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Sample records for european heart rhythm

  1. European Heart Rhythm Association Summit report 2014.

    PubMed

    Sutton, Richard; Leclercq, Christophe; Kuck, Karl-Heinz

    2016-05-01

    Across Europe, the role of the welfare state is constantly being questioned and even eroded. At the same time, funding sources for post-graduate medical education and training are under attack as regulators review the working relationships between physicians and industry. Both of these issues have profound consequences for cardiologists and their patients, and were, therefore, chosen as the themes of the European Heart Rhythm Association (EHRA) 2014 Spring Summit held at Heart House, Sophia Antipolis, 25-26 March 2014. The meeting noted that some of the changes are already affecting patient care standards and that this is exacerbated by a reduction in research and education programmes. The principle conclusion was that EHRA must find better means of engagement with the authorities across Europe to ensure that its views are considered and that ethical patient care is preserved. Participants were particularly alarmed by the example from Sweden in which future healthcare planning appears to exclude the views of physicians, although this is not yet the case in other countries. The demand for greater transparency in relationships between physicians and industry was also discussed. Although intended to eliminate corruption, concern was expressed that such moves would cause long-term damage to education and research, threatening the future of congresses, whose role in these areas appears underestimated by the authorities. PMID:26467405

  2. Health economics and the European Heart Rhythm Association.

    PubMed

    Vardas, Panos; Boriani, Giuseppe

    2011-05-01

    The management of healthcare is becoming extremely complex in developed countries, as a result of increasing age of the population and increasing costs of care, coupled with diminishing resources due to global financial crisis. This situation threatens access to appropriate care, and a more or less explicit rationing of some types of treatment may occur in 'real world' clinical practice. This is particularly true for those treatments or interventions with a relatively high up-front cost, such as cardioverter defibrillators, devices for cardiac resynchronization therapy or ablation procedures for atrial fibrillation. The European Heart Rhythm Association (EHRA) is strongly convinced that the skills of electrophysiologists and cardiologists responsible for the management of rhythm disorders have to evolve, also embracing the knowledge of health economics, clinical epidemiology, health-care management and outcome research. These disciplines do not belong to what is considered as the conventional cultural background of physicians, but knowledge of comparative cost effectiveness and of other economic approaches nowadays appears fundamental for a dialogue with a series of stakeholders, such as policy makers, politicians, and administrators, involved in budgeting the activity of hospitals and health-care services, as well as in approaching health technology assessment. PMID:21518741

  3. Clinical management of arrhythmias in elderly patients: results of the European Heart Rhythm Association survey.

    PubMed

    Chen, Jian; Hocini, Mélèze; Larsen, Torben Bjerregaard; Proclemer, Alessandro; Sciaraffia, Elena; Blomström-Lundqvist, Carina

    2015-02-01

    The purpose of this survey was to assess clinical practice in management of cardiac arrhythmias in elderly patients (age ≥75 years) in the European countries. The data are based on an electronic questionnaire sent to the European Heart Rhythm Association Research Network members. Responses were received from 50 centres in 20 countries. The results of the survey have shown that management of cardiac arrhythmias is generally in accordance with the guidelines and consensus recommendations on management of cardiac arrhythmias, although there are some areas of variation, especially on age limit and exclusion of elderly patients for anticoagulation, ablation, and device therapy. PMID:25634939

  4. Heart Rhythm Society

    MedlinePlus

    ... Search: Education & Meetings Scientific Sessions Certified Education Courses & Online Learning Heart Rhythm On Demand Co-Sponsored & Endorsed Events ... Education & Meetings less Scientific Sessions Certified Education Courses & Online Learning Heart Rhythm On Demand Co-Sponsored & Endorsed Events ...

  5. Stroke and bleeding risk evaluation in atrial fibrillation: results of the European heart rhythm association survey.

    PubMed

    Larsen, Torben Bjerregaard; Potpara, Tatjana; Dagres, Nikolaos; Pison, Laurent; Estner, Heidi; Blomström-Lundqvist, Carina

    2014-05-01

    The aim of this European Heart Rhythm Association (EHRA) survey was to assess clinical practice in relation to stroke and bleeding risk evaluation in atrial fibrillation, particularly regarding the use of risk evaluation schemes, among members of the EHRA electrophysiology (EP) research network. In this EP Wire survey, we have provided some insights into current practice in Europe for the use of these risk assessment schemes. There were some obvious practice differences. However, reassuring information on current practice in Europe was evident, but more focus on renal function is warranted, especially facing the fact that novel oral anticoagulants are used for antithrombotic therapy. PMID:24798958

  6. Management of patients with ventricular tachycardia in Europe: results of the European Heart Rhythm Association survey.

    PubMed

    Chen, Jian; Todd, Derick M; Proclemer, Alessandro; Sciaraffia, Elena; Estner, Heidi L; Broadhurst, Paul; Blomström-Lundqvist, Carina

    2015-08-01

    The purpose of this European Heart Rhythm Association (EHRA) survey was to assess clinical practice in the management of ventricular tachycardia (VT). The data are based on an electronic questionnaire sent to the members of the EHRA Research Network. Responses were received from 31 centres in 16 countries. The results of the survey show that the management of VT is in general in accordance with guidelines. Antiarrhythmic drugs are still frequently used for VT treatment. In patients at high risk of sudden cardiac death, an implantable cardioverter-defibrillator is routinely recommended, while the treatment options vary for patients with moderate or low risk. A discreet attitude is adopted for catheter ablation in high-risk patients as demonstrated by a relatively low rate of catheter ablation. PMID:26273104

  7. Defibrillation testing at the time of implantable cardioverter defibrillator implantation: results of the European Heart Rhythm Association survey.

    PubMed

    Morgan, John M; Marinskis, Germanas

    2011-04-01

    This survey assesses the current practices of testing defibrillation function at the time of the first implanted cardioverter defibrillator placement. Responses have been collected from 57 European heart rhythm management centres. The results of the survey show an extraordinary inconsistency in the approaches to defibrillation testing (19.3% of responders report no testing at the time of implantation). A policy statement on this topic would help to improve patient care and unify the procedure according to evidence based data. PMID:21447521

  8. Current ablation techniques for persistent atrial fibrillation: results of the European Heart Rhythm Association Survey.

