).RVOT间隔部来源室性期前收缩QRS时限为(157.69±18.33) ms,游离壁来源室性期前收缩QRS时限为(179.23±16.05)ms(P<0.01),QRS时限与来源部位相关(r=0.566,P<0.01).室性期前收缩QRS时限与RVOT直径无相关性(r=0.097,P>0.05).结论 RVOT来源室性期前收缩经射频消融治疗后,RVOT直径有减小的趋势,其与室性期前收缩负荷呈正相关,与室性期前收缩形态无相关性.%Objective To investigate the effect of frequent ventricular premature contractions(VPCs) from right ventricular outflow tract (RVOT) on the structure of right ventricular outflow tract. Methods 30 patients with frequent VPCs from RVOT who underwent radiofrequency ablation from 2009 to 2011 were enrolled. The site of origin of VPCs was identified by the characters of ECG according to the stepwise electrocardiographic algorithm and the accurate anatomical location was identified by 3D electroanatomical non-contact mapping. Parameters of haemodynamic were accessed by means of transthoracic echocardiography before and 6 months after intervention. The average daily amount of VPCs was evaluated by Holter and the ECG characters of VPCs were also analyzed. Results Before and 6 months after intervention, the diameter of RVOT was (31. 76 ±3. 33) mm and (30. 93 ±2. 68) mm( P 0. 05). Conclusion The diameter of RVOT decreased after radiofrequency ablation for the patients with VPCs from RVOT and it correlated positively with the average daily

  9. Therapeutic efficiency of catheter ablation in treatment of premature ventricular complexes originating from the right ventricular outflow tract accompanied with left ventricular enlargement: a 5-year follow-up investigation of 30 cases%导管法消融右室流出道室性早搏伴左心室增大30例5年随访观察

    Institute of Scientific and Technical Information of China (English)

    胡立禄; 刘世玉; 雷挺; 高全清; 唐力; 唐成玥; 苏代泉; 帅锋利

    2012-01-01

    目的 探讨导管法消融右室流出道室性早搏伴左心室增大患者的疗效.方法 对30例右室流出道室性早搏伴左心室增大的患者进行导管法射频消融(Radiofrequency cathter ablation,RFCA)治疗.术前常规完成心脏超声检查,成功消融术后5年每年随访超声心动图(ultrasound echocardiography,UCG)及动态心电图(Dynamic Electrocardiogram,DCG,又称Hol-ter).结果 30例患者即刻成功者20例,远期成功8例,无效者2例.术后1年随访20例即刻成功者,UCG结果提示18例患者左室舒张末期内径已在正常值范围内,与自身相比缩小值在3~7 mm以上;随访至第2、3、4、5年,UCG结果无明显变化.另2例患者心脏大小虽未达到正常值范围,但与自身相比较亦有相应缩小.8例远期成功者临床症状也有明显改善.结论 导管法消融治疗右室流出道室早伴左心室增大具有良好临床疗效.%Objective To investigate the therapeutic efficacy of catheter ablation in treatment of patients with premature ven-tricular complexes originating from the right venlricular outftow tract accompanied with left venlricular enlargement Methods The catheler ablalion was performed to 30 patients selected. The rouline cardiac ultrasound examination was carried out before operation. Af-ter surgery, the patients were followed-up for 5 years. During the period of follow-up, echocardiography and dynamic electrocardiogram DCG(Holter)monitoring were performed every year. Results In the 30 patients,20 were acute success,8 were effective,and 2 were in-effeclive. At the first year foltow-up, the UCG resulls showed that 18 of 20 acule success patients presenled a normal left venlricular end-diastolic diameler,and at least reduced 3 ~7 mm compared to pre-operation. During the periods of 2 ~ 5 years foltow-up, no further changes were observed. The heart size of another 2 acule success patients was also reduced although not reach to the normal range. The clinical symptoms of

  10. Improvement of left ventricular hypertrophy and arrhythmias after lanreotide-induced GH and IGF-I decrease in acromegaly. A prospective multi-center study.

    Science.gov (United States)

    Lombardi, G; Colao, A; Marzullo, P; Biondi, B; Palmieri, E; Fazio, S

    2002-12-01

    We report the results of a prospective Italian multi-center study of the effects of lanreotide, a slow-release somatostatin analog, on left ventricular morphology and function and on the prevalence of ventricular arrhythmic events in 19 patients with active, newly diagnosed, uncomplicated acromegaly. Cardiac features were evaluated with Doppler-echocardiography and 24-h Holter ECG monitoring at baseline and after 6 months of lanreotide therapy. Fifteen patients (78.9%) had left ventricular hypertrophy. Lanreotide treatment significantly decreased the left ventricular mass (127.8+/-6.9 vs 140.7+/-7.1 g/m2, paffect systolic function, whereas it increased the Doppler-derived early-to-late mitral flow velocity, (E/A) ratio, of early-to-late trans-mitral flow velocity (1.34+/-0.1 vs 1.09+/-0.06, p=0.001). Stroke volume was slightly but not significantly increased after treatment, whereas systolic BP was significantly higher (134+/-14 vs 129+/-13 mmHg, p50/24 h) occurred in 16.6% of patients and were unaffected by treatment. Differently, ventricular premature beats (>50/24 h) occurred in 33.3% of patients before treatment vs 16.5%, after treatment. In conclusion, lanreotide reduced the left ventricular mass, and improved ventricular filling and ventricular arrhythmic profile.

  11. Effect of Premature Ventricular Contraction From Different Origins onPrognosis in Patients With Chronic Heart Failure%不同起源部位室性早搏对心力衰竭患者预后的影响

    Institute of Scientific and Technical Information of China (English)

    李方; 董守仁; 陈雅丽; 彭欢; 孟婉玉

    2012-01-01

    目的:探讨不同起源部位的室性早搏对心力衰竭(心衰)患者预后的影响.方法:回顾性分析2007-11到2010-12期间在我院住院患者中左心室射血分数≤40%的心衰患者206例,随访1年,8例失访.分析临床各项指标和不同起源部位室性心律失常与心血管死亡间的关系.根据患者是否死亡,将患者分为生存组(n=161)和心血管死亡组(n=37).结果:与生存组比较,心血管死亡组房室传导阻滞(AVB),24小时平均心率,室性早搏(室早)LOWN 分级4A、4B级,室早,非持续性室速发生率;非持续性室速阵数及最快频率,起源于左心室流入道的室早、起源于左心室流入道的非持续性室速均增加,无房室传导阻滞,室早LOWN 分级0、1、2、3级发生率均减少,差异有统计学意义(P<0.05).logistic回归分析表明:收缩压、糖尿病、Ca2+、左心室射血分数、24小时平均心率、室早次数、起源左心室流入道的室早、非持续性室速的阵数是心血管死亡的独立危险因素.结论:室早对判断患者预后有重要价值,起源于左心室流入道室早增加心衰患者心血管死亡率.%Objective:To explore the effect of premature ventricular contraction( PVC )from different origins on prognosis in patients with chronic heart failure( CHF ).Methods:We retrospectively analyzed 206 CHF patients with left ventricular ejection fraction( LVEF ) ≤40% who were treated in our hospital from 2007 to 2010. The patients received 1 year followed-up study for their clinical characteristics, the relationship between cardiovascular mortality and the ventricular arrhythmia from different origins by ambulatory ECG( AECG )param-eters. The patients were divided into two groups as Survival group,n= 161 and Cardiac death group,n = 37. There were 8 patients lost contact.Results: Compared with Survival group, Cardiac death group had increased A-V block, 24h-average heart rate, number of PVC, presence of non-sustained ventricular

  12. Benchmarking ventricular arrhythmias in the mouse--revisiting the 'Lambeth Conventions' 20 years on.

    Science.gov (United States)

    Huggins, Catherine E; Bell, James R; Pepe, Salvatore; Delbridge, Lea M D

    2008-12-01

    The isolated Langendorff-mode perfused heart has become a valuable experimental model, used extensively to examine cardiac function, pathophysiology and pharmacology. For the clinical cardiologist an ECG is often a simple practicality, however in experimental circumstances, particularly with ex vivo murine hearts it is not always possible to obtain an ECG due to experimental recording constraints. However, the mechanical record of ventricular contractile function can be highly informative in relation to electrical state. It is difficult though to achieve consistency in these evaluations of arrhythmia as a validated common reference framework is lacking. In 1988, a group of investigators developed the 'Lambeth Conventions'--a standardised reference for the definition and classification of arrhythmias in animal experimental models of ischaemia, infarction and reperfusion in vivo. Now, two decades later it is timely to revisit the Lambeth Conventions, and to update the guidelines in the context of the marked increase in murine heart study in experimental cardiac pathophysiology. Here we describe an adjunct to the Lambeth Conventions for the reporting of ventricular arrhythmias post-ischaemia in ex vivo mouse hearts when ECG recordings are not employed. Of seven discrete and identifiable patterns of mechanical dysrhythmia observed in reperfusion, five could be classified using conventional ECG terminology: ventricular premature beat, bigeminy, trigeminy, ventricular tachycardia and ventricular fibrillation. Two additional rhythm variations detected from the pressure record are described (potentiated contraction and alternans).

  13. Your Premature Baby

    Science.gov (United States)

    ... birth defects, premature birth and infant mortality. Solving premature birth Featured articles Accomplishments and lessons learned since ... Complications & Loss > Preterm labor & premature birth > Premature babies Premature babies E-mail to a friend Please fill ...

  14. Increased Short-Term Beat-To-Beat Variability of QT Interval in Patients with Acromegaly.

    Directory of Open Access Journals (Sweden)

    Andrea Orosz

    Full Text Available Cardiovascular diseases, including ventricular arrhythmias are responsible for increased mortality in patients with acromegaly. Acromegaly may cause repolarization abnormalities such as QT prolongation and impairment of repolarization reserve enhancing liability to arrhythmia. The aim of this study was to determine the short-term beat-to-beat QT variability in patients with acromegaly. Thirty acromegalic patients (23 women and 7 men, mean age±SD: 55.7±10.4 years were compared with age- and sex-matched volunteers (mean age 51.3±7.6 years. Cardiac repolarization parameters including frequency corrected QT interval, PQ and QRS intervals, duration of terminal part of T waves (Tpeak-Tend and short-term variability of QT interval were evaluated. All acromegalic patients and controls underwent transthoracic echocardiographic examination. Autonomic function was assessed by means of five standard cardiovascular reflex tests. Comparison of the two groups revealed no significant differences in the conventional ECG parameters of repolarization (QT: 401.1±30.6 ms vs 389.3±16.5 ms, corrected QT interval: 430.1±18.6 ms vs 425.6±17.3 ms, QT dispersion: 38.2±13.2 ms vs 36.6±10.2 ms; acromegaly vs control, respectively. However, short-term beat-to-beat QT variability was significantly increased in acromegalic patients (4.23±1.03 ms vs 3.02±0.80, P<0.0001. There were significant differences between the two groups in the echocardiographic dimensions (left ventricular end diastolic diameter: 52.6±5.4 mm vs 48.0±3.9 mm, left ventricular end systolic diameter: 32.3±5.2 mm vs 29.1±4.4 mm, interventricular septum: 11.1±2.2 mm vs 8.8±0.7 mm, posterior wall of left ventricle: 10.8±1.4 mm vs 8.9±0.7 mm, P<0.05, respectively. Short-term beat-to-beat QT variability was elevated in patients with acromegaly in spite of unchanged conventional parameters of ventricular repolarization. This enhanced temporal QT variability may be an early indicator of increased

  15. Value of evaluating diastolic function with the single-beat E/(e’ × s) obtained by dual doppler echocardiograph in coronary heart disease patients with preserved left ventricular systolic function

    Institute of Scientific and Technical Information of China (English)

    汪晶晶

    2014-01-01

    Objective To assess the value of E/(e’×s)in estimating left ventricular diastolic dysfunction in patients with coronary heart disease by dual Doppler echocardiograph.Methods Seventy-seven consecutive coronary heart disease patients with preserved systolic function underwent echocardiographic study were included.The E,e’and s were obtained by the dual Doppler echocardio-

  16. Automatic mode switching of a dual chamber implantable cardioverter-defibrillator induced by a ventricular escape rhythm.

    Science.gov (United States)

    Barold, S Serge; Van Heuverswyn, Frederic; Stroobandt, Roland X

    2013-01-01

    This report describes a form of group beating induced by a St Jude dual chamber ICD which interpreted a ventricular escape rhythm (with retrograde conduction) as premature ventricular complexes (PVC). These pacemaker-defined PVCs activated the atrial pace-PVC algorithm in 2 steps. 1. The postventricular atrial refractory period (PVARP) was terminated upon detecting a retrograde P wave within its unblanked portion, and 2. An atrial stimulus was released 330ms after the end of the PVARP. This response resulted in automatic mode switching because the 330ms interatrial interval was shorter than the atrial tachycardia detection interval. The arrhythmia may be considered to represent an unusual form of pacemaker escape-capture bigeminy.

  17. 单中心流出道室性早搏门诊调查与心电图特征分析%The investigation of the occurrence and characteristics of outpatients with premature ventricular contractions origi-nating from ventricular outflow tract detected by electrocardiogram in a single center

    Institute of Scientific and Technical Information of China (English)

    满艺龙; 杨兵; 汪道武; 陈明龙; 曹克将; 李小荣; 肖峰; 杜为; 刘榜霞; 陈惠平; 王子盾; 郑雅云; 张凤祥

    2014-01-01

    Objective To investigate the occurrence and characteristics of outpatients with premature ventricular con-tractions originating from ventricular outflow tract ( OT-PVC) detected by electrocardiogram ( ECG) in a single center. Methods We collected and analyzed the general characteristics and ECG of outpatients who were diagnosed as OT-PVC from January 01, 2013 to June 30, 2013 in the department of cardiology of the First Affiliated Hospital of Nanjing Medical University. Results ECG of 5545 outpatients were obtained in six months, in whom there were 160 patients (2. 89%) with OT-PVC, including 62 males(38. 75%) and 98 females(61. 25%). Thirty eight patients with OT-PVC (3. 53%) were between 50 and 60 years old and its ratio was higher than the other OT-PVC patients who were less than 50 and more than 60 years old. The ECG in 71 patients (44. 38%) with OT-PVC showed the following abnormalities, including T-wave inversion, ST-segment depression, atrial fibrillation, over-loading of left atrium and premature atrial complex. The average age of patients with ECG abnormalities was elder than that of patients without ECG abnormality [(62. 18±12. 03) vs (46. 37±16. 30) years old, P50~60)岁年龄段患者38例,占3.53%,高于其他年龄段。71例OT鄄PVC患者(44.38%)合并其他类型的心电图异常,依次为T波倒置、ST压低、心房颤动、左房负荷异常及房性早搏。分析发现这71例患者与未合并上述心电图异常的89例OT鄄PVC患者相比平均年龄偏大[(62.2±12.0)岁 vs (46.4±16.3)岁, P<0.05]。结论单中心心血管病门诊就诊人群心电图OT鄄PVC检出率为2.89%,其中(逸50~60)岁人群的OT鄄PVC检出率高于其他年龄段。随着年龄的增长,OT鄄PVC患者更易合并其他类型的心电图异常。

  18. QT dispersion and ventricular arrhythmias in children with primary mitral valve prolapse

    Science.gov (United States)

    İmamoğlu, Ebru Yalın; Eroğlu, Ayşe Güler

    2016-01-01

    Aim: To investigate ventricular arrhythmias in children with primary mitral valve prolapse and to evaluate its relation with QT length, QT dispersion, autonomic function tests and heart rate variability measurements. Material and Methods: Fourty two children with mitral valve prolapse and 32 healthy children were enrolled into the study. Twelve-lead electrocardiograms, autonomic function tests, echocardiography and 24-hour rhythm Holter tests were performed. Electrocardiograms were magnified digitally. The QT length was corrected according to heart rate. The patients were grouped according to the number of premature ventricular contractions and presence of complex ventricular arhythmia in the 24-hour rhythm Holter monitor test. Heart rate variability measurements were calculated automatically from the 24-hour rhythm Holter monitor test. Orthostatic hypotension and resting heart rate were used as autonomic function tests. Results: The mean age was 13.9±3.3 years in the patient group and 14.6±3.1 years in the control group (p>0.05). Thirty four of the patients (81%) were female and eight (19%) were male. Twenty five of the control subjects (78%) were female and seven (22%) were male. The QT dispersion and heart rate corrected QT interval were found to be significantly increased in the children with primary mitral valve prolapse when compared with the control group (56±16 ms vs. 43±11 ms, p=0.001; 426±25 ms vs. 407±26 ms, p=0.002, respectively). In 24-hour rhythm Holter monitor tests, ventricular arrhythmias were found in 21 out of 42 patients (50%) and 6 out of 32 control subjects (18.8%) (p=0.006). QT dispersion was found to be significantly increased in patients with premature ventricular contractions ≥ 10/day and/or complex ventricular arrhythmias compared to the control group without ventricular premature beats (p=0.002). There was no significant difference in autonomic function tests and heart rate variability measurements between the patient and control

  19. Strong modulation of ectopic focus as a mechanism of repetitive interpolated ventricular bigeminy with heart rate doubling.

    Science.gov (United States)

    Takayanagi, Kan; Nakahara, Shiro; Toratani, Noritaka; Chida, Ryuji; Kobayashi, Sayuki; Sakai, Yoshihiko; Takeuchi, Akihiro; Ikeda, Noriaki

    2013-10-01

    Repetitive interpolated ventricular bigeminy (RIVB) can introduce a doubling of the ventricular rate. To clarify the mechanism of RIVB, we hypothesized that it was introduced by a strong modulation of the ventricular automatic focus. RIVB, defined as more than 7 bigeminy events, was detected by instantaneous heart rate and bigeminy interval (BI) tachograms in 1450 successive patients with frequent ventricular premature contractions (≥3000 per day). Postextrasystolic interval bigeminy interval curves were plotted to determine the degree of modulation. Mean sinus cycle length bigeminy interval curves were plotted for selection. RIVB was simulated by using a computer-based parasystole model. RIVB was observed in 7 patients (age 60 ± 16 years; 2 men and 5 women) with a heart rate of 58.2 ± 6.5 beats/min during a rest period both during the day and at night. The tachograms disclosed the onset of the RIVB with a doubled ventricular rate to 112.3 ± 8.5 beats/min. On the postextrasystolic interval bigeminy interval curves, compensatory bigeminy and interpolated bigeminy constituted overlapping regression lines with slopes close to 1.00 and RIVB was located in the lower left portion. RIVB lasting for up to 3 hours was quickly detected by mean sinus cycle length bigeminy interval curve. The PQ interval immediately after RIVB was prolonged in comparison with baseline (0.18 ± 0.02 to 0.21 ± 0.02 seconds; P heart rate. Our findings support the hypothesis that RIVB was introduced by strongly modulated ventricular pacemaker accelerated by an intervening normal QRS. © 2013 Heart Rhythm Society. All rights reserved.

  20. Wearable Beat to Beat Blood Pressure Monitor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A key component of NASA's human exploration programs is a system that monitors the health of the crew during space missions. The wearable beat-to-beat blood pressure...

  1. Clinical Analysis of Emergency Application of Amiodarone in Acute Myocardial Infarction Patients with Malignant Ventricular Arrhythmia%急性心肌梗死伴恶性室性心律失常急诊胺碘酮的应用

    Institute of Scientific and Technical Information of China (English)

    杨华; 王月权; 李宁

    2015-01-01

    39 cases of acute myocardial infarction (AMI) with malignant ventricular ar hythmia, frequent ventricular premature beat (hereinafter refer ed to as premature ventricular) in 16 cases, 17 cases of ventricular tachycardia (vt), ventricular fibril ation (ventricular fibril ation) 6 cases. Give room early and ventricular tachycardia patients after intravenous amiodarone, rectified ventricular ar hythmia, ventricular fibril ation, 6 cases of patients with first give cardioerter, success in 4 cases, 2 cases after fails to give amiodarone, defibril ation success again. 38 cases of successful rescue, 1 case died of brain death. Rescue winners are transfer ed to medical ward for treatment.%39例急性心肌梗死(AMI)伴恶性室性心律失常,频发室性早搏(简称室早)16例,室性心动过速(简称室速)17例,心室颤动(简称室颤)6例。对室早及室速的患者给予静脉胺碘酮后,室性心律失常得以纠正,对室颤6例患者先给予电复律,4例除颤成功,2例不成功者给予胺碘酮后,再次除颤成功。抢救成功38例,1例死于脑死亡。抢救成功者均转入内科病房治疗。

  2. Efficacy of radiofrequency catheter ablation reversing frequent premature ventricular complexes%射频消融术对频发室性早搏患者左心室功能的影响

    Institute of Scientific and Technical Information of China (English)

    聂建明; 韩智红; 张烨; 王云龙; 汪烨; 李腾飞; 任学军

    2013-01-01

    目的 探讨射频消融术能否纠正左心室功能失调.方法 将符合入组标准的患者49例分成射频消融组(35例)和对照组(14例).射频消融组患者行射频消融治疗,对照组患者接受药物干预.患者均随访3~6个月,评估2组患者室性期前收缩负荷(PVC)、左心室射血分数(LVEF)、左心室舒张末期内径(LVEDD)及左心室收缩末期内径(LVESD)等情况.结果 治疗前射频消融组与对照组PVC、LVEF、LVEDD、LVESD差异均无统计学意义[(24±11)%比(21±7)%;(63±9)%比(60±6)%;(50±4) mm比(49±5)mm; (32±5)mm比(34 ±3) mm;均P>0.05].治疗后射频消融组PVC明显减低[(8±11)%比(24±11)%,t =6.149,P<0.01],LVEF明显增高[(68±5)%比(63±9)%,t=3.426,P<0.01],LVEDD明显减小[(48±3)mm比(50±4)mm,t=3.539,P<0.01],LVESD明显减小[(3l±3)mm比(32±5)mm,t=2.665,P <0.05].对照组治疗后PVC增高[(22±5)%比(21±7)%,t=3.180,P<0.05],LVEF减低[(59±5)%比(60±6)%,t=2.754,P<0.05],LVEDD增加[(50±5)mm比(49 ±5)mm,t =5.551,P<0.01],LVESD增加[(35 ±3)mm比(34±3)mm,t=2.599,P<0.05].射频消融组治疗后PVC、LVEF、LVESD与对照组治疗后比较差异均有统计学意义(均P<0.01).结论 频发室性早搏的患者更易发生左心室扩大和收缩功能失调.对药物治疗不满意的频发室性早搏患者通过射频导管消融治疗可以获得满意的疗效.对有适应证者应尽早行射频消融术根治.%Objective To explore whether radiofrequency catheter ablation can reverse left ventricular dysfunction.Methods Totally 35 patients for radiofrequency catheter ablation (RFCA) and 14 patients who took antiarrhythmic drugs but did not accept radiofrequency catheter ablation were enrolled.All patients were evaluated at baseline and 3-6 months followed up in terms of premature ventricular complexes (PVC),left ventricular ejection fraction (LVEF),left ventricular end-diastolic dimension (LVEDD) and left ventricular end systolic

  3. Off beat: pluralizing rhythm

    NARCIS (Netherlands)

    Hoogstad, J.H.; Stougaard Pedersen, B.

    2013-01-01

    Off Beat: Pluralizing Rhythm draws attention to rhythm as a tool for analyzing various cultural objects. In fields as diverse as music, culture, nature, and economy, rhythm can be seen as a phenomenon that both connects and divides. It suggests a certain measure with which people, practices, and cul

  4. Ablação com radiofreqüência de extra-sístoles da via de saída do ventrículo direito Radiofrequency catheter ablation of premature ventricular contractions originating in the right ventricular outflow tract

    Directory of Open Access Journals (Sweden)

    Francisco C. C. Darrieux

    2007-03-01

    Full Text Available OBJETIVOS: Avaliar se a ablação com radiofreqüência é um procedimento eficiente para o tratamento das extra-sístoles da via de saída do ventrículo direito (EVSVD, e se resulta em melhora dos sintomas. MÉTODOS: Estudo prospectivo, com 30 pacientes consecutivos (idade média de 40±13 anos, 25 do sexo feminino, sem cardiopatia estrutural aparente, com EVSVD, muito freqüentes (densidade média de 1.263±593/h, sintomáticos por mais de 1 ano (média =74 meses e refratários aos fármacos antiarrítmicos (3±1,7, incluindo os beta-bloqueadores, que foram submetidos à ablação com radiofreqüência. RESULTADOS: Após o primeiro procedimento, houve 23 sucessos iniciais (76,6% e 7 iniciais insucessos (23,4%. Quatro pacientes tiveram recorrências, sendo que dois desses não se submeteram ao segundo procedimento. O segundo procedimento foi realizado em 9 pacientes (7 insucessos iniciais e 2 recorrências, e o sucesso ocorreu em 5 pacientes adicionais, sendo 1 caso por acesso epicárdico. A taxa de sucesso final foi de 80% (24/30, e nenhuma complicação maior ocorreu. Após um seguimento médio de 14±6 meses, no grupo de sucesso final houve uma redução de mais de 90% na densidade das extra-sístoles(24/24; pOBJECTIVES: To evaluate if radiofrequency catheter ablation is an effective procedure for the treatment of right ventricular outflow tract premature ventricular contractions (RVOT-PVC and ascertain if it results in an improvement of symptoms. METHODS: A prospective study with 30 consecutive patients (mean age 40 ± 13 years, 25 females, with no apparent structural cardiopathy, with very frequent (mean density of 1,263 ± 593/h RVOT-PVC, symptomatic for more than one year (mean = 74 months and resistant to antiarrhythmic drugs (3 ± 1.7, including beta-blockers, who underwent radiofrequency catheter ablation. RESULTS: After the first procedure, there were 23 initial successful cases (76.6% and 7 initial failures (23.4%. Four patients

  5. Osteopenia - premature infants

    Science.gov (United States)

    Neonatal rickets; Brittle bones - premature infants; Weak bones - premature infants; Osteopenia of prematurity ... the baby. This helps the baby grow. A premature infant may not receive the proper amount of ...

  6. Quinidine elicits proarrhythmic changes in ventricular repolarization and refractoriness in guinea-pig.

    Science.gov (United States)

    Osadchii, Oleg E

    2013-04-01

    Quinidine is a class Ia Na(+) channel blocker that prolongs cardiac repolarization owing to the inhibition of I(Kr), the rapid component of the delayed rectifier current. Although quinidine may induce proarrhythmia, the contributing mechanisms remain incompletely understood. This study examined whether quinidine may set proarrhythmic substrate by inducing spatiotemporal abnormalities in repolarization and refractoriness. The monophasic action potential duration (APD), effective refractory periods (ERPs), and volume-conducted electrocardiograms (ECGs) were assessed in perfused guinea-pig hearts. Quinidine was found to produce the reverse rate-dependent prolongation of ventricular repolarization, which contributed to increased steepness of APD restitution. Throughout the epicardium, quinidine elicited a greater APD increase in the left ventricular chamber compared with the right ventricle, thereby enhancing spatial repolarization heterogeneities. Quinidine prolonged APD to a greater extent than ERP, thus extending the vulnerable window for ventricular re-excitation. This change was attributed to increased triangulation of epicardial action potential because of greater APD lengthening at 90% repolarization than at 30% repolarization. Over the transmural plane, quinidine evoked a greater ERP prolongation at endocardium than epicardium and increased dispersion of refractoriness. Premature ectopic beats and monomorphic ventricular tachycardia were observed in 50% of quinidine-treated heart preparations. In summary, abnormal changes in repolarization and refractoriness contribute greatly to proarrhythmic substrate upon quinidine infusion.

  7. Increased Short-Term Beat-To-Beat Variability of QT Interval in Patients with Acromegaly.

    Science.gov (United States)

    Orosz, Andrea; Csajbók, Éva; Czékus, Csilla; Gavallér, Henriette; Magony, Sándor; Valkusz, Zsuzsanna; Várkonyi, Tamás T; Nemes, Attila; Baczkó, István; Forster, Tamás; Wittmann, Tibor; Papp, Julius Gy; Varró, András; Lengyel, Csaba

    2015-01-01

    Cardiovascular diseases, including ventricular arrhythmias are responsible for increased mortality in patients with acromegaly. Acromegaly may cause repolarization abnormalities such as QT prolongation and impairment of repolarization reserve enhancing liability to arrhythmia. The aim of this study was to determine the short-term beat-to-beat QT variability in patients with acromegaly. Thirty acromegalic patients (23 women and 7 men, mean age±SD: 55.7±10.4 years) were compared with age- and sex-matched volunteers (mean age 51.3±7.6 years). Cardiac repolarization parameters including frequency corrected QT interval, PQ and QRS intervals, duration of terminal part of T waves (Tpeak-Tend) and short-term variability of QT interval were evaluated. All acromegalic patients and controls underwent transthoracic echocardiographic examination. Autonomic function was assessed by means of five standard cardiovascular reflex tests. Comparison of the two groups revealed no significant differences in the conventional ECG parameters of repolarization (QT: 401.1±30.6 ms vs 389.3±16.5 ms, corrected QT interval: 430.1±18.6 ms vs 425.6±17.3 ms, QT dispersion: 38.2±13.2 ms vs 36.6±10.2 ms; acromegaly vs control, respectively). However, short-term beat-to-beat QT variability was significantly increased in acromegalic patients (4.23±1.03 ms vs 3.02±0.80, Pacromegaly in spite of unchanged conventional parameters of ventricular repolarization. This enhanced temporal QT variability may be an early indicator of increased liability to arrhythmia.

  8. Increased Short-Term Beat-To-Beat Variability of QT Interval in Patients with Acromegaly

    Science.gov (United States)

    Orosz, Andrea; Csajbók, Éva; Czékus, Csilla; Gavallér, Henriette; Magony, Sándor; Valkusz, Zsuzsanna; Várkonyi, Tamás T.; Nemes, Attila; Baczkó, István; Forster, Tamás; Wittmann, Tibor; Papp, Julius Gy.; Varró, András; Lengyel, Csaba

    2015-01-01

    Cardiovascular diseases, including ventricular arrhythmias are responsible for increased mortality in patients with acromegaly. Acromegaly may cause repolarization abnormalities such as QT prolongation and impairment of repolarization reserve enhancing liability to arrhythmia. The aim of this study was to determine the short-term beat-to-beat QT variability in patients with acromegaly. Thirty acromegalic patients (23 women and 7 men, mean age±SD: 55.7±10.4 years) were compared with age- and sex-matched volunteers (mean age 51.3±7.6 years). Cardiac repolarization parameters including frequency corrected QT interval, PQ and QRS intervals, duration of terminal part of T waves (Tpeak-Tend) and short-term variability of QT interval were evaluated. All acromegalic patients and controls underwent transthoracic echocardiographic examination. Autonomic function was assessed by means of five standard cardiovascular reflex tests. Comparison of the two groups revealed no significant differences in the conventional ECG parameters of repolarization (QT: 401.1±30.6 ms vs 389.3±16.5 ms, corrected QT interval: 430.1±18.6 ms vs 425.6±17.3 ms, QT dispersion: 38.2±13.2 ms vs 36.6±10.2 ms; acromegaly vs control, respectively). However, short-term beat-to-beat QT variability was significantly increased in acromegalic patients (4.23±1.03 ms vs 3.02±0.80, Pacromegaly in spite of unchanged conventional parameters of ventricular repolarization. This enhanced temporal QT variability may be an early indicator of increased liability to arrhythmia. PMID:25915951

  9. Premature delivery

    Directory of Open Access Journals (Sweden)

    Bernardita Donoso Bernales

    2012-09-01

    Full Text Available Preterm delivery is the single most important cause of perinatal morbidity and mortality. In Chile, preterm births have increased in the past decade, although neonatal morbidity and mortality attributable to it shows a downward trend, thanks to improvements in neonatal care of premature babies, rather than the success of obstetric preventive and therapeutic strategies. This article describes clinical entities, disease processes and conditions that constitute predisposing factors of preterm birth, as well as an outline for the prevention and clinical management of women at risk of preterm birth.

  10. 室早 TpR 指数与特发性流出道室早症状的关系%Relationship between TpR index and symptoms of idiopathic outflow tract premature ventricu-lar contraction

    Institute of Scientific and Technical Information of China (English)

    张奇; 赵春梅; 王德国; 杨琴; 李小荣; 张凤祥; 曹克将

    2016-01-01

    Objective To analyze the relationship between arrhythmic symptoms of the patients with outflow tract premature ventricular contraction (PVC)and characteristics of surface electrocardi-ogram(ECG),and to explore its clinical significance.Methods According to the existence of PVC-related arrhythmic symptoms,97 outflow tract PVC patients were divided into two group:symptomatic group(60 cases)and asymptomatic group(37 cases).The examination of echocardio-graphy and standard 1 2 lead surface ECG were performed on all the patients.The measured parame-ters included PVC burden,the width of PVC complex,coupling interval,index of PVC coupling in-terval(PVC coupling interval ÷sinus RR cycle ×1 00%),TpR interval of PVC(the duration from si-nus T peak before PVC to the starting point of PVC)and TpR index of PVC(TpR interval of PVC ÷sinus TpR interval ×1 00%).The relationship between the above measured parameters and arrhyth-mic symptoms was analyzed.Results In the symptomatic group,the index of PVC coupling inter-val,TpR interval of PVC and TpR index of PVC were significantly higher than those in the asympto-matic group(P <0.05).However,there was no statistically significant difference of PVC burden, origin of PVC or other ECG parameters between the two groups.Spearman correlation analysis showed that PVC-related symptoms were significantly positively correlated with the index of PVC coupling interval(r =0.324,P <0.05),TpR interval of PVC(r =0.272,P <0.05)and TpR in-dex of PVC(r =0.457,P <0.05).Conclusion PVC-related symptoms are associated with higher index of PVC coupling interval and TpR index for patients with outflow tract PVC.Those symptoms are related to the delayed emergence of PVC,which is helpful in the control of PVC clinically.%目的:分析流出道室早(premature ventricular contraction,PVC)患者心律失常症状与体表心电图特征的关系及其临床意义。方法将97例流出道室早患者根据有无心律失常症

  11. Epicardial and endocardial mapping determine most successful site of ablation for ventricular tachyarrhythmias originating from left ventricular summit.

    Science.gov (United States)

    Iijima, Kenichi; Chinushi, Masaomi; Furushima, Hiroshi; Aizawa, Yoshifusa

    2012-06-01

    A 34-year-old woman presented with idiopathic premature ventricular complex (PVC) and ventricular tachycardia (VT) originating from the area called the left ventricular summit. Radiofrequency (RF) application both through the coronary sinus and to the epicardial surface transiently suppressed the VT/PVC. Radiofrequency with sufficient energy was only applicable from the endocardial site, and the VT/PVC was successfully eliminated.

  12. Sudden cardiac death in dogs with remodeled hearts is associated with larger beat-to-beat variability of repolarization

    DEFF Research Database (Denmark)

    Thomsen, Morten Bækgaard; Truin, Michiel; van Opstal, Jurren M

    2005-01-01

    Increased proarrhythmia in dogs with chronic AV block (AVB) has been explained by ventricular remodeling causing a decrease in repolarization reserve. Beat-to-beat variability of repolarization (BVR) has been suggested to reflect repolarization reserve, in which high variability represents...... diminished reserve and larger propensity for repolarization-dependent ventricular arrhythmia. A subset of chronic AVB dogs (10%) suffers sudden cardiac death (SCD). With the assumption that repolarization defects constitute a potentially lethal proarrhythmic substrate, we hypothesized that BVR in SCD dogs...... are larger than in matched control chronic AVB dogs. From a population of 200 chronic AVB dogs, initially two groups were chosen retrospectively: 8 dogs that died suddenly (SCD) and 8 control dogs. Control dogs had a longer lifespan after AVB (10 to 18 weeks) than SCD dogs (5 to 10 weeks). All dogs had...

  13. 中医药治疗冠心病室性早搏的系统评价%Systematic Review of Traditional Chinese Medicine for Ventricular Premature Complexes in Coronary Artery Disease

    Institute of Scientific and Technical Information of China (English)

    张萍; 李博; 徐凤芹; 马晓昌; 陈可冀

    2012-01-01

    目的 评价中医药治疗冠心病室性早搏的有效性及安全性.方法 计算机检索了PubMed、Cochrane图书馆临床试验注册数据库,中国生物医学文献数据库(Web版)、中文生物医学期刊数据库(Web版)CMCC、VIP中文科技期刊数据库(Web版)、CNKI中国期刊全文数据库(Web版)、万方数据库,筛选出中医药治疗冠心病室性早搏的随机对照试验(RCT)或半随机对照试验.用Jadad评分对纳入研究的质量进行评价,RevMan5.1.4软件进行Meta分析.结果 共收集中医药治疗冠心病室性早搏文献486篇,经过初筛和严格评价,纳入研究14个,共1 560例,治疗组901例,对照组659例.纳入研究的Jadad评分≥3分.对14项研究的临床疗效有效率合并效应量的检验,PP分析结果:RR(random)=1.25,95%CI[1.13,1.37],有统计学意义(P<0.000 1);ITT分析结果:RR(fixed)=1.26,95%CI[1.17,1.36],有统计学意义(P<0.000 1).结论 根据当前研究提示,中医药治疗冠心病室性早搏可能是有效的,但尚需更多高质量研究以增加证据的强度.%Objective To assess the effectiveness and safety of traditional Chinese medicine(TCM) in the treatment of ventricular premature complexes (VPC) in coronary artery disease(CAD). Methods We searched the literature associated with randomized controlled trials(RCT) or quasi - RCT of TCM in treating CAD patients with VPC from PubMed (update to Feb 2011), Chinese Biology Medicine disc For Internet (CBM Web) (update to Feb 2011), Chinese Medical Current Content (CMCC) (update to Feb 2011) , VIP Chinese science and Technology Periodical Database (update to Feb 2011) ,CNKI China Journal Full - text Database (update to Feb 2011), and Wan Fang Database (update to Feb 2011). Quality of them was evaluated by the method - Jadad Score, and statistical analysis was performed using the Cochrane Collaboration's Rev Man 5. 1. 4 software. Results 14 trials involving 1 560 VPC patients (901 patients in the treated group and 659

  14. Resonant Bloch-wave beatings.

    Science.gov (United States)

    Kartashov, Yaroslav V; Vysloukh, Victor A; Torner, Lluis

    2014-07-01

    We introduce Bloch-wave beatings in arrays of multimode periodically bent waveguides with a transverse refractive index gradient. The new phenomenon manifests itself in the periodic drastic increase of the amplitude of the Bloch oscillations that accompanies resonant conversion of modes guided by the individual waveguides. The Bloch-wave beatings are found to be most pronounced when the length of the resonant mode conversion substantially exceeds the longitudinal period of the Bloch oscillations. The beating frequency decreases when the amplitude of waveguide bending decreases, while the beating amplitude is restricted by the amplitude of the Bloch oscillations that emerge from the second allowed band of the Floquet-Bloch lattice spectrum.

  15. Resonant Bloch-wave beatings

    CERN Document Server

    Kartashov, Yaroslav V; Torner, Lluis

    2014-01-01

    We introduce Bloch-wave beatings in arrays of multimode periodically bent waveguides with a transverse refractive index gradient. The new phenomenon manifests itself in the periodic drastic increase of the amplitude of the Bloch oscillations that accompanies resonant conversion of modes guided by the individual waveguides. The Bloch-wave beatings are found to be most pronounced when the length of the resonant mode conversion substantially exceeds the longitudinal period of the Bloch oscillations. The beating frequency decreases when the amplitude of waveguide bending decreases, while the beating amplitude is restricted by the amplitude of the Bloch oscillations that emerge from the second allowed band of the Floquet-Bloch lattice spectrum.

  16. Stochastic spontaneous calcium release events and sodium channelopathies promote ventricular arrhythmias

    Science.gov (United States)

    Campos, Fernando O.; Shiferaw, Yohannes; Vigmond, Edward J.; Plank, Gernot

    2017-09-01

    Premature ventricular complexes (PVCs), the first initiating beats of a variety of cardiac arrhythmias, have been associated with spontaneous calcium release (SCR) events at the cell level. However, the mechanisms underlying the degeneration of such PVCs into arrhythmias are not fully understood. The objective of this study was to investigate the conditions under which SCR-mediated PVCs can lead to ventricular arrhythmias. In particular, we sought to determine whether sodium (Na+) current loss-of-function in the structurally normal ventricles provides a substrate for unidirectional conduction block and reentry initiated by SCR-mediated PVCs. To achieve this goal, a stochastic model of SCR was incorporated into an anatomically accurate compute model of the rabbit ventricles with the His-Purkinje system (HPS). Simulations with reduced Na+ current due to a negative-shift in the steady-state channel inactivation showed that SCR-mediated delayed afterdepolarizations led to PVC formation in the HPS, where the electrotonic load was lower, conduction block, and reentry in the 3D myocardium. Moreover, arrhythmia initiation was only possible when intrinsic electrophysiological heterogeneity in action potential within the ventricles was present. In conclusion, while benign in healthy individuals SCR-mediated PVCs can lead to life-threatening ventricular arrhythmias when combined with Na+ channelopathies.

  17. Premature ejaculation

    Directory of Open Access Journals (Sweden)

    Chris G McMahon

    2007-01-01

    Full Text Available Premature ejaculation (PE is a common male sexual disorder. Recent normative data suggests that men with an intravaginal ejaculatory latency time (IELT of less than 1 minute have "definite" PE, while men with IELTs between 1 and 1.5 minutes have "probable" PE. Although there is insufficient empirical evidence to identify the etiology of PE, there is limited correlational evidence to suggest that men with PE have high levels of sexual anxiety and inherited altered sensitivity of central 5-HT (5-hydroxytryptamine, serotonin receptors. Pharmacological modulation of the ejaculatory threshold using off-label daily or on-demand selective serotonin re-uptake inhibitors is well tolerated and offers patients a high likelihood of achieving improved ejaculatory control within a few days of initiating treatment, consequential improvements in sexual desire and other sexual domains. Investigational drugs such as the ejaculo-selective serotonin transport inhibitor, dapoxetine represent a major development in sexual medicine. These drugs offer patients the convenience of on-demand dosing, significant improvements in IELT, ejaculatory control and sexual satisfaction with minimal adverse effects.

  18. Premature ejaculation.

    Science.gov (United States)

    McMahon, Chris G

    2007-04-01

    Premature ejaculation (PE) is a common male sexual disorder. Recent normative data suggests that men with an intravaginal ejaculatory latency time (IELT) of less than 1 minute have "definite" PE, while men with IELTs between 1 and 1.5 minutes have "probable" PE. Although there is insufficient empirical evidence to identify the etiology of PE, there is limited correlational evidence to suggest that men with PE have high levels of sexual anxiety and inherited altered sensitivity of central 5-HT (5-hydroxytryptamine, serotonin) receptors. Pharmacological modulation of the ejaculatory threshold using off-label daily or on-demand selective serotonin re-uptake inhibitors is well tolerated and offers patients a high likelihood of achieving improved ejaculatory control within a few days of initiating treatment, consequential improvements in sexual desire and other sexual domains. Investigational drugs such as the ejaculo-selective serotonin transport inhibitor, dapoxetine represent a major development in sexual medicine. These drugs offer patients the convenience of on-demand dosing, significant improvements in IELT, ejaculatory control and sexual satisfaction with minimal adverse effects.

  19. Vulnerability to ventricular fibrillation

    Science.gov (United States)

    Janse, Michiel J.

    1998-03-01

    One of the factors that favors the development of ventricular fibrillation is an increase in the dispersion of refractoriness. Experiments will be described in which an increase in dispersion in the recovery of excitability was determined during brief episodes of enhanced sympathetic nerve activity, known to increase the risk of fibrillation. Whereas in the normal heart ventricular fibrillation can be induced by a strong electrical shock, a premature stimulus of moderate intensity only induces fibrillation in the presence of regional ischemia, which greatly increases the dispersion of refractoriness. One factor that is of importance for the transition of reentrant ventricular tachycardia to ventricular fibrillation during acute regional ischemia is the subendocardial Purkinje system. After selective destruction of the Purkinje network by lugol, reentrant tachycardias still develop in the ischemic region, but they do not degenerate into fibrillation. Finally, attempts were made to determine the minimal mass of thin ventricular myocardium required to sustain fibrillation induced by burst pacing. This was done by freezing of subendocardial and midmural layers. The rim of surviving epicardial muscle had to be larger than 20 g. Extracellular electrograms during fibrillation in both the intact and the "frozen" left ventricle were indistinguishable, but activation patterns were markedly different. In the intact ventricle epicardial activation was compatible with multiple wavelet reentry, in the "frozen" heart a single, or at most two wandering reentrant waves were seen.

  20. Masses for Galactic Beat Cepheids

    Science.gov (United States)

    D'Cruz, Noella L.; Morgan, Siobahn M.; Böhm-Vitense, Erika

    2000-08-01

    Accurate mass determinations for Cepheids may be used to determine the degree of excess mixing in the interiors of their main-sequence progenitors: the larger the excess mixing, the larger the luminosity of the Cepheid of a given mass, or the smaller the mass of a Cepheid with given luminosity. Dynamical masses determined recently for a few Cepheid binaries indicate excess mixing somewhat stronger than that corresponding to the convective overshoot models by Schaller et al. Beat Cepheids can be used similarly to test main-sequence mixing in stellar interiors. The period ratios for beat Cepheids depend on luminosity, Teff, heavy element abundance, and mass. By comparing pulsational models and the observationally derived luminosity, Teff, metallicities, and period ratios it is possible to obtain masses for these stars, the so-called beat masses. With the old opacities masses much smaller than the evolutionary masses were obtained. With the new OPAL opacities a beat mass close to the dynamical mass was obtained for the binary beat Cepheid Y Carinae, showing that it is now possible to obtain reliable beat masses. In this paper, we determine beat masses for seven Galactic beat Cepheids for which photometric and spectroscopic data are available. We find an average mass around 4.2+/-0.3 Msolar for these stars, though the actual error limits for each star may be larger mainly because of uncertainties in E(B-V) and the heavy element abundances. (As derived spectroscopically, beat Cepheids are in general metal-poor, with -0.4relation between the derived beat masses and the luminosities again indicates excess mixing that is somewhat larger than that corresponding to the models by Schaller et al.

  1. Beat to beat variability in cardiovascular variables: noise or music?

    Science.gov (United States)

    Appel, M. L.; Berger, R. D.; Saul, J. P.; Smith, J. M.; Cohen, R. J.

    1989-01-01

    Cardiovascular variables such as heart rate, arterial blood pressure, stroke volume and the shape of electrocardiographic complexes all fluctuate on a beat to beat basis. These fluctuations have traditionally been ignored or, at best, treated as noise to be averaged out. The variability in cardiovascular signals reflects the homeodynamic interplay between perturbations to cardiovascular function and the dynamic response of the cardiovascular regulatory systems. Modern signal processing techniques provide a means of analyzing beat to beat fluctuations in cardiovascular signals, so as to permit a quantitative, noninvasive or minimally invasive method of assessing closed loop hemodynamic regulation and cardiac electrical stability. This method promises to provide a new approach to the clinical diagnosis and management of alterations in cardiovascular regulation and stability.

  2. Cardiac overexpression of constitutively active Galpha q causes angiotensin II type1 receptor activation, leading to progressive heart failure and ventricular arrhythmias in transgenic mice.

    Directory of Open Access Journals (Sweden)

    Naoko Matsushita

    Full Text Available Transgenic mice with transient cardiac expression of constitutively active Galpha q (Gαq-TG exhibt progressive heart failure and ventricular arrhythmias after the initiating stimulus of transfected constitutively active Gαq becomes undetectable. However, the mechanisms are still unknown. We examined the effects of chronic administration of olmesartan on heart failure and ventricular arrhythmia in Gαq-TG mice.Olmesartan (1 mg/kg/day or vehicle was chronically administered to Gαq-TG from 6 to 32 weeks of age, and all experiments were performed in mice at the age of 32 weeks. Chronic olmesartan administration prevented the severe reduction of left ventricular fractional shortening, and inhibited ventricular interstitial fibrosis and ventricular myocyte hypertrophy in Gαq-TG. Electrocardiogram demonstrated that premature ventricular contraction (PVC was frequently (more than 20 beats/min observed in 9 of 10 vehicle-treated Gαq-TG but in none of 10 olmesartan-treated Gαq-TG. The collected QT interval and monophasic action potential duration in the left ventricle were significantly shorter in olmesartan-treated Gαq-TG than in vehicle-treated Gαq-TG. CTGF, collagen type 1, ANP, BNP, and β-MHC gene expression was increased and olmesartan significantly decreased the expression of these genes in Gαq-TG mouse ventricles. The expression of canonical transient receptor potential (TRPC 3 and 6 channel and angiotensin converting enzyme (ACE proteins but not angiotensin II type 1 (AT1 receptor was increased in Gαq-TG ventricles compared with NTG mouse ventricles. Olmesartan significantly decreased TRPC6 and tended to decrease ACE expressions in Gαq-TG. Moreover, it increased AT1 receptor in Gαq-TG.These findings suggest that angiotensin II type 1 receptor activation plays an important role in the development of heart failure and ventricular arrhythmia in Gαq-TG mouse model of heart failure.

  3. Ventricular assist device

    Science.gov (United States)

    VAD; RVAD; LVAD; BVAD; Right ventricular assist device; Left ventricular assist device; Biventricular assist device; Heart pump; Left ventricular assist system; LVAS; Implantable ventricular assist device

  4. Intra-beat Scaling Properties of Cardiac Arrhythmias and Sudden Cardiac Death

    Science.gov (United States)

    Rodríguez, Eduardo; Lerma, Claudia; Echeverría, Juan C.; Alvarez-Ramirez, Jose

    2008-02-01

    We applied detrended fluctuation analysis (DFA) to characterize the intra-beat scaling dynamics of electrocardiographic (ECG) recordings from the PhysioNet Sudden Cardiac Death Holter Database. The main finding of this contribution is that, in such recordings involving different types of arrhythmias; the ECG waveform, besides showing a less-random intra-beat dynamics, becomes more regular during bigeminy, ventricular tachycardia (VT) or even atrial fibrillation (AFIB) and ventricular fibrillation (VF) despite the appearance of erratic traces. Thus, notwithstanding that these cardiac rhythm abnormalities are generally considered as irregular and some of them generated by random impulses or wavefronts, the intra-beat scaling properties suggest that regularity dominates the underlying mechanisms of arrhythmias. Among other explanations, this may result from shorted or restricted -less complex- pathways of conduction of the electrical activity within the ventricles.

  5. Role of gap junction channel in the development of beat-to-beat action potential repolarization variability and arrhythmias.

    Science.gov (United States)

    Magyar, Janos; Banyasz, Tamas; Szentandrassy, Norbert; Kistamas, Kornel; Nanasi, Peter P; Satin, Jonathan

    2015-01-01

    The short-term beat-to-beat variability of cardiac action potential duration (SBVR) occurs as a random alteration of the ventricular repolarization duration. SBVR has been suggested to be more predictive of the development of lethal arrhythmias than the action potential prolongation or QT prolongation of ECG alone. The mechanism underlying SBVR is not completely understood but it is known that SBVR depends on stochastic ion channel gating, intracellular calcium handling and intercellular coupling. Coupling of single cardiomyocytes significantly decreases the beat-to-beat changes in action potential duration (APD) due to the electrotonic current flow between neighboring cells. The magnitude of this electrotonic current depends on the intercellular gap junction resistance. Reduced gap junction resistance causes greater electrotonic current flow between cells, and reduces SBVR. Myocardial ischaemia (MI) is known to affect gap junction channel protein expression and function. MI increases gap junction resistance that leads to slow conduction, APD and refractory period dispersion, and an increase in SBVR. Ultimately, development of reentry arrhythmias and fibrillation are associated post-MI. Antiarrhythmic drugs have proarrhythmic side effects requiring alternative approaches. A novel idea is to target gap junction channels. Specifically, the use of gap junction channel enhancers and inhibitors may help to reveal the precise role of gap junctions in the development of arrhythmias. Since cell-to-cell coupling is represented in SBVR, this parameter can be used to monitor the degree of coupling of myocardium.

  6. Retinopathy of Prematurity (ROP)

    Science.gov (United States)

    ... of Prematurity (ROP) Facts About Retinopathy of Prematurity (ROP) This information was developed by the National Eye ... blind from ROP. Are there different stages of ROP? Yes. ROP is classified in five stages, ranging ...

  7. Pharmacotherapy for premature ejaculation

    NARCIS (Netherlands)

    Waldinger, Marcel D

    PURPOSE OF REVIEW: As there are various drugs and different treatment strategies to delay ejaculation, a review of the current drug treatments for premature ejaculation is relevant for daily clinical practice. RECENT FINDINGS: There are four premature ejaculation subtypes: lifelong premature

  8. Pharmacotherapy for premature ejaculation

    NARCIS (Netherlands)

    Waldinger, Marcel D

    2014-01-01

    PURPOSE OF REVIEW: As there are various drugs and different treatment strategies to delay ejaculation, a review of the current drug treatments for premature ejaculation is relevant for daily clinical practice. RECENT FINDINGS: There are four premature ejaculation subtypes: lifelong premature ejacula

  9. Health Issues of Premature Babies

    Science.gov (United States)

    ... Text Size Email Print Share Health Issues of Premature Babies Page Content Because premature babies are born before they are physically ready ... associated with prematurity. Because of these health concerns, premature babies are given extra medical attention and assistance ...

  10. Disruption of cardiac cholinergic neurons enhances susceptibility to ventricular arrhythmias

    Science.gov (United States)

    Jungen, Christiane; Scherschel, Katharina; Eickholt, Christian; Kuklik, Pawel; Klatt, Niklas; Bork, Nadja; Salzbrunn, Tim; Alken, Fares; Angendohr, Stephan; Klene, Christiane; Mester, Janos; Klöcker, Nikolaj; Veldkamp, Marieke W.; Schumacher, Udo; Willems, Stephan; Nikolaev, Viacheslav O.; Meyer, Christian

    2017-01-01

    The parasympathetic nervous system plays an important role in the pathophysiology of atrial fibrillation. Catheter ablation, a minimally invasive procedure deactivating abnormal firing cardiac tissue, is increasingly becoming the therapy of choice for atrial fibrillation. This is inevitably associated with the obliteration of cardiac cholinergic neurons. However, the impact on ventricular electrophysiology is unclear. Here we show that cardiac cholinergic neurons modulate ventricular electrophysiology. Mechanical disruption or pharmacological blockade of parasympathetic innervation shortens ventricular refractory periods, increases the incidence of ventricular arrhythmia and decreases ventricular cAMP levels in murine hearts. Immunohistochemistry confirmed ventricular cholinergic innervation, revealing parasympathetic fibres running from the atria to the ventricles parallel to sympathetic fibres. In humans, catheter ablation of atrial fibrillation, which is accompanied by accidental parasympathetic and concomitant sympathetic denervation, raises the burden of premature ventricular complexes. In summary, our results demonstrate an influence of cardiac cholinergic neurons on the regulation of ventricular function and arrhythmogenesis. PMID:28128201

  11. [Ventricular tachyarrhythmias in patients with cardiomyopathy

    DEFF Research Database (Denmark)

    Henningsen, K.; Christensen, A.H.; Svendsen, Jesper Hastrup

    2008-01-01

    of patients discharged with the diagnostic codes ventricular tachycardia, ventricular fibrillation or premature ventricular contractions with cardiomyopathy as the presumed aetiology. Patients discharged during a period of 6 years and 5 months were included in the study. The patients were characterized......INTRODUCTION: The purpose of this study was to determine the number and distribution of cardiomyopathies as the aetiology of ventricular tachyarrhythmias among patients discharged from the Department of Cardiology, Rigshospitalet. MATERIALS AND METHODS: The study was a retrospective review......), 57 (45%) patients had arrhythmogenic right ventricular cardiomyopathy (ARVC) and 13 (10%) had hypertrophic cardiomyopathy (HCM). The average age was 44 years for HCM, 41 years for ARVC and 58 years for DCM. The majority of the patients were male. ICD treatment was used in 95% of the patients...

  12. Demonstrations of Beats as Moving Interference Patterns.

    Science.gov (United States)

    Stein, T. S.; Dishman, L. G.

    1982-01-01

    Describes a ripple tank demonstration that displays interference patterns responsible for producing beats and provides photographs of computer simulations of various beat interference patterns. Includes programs for the computer simulation and equations of constructive interference paths in beat interference patterns. (Author/SK)

  13. Impact of potentially lethal ventricular arrhythmias on long-term outcome in patients with chronic heart failure

    Institute of Scientific and Technical Information of China (English)

    LIU Ye-hong; SHEN Wei-feng; SU Jing-ying; WANG Lin-jie; LI Jin-ping; ZHOU Qing-fen; GAN Qian; CHAI Xi-chen; DAI Li-ying; ZHANG Feng-ru

    2012-01-01

    Background Potentially lethal ventricular arrhythmias (PLVAs) occur frequently in survivors after acute myocardial infarction and are increasingly recognized in other forms of structural heart diseases.This study investigated the prevalence and prognostic significance of PLVAs in patients with chronic heart failure (CHF).Methods Data concerning demographics,etiology of heart failure,NYHA functional class,biochemical variables,electrocardiographic and echocardiographic findings,and medical treatments were collected by reviewing hospital medical records from 1080 patients with NYHA Ⅱ-Ⅳ and a left ventricular (LV) ejection fraction ≤45%.PLVAs were defined as multi-focal ventricular ectopy (>30 beats/h on Holter monitoring),bursts of ventricular premature beats,and nonsustained ventricular tachycardia.All-cause mortality,sudden death,and rehospitalization due to worsening heart failure,or cardiac transplantation during 5-year follow-up after discharge were recorded.Results The occurrence rate of PLVAs in CHF was 30.2%,and increased with age; 23.4% in patients <45 years old,27.8% in those between 45-65 years old,and 33.5% in patients >65 years old (P=0.033).Patients with PLVAs had larger LV size and lower ejection fraction (both P <0.01) and higher all-cause mortality (P=0.014) during 5-year follow-up than those without PLVAs.Age (OR 1.041,95% Cl 1.004-1.079,P=0.03) and LV end-diastolic dimension (OR 1.068,95% Cl 1.013-1.126,P=0.015) independently predicted the occurrence of PLVAs.And PLVA was an independent factor for all-cause mortality (RR 1.702,95% Cl 1.017-2.848,P=0.031) and sudden death (RR 1.937,95% CI 1.068-3.516,P=0.030) in patients with CHF.Conclusion PLVAs are common and exert a negative impact on Iona-term clinical outcome in patients with CHF.

  14. Quantum-beat Auger spectroscopy

    CERN Document Server

    Zhang, Song Bin

    2015-01-01

    The concept of nonlinear quantum-beat pump-probe Auger spectroscopy is introduced by discussing a relatively simple four-level model system. We consider a coherent wave packet involving two low-lying states that was prepared by an appropriate pump pulse. This wave packet is subsequently probed by a weak, time-delayed probe pulse with nearly resonant coupling to a core-excited state of the atomic or molecular system. The resonant Auger spectra are then studied as a function of the duration of the probe pulse and the time delay. With a bandwidth of the probe pulse approaching the energy spread of the wave packet, the Auger yields and spectra show quantum beats as a function of pump-probe delay. An analytic theory for the quantum-beat Auger spectroscopy will be presented, which allows for the reconstruction of the wave packet by analyzing the delaydependent Auger spectra. The possibility of extending this method to a more complex manifold of electronic and vibrational energy levels is also discussed.

  15. A case of hybrid closure of a muscular ventricular septal defect: anatomical complexity and surgical management.

    Science.gov (United States)

    Karimi, Mohsen; Hulsebus, Elise; Murdison, Kenneth; Wiles, Henry

    2012-06-01

    Complex muscular ventricular septal defect poses difficult surgical management and is associated with high morbidity and mortality despite advancements in surgical therapy. Device closure of muscular ventricular septal defect has been encouraging and has been used in hybrid approach at a few centres. However, device closure has some limitations in patients with complex muscular ventricular septal defect. We report a case of perventricular device closure of a complex muscular ventricular septal defect in a beating heart with entrapped right ventricular disc and its surgical management.

  16. 胺碘酮配合中药对慢性心力衰竭并室性早搏的临床干预%Clinical intervention of amiodarone with Traditional Chinese Medicine on chronic heart failure and premature ventricular contractions

    Institute of Scientific and Technical Information of China (English)

    于瑞玲; 宗燕

    2014-01-01

    Objective:T o observe the effect of amiodarone with Traditional Chinese Medicine on prev enting the re currence of chronic h eart failure and p remature ventr icular contractions. Me thods:78 cases with ch ronic heart failur e were randomized into a group given amiodarone with Traditional Chinese Medicine( the treatment group with 40 cases) and a group given amiodarone( the control group with 38 cases) .Followed up for six months, the recurrence r ates of premature w ere observ ed . Results:Th e treatment groups:the t otal effective r ate was 98%, th e re currence ra te w as 10.22%; the control group: the to tal effective rat e was 82%, the re currence rate was 32.9%. The dif ference was st atistically sign ificant ( P<0 .05). C onclusions:In the aspect of prevention of chronic h eart fa ilure and premature ventricular contractions, amiodarone with Traditional Chinese Medicine is better than amiodarone and it is worth y of promotion in clinical applications.%目的:观察中药联合胺碘酮预防慢性心力衰竭并室性早搏复发情况。方法:慢性心力衰竭室性早搏病人78例,随机分为中药联合胺碘酮组(治疗组40例)与胺碘酮组(对照组38例)。随访6个月,观察两组早搏复发率情况。结果:治疗组:总有效率分别为98%,复发率10.22%;对照组:总有效率82%,复发率32.9%。两者有显著性差异(P<0.05)。结论:在预防慢性心力衰竭并室性早搏的复发方面中药联合胺碘酮优于单纯应用胺碘酮,值得在临床中推广应用。

  17. Bondage fantasies and beating fantasies.

    Science.gov (United States)

    Weiss, J

    1998-10-01

    Two male patients had masochistic sexual fantasies: one had bondage fantasies, the other beating fantasies. Each patient had been traumatized in childhood by his experiences with a martyr mother. Each had developed the belief that in an intimate sexual relationship with a woman he would hurt her. As a consequence, each tended to suppress his sexuality. Each used masochistic fantasies to reassure himself that he was not hurting his fantasied or real partner. The reassurance made it safe to experience his sexual feelings. The two patients' use of their masochistic fantasies is compared to the fetishist's use of his fetish, as described by Freud.

  18. Efficacy and safety of radiofrequency catheter ablation of premature ventricular contractions origina ting from the right ventricular outflow tract%右心室流出道室性早搏射频消融治疗的有效性和安全性评价

    Institute of Scientific and Technical Information of China (English)

    朱文青; 王张生; 巫慧钧; 周一泉; 许澎; 孙万峰; 冯凯; 谷慧敏; 葛均波

    2009-01-01

    目的 评价应用Carto系统射频消融治疗右心室流出道起源性室性早搏(室早)有效性和安全性.方法 选择2005年5月至2007年12月临床治疗的47例室早患者,其中男性21例,女性26例,平均年龄(34.5±19.2)岁,病程3~38个月.射频所用能量为40 W,时间为120~240 s,温度设定为60℃.分别在消融术前和术后1、3和12个月进行动态心电图检查.结果 47例中成功45例,有效率为95.8%.2例1年后复发新的早搏,未发现任何并发症.结论 应用Carto系统对右心室流出道起源性室早经射频消融治疗是有效和安全的.%Objective To assess efficacy and safety in patients with right ventricular outflow tract (RVOT) arrhythmias treated with radiofrequency catheter ablation (RFCA) combined with electro-anatomical mapping system (Carto). Methods The study group consisted of 47 consecutive patients (mean age 34. 5 ± 19.2 years,range 18~61 years,21 males,26 females) with symptomatic arrhythmias originating from RVOT, who underwent RFCA between Oct. 2005 and Dec. 2007. RFCA was performed with the use of the Carto system. The power of RF current was set at 40 Watts,duration 120~240 seconds,and maximal temperature 60 degrees C. In order to assess RFCA efficacy,a 24-hour Holter ECG monitoring was performed before RFCA and shortly after the procedure as well as one, three and twelve months afterwards. Results Holter ECG monitoring after RFCA showed that the procedure was successful in 45 (95. 8%) patients. In the remaining two patients no sig nificant reduction in the frequency of ventricular ectopy was noted,however,no complex ventricular arrhythmias were observed. None of the complications were observed. Conclusion RFCA with the use of the Carto system is effective and safe in the treatment of arrhythmias originating from RVOT.

  19. Unattended musical beats enhance visual processing.

    Science.gov (United States)

    Escoffier, Nicolas; Sheng, Darren Yeo Jian; Schirmer, Annett

    2010-09-01

    The present study investigated whether and how a musical rhythm entrains a listener's visual attention. To this end, participants were presented with pictures of faces and houses and indicated whether picture orientation was upright or inverted. Participants performed this task in silence or with a musical rhythm playing in the background. In the latter condition, pictures could occur off-beat or on a rhythmically implied, silent beat. Pictures presented without the musical rhythm and off-beat were responded to more slowly than pictures presented on-beat. This effect was comparable for faces and houses. Together these results indicate that musical rhythm both synchronizes and facilitates concurrent stimulus processing.

  20. Electrocardiophysiological characteristics and radiofrequency catheter ablation of frequent premature ventricular contractions originating from aortic sinus of Valsalva%起源于主动脉窦频发室性期前收缩的心电生理特征及射频消融治疗

    Institute of Scientific and Technical Information of China (English)

    陈丽华; 卫展扬; 黄虔; 李大强; 熊斌

    2012-01-01

    Objectives To report the electrocardiophysiological characteristics of frequent premature ventricular contractions (PVCs) originating from the aortic sinus of Valsalva in 11 patients, radiofrequency catheter ablation (RFCA) and its effect. Methods Morphologic characteristics of PVCs in electrocardiography (ECG) and Holter of 11 patients were observed before ablation. Duration and amplitude of r wave in lead V1 were measured. Duration ratio of r/ QRS and amplitude ratio of r/S were calculated respectively. The origin of PVC was determined by pace mapping and activation mapping at the aortic sinus of Valsalva during the operation with coronary arteriography to assist mapping. RFCA was performed afterwards. Results All of the 11 patients had frequent PVCs and 5 of them had recurrent paroxysmal ventricular tachycardias. QRS in leads Ⅱ ,Ⅲ and aVF showed tall R waves. QRS in lead V1 presented in the shape of rs and precordial leads transferred before lead V3. QRS complex in lead V6 presented more in the shape of Rs or a non-S wave. Duration of r wave in lead V1 was (84.6±9.8) ms, which exceeded 50% of the QRS complex. Amplitude ratio of r/S was 0.72±0.31. The local ventricular electrogram at effective target ablation was recorded(35.6± 8.9) ms prior to QRS on electrocardiogram. PVCs were decreased and eliminated after delivering radiofrequency energy for 2-8 seconds at the target site. Conclusions QRS in leads II , III and aVF of PVCs originating from aortic sinus of Valsalva showed tall R waves with a wide duration (>50% of QRS complex) and tall amplitude (>30% of S wave) of r waves in lead V1. Radiofrequency catheter ablation of PVCs at aortic sinus of Valsalva is safe and effective.%目的 报道11例起源于主动脉窦的频发室性期前收缩(premature ventricular contraction,PVC)患者的心电生理特征、射频消融(radiofrequency catheter ablation,RFCA)方法及疗效.方法 分析患者术前体表心电图和动态心电图PVC的特点,测量V1

  1. Micafungin in Premature and Non-premature Infants

    Science.gov (United States)

    Wu, Chunzhang; Tweddle, Lorraine; Roilides, Emmanuel

    2014-01-01

    Background: Invasive fungal infections cause excessive morbidity and mortality in premature neonates and severely ill infants. Methods: Safety and efficacy outcomes of micafungin were compared between prematurely and non-prematurely born infants premature [birth weight (BW) premature, received ≥1 dose of micafungin. Among premature patients, 14.5% were low BW (1500–2499 g), 36.4% very low BW (1000–1499 g) and 49.1% extremely low BW (premature)] died. Significantly more non-premature than premature patients discontinued treatment (P = 0.003). Treatment-related adverse events were recorded in 23% of patients with no difference between groups. More extremely low BW (n = 4, 15%) and very low BW (n = 8, 40%) infants experienced treatment-related adverse events than low BW (n = 0) and there was no relation to micafungin dose or duration. For a subgroup of 30 patients with invasive candidiasis, treatment success was achieved in 73% in both premature and non-premature groups. Prophylaxis was successful in 4/5 non-premature hematopoietic stem cell transplant patients. Conclusion: Micafungin has a safe profile in premature and non-premature infants with substantial efficacy. PMID:24892849

  2. [Ventricular tachyarrhythmias. A retrospective analysis of etiology, demography and treatment

    DEFF Research Database (Denmark)

    Christensen, A.H.; Henningsen, K.; Svendsen, Jesper Hastrup

    2008-01-01

    to ventricular tachyarrhythmias. MATERIALS AND METHODS: We conducted a retrospective review of 993 patients discharged from Rigshospitalet over 6 years and 5 months with the diagnostic codes ventricular tachycardia, ventricular fibrillation or premature ventricular contractions. RESULTS: The population had...... an average age of 59 years (ranging 15-95 years) with a majority of males (76%). Among the patients with known etiology ischemic heart disease (60%), dilated cardiomyopathy (6%) and arrhythmogenic right ventricular cardiomyopathy (6%) were the most frequent. A substantial number of the patients (15%) had...... unknown etiology; 492 (50%) of the patients overall had an ICD implanted, the majority of whom had been categorized as having ventricular tachycardia (92%); 168 patients had previous cardiac arrest, 127 of whom did not have a potential reversible cause. Of this group 75 (59%) had an ICD implanted...

  3. In vivo electroporation mediated gene delivery to the beating heart.

    Directory of Open Access Journals (Sweden)

    Erick L Ayuni

    Full Text Available Gene therapy may represent a promising alternative strategy for cardiac muscle regeneration. In vivo electroporation, a physical method of gene transfer, has recently evolved as an efficient method for gene transfer. In the current study, we investigated the efficiency and safety of a protocol involving in vivo electroporation for gene transfer to the beating heart. Adult male rats were anesthetised and the heart exposed through a left thoracotomy. Naked plasmid DNA was injected retrograde into the transiently occluded coronary sinus before the electric pulses were applied. Animals were sacrificed at specific time points and gene expression was detected. Results were compared to the group of animals where no electric pulses were applied. No post-procedure arrhythmia was observed. Left ventricular function was temporarily altered only in the group were high pulses were applied; CK-MB (Creatine kinase and TNT (Troponin T were also altered only in this group. Histology showed no signs of toxicity. Gene expression was highest at day one. Our results provide evidence that in vivo electroporation with an optimized protocol is a safe and effective tool for nonviral gene delivery to the beating heart. This method may be promising for clinical settings especially for perioperative gene delivery.

  4. Notes on the beating fantasy.

    Science.gov (United States)

    Sirois, François J

    2010-06-01

    This theoretical paper revisits the beating fantasy, which constitutes a crossroads of the psychic economy in that it condenses three primal phantasies, namely the primal scene, castration and seduction. Two forms of the phantasy have been distinguished: a 'fixed' form, apparently associated with the masochistic perversion, and a 'transitory' form, probably bound up with libidinal development. In Freud 's (1919) paper these two aspects are intertwined. The present contribution confines itself to the transitory form of the phantasy and its significance in the libidinal development of the girl, notably in the organization of passivity. With this in mind, particular attention is paid to the phantasy's third phase in this context, and an attempt made to show how this phase epitomizes the transformation of the instinctual pressure and might therefore be looked upon in this connection as the intermediate phase of the phantasy.

  5. Elastic interactions synchronize beating in cardiomyocytes.

    Science.gov (United States)

    Cohen, Ohad; Safran, Samuel A

    2016-07-13

    Motivated by recent experimental results, we study theoretically the synchronization of the beating phase and frequency of two nearby cardiomyocyte cells. Each cell is represented as an oscillating force dipole in an infinite, viscoelastic medium and the propagation of the elastic signal within the medium is predicted. We examine the steady-state beating of two nearby cells, and show that elastic interactions result in forces that synchronize the phase and frequency of beating in a manner that depends on their mutual orientation. The theory predicts both in-phase and anti-phase steady-state beating depending on the relative cell orientations, as well as how synchronized beating varies with substrate elasticity and the inter-cell distance. These results suggest how mechanics plays a role in cardiac efficiency, and may be relevant for the design of cardiomyocyte based micro devices and other biomedical applications.

  6. Dental anesthetic management of a patient with ventricular arrhythmias.

    OpenAIRE

    Miller, R A; Siegelman, L. I.

    1998-01-01

    During routine deep sedation for endodontic therapy, a dentist-anesthesiologist observed premature ventricular contractions (PVCs) on a 62-yr-old woman's electrocardiogram (EKG) tracing. The dentist was able to complete the root canal procedure under intravenous (i.v.) sedation without any problems. The dentist-anesthesiologist referred the patient for medical evaluation. She was found to be free from ischemic cardiac disease with normal ventricular function. The patient was cleared to contin...

  7. Epicardial radiofrequency ablation for left ventricular aneurysm related ventricular arrhythmias during off-pump coronary artery bypass surgery

    Institute of Scientific and Technical Information of China (English)

    YU Yang; GAO Ming-xin; LI Hai-tao; ZHANG Fan; GU Cheng-xiong

    2012-01-01

    Background Left ventricular aneurysm (LVA) is one of the serious complications after acute myocardial infarction.We attempted to evaluate the preliminary efficacy of LVA repair combined with epicardial radiofrequency ablation for ventricular arrhythmia during off-pump coronary artery bypass grafting (OPCAB).Methods From June 2009 to April 2011,31 patients with LVA had angina symptoms and ventricular arrhythmia.In all patients,circular and cross-shaped radiofrequency epicardial ablations were performed using unipolar ablation pen along the border between the aneurysm wall and normal cardiac tissue and in the central zone of the aneurysms,followed by a linear placation of ventricular aneurysms on beating heart.Results All the patients showed complete recovery.The average number of grafted vessels was 2.7±1.3.Intraoperative examinations revealed that the ventricular arrhythmia was effectively controlled by radiofrequency ablation.All cases had been followed up for one year.Holter monitoring revealed a significant reduction in ventricular arrhythmias (P <0.05).Echocardiography showed significant increase in left ventricular ejection fraction (P <0.05) and decrease in left ventricular end-diastolic diameter (P <0.05).Conclusions For patients with ventricular aneurysm and preoperative malignant arrhythmia,aneurysm repair plus epicardial radiofrequency ablation in OPCAB was found to be an effective and feasible therapeutic technique.However,medium-to long-term therapeutic efficacy of this method remains to be determined by future studies and observations.

  8. Determinants of Left Ventricular Mass and Hypertrophy in Hemodialysis Patients Assessed by Cardiac Magnetic Resonance Imaging

    OpenAIRE

    Patel, Rajan K.; Oliver, Scott; Mark, Patrick B.; Powell, Joanna R.; Emily P. McQuarrie; Traynor, James P.; Dargie, Henry J.; Jardine, Alan G.

    2009-01-01

    Background and objectives: Left ventricular hypertrophy (LVH) is an independent risk factor for premature cardiovascular death in hemodialysis (HD) patients and one of the three forms of uremic cardiomyopathy. Cardiovascular magnetic resonance (CMR) is a volume-independent technique to assess cardiac structure. We used CMR to assess the determinants of left ventricular mass (LVM) and LVH in HD patients.

  9. Electrical Brain Responses to Beat Irregularities in Two Cases of Beat Deafness.

    Science.gov (United States)

    Mathias, Brian; Lidji, Pascale; Honing, Henkjan; Palmer, Caroline; Peretz, Isabelle

    2016-01-01

    Beat deafness, a recently documented form of congenital amusia, provides a unique window into functional specialization of neural circuitry for the processing of musical stimuli: Beat-deaf individuals exhibit deficits that are specific to the detection of a regular beat in music and the ability to move along with a beat. Studies on the neural underpinnings of beat processing in the general population suggest that the auditory system is capable of pre-attentively generating a predictive model of upcoming sounds in a rhythmic pattern, subserved largely within auditory cortex and reflected in mismatch negativity (MMN) and P3 event-related potential (ERP) components. The current study examined these neural correlates of beat perception in two beat-deaf individuals, Mathieu and Marjorie, and a group of control participants under conditions in which auditory stimuli were either attended or ignored. Compared to control participants, Mathieu demonstrated reduced behavioral sensitivity to beat omissions in metrical patterns, and Marjorie showed a bias to identify irregular patterns as regular. ERP responses to beat omissions reveal an intact pre-attentive system for processing beat irregularities in cases of beat deafness, reflected in the MMN component, and provide partial support for abnormalities in later cognitive stages of beat processing, reflected in an unreliable P3b component exhibited by Mathieu-but not Marjorie-compared to control participants. P3 abnormalities observed in the current study resemble P3 abnormalities exhibited by individuals with pitch-based amusia, and are consistent with attention or auditory-motor coupling accounts of deficits in beat perception.

  10. Electrical brain responses to beat irregularities in two cases of beat deafness

    Directory of Open Access Journals (Sweden)

    Brian eMathias

    2016-02-01

    Full Text Available Beat deafness, a recently documented form of congenital amusia, provides a unique window into functional specialization of neural circuitry for the processing of musical stimuli: Beat-deaf individuals exhibit deficits that are specific to the detection of a regular beat in music and the ability to move along with a beat. Studies on the neural underpinnings of beat processing in the general population suggest that the auditory system is capable of pre-attentively generating a predictive model of upcoming sounds in a rhythmic pattern, subserved largely within auditory cortex and reflected in mismatch negativity (MMN and P3 event-related potential (ERP components. The current study examined these neural correlates of beat perception in two beat-deaf individuals, Mathieu and Marjorie, and a group of control participants under conditions in which auditory stimuli were either attended or ignored. Compared to control participants, Mathieu demonstrated reduced behavioral sensitivity to beat omissions in metrical patterns, and Marjorie showed a bias to identify irregular patterns as regular. ERP responses to beat omissions reveal an intact pre-attentive system for processing beat irregularities in cases of beat deafness, reflected in the MMN component, and provide partial support for abnormalities in later cognitive stages of beat processing, reflected in an unreliable P3b component exhibited by Mathieu – but not Marjorie – compared to control participants. P3 abnormalities observed in the current study resemble P3 abnormalities exhibited by individuals with pitch-based amusia, and are consistent with attention or auditory-motor coupling accounts of deficits in beat perception.

  11. Dynamic focusing in the zebrafish beating heart

    Science.gov (United States)

    Andrés-Delgado, L.; Peralta, M.; Mercader, N.; Ripoll, J.

    2016-03-01

    Of the large amount of the animal models available for cardiac research, the zebrafish is extremely valuable due to its transparency during early stages of development. In this work a dual illumination laser sheet microscope with simultaneous dual camera imaging is used to image the beating heart at 200 fps, dynamically and selectively focusing inside the beating heart through the use of a tunable lens. This dual color dynamic focusing enables imaging with cellular resolution at unprecedented high frame rates, allowing 3D imaging of the whole beating heart of embryonic zebrafish.

  12. Increased left ventricular mass in normotensive type 1 diabetic patients with diabetic nephropathy

    DEFF Research Database (Denmark)

    Sato, A; Tarnow, L; Parving, H H

    1998-01-01

    OBJECTIVE: Diabetic nephropathy increases the risk of premature cardiovascular disease and sudden death, particularly in type 1 diabetic patients. One possible mechanism for this risk may be left ventricular hypertrophy. In our study, we aimed to evaluate left ventricular structure and function...... to the increased cardiac morbidity and mortality in normotensive type 1 diabetic patients with diabetic nephropathy. Glycemic abnormalities and activation of the renin-angiotensin system may lead to the ventricular enlargement....

  13. Ventricular dyssynchrony as a cause of structural disease in the heart of Dorper sheep

    Directory of Open Access Journals (Sweden)

    J. Ker

    2004-11-01

    Full Text Available Ventricular dyssynchrony is a disturbance of the normal, organized electromechanical coupling of the two ventricles. This condition has many causes, such as left bundle branch block, ventricular preexcitation, right ventricular pacing and right ventricular premature ventricular complexes (PVCs. Ventricular dyssynchrony has many adverse haemodynamic effects on the left ventricle and we wanted to know whether these adverse haemodynamic effects might have any structural consequences on the left ventricles of such hearts. Six healthy Dorper wethers were subjected to numerous right ventricular PVCs to induce ventricular dyssynchrony in order to determine whether any structural consequences will occur in the left ventricles of these hearts. Myocarditis in the musculature of the left ventricles of all six these hearts was seen.

  14. Beating Depression …Help Is Available

    Science.gov (United States)

    ... Navigation Bar Home Current Issue Past Issues Beating Depression …Help Is Available Past Issues / Summer 2007 Table ... treatments are available from your physician. Types of Depression Just like other illnesses, such as heart disease, ...

  15. High Blood Pressure: Keep the Beat Recipes

    Science.gov (United States)

    ... of this page please turn Javascript on. Feature: High Blood Pressure Keep the Beat Recipes Past Issues / Fall 2011 ... 65 million American adults—one in three—with high blood pressure, you have probably heard the advice, "watch your ...

  16. The impact of binaural beats on creativity

    National Research Council Canada - National Science Library

    Reedijk, Susan A; Bolders, Anne; Hommel, Bernhard

    2013-01-01

    .... In the current study we hypothesized that creativity can be influenced by means of binaural beats, an auditory illusion that is considered a form of cognitive entrainment that operates through...

  17. Visualizing acoustical beats with a smartphones

    CERN Document Server

    Giménez, Marcos H; Castro-Palacio, Juan C; Gómez-Tejedor, José A; Monsoriu, Juan A

    2016-01-01

    In this work, a new Physics laboratory experiment on Acoustics beats is presented. We have designed a simple experimental setup to study superposition of sound waves of slightly different frequencies (acoustic beat). The microphone of a smartphone is used to capture the sound waves emitted by two equidistant speakers from the mobile which are at the same time connected to two AC generators. The smartphone is used as a measuring instrument. By means of a simple and free AndroidTM application, the sound level (in dB) as a function of time is measured and exported to a .csv format file. Applying common graphing analysis and a fitting procedure, the frequency of the beat is obtained. The beat frequencies as obtained from the smartphone data are compared with the difference of the frequencies set at the AC generator. A very good agreement is obtained being the percentage discrepancies within 1 %.

  18. Lifestyle influences on prematurity.

    Science.gov (United States)

    Creasy, R K

    1991-01-01

    It is apparent from this review that the lifestyle of an individual gravida can potentially lead to a premature delivery. Some of these adverse behavioral characteristics may be dealt with by education and motivation, and some with actual medical treatment. However, there also appears to be significant need for public policy reorientation if we are to make a significant impact on the problem of preterm delivery.

  19. New Features of Electrocardiogram in a Case Report of Arrhythmogenic Right Ventricular Cardiomyopathy: A Care-Compliant Article.

    Science.gov (United States)

    Pei, Haifeng; Yu, Qiujun; Su, Xiaohua; Wang, Zhen; Zhao, Heng; Yang, Dachun; Yang, Yongjian; Li, De

    2016-04-01

    Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a crucial health problem. With sudden death often being the first presentation, early diagnosis for ARVC is essential. Up to date, electrocardiogram (ECG) is a widely used diagnostic method without invasive harms. To diagnose and treat ARVC as well as possible, we should clearly elucidate its pathophysiological alterations. A 66-year-old farmer presented to the Emergency Department with continuous palpitation, chest tightness, profuse sweating, and nausea with no obvious predisposing causes. An ECG indicated ventricular tachycardia (VT). The patient experienced a sudden drop in blood pressure and acute confusion. After an immediate electrical conversion, his consciousness was gradually restored, and symptoms relieved. The patient was then transferred to the Department of Cardiology to receive ECG, echocardiography, coronary angiogram, biochemical assays, endocardiac tracing, and radiofrequency ablation. In the end, he was diagnosed with ARVC, evidenced by bilateral ventricle dilation and epsilon waves in leads V1-V3. Appropriate therapies were provided for this patient including pharmacological intervention and radiofrequency ablation. Although the diagnosis of ARVC is not difficult, this patient's ECG manifested several interesting features and should be further investigated: T wave inversions were found extensively in the anterior and inferior leads, revealing the involvement of bilateral ventricles; VTs with different morphologies and cycle lengths were found, and some VTs manifested the feature of irregularly irregular rhythm, reminding us to carefully differentiate some special VTs from atrial fibrillation (AF); and epsilon waves gradually appeared in leads V1-V3 and avR since the onset of ARVC. Most importantly, the epsilon waves behind QRS complex appeared in both sinus rhythm and ventricular premature beats/VT originating from cardiac apex, whereas the epsilon waves prior to QRS complex occurred in

  20. 频发室性早搏患儿心脏储备功能的变化及心肺运动试验的应用研究%Effect of frequent premature ventricular contraction on cardiac reserve function in children and clinical application of cardiopulmonary exercise test

    Institute of Scientific and Technical Information of China (English)

    郑彤; 汪芸; 刘艳; 任军; 赵地; 石琳

    2012-01-01

    目的 观察频发室性早搏(premature ventricular contraction,PVC)患儿磷酸肌酸治疗前、后的心肺运动试验(cardiopulmonary exercise test,CPET)各项参数变化,比较与正常儿童的差异,了解频发PVC对患儿心脏储备功能的影响.方法 采用心肺运动测试系统和活动平板对109例频发PVC患儿于治疗前、后分别进行CPET及98例健康儿童进行CPET,记录3组CPET指标,包括最大公斤体重摄氧量(maximal oxygen consumption/kg,VO2max/kg)、最大每搏摄氧量(maximal oxygen consumption/heart rate,VO2max/HR)、不同时段HR、无氧阈(anaerobic threshold,AT)、无氧阈占预计最大摄氧量的百分比( AT/VO2max pred).结果 频发PVC患儿组磷酸肌酸治疗前VO2max/kg、VO2max/HR及AT分别为(22.9 ±7.4)ml/(kg·min)、(9.3±1.5)ml、(15.5±2.7)ml/(kg·min),治疗后分别为(26.4±6.0) ml/(kg·min)、(11.4±3.3) ml、(17.4±3.8)ml/(kg·min),频发PVC患儿治疗后VO2max/kg、VO2max/HR、AT明显高于治疗前,差异均有统计学意义:VO2max/kg(t =2.11,P<0.001)、VO2max/HR(t=4.02,P<0.001)、AT(t=10.2,P<0.001).健康对照组进行的运动试验结果判定皆为阴性.结论 频发PVC患儿心脏储备功能降低,经临床治疗后,运动耐力得到改善,心脏储备功能增强,CPET可较好地反映患儿心脏储备功能的变化.%Objective To observe the changes in cardiopulmonary exercise test (CPET) variables of children with frequent premature ventricular contraction (PVC)before and after creatine phosphate treatment,to examine the difference of CPET results between PVC patients and healthy children,and to evaluate the effect of frequent PVC on the cardiac reserve function in children.Methods One hundred and nine frequent PVC children and 98 healthy children underwent treadmill exercise test and CPET respectively,the changes of CPET variables were observed among patients before and after treatment as well as among the healthy children.CPET variables include maximal oxygen

  1. Amplitude differences least squares method applied to temporal cardiac beat alignment

    Energy Technology Data Exchange (ETDEWEB)

    Correa, R O [Gabinete de TecnologIa Medica, Facultad de Ingenieria, Universidad Nacional de San Juan (Argentina); Laciar, E [Gabinete de TecnologIa Medica, Facultad de Ingenieria, Universidad Nacional de San Juan (Argentina); Valentinuzzi, M E [Gabinete de TecnologIa Medica, Facultad de Ingenieria, Universidad Nacional de San Juan (Argentina)

    2007-11-15

    High resolution averaged ECG is an important diagnostic technique in post-infarcted and/or chagasic patients with high risk of ventricular tachycardia (VT). It calls for precise determination of the synchronism point (fiducial point) in each beat to be averaged. Cross-correlation (CC) between each detected beat and a reference beat is, by and large, the standard alignment procedure. However, the fiducial point determination is not precise in records contaminated with high levels of noise. Herein, we propose an alignment procedure based on the least squares calculation of the amplitude differences (LSAD) between the ECG samples and a reference or template beat. Both techniques, CC and LSAD, were tested in high resolution ECG's corrupted with white noise and 50 Hz line interference of varying amplitudes (RMS range: 0-100{mu}V). Results point out that LSDA produced a lower alignment error in all contaminated records while in those blurred by power line interference better results were found only within the 0-40 {mu}V range. It is concluded that the proposed method represents a valid alignment alternative.

  2. 三维标测系统指导下希氏束旁室性期前收缩的射频消融及心电图分析%Catheter ablation of para-Hisian ventricular premature guided by 3-dimensional mapping system and ECG analysis

    Institute of Scientific and Technical Information of China (English)

    王洪; 洪浪; 周元凤; 赖珩莉; 陈再华; 欧阳长生; 邱赟

    2012-01-01

    目的:探讨三维标测系统指导下经导管射频消融起源于希氏束旁室性期前收缩(室早)的疗效及安全性.方法:对7例起源于希氏束旁频发室早的患者在三维标测系统指导下行射频消融治疗,其中5例采用Carto标测系统,2例采用Ensite Array系统.采用Carto标测系统者经股静脉送入消融大头至右室,在室早发作时采点建模,建立右室解剖结构及电激动顺序三维图像;采用Ensite Array标测系统者经股静脉送人Array球囊电极至右室流出道,利用消融大头采点,建立右室三维图,并对室早激动起源及出口进行实时标测.在右室三维解剖图上标示出希氏束位置,观察最早激动点与希氏束的距离,对心律失常的最早激动部位消融.冷盐水大头消融功率为25 W,温度为43℃,0.9%氯化钠溶液流量消融时17~20 ml/min,放电间隙2 ml/min.结果:7例患者室早体表心电图呈左束支传导阻滞图形,Ⅰ、Ⅱ、aVL、aVF导联为直立的R波,Ⅲ导联为R、rs、rS、rsR,均为RⅡ>RaVF>RaⅢ,V1导联为QS型.7例患者均在希氏束旁标测到最早激动点,位于希氏束上方(11.29士2.98)mm处,在最早激动点及附近消融成功,室早消失,与术前同样条件静脉滴注异丙肾上腺素不能诱发室早.2例患者术中出现右束支传导阻滞,1例经术中推注地塞米松10 mg后转复正常,另1例术后4d心电图转复正常.随访12~28个月,无复发.结论:三维标测系统指导下经导管射频消融起源于希氏束旁室早安全有效.%Objective:To investigate the safety and efficacy of catheter ablation for para-Hisian ventricular premature (VP) guided by 3-dimensional mapping system ( Carto/Ensite Array). Method: Seven patients suffered from para-Hisian region VP were treated with radiofrequency catheter ablationg guided by 3rdimensional mapping system, in which 5 guided by Carto and 2 by Ensite Array. With the Carto Array, the large—tip electrode catheter was

  3. 流出道起源室性早搏心电图特征及其对射频消融靶点的判断价值%ECG characteristics of outflow tract originated premature ventricular contraction and their location value for radiofrequency ablation target

    Institute of Scientific and Technical Information of China (English)

    孙卫红; 李文华

    2016-01-01

    目的:研究室性早搏(室早)的心电图特征及对流出道室早的定位价值。方法回顾68例成功消融的右室流出道(RVOT)和左室流出道(LOVT)室早患者的图形,测量胸前导联 R/S值、R/S 转换部位、V2导联 QRS 波时限、V2导联 R 波振幅指数和 R 波时限指数,探讨其与射频消融靶点的关系。结果54例起源于 RVOT 与14例起源于 LVOT 的室早患者一般情况无显著差异。RVOT 室早比 LVOT 室早时限更短(P <0.05),R/S 转换在 V1~V2导联的有12例,其中LVOT 11例,特异性91.67%,敏感性78.57%;转换在 V3导联的24例,其中 RVOT 21例,特异性87.50%,敏感性38.89%;转换在 V4~V6导联的为32例 RVOT 患者,特异性100%,敏感性59.26%;V2导联 R 波振幅指数和时限指数对 RVOT 室早的定位价值低于对 LVOT 室早的定位价值(P <0.05)。结论R/S 转换在 V2或 V2之前对 LVOT 的诊断价值大;转换在 V4或 V4之后对 ROVT 的诊断价值大;对于 R/S 转换在 V2~V3导联时,V2导联 QRS 波时限、R 波时限指数和 R 波振幅指数三个指标对确定室早的起源部位具有重要的价值。%Objective To explore the ECG characteristics of premature ventricular contraction (PVC)and their location value for outflow tract originated PVC.Methods Retrospective analysis was performed on the figures of 68 successfully ablated cases with right ventricular outflow tract (RVOT)PVC or left ventricular outflow tract (LVOT)PVC.We measured R/S value of precordial leads,switch site of R/S,QRS complex duration of V2 lead,amplitude and duration indices of R wave in V2 lead,and then discussed the relationship between each of the above index and radiofre-quency ablation target.Results There was no significant difference in general circumstances be-tween 54 RVOT-PVC and 1 4 LVOT-PVC patients.The duration of RVOT-PVC was shorter than that of LVOT-PVC(P <0

  4. The impact of binaural beats on creativity

    Directory of Open Access Journals (Sweden)

    Susan A. Reedijk

    2013-11-01

    Full Text Available Human creativity relies on a multitude of cognitive processes, some of which are influenced by the neurotransmitter dopamine. This suggests that creativity could be enhanced by interventions that either modulate the production or transmission of dopamine directly, or affect dopamine-driven processes. In the current study we hypothesized that creativity can be influenced by means of binaural beats, an auditory illusion that is considered a form of cognitive entrainment that operates through stimulating neuronal phase locking. We aimed to investigate whether binaural beats affect creative performance at all, whether they affect divergent thinking, convergent thinking, or both, and whether possible effects may be mediated by the individual striatal dopamine level. Binaural beats were presented at alpha and gamma frequency. Participants completed a divergent and a convergent thinking task to assess two important functions of creativity, and filled out the Positive And Negative Affect Scale – mood State questionnaire (PANAS-S and affect grid to measure current mood. Dopamine levels in the striatum were estimated using spontaneous eye blink rates (EBRs. Results showed that binaural beats, regardless of the presented frequency, can affect divergent but not convergent thinking. Individuals with low EBRs mostly benefitted from alpha binaural beat stimulation, while individuals with high EBR were unaffected or even impaired by both alpha and gamma binaural beats. This suggests that binaural beats, and possibly other forms of cognitive entrainment, are not suited for a one-size-fits-all approach, and that individual cognitive-control systems need to be taken into account when studying cognitive enhancement methods.

  5. Proarrhythmic electrical remodelling is associated with increased beat-to-beat variability of repolarisation

    DEFF Research Database (Denmark)

    Thomsen, Morten Bækgaard; Oros, Avram; Schoenmakers, Marieke

    2007-01-01

    Acquired long-QT syndrome in combination with increased beat-to-beat variability of repolarisation duration (BVR) is associated with lethal torsades de pointes arrhythmias (TdP) in dogs with remodelled heart after atrioventricular block (AVB). We evaluated the relative contributions of bradycardia...

  6. Premature aging syndrome.

    Science.gov (United States)

    Coppedè, Fabio

    2012-01-01

    Hutchinson-Gilford progeria syndrome and Werner syndrome are two of the best characterized human progeroid diseases with clinical features mimicking physiological aging at an early age. Both disorders have been the focus of intense research in recent years since they might provide insights into the pathology of normal human aging. The chapter contains a detailed description of the clinical features of both disorders and then it focuses on the genetics, the resulting biochemical alterations at the protein level and the most recent findings and hypotheses concerning the molecular basis of the premature aging phenotypes. A description of available diagnostic and therapeutic approaches is included.

  7. [Anesthesic management of thoracic aortic stent graft deployment using rapid ventricular pacing].

    Science.gov (United States)

    Yamagishi, Akio; Kunisawa, Takayuki; Katsumi, Norifumi; Nagashima, Michio; Takahata, Osamu; Iwasaki, Hiroshi

    2008-08-01

    Controlled hypotension is useful for accurate deployment of an aortic endograft. We describe the use of rapid ventricular pacing during thoracic aortic stent graft deployment. Anesthesia was induced and maintained with intravenous propofol and remifentanil. A pulmonary artery catheter with pacing function was introduced, and rapid ventricular pacing was started before stent graft deployment. Pacing mode was VVI and pacing rate was 120-160 beats min(-1). Aortic pressure and flow decreased immediately and were maintained at low levels during surgical manipulation. After stopping rapid ventricular pacing, heart rate and aortic pressure recovered immediately. Rapid ventricular pacing was performed 4 times, and there were no complications such as entailed arrhythmia. With rapid ventricular pacing maneuver, which is thought to cause a rapid change in cardiac output, continuous cardiac output measurement can be a useful monitor. This procedure has advantages over pharmacologic or other methods of aortic pressure reduction. Rapid ventricular pacing is safe and effective during stent graft positioning and deployment.

  8. Biomarkers of brain injury in the premature infant

    Directory of Open Access Journals (Sweden)

    Martha V. Douglas-Escobar

    2013-01-01

    Full Text Available The term encephalopathy of prematurity encompasses not only the acute brain injury (such as intraventricular hemorrhage but also complex disturbance on the infant’s subsequent brain development. In premature infants, the most frequent recognized source of brain injury is intraventricular hemorrhage (IVH and periventricular leukomalacia (PVL. Furthermore 20-25% infants with birth weigh less than 1,500 g will have IVH and that proportion increases to 45% if the birth weight is less than 500-750 g. In addition, nearly 60% of very low birth weight newborns will have hypoxic-ischemic injury. Therefore permanent lifetime neurodevelopmental disabilities are frequent in premature infants. Innovative approach to prevent or decrease brain injury in preterm infants requires discovery of biomarkers able to discriminate infants at risk for injury, monitor the progression of the injury and assess efficacy of neuroprotective clinical trials. In this article, we will review biomarkers studied in premature infants with IVH, Post-hemorrhagic ventricular dilation (PHVD and PVL including: S100b, Activin A, erythropoietin, chemokine CCL 18, GFAP and NFL will also be examined. Some of the most promising biomarkers for IVH are S100β and Activin. The concentrations of TGF-β1, MMP-9 and PAI-1 in cerebrospinal fluid could be used to discriminate patients that will require shunt after post-hemorrhagic ventricular dilation. Neonatal brain injury is frequent in premature infants admitted to the neonatal intensive care and we hope to contribute to the awareness and interest in clinical validation of established as well as novel neonatal brain injury biomarkers.

  9. Intermode beat stabilized laser with frequency pulling.

    Science.gov (United States)

    Yokoyama, S; Araki, T; Suzuki, N

    1994-01-20

    A frequency-stabilized two-mode He-Ne laser has been developed. The intermode beat frequency of the experimental laser was approximately 600 MHz for a 25-cm cavity. The laser frequency in which the mode stands is pulled to the center of the gain curve (frequency pulling). The degree of pulling depends on where the longitudinal modes stand in the broadened gain curve. Beat frequency is thereby changed periodically of the order of hundreds of kilohertz with respect to cavity expansion. The frequency pulling was effectively used for frequency stabilization of the laser. The standing position of the longitudinal mode lights was locked in the gain curve by controlling the change of intermode beat frequency. A microwave mixer was applied to extract the frequency change of the intermode beat. Excellent frequency stability (10(10) for the laser oscillation and 10(6) for the beat frequency) was attained. The polarization orthogonality of the proposed laser was superior to that of Zeeman lasers.

  10. Effect of myocardial protection during beating heart surgery with right sub-axiliary approach

    Institute of Scientific and Technical Information of China (English)

    MA Jie; LI Xin-hua; YAN Zi-xing; LIU Ai-jun; ZHANG Wen-kai; YANG Li-na

    2009-01-01

    Background Cardiac troponin-I (cTnl) is one of the three regulatory subunits of the cardiac troponin which has the high sensibility and specificity of responding to myocardial injury. Studies have demonstrated that cTnl is released into the blood stream within hours following acute myocardial reperfusion injury. The clinical utility of cTnl for the assessment of myocardial damage is that it is more specific than creatine kinase MB (CKMB). This study investigated cTnl as a sensitive marker of myocardial reperfusion injury and its clinical value on beating heart surgery with right sub-axiliary incision. Methods From December 2002 threugh December 2004,100 patients with atrial septal defect (ASD), ventricular septal defect (VSD), atrial septal defect and ventricular septal defect (ASD+VSD), and tetralogy of Fallot were randomly divided into two groups: the treatment group (n=50) was operated on with a beating heart under extracorporeal circulation (ECC), and the control group (n=50) on an conventional arresting heart under ECC. The two groups both used a right sub-axillary incision. Blood samples from a central venous catheter (CVC) were collected before, at the end of aortic clamping, immediately after discontinue cardiopulmonary bypass (CPB), 3, 6, 24, and 48 hours after operation. The Abbott Axsym system with hol-automation fluorescent immunity analyzer was used for the quantitative determination of cTnl. cTnl was detected to investigate the effect of myocardial ischemia reperfusion injury and the clinical value of beating heart surgery with right sub-axillary incision. Results There were no significant differences between the two groups before operation. At the end of aortic clamping and thereafter, cTnl significantly increased in both groups, and reached the peak point at 6 hours after operation. At all the tested points, cTnl was significantly higher in the control group than the beating heart group (P <0.05), especially at 6 hours post operation (P <0.01). The

  11. Left thoracic sympathectomy in a premature infant with long QT syndrome and heart failure.

    Science.gov (United States)

    Surendran, Sushitha; Kumar, Thittamaranahalli K S; Knott-Craig, Christopher J

    2017-01-01

    Left thoracic sympathectomy has been shown to be an effective treatment for adults with long QT syndrome who are refractory to medical therapy. We report the successful use of left thoracic sympathectomy for the management of a 10-week-old premature baby with long QT syndrome and heart failure from a large ventricular septal defect and patent ductus arteriosus.

  12. Ventricular torsional relation to ventricular fiber arrangement

    CERN Document Server

    Ranjbar, Saeed; Meybodi, Mahmood Emami

    2014-01-01

    Left ventricular torsion from helically oriented myofibers is a key parameter of cardiac performance. Physicians observing heart motion on echocardiograms, during cardiac catheterization, or in the operating room, are impressed by the twisting or rotary motion of the left ventricle during systole. Conceptually, the heart has been treated as a pressure chamber. The rotary or torsional deformation has been poorly understood by basic scientists and has lacked clinical relevance. The aim of this paper attempts to discuss about this question: Is ventricular twisting related to ventricular fiber arrangement? That is dependent to an assumed model of the left ventricular structure.