    PubMed

    Dagres, Nikolaos; Bongiorni, Maria Grazia; Larsen, Torben Bjerregaard; Hernandez-Madrid, Antonio; Pison, Laurent; Blomström-Lundqvist, Carina

    2015-10-01

    The aim of this survey was to provide insight into current practice regarding ablation of persistent atrial fibrillation (AF) among members of the European Heart Rhythm Association electrophysiology research network. Thirty centres responded to the survey. The main ablation technique for first-time ablation was stand-alone pulmonary vein isolation (PVI): in 67% of the centres for persistent but not long-standing AF and in 37% of the centres for long-standing persistent AF as well. Other applied techniques were ablation of fractionated electrograms, placement of linear lesions, stepwise approach until AF termination, and substrate mapping and isolation of low-voltage areas. However, the percentage of centres applying these techniques during first ablation did not exceed 25% for any technique. When stand-alone PVI was performed in patients with persistent but not long-standing AF, the majority (80%) of the centres used an irrigated radiofrequency ablation catheter whereas 20% of the respondents used the cryoballoon. Similar results were reported for ablation of long-standing persistent AF (radiofrequency 90%, cryoballoon 10%). Neither rotor mapping nor one-shot ablation tools were used as the main first-time ablation methods. Systematic search for non-pulmonary vein triggers was performed only in 10% of the centres. Most common 1-year success rate off antiarrhythmic drugs was 50-60%. Only 27% of the centres knew their 5-year results. In conclusion, patients with persistent AF represent a significant proportion of AF patients undergoing ablation. There is a shift towards stand-alone PVI being the primary choice in many centres for first-time ablation in these patients. The wide variation in the use of additional techniques and in the choice of endpoints reflects the uncertainties and lack of guidance regarding the most optimal approach. Procedural success rates are modest and long-term outcomes are unknown in most centres. PMID:26498718

  9. Find a Heart Rhythm Specialist

    MedlinePlus

    ... Search: Education & Meetings Scientific Sessions Certified Education Courses & Online Learning Heart Rhythm On Demand Co-Sponsored & Endorsed Events ... Education & Meetings less Scientific Sessions Certified Education Courses & Online Learning Heart Rhythm On Demand Co-Sponsored & Endorsed Events ...

  10. Diagnosis and management of patients with inherited arrhythmia syndromes in Europe: results of the European Heart Rhythm Association Survey.

    PubMed

    Hocini, Mélèze; Pison, Laurent; Proclemer, Alessandro; Larsen, Torben Bjerregaard; Madrid, Antonio; Blomström-Lundqvist, Carina

    2014-04-01

    Inherited arrhythmia disorders associated with structurally normal heart (i.e. long and short QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, early repolarization syndrome, idiopathic ventricular fibrillation) cause 10% of 1.1 million sudden deaths in Europe and the USA. The purpose of this European Heart Rhythm Association (EHRA) electrophysiology wire survey was to assess the European clinical practice adopted for the diagnosis and management of these disorders. The survey was based on an electronic questionnaire sent out to the EHRA Research Network centres. Responses were received from 50 centres in 23 countries. The results of the survey show that inherited arrhythmia syndromes have a relatively low burden and are diagnosed and managed in accordance with the current guidelines. However, more than 50% of centres do not participate in any existing registry underlining the need for establishing a pan-European registry of these disorders. PMID:24711616

  11. Cardioversion for atrial fibrillation in current European practice: results of the European Heart Rhythm Association survey.

    PubMed

    Hernández-Madrid, Antonio; Svendsen, Jesper Hastrup; Lip, Gregory Y H; Van Gelder, Isabelle C; Dobreanu, Dan; Blomstrom-Lundqvist, Carina

    2013-06-01

    This survey was conducted to provide an insight into the current clinical practice regarding the use of cardioversion for atrial fibrillation (AF) in Europe. Responses were received from 57 centres across Europe, 71.9% of which were university hospitals. For electrical cardioversion, general anaesthesia was managed by an anaesthesiologist in 73.9% of centres and by a cardiologist in 37%. In the majority of centres, electrical cardioversion was performed using a biphasic defibrillator (85.1%). Antiarrhythmic drugs were routinely prescribed prior to electrical cardioversion by 54.3% of hospitals. For pharmacological cardioversion in patients with no or minimal heart disease, the majority of centres (63.1%) chose intravenous flecainide or propafenone, whereas vernakalant was used by 35% of centres in patients with no or minimal-to-moderate structural heart disease. Most centres (71.7%) used a mandatory strategy of 3 weeks of oral anticoagulation prior to elective cardioversion in patients AF > 48 h, but 28.3% performed immediate cardioversion after a transoesophageal echocardiogram. Many centres are now performing electrical cardioversion on treatment with novel oral anticoagulants (up to 23.6% of cardioversions). PMID:23709570

  12. Current periprocedural management of ablation for atrial fibrillation in Europe: results of the European Heart Rhythm Association survey.

    PubMed

    Chen, Jian; Todd, Derick M; Hocini, Mélèze; Larsen, Torben Bjerregaard; Bongiorni, Maria Grazia; Blomström-Lundqvist, Carina

    2014-03-01

    The purpose of this EP Wire survey was to assess clinical practice in periprocedural management of atrial fibrillation ablation. This survey is based on an electronic questionnaire sent to the European Heart Rhythm Association Research Network members. Responses were received from 78 centres in 20 countries. The results of the survey have shown that periprocedural management is generally in accordance with guidelines and consensus recommendations on ablation for atrial fibrillation ablation, although there are some areas of variation. Differences between high- and low-volume centres are observed with respect to patient selection, antiarrhythmic drug management, and heparin bridging. PMID:24569891

  13. Work-up and management of lone atrial fibrillation: results of the European Heart Rhythm Association Survey.

    PubMed

    Pison, Laurent; Hocini, Mélèze; Potpara, Tatjana S; Todd, Derick; Chen, Jian; Blomström-Lundqvist, Carina

    2014-10-01

    The purpose of this European Heart Rhythm Association (EHRA) survey was to explore the work-up and management of lone atrial fibrillation (AF) among the European centres. Thirty-two European centres, all members of the EHRA electrophysiology (EP) research network, responded to this survey and completed the list of questions. The prevalence of lone AF has been reported to be ≤10% by 19 (60%) of the participating centres. The presence of isolated left atrial enlargement and left ventricular diastolic dysfunction represent heart disease according to 50 and 84% of the centres, respectively, and exclude the diagnosis of lone AF. Fifty-nine per cent of responders do not routinely consider genetic testing in lone AF patients. The initial therapeutic approach in symptomatic paroxysmal lone AF is antiarrhythmic drug therapy as reported by 31 (97%) of the centres. Pulmonary vein isolation only is the first ablation strategy for patients with symptomatic persistent lone AF at 27 (84%) of the responding centres. Assessment for sleep apnoea, obesity, and intensive sports activity in lone AF is performed at 27 (84%) centres. In conclusion, this EP Wire survey confirms that the term 'lone AF' is still used in daily practice. The work-up typically includes screening for known risk factors but not genetic testing. The preferred management of paroxysmal lone AF is rhythm control with antiarrhythmic drugs, whereas pulmonary vein isolation is the first ablation strategy for the majority of patients with symptomatic persistent lone AF. PMID:25267359

  14. Current practice for diagnosis and management of silent atrial fibrillation: results of the European Heart Rhythm Association survey.