  13. Clinical Study of Wenxin Granule in Treating Chronic Cor Pulmonale Complicated by Premature Ventricular Contractions%稳心颗粒治疗慢性肺源性心脏病合并频发室性期前收缩的临床疗效观察

    Institute of Scientific and Technical Information of China (English)

    王永; 吕高荣

    2012-01-01

    目的 观察稳心颗粒治疗慢性肺源性心脏病(肺心病)合并频发室性期前收缩的临床疗效及不良反应.方法 将130例肺心病合并室性期前收缩患者随机分为治疗组和对照组,每组65例,均给予常规综合治疗,治疗组加用稳心颗粒,1包/次,3次/d,温开水冲服,4周为1个疗程.结果 治疗后治疗组室性期前收缩次数明显下降,心悸、胸闷、气短等临床症状均较对照组好转,且差异有统计学意义(均P<0.01),治疗组临床疗效及心电图的疗效分别为92.3%(60/65)、93.8%(61/65),对照组分别为76.9%(50/65)、75.4%(49/65),两组比较差异有统计学意义(P<0.05).治疗组服药期间未发现与稳心颗粒相关的不良反应.结论 稳心颗粒治疗肺心病合并室性期前收缩具有疗效显著、安全可靠、见效快、无不良反应等诸多优点,值得临床推广应用.%Objective To observe the efficacy and adverse reaction of wenxin granule in the treatment of chronic cor pulmonale combined with premature ventricular contractions ( PVC ). Methods 130 cases of cor pulmonale with PVC were randomly divided into two groups: therapy group and control group both receiving the routine comprehensive treatment. Besides that, the therapy group was administrated additional wenxin granule, each time a packet, 3 times a day, warm boiled water, 4 weeks for a course of treatment. Results After treatment, the PVC times had an obvious decrease in the therapy group and palpitations , chest tightness, shortness of breath and other symptoms all had a better improvement than those in the controls, and the differences were statistically significant ( P < 0. 01 ). Effective rates of clinical treatment and ECG treatment were 92. 3% ( 60/65 ), 93. 8% ( 61/65 ) in the therapy group, and they were 76. 9% ( 50/65 ) and 75. 4% ( 49/65 ) respectively in the control group, the difference was statistically significant ( P <0. 05 ). No adverse reactions related to wenxin granule

  14. Clinical significance of ventricular premature contraction in patients with coronary artery disease combined with obstructive sleep apnea%室性期前收缩频率在阻塞性睡眠呼吸暂停的冠心病者中的临床意义

    Institute of Scientific and Technical Information of China (English)

    臧鑫

    2009-01-01

    Objective To investigate the clinical significance of ventricular premature contraction (VPC) frequen-cy and sympathetic activity in the patients with coronary artery disease combined with obstructive sleep apnea. Methods 125 patients were categorized by apnea-hypopnea index (AHI) into moderate (AHI15) group. Sleep stage was divided into five stages (Wake, S1, S2, S34, and REM). Parameters of heart rate turbulence were calculated. Results VPC frequency was affected significantly by sleep stage (Wake, S2 and REM, F=5.8, P<0.01) and by AHI(F = 8.7, P < 0.01). In Severe group, VPC frequency was higher in REM than in Wake (P=0.011).In contrast, patients in moderate group had fewer VPCs and exhibited sleep stage independence (P=0. 19). Oxygen desat-uration duration per apnea episode was correlated positively with AHI (r2=. 71, P<0.01), and was longer in REM than in non-REM (P <0.01). The heart rate turbulence parameter TS was correlated negatively with oxygen desaturation dura-tion in REM (r2=.06, P=0.014). Conclusion Higher VPC frequency coupled with higher sympathetic activity caused by longer apnea episodes in REM sleep may be one of the reasons for increased nocturnal death in apnca patients.%目的 评价室性期前收缩(VPC)频率及交感活性在惠有阻塞性睡眠呼吸暂停综合征(OSAS)的冠心病患者中的意义.方法 125例中有OSAS的冠心病患者,均行多导睡眠图检查,将患者按AHI值进行分组.睡眠阶段分为清醒组、S1、S2、S34及REM.并对患者心率震荡(HRT)参数进行测量对比.结果 VPC频率受睡眠阶段(清醒期、S2及REM,F=5.8,P<0.005)及AHI(F=8.7,P<0.005)影响;在严重OSAS患者,REM期VPC频率较清醒期为高(P=0.011),相反,中等OSAS患者VPC频率较低,且没有睡眠阶段依赖性(P=0.19).氧失饱和持续间期与AHI成正相关(r2=0.71,P<0.001),且在REM期较非REM期为长(P<0.0001),在REM期HRT参数TS与氧失饱和持续间期成负相关(r2=0.06,P=0.014).结论 REM期高VPC频率可

  15. Load Response of the Flagellar Beat

    Science.gov (United States)

    Klindt, Gary S.; Ruloff, Christian; Wagner, Christian; Friedrich, Benjamin M.

    2016-12-01

    Cilia and flagella exhibit regular bending waves that perform mechanical work on the surrounding fluid, to propel cellular swimmers and pump fluids inside organisms. Here, we quantify a force-velocity relationship of the beating flagellum, by exposing flagellated Chlamydomonas cells to controlled microfluidic flows. A simple theory of flagellar limit-cycle oscillations, calibrated by measurements in the absence of flow, reproduces this relationship quantitatively. We derive a link between the energy efficiency of the flagellar beat and its ability to synchronize to oscillatory flows.

  16. Beat that Word: How Listeners Integrate Beat Gesture and Focus in Multimodal Speech Discourse.

    Science.gov (United States)

    Dimitrova, Diana; Chu, Mingyuan; Wang, Lin; Özyürek, Asli; Hagoort, Peter

    2016-09-01

    Communication is facilitated when listeners allocate their attention to important information (focus) in the message, a process called "information structure." Linguistic cues like the preceding context and pitch accent help listeners to identify focused information. In multimodal communication, relevant information can be emphasized by nonverbal cues like beat gestures, which represent rhythmic nonmeaningful hand movements. Recent studies have found that linguistic and nonverbal attention cues are integrated independently in single sentences. However, it is possible that these two cues interact when information is embedded in context, because context allows listeners to predict what information is important. In an ERP study, we tested this hypothesis and asked listeners to view videos capturing a dialogue. In the critical sentence, focused and nonfocused words were accompanied by beat gestures, grooming hand movements, or no gestures. ERP results showed that focused words are processed more attentively than nonfocused words as reflected in an N1 and P300 component. Hand movements also captured attention and elicited a P300 component. Importantly, beat gesture and focus interacted in a late time window of 600-900 msec relative to target word onset, giving rise to a late positivity when nonfocused words were accompanied by beat gestures. Our results show that listeners integrate beat gesture with the focus of the message and that integration costs arise when beat gesture falls on nonfocused information. This suggests that beat gestures fulfill a unique focusing function in multimodal discourse processing and that they have to be integrated with the information structure of the message.

  17. Stimulation of the cardiopulmonary baroreflex enhances ventricular contractility in awake dogs: a mathematical analysis study.

    Science.gov (United States)

    Sala-Mercado, Javier A; Moslehpour, Mohsen; Hammond, Robert L; Ichinose, Masashi; Chen, Xiaoxiao; Evan, Sell; O'Leary, Donal S; Mukkamala, Ramakrishna

    2014-08-15

    The cardiopulmonary baroreflex responds to an increase in central venous pressure (CVP) by decreasing total peripheral resistance and increasing heart rate (HR) in dogs. However, the direction of ventricular contractility change is not well understood. The aim was to elucidate the cardiopulmonary baroreflex control of ventricular contractility during normal physiological conditions via a mathematical analysis. Spontaneous beat-to-beat fluctuations in maximal ventricular elastance (Emax), which is perhaps the best available index of ventricular contractility, CVP, arterial blood pressure (ABP), and HR were measured from awake dogs at rest before and after β-adrenergic receptor blockade. An autoregressive exogenous input model was employed to jointly identify the three causal transfer functions relating beat-to-beat fluctuations in CVP to Emax (CVP → Emax), which characterizes the cardiopulmonary baroreflex control of ventricular contractility, ABP to Emax, which characterizes the arterial baroreflex control of ventricular contractility, and HR to Emax, which characterizes the force-frequency relation. The CVP → Emax transfer function showed a static gain of 0.037 ± 0.010 ml(-1) (different from zero; P < 0.05) and an overall time constant of 3.2 ± 1.2 s. Hence, Emax would increase and reach steady state in ∼16 s in response to a step increase in CVP, without any change to ABP or HR, due to the cardiopulmonary baroreflex. Following β-adrenergic receptor blockade, the CVP → Emax transfer function showed a static gain of 0.0007 ± 0.0113 ml(-1) (different from control; P < 0.10). Hence, Emax would change little in steady state in response to a step increase in CVP. Stimulation of the cardiopulmonary baroreflex increases ventricular contractility through β-adrenergic receptor system mediation.

  18. Ventricular Arrhythmias in Apparently Normal Hearts: Who Needs an Implantable Cardiac Defibrillator?

    Science.gov (United States)

    Tan, Alex Y; Ellenbogen, Kenneth

    2016-09-01

    Idiopathic ventricular tachycardia is often considered a benign form of ventricular arrhythmia in patients without apparent structural heart disease. However, a subset of patients may develop malignant ventricular arrhythmias and present with syncope and sudden cardiac arrest. Survivors of cardiac arrest are candidates for implantable cardiac defibrillators (ICDs). The indications for ICDs in patients with less than a full-blown cardiac arrest presentation but with electrocardiographically high-risk ectopy features remain uncertain. This article addresses some of the uncertainties and pitfalls in ICD risk stratification in this patient group and explores potential mechanisms for malignant conversion of benign premature ventricular complexes to sustained arrhythmia.

  19. Ventricular septal defect (image)

    Science.gov (United States)

    Ventricular septal defect is a congenital defect of the heart, that occurs as an abnormal opening in ... wall that separates the right and left ventricles. Ventricular septal defect may also be associated with other ...

  20. Premature ovarian failure.

    Science.gov (United States)

    Shelling, Andrew N

    2010-11-01

    Premature ovarian failure (POF) is a common cause of infertility in women, and is characterised by amenorrhoea, hypo-oestrogenism and elevated gonadotrophin levels in women under the age of 40. Known causes include iatrogenic agents that cause permanent damage to the ovaries, such as chemotherapy, radiation therapy and surgery, autoimmune conditions, X-chromosome abnormalities and autosomal genetic conditions. However, few genes have been identified that can explain a substantial proportion of cases of POF. Most women with POF are deeply upset by the diagnosis, partly due to the unexpected menopausal symptoms, but also due to infertility. Therefore, early detection would provide better opportunity for early intervention, and furthermore, the identification of specific gene defects will help to direct potential targets for future treatment.

  1. Apnea of prematurity

    Directory of Open Access Journals (Sweden)

    Piermichele Paolillo

    2013-06-01

    Full Text Available Apnea of prematurity (AOP is one of the most frequent pathologies in the Neonatal Intensive Care Unit, with an incidence inversely related to gestational age. Its etiology is often multi factorial and diagnosis of idiopathic forms requires exclusion of other underlying diseases. Despite being a self-limiting condition which regresses with the maturation of the newborn, possible long-term effects of recurring apneas and the degree of desaturation and bradycardia who may lead to abnormal neurological outcome are not yet clarified. Therefore AOP needs careful evaluation of its etiology and adequate therapy that can be both pharmacological and non-pharmacological. Proceedings of the 9th International Workshop on Neonatology · Cagliari (Italy · October 23rd-26th, 2013 · Learned lessons, changing practice and cutting-edge research

  2. Premature ejaculation: A review

    Directory of Open Access Journals (Sweden)

    Sukumar Reddy Gajjala

    2014-01-01

    Full Text Available Premature ejaculation (PE is a common male sexual disorder. It is defined by the Diagnostic and statistical manual of mental disorders as "ejaculation occurring, without control, on or shortly after penetration and before the person wishes it, causing marked distress or interpersonal difficulty. [1] Although the timing of intravaginal ejaculatory latency time (IELT (i.e., time from penetration to ejaculation is not included in this definition, an IELT of <2 min, or ejaculation occurring before penetration, has been considered consistent with PE. [2] Management involves both the patient and his partner. Therapeutic options should suit both partners and be appropriate to their habit in planning and frequency of intercourse. Follow-up at appropriate intervals to judge efficacy, titrate dosage of pharmacological treatments and ascertain side effects is mandatory.

  3. Intrauterine infection and prematurity.

    Science.gov (United States)

    Gonçalves, Luís F; Chaiworapongsa, Tinnakorn; Romero, Roberto

    2002-01-01

    Intrauterine infection is a major cause of premature labor with and without intact membranes. Intrauterine infection is present in approximately 25% of all preterm births and the earlier the gestational age at delivery, the higher the frequency of intra-amniotic infection. Microorganisms may also gain access to the fetus before delivery. A fetal inflammatory response syndrome elicited in response to microbial products is associated with the impending onset of preterm labor and also with multi-systemic organ involvement in the human fetus and a higher rate of perinatal morbidity. The most common microorganisms involved in intrauterine infections are Ureaplasma urealyticum, Fusobacterium species and Mycoplasma hominis. The role of Chlamydia trachomatis and viruses in preterm labor remain to be determined. Use of molecular microbiology techniques to diagnose intrauterine infection may uncover the role of fastidious microorganisms that have not yet been discovered. Antibiotic administration to patients with asymptomatic bacteriuria is associated with a significant reduction in the rate of preterm birth. However, such benefit has not been demonstrated for patients with bacterial vaginosis, or women who carry Streptococcus agalactia, Ureaplasma urealyticum or Trichomonas vaginalis. Antibiotic administration to patients with preterm premature rupture of membranes is associated with prolongation of pregnancy and a reduction in the rate of clinical chorioamnionitis and neonatal sepsis. The benefit has not been demonstrated in patients with preterm labor and intact membranes. Major efforts are required to determine why some women develop an ascending intrauterine infection and others do not and also what interventions may reduce the deleterious effect of systemic fetal inflammation. Copyright 2002 Wiley-Liss, Inc.

  4. Apnea of Prematurity (For Parents)

    Science.gov (United States)

    ... other babies. The apnea of prematurity does not cause brain damage. A healthy baby who is apnea free for a week will probably never have AOP again. Although sudden infant death syndrome (SIDS) does happen more often in premature infants, no relationship between AOP and SIDS has ...

  5. Noninvasive Stiffness Sensing of Ventricular Wall Based on a Thick-walled Cylinder Model

    Science.gov (United States)

    Higashimori, Mitsuru; Ojio, Takeshi; Takeda, Yasuharu; Sakata, Yasushi; Yamamoto, Kazuhiro; Kaneko, Makoto

    This paper discusses a concept of a noninvasive sensing method that can estimate a left ventricular wall stiffness towards a medical diagnosis. Focusing on not only the strain of ventricular wall but also the displacements of epicardium during diastole of heart beat, we propose an index of ventricular wall stiffness based on a thick-walled cylinder model. Applying the proposed method to the echocardiography, we show statistical results where normal and HFpEF (Heart Failure with preserved Ejection Fraction) can be separated towards a medical diagnosis.

  6. QRS complex duration enhancement as ventricular late potential indicator by signal-averaged ECG using time-amplitude alignments.

    Science.gov (United States)

    Avitia, Roberto L; Reyna, Marco A; Bravo-Zanoguera, Miguel E; Cetto, Lucio A

    2013-04-01

    Ventricular late potentials (VLPs) are small-amplitude waves with a short duration that appear at the end part of the QRS complex, making a QRS complex duration larger. The signal-averaged electrocardiography (ECG) technique enhances VLPs and beats, assuming noise as the only random variable. However, ECG signals are not completely stationary and different elongations appear in both time and amplitude in each beat. This research proposes to use piecewise linear approximation to segment each beat and performs the alignment of the beats using the technique known as derivative dynamic time-warping to have beats better aligned and consequently enhance the presence of VLPs. We recorded high-resolution ECGs (HRECGs) from 50 subjects in supine position with no heart-stroke antecedents. VLPs were created synthetically and added to the HRECGs. Two cases were evaluated: (i) duration of the QRS complexes with VLPs without beats alignment, and (ii) duration of QRS complexes with VLPs using beats alignment in time and amplitude. Considering QRS duration as an indicative of VLP presence, results show that when using beats alignment in time and amplitude it is possible to reach a sensitivity of 0.96 and a specificity of 0.52, as opposed to 0.72 and 0.40, respectively, when using only averaging without beats alignment in time and amplitude.

  7. THz radiation by beating Langmuir waves

    CERN Document Server

    Son, S; Park, J Y

    2013-01-01

    An intense terahertz (THz) radiation generated by the beating of two Langmuir waves, which are excited by the forward Raman scattering, is analyzed theoretically. The radiation energy per shot can be as high as 0.1 J, with the duration of 10 pico-second. Appropriate plasma density and the laser characteristics are examined.

  8. Newborn infants detect the beat in music

    NARCIS (Netherlands)

    Winkler, I.; Háden, G.P.; Ladinig, O.; Sziller, I.; Honing, H.

    2009-01-01

    To shed light on how humans can learn to understand music, we need to discover what the perceptual capabilities with which infants are born. Beat induction, the detection of a regular pulse in an auditory signal, is considered a fundamental human trait that, arguably, played a decisive role in the o

  9. Newborn infants detect the beat in music

    NARCIS (Netherlands)

    Winkler, I.; Háden, G.P.; Ladinig, O.; Sziller, I.; Honing, H.

    2009-01-01

    To shed light on how humans can learn to understand music, we need to discover what the perceptual capabilities with which infants are born. Beat induction, the detection of a regular pulse in an auditory signal, is considered a fundamental human trait that, arguably, played a decisive role in the

  10. Beat the Instructor: An Introductory Forecasting Game

    Science.gov (United States)

    Snider, Brent R.; Eliasson, Janice B.

    2013-01-01

    This teaching brief describes a 30-minute game where student groups compete in-class in an introductory time-series forecasting exercise. The students are challenged to "beat the instructor" who competes using forecasting techniques that will be subsequently taught. All forecasts are graphed prior to revealing the randomly generated…

  11. Mechanical communication in cardiac cell synchronized beating

    Science.gov (United States)

    Nitsan, Ido; Drori, Stavit; Lewis, Yair E.; Cohen, Shlomi; Tzlil, Shelly

    2016-05-01

    Cell-cell communication, which enables cells to coordinate their activity and is essential for growth, development and function, is usually ascribed a chemical or electrical origin. However, cells can exert forces and respond to environment elasticity and to mechanical deformations created by their neighbours. The extent to which this mechanosensing ability facilitates intercellular communication remains unclear. Here we demonstrate mechanical communication between cells directly for the first time, providing evidence for a long-range interaction that induces long-lasting alterations in interacting cells. We show that an isolated cardiac cell can be trained to beat at a given frequency by mechanically stimulating the underlying substrate. Deformations are induced using an oscillatory mechanical probe that mimics the deformations generated by a beating neighbouring cardiac cell. Unlike electrical field stimulation, the probe-induced beating rate is maintained by the cell for an hour after the stimulation stops, implying that long-term modifications occur within the cell. These long-term alterations provide a mechanism for cells that communicate mechanically to be less variable in their electromechanical delay. Mechanical coupling between cells therefore ensures that the final outcome of action potential pacing is synchronized beating. We further show that the contractile machinery is essential for mechanical communication.

  12. Beat the Instructor: An Introductory Forecasting Game

    Science.gov (United States)

    Snider, Brent R.; Eliasson, Janice B.

    2013-01-01

    This teaching brief describes a 30-minute game where student groups compete in-class in an introductory time-series forecasting exercise. The students are challenged to "beat the instructor" who competes using forecasting techniques that will be subsequently taught. All forecasts are graphed prior to revealing the randomly generated…

  13. Anatomical Consideration in Catheter Ablation of Idiopathic Ventricular Arrhythmias.

    Science.gov (United States)

    Yamada, Takumi; Kay, G Neal

    2016-01-01

    Idiopathic ventricular arrhythmias (VAs) are ventricular tachycardias (VTs) or premature ventricular contractions (PVCs) with a mechanism that is not related to myocardial scar. The sites of successful catheter ablation of idiopathic VA origins have been progressively elucidated and include both the endocardium and, less commonly, the epicardium. Idiopathic VAs usually originate from specific anatomical structures such as the ventricular outflow tracts, aortic root, atrioventricular (AV) annuli, papillary muscles, Purkinje network and so on, and exhibit characteristic electrocardiograms based on their anatomical background. Catheter ablation of idiopathic VAs is usually safe and highly successful, but can sometimes be challenging because of the anatomical obstacles such as the coronary arteries, epicardial fat pads, intramural and epicardial origins, AV conduction system and so on. Therefore, understanding the relevant anatomy is important to achieve a safe and successful catheter ablation of idiopathic VAs. This review describes the anatomical consideration in the catheter ablation of idiopathic VAs.

  14. Tachycardia-dependent augmentation of "notched J waves" in a general patient population without ventricular fibrillation or cardiac arrest: not a repolarization but a depolarization abnormality?

    Science.gov (United States)

    Aizawa, Yoshifusa; Sato, Masahito; Kitazawa, Hitoshi; Aizawa, Yoshiyasu; Takatsuki, Seiji; Oda, Eiji; Okabe, Masaaki; Fukuda, Keiichi

    2015-02-01

    J waves can be observed in individuals of the general population, but electrocardiographic characteristics are poorly understood. The purpose of this study was to examine the J-wave dynamicity in a general patient population. The responses of J waves (>0.1 mV above the isoelectric line in 2 contiguous leads) to varying RR intervals were analyzed. Patients with aborted sudden cardiac death, documented ventricular fibrillation, or a family history of sudden cardiac death were excluded. The J-wave amplitude was measured at baseline, in beats with short RR intervals in conducted atrial premature beats (APBs) or atrial stimulation during the electrophysiology study, and in the beats next to APBs with prolonged RR intervals. Mainly notched J waves were identified in 94 of 701 (24.5%) general patients (13.4%), and APBs were present in 23 of 94 (24.5%) patients. The mean baseline amplitude of J waves was 0.20 ± 0.06 mV at the baseline RR interval of 853 ± 152 ms, 0.25 ± 0.11 mV at the RR interval in the conducted APB of 545 ± 133 ms (P = .0018), and 0.19 ± 0.08 mV at the RR interval of 1146 ± 314 ms (P = .3102). The clinical characteristics were not different between patients with and without tachycardia-dependent augmentation of J waves. Augmentation of J waves was confirmed by the electrophysiology study: 0.28 ± 0.12 mV vs 0.42 ± 0.11 mV at baseline and in the beats of atrial stimulation, respectively (P = .0001). However, no bradycardia-dependent augmentation (>0.05 mV) was observed. Such tachycardia-dependent augmentation can represent depolarization abnormality rather than repolarization abnormality. J waves in a general patient population were augmented at shorter RR intervals, but not at prolonged RR intervals. Mechanistically, conduction delay is most likely responsible for this. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  15. Beat Noise Limitation in Coherent Time-Spreading OCDMA Network

    Institute of Scientific and Technical Information of China (English)

    Ken-ichi; Kitayama; Koji; Mutsushima

    2003-01-01

    The BER performance of the coherent time-spreading OCDMA network is analyzed by considering the MAI and beat noises as well as the other additive noises. The influence and solution for the beat noise issue are discussed.

  16. Model for the heart beat-to-beat time series during meditation

    Science.gov (United States)

    Capurro, A.; Diambra, L.; Malta, C. P.

    2003-09-01

    We present a model for the respiratory modulation of the heart beat-to-beat interval series. The model consists of a pacemaker, that simulates the membrane potential of the sinoatrial node, modulated by a periodic input signal plus correlated noise that simulates the respiratory input. The model was used to assess the waveshape of the respiratory signals needed to reproduce in the phase space the trajectory of experimental heart beat-to-beat interval data. The data sets were recorded during meditation practices of the Chi and Kundalini Yoga techniques. Our study indicates that in the first case the respiratory signal has the shape of a smoothed square wave, and in the second case it has the shape of a smoothed triangular wave.

  17. The Impact of Monaural Beat Stimulation on Anxiety and Cognition

    OpenAIRE

    Leila Chaieb; Elke C. Wilpert; Christian Hoppe; Nikolai Axmacher; Juergen Fell

    2017-01-01

    Application of auditory beat stimulation has been speculated to provide a promising new tool with which to alleviate symptoms of anxiety and to enhance cognition. In spite of reportedly similar EEG effects of binaural and monaural beats, data on behavioral effects of monaural beats are still lacking. Therefore, we examined the impact of monaural beat stimulation on anxiety, mood and memory performance. We aimed to target states related to anxiety levels and general well-being, in addition to ...

  18. Beat-to-beat T-wave amplitude variability in the long QT syndrome.

    Science.gov (United States)

    Extramiana, Fabrice; Tatar, Charif; Maison-Blanche, Pierre; Denjoy, Isabelle; Messali, Anne; Dejode, Patrick; Iserin, Frank; Leenhardt, Antoine

    2010-09-01

    Long QT syndrome (LQTS) is a primary electrical disease characterized by QT prolongation and increased repolarization dispersion leading to T-wave amplitude beat-to-beat changes. We aimed to quantify beat-to-beat T-wave amplitude variability from ambulatory Holter recordings in genotyped LQTS patients. Seventy genotyped LQTS patients (mean age 23 +/- 15 years, 42 males, 50% LQT1, 39% LQT2, and 11% LQT3) and 70 normal matched control subjects underwent a 24-h digital Holter recording. Using the Tvar software (Ela Medical, Sorin group), the beat-to-beat variance of the T-wave amplitude (TAV in microV) [corrected] was assessed on 50-ms consecutive clusters during three 1-h periods: one with around average diurnal heart rate (Day Fast), one nocturnal period (Night), and one diurnal period with around average nocturnal heart rate (Day Slow). TAV was increased in LQTS patients during the two diurnal periods but not at night (during the Day Fast period, mean TAV was 34 +/- 20 microV [corrected] in LQTS patients vs. 27 +/- 10 microV [corrected] in controls, P < 0.05). This effect depended on the genotype. In LQT1, TAV was larger when compared with controls for both Day Fast and Slow periods, but in LQT2 only Day Fast shows higher TAV. Oppositely, in LQT3 the TAV was higher than in the control group during the Day slow period (mean TAV = 34 +/- 20 vs. 25 +/- 8 microV [corrected] in controls, P < 0.05). In genotyped LQTS patients beat-to-beat T-wave amplitude variability was increased when compared with control subjects. That pattern was modulated by circadian influences in a gene-dependent manner.

  19. Application of Nexfin noninvasive beat-to-beat arterial blood pressure monitoring in autonomic function testing.

    Science.gov (United States)

    Sipkens, Laura M; Treskes, Kaij; Ariese-Beldman, Karin; Veerman, Derk P; Boer, Christa

    2011-10-01

    Evaluation of autonomic function responses is increasingly important for risk prediction and hemodynamic evaluation in the ambulant and perioperative setting, but requires a noninvasive arterial blood pressure measurement device. This study describes whether a novel noninvasive beat-to-beat arterial blood pressure measurement device (Nexfin HD) is able to reproducibly reflect autonomic function responses in healthy volunteers. Noninvasive beat-to-beat arterial blood pressure measurements (Nexfin HD) were performed in 20 healthy men of 22 ± 3 years. Measurements were performed during supine steady state, controlled breathing (0.125 Hz), passive leg raising, a controlled Valsalva maneuver, and a quick stand test. Finally, relative changes in pulse pressure during autonomic function testing and the test-retest reproducibility were determined. Autonomic function tests induced beat-to-beat arterial blood pressure changes that were accurately monitored by the Nexfin device. The intraclass correlation coefficients for systolic and diastolic arterial blood pressure measurements during supine steady state were agreeable [0.91 (0.82-0.96) and 0.84 (0.69-0.93), respectively]. The reproducibility of blood pressure changes during controlled breathing, passive leg raising, and Valsalva maneuver averaged 0.92 (0.82-0.96), 0.76 (0.50-0.90), and 0.94 (0.89-0.97), respectively. The reproducibility of the pulse pressure variation (PPV) as calculated from controlled breathing-induced changes in the arterial blood pressure (13 ± 5%) was high [0.96 (0.93-0.98)]. This study shows that noninvasive beat-to-beat Nexfin HD arterial blood pressure measurements reproducibly reflect autonomic function responses in healthy volunteers.

  20. Model for the respiratory modulation of the heart beat-to-beat time interval series

    Science.gov (United States)

    Capurro, Alberto; Diambra, Luis; Malta, C. P.

    2005-09-01

    In this study we present a model for the respiratory modulation of the heart beat-to-beat interval series. The model consists of a set of differential equations used to simulate the membrane potential of a single rabbit sinoatrial node cell, excited with a periodic input signal with added correlated noise. This signal, which simulates the input from the autonomous nervous system to the sinoatrial node, was included in the pacemaker equations as a modulation of the iNaK current pump and the potassium current iK. We focus at modeling the heart beat-to-beat time interval series from normal subjects during meditation of the Kundalini Yoga and Chi techniques. The analysis of the experimental data indicates that while the embedding of pre-meditation and control cases have a roughly circular shape, it acquires a polygonal shape during meditation, triangular for the Kundalini Yoga data and quadrangular in the case of Chi data. The model was used to assess the waveshape of the respiratory signals needed to reproduce the trajectory of the experimental data in the phase space. The embedding of the Chi data could be reproduced using a periodic signal obtained by smoothing a square wave. In the case of Kundalini Yoga data, the embedding was reproduced with a periodic signal obtained by smoothing a triangular wave having a rising branch of longer duration than the decreasing branch. Our study provides an estimation of the respiratory signal using only the heart beat-to-beat time interval series.

  1. In time with rhythms : beat perception and sensorimotor synchronisation

    NARCIS (Netherlands)

    Schlichting, Nadine

    2015-01-01

    Music and beat perception are strongly connected to movement, a phenomenon known as sensorimotor synchronisation. Neurophysiologically, simple metronome-like beat sounds entrain neural oscillations, so that the brain oscillates with the same frequency as the beat frequency. The usefulness of being

  2. In time with rhythms : beat perception and sensorimotor synchronisation

    NARCIS (Netherlands)

    Schlichting, Nadine

    2015-01-01

    Music and beat perception are strongly connected to movement, a phenomenon known as sensorimotor synchronisation. Neurophysiologically, simple metronome-like beat sounds entrain neural oscillations, so that the brain oscillates with the same frequency as the beat frequency. The usefulness of being e

  3. Beat Gestures Modulate Auditory Integration in Speech Perception

    Science.gov (United States)

    Biau, Emmanuel; Soto-Faraco, Salvador

    2013-01-01

    Spontaneous beat gestures are an integral part of the paralinguistic context during face-to-face conversations. Here we investigated the time course of beat-speech integration in speech perception by measuring ERPs evoked by words pronounced with or without an accompanying beat gesture, while participants watched a spoken discourse. Words…

  4. Prenatal Stress, Prematurity, and Asthma.

    Science.gov (United States)

    Medsker, Brock; Forno, Erick; Simhan, Hyagriv; Celedón, Juan C

    2015-12-01

    Asthma is the most common chronic disease of childhood, affecting millions of children in the United States and worldwide. Prematurity is a risk factor for asthma, and certain ethnic or racial minorities such as Puerto Ricans and non-Hispanic blacks are disproportionately affected by both prematurity and asthma. In this review, we examine current evidence to support maternal psychosocial stress as a putative link between prematurity and asthma, while also focusing on disruption of the hypothalamic-pituitary-adrenal (HPA) axis and immune responses as potential underlying mechanisms for stress-induced "premature asthma." Prenatal stress may cause not only abnormalities in the HPA axis but also epigenetic changes in the fetal glucocorticoid receptor gene (NR3C1), leading to impaired glucocorticoid metabolism. Moreover, maternal stress can alter fetal cytokine balance, favoring TH2 (allergic) immune responses characteristic of atopic asthma: interleukin 6 (IL-6), which has been associated with premature labor, can promote TH2 responses by stimulating production of IL-4 and IL-13. Given a link among stress, prematurity, and asthma, future research should include birth cohorts aimed at confirming and better characterizing "premature asthma." If confirmed, clinical trials of prenatal maternal stress reduction would be warranted to reduce the burden of these common comorbidities. While awaiting the results of such studies, sound policies to prevent domestic and community violence (eg, from firearms) are justified, not only by public safety but also by growing evidence of detrimental effects of violence-induced stress on psychiatric and somatic health.

  5. Failure of long-term digitalization to prevent rapid ventricular response in patients with paroxysmal atrial fibrillation.

    Science.gov (United States)

    Galun, E; Flugelman, M Y; Glickson, M; Eliakim, M

    1991-04-01

    Digitalis is frequently prescribed to patients with paroxysmal atrial fibrillation to reduce the ventricular rate during subsequent paroxysms. To verify the validity of this assumption, we determined the ventricular rate during paroxysmal atrial fibrillation in 13 patients receiving long-term digoxin therapy (mean plasma digoxin level + 1.28 +/- 0.4 ng/ml) and compared it with that of a group of 14 patients who had not taken digoxin or beta-adrenergic and calcium-blocking agents before the attack. The treated and the untreated groups were similar statistically. The mean ventricular rate of the digitalized patients was 121 +/- 15 beats per minute, while that of the patients in the control group was 118 +/- 16 beats per minute. It is concluded that long-term digoxin therapy is not effective in reducing the ventricular response in patients with paroxysmal atrial fibrillation despite adequate therapeutic levels.

  6. Neurogenesis continues in the third trimester of pregnancy and is suppressed by premature birth.

    Science.gov (United States)

    Malik, Sabrina; Vinukonda, Govindaiah; Vose, Linnea R; Diamond, Daniel; Bhimavarapu, Bala B R; Hu, Furong; Zia, Muhammad T; Hevner, Robert; Zecevic, Nada; Ballabh, Praveen

    2013-01-09

    Premature infants exhibit neurodevelopmental delay and reduced growth of the cerebral cortex. However, the underlying mechanisms have remained elusive. Therefore, we hypothesized that neurogenesis in the ventricular and subventricular zones of the cerebral cortex would continue in the third trimester of pregnancy and that preterm birth would suppress neurogenesis. To test our hypotheses, we evaluated autopsy materials from human fetuses and preterm infants of 16-35 gestational weeks (gw). We noted that both cycling and noncycling Sox2(+) radial glial cells and Tbr2(+) intermediate progenitors were abundant in human preterm infants until 28 gw. However, their densities consistently decreased from 16 through 28 gw. To determine the effect of premature birth on neurogenesis, we used a rabbit model and compared preterm [embryonic day 29 (E29), 3 d old] and term (E32, premature infants, preterm birth suppresses neurogenesis, and hypoxia-mimetic agents might restore neurogenesis, enhance cortical growth, and improve neurodevelopmental outcome of premature infants.

  7. Autoregulation of coronary blood flow in the isolated beating pig heart.

    Science.gov (United States)

    Schampaert, Stéphanie; van 't Veer, Marcel; Rutten, Marcel C M; van Tuijl, Sjoerd; de Hart, Jurgen; van de Vosse, Frans N; Pijls, Nico H J

    2013-08-01

    The isolated beating pig heart model is an accessible platform to investigate the coronary circulation in its truly morphological and physiological state, whereas its use is beneficial from a time, cost, and ethical perspective. However, whether the coronary autoregulation is still intact is not known. Here, we study the autoregulation of coronary blood flow in the working isolated pig heart in response to brief occlusions of the coronary artery, to step-wise changes in left ventricular loading conditions and contractile states, and to pharmacologic vasodilating stimuli. Six slaughterhouse pig hearts (473 ± 40 g) were isolated, prepared, and connected to an external circulatory system. Through coronary reperfusion and controlled cardiac loading, physiological cardiac performance was achieved. After release of a coronary occlusion, coronary blood flow rose rapidly to an equal (maximum) level as the flow during control beats, independent of the duration of occlusion. Moreover, a linear relation was found between coronary blood flow and coronary driving pressure for a wide variation of preload, afterload, and contractility. In addition, intracoronary administration of papaverine did not yield a transient increase in blood flow indicating the presence of maximum coronary hyperemia. Together, this indicates that the coronary circulation in the isolated beating pig heart is in a permanent state of maximum hyperemia. This makes the model excellently suitable for testing and validating cardiovascular devices (i.e., heart valves, stent grafts, and ventricular assist devices) under well-controlled circumstances, whereas it decreases the necessity of sacrificing large mammalians for performing classical animal experiments. © 2013, Copyright the Authors. Artificial Organs © 2013 Wiley Periodicals, Inc. and International Center for Artificial Organs and Transplantation.

  8. Systematic Review of Shensong Yangxin Capsule for Treatment of Ventricular Premature Complexes in Coronary Artery Disease%参松养心胶囊治疗冠心病室性早搏随机对照试验的系统评价

    Institute of Scientific and Technical Information of China (English)

    张萍; 吴立旗; 杨虹婕; 李博; 徐凤芹; 马晓昌

    2015-01-01

    目的:评价参松养心胶囊治疗冠心病室性早搏的有效性及安全性。方法计算机检索 PubMed、Cochrane图书馆临床试验注册数据库、中国生物医学文献数据库(Web版)、中文生物医学期刊数据库(Web版)CMCC、VIP中文科技期刊数据库(Web版)、CNKI中国期刊全文数据库(Web版)、万方数据库,筛选参松养心胶囊治疗冠心病室性早搏的随机对照试验(RCT)或半随机对照试验。用 Jadad评分对纳入研究报告质量进行评价,RevMan5.1.4软件进行 Meta分析。结果共检索到有关参松养心胶囊的文献51篇,经过初筛和严格评价,符合纳入标准的15篇,最终进入 Meta分析共3篇。3项研究均比较了参松养心胶囊和心律宁片(苦参碱制剂)治疗冠心病室性早搏的疗效、心电图疗效、中医证候疗效及不良反应情况。纳入研究的 Jadad评分≥3分。对3项研究的室性早搏有效率合并效应量检验,PP分析结果:RR(fixed)=1.37,95%CI (1.18,1.59),P<0.0001;ITT分析结果:RR(fixed)=1.31,95%CI (1.15,1.54),P<0.0001。心电图疗效评价显示:RR(fixed)=1.48,95%CI (1.15,1.90),P=0.002。中医证候疗效显示:RR (fixed)=1.34,95%CI (1.21,1.49),P<0.0001。结论参松养心胶囊可能为一种治疗冠心病室性早搏的有效药物,但尚需要更多高质量研究以增加证据的强度。%Objective To assess the effectiveness and safety of Shensong Yangxin capsule(SYC)in the treatment of ventricular pre-mature complexes(VPC)in coronary artery disease(CAD).Methods We searched the literature associated with randomized con-trol ed trials(RCT)or quasi RCT of traditional Chinese medicine(TCM)in treating CAD patients with VPC from PubMed(update to Feb 2011),Chinese Biology Medicine disc For Internet (CBM Web)(update to Feb 2011),Chinese Medical Current Content (CM-CC)(update to Feb 2011),VIP Chinese science and Technology Periodical Database (update to Feb 2011),CNKI China Journal Ful text Database

  9. Beat-to-beat cycle length variability of spontaneously beating guinea pig sinoatrial cells: relative contributions of the membrane and calcium clocks.

    Directory of Open Access Journals (Sweden)

    Massimiliano Zaniboni

    Full Text Available The heartbeat arises rhythmically in the sino-atrial node (SAN and then spreads regularly throughout the heart. The molecular mechanism underlying SAN rhythm has been attributed by recent studies to the interplay between two clocks, one involving the hyperpolarization activated cation current If (the membrane clock, and the second attributable to activation of the electrogenic NaCa exchanger by spontaneous sarcoplasmic releases of calcium (the calcium clock. Both mechanisms contain, in principle, sources of beat-to-beat cycle length variability, which can determine the intrinsic variability of SAN firing and, in turn, contribute to the heart rate variability. In this work we have recorded long sequences of action potentials from patch clamped guinea pig SAN cells (SANCs perfused, in turn, with normal Tyrode solution, with the If inhibitor ivabradine (3 µM, then back to normal Tyrode, and again with the ryanodine channels inhibitor ryanodine (3 µM. We have found that, together with the expected increase in beating cycle length (+25%, the application of ivabradine brought about a significant and dramatic increase in beat-to-beat cycle length variability (+50%. Despite the similar effect on firing rate, ryanodine did not modify significantly beat-to-beat cycle length variability. Acetylcholine was also applied and led to a 131% increase of beating cycle length, with only a 70% increase in beat-to-beat cycle length variability. We conclude that the main source of inter-beat variability of SANCs firing rate is related to the mechanism of the calcium clock, whereas the membrane clock seems to act in stabilizing rate. Accordingly, when the membrane clock is silenced by application of ivabradine, stochastic variations of the calcium clock are free to make SANCs beating rhythm more variable.

  10. Newborn infants detect the beat in music.

    Science.gov (United States)

    Winkler, István; Háden, Gábor P; Ladinig, Olivia; Sziller, István; Honing, Henkjan

    2009-02-17

    To shed light on how humans can learn to understand music, we need to discover what the perceptual capabilities with which infants are born. Beat induction, the detection of a regular pulse in an auditory signal, is considered a fundamental human trait that, arguably, played a decisive role in the origin of music. Theorists are divided on the issue whether this ability is innate or learned. We show that newborn infants develop expectation for the onset of rhythmic cycles (the downbeat), even when it is not marked by stress or other distinguishing spectral features. Omitting the downbeat elicits brain activity associated with violating sensory expectations. Thus, our results strongly support the view that beat perception is innate.

  11. The Impact of Monaural Beat Stimulation on Anxiety and Cognition

    Directory of Open Access Journals (Sweden)

    Leila Chaieb

    2017-05-01

    Full Text Available Application of auditory beat stimulation has been speculated to provide a promising new tool with which to alleviate symptoms of anxiety and to enhance cognition. In spite of reportedly similar EEG effects of binaural and monaural beats, data on behavioral effects of monaural beats are still lacking. Therefore, we examined the impact of monaural beat stimulation on anxiety, mood and memory performance. We aimed to target states related to anxiety levels and general well-being, in addition to long-term and working memory processes, using monaural beats within the range of main cortical rhythms. Theta (6 Hz, alpha (10 Hz and gamma (40 Hz beat frequencies, as well as a control stimulus were applied to healthy participants for 5 min. After each stimulation period, participants were asked to evaluate their current mood state and to perform cognitive tasks examining long-term and working memory processes, in addition to a vigilance task. Monaural beat stimulation was found to reduce state anxiety. When evaluating responses for the individual beat frequencies, positive effects on state anxiety were observed for all monaural beat conditions compared to control stimulation. Our results indicate a role for monaural beat stimulation in modulating state anxiety and are in line with previous studies reporting anxiety-reducing effects of auditory beat stimulation.

  12. The Impact of Monaural Beat Stimulation on Anxiety and Cognition.

    Science.gov (United States)

    Chaieb, Leila; Wilpert, Elke C; Hoppe, Christian; Axmacher, Nikolai; Fell, Juergen

    2017-01-01

    Application of auditory beat stimulation has been speculated to provide a promising new tool with which to alleviate symptoms of anxiety and to enhance cognition. In spite of reportedly similar EEG effects of binaural and monaural beats, data on behavioral effects of monaural beats are still lacking. Therefore, we examined the impact of monaural beat stimulation on anxiety, mood and memory performance. We aimed to target states related to anxiety levels and general well-being, in addition to long-term and working memory processes, using monaural beats within the range of main cortical rhythms. Theta (6 Hz), alpha (10 Hz) and gamma (40 Hz) beat frequencies, as well as a control stimulus were applied to healthy participants for 5 min. After each stimulation period, participants were asked to evaluate their current mood state and to perform cognitive tasks examining long-term and working memory processes, in addition to a vigilance task. Monaural beat stimulation was found to reduce state anxiety. When evaluating responses for the individual beat frequencies, positive effects on state anxiety were observed for all monaural beat conditions compared to control stimulation. Our results indicate a role for monaural beat stimulation in modulating state anxiety and are in line with previous studies reporting anxiety-reducing effects of auditory beat stimulation.

  13. Premature ovarian failure

    Directory of Open Access Journals (Sweden)

    Vujović Svetlana

    2012-01-01

    Full Text Available Premature ovarian failure (POF is the occurrence of hypergonadotropic hypoestrogenic amenorrhea in women under the age of forty years. It is idiopathic in 74-90% patients. Known cases can be divided into primary and secondary POF. In primary POF genetic aberrations can involve the X chromosome (monosomy, trisomy, translocations, deletions or autosomes. Genetic mechanisms include reduced gene dosage and non-specific chromosome effects impairing meiosis, decreasing the pool of primordial follicles and increasing atresia due to apoptosis or failure of follicle maturation. Autoimmune ovarian damage is caused by alteration of T-cell subsets and T-cell mediated injury, increase of autoantibody producing B-cells, a low number of effector/cytotoxic lymphocyte, which decreases the number and activity of natural killer cells. Bilateral oophorectomy, chemotherapy, radiotherapy and infections cause the secondary POF. Symptoms of POF include irritability, nervousness, loss of libido, depression, lack of concentration, hot flushes, weight gaining, dry skin, vaginal dryness, frequent infections etc. The diagnosis is confirmed by the level of FSH of over 40 IU/L and estradiol below 50 pmol/L in women aged below 40 years. Biochemical and other hormonal analysis (free thyroxin, TSH, prolactin, testosterone, karyotype (<30 years of age, ultrasound of the breasts and pelvis are advisable. Optimal therapy is combined estrogen progestagen therapy given in a sequential rhythm, after excluding absolute contraindications. Testosterone can be added to adnexectomized women and those with a low libido. Sequential estrogen progestagen replacement therapy is the first line therapy for ovulation induction in those looking for pregnancy and after that oocyte donation will be advised. Appropriate estro-progestagen therapy improves the quality of life and prevents complications such as cardiovascular diseases, osteoporosis, stroke etc.

  14. Diagnosis significance of dynamic electrocardiogram in patients with coronary artery disease ventricular extrasystole%动态心电图监测冠心病室性期前收缩的临床意义

    Institute of Scientific and Technical Information of China (English)

    张武

    2012-01-01

    目的 评价动态心电图诊断室性期前收缩的临床意义.方法 回顾性分析我院248例动态心电图检查有室性期前收缩的患者,根据临床诊断分为研究组(122例,诊断为冠心病)和对照组(126例,诊断排除冠心病).比较两组患者的室性期前收缩的频率、类型及QRS波时限.经临床治疗后,再比较治疗前后的上述指标.结果与对照组相比,研究组患者的室性期前收缩更易频发(χ2 = 21.36,P = 0.006),且多为复杂性(χ2 = 11.42,P = 0.015);QRS波时限明显增加(t = 2.687,P = 0.004).与治疗前相比,研究组治疗后的室性期前收缩发生频率减少(χ2 = 10.12,P = 0.024),且复杂性也较少(χ2 = 9.49,P = 0.033);QRS波时限明显减少(t = 2.165,P = 0.038).结论 动态心电图的室性期前收缩可以对冠心病诊断有辅助价值,且能了解治疗效果.%Objective To evaluate the diagnosis significance of dynamic electrocardiogram in patients with coronary artery disease ventricular extrasystole. Methods Dynamic electrocardiogram was performed in 248 patients with coronary artery disease ventricular extrasystole, and 248 patients were divided into the study group (122 cases with coronary artery disease) and the control group (126 cases without coronary artery disease) in accordance with clinical diagnosis. Then the frequency, type, and QRS duration of ventricular contraction before and after treatment were contrsted between the two groups. Results Premature ventricular beats of patients in study group was easy frequent which compared with control group (x2 = 21.36, P = 0.006), and more for complexity (x2 = 11.42, P = 0.015); the time limit of QRS complex significantly increased (t = 2.687, P = 0.004). Compared with before treatment, incidence of premature ventricular beats of study group was reduced after treatment (x2 = 10.12,P = 0.024), and less for complexity (x2 = 9.49, P = 0.033), and the time limit of QRS complex significantly shorter (t = 2.165, P = 0

  15. Cortical evoked potentials to an auditory illusion: binaural beats.

    Science.gov (United States)

    Pratt, Hillel; Starr, Arnold; Michalewski, Henry J; Dimitrijevic, Andrew; Bleich, Naomi; Mittelman, Nomi

    2009-08-01

    To define brain activity corresponding to an auditory illusion of 3 and 6Hz binaural beats in 250Hz or 1000Hz base frequencies, and compare it to the sound onset response. Event-Related Potentials (ERPs) were recorded in response to unmodulated tones of 250 or 1000Hz to one ear and 3 or 6Hz higher to the other, creating an illusion of amplitude modulations (beats) of 3Hz and 6Hz, in base frequencies of 250Hz and 1000Hz. Tones were 2000ms in duration and presented with approximately 1s intervals. Latency, amplitude and source current density estimates of ERP components to tone onset and subsequent beats-evoked oscillations were determined and compared across beat frequencies with both base frequencies. All stimuli evoked tone-onset P(50), N(100) and P(200) components followed by oscillations corresponding to the beat frequency, and a subsequent tone-offset complex. Beats-evoked oscillations were higher in amplitude with the low base frequency and to the low beat frequency. Sources of the beats-evoked oscillations across all stimulus conditions located mostly to left lateral and inferior temporal lobe areas in all stimulus conditions. Onset-evoked components were not different across stimulus conditions; P(50) had significantly different sources than the beats-evoked oscillations; and N(100) and P(200) sources located to the same temporal lobe regions as beats-evoked oscillations, but were bilateral and also included frontal and parietal contributions. Neural activity with slightly different volley frequencies from left and right ear converges and interacts in the central auditory brainstem pathways to generate beats of neural activity to modulate activities in the left temporal lobe, giving rise to the illusion of binaural beats. Cortical potentials recorded to binaural beats are distinct from onset responses. Brain activity corresponding to an auditory illusion of low frequency beats can be recorded from the scalp.

  16. Preterm labor and premature birth: Are you at risk?

    Science.gov (United States)

    ... labor and premature birth: Are you at risk? Preterm labor and premature birth: Are you at risk? ... for preterm labor and premature birth. What are preterm labor and premature birth? Preterm and premature mean ...

  17. Biomarkers of brain injury in the premature infant.

    Science.gov (United States)

    Douglas-Escobar, Martha; Weiss, Michael D

    2012-01-01

    The term "encephalopathy of prematurity" encompasses not only the acute brain injury [such as intraventricular hemorrhage (IVH)] but also complex disturbance on the infant's subsequent brain development. In premature infants, the most frequent recognized source of brain injury is IVH and periventricular leukomalacia (PVL). Furthermore 20-25% infants with birth weigh less than 1,500 g will have IVH and that proportion increases to 45% if the birth weight is less than 500-750 g. In addition, nearly 60% of very low birth weight newborns will have hypoxic-ischemic injury. Therefore permanent lifetime neurodevelopmental disabilities are frequent in premature infants. Innovative approach to prevent or decrease brain injury in preterm infants requires discovery of biomarkers able to discriminate infants at risk for injury, monitor the progression of the injury, and assess efficacy of neuroprotective clinical trials. In this article, we will review biomarkers studied in premature infants with IVH, Post-hemorrhagic ventricular dilation (PHVD), and PVL including: S100b, Activin A, erythropoietin, chemokine CCL 18, GFAP, and NFL will also be examined. Some of the most promising biomarkers for IVH are S100β and Activin. The concentrations of TGF-β1, MMP-9, and PAI-1 in cerebrospinal fluid could be used to discriminate patients that will require shunt after PHVD. Neonatal brain injury is frequent in premature infants admitted to the neonatal intensive care and we hope to contribute to the awareness and interest in clinical validation of established as well as novel neonatal brain injury biomarkers.

  18. Non-invasive cardiac mapping in clinical practice: Application to the ablation of cardiac arrhythmias.

    Science.gov (United States)

    Dubois, Rémi; Shah, Ashok J; Hocini, Mélèze; Denis, Arnaud; Derval, Nicolas; Cochet, Hubert; Sacher, Frédéric; Bear, Laura; Duchateau, Josselin; Jais, Pierre; Haissaguerre, Michel

    2015-01-01

    Ten years ago, electrocardiographic imaging (ECGI) started to demonstrate its efficiency in clinical settings. The initial application to localize focal ventricular arrhythmias such as ventricular premature beats was probably the easiest to challenge and validates the concept. Our clinical experience in using this non-invasive mapping technique to identify the sources of electrical disorders and guide catheter ablation of atrial arrhythmias (premature atrial beat, atrial tachycardia, atrial fibrillation), ventricular arrhythmias (premature ventricular beats) and ventricular pre-excitation (Wolff-Parkinson-White syndrome) is described here.

  19. Day-to-day reproducibility of Holter beat-by-beat analysis of repolarisation.

    Science.gov (United States)

    Baranowski, Rafał; Popławska, Wanda; Buchner, Teodor; Chojnowska, Lidia; Rydlewska-Sadowska, Wanda

    2003-06-01

    Reproducibility of Holter QT analysis is not well established and has been assessed only in one study. We evaluated the day-to-day reproducibility of different QT parameters--mean and max (four beats basis) 24h QT and QTc (Bazett formula), QT for heart rate 55-60 [QT60], 75-80 [QT80] and 95-100 [QT100] beats/min and QT/RR slope (calculated in moving window of 3000 beats in 50 beat steps). QT intervals were measured from 48h digital ECG (sampled at 256 Hz) recordings using Del Mar Medical's QT software in beat-to-beat fashion. The analysed group consisted of 6 women and 24 men--13 patients with hypertrophic cardiomyopathy, 5 healthy family members of the patients with hypertrophic cardiomyopathy, 7 patients with CAD and 5 with other diseases (hypertension, arrhythmia, aborted sudden death without organic heart disease). Reproducibility was analysed with the methods proposed by Bland and Altman. The overall reproducibility of repolarisation parameters was acceptable. Coefficient of reproducibility for mean 24h QT was 24ms, mean QTc 12ms, max QT 22ms, max QTc 24ms. The best reproducibility was observed for QT60, QT80 and QT100 - 12ms, respectively. The poorest day-to-day reproducibility was recorded for the QT/RR slope parameters, which was related to lower heart rate reproducibility. We can conclude that day-to-day reproducibility of Holter repolarisation analysis is acceptable. QT measurement in narrow heart rate windows has the best reproducibility. Accurate QT analysis requires good quality recording, T wave amplitude above 0.2mV and an interactive QT measurement tool which includes verification, editing abilities.