    PubMed

    Dobreanu, Dan; Svendsen, Jesper Hastrup; Lewalter, Thorsten; Hernández-Madrid, Antonio; Lip, Gregory Y H; Blomström-Lundqvist, Carina

    2013-08-01

    Although it is well known that silent atrial fibrillation (AF) is associated with morbidity and mortality rates similar to those of symptomatic AF, no specific strategy for screening and management of this form of AF has been advocated. The purpose of this survey was to identify current practices for the diagnosis and management of silent AF. This survey is based on an electronic questionnaire sent to the European Heart Rhythm Association Research Network partners. Responses were received from 33 centres in 16 countries. The preferred screening methods for silent AF in patients with rhythm control by pharmacological therapy was 12-lead electrocardiogram (ECG) at outpatient visits (31.3%) and periodical 24 h Holter ECG recordings (34.4%), while after pulmonary vein isolation the corresponding figures were 6.3 and 65.6%, respectively. No consensus has been reached concerning the therapeutic approach for such patients. Most responders preferred rate control over rhythm control in patients with silent AF, although some favoured pulmonary vein isolation in young patients. However, oral anticoagulant therapy in patients at high thromboembolic risk was considered mandatory by most, provided that at least one episode of silent AF was documented, without recommending further investigations. The results of this survey have confirmed that there is currently no consensus regarding the screening and management of patients with silent AF and that clinical practice is not always consistent with the few existing evidence-based recommendations. PMID:23878150

  15. Personnel, equipment, and facilities for electrophysiological and catheter ablation procedures in Europe: results of the European Heart Rhythm Association Survey.

    PubMed

    Estner, Heidi L; Chen, Jian; Potpara, Tatjana; Proclemer, Alessandro; Todd, Derick; Blomström-Lundqvist, Carina

    2014-07-01

    Clinical electrophysiology (EP) and catheter ablation of arrhythmias are rapidly evolving in recent years. More than 50 000 catheter ablations are performed every year in Europe. Emerging indications, an increasing number of procedures, and an expected high quality require national and international standards as well as trained specialists. The purpose of this European Heart Rhythm Association (EHRA) survey was to assess the practice of requirements for EP personnel, equipment, and facilities in Europe. Responses to the questionnaire were received from 52 members of the EHRA research network. The survey involved high-, medium-, and low-volume EP centres, performing >400, 100-399, and under 100 implants per year, respectively. The following topics were explored: (i) EP personnel issues including balance between female and male operators, responsibilities within the EP department, age profiles, role and training of fellows, and EP nurses, (ii) the equipments available in the EP laboratories, (iii) source of patient referrals, and (iv) techniques used for ablation for different procedures including sedation, and peri-procedural use of anticoagulation and antibiotics. The survey reflects the current EP personnel situation characterized by a high training requirement and specialization. Arrhythmia sections are still most often part of cardiology departments and the head of cardiology is seldom a heart rhythm specialist. Currently, the vast majority of EP physicians are men, although in the subgroup of physicians younger than 40 years, the proportion of women is increasing. Uncertainty exists regarding peri-procedural anticoagulation, antibiotic prophylaxis, and the need for sedation during specific procedures. PMID:24966009

  16. Personalized management of atrial fibrillation: Proceedings from the fourth Atrial Fibrillation competence NETwork/European Heart Rhythm Association consensus conference.

    PubMed

    Kirchhof, Paulus; Breithardt, Günter; Aliot, Etienne; Al Khatib, Sana; Apostolakis, Stavros; Auricchio, Angelo; Bailleul, Christophe; Bax, Jeroen; Benninger, Gerlinde; Blomstrom-Lundqvist, Carina; Boersma, Lucas; Boriani, Giuseppe; Brandes, Axel; Brown, Helen; Brueckmann, Martina; Calkins, Hugh; Casadei, Barbara; Clemens, Andreas; Crijns, Harry; Derwand, Roland; Dobrev, Dobromir; Ezekowitz, Michael; Fetsch, Thomas; Gerth, Andrea; Gillis, Anne; Gulizia, Michele; Hack, Guido; Haegeli, Laurent; Hatem, Stephane; Häusler, Karl Georg; Heidbüchel, Hein; Hernandez-Brichis, Jessica; Jais, Pierre; Kappenberger, Lukas; Kautzner, Joseph; Kim, Steven; Kuck, Karl-Heinz; Lane, Deirdre; Leute, Angelika; Lewalter, Thorsten; Meyer, Ralf; Mont, Lluis; Moses, Gregory; Mueller, Markus; Münzel, Felix; Näbauer, Michael; Nielsen, Jens Cosedis; Oeff, Michael; Oto, Ali; Pieske, Burkert; Pisters, Ron; Potpara, Tatjana; Rasmussen, Lars; Ravens, Ursula; Reiffel, James; Richard-Lordereau, Isabelle; Schäfer, Herbert; Schotten, Ulrich; Stegink, Wim; Stein, Kenneth; Steinbeck, Gerhard; Szumowski, Lukasz; Tavazzi, Luigi; Themistoclakis, Sakis; Thomitzek, Karen; Van Gelder, Isabelle C; von Stritzky, Berndt; Vincent, Alphons; Werring, David; Willems, Stephan; Lip, Gregory Y H; Camm, A John

    2013-11-01

    The management of atrial fibrillation (AF) has seen marked changes in past years, with the introduction of new oral anticoagulants, new antiarrhythmic drugs, and the emergence of catheter ablation as a common intervention for rhythm control. Furthermore, new technologies enhance our ability to detect AF. Most clinical management decisions in AF patients can be based on validated parameters that encompass type of presentation, clinical factors, electrocardiogram analysis, and cardiac imaging. Despite these advances, patients with AF are still at increased risk for death, stroke, heart failure, and hospitalizations. During the fourth Atrial Fibrillation competence NETwork/European Heart Rhythm Association (AFNET/EHRA) consensus conference, we identified the following opportunities to personalize management of AF in a better manner with a view to improve outcomes by integrating atrial morphology and damage, brain imaging, information on genetic predisposition, systemic or local inflammation, and markers for cardiac strain. Each of these promising avenues requires validation in the context of existing risk factors in patients. More importantly, a new taxonomy of AF may be needed based on the pathophysiological type of AF to allow personalized management of AF to come to full fruition. Continued translational research efforts are needed to personalize management of this prevalent disease in a better manner. All the efforts are expected to improve the management of patients with AF based on personalized therapy. PMID:23981824

  17. Use of event recorders and loop recorders in clinical practice: results of the European Heart Rhythm Association Survey.

    PubMed

    Sciaraffia, Elena; Chen, Jian; Hocini, Meleze; Larsen, Torben Bierregaard; Potpara, Tatjana; Blomström-Lundqvist, Carina

    2014-09-01

    Several kinds of electrocardiogram monitoring systems are now available in the clinical practice. The aim of this European Heart Rhythm Association (EHRA) survey was to assess the use of different monitoring techniques in the evaluation of patients with unexplained syncope, palpitations, and in those with established diagnosis of atrial fibrillation. Forty-five centres in Europe answered the questionnaire and the majority (78%) were university hospitals. The answers showed a discrepancy between the recommended use of implantable loop recorders (ILRs) in patients with unexplained syncope and the use of this device in clinical practice. In most of the cases only a minority of patients (<20%) seemed to actually receive an ILR as a part of the diagnostic process in accordance to the current guidelines. Holter monitoring systems and external loop recorders seemed to be the preferred monitoring techniques both in patients with recurrent palpitations and in those with established diagnosis of atrial fibrillation. PMID:25172620

  18. How are arrhythmias detected by implanted cardiac devices managed in Europe? Results of the European Heart Rhythm Association Survey.