  20. Ventricular Assist Device Support

    Science.gov (United States)

    Fasseas, Panayotis; Kutalek, Steven P.; Samuels, Fania L.; Holmes, Elena C.; Samuels, Louis E.

    2002-01-01

    We describe herein the cases of 2 patients who had ventricular arrhythmias. In one, a short-term biventricular assist device, the ABIOMED BVS 5000, was placed because the patient had sustained ventricular tachycardia and could not be weaned from cardiopulmonary bypass. Excellent hemodynamic support was maintained for several days while the antiarrhythmic therapy was maximized. Sinus rhythm was restored, and the patient was successfully weaned from the ventricular assist device. However, the substrate for the arrhythmia persisted, and a recurrence, 1 week later, resulted in the patient's death. In the 2nd patient, the use of an implantable left ventricular assist device was successful in temporarily alleviating the ventricular tachycardia associated with ischemic cardiomyopathy. However, after 2 days of device assistance, the patient experienced a recurrence of the tachycardia, which degenerated into ventricular fibrillation with a marked deterioration in the patient's hemodynamics. The arrhythmia persisted despite multiple attempts at external cardioversion, and internal cardioversion and placement of an automatic implantable cardioverter-defibrillator were necessary. This treatment, along with repeated boluses of amiodarone, led to successful suppression of the arrhythmias, and the patient eventually underwent transplantation. The mechanical hemodynamic support of the circulation by ventricular assist devices was effective in supporting these 2 patients who had sustained ventricular arrhythmias. (Tex Heart Inst J 2002;29:33–6) PMID:11995847

  1. Ventricular tachycardia in acromegaly.

    Science.gov (United States)

    Arias, Miguel A; Pachón, Marta; Rodríguez-Padial, Luis

    2011-02-01

    Cases of sudden cardiac death have been reported in patients with acromegaly. Malignant ventricular arrhythmias may play an important role in this fatal complication, but the exact mechanisms are not well understood. We report on an acromegalic patient presenting with documented recurrent syncopal ventricular tachycardia.

  2. The Harvard Beat Assessment Test (H-BAT): a battery for assessing beat perception and production and their dissociation.

    Science.gov (United States)

    Fujii, Shinya; Schlaug, Gottfried

    2013-01-01

    Humans have the abilities to perceive, produce, and synchronize with a musical beat, yet there are widespread individual differences. To investigate these abilities and to determine if a dissociation between beat perception and production exists, we developed the Harvard Beat Assessment Test (H-BAT), a new battery that assesses beat perception and production abilities. H-BAT consists of four subtests: (1) music tapping test (MTT), (2) beat saliency test (BST), (3) beat interval test (BIT), and (4) beat finding and interval test (BFIT). MTT measures the degree of tapping synchronization with the beat of music, whereas BST, BIT, and BFIT measure perception and production thresholds via psychophysical adaptive stair-case methods. We administered the H-BAT on thirty individuals and investigated the performance distribution across these individuals in each subtest. There was a wide distribution in individual abilities to tap in synchrony with the beat of music during the MTT. The degree of synchronization consistency was negatively correlated with thresholds in the BST, BIT, and BFIT: a lower degree of synchronization was associated with higher perception and production thresholds. H-BAT can be a useful tool in determining an individual's ability to perceive and produce a beat within a single session.

  3. The Harvard Beat Assessment Test (H-BAT: A Battery for Assessing Beat Perception and Production and their Dissociation

    Directory of Open Access Journals (Sweden)

    Shinya eFujii

    2013-11-01

    Full Text Available Humans have the abilities to perceive, produce, and synchronize with a musical beat, yet there are widespread individual differences. To investigate these abilities and to determine if a dissociation between beat perception and production exists, we developed the Harvard Beat Assessment Test (H-BAT, a new battery that assesses beat perception and production abilities. H-BAT consists of four subtests: 1 music tapping test (MTT, 2 beat saliency test (BST, 3 beat interval test (BIT, and 4 beat finding and interval test (BFIT. MTT measures the degree of tapping synchronization with the beat of music, whereas BST, BIT, and BFIT measure perception and production thresholds via psychophysical adaptive stair-case methods. We administered the H-BAT on thirty individuals and investigated the performance distribution across these individuals in each subtest. There was a wide distribution in individual abilities to tap in synchrony with the beat of music during the MTT. The degree of synchronization consistency was negatively correlated with thresholds in the BST, BIT, and BFIT: a lower degree of synchronization was associated with higher perception and production thresholds. H-BAT can be a useful tool in determining an individual’s ability to perceive and produce a beat within a single session.

  4. Elastohydrodynamic synchronization of adjacent beating flagella

    Science.gov (United States)

    Goldstein, Raymond E.; Lauga, Eric; Pesci, Adriana I.; Proctor, Michael R. E.

    2016-11-01

    It is now well established that nearby beating pairs of eukaryotic flagella or cilia typically synchronize in phase. A substantial body of evidence supports the hypothesis that hydrodynamic coupling between the active filaments, combined with waveform compliance, provides a robust mechanism for synchrony. This elastohydrodynamic mechanism has been incorporated into bead-spring models in which the beating flagella are represented by microspheres tethered by radial springs as they are driven about orbits by internal forces. While these low-dimensional models reproduce the phenomenon of synchrony, their parameters are not readily relatable to those of the filaments they represent. More realistic models, which reflect the underlying elasticity of the axonemes and the active force generation, take the form of fourth-order nonlinear partial differential equations (PDEs). While computational studies have shown the occurrence of synchrony, the effects of hydrodynamic coupling between nearby filaments governed by such continuum models have been examined theoretically only in the regime of interflagellar distances d large compared to flagellar length L . Yet in many biological situations d /L ≪1 . Here we present an asymptotic analysis of the hydrodynamic coupling between two extended filaments in the regime d /L ≪1 and find that the form of the coupling is independent of the microscopic details of the internal forces that govern the motion of the individual filaments. The analysis is analogous to that yielding the localized induction approximation for vortex filament motion, extended to the case of mutual induction. In order to understand how the elastohydrodynamic coupling mechanism leads to synchrony of extended objects, we introduce a heuristic model of flagellar beating. The model takes the form of a single fourth-order nonlinear PDE whose form is derived from symmetry considerations, the physics of elasticity, and the overdamped nature of the dynamics. Analytical

  5. A new Bayesian Earthquake Analysis Tool (BEAT)

    Science.gov (United States)

    Vasyura-Bathke, Hannes; Dutta, Rishabh; Jónsson, Sigurjón; Mai, Martin

    2017-04-01

    Modern earthquake source estimation studies increasingly use non-linear optimization strategies to estimate kinematic rupture parameters, often considering geodetic and seismic data jointly. However, the optimization process is complex and consists of several steps that need to be followed in the earthquake parameter estimation procedure. These include pre-describing or modeling the fault geometry, calculating the Green's Functions (often assuming a layered elastic half-space), and estimating the distributed final slip and possibly other kinematic source parameters. Recently, Bayesian inference has become popular for estimating posterior distributions of earthquake source model parameters given measured/estimated/assumed data and model uncertainties. For instance, some research groups consider uncertainties of the layered medium and propagate these to the source parameter uncertainties. Other groups make use of informative priors to reduce the model parameter space. In addition, innovative sampling algorithms have been developed that efficiently explore the often high-dimensional parameter spaces. Compared to earlier studies, these improvements have resulted in overall more robust source model parameter estimates that include uncertainties. However, the computational demands of these methods are high and estimation codes are rarely distributed along with the published results. Even if codes are made available, it is often difficult to assemble them into a single optimization framework as they are typically coded in different programing languages. Therefore, further progress and future applications of these methods/codes are hampered, while reproducibility and validation of results has become essentially impossible. In the spirit of providing open-access and modular codes to facilitate progress and reproducible research in earthquake source estimations, we undertook the effort of producing BEAT, a python package that comprises all the above-mentioned features in one

  6. Beating the forger: authenticating ceramic antiquities

    Science.gov (United States)

    Stoneham, Doreen; Stoneham, Marshall

    2010-09-01

    Today's forger may have skills to match the artists and craftsmen of the past. But can they be exposed by scientific methods? Ceramic antiquities - including pottery, porcelains, and bronzes with a casting core - have long been valued, and demonstrable antiquity is crucial. Thermoluminescence provides key evidence as to when the object was fired. We describe the basic ideas, the methods themselves, and some of the potential limitations. Examples illustrate the remarkable ingenuity of forgers, who are making determined efforts to beat the physics-based tests of authenticity.

  7. Record low β beating in the LHC

    Directory of Open Access Journals (Sweden)

    R. Tomás

    2012-09-01

    Full Text Available The LHC is currently operating with a proton energy of 4 TeV and β^{*} functions at the ATLAS and CMS interaction points of 0.6 m. This is close to the design value at 7 TeV (β^{*}=0.55  m and represented a challenge for various aspects of the machine operation. In particular, a huge effort was put into the optics commissioning and an unprecedented peak β beating of around 7% was achieved in a high energy hadron collider.

  8. Beat-to-beat heart rate detection in multi-lead abdominal fetal ECG recordings.

    Science.gov (United States)

    Peters, C H L; van Laar, J O E H; Vullings, R; Oei, S G; Wijn, P F F

    2012-04-01

    Reliable monitoring of fetal condition often requires more information than is provided by cardiotocography, the standard technique for fetal monitoring. Abdominal recording of the fetal electrocardiogram may offer valuable additional information, but unfortunately is troubled by poor signal-to-noise ratios during certain parts of pregnancy. To increase the usability of abdominal fetal ECG recordings, an algorithm was developed that enhances fetal QRS complexes in these recordings and thereby provides a promising method for detecting the beat-to-beat fetal heart rate in recordings with poor signal-to-noise ratios. The method was evaluated on generated recordings with controlled signal-to-noise ratios and on actual recordings that were performed in clinical practice and were annotated by two independent experts. The evaluation on the generated signals demonstrated excellent results (sensitivity of 0.98 for SNR≥1.5). Only for SNRheart rate detection exceeded 2 ms, which may still suffice for cardiotocography but is unacceptable for analysis of the beat-to-beat fetal heart rate variability. The sensitivity and positive predictive value of the method in actual recordings were reduced to approximately 90% for SNR≤2.4, but were excellent for higher signal-to-noise ratios.

  9. Beats on the Table: Beat Writing in the Chicago Review and Big Table

    Directory of Open Access Journals (Sweden)

    Jaap van der Bent

    2012-07-01

    Full Text Available Normal 0 21 false false false NL X-NONE X-NONE MicrosoftInternetExplorer4 Kleine literaire tijdschriften, zogenaamde little magazines, hebben een belangrijke rol gespeeld bij de doorbraak, in de loop van de jaren vijftig, van de Amerikaanse Beat Generation. Aangezien grotere uitgeverijen en de gevestigde tijdschriften lange tijd terugschrokken voor de zowel inhoudelijk als formeel van de norm afwijkende uitingen van de Beats, verscheen hun werk aanvankelijk vooral in kleinere tijdschriften als de twee waaraan in dit artikel aandacht wordt besteed: de Chicago Review en Big Table. Aan de hand van een beschrijving van de inhoud van deze twee tijdschriften wordt geprobeerd duidelijk te maken hoe het werk van de Beat Generation zich in deze tijdschriften gaandeweg een eigen plaats verwierf. Speciale aandacht wordt besteed aan de rol van de redacteuren Irving Rosenthal en Paul Carroll; door zijn uitgekiende strategie om voor het omstreden werk van Beat-auteur William S. Burroughs geleidelijk een steeds grotere plaats in te ruimen, bepaalde vooral Rosenthal het veranderende karakter van de Chicago Review. De veranderingen bij dat tijdschrift verliepen niet zonder slag of stoot en waren voor de eigenaar ervan, de University of Chicago, op een gegeven moment aanleiding om de Chicago Review aan censuur te onderwerpen. Ook deze censuur en de reactie erop, de oprichting van Big Table, worden in het artikel belicht.

  10. Spoken Word Recognition Enhancement Due to Preceding Synchronized Beats Compared to Unsynchronized or Unrhythmic Beats.

    Science.gov (United States)

    Sidiras, Christos; Iliadou, Vasiliki; Nimatoudis, Ioannis; Reichenbach, Tobias; Bamiou, Doris-Eva

    2017-01-01

    The relation between rhythm and language has been investigated over the last decades, with evidence that these share overlapping perceptual mechanisms emerging from several different strands of research. The dynamic Attention Theory posits that neural entrainment to musical rhythm results in synchronized oscillations in attention, enhancing perception of other events occurring at the same rate. In this study, this prediction was tested in 10 year-old children by means of a psychoacoustic speech recognition in babble paradigm. It was hypothesized that rhythm effects evoked via a short isochronous sequence of beats would provide optimal word recognition in babble when beats and word are in sync. We compared speech recognition in babble performance in the presence of isochronous and in sync vs. non-isochronous or out of sync sequence of beats. Results showed that (a) word recognition was the best when rhythm and word were in sync, and (b) the effect was not uniform across syllables and gender of subjects. Our results suggest that pure tone beats affect speech recognition at early levels of sensory or phonemic processing.

  11. Ca(2+)-activated chloride channel activity during Ca(2+) alternans in ventricular myocytes.

    Science.gov (United States)

    Kanaporis, Giedrius; Blatter, Lothar A

    2016-11-01

    Cardiac alternans, defined beat-to-beat alternations in contraction, action potential (AP) morphology or cytosolic Ca transient (CaT) amplitude, is a high risk indicator for cardiac arrhythmias. We investigated mechanisms of cardiac alternans in single rabbit ventricular myocytes. CaTs were monitored simultaneously with membrane currents or APs recorded with the patch clamp technique. A strong correlation between beat-to-beat alternations of AP morphology and CaT alternans was observed. During CaT alternans application of voltage clamp protocols in form of pre-recorded APs revealed a prominent Ca(2+)-dependent membrane current consisting of a large outward component coinciding with AP phases 1 and 2, followed by an inward current during AP repolarization. Approximately 85% of the initial outward current was blocked by Cl(-) channel blocker DIDS or lowering external Cl(-) concentration identifying it as a Ca(2+)-activated Cl(-) current (ICaCC). The data suggest that ICaCC plays a critical role in shaping beat-to-beat alternations in AP morphology during alternans.

  12. Pharmacological Approach for Treatment of Retinopathy of Prematurity

    Directory of Open Access Journals (Sweden)

    İmren Akkoyun

    2012-12-01

    Full Text Available Current standard of screening examination for retinopathy of prematurity (ROP is determined in international guidelines. The criteria for classification and therapy are also determined in international guidelines, and currently, retinal laser fotocoagulation of peripheral avascular retinal area is gold standard (ETROP, Early Treatment for Retinopathy of Prematurity Cooperative Group for proliferative ROP. Vitreoretinal surgery will be used in cases with retinal detachment. In case series after off-label injection of anti-VEGF (vascular endothelial growth factor agent bevacizumab and in the first report of BEAT-ROP study in proliferative ROP the results are promising. Furthermore, beside the intravitreal anti-VEGF therapy, systemic therapy with mediators like IGF-1 (insulin-like growth factor and/or ω3-fatty acids outlines pharmacological approach to treatment of ROP. The results of well-designed clinical trials of intravitreal anti-VEGF therapy and pharmacological systemic therapy with the above-mentioned mediators for ROP are needed in order to provide information as to the balance of risk versus benefit, as well as practical guidance regarding optimal treatment parameters and follow-up.(Turk J Ophthalmol 2012; 42: 466-73

  13. Binaural auditory beats affect vigilance performance and mood.

    Science.gov (United States)

    Lane, J D; Kasian, S J; Owens, J E; Marsh, G R

    1998-01-01

    When two tones of slightly different frequency are presented separately to the left and right ears the listener perceives a single tone that varies in amplitude at a frequency equal to the frequency difference between the two tones, a perceptual phenomenon known as the binaural auditory beat. Anecdotal reports suggest that binaural auditory beats within the electroencephalograph frequency range can entrain EEG activity and may affect states of consciousness, although few scientific studies have been published. This study compared the effects of binaural auditory beats in the EEG beta and EEG theta/delta frequency ranges on mood and on performance of a vigilance task to investigate their effects on subjective and objective measures of arousal. Participants (n = 29) performed a 30-min visual vigilance task on three different days while listening to pink noise containing simple tones or binaural beats either in the beta range (16 and 24 Hz) or the theta/delta range (1.5 and 4 Hz). However, participants were kept blind to the presence of binaural beats to control expectation effects. Presentation of beta-frequency binaural beats yielded more correct target detections and fewer false alarms than presentation of theta/delta frequency binaural beats. In addition, the beta-frequency beats were associated with less negative mood. Results suggest that the presentation of binaural auditory beats can affect psychomotor performance and mood. This technology may have applications for the control of attention and arousal and the enhancement of human performance.

  14. [Experimental principles for preserving annulo-ventricular integrity of the mitral valve].

    Science.gov (United States)

    Gams, E; Schad, H; Heimisch, W

    1996-06-01

    Despite numerous improvement in cardiac surgery the results in mitral valve replacement are still not satisfactory, since impaired left ventricular function continues to be a problem during the postoperative course. In order to investigate the effect of mitral valve replacement on left ventricular function canine experiments were performed: During extracorporeal circulation bileaflet mitral valve prostheses were implanted preserving the ventriculo-annular continuity. Flexible wires were slung around the chordae of the subvalvular mitral apparatus and brought to the outside through the left ventricular wall. Left ventricular diameters were measured by sonomicrometry, left ventricular stroke volume, left ventricular enddiastolic volume and ejection fraction by dye dilution technique as well as left ventricular and aortic pressure by catheter tip manometers. After finishing cardiopulmonary bypass control values were registered and different preload values achieved by volume loading with blood transfusions to left ventricular enddiastolic pressures of 12 mm Hg. Subsequently under normovolumic conditions the chordae tendineae of the anterior and posterior papillary muscles of the mitral valve were cut from the outside, while the heart was beating, by application of electrocautery on the steel wires. Following severance of the ventriculo-annular continuity of the mitral valve again function curves of left ventricular hemodynamics were made during volume transfusions. When the chordae had been divided the left ventricular enddiastolic diameter increased by 10% in the major axis, while in the minor axis no significant changes occurred. The systolic shortening was impaired substantially by reduction of 43% during the ejection phase when the subvalvular mitral apparatus had been severed. Left ventricular enddiastolic volume was increased by 18% at any preload level, while left ventricular ejection fraction was reduced by 16%. Consequently left ventricular stroke volume was

  15. Heritability of ambulatory and beat-to-beat office blood pressure in large multigenerational Arab pedigrees: the 'Oman Family study'.

    Science.gov (United States)

    Albarwani, Sulayma; Muñoz, M Loretto; Voruganti, V Saroja; Jaju, Deepali; Al-Yahyaee, V Saeed; Rizvi, Syed G; Lopez-Alvarenga, Juan C; Al-Anqoudi, Zahir M; Bayoumi, Riad A; Comuzzie, Anthony G; Snieder, Harold; Hassan, Mohammed O

    2012-12-01

    To estimate the heritability of ambulatory blood pressure (BP), heart rate (HR), and beat-to-beat office BP and HR in an isolated, environmentally and genetically homogeneous Omani Arab population. Ambulatory BP measurements were recorded in 1,124 subjects with a mean age of 33.8 ± 16.2 years, using the auscultatory mode of the validated Schiller ambulatory BP Monitor. Beat-to-beat BP and HR were recorded by the Task Force Monitor. Heritability was estimated using quantitative genetic analysis. This was achieved by applying the maximum-likelihood-based variance decomposition method implemented in SOLAR software. We detected statistically significant heritability estimates for office beat-to-beat, 24-hour, daytime, and sleep HR of 0.31, 0.21, 0.20, and 0.07, respectively. Heritability estimates in the above mentioned conditions for systolic BP (SBP)/diastolic BP (DBP)/mean BP (MBP)were all significant and estimated at 0.19/0.19/0.19, 0.30/0.44/0.41, 0.28/0.38/0.39, and 0.21/0.18/0.20,respectively. Heritability estimates for 24-hour and daytime ambulatory SBP, DBP, and MBP ranged from 0.28 to 0.44, and were higher than the heritability estimates for beat-to-beat recordings and sleep periods,which were estimated within a narrow range of 0.18-0.21. In this cohort, because shared environments are common to all, the environmental influence that occurs is primarily due to the variation in non-shared environment that is unique to the individual. We demonstrated significant heritability estimates for both beat-to-beat office and ambulatory BP and HR recordings, but 24-hour and daytime ambulatory heritabilities are higher than those from beat-to-beat resting levels and ambulatory night-time recordings.

  16. Your Premature Baby: Low Birthweight

    Science.gov (United States)

    ... many low-birthweight babies are born prematurely, many risk factors for having a low-birthweight baby are the same for preterm labor and ... risk for having a low-birthweight baby. Medical risk factors for having a low-birthweight baby Preterm labor . This is labor that starts ...

  17. Music Therapy with Premature Infants

    Science.gov (United States)

    Standley, Jayne

    2003-01-01

    Over 20 years of research and clinical practice in music therapy with premature infants has been compiled into this text designed for Board Certified Music Therapists specializing in Neonatal Intensive Care clinical services, for NICU medical staff incorporating research-based music therapy into developmental care plans, and for parents of…

  18. Music Therapy with Premature Infants

    Science.gov (United States)

    Standley, Jayne

    2003-01-01

    Over 20 years of research and clinical practice in music therapy with premature infants has been compiled into this text designed for Board Certified Music Therapists specializing in Neonatal Intensive Care clinical services, for NICU medical staff incorporating research-based music therapy into developmental care plans, and for parents of…

  19. MODERN PRODUCTS FOR FEEDING PREMATURE BABIES

    National Research Council Canada - National Science Library

    A. V. Surzhik

    2012-01-01

    .... Adequate feeding is one of the fundamental factors of premature babies nursing. To ensure a premature baby with all necessary components for power saving in breast milk intake, breast milk fortifiers...

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

    Science.gov (United States)

    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.

  1. Right ventricular dysfunction affects survival after surgical left ventricular restoration.

    Science.gov (United States)

    Couperus, Lotte E; Delgado, Victoria; Palmen, Meindert; van Vessem, Marieke E; Braun, Jerry; Fiocco, Marta; Tops, Laurens F; Verwey, Harriëtte F; Klautz, Robert J M; Schalij, Martin J; Beeres, Saskia L M A

    2017-04-01

    Several clinical and left ventricular parameters have been associated with prognosis after surgical left ventricular restoration in patients with ischemic heart failure. The aim of this study was to determine the prognostic value of right ventricular function. A total of 139 patients with ischemic heart failure (62 ± 10 years; 79% were male; left ventricular ejection fraction 27% ± 7%) underwent surgical left ventricular restoration. Biventricular function was assessed with echocardiography before surgery. The independent association between all-cause mortality and right ventricular fractional area change, tricuspid annular plane systolic excursion, and right ventricular longitudinal peak systolic strain was assessed. The additive effect of multiple impaired right ventricular parameters on mortality also was assessed. Baseline right ventricular fractional area change was 42% ± 9%, tricuspid annular plane systolic excursion was 18 ± 3 mm, and right ventricular longitudinal peak systolic strain was -24% ± 7%. Within 30 days after surgery, 15 patients died. Right ventricular fractional area change (hazard ratio, 0.93; 95% confidence interval, 0.88-0.98; P right ventricular longitudinal peak systolic strain (hazard ratio, 1.15; 95% confidence interval, 1.05-1.26; P Right ventricular function was impaired in 21%, 20%, and 27% of patients on the basis of right ventricular fractional area change, tricuspid annular plane systolic excursion, and right ventricular longitudinal peak systolic strain, respectively. Any echocardiographic parameter of right ventricular dysfunction was present in 39% of patients. The coexistence of several impaired right ventricular parameters per patient was independently associated with increased 30-day mortality (hazard ratio, 2.83; 95% confidence interval, 1.64-4.87, P right ventricular systolic dysfunction is independently associated with increased mortality in patients with ischemic heart failure undergoing surgical left

  2. Left Ventricular Hypertrophy

    Science.gov (United States)

    ... the chamber itself also increases. The enlarged heart muscle loses elasticity and eventually may fail to pump with as much force as needed. Left ventricular hypertrophy is more common in people who have uncontrolled ...

  3. Frank-Starling mechanism retains recirculation fraction of myocardial Ca(2+) in the beating heart.

    Science.gov (United States)

    Mizuno, J; Araki, J; Mohri, S; Minami, H; Doi, Y; Fujinaka, W; Miyaji, K; Kiyooka, T; Oshima, Y; Iribe, G; Hirakawa, M; Suga, H

    2001-12-01

    Myocardial Ca(2+) handling in excitation-contraction coupling is the second primary determinant of energy or O(2) demand in a working heart. The intracellular and extracellular routes remove myocardial Ca(2+) that was released into the sarcoplasma with different Ca(2+): ATP stoichiometries. The intracellular route is twice as economical as the extracellular route. Therefore the fraction of total Ca(2+) removed via the sarcoplasmic reticulum, i.e., the recirculation fraction of intracellular Ca(2+) (RF), determines the economy of myocardial Ca(2+) handling. RF has conventionally been estimated as the exponential decay rate of postextrasystolic potentiation (PESP). However, we have found that PESP usually decays in alternans, but not exponentially in the canine left ventricle beating above 100 beats/min. We have succeeded in estimating RF from the exponential decay component of an alternans PESP. We previously found that the Frank-Starling mechanism or varied ventricular preload did not affect the economy of myocardial Ca(2+) handling. Then, to account for this important finding, we hypothesized that the Frank-Starling mechanism would not affect RF at a constant heart rate. We tested this hypothesis and found its supportive evidence in 11 canine left ventricles. We conclude that RF at a constant heart rate would remain constant, independent of the Frank-Starling mechanism.

  4. Nonlinear amplitude dynamics in flagellar beating

    CERN Document Server

    Oriola, David; Casademunt, Jaume

    2016-01-01

    The physical basis of flagellar and ciliary beating is a major problem in biology which is still far from completely understood. The fundamental cytoskeleton structure of cilia and flagella is the axoneme, a cylindrical array of microtubule doublets connected by passive crosslinkers and dynein motor proteins. The complex interplay of these elements leads to the generation of self-organized bending waves. Although many mathematical models have been proposed to understand this process, few attempts have been made to assess the role of dyneins on the nonlinear nature of the axoneme. Here, we investigate the nonlinear dynamics of flagella by considering an axonemal sliding control mechanism for dynein activity. This approach unveils the nonlinear selection of the oscillation amplitudes, which are typically either missed or prescribed in mathematical models. The explicit set of nonlinear equations are derived and solved numerically. Our analysis reveals the spatiotemporal dynamics of dynein populations and flagell...

  5. Beating Social Democracy on Its Own Turf

    DEFF Research Database (Denmark)

    Arndt, Christoph

    2014-01-01

    parties to flourish in contexts where welfare issues have a natural salience as in the case of universal welfare states. In contrast, Scandinavian universal welfare states ought to benefit social democracy when it comes to issue voting on welfare issues. It is argued in this article that centre-right......Recent elections yielded sweeping majorities for the centre-right in Scandinavia with a decade of pure centre-right majorities in Denmark and the longest sitting centre-right coalition in Sweden for decades. This is a blind spot in the issue voting literature, which would not expect centre-right...... parties can beat social democrats by credibly converging to its social democratic opponent on issues of universal welfare. Issue ownership voting to the benefit of centre-right parties will then be strongest among voters perceiving the centre-right to have converged to social democracy and perceiving...

  6. Computer Simulation of the Beating Human Heart

    Science.gov (United States)

    Peskin, Charles S.; McQueen, David M.

    2001-06-01

    The mechanical function of the human heart couples together the fluid mechanics of blood and the soft tissue mechanics of the muscular heart walls and flexible heart valve leaflets. We discuss a unified mathematical formulation of this problem in which the soft tissue looks like a specialized part of the fluid in which additional forces are applied. This leads to a computational scheme known as the Immersed Boundary (IB) method for solving the coupled equations of motion of the whole system. The IB method is used to construct a three-dimensional Virtual Heart, including representations of all four chambers of the heart and all four valves, in addition to the large arteries and veins that connect the heart to the rest of the circulation. The chambers, valves, and vessels are all modeled as collections of elastic (and where appropriate, actively contractile) fibers immersed in viscous incompressible fluid. Results are shown as a computer-generated video animation of the beating heart.

  7. Outcomes for Extremely Premature Infants

    Science.gov (United States)

    Glass, Hannah C.; Costarino, Andrew T.; Stayer, Stephen A.; Brett, Claire; Cladis, Franklyn; Davis, Peter J.

    2015-01-01

    Premature birth is a significant cause of infant and child morbidity and mortality. In the United States, the premature birth rate, which had steadily increased during the 1990s and early 2000s, has decreased annually for four years and is now approximately 11.5%. Human viability, defined as gestational age at which the chance of survival is 50%, is currently approximately 23–24 weeks in developed countries. Infant girls, on average, have better outcomes than infant boys. A relatively uncomplicated course in the intensive care nursery for an extremely premature infant results in a discharge date close to the prenatal EDC. Despite technological advances and efforts of child health experts during the last generation, the extremely premature infant (less than 28 weeks gestation) and extremely low birth weight infant (ELBW) (premature labor improved neonatal mortality and morbidity in the late 1990s. The recognition that chronic postnatal administration of steroids to infants should be avoided may have improved outcomes in the early 2000s. Evidence from recent trials attempting to define the appropriate target for oxygen saturation in preterm infants suggests arterial oxygen saturation between 91–95% (compared to 85–89%) avoids excess mortality. However, final analyses of data from these trials have not been published, so definitive recommendations are still pending The development of neonatal neurocognitive care visits may improve neurocognitive outcomes in this high-risk group. Long-term follow up to detect and address developmental, learning, behavioral, and social problems is critical for children born at these early gestational ages. The striking similarities in response to extreme prematurity in the lung and brain imply that agents and techniques that benefit one organ are likely to also benefit the other. Finally, since therapy and supportive care continue to change, the outcomes of ELBW infants are ever evolving. Efforts to minimize injury, preserve

  8. Outcomes for extremely premature infants.

    Science.gov (United States)

    Glass, Hannah C; Costarino, Andrew T; Stayer, Stephen A; Brett, Claire M; Cladis, Franklyn; Davis, Peter J

    2015-06-01

    Premature birth is a significant cause of infant and child morbidity and mortality. In the United States, the premature birth rate, which had steadily increased during the 1990s and early 2000s, has decreased annually for 7 years and is now approximately 11.39%. Human viability, defined as gestational age at which the chance of survival is 50%, is currently approximately 23 to 24 weeks in developed countries. Infant girls, on average, have better outcomes than infant boys. A relatively uncomplicated course in the intensive care nursery for an extremely premature infant results in a discharge date close to the prenatal estimated date of confinement. Despite technological advances and efforts of child health experts during the last generation, the extremely premature infant (less than 28 weeks gestation) and extremely low birth weight infant (death and disability with 30% to 50% mortality and, in survivors, at least 20% to 50% risk of morbidity. The introduction of continuous positive airway pressure, mechanical ventilation, and exogenous surfactant increased survival and spurred the development of neonatal intensive care in the 1970s through the early 1990s. Routine administration of antenatal steroids during premature labor improved neonatal mortality and morbidity in the late 1990s. The recognition that chronic postnatal administration of steroids to infants should be avoided may have improved outcomes in the early 2000s. Evidence from recent trials attempting to define the appropriate target for oxygen saturation in preterm infants suggests arterial oxygen saturation between 91% and 95% (compared with 85%-89%) avoids excess mortality; however, final analyses of data from these trials have not been published, so definitive recommendations are still pending. The development of neonatal neurocritical intensive care units may improve neurocognitive outcomes in this high-risk group. Long-term follow-up to detect and address developmental, learning, behavioral, and

  9. Acceleration of ventricular rate by fibrillation associated with the Wolff-Parkinson-White syndrome.

    Science.gov (United States)

    Sheinman, B D; Evans, T

    1982-10-09

    Amiodarone has proved to be a valuable drug in atrial fibrillation associated with the Wolff-Parkinson-White syndrome. When it was administered to a patient with this syndrome in atrial fibrillation, who had previously suffered an inferior myocardial infarction, the ventricular rate accelerated from 170 to 230 beats/minute.This unusual case emphasises the need for full electrophysiological assessment of patients with the Wolff-Parkinson-White syndrome for whom amiodarone treatment is being considered.

  10. Usefulness of 14-Day Holter for Detection of Nonsustained Ventricular Tachycardia in Patients With Hypertrophic Cardiomyopathy.

    Science.gov (United States)

    Weissler-Snir, Adaya; Chan, Raymond H; Adler, Arnon; Care, Melanie; Chauhan, Vijay; Gollob, Michael H; Ziv-Baran, Tomer; Fourey, Dana; Hindieh, Waseem; Rakowski, Harry; Spears, Danna A

    2016-10-15

    Nonsustained ventricular tachycardia (NSVT), defined as ≥3 consecutive ventricular beats at ≥120 beats/min lasting Holter monitoring as part of SCD risk stratification. We sought to assess the difference in diagnostic yield of 14-day Holter monitoring compared to 24-48 hours for the detection of NSVT and to assess the prevalence and characteristics of NSVT in patients with HC with prolonged monitoring. We retrospectively analyzed the 14-day Holter monitors of 77 patients with HC from May 2014 to March 2016. Number of episodes and maximal length and rate on each day were recorded. NSVT was detected in 75.3% of patients during 14-day Holter monitoring. The median number of runs was 2 (range 0 to 26 runs). The median number of beats of the longest run was 10.5 (range 3 to 68 beats) with a mean maximum rate of 159.5 ± 20.8.4 beats/min (range 102 to 203 beats/min). First episodes of NSVT were detected throughout the 14 days, with only 22.5% and 44.8% of the episodes captured within the first 24 and 48 hours of monitoring, respectively. In conclusion, prolonged Holter monitoring revealed ≥1 episode of NSVT in 75% of patients with HC of which Holter monitoring may be superior for SCD risk stratification in HC. However, the high prevalence of NSVT in this population may limit its utility in evaluating the risk for SCD of the individual patient. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. The impact of beat-to-beat variability in optimising the acute hemodynamic response in cardiac resynchronisation therapy

    Directory of Open Access Journals (Sweden)

    Steven Niederer

    2015-12-01

    Conclusion: The beat-to-beat variation in AHR is significant in the context of CRT cut off values. A LOS optimisation offers a novel index to identify the optimal pacing site that accounts for both the mean and variation of the baseline measurement and pacing protocol.

  12. Beat-to-beat variability of QT intervals is increased in patients with drug-induced long-QT syndrome

    DEFF Research Database (Denmark)

    Hinterseer, Martin; Thomsen, Morten Bækgaard; Beckmann, Britt-Maria

    2008-01-01

    Torsades de pointes arrhythmias (TdP) occur by definition in the setting of prolonged QT intervals. Animal models of drug induced Long-QT syndrome (dLQTS) have shown higher predictive value for proarrhythmia with beat-to-beat variability of repolarization duration (BVR) when compared with QT inte...

  13. Postnatal Hyperoxia Exposure Durably Impairs Right Ventricular Function and Mitochondrial Biogenesis.

    Science.gov (United States)

    Goss, Kara N; Kumari, Santosh; Tetri, Laura H; Barton, Greg; Braun, Rudolf K; Hacker, Timothy A; Eldridge, Marlowe W

    2017-05-01

    Prematurity complicates 12% of births, and young adults with a history of prematurity are at risk to develop right ventricular (RV) hypertrophy and impairment. The long-term risk for pulmonary vascular disease, as well as mechanisms of RV dysfunction and ventricular-vascular uncoupling after prematurity, remain poorly defined. Using an established model of prematurity-related lung disease, pups from timed-pregnant Sprague Dawley rats were randomized to normoxia or hyperoxia (fraction of inspired oxygen, 0.85) exposure for the first 14 days of life. After aging to 1 year in standard conditions, rats underwent hemodynamic assessment followed by tissue harvest for biochemical and histological evaluation. Aged hyperoxia-exposed rats developed significantly greater RV hypertrophy, associated with a 40% increase in RV systolic pressures. Although cardiac index was similar, hyperoxia-exposed rats demonstrated a reduced RV ejection fraction and significant RV-pulmonary vascular uncoupling. Hyperoxia-exposed RV cardiomyocytes demonstrated evidence of mitochondrial dysregulation and mitochondrial DNA damage, suggesting potential mitochondrial dysfunction as a cause of RV dysfunction. Aged rats exposed to postnatal hyperoxia recapitulate many features of young adults born prematurely, including increased RV hypertrophy and decreased RV ejection fraction. Our data suggest that postnatal hyperoxia exposure results in mitochondrial dysregulation that persists into adulthood with eventual RV dysfunction. Further evaluation of long-term mitochondrial function is warranted in both animal models of premature lung disease and in human adults who were born preterm.

  14. Metoprolol in acute myocardial infarction reduces ventricular arrhythmias both in the early stage and after the acute event.

    Science.gov (United States)

    Rehnqvist, N; Olsson, G; Erhardt, L; Ekman, A M

    1987-06-01

    Fifty three of the 5778 patients included in the MIAMI (Metoprolol in Acute Myocardial Infarction) trial were investigated with long-term ECG recordings in order to evaluate the effect of acute beta-blockade on premature ventricular complexes in and after acute myocardial infarction. Twenty five patients were given placebo and 28 metoprolol in a double-blind randomized fashion for 15 days. After this period the patients were put on open beta-blockade without breaking individual study codes. The mean number of premature ventricular complexes during the inclusion day (day 0) was the same in the two groups. The median numbers were also similar in the two groups: 190 and 154 in the placebo and metoprolol groups, respectively. Metoprolol significantly reduced the median number of premature ventricular complexes in the randomized period. The median numbers on days 1, 2 and 15 were 146, 101, 84 in the placebo group and 73, 59 and 10 in the metoprolol group, respectively (P less than 0.05). Also during the further follow-up, when investigated 1, 3 and 6 months after the infarction, the median number of premature ventricular complexes was lower in the metoprolol group (74, 257, 142 in the placebo group and 7, 5 and 11 in the metoprolol group, P less than 0.05). This indicates that metoprolol treatment in the acute phase of myocardial infarction reduces ventricular arrhythmias both in the early stage and also after the acute event.

  15. MODERN PRODUCTS FOR FEEDING PREMATURE BABIES

    Directory of Open Access Journals (Sweden)

    A. V. Surzhik

    2012-01-01

    Full Text Available In recent decades there has been substantial progress in the technology of premature infants nursing, especially with extremely low birth weight. Adequate feeding is one of the fundamental factors of premature babies nursing. To ensure a premature baby with all necessary components for power saving in breast milk intake, breast milk fortifiers — specifically developed additives that adjust the composition of food for premature babies, are used for more than 20 years (for premature babies receiving breast milk. On the one hand, to preserve all benefits of breastfeeding, on the other — to prevent the deficit development of necessary elements for adequate growth and development of nutrients.

  16. [Forensic importance of premature craniosynostosis].

    Science.gov (United States)

    Fehlow, P

    1991-01-01

    In agreement with Canabis craniosynostosis as a little known organic partial factor of sociopathy is demonstrated. A psychic syndrome of the frontal lobe with increased susceptibility in environmental damages is assumed to be basic disorder. In the criminals of the material sexual offenders were preponderating. Associated craniofacial dysplasias are a risk for psychic maldevelopment. The importance of premature craniosynostocis as a biological risk factor, incidence, diagnostic, indication for an operation, also in the meaning of a neurosurgical "Konflikttherapie" (cosmetical indication) are discussed.

  17. The related research of heart rate turbulence and Heart rate variability in combined hypertensive with Ventricular premature%心率震荡以及心率变异对高血压伴室性早搏的相关性分析

    Institute of Scientific and Technical Information of China (English)

    张雪梅; 郑春华; 魏友平; 高招波; 张春花; 范剑峰; 万明勇; 熊旭花

    2011-01-01

    Objective To investigate the related research of heart rate turbulence and Heart rate variability in com bined hypertensive w ith V entricular prem ature .M ethods 217 case w ere selected flan June 2008 to January 2010 in our hospital,patients divided into 0 ccasional ventricular prem ature group and frequent ventricular prem ature group according to whether patients with ventricular pran ature ,and choose 80 healthy people as control group .R ecords of 1he differences of H RT ,H RV ' s index .R esults Com pare of the resultbetween each groups found 1hat occasional group and frequent group' s TO and TS has statistically differences with control group , P≤0 .05o The frequentgroup's T0and TS has statistically differences with occasbnal group, P≤0 .05 .occasbnal group and frequent group's SDNN ,T1 lover 1han control group, P≤0 .05 .occasbnal group and frequent group' s T0、TS、SDNN、T1 positive rate significant higher 1han 1he control group, P≤0 .05 .frequent group's T0、TS、SDNN、T1 positive rate higher 1han occasbnal group .C onclusbn Frequent ventricular prem ature group patient' s autonan ic nervous systen function dsm aged serbus ,H RT and H RT canbe used as evaluation indexes for can bined hypertensive w ith V entricular prem ature.%目的 观察心率震荡以及心率变异对高血压伴室性早搏的相关性分析.方法 患者收集我院2008年6月至2010年1月的原发性高血压患者共217例,患者根据有无伴发室性早搏分为偶发室早组,频发室早组,并另外选健康人群80例作为对照组.记录各组HRV、HRT的各项指标的差异.结果 各组结果之间对比中发现,偶发组、频发组的TO、TS与对照组相比差异有统计学意义,P≤0.05.频发组的TO、TS与偶发组对比差异有统计学意义,P≤0.05.偶发组、频发组的SDNN、T1低于对照组,结果有统计学意义,P≤0.05.偶发组、频发组的TO、TS、SDNN、T1的阳性率明显高于对照组,P≤0.05.

  18. Noninvasive continuous beat-to-beat radial artery pressure via TL-200 applanation tonometry.

    Science.gov (United States)

    Dueck, Ron; Goedje, Oliver; Clopton, Paul

    2012-04-01

    The Tensys TL-200(®) noninvasive beat-to-beat blood pressure (BP) monitor displays continuous radial artery waveform as well as systolic, mean and diastolic BP from a pressure sensor directly over the radial artery at the wrist. It locates the site of maximal radial pulse signal, determines mean BP from maximal pulse waveform amplitude at optimal artery compression and then derives systolic and diastolic BP. We performed a cross-sectional study of TL-200 BP comparisons with contralateral invasive radial artery (A-Line) BP values in 19 subjects during an average 2.5 h of general anesthesia for a wide range of surgical procedures. Two hundred and fifty random sample pairs/patient resulted in 4,747 systolic, mean and diastolic BP pairs for analysis. A-Line BP ranged from 29 mm Hg diastolic to 211 mm Hg systolic, and heart rate varied between 38 and 210 beats/min. Bland-Altman analysis showed an average 2.3 mm Hg TL-200 versus A-Line systolic BP bias and limits of agreement (1.96 SD) were ± 15.3 mm Hg. Mean BP showed a 2.3 mm Hg TL-200 bias and ± 11.7 mm Hg limits of agreement, while diastolic BP showed a 1.7 mm Hg bias and ± 12.3 mm Hg limits of agreement. Coefficients of determination for TL-200 and A-Line BP regression were r² = 0.86 for systolic, r² = 0.86 for mean, and r² = 80 for diastolic BP, respectively, with no apparent change in correlation at low or high BP. Bland-Altman analysis suggested satisfactory agreement between TL-200 noninvasive beat-to-beat BP and invasive A-Line BP. Paired TL-200/A-Line BP comparisons showed a high coefficient of determination.

  19. Effect of oral alcohol on left ventricular ejection fraction, volumes, and segmental wall motion in normals and in patients with recent myocardial infarction.

    Science.gov (United States)

    Gould, L; Gopalaswamy, C; Yang, D; Patel, D; Kim, B S; Patel, C; Becker, W H

    1985-11-01

    A first-pass nuclear angiogram and a multiple-gated acquisition study were obtained in 10 normal physicians and in 10 patients with a 7-to-10 day old transmural myocardial infarction. After the scan the subjects drank 2 oz. of whiskey. After 60 minutes, the multiple-gated acquisition study was repeated. In the normal group the left ventricular ejection fraction was 68% before and 72% after alcohol. The left ventricular end-diastolic volume increased from 89 to 97 ml while the left ventricular end-systolic volume decreased from 29 to 27 ml. The stroke volume rose from 61 to 70 ml/beat (p less than 0.05). The cardiac output increased from 4.0 to 5.0 l/min (p less than 0.05). In the infarction group, the left ventricular ejection fraction was 58% before and 56% after alcohol administration. The left ventricular end-diastolic volume fell from 111 to 96 ml, while the left ventricular end-systolic volume declined from 50 to 44 ml. The stroke volume fell from 61 to 52 ml/beat, while the cardiac output fell from 4.5 to 3.8 l/min. In the left ventricular infarction zones, alcohol produced in 9 of the 10 cardiac patients a decline in the left ventricular regional ejection fraction. In the normal group, alcohol produced no significant changes in the regional ejection fraction. The normal and the postinfarction patients responded differently to alcohol.

  20. Usefulness of ventricular endocardial electric reconstruction from body surface potential maps to noninvasively localize ventricular ectopic activity in patients

    Science.gov (United States)

    Lai, Dakun; Sun, Jian; Li, Yigang; He, Bin

    2013-06-01

    As radio frequency (RF) catheter ablation becomes increasingly prevalent in the management of ventricular arrhythmia in patients, an accurate and rapid determination of the arrhythmogenic site is of important clinical interest. The aim of this study was to test the hypothesis that the inversely reconstructed ventricular endocardial current density distribution from body surface potential maps (BSPMs) can localize the regions critical for maintenance of a ventricular ectopic activity. Patients with isolated and monomorphic premature ventricular contractions (PVCs) were investigated by noninvasive BSPMs and subsequent invasive catheter mapping and ablation. Equivalent current density (CD) reconstruction (CDR) during symptomatic PVCs was obtained on the endocardial ventricular surface in six patients (four men, two women, years 23-77), and the origin of the spontaneous ectopic activity was localized at the location of the maximum CD value. Compared with the last (successful) ablation site (LAS), the mean and standard deviation of localization error of the CDR approach were 13.8 and 1.3 mm, respectively. In comparison, the distance between the LASs and the estimated locations of an equivalent single moving dipole in the heart was 25.5 ± 5.5 mm. The obtained CD distribution of activated sources extending from the catheter ablation site also showed a high consistency with the invasively recorded electroanatomical maps. The noninvasively reconstructed endocardial CD distribution is suitable to predict a region of interest containing or close to arrhythmia source, which may have the potential to guide RF catheter ablation.

  1. Changes in autonomic activity preceding onset of nonsustained ventricular tachycardia

    Science.gov (United States)

    Osaka, M.; Saitoh, H.; Sasabe, N.; Atarashi, H.; Katoh, T.; Hayakawa, H.; Cohen, R. J.

    1996-01-01

    Background: The triggering role of the autonomic nervous system in the initiation of ventricular tachycardia has not been established. To investigate the relationship between changes in autonomic activity and the occurrence of nonsustained ventricular tachycardia (NSVT) we examined heart rate variability (HRV) during the 2-hour period preceding spontaneous episodes of NSVT. Twenty-four subjects were identified retrospectively as having had one episode of NSVT during 24-hour Holter ECC recording. Methods: We measured the mean interval between normal heats (meanRR), the standard deviation of the intervals between beats (SD), the percentage of counts of sequential intervals between normal beats with a change of >50 ms (%RR50), the logarithms of low- and high-frequency spectral components (lnLF, lnHF) of HRV for sequential 10-minute segments preceding NSVT. The correlation dimension (CDim) of HRV was calculated similarly for sequential 20-minute segments. We assessed the significance of the time-course change of each marker over the 120-minute period prior to NSVT onset. Results: MeanRR (P parasympathetic activity, perhaps in conjunction with an increase in sympathetic activity, may trigger NSVT.

  2. Exercise-induced polymorphic ventricular tachycardia in adults without structural heart disease.

    Science.gov (United States)

    Tan, Justin Hong-Jie; Scheinman, Melvin M

    2008-04-15

    Patients with catecholaminergic polymorphic ventricular tachycardia present at a young age with exercise-induced ventricular arrhythmias (VAs) and may have a positive family history. We describe 8 patients who presented with exercise-induced symptoms as adults, have a negative family history, and responded to beta-blocker therapy. The study evaluated exercise treadmill electrocardiographic data from patients referred for exercise-induced VA. Inclusion criteria consisted of development of bidirectional, pleomorphic, or polymorphic ventricular tachycardia with exercise, adult age at first onset, negative family history, and no evidence of structural heart disease. We correlated VA configurations with respect to heart rate before and after beta-blocker therapy. Patients displayed a pattern of increasing ventricular complexity with increasing heart rate. The appropriate beta blocker (n = 7) or calcium channel blocker (n = 1) was defined as the dose that resulted in control of symptoms. Three patients showed suppression of VA with sinus tachycardia at peak heart rate. Six patients had decreased VA defined as absence of higher complexity arrhythmias. With drug therapy, average heart rate associated with premature ventricular complex couplets/triplets increased, whereas duration and complexity of premature ventricular complexes decreased. One patient had an automatic implantable cardiac defibrillator placed but has had no discharges from the device since starting the appropriate beta blocker. In conclusion, these patients appear to respond well to beta-blocker or calcium channel blocker therapy with decreased ectopic complexity and an increased heart rate threshold for inducing VA.

  3. On-Pump Beating Coronary Artery Bypass in High Risk Coronary Patients

    Directory of Open Access Journals (Sweden)

    Abbas Afrasiabirad

    2015-01-01

    Full Text Available Background: There are some conflicting results with Conventional Coronary Artery Bypass Grafts (CCABG with arrested heart in coronary high-risk patients. Moreover, performing off-pump CABG in these cases may be associated with serious complications. The objective of this study is to evaluate the efficacy of the on-pump beating CABG (OPBCABG in coronary high-risk patients in comparison with the conventional methods. Methods: In a prospective research study, 3000 off-pump CABG patients were considered during June 2003 to December 2011. Among these, 157 patients with one or more of the following risk factors were included for OPBCABG; severe left main stenosis, early post-acute myocardial infarction with ongoing chest pain, unstable angina, intractable ventricular arrhythmia, post complicated coronary intervention and severe left ventricular dysfunction. These patients were compared with 157 similar patients undergone CCABG with aortic cross clamp before 2003. Results: Preoperative patient characteristics revealed no significant differences between the two groups. The patients’ mean age and number of grafts were 57 years and 3 per patient respectively. Hospital mortality was 3.2% and 9% in OPBCABG and CCABG groups, respectively (P<0.001. Preoperative myocardial infarction, requirement of inotropic agents and intraaortic balloon pump, renal dysfunction and prolonged ventilation time were significantly higher in CCABG group. Conclusion: Our results suggest that OPBCABG is effective in coronary high-risk patients and significantly reduces mortality and the incidence of perioperative MI and other major complications.

  4. Anatomical configurations associated with posthemorrhagic hydrocephalus among premature infants with intraventricular hemorrhage.

    Science.gov (United States)

    Tully, Hannah M; Wenger, Tara L; Kukull, Walter A; Doherty, Dan; Dobyns, William B

    2016-11-01

    OBJECTIVE Intraventricular hemorrhage (IVH) is a complication of prematurity often associated with ventricular dilation, which may resolve over time or progress to posthemorrhagic hydrocephalus (PHH). This study investigated anatomical factors that could predispose infants with IVH to PHH. METHODS The authors analyzed a cohort of premature infants diagnosed with Grade III or IV IVH between 2004 and 2014. Using existing ultrasound and MR images, the CSF obstruction pattern, skull shape, and brain/skull ratios were determined, comparing children with PHH to those with resolved ventricular dilation (RVD), and comparing both groups to a set of healthy controls. RESULTS Among 110 premature infants with Grade III or IV IVH, 65 (59%) developed PHH. Infants with PHH had more severe ventricular dilation compared with those with RVD, although ranges overlapped. Intraventricular CSF obstruction was observed in 36 (86%) of 42 infants with PHH and 0 (0%) of 18 with RVD (p < 0.001). The distribution of skull shapes in infants with PHH was similar to those with RVD, although markedly different from controls. No significant differences in supratentorial brain/skull ratio were observed; however, the mean infratentorial brain/skull ratio of infants with PHH was 5% greater (more crowded) than controls (p = 0.006), whereas the mean infratentorial brain/skull ratio of infants with RVD was 8% smaller (less crowded) than controls (p = 0.004). CONCLUSIONS Among premature infants with IVH, intraventricular obstruction and infratentorial crowding are strongly associated with PHH, further underscoring the need for brain MRI in surgical planning. Prospective studies are required to determine which factors are cause and which are consequence, and which can be used to predict the need for surgical intervention.

  5. Conditional control of quantum beats in a cavity QED system

    CERN Document Server

    Norris, D G; Orozco, L A; 10.1088/1742-6596/274/1/012143

    2011-01-01

    We probe a ground-state superposition that produces a quantum beat in the intensity correlation of a two-mode cavity QED system. We mix drive with scattered light from an atomic beam traversing the cavity, and effectively measure the interference between the drive and the light from the atom. When a photon escapes the cavity, and upon detection, it triggers our feedback which modulates the drive at the same beat frequency but opposite phase for a given time window. This results in a partial interruption of the beat oscillation in the correlation function, that then returns to oscillate.

  6. Investigation of beat-waves generation with high efficiency

    Science.gov (United States)

    Song, W.; Shi, Y. C.; Deng, Y. Q.; Zhu, X. X.; Zhang, Z. Q.; Hu, X. G.

    2013-10-01

    A method for generating high power beating radio-frequency wave with high conversion efficiency is proposed. Based on Cherenkov radiation, two longitudinal resonant modes are excited simultaneously and interacted with intense electron beam synchronously. An experiment was carried out and beat-waves with an average power of about 2.3 GW, frequencies of 9.29 GHz and 10.31 GHz, and efficiency of about 40% were obtained. Through controlling the electron energy, the amplitude proportions of the two resonant modes are altered, and different beat-wave patterns are formed.

  7. Investigation of beat-waves generation with high efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Song, W.; Shi, Y. C.; Deng, Y. Q.; Zhu, X. X.; Zhang, Z. Q.; Hu, X. G. [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi' an, Shanxi 710024 (China)

    2013-10-21

    A method for generating high power beating radio-frequency wave with high conversion efficiency is proposed. Based on Cherenkov radiation, two longitudinal resonant modes are excited simultaneously and interacted with intense electron beam synchronously. An experiment was carried out and beat-waves with an average power of about 2.3 GW, frequencies of 9.29 GHz and 10.31 GHz, and efficiency of about 40% were obtained. Through controlling the electron energy, the amplitude proportions of the two resonant modes are altered, and different beat-wave patterns are formed.

  8. Left ventricular apical diseases.

    Science.gov (United States)

    Cisneros, Silvia; Duarte, Ricardo; Fernandez-Perez, Gabriel C; Castellon, Daniel; Calatayud, Julia; Lecumberri, Iñigo; Larrazabal, Eneritz; Ruiz, Berta Irene

    2011-08-01

    There are many disorders that may involve the left ventricular (LV) apex; however, they are sometimes difficult to differentiate. In this setting cardiac imaging methods can provide the clue to obtaining the diagnosis. The purpose of this review is to illustrate the spectrum of diseases that most frequently affect the apex of the LV including Tako-Tsubo cardiomyopathy, LV aneurysms and pseudoaneurysms, apical diverticula, apical ventricular remodelling, apical hypertrophic cardiomyopathy, LV non-compaction, arrhythmogenic right ventricular dysplasia with LV involvement and LV false tendons, with an emphasis on the diagnostic criteria and imaging features. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s13244-011-0091-6) contains supplementary material, which is available to authorized users.

  9. "'Jackin’ for Beats'": DJing for Citation Critique

    Directory of Open Access Journals (Sweden)

    Todd Craig

    2013-10-01

    Full Text Available A challenge in teaching English composition is helping students envision plagiarism as “borrowing” – showing love to author(s and/or text(s that further their argument(s, versus “stealing” – biting someone’s style and words. Alastair Pennycook (1996 and Sarah Wakefield (2006 have contributed pieces to the elaborate plagiarism/citation puzzle, while Houston Baker situated the hip-hop DJ in seminal text Black Studies, Rap and the Academy (1993. Merging these moments introduces critical questions: Did Diddy invent “the remix” or become the illest beat-biter ever? How did DJ/Producers Pete Rock and Large Professor pay homage to previous musical genres to further hip-hop remix production without just taking 4-8 bar samples, copying sources and claiming unethical ownership? And how can this discussion provide students a window into citation conversations? This article will remix these “texts” to introduce the idea of DJ Rhetoric to discuss plagiarism. Through the lens of the hip-hop DJ in writing classrooms, one can foster an appreciation of the difference between “love and theft” in student citation. This article will couple examples from hip-hop music/culture while simultaneously remixing interviews from various hip-hop DJ/producers to help answer these difficult questions.

  10. Selective particle capture by asynchronously beating cilia

    Science.gov (United States)

    Ding, Yang; Kanso, Eva

    2015-12-01

    Selective particle filtration is fundamental in many engineering and biological systems. For example, many aquatic microorganisms use filter feeding to capture food particles from the surrounding fluid, using motile cilia. One of the capture strategies is to use the same cilia to generate feeding currents and to intercept particles when the particles are on the downstream side of the cilia. Here, we develop a 3D computational model of ciliary bands interacting with flow suspended particles and calculate particle trajectories for a range of particle sizes. Consistent with experimental observations, we find optimal particle sizes that maximize capture rate. The optimal size depends nonlinearly on cilia spacing and cilia coordination, synchronous vs. asynchronous. These parameters affect the cilia-generated flow field, which in turn affects particle trajectories. The low capture rate of smaller particles is due to the particles' inability to cross the flow streamlines of neighboring cilia. Meanwhile, large particles have difficulty entering the sub-ciliary region once advected downstream, also resulting in low capture rates. The optimal range of particle sizes is enhanced when cilia beat asynchronously. These findings have potentially important implications on the design and use of biomimetic cilia in processes such as particle sorting in microfluidic devices.

  11. Feathering collisions in beating reed simulation

    Science.gov (United States)

    Smyth, Tamara; Abel, Jonathan S.; Smith, Julius O.

    2003-10-01

    Pressure controlled valves are the primary sound production mechanisms for woodwind and brass musical instruments, as well as for many bioacoustic vocal systems such as the larynx and syrinx (the vocal organ in birds). During sound production, air flow sets a reed or membrane into motion creating a variable height in the valve channel and, potentially, periodically closing the channel completely. Depending on how this event is handled, an abrupt termination of air flow between open and closed states can cause undesirable discontinuities and inaccuracies in a discrete-time simulation-particularly at relatively low audio sampling rates. A solution was developed by re-examining the behavior of the differential equation governing volume flow through a pressure-controlled valve, paying particular attention to this rather troublesome transition. A closed-form solution for the time evolution of volume flow is given and used to derive an update for volume flow. The result is a smoother, more accurate, and nearly alias-free transition from open to closed. ``Feathered collisions'' of this nature can refine the sound quality produced by the numerical simulation of beating reeds, such as in clarinets, at typical audio sampling rates.

  12. ECG manifestations of left ventricular electrical remodeling.

    Science.gov (United States)

    Estes, E Harvey

    2012-01-01

    Research and thinking about the electrocardiographic manifestations of left ventricular hypertrophy has been constrained by a limited conceptual model of the process: heart disease produces chamber enlargement (increased mass), which in turn produces an altered electrocardiogram. The process is much more complex than can be represented in this simple model. A more robust and intricate model is proposed, in which heart (and vascular) disease causes structural changes, electrical changes, biochemical changes, and others, all of which interact to produce electrical remodeling of ventricular myocardium. This electrical remodeling results in a variety of ECG changes. All of these changes interact, leading to an altered clinical course, and to premature death. It is suggested that research, based on this model, can provide new clues to the processes involved, and improve the prediction of clinical outcomes. New directions in research, in recording equipment, and in organizational activities are suggested to test this new model, and to improve the usefulness of the electrocardiogram as a research and diagnostic tool.

  13. Premature birth and diseases in premature infants: common genetic background?

    Science.gov (United States)

    Hallman, Mikko

    2012-04-01

    It has been proposed that during human evolution, development of obligate bipedalism, narrow birth canal cross-sectional area and the large brain have forced an adjustment in duration of pregnancy (scaling of gestational age; Plunkett 2011). Children compared to other mammals are born with proportionally small brains (compared to adult brains), suggesting shortening of pregnancy duration during recent evolution. Prevalence of both obstructed delivery and premature birth is still exceptionally high. In near term infants, functional maturity and viability is high, and gene variants predisposing to respiratory distress syndrome (RDS) are rare. Advanced antenatal and neonatal treatment practices during the new era of medicine allowed survival of also very preterm infants (gestation premature birth. Specific genes associating with diseases in preterm infants may also contribute to the susceptibility to preterm birth. Understanding and applying the knowledge of genetic interactions in normal and abnormal perinatal-neonatal development requires large, well-structured population cohorts, studies involving the whole genome and international interdisciplinary collaboration.

  14. [Premature ejaculation: pills or sexology?].

    Science.gov (United States)

    Wisard, M; Audette, N

    2008-03-26

    Premature ejaculation (PE) is a frequent male sexual complaint that affects 20 to 30% of men. The exact aetiology is unknown: psychological/behavioristic and biogenic etiologies have been proposed. The introduction of selective serotonin reuptake inhibitors (SSRI) was revolutionary in the medical treatment of PE. However precautions should be taken because of potential adverse side effects. There is no clear consensus as to whether SSRI may represent an eventual cure of PE or will be required for life. The sexocorporal approach is an other treatment of PE, but convincing scientific treatment data are also lacking.

  15. Positional moulding in premature hydrocephalics.

    Directory of Open Access Journals (Sweden)

    Kumar R

    2002-04-01

    Full Text Available Seven premature hydrocephalics presenting with lambdoid positional moulding (LPM were reviewed. All were treated for hydrocephalus secondary to aqueductal stenosis, Dandy Walker Syndrome and infection. Parenchymal hemorrhage, intraventricular bleed, cortical atrophy, septal agenesis, cortical anomalies and subdural hygroma were the other common associations. These children did not show expected improvement in their higher mental functions at 6 months to 5.4 years of follow-up, following the management of hydrocephalus. It was not the LPM but associated intracranial anomalies, which were most probably responsible for their poor outcome. The differentiation from posterior plagiocephaly is also highlighted.

  16. Metabolic bone disease of prematurity

    Directory of Open Access Journals (Sweden)

    Stacy E. Rustico, MD

    2014-09-01

    Full Text Available Metabolic bone disease (MBD of prematurity remains a significant problem for preterm, chronically ill neonates. The definition and recommendations for screening and treatment of MBD vary in the literature. A recent American Academy of Pediatrics Consensus Statement may help close the gap in institutional variation, but evidence based practice guidelines remain obscure due to lack of normative data and clinical trials for preterm infants. This review highlights mineral homeostasis physiology, current recommendations in screening and monitoring, prevention and treatment strategies, and an added perspective of a bone health team serving a high volume referral neonatal intensive care center.

  17. Current therapies for premature ejaculation.

    Science.gov (United States)

    Gur, Serap; Kadowitz, Philip J; Sikka, Suresh C

    2016-07-01

    Premature ejaculation (PE) subjectively affects 20-30% of men globally. Until recently, understanding of PE was hampered by the absence of a widely accepted definition, paucity of evidence-based clinical studies, and the absence of an appropriate animal model. Here, we elaborate on the current definition of PE, its pathogenesis, currently available therapies, and future treatment prospects. Most treatments for PE are 'off-label' and include selective serotonin reuptake inhibitors (SSRIs), topical anesthetics, tramadol, and phosphodiesterase type 5 (PDE5) inhibitors. Such knowledge of the benefit and limitations of each treatment will help to direct future drug design and formulations.

  18. After Stroke, 'Blue' Light May Help Beat the Blues

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_163731.html After Stroke, 'Blue' Light May Help Beat the Blues Akin ... a danger for people recovering from a debilitating stroke. But new research suggests that tweaking a rehabilitation ...

  19. Modulation of attosecond beating in resonant two-photon ionization

    CERN Document Server

    Galán, Álvaro J; Martín, Fernando

    2014-01-01

    We present a theoretical study of the photoelectron attosecond beating at the basis of RABBIT (Reconstruction of Attosecond Beating By Interference of Two-photon transitions) in the presence of autoionizing states. We show that, as a harmonic traverses a resonance, its sidebands exhibit a peaked phase shift as well as a modulation of the beating frequency itself. Furthermore, the beating between two resonant paths persists even when the pump and the probe pulses do not overlap, thus providing a sensitive non-holographic interferometric means to reconstruct coherent metastable wave packets. We characterize these phenomena quantitatively with a general finite-pulse analytical model that accounts for the effect of both intermediate and final resonances on two-photon processes, at a negligible computational cost. The model predictions are in excellent agreement with those of accurate ab initio calculations for the helium atom in the region of the N=2 doubly excited states.

  20. Drug Beats Steroids for Controlling Blood Vessel Inflammation in Study

    Science.gov (United States)

    ... html Drug Beats Steroids for Controlling Blood Vessel Inflammation in Study With tocilizumab's approval, there's an alternative ... treating the most common form of blood vessel inflammation known as giant cell arteritis, a new study ...

  1. Botox Beats Implant for Urinary Incontinence in Women

    Science.gov (United States)

    ... html Botox Beats Implant for Urinary Incontinence in Women But both have side effects that may affect ... 2016 TUESDAY, Oct. 4, 2016 (HealthDay News) -- For women with bladder incontinence who haven't been helped ...

  2. Best Way to Beat Back Zika a Matter of Debate

    Science.gov (United States)

    ... fullstory_162423.html Best Way to Beat Back Zika a Matter of Debate Analysis found conflicting evidence ... methods for controlling the mosquitoes that can transmit Zika and other diseases. The researchers, from the University ...

  3. Mercury Beating Heart: Modifications to the Classical Demonstration

    Science.gov (United States)

    Najdoski, Metodija; Mirceski, Valentin; Petrusevski, Vladimir M.; Demiri, Sani

    2007-01-01

    The mercury beating heart (MBH) is a commonly performed experiment, which is based on varying oxidizing agents and substituting other metals for iron. Various modified versions of the classical demonstration of the experiment are presented.

  4. Taming microwave plasma to beat thermodynamics in CO2 dissociation

    NARCIS (Netherlands)

    van Rooij, G.; van den Bekerom, D.; N. den Harder,; Minea, T.; G. Berden,; Bongers, W.; Engeln, R.; Graswinckel, M.; Zoethout, E.; M. C. M. van de Sanden,

    2015-01-01

    The strong non-equilibrium conditions provided by the plasma phase offer the opportunity to beat traditional thermal process energy efficiencies via preferential excitation of molecular vibrations. Simple molecular physics considerations are presented to explain potential dissociation pathways in a

  5. Modeling ventricular function during cardiac assist: does time-varying elastance work?

    Science.gov (United States)

    Vandenberghe, Stijn; Segers, Patrick; Steendijk, Paul; Meyns, Bart; Dion, Robert A E; Antaki, James F; Verdonck, Pascal

    2006-01-01

    The time-varying elastance theory of Suga et al. is widely used to simulate left ventricular function in mathematical models and in contemporary in vitro models. We investigated the validity of this theory in the presence of a left ventricular assist device. Left ventricular pressure and volume data are presented that demonstrate the heart-device interaction for a positive-displacement pump (Novacor) and a rotary blood pump (Medos). The Novacor was implanted in a calf and used in fixed-rate mode (85 BPM), whereas the Medos was used at several flow levels (0-3 l/min) in seven healthy sheep. The Novacor data display high beat-to-beat variations in the amplitude of the elastance curve, and the normalized curves deviate strongly from the typical bovine curve. The Medos data show how the maximum elastance depends on the pump flow level. We conclude that the original time-varying elastance theory insufficiently models the complex hemodynamic behavior of a left ventricle that is mechanically assisted, and that there is need for an updated ventricular model to simulate the heart-device interaction.

  6. Ventricular performance during exercise in patients with chronic obstructive pulmonary disease (COPD)

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Iwao; Akashiba, Tsuneto; Horie, Takashi (Nihon Univ., Tokyo (Japan). School of Medicine)

    1992-01-01

    We assessed ventricular performance during exercise in 16 chronic obstructive pulmonary disease (COPD) patients and 8 normal control subjects by means of radionuclide equilibrium angiography using technetium-99m as a tracer. Supine exercise on a bicycle ergometer was performed until symptom-limited exhaustion. Data were accumulated for 300 heart beats at rest and 150 heart beats during exercise. We used the standard voxel count method to calculate the ventricular volumes. Age, FEV{sub 1.0}%, %VC, PaO{sub 2} and PaCO{sub 2} of the COPD patients were 63{+-}8 yr, 46{+-}11%, 69{+-}18%, 68{+-}11 Torr and 44{+-}7 Torr (mean{+-}SD), respectively. Systolic dysfunction of both the left and right ventricles was well confirmed in the present study. In 12 patients who also underwent hemodynamic studies, resting total pulmonary vascular resistance index (TPVRI) and mean pulmonary artery pressure (P-barpa) significantly correlated with right ventricular end-systolic volume index (RVESVI) obtained by RI angiography; {gamma}=0.769 (p<0.01) and {gamma}=0.631 (p<0.05), respectively. A significant relationship was also observed between left ventricular dysfunction and the degree of hypercapnia. In response to exercise testing, 10 of 16 patients exhibited insufficient augmentation of stroke volume, and both left and right end-diastolic volumes decreased in half of 10 patients. It is suggested that cardiac function may be disturbed by mechanical factors such as pulmonary hyperinflation in COPD patients. (author).

  7. Beat relationships between orbital periodicities in insolation theory

    Science.gov (United States)

    Stothers, Richard B.

    1987-01-01

    Variations in insolation are examined in terms of beat relationships. The relations between eccentricity periods, precessional parameters, and obliquity periods are analyzed. Beat periods are calculated and compared with orbital periodicities from Berger's (1978) series expansions. It is noted that the data, which correlate eccentricity, obliquity, and precessional-parameter periods, are applicable to the study of orbital periodicities in time-series analyses of long-term climatic records.

  8. Human auditory steady state responses to binaural and monaural beats.

    Science.gov (United States)

    Schwarz, D W F; Taylor, P

    2005-03-01

    Binaural beat sensations depend upon a central combination of two different temporally encoded tones, separately presented to the two ears. We tested the feasibility to record an auditory steady state evoked response (ASSR) at the binaural beat frequency in order to find a measure for temporal coding of sound in the human EEG. We stimulated each ear with a distinct tone, both differing in frequency by 40Hz, to record a binaural beat ASSR. As control, we evoked a beat ASSR in response to both tones in the same ear. We band-pass filtered the EEG at 40Hz, averaged with respect to stimulus onset and compared ASSR amplitudes and phases, extracted from a sinusoidal non-linear regression fit to a 40Hz period average. A 40Hz binaural beat ASSR was evoked at a low mean stimulus frequency (400Hz) but became undetectable beyond 3kHz. Its amplitude was smaller than that of the acoustic beat ASSR, which was evoked at low and high frequencies. Both ASSR types had maxima at fronto-central leads and displayed a fronto-occipital phase delay of several ms. The dependence of the 40Hz binaural beat ASSR on stimuli at low, temporally coded tone frequencies suggests that it may objectively assess temporal sound coding ability. The phase shift across the electrode array is evidence for more than one origin of the 40Hz oscillations. The binaural beat ASSR is an evoked response, with novel diagnostic potential, to a signal that is not present in the stimulus, but generated within the brain.

  9. Towards T1-limited magnetic resonance imaging using Rabi beats

    CERN Document Server

    Fedder, H; Rempp, F; Wolf, T; Hemmer, P; Jelezko, F; Wrachtrup, J

    2010-01-01

    Two proof-of-principle experiments towards T1-limited magnetic resonance imaging with NV centers in diamond are demonstrated. First, a large number of Rabi oscillations is measured and it is demonstrated that the hyperfine interaction due to the NV's 14N can be extracted from the beating oscillations. Second, the Rabi beats under V-type microwave excitation of the three hyperfine manifolds is studied experimentally and described theoretically.

  10. Towards T 1-limited magnetic resonance imaging using Rabi beats

    Science.gov (United States)

    Fedder, H.; Dolde, F.; Rempp, F.; Wolf, T.; Hemmer, P.; Jelezko, F.; Wrachtrup, J.

    2011-03-01

    Two proof-of-principle experiments toward T 1-limited magnetic resonance imaging with NV centers in diamond are demonstrated. First, a large number of Rabi oscillations is measured and it is demonstrated that the hyperfine interaction due to the NV's 14N can be extracted from the beating oscillations. Second, the Rabi beats under V-type microwave excitation of the three hyperfine manifolds is studied experimentally and described theoretically.

  11. Teflon-buttressed sutures plus pericardium patch repair left ventricular rupture caused by radiofrequency catheter ablation

    Science.gov (United States)

    Cao, Hao; Zhang, Qi; He, Yanzhong; Feng, Xiaodong; Liu, Zhongmin

    2016-01-01

    Abstract Background: Cardiac rupture often occurs after myocardial infarction or chest trauma with a high mortality rate. However, left ventricular rupture caused by radiofrequency catheter ablation (RFCA) is extremely rare. Methods: We describe a case of a 61-year-old male who survived from left ventricular rupture caused by a RFCA procedure for frequent ventricular premature contractions. Surgical exploration with cardiopulmonary bypass (CPB) was performed when the signs of cardiac tamponade developed 7 hours after the ablation surgery. Results: Teflon-buttressed sutures of the tear in the left ventricular posterolateral wall and pericardium patch applied to the contusion region on the wall repaired the rupture safely and effectively. Conclusion: Timely surgical intervention under CPB facilitated the survival of the patient. Teflon-buttressed sutures plus pericardium patch achieved the successful repair of the rupture. PMID:27661047

  12. Premature temporal theta (PT theta).

    Science.gov (United States)

    Hughes, J R; Fino, J J; Hart, L A

    1987-07-01

    A distinctive pattern called premature temporal theta (PT theta) was studied in 436 infants, ranging in age from 24 to 46 weeks. The pattern is seen in early prematurity, maximizes at 29-31 weeks and then diminishes and disappears near term. Usually the pattern is found independently on both temporal areas, but with a right-sided preference. Patients without PT theta or with a significantly low amount had either neurological or non-neurological (medical) conditions. With age there is a tendency for an increase in frequency and a decrease in amplitude. Five different peaks in the amount of this pattern are seen at approximately every month. Unilateral PT theta tends to be seen in older babies, more often on the right side and with an abnormal EEG. An abnormal EEG is usually associated with a delay in both the appearance and disappearance of this wave form. PT theta is also associated mainly with REM or active sleep. A polynomial rather than an exponential or power function best describes these data with changes of age. PT theta may arise from the inferior temporal gyrus and/or especially the transverse gyrus.

  13. Aortic and mitral valve surgery on the beating heart is lowering cardiopulmonary bypass and aortic cross clamp time.

    Science.gov (United States)

    Gersak, Borut; Sutlic, Zeljko

    2002-01-01

    The concept of cardiac surgery on the beating heart is acceptable rationale for the cardiac surgery in the next millenium. Beating heart (off-pump) coronary artery bypass grafting (CABG) techniques have led us to consider the possibility for performing the aortic and mitral valve surgery (mitral valve repairs and replacements - with or without CABG) on the beating heart with the technique of retrograde oxygenated coronary sinus perfusion. We used the technique of retrograde oxygenated blood coronary sinus perfusion in 78 patients (Group All) - (36 patients were with extremely low ejection fraction (Group X) - 62% of whom were in New York Heart Association (NYHA) class 4 and 34% of whom were in NYHA class 3). The procedures for the patients were: aortic, mitral and tricuspid valve surgery, in combination with CABG in ischemic patients. CABG was done in all the cases off-pump. In addition, we performed a case match study for 37 patients with good ejection fraction (51.65 +/- 11.88) (Beating Heart Group) operated on the beating heart with most appropriate group of patients (No. 37) operated in our institutions on arrested heart (ejection fraction 51.07 +/- 12.93) (Arrested Heart Group). The case match selection criteria were: gender, left ventricular ejection fraction, atrial fibrillation, hypertension, pulmonary hypertension, and diabetes. The selected beating heart group and selected arrested heart groups were without statistically significant differences for the mentioned criteria. There were statistically significant differences between Beating Heart Group and Arrested Heart Group in the duration of Cardiopulmonary Bypass Time (69.35 +/- 13.52 min. versus 93.59 +/- 28.54 min.), pHeart Group were lower. There was no statistical difference in complication rate for both the groups for: sternal infection, bleeding, death, atrial fibrillation, AV block and neurological complications. The total early mortality for all the patients was 5.1% (4 out of 78) - for the group

  14. Dental anesthetic management of a patient with ventricular arrhythmias.

    Science.gov (United States)

    Miller, R A; Siegelman, L I

    1998-01-01

    During routine deep sedation for endodontic therapy, a dentist-anesthesiologist observed premature ventricular contractions (PVCs) on a 62-yr-old woman's electrocardiogram (EKG) tracing. The dentist was able to complete the root canal procedure under intravenous (i.v.) sedation without any problems. The dentist-anesthesiologist referred the patient for medical evaluation. She was found to be free from ischemic cardiac disease with normal ventricular function. The patient was cleared to continue her dental treatment with deep sedation. She subsequently continued to undergo dental treatment with deep intravenous sedation without incident, although her EKG exhibited frequent PVCs, up to 20 per minute, including couplets and episodes of trigeminy. This article will review indications for medical intervention, antiarrhythmic medications, and anesthetic interventions for perioperative PVCs.

  15. Heart rate modulates the slow enhancement of contraction due to sudden left ventricular dilation.

    Science.gov (United States)

    Tucci, P J; Murad, N; Rossi, C L; Nogueira, R J; Santana, O

    2001-05-01

    In isovolumic blood-perfused dog hearts, left ventricular developed pressure (DP) was recorded while a sudden ventricular dilation was promoted at three heart rate (HR) levels: low (L: 52 +/- 1.7 beats/min), intermediate (M: 82 +/- 2.2 beats/min), and high (H: 117 +/- 3.5 beats/min). DP increased instantaneously with chamber expansion (Delta(1)DP), and another continuous increase occurred for several minutes (Delta(2)DP). HR elevation did not alter Delta(1)DP (32.8 +/- 1.6, 33.6 +/- 1.5, and 34.3 +/- 1.2 mmHg for L, M, and H, respectively), even though it intensified Delta(2)DP (17.3 +/- 0.9, 20.7 +/- 1.0, and 26.8 +/- 1.2 mmHg for L, M, and H, respectively), meaning that the treppe phenomenon enhances the length dependence of the contraction component related to changes in intracellular Ca(2+) concentration. Frequency increments reduced the half time of the slow response (82 +/- 3.6, 67 +/- 2.6, and 53 +/- 2.0 s for L, M, and H, respectively), while the number of beats included in half time increased (72 +/- 2.9, 95 +/- 2.9, and 111 +/- 3.2 beats for L, M, and H, respectively). HR modulation of the slow response suggests that L-type Ca(2+) channel currents and/or the Na(+)/Ca(2+) exchanger plays a relevant role in the stretch-triggered Ca(2+) gain when HR increases in the canine heart.

  16. Positive airway pressure improves nocturnal beat-to-beat blood pressure surges in obesity hypoventilation syndrome with obstructive sleep apnea.

    Science.gov (United States)

    Carter, Jason R; Fonkoue, Ida T; Grimaldi, Daniela; Emami, Leila; Gozal, David; Sullivan, Colin E; Mokhlesi, Babak

    2016-04-01

    Positive airway pressure (PAP) treatment has been shown to have a modest effect on ambulatory blood pressure (BP) in patients with obstructive sleep apnea (OSA). However, there is a paucity of data on the effect of PAP therapy on rapid, yet significant, BP swings during sleep, particularly in obesity hypoventilation syndrome (OHS). The present study hypothesizes that PAP therapy will improve nocturnal BP on the first treatment night (titration PAP) in OHS patients with underlying OSA, and that these improvements will become more significant with 6 wk of PAP therapy. Seventeen adults (7 men, 10 women; age 50.4 ± 10.7 years, BMI 49.3 ± 2.4 kg/m(2)) with OHS and clinically diagnosed OSA participated in three overnight laboratory visits that included polysomnography and beat-to-beat BP monitoring via finger plethysmography. Six weeks of PAP therapy, but not titration PAP, lowered mean nocturnal BP. In contrast, when nocturnal beat-to-beat BPs were aggregated into bins consisting of at least three consecutive cardiac cycles with a >10 mmHg BP surge (i.e., Δ10-20, Δ20-30, Δ30-40, and Δ>40 mmHg), titration, and 6-wk PAP reduced the number of BP surges per hour (time × bin, P < 0.05). PAP adherence over the 6-wk period was significantly correlated to reductions in nocturnal systolic (r = 0.713, P = 0.001) and diastolic (r = 0.497, P = 0.043) BP surges. Despite these PAP-induced improvements in nocturnal beat-to-beat BP surges, 6 wk of PAP therapy did not alter daytime BP. In conclusion, PAP treatment reduces nocturnal beat-to-beat BP surges in OHS patients with underlying OSA, and this improvement in nocturnal BP regulation was greater in patients with higher PAP adherence.

  17. Repair of left ventricular aneurysm during off-pump coronary artery bypass surgery

    Institute of Scientific and Technical Information of China (English)

    YU Yang; GU Cheng-xiong; WEI Hua; LIU Rui; CHEN Chang-cheng; FANG Ying

    2005-01-01

    Background Acute myocardial infarction can result in left ventricular aneurysm, which may in turn cause congestive heart failure, ventricular arrhythmia and thromboembolic events. This study evaluates results achieved with a modified linear closure of left ventricular aneurysms during off-pump coronary artery bypass surgery.Methods From January 2001 to May 2004, 75 patients were operated on for nonruptured, postinfarctional, left ventricular aneurysm during off-pump coronary artery bypass surgery. Repair was completed on the beating heart to minimize ischaemia and allow assessment of wall function and viability to guide closure. All patients presented with symptoms of angina and congestive heart failure or ventricular arrhythmia. The majority (75%) of the patients were in NYHA functional class Ⅲ or Ⅳ. Preoperative ejection fraction was 26%±9%. The mean left ventricular, end diastolic diameter was (57.5±7.1) mm. The ventricular preoperative and postoperative performances were compared. χ2 test and Student's t test were used to analyse the outcomes. A P value less than 0.05 was considered significant.Results Hospital mortality was 1.3% (1/75). Coronary artery bypass was performed with an average of (3.3±1.2) grafts per patient. At the time of followup, all the patients had no symptoms. The mean NYHA class and ejection fraction increased significantly (P<0.001). The mean left ventricular, end diastolic diameter decreased significantly (P<0.001). Conclusions Surgical closure of left ventricular aneurysm can be performed during off-pump coronary artery bypass. The operation is associated with a low inhospital mortality and morbidity. A postoperative improvement in the early term cardiac functions and symptoms and quality of life was documented, increasing our expectations of an increased long-term survival.

  18. Adaptive control with self-tuning for non-invasive beat-by-beat blood pressure measurement.

    Science.gov (United States)

    Nogawa, Masamichi; Ogawa, Mitsuhiro; Yamakoshi, Takehiro; Tanaka, Shinobu; Yamakoshi, Ken-ichi

    2011-01-01

    Up to now, we have successfully carried out the non-invasive beat-by-beat measurement of blood pressure (BP) in the root of finger, superficial temporal and radial artery based on the volume-compensation technique with reasonable accuracy. The present study concerns with improvement of control method for this beat-by-beat BP measurement. The measurement system mainly consists of a partial pressurization cuff with a pair of LED and photo-diode for the detection of arterial blood volume, and a digital self-tuning control method. Using healthy subjects, the performance and accuracy of this system were evaluated through comparison experiments with the system using a conventional empirically tuned PID controller. The significant differences of BP measured in finger artery were not showed in systolic (SBP), p=0.52, and diastolic BP (DBP), p=0.35. With the advantage of the adaptive control with self-tuning method, which can tune the control parameters without disturbing the control system, the application area of the non-invasive beat-by-beat measurement method will be broadened.

  19. 心电图碎裂QRS波预测急性心肌梗死室性心律失常的价值探讨%To explore the value of fragmented QRS to predict ventricular arrhythmic events in patients with acute myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    郭勇娟; 项美香

    2011-01-01

    Objective The purpose of this study was to determine whether fQRS is associated with increased ventricular arrhythmic event in patients with Acute ST- elevation Myocardial Infarction.Methods 12-lead ECG, 24h-Holter monitoring and biochemical markers detection were performed in sixty cases with acute ST-elevation myocardial infarction, which were divided into two groups[fQRS group and nonfQRS group]according to Fragmented QRS (fQRS) on 12-lead ECG.Then ventricular arrhythmic events were analyzed.Results Ventricular premature beats (24 h, 3140 +555 vs 1226 + 142, P <0.01) and the incidence of complex ventricular arrhythmic events(34.4% vs 10.7%, P <0.05) in fQRS group were significantly higher than that in non- fQRS group.Conclusions Fragmented QRS may be used to predict ventricular arrhythmic events in patients with acute ST- elevation myocardial infarction.%目的 探讨心电图ST段抬高型急性心肌梗死患者碎裂QRS波(fragmented QRS complex,fQRS)预测急性心肌梗死室性心律失常的价值。方法在急性心肌梗死后8周左右对每一位研究对象均进行常规心电图和动态心电图检查及生化标志物检测,根据常规心电图fQRS的有无,将研究对象分为fQRS组和非fQRS组,分别统计室性心律失常的发生率。结果fQRS组24h室性早搏的发生数明显高于非fQRS组(3140±555 vs 1226±142,P<0.01),复杂室性心律失常的发生率明显高于非fQRS组(34.4%vs 10.7%,P<0.05)。结论心电图12导联fQRS波可能可预测ST段抬高型急性心肌梗死患者室性心律失常事件的发生。

  20. Determination of right ventricular volumes during aortic surgery.

    Science.gov (United States)

    Van der Linden, P; Gilbart, E; Engelman, E; de Rood, M; Vincent, J L

    1989-06-01

    The aim of the present study was to evaluate right ventricular (RV) preload by measurements of right ventricular volumes during aortic clamping and unclamping. Nine patients (aged 67 +/- 9 years) undergoing infrarenal aortic aneurysmectomy were monitored with a pulmonary artery catheter equipped with a fast-response thermistor, allowing determination of RV volumes by the thermodilution technique. Anesthesia consisted of a continuous infusion of alfentanil and 50% N2O. Aortic clamping resulted in a significant decrease in cardiac index (CI) and a significant increase in systemic vascular resistance (SVR). There was no significant change in right ventricular ejection fraction (RVEF) (from 35% +/- 6% to 33% +/- 8%) in the presence of a significant decrease in stroke index (from 37.2 +/- 9.8 to 31.1 +/- 10.0 mL/beat/m2, P less than 0.05), indicating a significant decrease in RV end-diastolic volume (from 106 +/- 17 to 92 +/- 19 mL, P less than 0.01). There were no significant changes in cardiac filling pressures. Aortic unclamping was associated with a significant increase in CI and a significant decrease in SVR. There were no significant changes in cardiac filling pressures, RVEF, or RV volumes. Measurements of RV volumes indicated that aortic clamping resulted in a decrease in RV preload, which is usually not demonstrated by measurements of right atrial pressure alone.

  1. Beating of wives: a cross-cultural perspective.

    Science.gov (United States)

    Campbell, J C

    1985-01-01

    This paper reports a more in-depth analysis of wife beating from a cross-cultural perspective. As background for the analysis, the methodological, operationalization, and measurement in previous cross-cultural research on wife beating is examined. Subsequently, a review of findings from these studies and the theoretical explanations from selected disciplines are presented as the basis of selection of variables expected to affect the presence and severity of wife abuse in a given culture. These variables are then examined with evidence from female perspective ethnographies on eleven different societies. This cross-cultural analysis of wife beating has illuminated more issues of methodology and variations of patterns than it has answered any questions about what may increase the frequency and severity of wife-beating in a given culture. It is possible that the beating of wives is a personal expression of hostility against women that may be expressed in addition to, or instead of, institutionalized aggression toward women in that culture. As such, wife beating can take many forms. It can be an indication of manhood, a means of personal control, a reflection of personal animosity, and an expression of sexual jealousy. These personal forms would be paralleled by societal expression such as gang rape, control of women by exclusion from the public sphere, general hostility between sexes, and the virtue of women becoming an issue of extended family and community honor. In conclusion, the importance of the variables is summarized and directions for future cross-cultural research on wife beating are suggested.

  2. Experience of valve replacement under mild hypothermia on pump-beating heart:an analysis of 800 cases

    Institute of Scientific and Technical Information of China (English)

    陈柏成; 肖颖彬; 陈林; 钟前进; 王学锋; 周骐; 易广兵

    2004-01-01

    Objective: To assess the outcome of valve replacement under mild hypothermia on pump-beating heart and to discuss the risk factors of cardiac valve surgery. Methods: In the period from November 1997 to May 2003, a total of 800cases of valve replacement were carried out in our institute. The clinical data were reviewed and the technique of mild hypothermia and pump-beating heart to replace cardiac valve was described in detail. Results: 800 patients, 308 male and 492female, with age range from 8 to 66 years, weighing 19 to 88 kg, underwent operation. The average cardiopulmonary bypass time was (109.38 ± 40.64) min, the average clamping time of the vena cava was (77.87 ± 27.99) min and the average mechanical ventilation time was (17.78 ± 12.21) h. There were 17 patients died in the early postoperative stage with an early mortality rate of 2.13%. The causes of death were failure in the weaning of extracorporeal circulation in 2 cases, severe low output syndrome in 3 cases, ventricular fibrillation in 3 cases, obstruction of coronary ostium of mechanical prosthetic valve in 1 case, hepatic failure in 2 cases, pulmonary failure in 1 case, multiorgan failure in 4 cases, and prosthetic valve dysfunction in 1 case. Severe postopertive complications occurred in 51 cases (6.375%), which included reexploration because of excessive bleeding in 16 cases (2.0%), lavage of poststemal infection in 2 cases (0.25%), postoperative strike in 7 cases (0.875%), pulmonary failure in 5 cases (0.625%), hepatic failure in 4 cases (0.5%), multiorgan failure in 11 cases (1.375 % ), ventricular arrhythmia in 5 cases (0.625%) and peripheral circulation failure in 1 case(0. 125 % ). Conclusion: Mild hypothermia and pump-beating heart result in satisfying clinical outcome in patients undergoing valve replacement. The integrated sequenced deairing procedure ensures the avoidance of air embolism during operation.Pump-beating heart technique offers a safe and practical option especially in

  3. 7 CFR 29.2290 - Premature primings.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Premature primings. 29.2290 Section 29.2290 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... 21) § 29.2290 Premature primings. Ground leaves harvested before reaching complete growth and...

  4. 28 CFR 51.22 - Premature submissions.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Premature submissions. 51.22 Section 51.22 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) PROCEDURES FOR THE ADMINISTRATION OF... § 51.22 Premature submissions. The Attorney General will not consider on the merits: (a) Any proposal...

  5. Premature infants' health at multiple induced pregnancy.

    Directory of Open Access Journals (Sweden)

    Chernenkov Yu.V.

    2015-09-01

    Full Text Available Objective: to define the risk factors adversely influencing prenatal development at premature birth at use of methods of assisted reproductive technology (ART; to estimate premature' infants health from multiple induced pregnancy according to Perinatal Center of Saratov for last 3 years. Material and Methods. Under supervision there were 139 pregnant women with application ART. 202 children (51 twins were born and 5 triplet babies, from them 83 premature infants born from multiple induced pregnancy have been analyzed. Results. The newborns examined by method ART, were distributed as follows: 22-28 weeks — 19 children; 29-32 weeks — 23; 33-36 weeks — 41. Asphyxia at birth was marked at all premature infants. Respiratory insufficiency at birth is revealed in 87,3% of cases. The most frequent pathologies in premature infants are revealed: neurologic infringements and bronchopulmonary pathology occured at all children, developmental anomaly — 33, 8%, retinopathies in premature infants — 26,5%. The mortality causes include: extreme immaturity, cerebral leukomalacia, IVN 3 degrees. Conclusion. The risk factors, premature birth at application of methods ART are revealed: aged primiparas, pharmacological influence, absence of physiological conditions of prenatal development; multifetation. The high percent of birth of children with ELBW and ULBW is revealed. RDCN with further BPD development, retinopathies in premature infants and CNS defeat is more often occured.

  6. Pulsatile flow in ventricular catheters for hydrocephalus

    Science.gov (United States)

    Giménez, Á.; Galarza, M.; Thomale, U.; Schuhmann, M. U.; Valero, J.; Amigó, J. M.

    2017-05-01

    The obstruction of ventricular catheters (VCs) is a major problem in the standard treatment of hydrocephalus, the flow pattern of the cerebrospinal fluid (CSF) being one important factor thereof. As a first approach to this problem, some of the authors studied previously the CSF flow through VCs under time-independent boundary conditions by means of computational fluid dynamics in three-dimensional models. This allowed us to derive a few basic principles which led to designs with improved flow patterns regarding the obstruction problem. However, the flow of the CSF has actually a pulsatile nature because of the heart beating and blood flow. To address this fact, here we extend our previous computational study to models with oscillatory boundary conditions. The new results will be compared with the results for constant flows and discussed. It turns out that the corrections due to the pulsatility of the CSF are quantitatively small, which reinforces our previous findings and conclusions. This article is part of the themed issue `Mathematical methods in medicine: neuroscience, cardiology and pathology'.

  7. [Premature rupture of membranes and chorioamnionitis].

    Science.gov (United States)

    Lopez Garcia, R

    1988-01-01

    Despite advances in perinatal medicine in the past decade, the diagnosis and treatment of premature rupture of membranes remain controversial. Premature rupture occurs in 2.7-7.0% of pregnancies and most cases occur spontaneously without apparent cause. The disparity in reported rates of premature rupture is due to differences in the definition and diagnostic criteria for premature rupture and lack of comparability in the populations studied. Mexico's National Institute of Perinatology has adopted the definition of the American COllege of Gynecology and Obstetrics which views premature rupture as that occurring before regular uterine contractions that produce cervical dilation. 8.8% of its patients have premature rupture according to this definition. 20% of cases occur before the 36th week of pregnancy. Treatment of rupture occurring before 37 weeks must balance the threat of amniotic infection with the dangers of premature birth. Infections appear more common in low income patient populations. Chorioamnionitis is a serious complication of pregnancy and is the main argument against conservative treatment of premature rupture. The rate of maternal infection is directly related to the time elapsing between rupture of the membranes and birth. The rate increases after the 1st 24 hours and is at least 10 times higher after 72 hours. But recent studies suggest that there is no considerable increase in infection if vaginal explorations are avoided and careful techniques are used in treating the patient. Those who advise conservative treatment believe that prenatal outcomes are better because respiratory disease syndrome due to prematurity is avoided. Conservative management requires a white cell count at least every 24 hours and measurement of pulse, maternal temperature, and fetal heart rate ideally every 4 hours. Perinatal mortality rates due to premature rupture of membranes range from 2.5-50%. The principal causes are respiratory disease syndrome, infection, asphyxia

  8. Human milk for the premature infant

    Science.gov (United States)

    Underwood, Mark A.

    2012-01-01

    Synopsis Premature infants are a heterogeneous group with widely differing needs for nutrition and immune protection with risk of growth failure, developmental delays, necrotizing enterocolitis, and late-onset sepsis increasing with decreasing gestational age and birth weight. Human milk from women delivering prematurely has more protein and higher levels of many bioactive molecules compared to milk from women delivering at term. Human milk must be fortified for small premature infants to achieve adequate growth. Mother’s own milk improves growth and neurodevelopment and decreases the risk of necrotizing enterocolitis and late-onset sepsis and should therefore be the primary enteral diet of premature infants. Donor milk is a valuable resource for premature infants whose mothers are unable to provide an adequate supply of milk, but presents significant challenges including the need for pasteurization, nutritional and biochemical deficiencies and a limited supply. PMID:23178065

  9. [Indications for implantable loop recorders in patients with channelopathies and ventricular tachycardias].

    Science.gov (United States)

    Köbe, Julia; Wasmer, Kristina; Reinke, Florian; Eckardt, Lars

    2016-12-01

    Implantable loop recorders (ILR) do not play a pivotal role in the current guidelines on ventricular arrhythmias except in identifying rhythm-symptom correlations if ventricular arrhythmias are assumed. Before a decision for a pure diagnostic implantable device is made, a thorough arrhythmic risk assessment is of major importance due to the potential lethal outcome of ventricular arrhythmias. Nevertheless, some clinical circumstances exist where long-term monitoring by an ILR may add significant information in electrical heart diseases, in patients with ventricular arrhythmias, or structural heart diseases and a potential risk of ventricular arrhythmias. As medical therapy (β-blocker therapy) plays an important role in long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardias (cpVT), the ILR can be used to control therapy in patients at risk. In electrical diseases without pharmacologic therapeutic options (e. g., Brugada syndrome), the ILR may be used in low-risk patients with atypical syncope as benign faints may occur without association to the underlying disease. Evidence on cardiomyopathies with preserved left ventricular function and nonsustained VT or premature ventricular complexes is scarce. The ILR may also add long-term information on the individual risk in these circumstances. In very rare diseases like infiltrative disease or muscular dystrophies, the ILR may also provide evidence on risk stratification. In summary, ILR in electrical heart diseases and in patients with ventricular tachycardia remains a very individual decision taking into account various clinical, electrocardiographic, and genetic parameters. The following review aims at highlighting possible indications and clinical scenarios for ILR in ventricular tachycardias and electrical heart diseases with-probably debatable-case presentations.

  10. Ventricular Assist Device Support: for Management of Sustained Ventricular Arrhythmias

    OpenAIRE

    2002-01-01

    We describe herein the cases of 2 patients who had ventricular arrhythmias. In one, a short-term biventricular assist device, the ABIOMED BVS 5000, was placed because the patient had sustained ventricular tachycardia and could not be weaned from cardiopulmonary bypass. Excellent hemodynamic support was maintained for several days while the antiarrhythmic therapy was maximized. Sinus rhythm was restored, and the patient was successfully weaned from the ventricular assist device. However, the s...

  11. Acceleration of ventricular rate by amiodarone in atrial fibrillation associated with the Wolff-Parkinson-White syndrome

    Science.gov (United States)

    Sheinman, Bryan D; Evans, Tom

    1982-01-01

    Amiodarone has proved to be a valuable drug in atrial fibrillation associated with the Wolff-Parkinson-White syndrome. When it was administered to a patient with this syndrome in atrial fibrillation, who had previously suffered an inferior myocardial infarction, the ventricular rate accelerated from 170 to 230 beats/minute. This unusual case emphasises the need for full electrophysiological assessment of patients with the Wolff-Parkinson-White syndrome for whom amiodarone treatment is being considered. Imagesp1000-a PMID:6812745

  12. Serial evaluation of left ventricular function by radionuclide ventriculography at rest and during exercise after orthotopic heart transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, A.; Huth, A.; Burger, W.; Kaltenbach, M. (Frankfurt Univ. (Germany). Abt. fuer Kardiologie); Maul, F.D.; Hoer, G. (Frankfurt Univ. (Germany). Abt. fuer Nuklearmedizin); Krause, E. (Frankfurt Univ. (Germany). Abt. fuer Herzgefaesschirurgie)

    1993-02-01

    Discrepant results have previously been reported concerning long-term left ventricular function in the human transplanted heart as assessed by radionuclide ventriculography. In this study, radionuclide ventriculograms were obtained at rest and during exercise in 19 patients <6 months, 7-12 months, 13-24 months and >24 months after transplantation. Ejection fraction decreased significantly from <6 months to 13-24 months after transplantation (rest: 69.1%[+-]9.7% to 56.7%[+-]8.3%, P<0.05; exercise: 70.4%[+-]11.3% to 59%[+-]8%, P<0.05). Heart rate increased significantly during exercise after >2 years (90.2[+-]10.5 beats/min to 103.5[+-]15 beats/min, P<0.05) but not within 6 months after transplantation (98.5[+-]12.8 beats/min to 99.07[+-]15.8 beats/min). Left ventricular end-diastolic volume remained unchanged. Peak filling rate at rest decreased significantly from 4.2[+-]0.96 edv/s<6 months after transplantation to 3.3[+-]0.66 edv/s (P<0.05) 13-24 months and 3.3[+-]0.64 edv/s (P<0.05)>24 months after cardiac transplantation. Exercise peak filling rate did not change significantly. It is concluded that radionuclide ventriculography demonstrates a decrease in systolic left ventricular function in the long-term course after cardiac transplantation. A significant increase in exercise peak heart rate may be due to autonomic reinnervation. Differences in the literature concerning left ventricular function may be due to different observation intervals following cardiac transplantation. (orig.).

  13. Rerouting surgery of cardiac type total anomalous pulmonary venous return in a premature newborn with very low birth weight.

    Science.gov (United States)

    Wu, En-Ting; Huang, Shu-Chien; Wu, Mei-Hwan; Wang, Jou-Kou; Chang, Chung-I

    2007-02-01

    Intracardiac repair for complex congenital heart defects in premature neonates with very low birth weight (VLBW) is still a challenge to pediatric cardiac surgeons. We report the successful rerouting of cardiac type total anomalous pulmonary venous return (TAPVR) in a premature newborn (36th gestational week) with VLBW (1250 g). She had severe hypoxemia and low cardiac output despite medical treatment. Rerouting surgery of TAPVR was performed under deep hypothermia circulatory arrest at the age of 20 days. The sternum was left open and approximated 2 days later. Follow-up echocardiography showed good ventricular function without pulmonary venous obstruction. The endotracheal tube was removed 7 days postoperatively. She was then discharged without complication. In conclusion, with improved cardiopulmonary bypass technique and perioperative care, open heart surgery can be performed in premature newborns with VLBW.

  14. Dynamic Control of Maximal Ventricular Elastance in Conscious Dogs Before and After Pacing-Induced Heart Failure

    Science.gov (United States)

    Chen, Xiaoxiao; Sala-Mercado, Javier A.; Hammond, Robert L.; Kim, Jong-Kyung; McDonald, Phillip J.; Stephenson, Larry W.; Soltani, Soroor; O'Leary, Donal S.; Mukkamala, Ramakrishna

    2010-01-01

    We identified the transfer functions relating beat-to-beat fluctuations in arterial blood pressure to maximal ventricular elastance (ABP→Emax) and beat-to-beat fluctuations in heart rate to Emax (HR→Emax) to characterize the dynamic properties of the arterial ventricular contractility baroreflex and force-frequency relation, respectively, in three conscious dogs before and after pacing-induced heart failure. During the control condition, the average gain value, dominant time constant, and time delay were respectively -0.0374 ml-1, 12.8 sec, and 2 sec for the ABP→Emax transfer function and 0.0137 mmHg/ml-bpm, 1.77 sec, and 0 sec for the HR→Emax transfer function. During the heart failure condition, both transfer functions were markedly depressed. These results are consistent with known physiology and previous studies and provide perhaps the first quantitative information on the dynamic control of Emax during normal closed-loop operation. PMID:19963897

  15. Cardiac output by Doppler echocardiography in the premature baboon: comparison with radiolabeled microspheres.

    Science.gov (United States)

    Kinsella, J P; Morrow, W R; Gerstmann, D R; Taylor, A F; deLemos, R A

    1991-04-01

    Pulsed-Doppler echocardiography (PDE) is a useful noninvasive method for determining left ventricular output (LVO). However, despite increasingly widespread use in neonatal intensive care units, validation studies in prematures with cardiopulmonary disease are lacking. The purpose of this study was to compare radiolabeled microsphere (RLM) and PDE measurements of LVO, using the critically ill premature baboon as a model of the human neonate. Twenty-two paired RLM and PDE measurements of LVO were obtained in 14 animals between 3 and 24 h of age. Average PDE LVO was 152 ml/min/kg (range, 40-258 ml/min/kg) compared to 158 ml/min/kg (range, 67-278 ml/min/kg) measured by RLM. Linear regression analysis of the paired measurements showed good correlation with a slope near unity (gamma = 0.94x + 4.20, r = 0.91, SEE = 25.7 ml). We conclude that PDE determinations of LVO compare well with those measured by RLM in the premature baboon. PDE appears to provide a valid estimate of LVO and should be useful in human prematures with cardiopulmonary distress.