    PubMed

    Todd, Derick; Hernandez-Madrid, Antonio; Proclemer, Alessandro; Bongiorni, Maria Grazia; Estner, Heidi; Blomström-Lundqvist, Carina

    2015-09-01

    The management of arrhythmias detected by implantable cardiac devices can be challenging. There are no formal international guidelines to inform decision-making. The purpose of this European Heart Rhythm Association (EHRA) survey was to assess the management of various clinical scenarios among members of the EHRA electrophysiology research network. There were 49 responses to the questionnaire. The survey responses were mainly (81%) from medium-high volume device implanting centres, performing more than 200 total device implants per year. Clinical scenarios were described focusing on four key areas: the implantation of pacemakers for bradyarrhythmia detected on an implantable loop recorder (ILR), the management of patients with ventricular arrhythmia detected by an ILR or pacemaker, the management of atrial fibrillation in patients with pacemakers and cardiac resynchronization therapy devices and the management of ventricular tachycardia in patients with implantable cardioverter-defibrillators. PMID:26443791

  19. Current implantable cardioverter-defibrillator programming in Europe: the results of the European Heart Rhythm Association survey.

    PubMed

    Proclemer, Alessandro; Grazia Bongiorni, Maria; Etsner, Heidi; Todd, Derick; Sciaraffia, Elena; Blomström-Lundqvist, Carina

    2014-06-01

    The purpose of this European Heart Rhythm Association (EHRA) survey was to examine the current practice on the choice of implantable cardioverter-defibrillator (ICD) type, use of defibrillation testing, and ICD programming for detection and therapy of ventricular arrhythmias. In accordance with recent guidelines and the results of observational studies, the majority of EHRA research network centres reported a high utilization rate of dual-chamber ICDs in the presence of symptomatic and asymptomatic sinus node dysfunction, biventricular ICD in high-degree atrioventricular block and QRS duration <120 ms, and a limited use of defibrillation testing either in primary and secondary prevention settings. Activation of the long ventricular tachycardia (VT) detection window, slow VT zone, antitachycardia pacing before shock for slow and fast VT, and atrial tachyarrhythmia discrimination were considered useful in ICD programming for the majority of patients. PMID:24864305

  20. Management of atrial fibrillation in patients with chronic kidney disease in Europe Results of the European Heart Rhythm Association Survey.

    PubMed

    Potpara, Tatjana S; Lenarczyk, Radoslaw; Larsen, Torben B; Deharo, Jean-Claude; Chen, Jian; Dagres, Nikolaos

    2015-12-01

    The purpose of this European Heart Rhythm (EHRA) Scientific Initiatives Committee EP Wire Survey was to assess 'real-world' practice in the management of patients with atrial fibrillation (AF) and chronic kidney disease (CKD) in the European Eelectrophysiology centres. Of 41 responding centres, 39 (95.1%) and 37 (90.2%) routinely evaluated renal function in AF patients at first presentation and during follow-up, respectively, but 13 centres (31.7%) re-assessed advanced CKD only at ≥1-year intervals. While the use of oral anticoagulants (OACs) in mild-to-moderate CKD patients was mostly guided by individual patient stroke risk, 31% of the centres used no therapy, or aspirin or the left appendage occlusion in patients with advanced CKD and HAS-BLED ≥ 3. Vitamin K antagonists (VKAs) were preferred in patients with severe CKD or under renal replacement therapy (RRT), any non-VKA in patients with mild CKD, and apixaban in patients with moderate CKD. Rhythm control was preferred in patients with mild-to-moderate CKD (48.7% of centres), and rate control in patients with severe CKD (51.2% of centres). In 20 centres (48.8%), AF ablation was not performed in advanced CKD patients. Most centres performed AF ablation on OAC, but heparin bridging was still used in >10% of centres. Our survey has shown that the importance of renal function monitoring in AF patients is well recognized in clinical practice. In patients with mild-to-moderate CKD, AF is mostly managed according to the guideline recommendations, but more data are needed to guide the management of AF in patients with severe CKD or RRT. PMID:26733617

  1. Substances and Heart Rhythm Disorders

    MedlinePlus

    ... in others. These rhythm problems are rarely serious. Substance Abuse: Drugs and Inhalants Abusing legal or illegal drugs ... people, alcohol can cause heart rhythm disturbances. Alcohol abuse is a major risk factor for High ... herbs and other substances used in over-the-counter remedies are believed ...

  2. Recognizing an Irregular Heart Rhythm

    MedlinePlus

    ... a workout, consider checking your rhythm as well. Atrial fibrillation, also referred to as AF, is a common ... upper chambers, or atria, of the heart. “While atrial fibrillation is not common among young people, it can ...

  3. Left atrial appendage closure-indications, techniques, and outcomes: results of the European Heart Rhythm Association Survey.

    PubMed

    Pison, Laurent; Potpara, Tatjana S; Chen, Jian; Larsen, Torben B; Bongiorni, Maria Grazia; Blomström-Lundqvist, Carina

    2015-04-01

    The purpose of this EP Wire was to assess the indications, techniques, and outcomes of left atrial appendage occlusion (LAAO) in Europe. Thirty-three European centres, all members of the European Heart Rhythm Association electrophysiology (EP) research network, responded to this survey by completing the questionnaire. The major indication for LAAO (94%) was the prevention of stroke in patients at high thrombo-embolic risk (CHA2DS2-VASc ≥ 2) and contraindications to oral anticoagulants (OACs). Twenty-one (64%) of the responding centres perform LAAO in their own institution and 80% implanted 30 or less LAAO devices in 2014. Two-dimensional transoesophageal echocardiography was the preferred imaging technique to visualize LAA before, during, and after LAAO in 79, 58, and 62% of the participating centres, respectively. Following LAAO, 49% of the centres prescribe vitamin K antagonists or novel OACs. Twenty-five per cent of the centres combine LAAO with pulmonary vein isolation. The periprocedural complications included death (range, 0-3%), ischaemic or haemorrhagic stroke (0-25%), tamponade (0-25%), and device embolization (0-20%). In conclusion, this EP Wire has demonstrated that LAAO is most commonly employed in patients at high thrombo-embolic risk in whom OAC is contraindicated. The technique is not yet very widespread and the complication rates remain significant. PMID:25833883

  4. Preferred tools and techniques for implantation of cardiac electronic devices in Europe: results of the European Heart Rhythm Association survey.

    PubMed

    Bongiorni, Maria Grazia; Proclemer, Alessandro; Dobreanu, Dan; Marinskis, Germanas; Pison, Laurent; Blomstrom-Lundqvist, Carina

    2013-11-01

    The aim of this European Heart Rhythm Association (EHRA) survey was to assess clinical practice in relation to the tools and techniques used for cardiac implantable electronic devices procedures in the European countries. Responses to the questionnaire were received from 62 members of the EHRA research network. The survey involved high-, medium-, and low-volume implanting centres, performing, respectively, more than 200, 100-199 and under 100 implants per year. The following topics were explored: the side approach for implantation, surgical techniques for pocket incision, first venous access for lead implantation, preference of lead fixation, preferred coil number for implantable cardioverter-defibrillator (ICD) leads, right ventricular pacing site, generator placement site, subcutaneous ICD implantation, specific tools and techniques for cardiac resynchronization therapy (CRT), lead implantation sequence in CRT, coronary sinus cannulation technique, target site for left ventricular lead placement, strategy in left ventricular lead implant failure, mean CRT implantation time, optimization of the atrioventricular (AV) and ventriculo-ventricular intervals, CRT implants in patients with permanent atrial fibrillation, AV node ablation in patients with permanent AF. This panoramic view allows us to find out the operator preferences regarding the techniques and tools for device implantation in Europe. The results showed different practices in all the fields we investigated, nevertheless the survey also outlines a good adherence to the common standards and recommendations. PMID:24170423

  5. Management of malfunctioning and recalled pacemaker and defibrillator leads: results of the European Heart Rhythm Association survey.

    PubMed

    Grazia Bongiorni, Maria; Dagres, Nikolaos; Estner, Heidi; Pison, Laurent; Todd, Derick; Blomstrom-Lundqvist, Carina

    2014-11-01

    The aim of this survey was to describe the different strategies regarding the management of malfunctioning and recalled pacemaker and defibrillator leads across Europe. A questionnaire has been designed to assess the current practice and physician's approach to the management of leads which are faulty, unnecessary, and/or recalled. Responses to the questionnaire were received from 34 hospitals-members of the European Heart Rhythm Association (EHRA) electrophysiology (EP) research network. The survey involved both very high and low volume implanting centres, with 85% of the responding centres performing lead extraction. The survey provides a panoramic view of operator's decision making in the field of malfunctioning, recalled, and redundant leads and outlines a common point of view on lead abandonment and factors influencing the decision about lead extraction. The main factors strongly influencing the decision making were patient's age (59%), the presence of the damaged leads (44%), and the lead dwelling time (44%). Regarding the lead abandonment, the main concern (61%) was the potential greater difficulty associated with lead extraction in the future. High volume extracting centres showed a greater propensity to removing the malfunctioning or recalled leads compared with low volume or non-extracting centres. This EP Wire survey gives a snapshot of the operators' approaches and options regarding redundant, malfunctioning, and recalled lead management and may form the basis for future prospective research on this topic. PMID:25344962

  6. The use of wearable cardioverter-defibrillators in Europe: results of the European Heart Rhythm Association survey.

    PubMed

    Lenarczyk, Radosław; Potpara, Tatjana S; Haugaa, Kristina H; Hernández-Madrid, Antonio; Sciaraffia, Elena; Dagres, Nikolaos

    2016-01-01

    The aim of this European Heart Rhythm Association (EHRA) survey was to collect data on the use of wearable cardioverter-defibrillators (WCDs) among members of the EHRA electrophysiology research network. Of the 50 responding centres, 23 (47%) reported WCD use. Devices were fully reimbursed in 17 (43.6%) of 39 respondents, and partially reimbursed in 3 centres (7.7%). Eleven out of 20 centres (55%) reported acceptable patients' compliance (WCD worn for >90% of time). The most common indications for WCD (8 out of 10 centres; 80%) were covering the period until re-implantation of ICD explanted due to infection, in patients with left ventricular impairment due to myocarditis or recent myocardial infarction and those awaiting heart transplantation. Patient life expectancy of <12 months and poor compliance were the most commonly reported contraindications for WCD (24 of 46 centres, 52.2%). The major problems encountered by physicians managing patients with WCD were costs (8 of 18 centres, 44.4%), non-compliance, and incorrect use of WCD. Four of 17 centres (23.5%) reported inappropriate WCD activations in <5% of patients. The first shock success rate in terminating ventricular arrhythmias was 95-100% in 6 of 15 centres (40%), 85-95% in 4 (26.7%), 75-85% in 2 (13.3%), and <75% in 3 centres (20%). The survey has shown that the use of WCD in Europe is still restricted and depends on reimbursement. Patients' compliance remains low. Heterogeneity of indications for WCD among centres underscores the need for further research and a better definition of indications for WCD in specific patient groups. PMID:26842735

  7. How are arrhythmias managed in the paediatric population in Europe? Results of the European Heart Rhythm survey.

    PubMed

    Hernández-Madrid, Antonio; Hocini, Mélèze; Chen, Jian; Potpara, Tatjana; Pison, Laurent; Blomström-Lundqvist, Carina

    2014-12-01

    The aim of this survey was to provide insight into current practice regarding the management of paediatric arrhythmias in Europe. The survey was based on a questionnaire sent via the Internet to the European Heart Rhythm Association (EHRA) electrophysiology research network centres. The following topics were explored: patient and treatment selection, techniques and equipment, treatment outcomes and complications. The vast majority of paediatric arrhythmias concerns children older than 1 year and patients with grown-up congenital heart disease. In 65% of the hospitals there is a specialized paediatric centre, and the most commonly observed arrhythmias include Wolff-Parkinson-White syndrome and atrioventricular nodal re-entry tachycardias (90.24%). The medical staff performing paediatric catheter ablations in Europe are mainly adult electrophysiology teams (82.05% of the centres). Radiofrequency is the preferred energy source used for paediatric arrhythmia ablation. Catheter ablation is only chosen if two or more antiarrhythmic drugs have failed (94.59% of the centres). The majority of the centres use flecainide (37.8%) or atenolol (32.4%) as their first choice drug for prevention of recurrent supraventricular arrhythmias. While none of the centres performed catheter ablation in asymptomatic infants with pre-excitation, 29.7% recommend ablation in asymptomatic children and adolescents. The preferred choice for pacemaker leads in infants less than 1 year old is implantation of epicardial leads in 97.3% of the centres, which continues to be the routine even in patients between 1 and 5 years of age as reported by 75.68% of the hospitals. Almost all centres (94.59%) report equally small number of complications of catheter ablation in children (aged 1-14 years) as observed in adults. PMID:25417228

  8. Replacement of implantable cardioverter defibrillators and cardiac resynchronization therapy devices: results of the European Heart Rhythm Association survey.