  16. Introduction of multicenter clinical trials for retinopathy of retinopathy: LIGHT-ROP, STOP-ROP and BEAT-ROP%早产儿视网膜病变多中心临床试验介绍—LIGHT-ROP、STOP-ROP和BEAT-ROP

    Institute of Scientific and Technical Information of China (English)

    李蓉; 王雨生

    2012-01-01

    Evidence-based medicine is very important to clinical prevention and treatment tor retinopathy of prematurity(ROP).Although retianl ablation including cryotherapy and laser has been proved to be effective in treating ROP,it can be destructive to the peripheral retina to some extent.Therefore,better and safer therapies are desired.After the two influential clinical trials—" Cryotherapy forretinopathy of prematurity(CRYO-ROP) " and "Early treatment for retinopathy of prematurity study(ET-ROP) ",other significant muhicenter clinical trials has been initiated successively in the United States in order to explore novel therapeutic ways,such as "The effects of light reduction on retinopathy of prematurity (LIGHT-ROP) ","Supplemental therapeutic oxygen for prethreshold retinopathy of prematurity (STOP-ROP)" and " Bevacizumab eliminates the angiogenic threat of retinopathy of prematurity(BEAT-ROP) ".In this article,we reviewed the goals,designs,main results and conclusions of the three trials.%循证医学证据对于临床防治早产儿视网膜病变(ROP)具有重要意义.已证实视网膜消融术(冷冻和激光)治疗ROP有效,但对周边视网膜具有一定的破坏性,因而需要寻找更安全的治疗方法.继“冷冻治疗ROP(CRYO-ROP)”和“早期治疗ROP(ET-ROP)”临床试验之后,美国又先后发起了“减少光照对ROP的效应(LIGHT-ROP)”、“阈值前ROP补充氧疗(STOP-ROP)”和“贝伐单抗消除ROP的血管生成威胁(BEAT-ROP)”等多项重要的多中心临床试验,旨在探索新的治疗途径.本文综述了ROP多中心临床试验LIGHT-ROP、STOP-ROP和BEAT-ROP的目的、试验设计、主要结果和结论.

  17. Psychosocial interventions for premature ejaculation

    Directory of Open Access Journals (Sweden)

    Tamara Melnik

    Full Text Available BACKGROUND: Premature ejaculation (PE is a very common sexual dysfunction among patients, and with varying prevalence estimates ranging from 3% to 20%. Although psychological issues are present in most patients with premature PE, as a cause or as a consequence, research on the effects of psychological approaches for PE has in general not been controlled or randomised and is lacking in long-term follow up. OBJECTIVE: To assess the efficacy of psychosocial interventions for PE. CRITERIA FOR CONSIDERING STUDIES FOR THIS REVIEW: Trials were searched in computerized general and specialized databases, such as: MEDLINE by PubMed (1966 to 2010; PsycINFO (1974 to 2010; EMBASE (1980 to 2010; LILACS (1982 to 2010; the Cochrane Central Register of Controlled Trials (Cochrane Library, 2010; and by checking bibliographies, and contacting manufacturers and researchers. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials evaluating psychosocial interventions compared with different psychosocial interventions, pharmacological interventions, waiting list, or no treatment for PE. DATA COLLECTION AND ANALYSIS: Information on patients, interventions, and outcomes was extracted by at least two independent reviewers using a standard form. The primary outcome measure for comparing the effects of psychosocial interventions to waiting list and standard medications was improvement in IELT (i.e., time from vaginal penetration to ejaculation. The secondary outcome was change in validated PE questionnaires. MAIN RESULTS: In one study behavioral therapy (BT was significantly better than waiting list for duration of intercourse (MD (mean difference 407.90 seconds, 95% CI 302.42 to 513.38, and couples' sexual satisfaction (MD -26.10, CI -50.48 to -1.72. BT was also significantly better for a new functional-sexological treatment (FS (MD 412.00 seconds, 95% CI 305.88 to 518.12, change over time in subjective perception of duration of intercourse (Women: MD 2

  18. Prevention of adenosine A2A receptor activation diminishes beat-to-beat alternation in human atrial myocytes.

    Science.gov (United States)

    Molina, Cristina E; Llach, Anna; Herraiz-Martínez, Adela; Tarifa, Carmen; Barriga, Montserrat; Wiegerinck, Rob F; Fernandes, Jacqueline; Cabello, Nuria; Vallmitjana, Alex; Benitéz, Raúl; Montiel, José; Cinca, Juan; Hove-Madsen, Leif

    2016-01-01

    Atrial fibrillation (AF) has been associated with increased spontaneous calcium release from the sarcoplasmic reticulum and linked to increased adenosine A2A receptor (A2AR) expression and activation. Here we tested whether this may favor atrial arrhythmogenesis by promoting beat-to-beat alternation and irregularity. Patch-clamp and confocal calcium imaging was used to measure the beat-to-beat response of the calcium current and transient in human atrial myocytes. Responses were classified as uniform, alternating or irregular and stimulation of Gs-protein coupled receptors decreased the frequency where a uniform response could be maintained from 1.0 ± 0.1 to 0.6 ± 0.1 Hz; p < 0.01 for beta-adrenergic receptors and from 1.4 ± 0.1 to 0.5 ± 0.1 Hz; p < 0.05 for A2ARs. The latter was linked to increased spontaneous calcium release and after-depolarizations. Moreover, A2AR activation increased the fraction of non-uniformly responding cells in HL-1 myocyte cultures from 19 ± 3 to 51 ± 9 %; p < 0.02, and electrical mapping in perfused porcine atria revealed that adenosine induced electrical alternans at longer cycle lengths, doubled the fraction of electrodes showing alternation, and increased the amplitude of alternations. Importantly, protein kinase A inhibition increased the highest frequency where uniform responses could be maintained from 0.84 ± 0.12 to 1.86 ± 0.11 Hz; p < 0.001 and prevention of A2AR-activation with exogenous adenosine deaminase selectively increased the threshold from 0.8 ± 0.1 to 1.2 ± 0.1 Hz; p = 0.001 in myocytes from patients with AF. In conclusion, A2AR-activation promotes beat-to-beat irregularities in the calcium transient in human atrial myocytes, and prevention of A2AR activation may be a novel means to maintain uniform beat-to-beat responses at higher beating frequencies in patients with atrial fibrillation.

  19. Superresolution measurement of nanofiber diameter by modes beating

    Science.gov (United States)

    Fenton, E. F.; Solano, P.; Hoffman, J. E.; Orozco, L. A.; Rolston, S. L.; Fatemi, F. K.

    2016-05-01

    Nanofibers are becoming an important tool in quantum information technologies for coupling photonics systems to atomic systems. Nondestructive techniques for characterizing these nanofibers prior to integration into an apparatus are desirable. In this work, we probe the light propagating in a fused silica optical nanofiber (750-nm-diameter) by coupling it evanescently to a 6- μm-diameter microfiber that is scanned along the nanofiber length. This technique is capable of observing all possible beat lengths among different propagating modes. The beat lengths are strongly dependent on the nanofiber diameter and refractive index of the fiber. The steep dependence has enabled measurements of the fiber diameter with sub-Angstrom sensitivity. The diameter extracted from the beat length measurements agrees with a measurement made using scanning electron microscopy. Work supported by NSF.

  20. Mechanisms of Beat-to-Beat Regulation of Cardiac Pacemaker Cell Function by Ca2+ Cycling Dynamics

    Science.gov (United States)

    Yaniv, Yael; Stern, Michael D.; Lakatta, Edward G.; Maltsev, Victor A.

    2013-01-01

    Whether intracellular Ca2+ cycling dynamics regulate cardiac pacemaker cell function on a beat-to-beat basis remains unknown. Here we show that under physiological conditions, application of low concentrations of caffeine (2–4 mM) to isolated single rabbit sinoatrial node cells acutely reduces their spontaneous action potential cycle length (CL) and increases Ca2+ transient amplitude for several cycles. Numerical simulations, using a modified Maltsev-Lakatta coupled-clock model, faithfully reproduced these effects, and also the effects of CL prolongation and dysrhythmic spontaneous beating (produced by cytosolic Ca2+ buffering) and an acute CL reduction (produced by flash-induced Ca2+ release from a caged Ca2+ buffer), which we had reported previously. Three contemporary numerical models (including the original Maltsev-Lakatta model) failed to reproduce the experimental results. In our proposed new model, Ca2+ releases acutely change the CL via activation of the Na+/Ca2+ exchanger current. Time-dependent CL reductions after flash-induced Ca2+ releases (the memory effect) are linked to changes in Ca2+ available for pumping into sarcoplasmic reticulum which, in turn, changes the sarcoplasmic reticulum Ca2+ load, diastolic Ca2+ releases, and Na+/Ca2+ exchanger current. These results support the idea that Ca2+ regulates CL in cardiac pacemaker cells on a beat-to-beat basis, and suggest a more realistic numerical mechanism of this regulation. PMID:24094396

  1. Mechanisms of beat-to-beat regulation of cardiac pacemaker cell function by Ca²⁺ cycling dynamics.

    Science.gov (United States)

    Yaniv, Yael; Stern, Michael D; Lakatta, Edward G; Maltsev, Victor A

    2013-10-01

    Whether intracellular Ca(2+) cycling dynamics regulate cardiac pacemaker cell function on a beat-to-beat basis remains unknown. Here we show that under physiological conditions, application of low concentrations of caffeine (2-4 mM) to isolated single rabbit sinoatrial node cells acutely reduces their spontaneous action potential cycle length (CL) and increases Ca(2+) transient amplitude for several cycles. Numerical simulations, using a modified Maltsev-Lakatta coupled-clock model, faithfully reproduced these effects, and also the effects of CL prolongation and dysrhythmic spontaneous beating (produced by cytosolic Ca(2+) buffering) and an acute CL reduction (produced by flash-induced Ca(2+) release from a caged Ca(2+) buffer), which we had reported previously. Three contemporary numerical models (including the original Maltsev-Lakatta model) failed to reproduce the experimental results. In our proposed new model, Ca(2+) releases acutely change the CL via activation of the Na(+)/Ca(2+) exchanger current. Time-dependent CL reductions after flash-induced Ca(2+) releases (the memory effect) are linked to changes in Ca(2+) available for pumping into sarcoplasmic reticulum which, in turn, changes the sarcoplasmic reticulum Ca(2+) load, diastolic Ca(2+) releases, and Na(+)/Ca(2+) exchanger current. These results support the idea that Ca(2+) regulates CL in cardiac pacemaker cells on a beat-to-beat basis, and suggest a more realistic numerical mechanism of this regulation.

  2. Search for cardiac calcium cycling gene mutations in familial ventricular arrhythmias resembling catecholaminergic polymorphic ventricular tachycardia

    Directory of Open Access Journals (Sweden)

    Toivonen Lauri

    2009-02-01

    Full Text Available Abstract Background Catecholaminergic polymorphic ventricular tachycardia (CPVT is a severe inherited cardiac disorder caused by mutations predominantly in the ryanodine receptor (RyR2 gene. We sought to identify mutations in genes affecting cardiac calcium cycling in patients with CPVT and in less typical familial exercise-related ventricular arrhythmias. Methods and Results We recruited 33 consecutive patients with frequent ventricular premature complexes (VPCs without structural heart disease and often history of syncope or sudden death in family. Sixteen of the patients featured a phenotype typical of CPVT. In 17 patients, VPCs emerged also at rest. Exercise stress test and echocardiography were performed to each patient and 232 family members. Familial background was evident in 42% of cases (n = 14. We sequenced all the coding exons of the RyR2, FKBP1B, ATP2A2 and SLC8A1 genes from the index patients. Single channel recordings of a mutant RyR2 were performed in planar lipid bilayers. Two novel RyR2 missense mutations (R1051P and S616L and two RyR2 exon 3 deletions were identified, explaining 25% of the CPVT phenotypes. A rare variant (N3308S with open probabilities similar to the wild type channels in vitro, was evident in a patient with resting VPCs. No disease-causing variants were detectable in the FKBP1B, ATP2A2 or SLC8A1 genes. Conclusion We report two novel CPVT-causing RyR2 mutations and a novel RyR2 variant of uncertain clinical significance in a patient with abundant resting VPCs. Our data also strengthen the previous assumption that exon 3 deletions of RyR2 should screened for in CPVT and related phenotypes.

  3. The load-response of the flagellar beat

    CERN Document Server

    Klindt, Gary S; Wanger, Christian; Friedrich, Benjamin M

    2016-01-01

    Cilia and flagella exhibit regular bending waves that perform mechanical work on the surrounding fluid, to propel cellular swimmers and pump fluids inside organisms. Here, we quantify a force-velocity relationship of the beating flagellum, by exposing flagellated \\emph{Chlamydomonas} cells to controlled microfluidic flows. A simple theory of flagellar limit-cycle oscillations, calibrated by measurements in the absence of flow, reproduces this relationship quantitatively. We derive a link between the chemo-mechanical efficiency of the flagellar beat and its ability to synchronize to oscillatory flows.

  4. Can We Learn to Beat the Best Stock

    CERN Document Server

    Borodin, A; Gogan, V; 10.1613/jair.1336

    2011-01-01

    A novel algorithm for actively trading stocks is presented. While traditional expert advice and "universal" algorithms (as well as standard technical trading heuristics) attempt to predict winners or trends, our approach relies on predictable statistical relations between all pairs of stocks in the market. Our empirical results on historical markets provide strong evidence that this type of technical trading can "beat the market" and moreover, can beat the best stock in the market. In doing so we utilize a new idea for smoothing critical parameters in the context of expert learning.

  5. Sexuality in pregnancy and premature labour.

    Science.gov (United States)

    Georgakopoulos, P A; Dodos, D; Mechleris, D

    1984-09-01

    The relation of sexual behaviour during pregnancy to the initiation of labour was investigated in 358 patients of whom 58 were delivered after premature labour and 300 were delivered spontaneously at term. In all patients the mean weekly coital frequency and the frequency of orgasm were investigated by means of a retrospective questionnaire. There was no significant difference in coital or orgasmic frequency between the women who had a premature labour and those who had a spontaneous delivery at term. This was also true when those having premature labour were divided into those starting labour with ruptured membranes and those starting with contractions.

  6. Acute appendicitis in a premature baby

    Energy Technology Data Exchange (ETDEWEB)

    Beluffi, Giampiero; Alberici, Elisa [Department of Radiodiagnosis, Section of Paediatric Radiology, IRCCS Policlinico S. Matteo, Piazzale Golgi 2, 27100 Pavia PV (Italy)

    2002-07-01

    A case of acute appendicitis in a premature baby in whom diagnosis was suggested on plain films of the abdomen is presented. In this baby air in a hollow viscus suspected of being an enlarged appendix was the clue to diagnosis. The diagnostic dilemma of this rare and life-threatening condition in premature babies and newborns is underlined. The relevance of different imaging modalities and of different findings in this age group is discussed. Awareness of this rare condition and possible differential diagnosis in newborns and premature babies is stressed. (orig.)

  7. [Premature newborn: a case presentation].

    Science.gov (United States)

    Pastor Rodríguez, Jesús David; Pastor Bravo, María Del Mar; López García, Visitación; Cotes Teruel, María Isabel; Mellado, Jesús Eulogio; Cárceles, José Jara

    2010-01-01

    A case is presented of a premature newborn of 27 weeks gestation and weighing 420 grams who was delivered as a result of a maternal pre-eclampsia and retarded intra-uterine growth. During the 125 days of hospitalisation, an individual care plan based on the Virginia Henderson model was devised and applied to both the child and her parents using NANDA diagnostics, interventions according to the NIC classification, and the expected results according to the NOC classification. The Marjory Gordon functional patterns were used for the initial assessment. By applying the pre-term newborn (PTNB) plan, all their needs were provided and were modified throughout the hospital stay, with new needs that were added to the established ones. These required a continuous assessment with the subsequent adapting of the care plan. Likewise, the care required by the parents varied from the initial grief due to the possible loss of their child to learning the alarm signs and the home care that their child would need. The child was finally discharged weighing 2900 grams and with normal neurological and psychomotor development, although with a lower weight appropriate to her age. Currently, at 2 years old, the child has a normal neurological and psychomotor development, but with weight and size lower than the P(3) percentile. She requires speech therapy treatment due to paralysis of the right vocal cord.

  8. Psychosexual therapy for premature ejaculation.

    Science.gov (United States)

    Althof, Stanley E

    2016-08-01

    Premature ejaculation (PE) is a male sexual dysfunction that creates considerable anguish for the man, his partner and their relationship. PE is not one disorder but includes the four subtypes (lifelong, acquired, natural and subjective) each with unique psychological concerns and issues. Psychological treatment for men and couples with PE addresses sexual skills/techniques but also focuses on issues of self-esteem, performance anxiety and interpersonal conflict. The outcome studies for psychotherapy alone are difficult to interpret and compare because of poor methodological design (lack of control groups, small sample size, poor outcome measures and lack of follow-up). However, the few studies that surmount these methodological hurdles suggest that psychological intervention offers men and couples a promising treatment option. Combination pharmaco- and psychotherapy is the most promising intervention for lifelong and acquired PE and offers superior efficacy to drug alone. This is because men and couples learn sexual skills, address the intrapsychic, interpersonal and cognitive issues that precipitate and maintain the dysfunction.

  9. The epidemiology of premature ejaculation.

    Science.gov (United States)

    Saitz, Theodore Robert; Serefoglu, Ege Can

    2016-08-01

    Vast advances have occurred over the past decade with regards to understanding the epidemiology, pathophysiology and management of premature ejaculation (PE); however, we still have much to learn about this common sexual problem. As a standardized evidence-based definition of PE has only recently been established, the reported prevalence rates of PE prior to this definition have been difficult to interpret. As a result, a large range of conflicting prevalence rates have been reported. In addition to the lack of a standardized definition and operational criteria, the method of recruitment for study participation and method of data collection have obviously contributed to the broad range of reported prevalence rates. The new criteria and classification of PE will allow for continued research into the diverse phenomenology, etiology and pathogenesis of the disease to be conducted. While the absolute pathophysiology and true prevalence of PE remains unclear, developing a better understanding of the true prevalence of the disease will allow for the completion of more accurate analysis and treatment of the disease.

  10. [Sexological intervention on premature ejaculation].

    Science.gov (United States)

    San Martín Blanco, C

    2014-07-01

    Strategies, recommendations and techniques proposed by sex therapy for intervention on premature ejaculation, have represented for nearly four decades the most effective model of intervention in this sexual dysfunction, which currently is complemented by the efficacy of dapoxetine drug treatment. Clinical experience and recent studies support that combined intervention offers the best therapeutic results. In addition in sex therapy, etiologic diagnosis is obtained from the analysis of the interrelationship of the couple. Diagnostic and therapeutic intervention has to be always centered in the relationship, so the techniques and resources must be applied with the expectation of being implemented in the sexual interaction. It will therefore be the relationship that receive treatment, even if medication is used for one of the members of the couple. On the other hand, this model of intervention can be implemented by a professional with training, although not necessarily a specialist. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Medicina Rural y Generalista (SEMERGEN). All rights reserved.

  11. Medical therapy for premature ejaculation

    Science.gov (United States)

    Mohee, Amar; Eardley, Ian

    2011-01-01

    Premature ejaculation (PE) is a common male sexual dysfunction. Advances in PE research have been hampered owing to a nonstandardized definition of PE, until the definition by the International Society of Sexual Medicine (ISSM) in 2009. Once the diagnosis of PE is established through a thorough history, a variety of medical therapies is available, including tricyclic antidepressants, selective serotonin reuptake inhibitors (SSRIs), centrally acting opiates, phosphodiesterase 5 inhibitors and topical desensitizing creams. Most of these treatments increase the intravaginal ejaculation latency time (IELT) and patient satisfaction scores, with the most convincing evidence for SSRIs and topical creams. Daily SSRIs such as paroxetine, although efficacious, do have a substantial and prolonged side effect profile. Dapoxetine, which is a on-demand SSRI, is the only licensed drug for the treatment of PE, increasing IELT by a factor of 2.5 to 3 with limited and tolerable side effects. In the near future, the topical aerosol PSD502 is due to be licensed for the treatment of PE, increasing IELT by up to a factor of 6 but having minimal local and negligible systemic side effects. PMID:22046199

  12. Ventricular assist device support for management of sustained ventricular arrhythmias.

    Science.gov (United States)

    Fasseas, Panayotis; Kutalek, Steven P; Samuels, Fania L; Holmes, Elena C; Samuels, Louis E

    2002-01-01

    We describe herein the cases of 2 patients who had ventricular arrhythmias. In one, a short-term biventricular assist device, the ABIOMED BVS 5000, was placed because the patient had sustained ventricular tachycardia and could not be weaned from cardiopulmonary bypass. Excellent hemodynamic support was maintained for several days while the antiarrhythmic therapy was maximized. Sinus rhythm was restored, and the patient was successfully weaned from the ventricular assist device. However, the substrate for the arrhythmia persisted, and a recurrence, 1 week later, resulted in the patient's death. In the 2nd patient, the use of an implantable left ventricular assist device was successful in temporarily alleviating the ventricular tachycardia associated with ischemic cardiomyopathy. However, after 2 days of device assistance, the patient experienced a recurrence of the tachycardia, which degenerated into ventricular fibrillation with a marked deterioration in the patient's hemodynamics. The arrhythmia persisted despite multiple attempts at external cardioversion, and internal cardioversion and placement of an automatic implantable cardioverter-defibrillator were necessary. This treatment, along with repeated boluses of amiodarone, led to successful suppression of the arrhythmias, and the patient eventually underwent transplantation. The mechanical hemodynamic support of the circulation by ventricular assist devices was effective in supporting these 2 patients who had sustained ventricular arrhythmias.

  13. Postpartal right ventricular thrombosis.

    Science.gov (United States)

    Velicki, Lazar; Milosavljević, Aleksandar; Majin, Marijan; Vujin, Bojan; Kovacević, Pavle

    2008-11-01

    The discovery of an intracardial mass in patients presents a serious diagnostic dilemma. The differential diagnosis of this condition may seem abundant, but myxomas and intracardial thrombosis are the most frequent diagnoses. A connection between pregnancy and the presence of thrombosis has been documented frequently. Normal pregnancy leads to changes of the coagulative and fibrinolytic status toward a hypercoagulable condition which has its own physiological justification (the risk of blood loss decreases during labor). The case of a patient suffering from postpartal right ventricular thrombosis, which was successfully resolved by surgery as described in this contribution, demonstrates the value of a multidisciplinary approach.

  14. Effects of beating-heart and arrested heart intracardiac procedure on the inflammation induced by cardiopulmonary bypass

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhe; XIAO Ying-Bin; CHEN Lin; WANG Xue-feng; ZHONG Qian-jin

    2005-01-01

    Objective:To evaluate the effects of beating-heart and arrested heart intracardiac procedure on the expression of tumor necrosis factor alpha (TNF-α) mRNA in myocardium.Methods: Thirty congenital ventricular septal defect (VSD) patients aged from 5 to 10 years old were randomly divided into 2 groups equally. Group A underwent traditional arrested-heart intracardiac procedures; group B underwent beating-heart procedures. Specimens of myocardium were obtained at the onset (baseline) and the end of cardiopulmonary bypass (CPB) for the determination of TNF-α mRNA. Concentration of TNF-α was respectively measured after anesthetic induction (T1), 20 min after the beginning of CPB (T2), at the end of CPB (T3) and 6, 12, 24 h after CPB (T4-6) in all patients. After separating polymorphonuclear leucocyte (PMN), we distilled nuclear protein and mensurated the activation of nuclear factor-κB (NF-κB) by electrophoretic mobility shift assay (EMSA). Results:Compared with baseline, the expression of TNF-α mRNA significantly increased in both groups (P<0.05). TNF-α mRNA level of group A was significantly higher than that of group B at the end of CPB (P<0.05). The plasma concentration of TNF-α and neutrophil NF-κB activity in group A was significantly higher than that of group B at T4-6 (P<0.05). Conclusion:Compared with traditional arrested CPB, beating heart intracadiac procedure can effectively reduce the expression and release of TNF-α; it will benefit the protection of pediatric myocardial during CPB.

  15. The brain responses to different frequencies of binaural beat sounds on QEEG at cortical level.

    Science.gov (United States)

    Jirakittayakorn, Nantawachara; Wongsawat, Yodchanan

    2015-01-01

    Beat phenomenon is occurred when two slightly different frequency waves interfere each other. The beat can also occur in the brain by providing two slightly different frequency waves separately each ear. This is called binaural beat. The brain responses to binaural beat are in discussion process whether the brain side and the brain area. Therefore, this study aims to figure out the brain responses to binaural beat by providing different binaural beat frequencies on 250 carrier tone continuously for 30 minutes to participants and using quantitative electroencephalography (QEEG) to interpret the data. The result shows that different responses appear in different beat frequency. Left hemisphere dominance occur in 3 Hz beat within 15 minutes and 15 Hz beat within 5 minutes. Right hemisphere dominance occurs in 10 Hz beat within 25 minute. 6 Hz beat enhances all area of the brain within 10 minutes. 8 Hz and 25 Hz beats have no clearly responses while 40 Hz beat enhances the responses in frontal lobe. These brain responses can be used for brain modulation application to induce the brain activity in further studies.

  16. Stroma cell-derived factor-1α signaling enhances calcium transients and beating frequency in rat neonatal cardiomyocytes.

    Directory of Open Access Journals (Sweden)

    Ielham Hadad

    Full Text Available Stroma cell-derived factor-1α (SDF-1α is a cardioprotective chemokine, acting through its G-protein coupled receptor CXCR4. In experimental acute myocardial infarction, administration of SDF-1α induces an early improvement of systolic function which is difficult to explain solely by an anti-apoptotic and angiogenic effect. We wondered whether SDF-1α signaling might have direct effects on calcium transients and beating frequency.Primary rat neonatal cardiomyocytes were culture-expanded and characterized by immunofluorescence staining. Calcium sparks were studied by fluorescence microscopy after calcium loading with the Fluo-4 acetoxymethyl ester sensor. The cardiomyocyte enriched cellular suspension expressed troponin I and CXCR4 but was vimentin negative. Addition of SDF-1α in the medium increased cytoplasmic calcium release. The calcium response was completely abolished by using a neutralizing anti-CXCR4 antibody and partially suppressed and delayed by preincubation with an inositol triphosphate receptor (IP3R blocker, but not with a ryanodine receptor (RyR antagonist. Calcium fluxes induced by caffeine, a RyR agonist, were decreased by an IP3R blocker. Treatment with forskolin or SDF-1α increased cardiomyocyte beating frequency and their effects were additive. In vivo, treatment with SDF-1α increased left ventricular dP/dtmax.These results suggest that in rat neonatal cardiomyocytes, the SDF-1α/CXCR4 signaling increases calcium transients in an IP3-gated fashion leading to a positive chronotropic and inotropic effect.

  17. Analysis of ependymal ciliary beat pattern and beat frequency using high speed imaging: comparison with the photomultiplier and photodiode methods

    Directory of Open Access Journals (Sweden)

    O'Callaghan Chris

    2012-06-01

    Full Text Available Abstract Background The aim of this study was to compare beat frequency measurements of ependymal cilia made by digital high speed imaging to those obtained using the photomultiplier and modified photodiode techniques. Using high speed video analysis the relationship of the power and recover strokes was also determined. Methods Ciliated strips of ependyma attached to slices from the brain of Wistar rats were incubated at 30°C and observed using a ×50 water immersion lens. Ciliary beat frequency was measured using each of the three techniques: the high speed video, photodiode and photomultiplier. Readings were repeated after 30 minutes incubation at 37°C. Ependymal cilia were observed in slow motion and the precise movement of cilia during the recovery stroke relative to the path travelled during the power stroke was measured. Results The mean (95% confidence intervals beat frequencies determined by the high speed video, photomultiplier and photodiode at 30°C were 27.7 (26.6 to 28.8, 25.5 (24.4 to 26.6 and 20.8 (20.4 to 21.3 Hz, respectively. The mean (95% confidence intervals beat frequencies determined by the high speed video, photomultiplier and photodiode at 37°C were 36.4 (34 to 39.5, 38.4 (36.8 to 39.9 and 18.8 (16.9 to 20.5 Hz. The inter and intra observer reliability for measurement of ciliary beat frequency was 3.8% and 1%, respectively. Ependymal cilia were observed to move in a planar fashion during the power and recovery strokes with a maximum deviation to the right of the midline of 12.1(11.8 to 13.0° during the power stroke and 12.6(11.6 to 13.6° to the left of the midline during the recovery stroke. Conclusion The photodiode technique greatly underestimates ciliary beat frequency and should not be used to measure ependymal ciliary beat frequency at the temperatures studied. Ciliary beat frequency from the high speed video and photomultiplier techniques cannot be used interchangeably. Ependymal cilia had minimal deviation to

  18. Respiratory sinus arrhythmia during anaesthesia: assessment of respiration related beat-to-beat heart rate variability analysis methods.

    Science.gov (United States)

    Loula, P; Jäntti, V; Yli-Hankala, A

    1997-11-01

    Beat-to-beat heart rate variability analysis is a powerful tool for the diagnosis of neuropathy. Respiration-related heart rate variability (respiratory sinus arrhythmia, RSA) reflects the function of parasympathetic nervous system during spontaneous ventilation while awake. RSA is also claimed to monitor the depth of anaesthesia. Power spectrum analysis or various averaging techniques of the heart rate variability are usually applied. The current literature, however, does not usually interpret the ground rules and limitations of the method used, and this may sometimes lead to erroneous conclusions on the data. The aim of our study was to compare and analyse critically the performance of different methods of evaluating RSA during anaesthesia and positive pressure ventilation. Power spectrum analysis, the root mean square of the successive RR-interval difference (RMSSD), and two respiration related methods, RSA index and average phase RSA, were included in the comparison. To test these methods, 11 patients were anaesthetised with isoflurane and their lungs were ventilated mechanically with a frequency of 6 cycles min-1. Each patient received a bolus dose of atropine (20 micrograms kg-1) during the trial. Electrocardiogram, electroencephalogram and tracheal pressure signal from respirator were recorded and analyses were performed off-line. We demonstrated that general indices, such as RMSSD, may be strongly affected by heart rate level and other non-respiration related variations in heart rate. We also showed that the effect of unwanted fluctuations on RSA can be reduced with respiration dependent beat-to-beat methods. Furthermore we confirmed that in addition to the amplitude, also the pattern of respiratory sinus arrhythmia is of interest: the pattern is reversed in phase compared to spontaneous breathing while awake, as we have shown earlier. To analyse RSA during anaesthesia, we recommend the use of an average phase RSA method based on beat-to-beat variability

  19. Maternal assessment of pain in premature infants

    Directory of Open Access Journals (Sweden)

    Maria Carolina Correia dos Santos

    2015-12-01

    Full Text Available Objective: to identify mothers' perceptions about the pain in their premature babies in the Neonatal Intensive Care Unit. Methods: evaluative, quantitative study with investigative nature conducted with 19 mothers of hospitalized premature newborns. Data were obtained from closed questions, answered by mothers. Results: from the participants, two (10.5% reported that newborns are unable to feel pain. From the 17 mothers who said that premature babies can feel pain, the majority (94.1% identified crying as a characteristic of pain sensation. Eleven (64.7% stated that uneasiness is a sign of pain in newborns. Conclusion: for the proper management of neonatal pain it is essential that mothers know the signs of pain in premature newborns, and that health professionals instruct this recognition, through the enhancement of the maternal presence and practice of effective communication between professionals and newborns’ families.

  20. Future Applications of Antioxidants in Premature Infants

    Science.gov (United States)

    Lee, Jennifer W.; Davis, Jonathan M.

    2012-01-01

    Purpose of Review This review will examine the unique susceptibility of premature infants to oxidative stress, the role of reactive oxygen species (ROS) in the pathogenesis of common disorders of the preterm infant, and potential for therapeutic interventions using enzymatic and/or non-enzymatic antioxidants. Recent Findings Oxidative stress is caused by an imbalance between the production of ROS and the ability to detoxify them with the help of antioxidants. The premature infant is especially susceptible to ROS-induced damage because of inadequate antioxidant stores at birth, as well as impaired upregulation in response to oxidant stress. Thus, the premature infant is at increased risk for the development of ROS-induced diseases of the newborn, such as bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, and periventricular leukomalacia. Summary Potential therapies for ROS-induced disease include both enzymatic and non-enzymatic antioxidant preparations. More research is required to determine the beneficial effects of supplemental antioxidant therapy. PMID:21150443

  1. Apnea of prematurity: challenges and solutions

    Directory of Open Access Journals (Sweden)

    Picone S

    2014-06-01

    Full Text Available Simonetta Picone, Roberto Aufieri, Piermichele PaolilloDivision of Neonatology and Neonatal Intensive Care, Department of Maternal and Child Health, Casilino General Hospital, Rome, ItalyAbstract: Apnea of prematurity is a developmental disorder that frequently affects preterm infants, especially those with lower gestational age. Even if apnea of prematurity is by definition a self-limiting condition, it can cause serious problems during the hospital stay and can potentially have long-term neurological and cognitive consequences depending on the severity and intensity of the episodes. The diagnosis of apnea of prematurity can be made only after excluding a number of diseases of the preterm infant in which apnea may be an epiphenomenon. Etiological diagnosis is essential for selection of appropriate treatment, which may be nonpharmacological or involve use of drugs.Keywords: apnea of prematurity, idiopathic and secondary apnea, caffeine

  2. Premature dental eruption: report of case.

    LENUS (Irish Health Repository)

    McNamara, C M

    2011-08-05

    This case report reviews the variability of dental eruption and the possible sequelae. Dental eruption of the permanent teeth in cleft palate children may be variable, with delayed eruption the most common phenomenon. A case of premature dental eruption of a maxillary left first premolar is demonstrated, however, in a five-year-old male. This localized premature dental eruption anomaly was attributed to early extraction of the primary dentition, due to caries.

  3. Neuro-ophthalmic manifestations of prematurity

    OpenAIRE

    Preeti Patil Chhablani; Ramesh Kekunnaya

    2014-01-01

    Increasing rates of preterm births coupled with better survival of these infants have resulted in higher prevalence of systemic and ocular complications associated with prematurity. In addition to retinopathy of prematurity, infants who are born preterm may suffer from severe visual impairment as a result of hypoxic ischemic encephalopathy, hypoglycemia, and other metabolic imbalances. The effect of these processes on the anterior visual pathway may result in optic atrophy, optic nerve hypopl...

  4. PECULIARITIES OF BREAST FEEDING OF PREMATURE CHILDREN

    Directory of Open Access Journals (Sweden)

    V.К. Kotlukov

    2011-01-01

    Full Text Available The article presents main strategies of breast feeding of prematurely born infants support, such as use of Philips AVENT breast pumpfor lactation formation and feeding of the infant with native breast milk.Key words: premature infants, nursing mother, breast feeding support, modern accessories for breast feeding support. (Voprosy sovremennoi pediatrii — Current Pediatrics. 2011; 10 (6: 170–175

  5. The pathophysiology of acquired premature ejaculation

    OpenAIRE

    McMahon, Chris G; Jannini, Emmanuele A.; Serefoglu, Ege C.; Hellstrom, Wayne J.G.

    2016-01-01

    The second Ad Hoc International Society for Sexual Medicine (ISSM) Committee for the Definition of Premature Ejaculation defined acquired premature ejaculation (PE) as a male sexual dysfunction characterized by a the development of a clinically significant and bothersome reduction in ejaculation latency time in men with previous normal ejaculatory experiences, often to about 3 minutes or less, the inability to delay ejaculation on all or nearly all vaginal penetrations, and the presence of ne...

  6. Right ventricular metastasis of leiomyosarcoma

    Directory of Open Access Journals (Sweden)

    Stagmo Martin

    2009-05-01

    Full Text Available Abstract Metastatic presentation of leiomyosarcoma in the heart is very rare. We present transthoracic echocardiography and combined PET/CT images of a case with a large right ventricular metastasis of leiomyosarcoma. The patient was placed on cytostatic drugs for palliative purposes, but passed away one month later because of an untreatable ventricular tackycardia.

  7. Mitochondria and left ventricular hypertrophy

    Institute of Scientific and Technical Information of China (English)

    Haiyan Zhu; Shiwen Wang

    2008-01-01

    @@ Introduction Left ventricular hypertrophy (LVH) is one of the vicious organ damages of essential hypertension.It contributes a lot to high mortality of essential hypertension due to sudden cardiac death,ventricular arrhythmia and heart failure.Many factors involve in the pathogenesis of hypertension-induced LVH including inherited variants as well as environmental factors.

  8. Divertículo ventricular congênito associado à taquicardia ventricular Congenital ventricular diverticulum associated with ventricular tachycardia

    Directory of Open Access Journals (Sweden)

    Ranieli Pitol

    2005-02-01

    Full Text Available Divertículos ventriculares congênitos são raros. Clinicamente, podem ser assintomáticos ou causa de embolização sistêmica, insuficiência cardíaca, insuficiência valvar, ruptura ventricular, arritmia ventricular ou morte súbita. Apresentamos caso de uma mulher de 56 anos com taquicardia ventricular sustentada, na qual, durante a investigação, foi diagnosticada a presença de um divertículo na posição ínfero-basal do ventrículo esquerdo. Comentam-se as características clínicas e o tratamento desta doença infreqüente.Congenital ventricular diverticula are rare. Clinically, they may be asymptomatic or cause systemic embolization, heart failure, valvular regurgitation, ventricular rupture, ventricular arrhythmia, or sudden death. We report the case of a 56-year-old woman with sustained ventricular tachycardia, who, during investigation, was diagnosed with a diverticulum in the inferobasal portion of the left ventricle. The clinical characteristics and treatment of this rare disease are discussed.

  9. Efficiency of brainwave entrainment by binaural beats in reducing anxiety

    Directory of Open Access Journals (Sweden)

    Ahmad Alipoor

    2014-04-01

    Full Text Available Background: Anxiety is a fundamental phenomenon that is a common symptom in all mental disorders. The aim of the present study was to assess the effect of brainwave entrainment on anxiety reduction using binaural beats. Methods: In this experimental double-blind study, 30 employees were selected from an engineering research firm through random sampling and replacement and divided into two groups: control group and experimental group. All participants completed the Spielberger’s State-Trait Anxiety Inventory (STAI. Then, the experimental group listened to binaural beats which was recorded on a non-vocal piece of music for 4 weeks, 3 sessions each week. Each session lasted about 20 minutes. At the same time, the control group listened to the background music without any entrainment sound. At the end, both groups completed the anxiety questionnaire and the anxiety scores of both groups obtained before and after intervention were analyzed by ANCOVA. Results: The findings showed that the brainwave entrainment using binaural beats led to the significant reduction of state anxiety (P<0.001 and trait anxiety (P<0.018. Conclusion: Brainwave entrainment using binaural beats is an effective factor in decreasing state and trait anxiety; so, it can be used to reduce anxiety in mental health centers.

  10. Investigation on laser accelerators. Plasma beat wave accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Miura, Akihiko; Miyamoto, Yasuaki; Hagiwara, Masayoshi; Suzuki, Mitsutoshi; Sudo, Osamu [Power Reactor and Nuclear Fuel Development Corp., Tokai, Ibaraki (Japan). Tokai Works

    1998-04-01

    Laser accelerator technology has characteristics of high energy, compact, short pulse and high luminescence{center_dot}low emittance. This means potential many applications in wide ranges of fields as well as high energy and nuclear physics. High power short laser pulses are injected to a plasma in the typical example of laser accelerators. Large electric fields are induced in the plasma. Electrons in the plasma are accelerated with the ponderomotive force of the electric field. The principles of interaction on beat wave, wakefield accelerators, inverse free electron laser and inverse Cherenkov radiation are briefly introduced. The overview of plasma beat wave accelerator study is briefly described on the programs at Chalk River Laboratories(Canada), UCLA(USA), Osaka Univ. (Japan) and Ecole Polytechnique (France). Issues of the plasma beat wave accelerator are discussed from the viewpoint of application. Existing laser technologies of CO{sub 2}, YAG and YFL are available for the present day accelerator technology. An acceleration length of beat wave interaction is limited due to its phase condition. Ideas on multi-staged acceleration using the phasing plasma fiber are introduced. (Y. Tanaka)

  11. Using Science and Much More to Beat the Flood

    Science.gov (United States)

    Seeley, Claire

    2014-01-01

    The Beat the Flood challenge involves designing and building a model flood-proof home, which is then tested in "flood" conditions. It is set on the fictitious Watu Island. The children form teams, with each team member being assigned a responsibility for the duration of the task--team leader, chief recorder, and resource manager. This…

  12. Using Science and Much More to Beat the Flood

    Science.gov (United States)

    Seeley, Claire

    2014-01-01

    The Beat the Flood challenge involves designing and building a model flood-proof home, which is then tested in "flood" conditions. It is set on the fictitious Watu Island. The children form teams, with each team member being assigned a responsibility for the duration of the task--team leader, chief recorder, and resource manager. This…

  13. Reduced Order Dead-Beat Observers for a Bioreactor

    CERN Document Server

    Karafyllis, Iasson

    2010-01-01

    This paper studies the strong observability property and the reduced-order dead-beat observer design problem for a continuous bioreactor. New relationships between coexistence and strong observability, and checkable sufficient conditions for strong observability, are established for a chemostat with two competing microbial species. Furthermore, the dynamic output feedback stabilization problem is solved for the case of one species.

  14. Analysis of fluid flow around a beating artificial cilium

    Directory of Open Access Journals (Sweden)

    Mojca Vilfan

    2012-02-01

    Full Text Available Biological cilia are found on surfaces of some microorganisms and on surfaces of many eukaryotic cells where they interact with the surrounding fluid. The periodic beating of the cilia is asymmetric, resulting in directed swimming of unicellular organisms or in generation of a fluid flow above a ciliated surface in multicellular ones. Following the biological example, externally driven artificial cilia have recently been successfully implemented as micropumps and mixers. However, biomimetic systems are useful not only in microfluidic applications, but can also serve as model systems for the study of fundamental hydrodynamic phenomena in biological samples. To gain insight into the basic principles governing propulsion and fluid pumping on a micron level, we investigated hydrodynamics around one beating artificial cilium. The cilium was composed of superparamagnetic particles and driven along a tilted cone by a varying external magnetic field. Nonmagnetic tracer particles were used for monitoring the fluid flow generated by the cilium. The average flow velocity in the pumping direction was obtained as a function of different parameters, such as the rotation frequency, the asymmetry of the beat pattern, and the cilium length. We also calculated the velocity field around the beating cilium by using the analytical far-field expansion. The measured average flow velocity and the theoretical prediction show an excellent agreement.

  15. Frequency of neonatal complications after premature delivery

    Directory of Open Access Journals (Sweden)

    Gordana Grgić

    2013-04-01

    Full Text Available Introduction: Preterm delivery is the delivery before 37 weeks of gestation are completed. The incidence of preterm birth ranges from 5 to 15%. Aims of the study were to determine the average body weight, Apgar score after one and five minutes, and the frequency of the most common complications in preterminfants.Methods: The study involved a total of 631 newborns, of whom 331 were born prematurely Aims of this study were to (24th-37th gestational weeks-experimental group, while 300 infants were born in time (37-42 weeks of gestation-control group.Results: Average body weight of prematurely born infants was 2382 grams, while the average Apgar score in this group after the fi rst minute was 7.32 and 7.79 after the fifth minute. The incidence of respiratory distress syndrome was 50%, intracranial hemorrhage, 28.1% and 4.8% of sepsis. Respiratory distresssyndrome was more common in infants born before 32 weeks of gestation. Mortality of premature infants is present in 9.1% and is higher than that of infants born at term.Conclusions: Birth body weight and Apgar scores was lower in preterm infants. Respiratory distress syndrome is the most common fetal complication of prematurity. Intracranial hemorrhage is the second most common complication of prematurity. Mortality of premature infants is higher than the mortality of infants born at term birth.

  16. Circadian variations in the occurrence of ventricular tachyarrhythmias in patients with implantable cardioverter defibrillators.

    Science.gov (United States)

    Kozák, Milan; Krivan, Lubomír; Semrád, Borivoj

    2003-03-01

    A circadian distribution has been demonstrated in episodes of sudden cardiac death, acute myocardial infarction, ventricular premature complexes, heart rate variability, and ventricular tachyarrhythmias. The aim of this study was to evaluate the circadian distribution of ventricular tachyarrhythmia episodes in a population of ICD patients. Data were gathered from 72 patients (55 men, 17 women; mean age 62.7 +/- 12.2 years, mean LVEF 0.0037 +/- 0.0011) with ICDs implanted for standard indications. Patients were followed every 3 months over a mean period of 21 +/- 12.8 months. At each examination, symptoms at arrhythmia onset and perception of ICD therapy were recorded, and the ICD memory was interrogated. During follow-up, 1,023 episodes' of malignant ventricular arrhythmias were detected and effectively terminated, 506 of which were fully analyzed. A morning peak in ventricular tachyarrhythmias was demonstrated between 7:00 and 11:00 AM, and an afternoon peak between 6:00 and 7:00 PM. A significantly lower occurrence of VT was observed at 1:00 AM and between 4:00 and 6:00 AM. A circadian distribution in the occurrence of ventricular tachycardias was found. The three striking features of the data are: the early morning peak (about three hours after waking up), relatively stable incidence throughout waking hours, and decline in incidence in the previous period.

  17. EFFECT OF AROTINOLOL ON LEFT VENTRICULAR FUNCTION IN PATIENTS WITH IDIOPATHIC DILATED CARDIOMYOPATHY

    Institute of Scientific and Technical Information of China (English)

    Chao-mei Fan; Xiu-qing Du; Na-qiang Lu; Hong Yang; Yi-shi Li; Li Xu; Ke-fei DOU; Jing-lin Zhao; Xian-qi Yuan; Yan-fen Zhao; Rong-fang Shi

    2007-01-01

    To evaluate the efficacy and safety of long-term treatment with arotinolol in patients with idiopathic dilated cardiomyopathy (IDCM).Methods Sixty-three patients with IDCM were evaluated at baseline and after 12-month therapy with arotinolol.The conventional therapy for congestive heart failure was continued throughout the study with arotinolol as the only β-blocker. Left ventricular function was assessed with the New York Heart Association functional class and two-dimensional echocardiography.Results After 12-month arotinolol treatment, there was a significant improvement in left ventricular systolic function. Left ventricular end-systolic dimension significantly decreased from 59. 52 ± 8. 83 mm to 50. 89 ± 8.17 mm (P <0.001). Left ventricular ejection fraction significantly increased from 27.39% ±7.94% to 41.13% ±9.45% (P <0.001). Left ventricular mass index decreased from 150. 47 ± 42. 42 g/m2 to 141.58 ± 34.36 g/m2 ( P<0.01). No adverse events leading to premature discontinuation of study drug occurred.Conclusion In this preliminary study, 12-month arotinolol treatment has a favorable effect on left ventricular function in patients with IDCM, and it is safe and well tolerated.

  18. Teflon-buttressed sutures plus pericardium patch repair left ventricular rupture caused by radiofrequency catheter ablation: A case report.

    Science.gov (United States)

    Cao, Hao; Zhang, Qi; He, Yanzhong; Feng, Xiaodong; Liu, Zhongmin

    2016-09-01

    Cardiac rupture often occurs after myocardial infarction or chest trauma with a high mortality rate. However, left ventricular rupture caused by radiofrequency catheter ablation (RFCA) is extremely rare. We describe a case of a 61-year-old male who survived from left ventricular rupture caused by a RFCA procedure for frequent ventricular premature contractions. Surgical exploration with cardiopulmonary bypass (CPB) was performed when the signs of cardiac tamponade developed 7 hours after the ablation surgery. Teflon-buttressed sutures of the tear in the left ventricular posterolateral wall and pericardium patch applied to the contusion region on the wall repaired the rupture safely and effectively. Timely surgical intervention under CPB facilitated the survival of the patient. Teflon-buttressed sutures plus pericardium patch achieved the successful repair of the rupture.

  19. Ambulatory instrument for monitoring indirect beat-to-beat blood pressure in superficial temporal artery using volume-compensation method.

    Science.gov (United States)

    Tanaka, S; Yamakoshi, K

    1996-11-01

    A portable instrument, based on a volume-compensation technique, is designed for ambulatory monitoring of indirect beat-to-beat blood pressure (BP) in the superficial temporal artery. The instrument consists of a small disc-type cuff and a portable unit carried by the subject. Several components are integrated in the cuff for applying counter-pressure to the artery, i.e. a reflectance-type photo-plethysmographic sensor for arterial volume detection, a pressure sensor for cuff pressure Pc measurement and a nozzle flapper-type- electro-pneumatic convertor for controlling Pc. The portable unit includes volume servo control circuitry and a microprocessor-based signal-processing and recording unit. This automatically performs all the necessary measurement procedures and stores into a memory IC element the processed systolic, mean and diastolic blood pressure data, together with pulse intervals on a beat-to-beat basis from the servo-controlled Pc (indirectly measured BP waveform). With this instrument, momentary changes in BP during ambulatory situations such as bicycle ergometer exercise and daily activities including motorway driving are successfully recorded. From the results of simultaneous measurement of the subject's posture changes, the effect of posture change on blood pressure, e.g. baroreceptor-cardiac reflex, is also clearly demonstrated.

  20. The Beats as Cultural Others/Exotics in Recent Memoirs by Exile Poets

    DEFF Research Database (Denmark)

    Sørensen, Bent

    with figures associated with the Beat Generation. This paper examines the representation of Beat writers such as Ginsberg and Jack Kerouac in Codrescu and Simic's texts, and argues that the exile poets overlay the well-known figures of the Beat writers with yet another dimension of otherness and exoticism...

  1. Symbolic dynamics of ventricular tachycardia and ventricular fibrillation

    Science.gov (United States)

    Wang, Jun; Chen, Jie

    2010-05-01

    In this paper, the symbolic dynamics analysis was used to analyze the complexity of normal heartbeat signal (NSR), Ventricular tachycardia (VT) and ventricular fibrillation (VF) signals. By calculating the information entropy value of symbolic sequences, the complexities were quantified. Based on different information entropy values, NSR, VT and VF signals were distinguished with satisfactory results. The study showed that a sudden drop of symbolic sequence’s entropy value indicated that the patients most likely entered the episode of ventricular tachycardia and this was a crucial episode for the clinical treatment of patients. It had important clinical significance for the automatic diagnosis.