    PubMed

    Tilz, Roland; Boveda, Serge; Deharo, Jean-Claude; Dobreanu, Dan; Haugaa, Kristina H; Dagres, Nikolaos

    2016-06-01

    The aim of this EP Wire was to assess the management, indications, and techniques for implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy (CRT) device replacement in Europe. A total of 24 centres in 14 European countries completed the questionnaire. All centres were members of the European Heart Rhythm Association Electrophysiology Research Network. Replacement procedures were performed by electrophysiologists in 52% of the centres, by cardiologists in 33%, and both in the remaining centres. In the majority of centres, the procedures were performed during a short hospitalization (<2 days; 61.2%), or on an outpatient basis (28%). The overwhelming majority of centres reported that they replaced ICDs at the end of battery life. Only in a small subset (<10%) of patients with ICD for primary prevention and without ventricular tachycardia (VT) since implantation, ICD was not replaced. In inherited primary arrhythmia syndromes, 80% of the centres always replaced the ICD at the end of battery life. After VT ablation, only few centres (9%) explanted or downgraded the device that was previously implanted for secondary prevention, but only in those patients without new VT episodes. Patient's life expectancy <1 year was the most commonly reported reason (61%) to downgrade from a CRT-D to a CRT-P device. While warfarin therapy was continued in 47% of the centres, non-vitamin K oral anticoagulants were discontinued without bridging 24 h prior to replacement procedures in 60%. Finally, in 65% of the centres, VT induction and shock testing during ICD and CRT-D replacement were performed only in the case of leads with a warning or with borderline measurements. This survey provides a snapshot of the perioperative management, indications, and techniques of ICD and CRT device replacement in Europe. It demonstrates some variations between participating centres, probably related to local policies and to the heterogeneity of the ICD population. PMID

  9. Non-vitamin K oral anticoagulants in patients with atrial fibrillation after cardiac surgery: the results of the European Heart Rhythm Association Survey.

    PubMed

    Vranckx, Pascal; Potpara, Tatjana; Dagres, Nikolaos; Heidbuchel, Hein

    2016-07-01

    The purpose of this European Heart Rhythm Association survey was to assess the current practice concerning the use of oral anticoagulation in patients with post-operative atrial fibrillation (pre-existing or new-onset). The survey highlights the considerable heterogeneity of the type of anticoagulation, with 25% of the centres never using the non-vitamin K antagonist oral anticoagulants (NOACs) in this setting, as well the timing of oral anticoagulation initiation, the use and dosing of low-molecular-weight heparins, and the duration of anticoagulation when sinus rhythm is restored. One-third of the centres stated that they perceived that the risk of major pericardial bleeding requiring pericardiocentesis was higher when NOACs were used compared with vitamin K antagonists. Overall, the responding centres estimated the incidence of major pericardial haemorrhage to be 2.4%. More data are needed to inform practice guidelines in this field. PMID:27358360

  10. The role of the Arrhythmia Team, an integrated, multidisciplinary approach to treatment of patients with cardiac arrhythmias: results of the European Heart Rhythm Association survey.

    PubMed

    Fumagalli, Stefano; Chen, Jian; Dobreanu, Dan; Madrid, Antonio Hernandez; Tilz, Roland; Dagres, Nikolaos

    2016-04-01

    Management of patients with cardiac arrhythmias is increasingly complex because of continuous technological advance and multifaceted clinical conditions associated with ageing of the population, the presence of co-morbidities and the need for polypharmacy. The aim of this European Heart Rhythm Association Scientific Initiatives Committee survey was to provide an insight into the role of the Arrhythmia Team, an integrated, multidisciplinary approach to management of patients with cardiac arrhythmias. Forty-eight centres from 18 European countries replied to the Web-based questionnaire. The presence of an Arrhythmia Team was reported by 44% of the respondents, whereas 17% were not familiar with this term. Apart from the electrophysiologist, health professionals who should belong to such teams, according to the majority of the respondents, include a clinical cardiologist, a nurse, a cardiac surgeon, a heart failure specialist, a geneticist, and a geriatrician. Its main activity should be dedicated to the management of patients with complex clinical conditions or refractory or inherited forms of arrhythmias. When present, the Arrhythmia Team was considered helpful by 95% of respondents; the majority of centres (79%) agreed that it should be implemented. The Arrhythmia Team seems to be connected to important expectations in the management of cardiac arrhythmias. The efficacy of such an integrated and multidisciplinary approach should be encouraged and tested in clinical practice. PMID:27174994

  11. A roadmap to improve the quality of atrial fibrillation management: proceedings from the fifth Atrial Fibrillation Network/European Heart Rhythm Association consensus conference.

    PubMed

    Kirchhof, Paulus; Breithardt, Günter; Bax, Jeroen; Benninger, Gerlinde; Blomstrom-Lundqvist, Carina; Boriani, Giuseppe; Brandes, Axel; Brown, Helen; Brueckmann, Martina; Calkins, Hugh; Calvert, Melanie; Christoffels, Vincent; Crijns, Harry; Dobrev, Dobromir; Ellinor, Patrick; Fabritz, Larissa; Fetsch, Thomas; Freedman, S Ben; Gerth, Andrea; Goette, Andreas; Guasch, Eduard; Hack, Guido; Haegeli, Laurent; Hatem, Stephane; Haeusler, Karl Georg; Heidbüchel, Hein; Heinrich-Nols, Jutta; Hidden-Lucet, Francoise; Hindricks, Gerd; Juul-Möller, Steen; Kääb, Stefan; Kappenberger, Lukas; Kespohl, Stefanie; Kotecha, Dipak; Lane, Deirdre A; Leute, Angelika; Lewalter, Thorsten; Meyer, Ralf; Mont, Lluis; Münzel, Felix; Nabauer, Michael; Nielsen, Jens C; Oeff, Michael; Oldgren, Jonas; Oto, Ali; Piccini, Jonathan P; Pilmeyer, Art; Potpara, Tatjana; Ravens, Ursula; Reinecke, Holger; Rostock, Thomas; Rustige, Joerg; Savelieva, Irene; Schnabel, Renate; Schotten, Ulrich; Schwichtenberg, Lars; Sinner, Moritz F; Steinbeck, Gerhard; Stoll, Monika; Tavazzi, Luigi; Themistoclakis, Sakis; Tse, Hung Fat; Van Gelder, Isabelle C; Vardas, Panagiotis E; Varpula, Timo; Vincent, Alphons; Werring, David; Willems, Stephan; Ziegler, André; Lip, Gregory Y H; Camm, A John

    2016-01-01

    At least 30 million people worldwide carry a diagnosis of atrial fibrillation (AF), and many more suffer from undiagnosed, subclinical, or 'silent' AF. Atrial fibrillation-related cardiovascular mortality and morbidity, including cardiovascular deaths, heart failure, stroke, and hospitalizations, remain unacceptably high, even when evidence-based therapies such as anticoagulation and rate control are used. Furthermore, it is still necessary to define how best to prevent AF, largely due to a lack of clinical measures that would allow identification of treatable causes of AF in any given patient. Hence, there are important unmet clinical and research needs in the evaluation and management of AF patients. The ensuing needs and opportunities for improving the quality of AF care were discussed during the fifth Atrial Fibrillation Network/European Heart Rhythm Association consensus conference in Nice, France, on 22 and 23 January 2015. Here, we report the outcome of this conference, with a focus on (i) learning from our 'neighbours' to improve AF care, (ii) patient-centred approaches to AF management, (iii) structured care of AF patients, (iv) improving the quality of AF treatment, and (v) personalization of AF management. This report ends with a list of priorities for research in AF patients. PMID:26481149

  12. Preference for oral anticoagulation therapy for patients with atrial fibrillation in Europe in different clinical situations: results of the European Heart Rhythm Association Survey.

    PubMed

    Larsen, Torben Bjerregaard; Potpara, Tatjana; Dagres, Nikolaos; Proclemer, Alessandro; Sciarrafia, Elena; Blomström-Lundqvist, Carina

    2015-05-01

    The purpose of this European Heart Rhythm Association Survey was to assess the clinical practice in relation to the use of oral anticoagulation therapy for patients with atrial fibrillation (AF) in Europe. Of special interest were patients undergoing percutaneous coronary intervention (PCI), cardioversion procedures, catheter ablation, surgery, and those suffering from anticoagulation-related bleeding. Of 38 responding centres, non-vitamin K antagonist oral anticoagulants (NOACs) were used for stroke prophylaxis and were preferred (33.3%) or considered equal (48.5%) to vitamin K antagonists (VKAs). Only 3% did not use NOACs at all. There were some practice differences regarding the use of NOACs in combination with dual antiplatelet therapy in AF patients undergoing PCI, and only 12% preferred using NOACs in this setting. Bare metal stents were preferred rather than drug-eluting stents in AF patients at high bleeding risk. There were clear practice differences between centres regarding the use of triple therapy. Most of the major bleeding events would be handled using symptomatic and supportive measures (e.g. mechanical compression, fluid replacement, blood transfusion, prothrombin complex concentrate, or recombinant Factor VIIa). More than 80% of the centres offer either VKA or NOAC for at least 3 weeks before and after cardioversion and 70% offer either VKA or NOAC before and after AF catheter ablation. Patients treated with an NOAC were routinely re-assed in most centres. PMID:25926476

  13. The European Heart Rhythm Association Practical Guide on the Use of New Oral Anticoagulants in Patients with Non-valvular Atrial Fibrillation – A Brief Summary

    PubMed Central

    Kirchhof, Paulus

    2013-01-01

    New oral anticoagulants (NOACs) are an alternative to vitamin K antagonists (VKAs) in the prevention of stroke in patients with non-valvular atrial fibrillation (AF). The European Heart Rhythm Association (EHRA) has produced a practical guide to detail the use of NOACs in clinical practice. The guide includes a practical start-up and follow-up scheme, emphasising the importance of strict adherence to the regimen – the anticoagulant effect drops rapidly after 12–24 hours. There is also guidance on how to measure the anticoagulant effect of NOACs, switching between anticoagulant regimes and dealing with dosing errors. Physicians will have to consider the pharmacokinetic effect of drugs and co-morbidities when prescribing NOACs – plasma levels of NOACs may be affected by P-glycoprotein (P-gp) substrates, as well as cytochrome P450 (CYP3A4) inducers or inhibitors. In patients with chronic kidney disease, reduced doses of NOACs may be indicated. Guidance is also given on the management of bleeding complications, and the cessation and reinitiation of NOACs in patients undergoing surgical interventions. Finally, the use of NOACs in specific clinical situations is considered; these include patients with AF and coronary artery disease (CAD), patients presenting with acute stroke while taking NOACs and patients with cancer. PMID:26835051

  14. How are patients with atrial fibrillation approached and informed about their risk profile and available therapies in Europe? Results of the European Heart Rhythm Association Survey.

    PubMed

    Potpara, Tatjana S; Pison, Laurent; Larsen, Torben B; Estner, Heidi; Madrid, Antonio; Blomström-Lundqvist, Carina

    2015-03-01

    This European Heart Rhythm (EHRA) Scientific Initiatives Committee EP Wire Survey aimed at exploring the common practices in approaching patients with atrial fibrillation (AF) and informing them about their risk profiles and available therapies in Europe. In the majority of 53 responding centres, patients were seen by cardiologists (86.8%) or arrhythmologists (64.2%). First- and follow-up visits most commonly lasted 21-30 and 11-20 min (41.5 and 69.8% of centres, respectively). In most centres (80.2%) stroke and bleeding risk had the highest priority for discussion with AF patients; 50.9% of centres had a structured patient education programme for stroke prevention. Individual patient stroke risk was assessed at every visit in 69.2% of the centres; 46.1% of centres had a hospital-based anticoagulation clinic. Information about non-vitamin K oral anticoagulants (NOACs) was communicated to all AF patients eligible for oral anticoagulation (38.5% of centres) or to warfarin-naive/unstable patients (42.3%). Only two centres (3.8%) had a structured NOAC adherence follow-up programme; in eight centres (15.4%) patients were requested to sign the statement they have been informed about the risks of non-adherence to NOAC therapy, and three centres (5.8%) had a patient education programme. Patient preferences were of the highest relevance regarding oral anticoagulation and AF ablation (64.7 and 49.0% of centres, respectively). This EP Wire Survey shows that in Europe considerable amount of time and resources are used in daily clinical practice to inform AF patients about their risk profile and available therapies. However, a diversity of strategies used across the European hospitals was noted, and further research is needed to better define optimal strategies for informing AF patients about their risk profile and treatment options. PMID:25722478

  15. How are European patients at risk of malignant arrhythmias or sudden cardiac death identified and informed about their risk profile: results of the European Heart Rhythm Association survey.

    PubMed

    Proclemer, Alessandro; Bongiorni, Maria Grazia; Dagres, Nikolaos; Sciaraffia, Elena; Todd, Derick; Blomstrom-Lundqvist, Carina

    2015-06-01

    The purpose of this EP wire is to examine clinical practice in the field of screening of patients of risk of ventricular arrhythmias and/or sudden cardiac death (SCD) in European countries. A systematic screening programme existed in the majority of centres and was organized by a multidisciplinary dedicated team or by an activity programme of implantable cardioverter-defibrillator (ICD) or heart failure clinics. In particular, high-risk subgroups of patients with ischaemic and non-ischaemic cardiomyopathy ICD implantation are considered strongly indicated within 90 days of myocardial revascularization or initial diagnosis. Cardiac magnetic resonance imaging appears as an important tool to better characterize the left ventricular arrhythmogenic substrate in patients at risk of SCD. PMID:26023178

  16. Comprehensive risk reduction in patients with atrial fibrillation: emerging diagnostic and therapeutic options--a report from the 3rd Atrial Fibrillation Competence NETwork/European Heart Rhythm Association consensus conference.