  2. Dynamic control of maximal ventricular elastance via the baroreflex and force-frequency relation in awake dogs before and after pacing-induced heart failure

    Science.gov (United States)

    Chen, Xiaoxiao; Sala-Mercado, Javier A.; Hammond, Robert L.; Ichinose, Masashi; Soltani, Soroor; Mukkamala, Ramakrishna

    2010-01-01

    We investigated to what extent maximal ventricular elastance (Emax) is dynamically controlled by the arterial baroreflex and force-frequency relation in conscious dogs and to what extent these mechanisms are attenuated after the induction of heart failure (HF). We mathematically analyzed spontaneous beat-to-beat hemodynamic variability. First, we estimated Emax for each beat during a baseline period using the ventricular unstressed volume determined with the traditional multiple beat method during vena cava occlusion. We then jointly identified the transfer functions (system gain value and time delay per frequency) relating beat-to-beat fluctuations in arterial blood pressure (ABP) to Emax (ABP→Emax) and beat-to-beat fluctuations in heart rate (HR) to Emax (HR→Emax) to characterize the dynamic properties of the arterial baroreflex and force-frequency relation, respectively. During the control condition, the ABP→Emax transfer function revealed that ABP perturbations caused opposite direction Emax changes with a gain value of −0.023 ± 0.012 ml−1, whereas the HR→Emax transfer function indicated that HR alterations caused same direction Emax changes with a gain value of 0.013 ± 0.005 mmHg·ml−1·(beats/min)−1. Both transfer functions behaved as low-pass filters. However, the ABP→Emax transfer function was more sluggish than the HR→Emax transfer function with overall time constants (indicator of full system response time to a sudden input change) of 11.2 ± 2.8 and 1.7 ± 0.5 s (P < 0.05), respectively. During the HF condition, the ABP→Emax and HR→Emax transfer functions were markedly depressed with gain values reduced to −0.0002 ± 0.007 ml−1 and −0.001 ± 0.004 mmHg·ml−1·(beats/min)−1 (P < 0.1). Emax is rapidly and significantly controlled at rest, but this modulation is virtually abolished in HF. PMID:20435845

  3. Systolic left ventricular function according to left ventricular concentricity and dilatation in hypertensive patients

    DEFF Research Database (Denmark)

    Bang, Casper; Gerdts, Eva; Aurigemma, Gerard P;

    2013-01-01

    Left ventricular hypertrophy [LVH, high left ventricular mass (LVM)] is traditionally classified as concentric or eccentric based on left ventricular relative wall thickness. We evaluated left ventricular systolic function in a new four-group LVH classification based on left ventricular dilatatio...

  4. Premature Ejaculation and Utilization of Cognitive Techniques

    Directory of Open Access Journals (Sweden)

    Serkan AKKOYUNLU

    2013-03-01

    Full Text Available Introduction: Premature ejaculation is the most common male sexual dysfunction leading to distress in many couples. Master and Johnson emphasized the concept of early learned experiences and Kaplan emphasized lack of sensory awareness. For treatment sex therapists mainly utilize start-stop and squeeze techniques as homework. Couples enter sex therapy with some cognitive distortions and beliefs about sex and sexuality. These beliefs are also named sexual myths. For some couples using techniques to challenge cognitive distortions and maladaptive beliefs about sex and sexuality can be used. In this paper by presenting a case we discussed how cognitive techniques can be used along with behaviour techniques with couples. Case: Presenting clients are five years married couple who are thirty and twenty nine years old respectively. They attended to the outpatient clinic with the request of the female client. Their main complaint was premature ejaculation. They were diagnosed premature ejaculation using clinical interview. In treatment besides start and stop technique, cognitive techniques were utilized to address dysfunctional beliefs about sexuality. Discussion: Premature ejaculation is a male sexual dysfunction that causes distress and intimacy problems between couples. Stop start and squeeze techniques were accepted as the choice of treatment but their effectiveness is questioned recently. Also cognitive distortions and maladaptive beliefs may hamper therapy progress. Besides that, behavioral techniques utilizing cognitive techniques to lessen the degree of dysfunctional beliefs about sex and sexuality may help the couple to overcome premature ejaculation and enhance sexual satisfaction and intimacy.

  5. Observational cohort study of ventricular arrhythmia in adults with Marfan syndrome caused by FBN1 mutations.

    Directory of Open Access Journals (Sweden)

    Ali Aydin

    Full Text Available BACKGROUND: Marfan syndrome is associated with ventricular arrhythmia but risk factors including FBN1 mutation characteristics require elucidation. METHODS AND RESULTS: We performed an observational cohort study of 80 consecutive adults (30 men, 50 women aged 42±15 years with Marfan syndrome caused by FBN1 mutations. We assessed ventricular arrhythmia on baseline ambulatory electrocardiography as >10 premature ventricular complexes per hour (>10 PVC/h, as ventricular couplets (Couplet, or as non-sustained ventricular tachycardia (nsVT, and during 31±18 months of follow-up as ventricular tachycardia (VT events (VTE such as sudden cardiac death (SCD, and sustained ventricular tachycardia (sVT. We identified >10 PVC/h in 28 (35%, Couplet/nsVT in 32 (40%, and VTE in 6 patients (8%, including 3 with SCD (4%. PVC>10/h, Couplet/nsVT, and VTE exhibited increased N-terminal pro-brain natriuretic peptide serum levels(P10/h and Couplet/nsVT also related to increased indexed end-systolic LV diameters (P = .024 and P = .020, to moderate mitral valve regurgitation (P = .018 and P = .003, and to prolonged QTc intervals (P = .001 and P = .006, respectively. Moreover, VTE related to mutations in exons 24-32 (P = .021. Kaplan-Meier analysis corroborated an association of VTE with increased NT-proBNP (P<.001 and with mutations in exons 24-32 (P<.001. CONCLUSIONS: Marfan syndrome with causative FBN1 mutations is associated with an increased risk for arrhythmia, and affected persons may require life-long monitoring. Ventricular arrhythmia on electrocardiography, signs of myocardial dysfunction and mutations in exons 24-32 may be risk factors of VTE.

  6. Effect of Loss of Heart Rate Variability on T-Wave Heterogeneity and QT Variability in Heart Failure Patients: Implications in Ventricular Arrhythmogenesis.

    Science.gov (United States)

    Nayyar, Sachin; Hasan, Muhammad A; Roberts-Thomson, Kurt C; Sullivan, Thomas; Baumert, Mathias

    2017-03-03

    Heart rate variability (HRV) modulates dynamics of ventricular repolarization. A diminishing value of HRV is associated with increased vulnerability to life-threatening ventricular arrhythmias, however the causal relationship is not well-defined. We evaluated if fixed-rate atrial pacing that abolishes the effect of physiological HRV, will alter ventricular repolarization wavefronts and is relevant to ventricular arrhythmogenesis. The study was performed in 16 subjects: 8 heart failure patients with spontaneous ventricular tachycardia [HFVT], and 8 subjects with structurally normal hearts (H Norm). The T-wave heterogeneity descriptors [total cosine angle between QRS and T-wave loop vectors (TCRT, negative value corresponds to large difference in the 2 loops), T-wave morphology dispersion, T-wave loop dispersion] and QT intervals were analyzed in a beat-to-beat manner on 3-min records of 12-lead surface ECG at baseline and during atrial pacing at 80 and 100 bpm. The global T-wave heterogeneity was expressed as mean values of each of the T-wave morphology descriptors and variability in QT intervals (QTV) as standard deviation of QT intervals. Baseline T-wave morphology dispersion and QTV were higher in HFVT compared to H Norm subjects (p ≤ 0.02). While group differences in T-wave morphology dispersion and T-wave loop dispersion remained unaltered with atrial pacing, TCRT tended to fall more in HFVT patients compared to H Norm subjects (interaction p value = 0.086). Atrial pacing failed to reduce QTV in both groups, however group differences were augmented (p < 0.0001). Atrial pacing and consequent loss of HRV appears to introduce unfavorable changes in ventricular repolarization in HFVT subjects. It widens the spatial relationship between wavefronts of ventricular depolarization and repolarization. This may partly explain the concerning relation between poorer HRV and the risk of ventricular arrhythmias.

  7. Recovery of spray paint traces from clothing by beating.

    Science.gov (United States)

    Olderiks, Maurice; Baiker, Martin; van Velzen, Jill; van der Weerd, Jaap

    2015-03-01

    Manual recovery of spray paints from textiles using a microscope, the routine method in many laboratories, is often laborious. Beating the clothing with a plastic rod, the routine method used for recovery of glass traces within the authors' laboratory, is proposed as an alternative. The efficiency of the method was evaluated by spray tests with fluorescent paint. In these tests, paint particles in the acquired debris samples, as well as those remaining on the textiles, were investigated. The results show that beating is an efficient way to recover and concentrate paint particles. A good efficiency for jeans fabric and rough knitwear is reported. The results appeared to be less satisfactory for smooth woven fabric. Application of the method in casework was effective for graffiti paints as well as for flaked car paint. © 2014 American Academy of Forensic Sciences.

  8. Finding the ciliary beating pattern with optimal efficiency

    CERN Document Server

    Osterman, Natan

    2011-01-01

    We introduce a measure for energetic efficiency of biological cilia acting individually or collectively and numerically determine the optimal beating patterns according to this criterion. Maximizing the efficiency of a single cilium leads to curly, often symmetric and somewhat counterintuitive patterns. But when looking at a densely ciliated surface, the optimal patterns become remarkably similar to what is observed in microorganisms like Paramecium. The optimal beating pattern then consists of a fast effective stroke and a slow sweeping recovery stroke. Metachronal coordination is essential for efficient pumping and the highest efficiency is achieved with antiplectic waves. Efficiency also increases with an increasing density of cilia up to the point where crowding becomes a problem. We finally relate the pumping efficiency of cilia to the swimming efficiency of a spherical microorganism and show that the experimentally estimated efficiency of Paramecium is surprisingly close to the theoretically possible op...

  9. First Beta-Beating Measurement in the LHC

    CERN Document Server

    Aiba, M; Franchi, A; Giovannozzi, M; Kain, V; Morita, A; Tomás, R; Vanbavinckhove, G; Wenninger, J

    2009-01-01

    This note reports on the first LHC beta-beating and coupling measurements. Thanks to an excellent functioning of the BPM system and the related software, injection oscillations were recorded for the first 90 turns at all BPMs of Beam 2. Three different algorithms are used to measure the optics parameters from the BPM data. All algorithms show consistent measurements but feature different accuracy. The Singular Value Decomposition (SVD) approach shows a high resolution despite the limited number of turns. The vertical beta-beating is observed to be about a factor of two larger than in the horizontal plane. This asymetry is partly due to sextupoles misalignments but also suggests the possible existance of focusing errors at defocussing locations. Rather large coupling is observed since no skew quadrupole was excited at the time of the data acquisition. We also report a list of suspected malfunctioning BPMs identified through various analyses.

  10. The Effect of Binaural Beats on Visuospatial Working Memory and Cortical Connectivity.

    Science.gov (United States)

    Beauchene, Christine; Abaid, Nicole; Moran, Rosalyn; Diana, Rachel A; Leonessa, Alexander

    2016-01-01

    Binaural beats utilize a phenomenon that occurs within the cortex when two different frequencies are presented separately to each ear. This procedure produces a third phantom binaural beat, whose frequency is equal to the difference of the two presented tones and which can be manipulated for non-invasive brain stimulation. The effects of binaural beats on working memory, the system in control of temporary retention and online organization of thoughts for successful goal directed behavior, have not been well studied. Furthermore, no studies have evaluated the effects of binaural beats on brain connectivity during working memory tasks. In this study, we determined the effects of different acoustic stimulation conditions on participant response accuracy and cortical network topology, as measured by EEG recordings, during a visuospatial working memory task. Three acoustic stimulation control conditions and three binaural beat stimulation conditions were used: None, Pure Tone, Classical Music, 5Hz binaural beats, 10Hz binaural beats, and 15Hz binaural beats. We found that listening to 15Hz binaural beats during a visuospatial working memory task not only increased the response accuracy, but also modified the strengths of the cortical networks during the task. The three auditory control conditions and the 5Hz and 10Hz binaural beats all decreased accuracy. Based on graphical network analyses, the cortical activity during 15Hz binaural beats produced networks characteristic of high information transfer with consistent connection strengths throughout the visuospatial working memory task.

  11. The role of the basal ganglia in beat perception: neuroimaging and neuropsychological investigations.

    Science.gov (United States)

    Grahn, Jessica A

    2009-07-01

    Perception of musical rhythms is culturally universal. Despite this special status, relatively little is known about the neurobiology of rhythm perception, particularly with respect to beat processing. Findings are presented here from a series of studies that have specifically examined the neural basis of beat perception, using functional magnetic resonance imaging (fMRI) and studying patients with Parkinson's disease. fMRI data indicate that novel beat-based sequences robustly activate the basal ganglia when compared to irregular, nonbeat sequences. Furthermore, although most healthy participants find it much easier to discriminate changes in beat-based sequences compared to irregular sequences, Parkinson's disease patients fail to show the same degree of benefit. Taken together, these data suggest that the basal ganglia are performing a crucial function in beat processing. The results of an additional fMRI study indicate that the role of the basal ganglia is strongly linked to internal generation of the beat. Basal ganglia activity is greater when participants listen to rhythms in which internal generation of the beat is required, as opposed to rhythms with strongly externally cued beats. Functional connectivity between part of the basal ganglia (the putamen) and cortical motor areas (premotor and supplementary motor areas) is also higher during perception of beat rhythms compared to nonbeat rhythms. Increased connectivity between cortical motor and auditory areas is found in those with musical training. The findings from these converging methods strongly implicate the basal ganglia in processing a regular beat, particularly when internal generation of the beat is required.

  12. WITHDRAWN: Successful bipolar catheter ablation of ventricular premature complex from the posterior papillary muscle.

    Science.gov (United States)

    Kitamura, Takeshi; Fukamizu, Seiji; Sakurada, Harumizu; Hiraoka, Masayasu

    2014-01-28

    This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

  13. Measuring of beat up force on weaving machines

    Directory of Open Access Journals (Sweden)

    Bílek Martin

    2017-01-01

    Full Text Available The textile material (warp is stressed cyclically at a relative high frequency during the weaving process. Therefore, the special measuring device for analysis of beat up force in the textile material during the weaving process, has been devised in the Weaving Laboratory of the TUL. This paper includes a description of this measuring device. The experimental part includes measurements results for various materials (PES and VS and various warp thread densities of the produced fabric.

  14. Visualization of calcium transients controlling orientation of ciliary beat.

    Science.gov (United States)

    Tamm, S L; Terasaki, M

    1994-06-01

    To image changes in intraciliary Ca controlling ciliary motility, we microinjected Ca Green dextran, a visible wavelength fluorescent Ca indicator, into eggs or two cell stages of the ctenophore Mnemiopsis leidyi. The embryos developed normally into free-swimming, approximately 0.5 mm cydippid larvae with cells and ciliary comb plates (approximately 100 microns long) loaded with the dye. Comb plates of larvae, like those of adult ctenophores, undergo spontaneous or electrically stimulated reversal of beat direction, triggered by Ca influx through voltage-sensitive Ca channels. Comb plates of larvae loaded with Ca Green dextran emit spontaneous or electrically stimulated fluorescent flashes along the entire length of their cilia, correlated with ciliary reversal. Fluorescence intensity peaks rapidly (34-50 ms), then slowly falls to resting level in approximately 1 s. Electrically stimulated Ca Green emissions often increase in steps to a maximum value near the end of the stimulus pulse train, and slowly decline in 1-2 s. In both spontaneous and electrically stimulated flashes, measurements at multiple sites along a single comb plate show that Ca Green fluorescence rises within 17 ms (1 video field) and to a similar relative extent above resting level from base to tip of the cilia. The decline of fluorescence intensity also begins simultaneously and proceeds at similar rates along the ciliary length. Ca-free sea water reversibly abolishes spontaneous and electrically stimulated Ca Green ciliary emissions as well as reversed beating. Calculations of Ca diffusion from the ciliary base show that Ca must enter the comb plate along the entire length of the ciliary membranes. The voltage-dependent Ca channels mediating changes in beat direction are therefore distributed over the length of the comb plate cilia. The observed rapid and virtually instantaneous Ca signal throughout the intraciliary space may be necessary for reprogramming the pattern of dynein activity

  15. Passive and active ventricular elastances of the left ventricle

    Directory of Open Access Journals (Sweden)

    Ng Eddie YK

    2005-02-01

    Full Text Available Abstract Background Description of the heart as a pump has been dominated by models based on elastance and compliance. Here, we are presenting a somewhat new concept of time-varying passive and active elastance. The mathematical basis of time-varying elastance of the ventricle is presented. We have defined elastance in terms of the relationship between ventricular pressure and volume, as: dP = EdV + VdE, where E includes passive (Ep and active (Ea elastance. By incorporating this concept in left ventricular (LV models to simulate filling and systolic phases, we have obtained the time-varying expression for Ea and the LV-volume dependent expression for Ep. Methods and Results Using the patient's catheterization-ventriculogram data, the values of passive and active elastance are computed. Ea is expressed as: ; Epis represented as: . Ea is deemed to represent a measure of LV contractility. Hence, Peak dP/dt and ejection fraction (EF are computed from the monitored data and used as the traditional measures of LV contractility. When our computed peak active elastance (Ea,max is compared against these traditional indices by linear regression, a high degree of correlation is obtained. As regards Ep, it constitutes a volume-dependent stiffness property of the LV, and is deemed to represent resistance-to-filling. Conclusions Passive and active ventricular elastance formulae can be evaluated from a single-beat P-V data by means of a simple-to-apply LV model. The active elastance (Ea can be used to characterize the ventricle's contractile state, while passive elastance (Ep can represent a measure of resistance-to-filling.

  16. Serum fructosamine and retinopathy of prematurity.

    Science.gov (United States)

    Bozdag, Senol; Oguz, Serife Suna; Gokmen, Tulin; Tunay, Zuhal; Tok, Levent; Uras, Nurdan; Erdeve, Omer; Dilmen, Ugur

    2011-12-01

    To determine whether serum fructosamine which is a good marker for detecting hyperglycemia during the previous 2 to 3 wk in infants could predict the development of retinopathy of prematurity in very low birth weight infants. One hundred sixty seven premature infants who had a birth weight of < 1500 g and a gestational age of less than 32 wk were investigated in the present study. Blood glucose was measured at the bedside and infants were recorded as hyperglycemic if their mean blood glucose levels were higher than 150 mg/dL. Serum corrected fructosamine level was obtained from the cord blood at birth and after the first month of life. The infants' eyes were examined by ophthalmologists to detect retinopathy of prematurity at the gestational age of 32 wk or at four wk after birth, whichever came first. Corrected fructosamine was 319.6 ± 59.6 and 272.8 ± 50.6 mmol/l for group 1 on 1(st) and 30(th) day respectively; 320 ± 61.7 and 268.2 ± 47.3 mmol/l for groups 2 + 3 on 1(st) and 30(th) day respectively which did not differ between groups (p = 0.766 and p = 0.665), whereas duration of hyperglycemia was 1.69 ± 1.1 day in group 1 compared with 3.05 ± 2.4 day in groups 2 + 3 which was significantly different (p = 0.019). The multivariate regression analysis indicated that the duration of hyperglycemia in days was significantly correlated with the development of retinopathy of prematurity (OR 3.26; 95% CI 1.09-9.80; p = 0.035). Although the duration of hyperglycemia may contribute to the development of retinopathy of prematurity, serum corrected fructosamine does not have a good predictive value in developing retinopathy of prematurity in very-low-birth-weight (VLBW) infants.

  17. Effectiveness of binaural beats in reducing preoperative dental anxiety.

    Science.gov (United States)

    Isik, B K; Esen, A; Büyükerkmen, B; Kilinç, A; Menziletoglu, D

    2017-07-01

    Binaural beats are an auditory illusion perceived when two different pure-tone sine waves are presented one to each ear at a steady intensity and frequency. We evaluated their effectiveness in reducing preoperative anxiety in dentistry. Sixty patients (30 in each group) who were to have impacted third molars removed were studied (experimental group: 20 women and 10 men, mean (range) age 24 (18-35) years, and control group: 22 women and 8 men, mean (range) age 28 (15-47) years). All patients were fully informed about the operation preoperatively, and their anxiety recorded on a visual analogue scale (VAS). The local anaesthetic was given and the patients waited for 10minutes, during which those in the experimental group were asked to listen to binaural beats through stereo earphones (200Hz for the left ear and 209.3Hz for the right ear). No special treatment was given to the control group. In both groups anxiety was then recorded again, and the tooth removed in the usual way. The paired t test and t test were used to assess the significance of differences between groups. The degree of anxiety in the control group was unchanged after the second measurement (p=0.625), while that in the experimental group showed a significant reduction in anxiety (p=0.001). We conclude that binaural beats may be useful in reducing preoperative anxiety in dentistry. Copyright © 2017 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  18. Moving to the beat and singing are linked in humans

    Directory of Open Access Journals (Sweden)

    Simone eDalla Bella

    2015-12-01

    Full Text Available The abilities to sing and to move to the beat of a rhythmic auditory stimulus emerge early during development, and both engage perceptual, motor, and sensorimotor processes. These similarities between singing and synchronization to a beat may be rooted in biology. Patel (2008 has suggested that motor synchronization to auditory rhythms may have emerged during evolution as a byproduct of selection for vocal learning (vocal learning and synchronization hypothesis. This view predicts a strong link between vocal performance and synchronization skills in humans. Here we tested this prediction by asking occasional singers to tap along with auditory pulse trains and to imitate familiar melodies. Both vocal imitation and synchronization skills were measured in terms of accuracy and precision or consistency. Accurate and precise singers tapped more in the vicinity of the pacing stimuli (i.e., they were more accurate than inaccurate and imprecise singers. Moreover, accurate singers were more consistent when tapping to the beat. These differences cannot be ascribed to basic motor skills or to motivational factors. Individual differences in terms of singing proficiency and synchronization skills may reflect the variability of a shared sensorimotor translation mechanism.

  19. Moving to the Beat and Singing are Linked in Humans

    Science.gov (United States)

    Dalla Bella, Simone; Berkowska, Magdalena; Sowiński, Jakub

    2015-01-01

    The abilities to sing and to move to the beat of a rhythmic auditory stimulus emerge early during development, and both engage perceptual, motor, and sensorimotor processes. These similarities between singing and synchronization to a beat may be rooted in biology. Patel (2008) has suggested that motor synchronization to auditory rhythms may have emerged during evolution as a byproduct of selection for vocal learning (“vocal learning and synchronization hypothesis”). This view predicts a strong link between vocal performance and synchronization skills in humans. Here, we tested this prediction by asking occasional singers to tap along with auditory pulse trains and to imitate familiar melodies. Both vocal imitation and synchronization skills were measured in terms of accuracy and precision or consistency. Accurate and precise singers tapped more in the vicinity of the pacing stimuli (i.e., they were more accurate) than less accurate and less precise singers. Moreover, accurate singers were more consistent when tapping to the beat. These differences cannot be ascribed to basic motor skills or to motivational factors. Individual differences in terms of singing proficiency and synchronization skills may reflect the variability of a shared sensorimotor translation mechanism. PMID:26733370

  20. Elastic Beating Pump Using Induced-Charge Electro-osmosis

    Science.gov (United States)

    Sugioka, Hideyuki

    2016-10-01

    Pumping a viscous liquid in a confined space is essential in microfluidic systems because the pressure-driven flow rate through small channels decreases with the third or fourth power of the channel size. Hence, inspired by a cilium's pumping ability in a confined space, we propose an elastic beating pump using a hydrodynamic force due to induced-charge electro-osmosis (ICEO) and numerically examine the pumping performance. By the multiphysics coupled simulation technique based on the boundary element method along with the thin double-layer approximation, we find that by selecting the optimum rigidity of the elastic beam, the ICEO elastic beating pump functions effectively at high frequencies with low applied voltages and shows a large average flow velocity with a remarkably large peak velocity that may be useful to flow a liquid with unexpectedly high viscosity. Furthermore, we propose a simple model that explains the characteristics of the time response behavior of the ICEO elastic beating pump tosome extent. By this analysis, we can considerably contribute to developments in studies on the artificial cilia having versatile functions.

  1. The circadian variation of premature atrial contractions

    DEFF Research Database (Denmark)

    Larsen, Bjørn Strøier; Kumarathurai, Preman; Nielsen, Olav W

    2016-01-01

    AIMS: The aim of the study was to assess a possible circadian variation of premature atrial contractions (PACs) in a community-based population and to determine if the daily variation could be used to assess a more vulnerable period of PACs in predicting later incidence of atrial fibrillation (AF...... variation in heart rate. After adjusting for relevant risk factors, the risk of AF was equal in all time intervals throughout the day. CONCLUSION: Premature atrial contractions showed a circadian variation in subjects with frequent PACs. No specific time interval of the day was more predictive of AF than...

  2. Ventricular arrhythmias in Chagas disease

    Directory of Open Access Journals (Sweden)

    Marco Paulo Tomaz Barbosa

    2015-02-01

    Full Text Available Sudden death is one of the most characteristic phenomena of Chagas disease, and approximately one-third of infected patients develop life-threatening heart disease, including malignant ventricular arrhythmias. Fibrotic lesions secondary to chronic cardiomyopathy produce arrhythmogenic substrates that lead to the appearance and maintenance of ventricular arrhythmias. The objective of this study is to discuss the main clinical and epidemiological aspects of ventricular arrhythmias in Chagas disease, the specific workups and treatments for these abnormalities, and the breakthroughs needed to determine a more effective approach to these arrhythmias. A literature review was performed via a search of the PubMed database from 1965 to May 31, 2014 for studies of patients with Chagas disease. Clinical management of patients with chronic Chagas disease begins with proper clinical stratification and the identification of individuals at a higher risk of sudden cardiac death. Once a patient develops malignant ventricular arrhythmia, the therapeutic approach aims to prevent the recurrence of arrhythmias and sudden cardiac death by the use of implantable cardioverter defibrillators, antiarrhythmic drugs, or both. In select cases, invasive ablation of the reentrant circuit causing tachycardia may be useful. Ventricular arrhythmias are important manifestations of Chagas cardiomyopathy. This review highlights the absence of high-quality evidence regarding the treatment of ventricular arrhythmias in Chagas disease. Recognizing high-risk patients who require specific therapies, especially invasive procedures such as the implantation of cardioverter defibrillators and ablative approaches, is a major challenge in clinical practice.

  3. Population-based beat-to-beat QT analysis from Holter recordings in the long QT syndrome.

    Science.gov (United States)

    Page, Alex; McNitt, Scott; Xia, Xiaojuan; Zareba, Wojciech; Couderc, Jean-Philippe

    2017-08-10

    The increasing dissemination of wearable ECG recorders (e.g. Holter, patches, and strap sensors) enables the acquisition of large amounts of data during long periods of time. However, the clinical value of these long-term continuous recordings is hindered by the lack of automatic tools to extract clinically relevant information (other than non-sinus and life-threatening rhythms) from such long-term data, particularly when targeting population-based research. In this work, we propose and test a new tool for analyzing beat-to-beat interval measurements and extracting features from Holter ECGs. Specifically, we assess the adaptation of the QT interval following sudden changes in heart rate in the primary long QT types (1 & 2). We find that in long QT syndrome type 2, certain QT adaptation patterns can indicate a higher risk for cardiac events. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Neural Entrainment to the Beat: The "Missing-Pulse" Phenomenon.

    Science.gov (United States)

    Tal, Idan; Large, Edward W; Rabinovitch, Eshed; Wei, Yi; Schroeder, Charles E; Poeppel, David; Zion Golumbic, Elana

    2017-06-28

    Most humans have a near-automatic inclination to tap, clap, or move to the beat of music. The capacity to extract a periodic beat from a complex musical segment is remarkable, as it requires abstraction from the temporal structure of the stimulus. It has been suggested that nonlinear interactions in neural networks result in cortical oscillations at the beat frequency, and that such entrained oscillations give rise to the percept of a beat or a pulse. Here we tested this neural resonance theory using MEG recordings as female and male individuals listened to 30 s sequences of complex syncopated drumbeats designed so that they contain no net energy at the pulse frequency when measured using linear analysis. We analyzed the spectrum of the neural activity while listening and compared it to the modulation spectrum of the stimuli. We found enhanced neural response in the auditory cortex at the pulse frequency. We also showed phase locking at the times of the missing pulse, even though the pulse was absent from the stimulus itself. Moreover, the strength of this pulse response correlated with individuals' speed in finding the pulse of these stimuli, as tested in a follow-up session. These findings demonstrate that neural activity at the pulse frequency in the auditory cortex is internally generated rather than stimulus-driven. The current results are both consistent with neural resonance theory and with models based on nonlinear response of the brain to rhythmic stimuli. The results thus help narrow the search for valid models of beat perception.SIGNIFICANCE STATEMENT Humans perceive music as having a regular pulse marking equally spaced points in time, within which musical notes are temporally organized. Neural resonance theory (NRT) provides a theoretical model explaining how an internal periodic representation of a pulse may emerge through nonlinear coupling between oscillating neural systems. After testing key falsifiable predictions of NRT using MEG recordings, we

  5. Highly efficient derivation of ventricular cardiomyocytes from induced pluripotent stem cells with a distinct epigenetic signature

    Institute of Scientific and Technical Information of China (English)

    Huansheng Xu; Ibrahim J Domian; Erding Hu; Robert Willette; John Lepore; Alexander Meissner; Zhong Wang; Kenneth R Chien; B Alexander Yi; Hao Wu; Christoph Bock; Hongcang Gu; Kathy O Lui; Joo-Hye C Park; Ying Shao; Alyssa K Riley

    2012-01-01

    Cardiomyocytes derived from pluripotent stem cells can be applied in drug testing,disease modeling and cellbased therapy.However,without procardiogenic growth factors,the efficiency of cardiomyogenesis from pluripotent stem cells is usually low and the resulting cardiomyocyte population is heterogeneous.Here,we demonstrate that induced pluripotent stem cells (iPSCs) can be derived from murine ventricular myocytes (VMs),and consistent with other reports of iPSCs derived from various somatic cell types,VM-derived iPSCs (ViPSCs) exhibit a markedly higher propensity to spontaneously differentiate into beating cardiomyocytes as compared to genetically matched embryonic stem cells (ESCs) or iPSCs derived from tail-tip fibroblasts.Strikingly,the majority of ViPSC-derived cardiomyocytes display a ventricular phenotype.The enhanced ventricular myogenesis in ViPSCs is mediated via increased numbers of cardiovascular progenitors at early stages of differentiation.In order to investigate the mechanism of enhanced ventricular myogenesis from ViPSCs,we performed global gene expression and DNA methylation analysis,which revealed a distinct epigenetic signature that may be involved in specifying the VM fate in pluripotent stem cells.

  6. Ventricular ectopy and QTc-interval prolongation associated with dronedarone therapy.

    Science.gov (United States)

    Gonzalez, Jaime E; Sauer, William H; Krantz, Mori J

    2013-10-01

    Amiodarone is an effective treatment for atrial and ventricular arrhythmias, but its use is limited by a toxic adverse-effect profile. Although dronedarone has been touted as an antiarrhythmic agent devoid of both solid organ toxicity and proarrhythmic properties, its potential for prolonging ventricular repolarization may augment triggered ectopy. We describe a 66-year-old man who began dronedarone 400 mg twice/day for new-onset paroxysmal atrial fibrillation; he had no left ventricular dysfunction or clinical heart failure. Three months after starting the drug, he complained of malaise, fatigue, and rare palpitations. Twenty four-hour Holter monitoring revealed increased premature ventricular complexes, and the rate-corrected QT (QTc) interval was prolonged (range 525-760 msec). Dronedarone was discontinued and the patient's symptoms gradually resolved over the next 3 weeks. Holter monitoring revealed a marked reduction in ventricular ectopy burden, and the QTc interval decreased to his baseline values. Even in the absence of documented symptomatic torsade de pointes, this case suggests that caution should be exercised when prescribing dronedarone and that serial QTc interval monitoring may be appropriate. In addition, clinicians should have a low threshold to perform Holter monitoring if symptoms develop during dronedarone therapy.

  7. Cardiomyopathy Due to Nonsustained Ventricular Tachycardia Originating from the Aortic Sinus Cusp

    Directory of Open Access Journals (Sweden)

    Hamidreza Bonakdar

    2013-03-01

    Full Text Available We report a case of idiopathic nonsustained ventricular tachycardia (VT originating from the aortic sinus cusp referred for presyncope and LV dysfunction and frequent premature ventricular complex with no response to 3 months anti-arrhythmic medication for heart failure and arrhythmia. She was then referred to us for frequent PVC's and runs of nonsustained VT. ECG recorded during the nonsustained VT showed a left bundle branch block pattern in the precordial leads and an inferior axis and early transition in precordial leads in V3-V4. QS morphology in lead V1 was noticed with notching on the downward deflection. Electrophysiologic study was conducted to map ventricular outflow tract as a classic method, although pace map failed to find any matched QRS with the spontaneous PVCs. The mapping of aortic cusps was also performed. The best potential was recorded in a region located at the commissure of left-right aortic cusps. A single radiofrequency energy was delivered which resulted in immediate elimination of PVCs. The patient was discharged the day after ablation without any PVC recorded on monitor. Left ventricular ejection fraction(LVEF improved to normal level two months later. There was no PVC detected at serial holter monitoring. It seems logical not to overlook even an isolated or nonsustained ventricular arrhythmia considering the available and effective treatments such as ablation rather than congestive heart failure(CHF therapy especially in a young patient.

  8. Rupture of Right Ventricular Free Wall Following Ventricular Septal Rupture in Takotsubo Cardiomyopathy with Right Ventricular Involvement.

    Science.gov (United States)

    Sung, June Min; Hong, Sung Jin; Chung, In Hyun; Lee, Hye Young; Lee, Jae Hoon; Kim, Hyun Jung; Byun, Young Sup; Kim, Byung Ok; Rhee, Kun Joo

    2017-01-01

    Most patients diagnosed with takotsubo cardiomyopathies are expected to almost completely recover, and their prognosis is excellent. However, complications can occur in the acute phase. We present a case of a woman with takotsubo cardiomyopathy with right ventricular involvement who developed a rupture of the right ventricular free wall following ventricular septal rupture, as a consequence of an acute increase in right ventricular afterload by left-to-right shunt. Our case report illustrates that takotsubo cardiomyopathy can be life threatening in the acute phase. Ventricular septal rupture in biventricular takotsubo cardiomyopathy may be a harbinger of cardiac tamponade by right ventricular rupture.

  9. Relation between QT dispersion, left ventricle systolic function and frequency of ventricular arrhythmias in coronary patients

    Directory of Open Access Journals (Sweden)

    Stoičkov Viktor

    2007-01-01

    Full Text Available Introduction QT dispersion (QTd is a measure of non-homogeneous repolarisation of the myocardium and is used as an indicator of arrhythmogenicity. Objective The aim of this study was to assess the relation between QT dispersion, left ventricle systolic function and frequency of ventricular arrhythmias in coronary patients. Method We studied 290 coronary patients, 72 with angina pectoris and 218 after myocardial infarction. Eighty-one coronary patients had frequent and complex ventricular arrhythmias (out of them 19 had ventricular tachycardia and 209 were without arrhythmias or with infrequent ventricular premature contractions (VPC≤10/h. In all patients, QT dispersion, exercise test, 24-hour Holter monitoring and echocardiographic examination were performed. Results Patients with frequent and complex ventricular arrhythmias had significantly higher values of QTd (71.8±25.5 vs 55.6±21.7 ms; p<0.001, corrected QT dispersion (QTdc: 81.3±31.5 vs. 60.3±26.1 ms; p<0.001, left ventricular end-diastolic diameter (LVEDd: 56.2±6.9 vs. 53.4±6.2 mm; p<0.001 and left ventricular end-systolic diameter (LVESd: 39.5±6.2 vs. 36.0±6.3 mm; p<0.001, and significantly lower values of left ventricular ejection fraction (LVEF: 47.7±13.9 vs. 55.9±11.6%; p<0.001 in comparison to those without arrhythmias or with infrequent VPC. Patients with VT had significantly higher values of QTd and QTdc in comparison to other patients with frequent and complex ventricular arrhythmias (83.8±17.1 vs. 69.4±26.2 ms; p<0.02 for QTd; 101.1±23.9:77.6±31.4 ms; p<0.005 for QTdc. There is a significant negative correlation of QTd and QTdc with LVEF, and a significant positive correlation of QTd and QTdc with inside dimensions of the left ventricle, in patients with frequent and complex ventricular arrhythmias. Conclusion The study demonstrated that patients with frequent and complex ventricular arrhythmias had significantly higher values of QTd and QTdc, as well as a higher

  10. AMH as Predictor of Premature Ovarian Insufficiency

    DEFF Research Database (Denmark)

    Lunding, Stine Aa; Aksglæde, Lise; Anderson, Richard A

    2015-01-01

    CONTEXT: The majority of Turner syndrome (TS) patients suffer from accelerated loss of primordial follicles. Low circulating levels of anti-Müllerian hormone (AMH) may predict the lack of spontaneous puberty in prepubertal girls and imminent premature ovarian insufficiency (POI) in TS women...

  11. Premature ovarian failure and ovarian autoimmunity

    NARCIS (Netherlands)

    J.A. Schoemaker (Joop); H.A. Drexhage (Hemmo); A. Hoek (Annemieke)

    1997-01-01

    textabstractPremature ovarian failure (POF) is defined as a syndrome characterized by menopause before the age of 40 yr. The patients suffer from anovulation and hypoestrogenism. Approximately 1% of women will experience menopause before the age of 40 yr. POF is a

  12. [Nontraumatic chylopericardium and chylothorax in premature neonates].

    Science.gov (United States)

    Avrel'kina, E A; Ignat'eva, E N; Fediarova, M A; Pliukhin, S V

    2014-01-01

    Deaths of extremely premature babies undiagnosed as having spontaneous chylopericardium (CP) and chylothorax (CT) are analyzed. The specific features of these death cases are the polyetiology of CP/CT and the similarity of their pathogenesis in the absence of specific clinical symptomatology.

  13. Liver Abscess: Increasing Occurrence in Premature Newborns

    Directory of Open Access Journals (Sweden)

    OKTAV BOSNALI

    2013-03-01

    Full Text Available Neonatal liver abscess is a very rare condition associated with high morbidity and mortality rates. There seems to be an increasing trend of this rare condition amongst the newborns admitted to neonatal intensive care units. We report a case of liver abscess in a premature newborn and briefly review the literature and discuss its management.

  14. Liver Abscess: Increasing Occurrence in Premature Newborns

    Science.gov (United States)

    Bosnalı, Oktav; Moralıoğlu, Serdar; Pektaş, Osman

    2013-01-01

    Neonatal liver abscess is a very rare condition associated with high morbidity and mortality rates. There seems to be an increasing trend of this rare condition amongst the newborns admitted to neonatal intensive care units. We report a case of liver abscess in a premature newborn and briefly review the literature and discuss its management. PMID:26023443

  15. Liver Abscess: Increasing Occurrence in Premature Newborns

    Directory of Open Access Journals (Sweden)

    Oktav Bosnalı

    2013-04-01

    Full Text Available Neonatal liver abscess is a very rare condition associated with high morbidity and mortality rates. There seems to be an increasing trend of this rare condition amongst the newborns admitted to neonatal intensive care units. We report a case of liver abscess in a premature newborn and briefly review the literature and discuss its management.

  16. Premature mortality in Japan due to ozone

    Science.gov (United States)

    Nawahda, Amin; Yamashita, Ken; Ohara, Toshimasa; Kurokawa, Junichi; Ohizumi, Tsuyoshi; Chen, Fang; Akimoto, Hajime

    2013-12-01

    In Japan, all 47 prefectures conduct routine air quality monitoring at 1145 stations throughout the country to assess environmental effects. This study aims to provide a better understanding of possible estimations of premature mortality in Japan caused by exposure to monitored and modeled concentrations of tropospheric ozone during the period from January to December, 2005. The spatial distribution and temporal variation of ozone concentrations were modeled using the Models-3 Community Multiscale Air Quality modeling system coupled with the Regional Emission Inventory in Asia (CMAQ/REAS). Premature mortality caused by exposure to ozone was calculated assuming a relative risk (RR) value of 1.003 [95% Confidence Interval (CI): 1.001-1.004] for concentrations above 35 ppb according to the SOMO35 index (annual Sum of daily maximum 8-h Ozone Means Over 35 ppb) recommended by WHO (2008). Based on CMAQ/REAS simulations, the estimated all-cause premature mortality in 2005 is about 13,000 (95% CI: 4320-17,300) cases. This value is 2.5 times greater than the estimated premature mortality based on monitored ozone concentrations, which is 5220 (95% CI: 1740-6960) cases.

  17. Optimal oxygen saturation in premature infants

    Directory of Open Access Journals (Sweden)

    Meayoung Chang

    2011-09-01

    Full Text Available There is a delicate balance between too little and too much supplemental oxygen exposure in premature infants. Since underuse and overuse of supplemental oxygen can harm premature infants, oxygen saturation levels must be monitored and kept at less than 95% to prevent reactive oxygen species-related diseases, such as retinopathy of prematurity and bronchopulmonary dysplasia. At the same time, desaturation below 80 to 85% must be avoided to prevent adverse consequences, such as cerebral palsy. It is still unclear what range of oxygen saturation is appropriate for premature infants; however, until the results of further studies are available, a reasonable target for pulse oxygen saturation (SpO2 is 90 to 93% with an intermittent review of the correlation between SpO2 and the partial pressure of arterial oxygen tension (PaO2. Because optimal oxygenation depends on individuals at the bedside making ongoing adjustments, each unit must define an optimal target range and set alarm limits according to their own equipment or conditions. All staff must be aware of these values and adjust the concentration of supplemental oxygen frequently.

  18. New Information About Premature Births (For Consumers)

    Centers for Disease Control (CDC) Podcasts

    2006-10-06

    A new study finds that prematurity is the most frequent cause of infant death in the United States. Learn more.  Created: 10/6/2006 by CDC Division of Reproductive Health.   Date Released: 10/6/2006.

  19. Human cytomegalovirus infections in premature infants by ...

    African Journals Online (AJOL)

    Owner

    clinical importance of CMV infection in premature infants by breast-feeding is still unclear. This mini- ... Transmission of CMV by natural routes relates ... infection from the fresh breast milk containing the virus. ... As a result of transmission during the course of delivery ... hepatitis was speculated to be caused by primary.

  20. Premature ovarian failure and ovarian autoimmunity

    NARCIS (Netherlands)

    J.A. Schoemaker (Joop); H.A. Drexhage (Hemmo); A. Hoek (Annemieke)

    1997-01-01

    textabstractPremature ovarian failure (POF) is defined as a syndrome characterized by menopause before the age of 40 yr. The patients suffer from anovulation and hypoestrogenism. Approximately 1% of women will experience menopause before the age of 40 yr. POF is a heter

  1. Premature ovarian failure and ovarian autoimmunity

    NARCIS (Netherlands)

    J.A. Schoemaker (Joop); H.A. Drexhage (Hemmo); A. Hoek (Annemieke)

    1997-01-01

    textabstractPremature ovarian failure (POF) is defined as a syndrome characterized by menopause before the age of 40 yr. The patients suffer from anovulation and hypoestrogenism. Approximately 1% of women will experience menopause before the age of 40 yr. POF is a heter

  2. Laterality in Prematurely-Born Children.

    Science.gov (United States)

    Segalwitz, Sidney J.; Chapman, Jacqueline S.

    The study examined the relationship between perinatal stress and decreased right handedness and decreased left cerebral dominance for speech with 215 children born prematurely, followed from birth, and tested at age 5. Results indicated that neither hand preference nor hand performance correlated with degree of perinatal stress and that eye…

  3. Clustering of ventricular arrhythmic complexes in heart rhythm

    Science.gov (United States)

    Sokolova, Anastasia; Bogachev, Mikhail I.; Bunde, Armin

    2011-02-01

    We study the statistics of intervals τ between ventricular premature complexes (VPCs) in 24-h electrocardiogram records obtained from PhysioNet data source. We find that the long-term memory inherent in the heartbeat intervals leads to power laws in the probability density function P(τ) between VPCs for τ>6 s. As a consequence, the probability W(t,Δt) that at least one VPC will occur within the next time interval Δt, if the last VPC occurred t time units intervals ago, decays by a power law of t. Based on these results, we suggest a method to obtain a priori information about the occurrence of the next VPC, and how to predict it. We think that usage of this a priori information could be useful for the improvement of the algorithms in healthcare monitoring devices with alarm facilities.

  4. RESEARCH ON REDUCING PREMATURITY RUPTURE OF MEMBRANE

    Directory of Open Access Journals (Sweden)

    Maria URSACHI (BOLOTA

    2016-12-01

    Full Text Available The membranes surrounding the amniotic cavity are composed from amnion and chorion, tightly adherent layers which are composed of several cell types, including epithelial cells, trophoblasts cells and mesenchyme cells, embedded in a collagenous matrix. They retain amniotic fluid, secret substances into the amniotic fluid, as well as to the uterus and protect the fetus against upward infections from urogenital tract. Normally, the membranes it breaks during labor. Premature rupture of the amniotic sac (PRAS is defined as rupture of membranes before the onset of labor. Premature rupture of the fetal membrane, which occurs before 37 weeks of gestation, usually, refers to preterm premature rupture of membranes. Despite advances in the care period, premature rupture of membranes and premature rupture of membranes preterm continue to be regarded as serious obstetric complications. On the term 8% - 10% of pregnant women have premature rupture of membranes; these women are at increased risk of intrauterine infections, where the interval between membrane rupture and expulsion is rolled-over. Premature rupture of membranes preterm occurs in approximately 1% of all pregnancies and is associated with 30% -40% of preterm births. Thus, it is important to identify the cause of pre-term birth (after less than 37 completed weeks of "gestation" and its complications, including respiratory distress syndrome, neonatal infection and intraventricular hemorrhage. Objectives: the development of the protocol of the clinical trial on patients with impending preterm birth, study clinical and statistical on the socio-demographic characteristics of patients with imminent preterm birth; clinical condition of patients and selection of cases that could benefit from the application of interventional therapy; preclinical investigation (biological and imaging of patients with imminent preterm birth; the modality therapy; clinical investigation of the effectiveness of short

  5. Acute renal failure in premature neonates

    Directory of Open Access Journals (Sweden)

    Doronjski Aleksandra

    2009-01-01

    Full Text Available Background/Aim. Hemodynamic stress is the leading cause of acute renal failure (ARF in premature neonates. Incidence of ARF in this population is between 8 and 24%. The aim of this study was to determine the frequency of presence of ARF in premature neonates, as well as its impact on their survival. Methods. A retrospective study of 114 premature neonates [(gestational age, GA less than 37 gestation weeks (gw] admitted to the Intensive Care Unit (ICU at the Pediatric Clinic, Institute of Child and Youth Healthcare of Vojvodina in 2007 was conducted. Serum creatinine, urea and bilirubine were determined on the 3rd day of life in 65 newborns who met inclusion criteria. ARF was diagnosed in 16 newborns (n=16/65; 25%. Results. The premature neonates with ARF had significantly lower GA [<28 gw - 8/16 (50% vs. 5/49 (10%; p < 0.05], birth weight (BW (1 265 g vs. 1615 g; p < 0.05 and systolic blood pressure (43.37 mm Hg vs. 52.7 mmHg; p < 0.05 than ones without ARF. Non-olyguric ARF was diagnosed in 62% of newborns with ARF (n=10/16, while the rest had the olyguric type (n = 6/16; 38%. Twenty-five percent of premature neonates with ARF (n = 4/16 died in contrast to 10% of premature neonates without ARF (n = 5/49. ARF was treated conservatively in all but 3 cases when peritoneal dialysis was performed. Renal function has recovered completely in all of the survivors. In order to determine their predictivity in relation to ARF, following parameters were analyzed: GA, BW < 1 500 g, presence of concomitant sepsis and intracranial hemorrhage grade III/IV. BW < 1 500 g demonstrated the highest sensitivity (se 0.75, while GA < 28 gw, sepsis and intracranial hemorrhage grade III/IV showed high specificity (sp = 0.90, 0.89 0.88, respectively. Conclusion. Acute renal failure frequently occurs in population of premature neonates and requires meticulous fluid and electrolyte balance, especially in the case of low birth weight and extreme immaturity.

  6. Prostanoid receptors involved in regulation of the beating rate of neonatal rat cardiomyocytes.

    Directory of Open Access Journals (Sweden)

    Hakima Mechiche

    Full Text Available Although prostanoids are known to be involved in regulation of the spontaneous beating rate of cultured neonatal rat cardiomyocytes, the various subtypes of prostanoid receptors have not been investigated in detail. In our experiments, prostaglandin (PGF(2α and prostanoid FP receptor agonists (fluprostenol, latanoprost and cloprostenol produced a decrease in the beating rate. Two prostanoid IP receptor agonists (iloprost and beraprost induced first a marked drop in the beating rate and then definitive abrogation of beating. In contrast, the prostanoid DP receptor agonists (PGD(2 and BW245C and TP receptor agonists (U-46619 produced increases in the beating rate. Sulprostone (a prostanoid EP(1 and EP(3 receptor agonist induced marked increases in the beating rate, which were suppressed by SC-19220 (a selective prostanoid EP(1 antagonist. Butaprost (a selective prostanoid EP(2 receptor agonist, misoprostol (a prostanoid EP(2 and EP(3 receptor agonist, 11-deoxy-PGE(1 (a prostanoid EP(2, EP(3 and EP(4 receptor agonist did not alter the beating rate. Our results strongly suggest that prostanoid EP(1 receptors are involved in positive regulation of the beating rate. Prostanoid EP(1 receptor expression was confirmed by western blotting with a selective antibody. Hence, neonatal rat cardiomyocytes express both prostanoid IP and FP receptors (which negatively regulate the spontaneous beating rate and prostanoid TP, DP(1 and EP(1 receptors (which positively regulate the spontaneous beating rate.

  7. Healthcare performance and the effects of the binaural beats on human blood pressure and heart rate.

    Science.gov (United States)

    Carter, Calvin

    2008-01-01

    Binaural beats are the differences in two different frequencies (in the range of 30-1000 Hz). Binaural beats are played through headphones and are perceived by the superior olivary nucleus of each hemisphere of the brain. The brain perceives the binaural beat and resonates to its frequency (frequency following response). Once the brain is in tune with the binaural beat it produces brainwaves of that frequency altering the listener's state of mind. In this experiment, the effects of the beta and theta binaural beat on human blood pressure and pulse were studied. Using headphones, three sounds were played for 7 minutes each to 12 participants: the control,- the sound of a babbling brook (the background sound to the two binaural beats), the beta binaural beat (20 Hz), and the theta binaural beat (7 Hz). Blood pressure and pulse were recorded before and after each sound was played. Each participant was given 2 minutes in-between each sound. The results showed that the control and the two binaural beats did not affect the 12 participant's blood pressure or pulse (p > 0.05). One reason for this may be that the sounds were not played long enough for the brain to either perceive and/or resonate to the frequency. Another reason why the sounds did not affect blood pressure and pulse may be due to the participant's age since older brains may not perceive the binaural beats as well as younger brains.

  8. Neural Entrainment and Sensorimotor Synchronization to the Beat in Children with Developmental Dyslexia: An EEG Study

    Directory of Open Access Journals (Sweden)

    Lincoln J. Colling

    2017-07-01

    Full Text Available Tapping in time to a metronome beat (hereafter beat synchronization shows considerable variability in child populations, and individual differences in beat synchronization are reliably related to reading development. Children with developmental dyslexia show impairments in beat synchronization. These impairments may reflect deficiencies in auditory perception of the beat which in turn affect auditory-motor mapping, or may reflect an independent motor deficit. Here, we used a new methodology in EEG based on measuring beat-related steady-state evoked potentials (SS-EPs, Nozaradan et al., 2015 in an attempt to disentangle neural sensory and motor contributions to behavioral beat synchronization in children with dyslexia. Children tapped with both their left and right hands to every second beat of a metronome pulse delivered at 2.4 Hz, or listened passively to the beat. Analyses of preferred phase in EEG showed that the children with dyslexia had a significantly different preferred phase compared to control children in all conditions. Regarding SS-EPs, the groups differed significantly for the passive Auditory listening condition at 2.4 Hz, and showed a trend toward a difference in the Right hand tapping condition at 3.6 Hz (sensorimotor integration measure. The data suggest that neural rhythmic entrainment is atypical in children with dyslexia for both an auditory beat and during sensorimotor coupling (tapping. The data are relevant to a growing literature suggesting that rhythm-based interventions may help language processing in children with developmental disorders of language learning.

  9. Impact of rotavirus vaccine on premature infants.

    Science.gov (United States)

    Roué, Jean-Michel; Nowak, Emmanuel; Le Gal, Grégoire; Lemaitre, Thomas; Oger, Emmanuel; Poulhazan, Elise; Giroux, Jean-Dominique; Garenne, Armelle; Gagneur, Arnaud

    2014-10-01

    Infants born preterm are at a higher risk of complications and hospitalization in cases of rotavirus diarrhea than children born at term. We evaluated the impact of a rotavirus vaccination campaign (May 2007 to May 2010) on hospitalizations for rotavirus gastroenteritis in a population of children under 3 years old born prematurely (before 37 weeks of gestation) in the Brest University Hospital birth zone. Active surveillance from 2002 to 2006 and a prospective collection of hospitalizations for rotavirus diarrhea were initiated in the pediatric units of Brest University Hospital until May 2010. Numbers of hospitalizations for rotavirus diarrhea among the population of children born prematurely, before and after the start of the vaccination program, were compared using a Poisson regression model controlling for epidemic-to-epidemic variation. A total of 217 premature infants were vaccinated from 2007 to 2010. Vaccine coverage for a complete course of three doses was 41.9%. The vaccine safety in premature infants was similar to that in term infants. The vaccination program led to a division by a factor of 2.6 (95% confidence interval [CI], 1.3 to 5.2) in the number of hospitalizations for rotavirus diarrhea during the first two epidemic seasons following vaccine introduction and by a factor of 11 (95% CI, 3.5 to 34.8) during the third season. We observed significant effectiveness of the pentavalent rotavirus vaccine on the number of hospitalizations in a population of prematurely born infants younger than 3 years of age. A multicenter national study would provide better assessment of this impact. (This study [Impact of Systematic Infants Vaccination Against Rotavirus on Gastroenteritis Hospitalization: a Prospective Study in Brest District, France (IVANHOE)] has been registered at ClinicalTrials.gov under registration no. NCT00740935.).

  10. Evaluation of a morphological filter in mean cardiac output determination: application to left ventricular assist devices.

    Science.gov (United States)

    Stevens, Michael Charles; Bradley, Andrew P; Wilson, Stephen J; Mason, David Glen

    2013-08-01

    A morphological filter (MF) is presented for the determination of beat-to-beat mean rotary left ventricular assist device (LVAD) flow rate, measured using an implanted flow probe. The performance of this non-linear filter was assessed using LVAD flow rate (QLVAD) data sets obtained from in silico and in vivo sources. The MF was compared with a third-order Butterworth filter (BWF) and a 10-s moving average filter (MAF). Performance was assessed by calculating the response time and steady state error across a range of heart rates and levels of noise. The response time of the MF was 3.5 times faster than the MAF, 0.5 s slower than the BWF, and had a steady state error of 2.61 %. It completely removed pulsatile signal components caused by residual ventricular function, and tracked sharp transient changes in QLVAD better than the BWF. The use of a two-stage MF improved the noise immunity compared to the single-stage MF. This study showed that the good performance characteristics of the non-linear MF make it a more suitable candidate for embedded real-time processing of QLVAD than linear filters.

  11. Birthing and Parenting a Premature Infant in a Cultural Context

    Science.gov (United States)

    Brooks, Jada L.; Holdtich-Davis, Diane; Docherty, Sharron L.; Theodorou, Christina S.

    2015-01-01

    The purpose of this longitudinal qualitative descriptive study was to explore American Indian (AI) mothers’ perceptions of parenting their premature infants over their first year of life in the context of their culture, including the birth and hospitalization experience. A convenience sample of 17 AI mothers and their premature infants were recruited from either a neonatal intensive care unit (NICU) or pediatric clinic in the southeast. Semistructured interviews were conducted at two time points. Through content analytic methods, three broad categories were revealed: descriptions of having a premature infant in the NICU, descriptions of parenting a premature infant, and the influence of Lumbee culture on parenting a premature infant. Certain aspects of AI culture appear to be important in having a premature infant in the NICU and in parenting a premature infant. We recommend that healthcare providers deliver culturally appropriate care that fully supports AI mothers and their premature infants. PMID:25721716

  12. Birthing and Parenting a Premature Infant in a Cultural Context.

    Science.gov (United States)

    Brooks, Jada L; Holdtich-Davis, Diane; Docherty, Sharron L; Theodorou, Christina S

    2016-02-01

    The purpose of this longitudinal qualitative descriptive study was to explore American Indian mothers' perceptions of parenting their premature infants over their first year of life in the context of their culture, including the birth and hospitalization experience. A convenience sample of 17 American Indian mothers and their premature infants were recruited from either a neonatal intensive care unit (NICU) or pediatric clinic in the southeast. Semistructured interviews were conducted at two time points. Through content analytic methods, three broad categories were revealed: descriptions of having a premature infant in the NICU, descriptions of parenting a premature infant, and the influence of Lumbee culture on parenting a premature infant. Certain aspects of American Indian culture appear to be important in having a premature infant in the NICU and in parenting a premature infant. We recommend that health care providers deliver culturally appropriate care that fully supports American Indian mothers and their premature infants. © The Author(s) 2015.

  13. The Reproducibility and Absolute Values of Echocardiographic Measurements of Left Ventricular Size and Function in Children are Algorithm Dependent

    Science.gov (United States)

    Margossian, Renee; Chen, Shan; Sleeper, Lynn A.; Tani, Lloyd Y.; Shirali, Girish; Golding, Fraser; Tierney, Elif Seda Selamet; Altmann, Karen; Campbell, Michael J.; Szwast, Anita; Sharkey, Angela; Radojewski, Elizabeth; Colan, Steven D.

    2015-01-01

    Background Several quantification algorithms for measuring left ventricular (LV) size and function are used in clinical and research settings. We investigated the effect of the measurement algorithm and beat averaging on the reproducibility of measurements of the LV and assessed the magnitude of agreement among the algorithms in children with dilated cardiomyopathy (DCM). Methods Echocardiograms were obtained on 169 children from 8 clinical centers. Inter- and intra-reader reproducibility were assessed on measurements of LV volumes using biplane Simpson, modified Simpson (MS), and 5/6 x area x length (5/6AL) algorithms. Percent error (%error) was calculated as the inter- or intra-reader difference / mean x 100. Single beat measurements and the 3-beat average (3BA) were compared. Intra-class correlation coefficients (ICC) were calculated to assess agreement. Results Single beat inter-reader reproducibility was lowest (%error was highest) using biplane Simpson; 5/6AL and MS were similar but significantly better than biplane Simpson (p 0.95 across measures, although absolute volume and mass values were systematically lower for biplane Simpson compared to MS and to 5/6AL. Conclusions The reproducibility of LV size and function measurements in children with DCM is highest using the 5/6AL algorithm, and can be further improved by using 3BA. However, values derived from different algorithms are not interchangeable. PMID:25728351

  14. Induction of chagasic-like arrhythmias in the isolated beating hearts of healthy rats perfused with Trypanosoma cruzi-conditioned medium

    Directory of Open Access Journals (Sweden)

    H. Rodriguez-Angulo

    2013-01-01

    Full Text Available Chagas' myocardiopathy, caused by the intracellular protozoan Trypanosoma cruzi, is characterized by microvascular alterations, heart failure and arrhythmias. Ischemia and arrythmogenesis have been attributed to proteins shed by the parasite, although this has not been fully demonstrated. The aim of the present investigation was to study the effect of substances shed by T. cruzi on ischemia/reperfusion-induced arrhythmias. We performed a triple ischemia-reperfusion (I/R protocol whereby the isolated beating rat hearts were perfused with either Vero-control or Vero T. cruzi-infected conditioned medium during the different stages of ischemia and subsequently reperfused with Tyrode's solution. ECG and heart rate were recorded during the entire experiment. We observed that triple I/R-induced bradycardia was associated with the generation of auricular-ventricular blockade during ischemia and non-sustained nodal and ventricular tachycardia during reperfusion. Interestingly, perfusion with Vero-infected medium produced a delay in the reperfusion-induced recovery of heart rate, increased the frequency of tachycardic events and induced ventricular fibrillation. These results suggest that the presence of parasite-shed substances in conditioned media enhances the arrhythmogenic effects that occur during the I/R protocol.

  15. Left ventricular twist is load-dependent as shown in a large animal model with controlled cardiac load

    Directory of Open Access Journals (Sweden)

    A’roch Roman

    2012-06-01

    Full Text Available Abstract Background Left ventricular rotation and twist can be assessed noninvasively by speckle tracking echocardiography. We sought to characterize the effects of acute load change and change in inotropic state on rotation parameters as a measure of left ventricular (LV contractility. Methods Seven anesthetised juvenile pigs were studied, using direct measurement of left ventricular pressure and volume and simultaneous transthoracic echocardiography. Transient inflation of an inferior vena cava balloon (IVCB catheter produced controlled load reduction. First and last beats in the sequence of eight were analysed with speckle tracking (STE during the load alteration and analysed for change in rotation/twist during controlled load alteration at same contractile status. Two pharmacological inotropic interventions were also included to examine the same hypothesis in additionally conditions of increased and decreased myocardial contractility in each animal. Paired comparisons were made for different load states using the Wilcoxon’s Signed Rank test. Results The inferior vena cava balloon occlusion (IVCBO load change compared for first to last beat resulted in LV twist increase (11.67° ±2.65° vs. 16.17° ±3.56° respectively, p  Conclusions Peak systolic LV twist and peak early diastolic untwisting rate are load dependent. Differences in LV load should be included in the interpretation when serial measures of twist are compared.

  16. Positive end-expiratory pressure (PEEP) does not depress left ventricular function in patients with pulmonary edema

    Energy Technology Data Exchange (ETDEWEB)

    Calvin, J.E.; Driedger, A.A.; Sibbald, W.J.

    1981-08-01

    Researchers evaluated the effects of positive end-expiratory pressure (PEEP) on left ventricular function in 15 patients with acute respiratory insufficiency secondary to pulmonary edema with invasive (pressure; flow) measurements and radionuclide angiography (RA). Using RNA allowed a definition of the left ventricular ejection fraction (LVEF), and then calculation of the left ventricular end-diastolic volume (LVEDV), both before and after PEEP. With a mean PEEP of 14.2 +/- 1.8 cm H2O (mean +/- SD) (range, 10 to 15), a fall in the cardiac index (4.34 +/- 1.5 to 3.84 +/- 1.4 L/min/M2; p less than 0.001) was accompanied by a significant decrease in the stroke volume index (42 +/- 13 to 39 +/- 12 ml/beat M2; p less than 0.01) and pulse rate (103.4 +/- 14.3 to 98 +/- 13.5 beats/min; p less than 0.01). The decrease in the stroke volume index was primarily due to a significant decrease in left ventricular preload (LVEDV) from 85.9 +/- 19 to 71.4 +/- 21.4 ml/m2 (p less than 0.01). Simultaneously, the mean LVEF increased from 0.47 +/- 0.10 to 0.53 +/- 0.08 (p less than 0.05), despite a significant increase in the systemic vascular resistance (1,619 +/- 575 to 1,864 +/- 617 dynes . s. cm-5/M2; p less than 0.01). Researchers concluded that the use of PEEP in patients with acute pulmonary edema, to the degree used in this study, may depress cardiac output by simply decreasing left ventricular preload. Researchers were unable to produce any evidence that would support a change in the contractile state of the left ventricle as a cause of depressed forward flow with the use of PEEP.

  17. Alterations in Functional Connectivity for Language in Prematurely Born Adolescents

    Science.gov (United States)

    Schafer, Robin J.; Lacadie, Cheryl; Vohr, Betty; Kesler, Shelli R.; Katz, Karol H.; Schneider, Karen C.; Pugh, Kenneth R.; Makuch, Robert W.; Reiss, Allan L.; Constable, R. Todd; Ment, Laura R.

    2009-01-01

    Recent data suggest recovery of language systems but persistent structural abnormalities in the prematurely born. We tested the hypothesis that subjects who were born prematurely develop alternative networks for processing language. Subjects who were born prematurely (n = 22; 600-1250 g birth weight), without neonatal brain injury on neonatal…

  18. 14 CFR 1214.806 - Premature termination of Spacelab flights.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Premature termination of Spacelab flights... FLIGHT Reimbursement for Spacelab Services § 1214.806 Premature termination of Spacelab flights. If a... are, in NASA's judgment, adversely affected by such premature termination. The basis for proration...

  19. Beat map drawing method for large oriental bell based on operational deflection shape method

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joong Hyeok; Kim, Seock Hyun [Dept. of Advanced Mechanical Engineering, Kangwon National University, Chuncheon (Korea, Republic of); Park, In Seok [TB Tires Development 1 Team, R and D Center, Kumho Tire, Yongin (Korea, Republic of)

    2016-10-15

    Oriental bells produce a peculiar sound in the form of beats, which are periodic repetitions of strong and weak sounds. A beating sound with a proper period gives the illusion of the bell being alive and breathing. To produce a good beating sound, appropriate modal parameters are required for beat tuning after casting the bell. Conventionally, modal parameters were extracted using frequency response functions of the excitation and response signals. However, a large oriental bell is usually struck by a heavy wooden hammer and hence, only the response signal can be measured. In this study, we extract the modal parameters using the response signal only and employ the data to predict the beat properties of the bell sound. Finally, the validity of the predicted beat properties is experimentally verified for a large oriental bell.

  20. Dynamic curvature regulation accounts for the symmetric and asymmetric beats of Chlamydomonas flagella

    CERN Document Server

    Sartori, Pablo; Scholich, Andre; Jülicher, Frank; Howard, Jonathon

    2015-01-01

    Axonemal dyneins are the molecular motors responsible for the beating of cilia and flagella. These motors generate sliding forces between adjacent microtubule doublets within the axoneme, the motile cytoskeletal structure inside the flagellum. To create regular, oscillatory beating patterns, the activities of the axonemal dyneins must be coordinated both spatially and temporally. It is thought that coordination is mediated by stresses or strains that build up within the moving axoneme, but it is not known which components of stress or strain are involved, nor how they feed back on the dyneins. To answer this question, we used isolated, reactivate axonemes of the unicellular alga Chlamydomonas as a model system. We derived a theory for beat regulation in a two-dimensional model of the axoneme. We then tested the theory by measuring the beat waveforms of wild type axonemes, which have asymmetric beats, and mutant axonemes, in which the beat is nearly symmetric, using high-precision spatial and temporal imaging....

  1. Synchronous Optical Pumping of Quantum Revival Beats for Atomic Magnetometery

    CERN Document Server

    Seltzer, S J; Romalis, M V

    2006-01-01

    We observe quantum beats with periodic revivals due to non-linear spacing of Zeeman levels in the ground state of potassium atoms and demonstrate their synchronous optical pumping by double modulation of the pumping light at the Larmor frequency and the revival frequency. We show that synchronous pumping increases the degree of spin polarization by a factor of 4. As a practical example, we explore the application of this double-modulation technique to atomic magnetometers operating in the geomagnetic field range and find that it can increase the sensitivity and reduce magnetic field orientation-dependent measurement errors endemic to alkali-metal magnetometers.

  2. How to beat the sphere-packing bound with feedback

    OpenAIRE

    Sahai, Anant

    2006-01-01

    The sphere-packing bound $E_{sp}(R)$ bounds the reliability function for fixed-length block-codes. For symmetric channels, it remains a valid bound even when strictly causal noiseless feedback is allowed from the decoder to the encoder. To beat the bound, the problem must be changed. While it has long been known that variable-length block codes can do better when trading-off error probability with expected block-length, this correspondence shows that the {\\em fixed-delay} setting also present...

  3. Can compressed sensing beat the Nyquist sampling rate?

    CERN Document Server

    Yaroslavsky, L

    2015-01-01

    Data saving capability of "Compressed sensing (sampling)" in signal discretization is disputed and found to be far below the theoretical upper bound defined by the signal sparsity. On a simple and intuitive example, it is demonstrated that, in a realistic scenario for signals that are believed to be sparse, one can achieve a substantially larger saving than compressing sensing can. It is also shown that frequent assertions in the literature that "Compressed sensing" can beat the Nyquist sampling approach are misleading substitution of terms and are rooted in misinterpretation of the sampling theory.

  4. On the quantum beats in mesoscopic loop structures

    Energy Technology Data Exchange (ETDEWEB)

    Tralle, I.; Pasko, W

    2003-11-17

    A simple theory of quantum interference phenomenon, quantum beats which are due to Larmor precession of spins in mesoscopic structure, is presented. The similarities between this effect and Josephson, scalar Aharonov-Bohm and Aharonov-Casher effects, as well as their differences are considered. Possible application of the effect to the construction of the device, complementary to SQUID's is discussed. Such device could be useful for measuring the slightest magnetic field deviations from the spatial uniformity in extremely small scale.

  5. QUANTUM BEATS OF RECOIL-FREE γ-RADIATION

    OpenAIRE

    Perlow, G.; Monahan, J.; Potzel, W.

    1980-01-01

    The radiation from a Mössbauer source of 57Co in a copper matrix is frequency-modulated by vibrating the source with a quartz piezo-crystal driven by an oscillator. If the radiation passes through a resonant absorber (a "filter"), a time structure containing the oscillator frequency and its harmonics appears in the resulting counting rate. It may be seen by sorting the time of each count with respect to the cross-over time of a subharmonic of the oscillator. These quantum beats are caused by ...

  6. Different Rebellions--The and the Angry Beat Generation Man

    Institute of Scientific and Technical Information of China (English)

    欧国芳

    2012-01-01

    The Beat Generation (BG) and the Angry Man (AYM) both emerged after the Second World War. Thus, the misunderstanding of the two has existed for a long time. Large quantities of people called the BG the American Angry Young Man. Undoubtedly, the two resembled each other to some extent. However, the BG and the AYM can't be treated alike, for their differences far outweighed their similarities. This paper aims to analyze their differences in many aspects like the national environment and their memberships, which consequently led to other differences such as the differences in essences, features, influence and finale.

  7. Modulation of attosecond beating by resonant two-photon transition

    CERN Document Server

    Galán, Álvaro Jiménez; Martín, Fernando

    2015-01-01

    We present an analytical model that characterizes two-photon transitions in the presence of autoionising states. We applied this model to interpret resonant RABITT spectra, and show that, as a harmonic traverses a resonance, the phase of the sideband beating significantly varies with photon energy. This phase variation is generally very different from the $\\pi$ jump observed in previous works, in which the direct path contribution was negligible. We illustrate the possible phase profiles arising in resonant two-photon transitions with an intuitive geometrical representation.

  8. Matrix Organisation : The design of cross-beat teamwork in newsrooms

    OpenAIRE

    Grubenmann, Stephanie

    2016-01-01

    Confronted by increased internal and external complexity, traditional forms of newswork have reached their limits. Journalistic start-ups, such as Quartz and NZZ.at, form emerging editorial teams around "obsessions" or "phenomena" to gain cross-beat perspectives of complex issues such as climate change, the financial crisis or the refugee crisis. Legacy media experimenting with cross-beat newswork see themselves confronted by challenges arising predominantly from beat structures. Consequently...

  9. Response of cat inferior colliculus neurons to binaural beat stimuli: possible mechanisms for sound localization.

    Science.gov (United States)

    Kuwada, S; Yin, T C; Wickesberg, R E

    1979-11-02

    The interaural phase sensitivity of neurons was studied through the use of binaural beat stimuli. The response of most cells was phase-locked to the beat frequency, which provides a possible neural correlate to the human sensation of binaural beats. In addition, this stimulus allowed the direction and rate of interaural phase change to be varied. Some neurons in our sample responded selectively to manipulations of these two variables, which suggests a sensitivity to direction or speed of movement.

  10. The Effect of Binaural Beats on Visuospatial Working Memory and Cortical Connectivity

    OpenAIRE

    Beauchene, C.; Abaid, N; Moran, R.; Diana, RA; Leonessa, A

    2016-01-01

    Binaural beats utilize a phenomenon that occurs within the cortex when two different frequencies are presented separately to each ear. This procedure produces a third phantom binaural beat, whose frequency is equal to the difference of the two presented tones and which can be manipulated for non-invasive brain stimulation. The effects of binaural beats on working memory, the system in control of temporary retention and online organization of thoughts for successful goal directed behavior, hav...

  11. Individual differences in beat perception affect gait responses to low- and high-groove music.

    Directory of Open Access Journals (Sweden)

    Li-Ann eLeow

    2014-10-01

    Full Text Available Slowed gait in Parkinson’s disease (PD patients can be improved when patients synchronize footsteps to isochronous metronome cues, but limited retention of such improvements suggest that permanent cueing regimes are needed for long-term improvements. If so, music might make permanent cueing regimes more pleasant, improving adherence; however, music cueing requires patients to synchronize movements to the beat, which might be difficult for PD patients who tend to show weak beat perception. One solution may be to use high groove music, which has high beat salience that may facilitate synchronization, and affective properties which may improve motivation to move. As a first step in understanding how beat perception affects gait in complex neurological disorders, we examined how beat perception ability affected gait in neurotypical adults. Synchronization performance and gait parameters were assessed as healthy young adults with strong or weak beat perception synchronized to low groove music, high groove music, and metronome cues. High groove music was predicted to elicit better synchronization than low groove music, due to its higher beat salience. Two musical tempi, or rates, were used: (1 preferred tempo: beat rate matched to preferred step rate and (2 faster tempo: beat rate adjusted to 22.5% faster than preferred step rate. For both strong and weak beat-perceivers, synchronization performance was best with metronome cues, followed by high groove music, and worst with low groove music. In addition, high groove music elicited longer and faster steps than low groove music, both at preferred tempo and at faster tempo. Low groove music was particularly detrimental to gait in weak beat-perceivers, who showed slower and shorter steps compared to uncued walking. The findings show that individual differences in beat perception affect gait when synchronizing footsteps to music, and have implications for using music in gait rehabilitation.

  12. Individual differences in beat perception affect gait responses to low- and high-groove music.

    Science.gov (United States)

    Leow, Li-Ann; Parrott, Taylor; Grahn, Jessica A

    2014-01-01

    Slowed gait in patients with Parkinson's disease (PD) can be improved when patients synchronize footsteps to isochronous metronome cues, but limited retention of such improvements suggest that permanent cueing regimes are needed for long-term improvements. If so, music might make permanent cueing regimes more pleasant, improving adherence; however, music cueing requires patients to synchronize movements to the "beat," which might be difficult for patients with PD who tend to show weak beat perception. One solution may be to use high-groove music, which has high beat salience that may facilitate synchronization, and affective properties, which may improve motivation to move. As a first step to understanding how beat perception affects gait in complex neurological disorders, we examined how beat perception ability affected gait in neurotypical adults. Synchronization performance and gait parameters were assessed as healthy young adults with strong or weak beat perception synchronized to low-groove music, high-groove music, and metronome cues. High-groove music was predicted to elicit better synchronization than low-groove music, due to its higher beat salience. Two musical tempi, or rates, were used: (1) preferred tempo: beat rate matched to preferred step rate and (2) faster tempo: beat rate adjusted to 22.5% faster than preferred step rate. For both strong and weak beat-perceivers, synchronization performance was best with metronome cues, followed by high-groove music, and worst with low-groove music. In addition, high-groove music elicited longer and faster steps than low-groove music, both at preferred tempo and at faster tempo. Low-groove music was particularly detrimental to gait in weak beat-perceivers, who showed slower and shorter steps compared to uncued walking. The findings show that individual differences in beat perception affect gait when synchronizing footsteps to music, and have implications for using music in gait rehabilitation.

  13. Factors associated with wife beating in Egypt: Analysis of two surveys (1995 and 2005

    Directory of Open Access Journals (Sweden)

    Dhaher Enas

    2008-09-01

    Full Text Available Abstract Background Wife beating is an important public health problem in many developing countries. We assessed the rates of wife beating and examined factors associated with wife beating in 1995 and 2005 in Egypt. Methods We used data from two Demographic and Health Surveys (DHS conducted in Egypt in 1995 and 2005 using multistage household sampling. Data related to wife beating included information from 7122 women in 1995 and 5612 women in 2005. Logistic regression was used to analyze factors independently associated with wife beating. Special weights were used to obtain nationally representative estimates. Results In 1995 17.5% of married women in Egypt experienced wife beating in the last 12 months, in 2005 – 18.9% or 16.0%, using different measures. The association between socio-demographic differentials and wife beating was weaker in the newer survey. The 12-month prevalence of wife beating was lower only when both partners were educated, but the differences across education levels were less pronounced in 2005. Based on the information available in the 2005 survey, more educated women experienced less severe forms of wife beating than less educated women. Conclusion Different measures used in both surveys make a direct comparison difficult. The observed patterns indicate that the changes in prevalence may be masked by two opposite processes occurring in the society: a decrease in (severe forms of wife beating and an increase in reporting of wife beating. Improving the access to education for women and raising education levels in the whole society may help reducing wife beating.

  14. Genetics Home Reference: arrhythmogenic right ventricular cardiomyopathy

    Science.gov (United States)

    ... Twitter Home Health Conditions ARVC arrhythmogenic right ventricular cardiomyopathy Printable PDF Open All Close All Enable Javascript ... the expand/collapse boxes. Description Arrhythmogenic right ventricular cardiomyopathy ( ARVC ) is a form of heart disease that ...

  15. Enhanced Timing Abilities in Percussionists Generalize to Rhythms Without a Musical Beat

    Directory of Open Access Journals (Sweden)

    Daniel J Cameron

    2014-12-01

    Full Text Available The ability to entrain movements to music is arguably universal, but it is unclear how specialized training may influence this. Previous research suggests that percussionists have superior temporal precision in perception and production tasks. Such superiority may be limited to temporal sequences that resemble real music or, alternatively, may generalize to musically implausible sequences. To test this, percussionists and nonpercussionists completed two tasks that used rhythmic sequences varying in musical plausibility. In the beat tapping task, participants tapped with the beat of a rhythmic sequence over 3 stages: finding the beat (as an initial sequence played, continuation of the beat (as a second sequence was introduced and played simultaneously, and switching to a second beat (the initial sequence finished, leaving only the second. The metres of the two sequences were either congruent or incongruent, as were their tempi (minimum inter-onset intervals. In the rhythm reproduction task, participants reproduced rhythms of four types, ranging from high to low musical plausibility: Metric simple rhythms induced a strong sense of the beat, metric complex rhythms induced a weaker sense of the beat, nonmetric rhythms had no beat, and jittered nonmetric rhythms also had no beat as well as low temporal predictability. For both tasks, percussionists performed more accurately than nonpercussionists. In addition, both groups were better with musically plausible than implausible conditions. Overall, the percussionists’ superior abilities to entrain to, and reproduce, rhythms generalized to musically implausible sequences.

  16. Human cortical responses to slow and fast binaural beats reveal multiple mechanisms of binaural hearing

    National Research Council Canada - National Science Library

    Ross, Bernhard; Miyazaki, Takahiro; Thompson, Jessica; Jamali, Shahab; Fujioka, Takako

    2014-01-01

    .... To examine the neural representations underlying these different perceptions, we recorded neuromagnetic cortical responses while participants listened to binaural beats at a continuously varying rate...

  17. Enhanced timing abilities in percussionists generalize to rhythms without a musical beat.

    Science.gov (United States)

    Cameron, Daniel J; Grahn, Jessica A

    2014-01-01

    The ability to entrain movements to music is arguably universal, but it is unclear how specialized training may influence this. Previous research suggests that percussionists have superior temporal precision in perception and production tasks. Such superiority may be limited to temporal sequences that resemble real music or, alternatively, may generalize to musically implausible sequences. To test this, percussionists and nonpercussionists completed two tasks that used rhythmic sequences varying in musical plausibility. In the beat tapping task, participants tapped with the beat of a rhythmic sequence over 3 stages: finding the beat (as an initial sequence played), continuation of the beat (as a second sequence was introduced and played simultaneously), and switching to a second beat (the initial sequence finished, leaving only the second). The meters of the two sequences were either congruent or incongruent, as were their tempi (minimum inter-onset intervals). In the rhythm reproduction task, participants reproduced rhythms of four types, ranging from high to low musical plausibility: Metric simple rhythms induced a strong sense of the beat, metric complex rhythms induced a weaker sense of the beat, nonmetric rhythms had no beat, and jittered nonmetric rhythms also had no beat as well as low temporal predictability. For both tasks, percussionists performed more accurately than nonpercussionists. In addition, both groups were better with musically plausible than implausible conditions. Overall, the percussionists' superior abilities to entrain to, and reproduce, rhythms generalized to musically implausible sequences.

  18. Prematurity: an overview and public health implications.

    Science.gov (United States)

    McCormick, Marie C; Litt, Jonathan S; Smith, Vincent C; Zupancic, John A F

    2011-01-01

    The high rate of premature births in the United States remains a public health concern. These infants experience substantial morbidity and mortality in the newborn period, which translate into significant medical costs. In early childhood, survivors are characterized by a variety of health problems, including motor delay and/or cerebral palsy, lower IQs, behavior problems, and respiratory illness, especially asthma. Many experience difficulty with school work, lower health-related quality of life, and family stress. Emerging information in adolescence and young adulthood paints a more optimistic picture, with persistence of many problems but with better adaptation and more positive expectations by the young adults. Few opportunities for prevention have been identified; therefore, public health approaches to prematurity include assurance of delivery in a facility capable of managing neonatal complications, quality improvement to minimize interinstitutional variations, early developmental support for such infants, and attention to related family health issues.

  19. The genetic basis of premature ovarian failure.

    Science.gov (United States)

    Woad, Kathryn J; Watkins, Wendy J; Prendergast, Deborah; Shelling, Andrew N

    2006-06-01

    Premature ovarian failure (POF) is a common condition, affecting approximately 1:100 women. It is characterised by amenorrhea, hypoestrogenism, and elevated gonadotrophin levels in women under the age of 40. It is often an unexpected and distressing diagnosis, which coincides with infertility and menopausal symptoms. There is a well recognised genetic basis to the development of POF. Our laboratory has identified several candidate genes associated with POF.

  20. Progeria: A rare genetic premature ageing disorder

    OpenAIRE

    Jitendra Kumar Sinha; Shampa Ghosh; Manchala Raghunath

    2014-01-01

    Progeria is characterized by clinical features that mimic premature ageing. Although the mutation responsible for this syndrome has been deciphered, the mechanism of its action remains elusive. Progeria research has gained momentum particularly in the last two decades because of the possibility of revealing evidences about the ageing process in normal and other pathophysiological conditions. Various experimental models, both in vivo and in vitro, have been developed in an effort to understand...

  1. The drug treatment of premature ejaculation

    OpenAIRE

    Hisasue, Shin-ichi

    2016-01-01

    The management recommendation for both acquired premature ejaculation (APE) and lifelong PE (LPE) are similar, such as a behavioral/psychotherapy, a pharmacotherapy and a combination of these treatments. For the drug treatment for PE, gold standard is selective serotonin reuptake inhibitors (SSRIs) including dapoxetine or paroxetine. The drug treatment for PE is still developing and some new promising therapeutic options have been proposed. Topical anesthetics, tramadol, and alpha-1 blockers ...

  2. 21 CFR 882.4060 - Ventricular cannula.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ventricular cannula. 882.4060 Section 882.4060...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4060 Ventricular cannula. (a) Identification. A ventricular cannula is a device used to puncture the ventricles of the brain for aspiration...

  3. 21 CFR 882.4100 - Ventricular catheter.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ventricular catheter. 882.4100 Section 882.4100...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4100 Ventricular catheter. (a) Identification. A ventricular catheter is a device used to gain access to the cavities of the brain for...

  4. Analysis of the forces acting on beating cilia

    Science.gov (United States)

    Sangani, Ashok S.; Vidyadharan, Jyothish; Foster, Kenneth W.

    2016-06-01

    Detailed analysis of the forces acting on a uniform-diameter beating cilium is carried out to determine the moment generated by the inter-doublet forces acting along the length of a cilium and the results are compared with the sliding-control theory according to which the moment is a function of the interdoublet sliding. In the central part of the cilium the inter-doublet forces are found to be proportional to the inter-doublet sliding. However, in spite of the uniformity of the diameter of the cilium, the proportionality constant, known as the dynamic stiffness, is not constant along its entire length. Significant variations are observed in the regions both near the tip of the cilium and proximal to the cell body. In the tip region the magnitude of the dynamic stiffness is found to decrease. This decrease is probably due to decrease in the number density of the molecular motors in that region and in the number of doublet microtubules. The behavior in the proximal region, on the other hand, does not appear to be well described by the sliding control theory. Our analysis therefore suggests that the dynamics of ciliary beating cannot be adequately described by a simple sliding-control theory with constant dynamic stiffness. Our analysis suggests that the cilium is differentiated into a basal region optimized for the creation of a wave and a central region optimized to support a traveling wave that provides the thrust for the cell.

  5. A sensorimotor theory of temporal tracking and beat induction.

    Science.gov (United States)

    Todd, N P McAngus; Lee, C S; O'Boyle, D J

    2002-02-01

    In this paper, we develop a theory of the neurobiological basis of temporal tracking and beat induction as a form of sensory-guided action. We propose three principal components for the neurological architecture of temporal tracking: (1) the central auditory system, which represents the temporal information in the input signal in the form of a modulation power spectrum; (2) the musculoskeletal system, which carries out the action and (3) a controller, in the form of a parieto-cerebellar-frontal loop, which carries out the synchronisation between input and output by means of an internal model of the musculoskeletal dynamics. The theory is implemented in the form of a computational algorithm which takes sound samples as input and synchronises a simple linear mass-spring-damper system to simulate audio-motor synchronisation. The model may be applied to both the tracking of isochronous click sequences and beat induction in rhythmic music or speech, and also accounts for the approximate Weberian property of timing.

  6. Epicardial radiofrequency ablation on a beating heart: an experimental study.

    Science.gov (United States)

    Ishikawa, Susumu; Oki, Shigeru; Muraoka, Masato; Oshima, Kiyohiro; Kashiwabara, Kenji; Morishita, Yasuo

    2005-02-01

    The effect of epicardial radiofrequency ablation (RFA) during normal heart beating was experimentally studied in order to establish safe and effective procedures for RFA. Seven pigs weighing approximately 30 to 50 kg were used in this study. Fifty-one epicardial RFA lesions were created on both atria using a Cobra Cooled probe with continuous internal irrigation of a saline solution. The ablation temperature was fixed at 80 degrees C and the duration of the RFA in each case was 20, 30, 60 and 120 seconds. There was significant positive correlation between the right and left atria in wall thickness. Transmural coagulation was obtained in 69% of the total specimens, which decreased according to the increase of wall thickness especially over 3 mm. Transmural coagulation was seen in 64% of the specimens after RFA of less than 30 seconds, and 86% after ablation of >or=60 seconds. Occurence of 90% or deeper coagulation was higher in the right atrium than in the left one (97% vs. 78%). Right atrial rupture occurred in a region of 1 mm in thickness after ablation of 60 seconds. Further technical improvements associated with new instruments are indispensable to complete epicardial RFA procedures on a beating heart.

  7. Effect of Cilia Beat Frequency on Mucociliary Clearance

    Directory of Open Access Journals (Sweden)

    Sedaghat M. H.

    2016-12-01

    Full Text Available Background: The airway surface liquid (ASL, which is a fluid layer coating the interior epithelial surface of the bronchi and bronchiolesis, plays an important defensive role against foreign particles and chemicals entering lungs. Objective: Numerical investigation has been employed to solve two-layer model consisting of mucus layer as a viscoelastic fluid and periciliary liquid layer as a Newtonian fluid to study the effects of cilia beat frequency (CBF at various amounts of mucus properties on muco-ciliary transport problem. Methods: Hybrid finite difference-lattice Boltzmann-method (FB-LBM has been used to solve the momentum equations and to simulate cilia forces, and also the PCLmucus interface more accurately, immersed boundary method (IBM has been employed. The main contribution of the current study is to use an Oldroyd-B model as the constitutive equation of mucus. Results: Our results show that increasing CBF and decreasing mucus viscosity ratio have great effects on mucus flow, but the effect of viscosity ratio is more significant. The results also illustrate that the relation between cilia beat frequency and mean mucus velocity is almost linear and it has similar behavior at different values of viscosity ratio. Conclusion: Numerical investigation based on hybrid IB-FD-LBM has been used to study the effect of CBF at various mounts of mucus viscosity ratio on the muco-ciliary clearance. The results showed that the effect of viscosity ratio on the muco-ciliary transport process is more significant compared with CBF.

  8. Efficient heart beat detection using embedded system electronics

    Science.gov (United States)

    Ramasamy, Mouli; Oh, Sechang; Varadan, Vijay K.

    2014-04-01

    The present day bio-technical field concentrates on developing various types of innovative ambulatory and wearable devices to monitor several bio-physical, physio-pathological, bio-electrical and bio-potential factors to assess a human body's health condition without intruding quotidian activities. One of the most important aspects of this evolving technology is monitoring heart beat rate and electrocardiogram (ECG) from which many other subsidiary results can be derived. Conventionally, the devices and systems consumes a lot of power since the acquired signals are always processed on the receiver end. Because of this back end processing, the unprocessed raw data is transmitted resulting in usage of more power, memory and processing time. This paper proposes an innovative technique where the acquired signals are processed by a microcontroller in the front end of the module and just the processed signal is then transmitted wirelessly to the display unit. Therefore, power consumption is considerably reduced and clearer data analysis is performed within the module. This also avoids the need for the user to be educated about usage of the device and signal/system analysis, since only the number of heart beats will displayed at the user end. Additionally, the proposed concept also eradicates the other disadvantages like obtrusiveness, high power consumption and size. To demonstrate the above said factors, a commercial controller board was used to extend the monitoring method by using the saved ECG data from a computer.

  9. [Prematurity risk according to prematurity risk score and postpartal morbidity of the newborn infants (author's transl)].

    Science.gov (United States)

    Coradello, H; Lubec, G; Simbruner, G

    1981-02-01

    Risk of premature birth was evaluated retrospectively in 610 women in the first days after delivery using the prematurity risk score published by Thalhammer 1973. The calculated risk of premature birth was compared than prospectively to postpartal morbidity of the newborn infants as determined by duration of hospital stay, incidence of respiratory distress syndrome, need of artificial ventilation and mortality. A positive correlation could be found between risk of premature birth and postpartal morbidity of the newborn infants especially in small premature infants with birthweights of 2000 grams and less. The same correlation existed also in two groups of infants out of two different obstetric clinics which showed the same distribution of prenatal risks and the same prenatal care frequencies. It clearly becomes evident that infants with the same prenatal risks but good prenatal care during pregnancy had much lower hospital stays, lower respiratory distress frequencies and lower mortality rates than babies delivered from pregnancies badly cared for. These prenatal care related differences in postpartum morbidity again were much more evident in infants out of lower birth weight classes.

  10. Facts about Ventricular Septal Defect

    Science.gov (United States)

    ... Living With Heart Defects Data & Statistics Tracking & Research Articles & Key Findings Free Materials Multimedia and Tools Links to Other Websites Information For... Media Policy Makers Facts about Ventricular Septal Defect Language: English Español (Spanish) Recommend on Facebook Tweet Share Compartir ...

  11. The incomplete bucindolol evaluation in acute myocardial infarction Trial (BEAT)

    DEFF Research Database (Denmark)

    Torp-Pedersen, Christian; Køber, Lars; Ball, Stephen

    2002-01-01

    The aim of this study was to evaluate the efficacy of adding the beta-blocker bucindolol to standard therapy shortly after a myocardial infarction in a high-risk population with reduced left ventricular function. METHODS: The study was planned to include 2000 patients with an enzyme confirmed...... myocardial infarction and severely reduced left ventricular function determined by echocardiography (corresponding to ejection fraction ... of bucindolol 0.88 (95% confidence limits 0.5-1.5; P=0.6). There were 9/4 (bucindolol/placebo, P=0.16) heart failure events and 5/17 (P=0.01) reinfarctions in the bucindolol/placebo groups. CONCLUSION: Due to early closure it is unknown whether bucindolol changes mortality in high-risk post myocardial infarct...

  12. The Effect of Dopaminergic Medication on Beat-Based Auditory Timing in Parkinson's Disease.

    Science.gov (United States)

    Cameron, Daniel J; Pickett, Kristen A; Earhart, Gammon M; Grahn, Jessica A

    2016-01-01

    Parkinson's disease (PD) adversely affects timing abilities. Beat-based timing is a mechanism that times events relative to a regular interval, such as the "beat" in musical rhythm, and is impaired in PD. It is unknown if dopaminergic medication influences beat-based timing in PD. Here, we tested beat-based timing over two sessions in participants with PD (OFF then ON dopaminergic medication) and in unmedicated control participants. People with PD and control participants completed two tasks. The first was a discrimination task in which participants compared two rhythms and determined whether they were the same or different. Rhythms either had a beat structure (metric simple rhythms) or did not (metric complex rhythms), as in previous studies. Discrimination accuracy was analyzed to test for the effects of beat structure, as well as differences between participants with PD and controls, and effects of medication (PD group only). The second task was the Beat Alignment Test (BAT), in which participants listened to music with regular tones superimposed, and responded as to whether the tones were "ON" or "OFF" the beat of the music. Accuracy was analyzed to test for differences between participants with PD and controls, and for an effect of medication in patients. Both patients and controls discriminated metric simple rhythms better than metric complex rhythms. Controls also improved at the discrimination task in the second vs. first session, whereas people with PD did not. For participants with PD, the difference in performance between metric simple and metric complex rhythms was greater (sensitivity to changes in simple rhythms increased and sensitivity to changes in complex rhythms decreased) when ON vs. OFF medication. Performance also worsened with disease severity. For the BAT, no group differences or effects of medication were found. Overall, these findings suggest that timing is impaired in PD, and that dopaminergic medication influences beat-based and non-beat

  13. Interacting cortical and basal ganglia networks underlying finding and tapping to the musical beat.

    Science.gov (United States)

    Kung, Shu-Jen; Chen, Joyce L; Zatorre, Robert J; Penhune, Virginia B

    2013-03-01

    Humans are able to find and tap to the beat of musical rhythms varying in complexity from children's songs to modern jazz. Musical beat has no one-to-one relationship with auditory features-it is an abstract perceptual representation that emerges from the interaction between sensory cues and higher-level cognitive organization. Previous investigations have examined the neural basis of beat processing but have not tested the core phenomenon of finding and tapping to the musical beat. To test this, we used fMRI and had musicians find and tap to the beat of rhythms that varied from metrically simple to metrically complex-thus from a strong to a weak beat. Unlike most previous studies, we measured beat tapping performance during scanning and controlled for possible effects of scanner noise on beat perception. Results showed that beat finding and tapping recruited largely overlapping brain regions, including the superior temporal gyrus (STG), premotor cortex, and ventrolateral PFC (VLPFC). Beat tapping activity in STG and VLPFC was correlated with both perception and performance, suggesting that they are important for retrieving, selecting, and maintaining the musical beat. In contrast BG activity was similar in all conditions and was not correlated with either perception or production, suggesting that it may be involved in detecting auditory temporal regularity or in associating auditory stimuli with a motor response. Importantly, functional connectivity analyses showed that these systems interact, indicating that more basic sensorimotor mechanisms instantiated in the BG work in tandem with higher-order cognitive mechanisms in PFC.

  14. Intracranial electroencephalography power and phase synchronization changes during monaural and binaural beat stimulation.

    Science.gov (United States)

    Becher, Ann-Katrin; Höhne, Marlene; Axmacher, Nikolai; Chaieb, Leila; Elger, Christian E; Fell, Juergen

    2015-01-01

    Auditory stimulation with monaural or binaural auditory beats (i.e. sine waves with nearby frequencies presented either to both ears or to each ear separately) represents a non-invasive approach to influence electrical brain activity. It is still unclear exactly which brain sites are affected by beat stimulation. In particular, an impact of beat stimulation on mediotemporal brain areas could possibly provide new options for memory enhancement or seizure control. Therefore, we examined how electroencephalography (EEG) power and phase synchronization are modulated by auditory stimulation with beat frequencies corresponding to dominant EEG rhythms based on intracranial recordings in presurgical epilepsy patients. Monaural and binaural beat stimuli with beat frequencies of 5, 10, 40 and 80 Hz and non-superposed control signals were administered with low amplitudes (60 dB SPL) and for short durations (5 s). EEG power was intracranially recorded from mediotemporal, temporo-basal and temporo-lateral and surface sites. Evoked and total EEG power and phase synchronization during beat vs. control stimulation were compared by the use of Bonferroni-corrected non-parametric label-permutation tests. We found that power and phase synchronization were significantly modulated by beat stimulation not only at temporo-basal, temporo-lateral and surface sites, but also at mediotemporal sites. Generally, more significant decreases than increases were observed. The most prominent power increases were seen after stimulation with monaural 40-Hz beats. The most pronounced power and synchronization decreases resulted from stimulation with monaural 5-Hz and binaural 80-Hz beats. Our results suggest that beat stimulation offers a non-invasive approach for the modulation of intracranial EEG characteristics. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  15. Repeated heart rate measurement and cardiovascular outcomes in left ventricular systolic dysfunction.

    Science.gov (United States)

    Hamill, Victoria; Ford, Ian; Fox, Kim; Böhm, Michael; Borer, Jeffrey S; Ferrari, Roberto; Komajda, Michel; Steg, Philippe Gabriel; Tavazzi, Luigi; Tendera, Michal; Swedberg, Karl

    2015-10-01

    Elevated resting heart rate is associated with increased cardiovascular risk, particularly in patients with left ventricular systolic dysfunction. Heart rate is not monitored routinely in these patients. We hypothesized that routine monitoring of heart rate would increase its prognostic value in patients with left ventricular systolic dysfunction. We analyzed the relationship between heart rate measurements and a range of adverse cardiovascular outcomes, including hospitalization for worsening heart failure, in the pooled placebo-treated patients from the morBidity-mortality EvAlUaTion of the If inhibitor ivabradine in patients with coronary disease and left ventricULar dysfunction (BEAUTIFUL) trial and Systolic Heart failure treatment with the If inhibitor ivabradine (SHIFT) Trial, using standard and time-varying covariate Cox proportional hazards models. By adjusting for other prognostic factors, models were fitted for baseline heart rate alone or for time-updated heart rate (latest heart rate) alone or corrected for baseline heart rate or for immediate previous time-updated heart rate. Baseline heart rate was strongly associated with all outcomes apart from hospitalization for myocardial infarction. Time-updated heart rate increased the strengths of associations for all outcomes. Adjustment for baseline heart rate or immediate previous time-updated heart rate modestly reduced the prognostic importance of time-updated heart rate. For hospitalization for worsening heart failure, each 5 beats/min increase in baseline heart rate and time-updated heart rate was associated with a 15% (95% confidence interval, 12-18) and 22% (confidence interval, 19-40) increase in risk, respectively. Even after correction, the prognostic value of time-updated heart rate remained greater. In patients with left ventricular systolic dysfunction, time-updated heart rate is more strongly related with adverse cardiovascular outcomes than baseline heart rate. Heart rate should be measured to

  16. Predictive value of electrical restitution in hypokalemia-induced ventricular arrhythmogenicity

    DEFF Research Database (Denmark)

    Osadchii, Oleg E; Larsen, Anders Peter; Olesen, Soren Peter

    2009-01-01

    the predictive value of electrical restitution in hypokalemia-induced arrhythmogenicity. We recorded monophasic APs and measured effective refractory periods (ERP) at distinct ventricular epicardial and endocardial sites and monitored volume-conducted ECG at baseline and after hypokalemic perfusion (2.5 mM K......The ventricular action potential (AP) shortens exponentially upon a progressive reduction of the preceding diastolic interval. Steep electrical restitution slopes have been shown to promote wavebreaks, thus contributing to electrical instability. The present study was designed to assess......(+) for 30 min) in isolated guinea pig heart preparations. The restitution of AP duration measured at 90% repolarization (APD(90)) was assessed after premature extrastimulus application at variable coupling stimulation intervals, and ERP restitution was assessed by measuring refractoriness over a wide range...

  17. Use of beat-to-beat cardiovascular variability data to determine the validity of sham therapy as the placebo control in osteopathic manipulative medicine research.

    Science.gov (United States)

    Henley, Charles E; Wilson, Thad E

    2014-11-01

    Osteopathic manipulative medicine researchers often use sham therapy as the placebo control during clinical trials. Optimally, the sham therapy should be a hands-on procedure that is perceptually indistinguishable from osteopathic manipulative treatment, does not create an effect on its own, and is not a treatment intervention. However, the sham therapy itself may often influence the outcome. The use of cardiovascular variability (eg, beat-to-beat heart rate variability) as a surrogate for the autonomic nervous system is one objective method by which to identify such an effect. By monitoring cardiovascular variability, investigators can assess autonomic nervous system activity as a response to the sham therapy and quickly determine whether or not the selected sham therapy is a true placebo control. The authors provide evidence for assessment of beat-to-beat heart rate variability as one method for assuring objectivity of sham therapy as a placebo control in osteopathic manipulative medicine research.

  18. Post-Pacing Abnormal Repolarization in Catecholaminergic Polymorphic Ventricular Tachycardia Associated with a Mutation in the Cardiac Ryanodine Receptor Gene (RyR2)

    Science.gov (United States)

    Nof, Eyal; Belhassen, Bernard; Arad, Michael; Bhuiyan, Zahurul A.; Antzelevitch, Charles; Rosso, Raphael; Fogelman, Rami; Luria, David; Eli-Ani, Dalia; Mannens, Marcel M.A.M.; Viskin, Sami; Eldar, Michael; Wilde, Arthur A.M.; Glikson, Michael

    2011-01-01

    Background Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an arrhythmogenic disease for which electrophysiological studies (EPS) have shown to be of limited value. Objective We present a CPVT family in which marked post-pacing repolarization abnormalities during EPS were the only consistent phenotypic manifestation of RyR2 mutation carriers. Methods The study was prompted by the observation of transient marked QT prolongation preceding initiation of ventricular fibrillation during atrial fibrillation in a boy with a family history of sudden cardiac death (SCD). Family members underwent exercise and pharmacologic ECG testing with epinephrine, adenosine and flecainide. Non-invasive clinical tests were normal in 10 patients evaluated, except for both epinephrine and exercise-induced ventricular arrhythmias in 1. EPS included bursts of ventricular pacing and programmed ventricular extrastimulation reproducing short-long sequences. Genetic screening involved direct sequencing of genes involved in LQTS as well as RyR2. Results Six patients demonstrated a marked increase in QT interval only in the first beat after cessation of ventricular pacing and/or extrastimulation. All 6 patients were found to have a heterozygous missense mutation (M4109R) in RyR2. Two of them, presenting with aborted SCD also had a second missense mutation (I406T- RyR2). Four family members without RyR2 mutations did not display prominent post-pacing QT changes. Conclusions M4109R- RyR2 is associated with a high incidence of SCD. The contribution of I406T to the clinical phenotype is unclear. In contrast to exercise testing, marked post-pacing repolarization changes in a single beat accurately predicted carriers of M4109R- RyR2 in this family. PMID:21699856

  19. Peak misdetection in heart-beat-based security : Characterization and tolerance

    NARCIS (Netherlands)

    Seepers, Robert M; Strydis, Christos; Peris-Lopez, Pedro; Sourdis, Ioannis; De Zeeuw, Chris I

    2014-01-01

    The Inter-Pulse-Interval (IPI) of heart beats has previously been suggested for security in mobile health (mHealth) applications. In IPI-based security, secure communication is facilitated through a security key derived from the time difference between heart beats. However, there currently exists no

  20. Keeping the Beat: A Large Sample Study of Bouncing and Clapping to Music

    Science.gov (United States)

    Tranchant, Pauline; Vuvan, Dominique T.; Peretz, Isabelle

    2016-01-01

    The vast majority of humans move in time with a musical beat. This behaviour has been mostly studied through finger-tapping synchronization. Here, we evaluate naturalistic synchronization responses to music–bouncing and clapping–in 100 university students. Their ability to match the period of their bounces and claps to those of a metronome and musical clips varying in beat saliency was assessed. In general, clapping was better synchronized with the beat than bouncing, suggesting that the choice of a specific movement type is an important factor to consider in the study of sensorimotor synchronization processes. Performance improved as a function of beat saliency, indicating that beat abstraction plays a significant role in synchronization. Fourteen percent of the population exhibited marked difficulties with matching the beat. Yet, at a group level, poor synchronizers showed similar sensitivity to movement type and beat saliency as normal synchronizers. These results suggest the presence of quantitative rather than qualitative variations when losing the beat. PMID:27471854