    PubMed

    Kirchhof, Paulus; Lip, Gregory Y H; Van Gelder, Isabelle C; Bax, Jeroen; Hylek, Elaine; Kaab, Stefan; Schotten, Ulrich; Wegscheider, Karl; Boriani, Giuseppe; Brandes, Axel; Ezekowitz, Michael; Diener, Hans; Haegeli, Laurent; Heidbuchel, Hein; Lane, Deirdre; Mont, Luis; Willems, Stephan; Dorian, Paul; Aunes-Jansson, Maria; Blomstrom-Lundqvist, Carina; Borentain, Maria; Breitenstein, Stefanie; Brueckmann, Martina; Cater, Nilo; Clemens, Andreas; Dobrev, Dobromir; Dubner, Sergio; Edvardsson, Nils G; Friberg, Leif; Goette, Andreas; Gulizia, Michele; Hatala, Robert; Horwood, Jenny; Szumowski, Lukas; Kappenberger, Lukas; Kautzner, Josef; Leute, Angelika; Lobban, Trudie; Meyer, Ralf; Millerhagen, Jay; Morgan, John; Muenzel, Felix; Nabauer, Michael; Baertels, Christoph; Oeff, Michael; Paar, Dieter; Polifka, Juergen; Ravens, Ursula; Rosin, Ludger; Stegink, W; Steinbeck, Gerhard; Vardas, Panos; Vincent, Alphons; Walter, Maureen; Breithardt, Günter; Camm, A John

    2012-01-01

    While management of atrial fibrillation (AF) patients is improved by guideline-conform application of anticoagulant therapy, rate control, rhythm control, and therapy of accompanying heart disease, the morbidity and mortality associated with AF remain unacceptably high. This paper describes the proceedings of the 3rd Atrial Fibrillation NETwork (AFNET)/European Heart Rhythm Association (EHRA) consensus conference that convened over 60 scientists and representatives from industry to jointly discuss emerging therapeutic and diagnostic improvements to achieve better management of AF patients. The paper covers four chapters: (i) risk factors and risk markers for AF; (ii) pathophysiological classification of AF; (iii) relevance of monitored AF duration for AF-related outcomes; and (iv) perspectives and needs for implementing better antithrombotic therapy. Relevant published literature for each section is covered, and suggestions for the improvement of management in each area are put forward. Combined, the propositions formulate a perspective to implement comprehensive management in AF. PMID:21791573

  17. Comprehensive risk reduction in patients with atrial fibrillation: emerging diagnostic and therapeutic options—a report from the 3rd Atrial Fibrillation Competence NETwork/European Heart Rhythm Association consensus conference

    PubMed Central

    Kirchhof, Paulus; Lip, Gregory Y.H.; Van Gelder, Isabelle C.; Bax, Jeroen; Hylek, Elaine; Kaab, Stefan; Schotten, Ulrich; Wegscheider, Karl; Boriani, Giuseppe; Brandes, Axel; Ezekowitz, Michael; Diener, Hans; Haegeli, Laurent; Heidbuchel, Hein; Lane, Deirdre; Mont, Luis; Willems, Stephan; Dorian, Paul; Aunes-Jansson, Maria; Blomstrom-Lundqvist, Carina; Borentain, Maria; Breitenstein, Stefanie; Brueckmann, Martina; Cater, Nilo; Clemens, Andreas; Dobrev, Dobromir; Dubner, Sergio; Edvardsson, Nils G.; Friberg, Leif; Goette, Andreas; Gulizia, Michele; Hatala, Robert; Horwood, Jenny; Szumowski, Lukas; Kappenberger, Lukas; Kautzner, Josef; Leute, Angelika; Lobban, Trudie; Meyer, Ralf; Millerhagen, Jay; Morgan, John; Muenzel, Felix; Nabauer, Michael; Baertels, Christoph; Oeff, Michael; Paar, Dieter; Polifka, Juergen; Ravens, Ursula; Rosin, Ludger; Stegink, W.; Steinbeck, Gerhard; Vardas, Panos; Vincent, Alphons; Walter, Maureen; Breithardt, Günter; Camm, A. John

    2012-01-01

    While management of atrial fibrillation (AF) patients is improved by guideline-conform application of anticoagulant therapy, rate control, rhythm control, and therapy of accompanying heart disease, the morbidity and mortality associated with AF remain unacceptably high. This paper describes the proceedings of the 3rd Atrial Fibrillation NETwork (AFNET)/European Heart Rhythm Association (EHRA) consensus conference that convened over 60 scientists and representatives from industry to jointly discuss emerging therapeutic and diagnostic improvements to achieve better management of AF patients. The paper covers four chapters: (i) risk factors and risk markers for AF; (ii) pathophysiological classification of AF; (iii) relevance of monitored AF duration for AF-related outcomes; and (iv) perspectives and needs for implementing better antithrombotic therapy. Relevant published literature for each section is covered, and suggestions for the improvement of management in each area are put forward. Combined, the propositions formulate a perspective to implement comprehensive management in AF. PMID:21791573

  18. Advances in heart rate variability signal analysis: joint position statement by the e-Cardiology ESC Working Group and the European Heart Rhythm Association co-endorsed by the Asia Pacific Heart Rhythm Society.

    PubMed

    Sassi, Roberto; Cerutti, Sergio; Lombardi, Federico; Malik, Marek; Huikuri, Heikki V; Peng, Chung-Kang; Schmidt, Georg; Yamamoto, Yoshiharu

    2015-09-01

    Following the publication of the Task Force document on heart rate variability (HRV) in 1996, a number of articles have been published to describe new HRV methodologies and their application in different physiological and clinical studies. This document presents a critical review of the new methods. A particular attention has been paid to methodologies that have not been reported in the 1996 standardization document but have been more recently tested in sufficiently sized populations. The following methods were considered: Long-range correlation and fractal analysis; Short-term complexity; Entropy and regularity; and Nonlinear dynamical systems and chaotic behaviour. For each of these methods, technical aspects, clinical achievements, and suggestions for clinical application were reviewed. While the novel approaches have contributed in the technical understanding of the signal character of HRV, their success in developing new clinical tools, such as those for the identification of high-risk patients, has been rather limited. Available results obtained in selected populations of patients by specialized laboratories are nevertheless of interest but new prospective studies are needed. The investigation of new parameters, descriptive of the complex regulation mechanisms of heart rate, has to be encouraged because not all information in the HRV signal is captured by traditional methods. The new technologies thus could provide after proper validation, additional physiological, and clinical meaning. Multidisciplinary dialogue and specialized courses in the combination of clinical cardiology and complex signal processing methods seem warranted for further advances in studies of cardiac oscillations and in the understanding normal and abnormal cardiac control processes. PMID:26177817

  19. Heart rhythm during permanent cardiac pacing.

    PubMed Central

    Edhag, O; Rosenqvist, M

    1979-01-01

    Heart rhythm was analysed with regard to spontaneous or pacemaker-induced heart activity, in a consecutive series of 282 patients paced for at least 1 year. The mean duration of pacing was 59 (13 to 180) months. The mean age of the patients was 76 (39 to 93) years. Spontaneous heart activity at all routine examinations was found in 33 (12%) of the patients. Pacemaker-induced rhythm only was recorded in 42 per cent of the patients whereas the remaining 46 per cent had varying electrocardiographic patterns. Of the patients with spontaneous rhythm at each visit, 10 had had complete heart block before pacing. Regular sinus activity was recorded at every routine examination in 74 per cent of the patients paced for reasons other than the sick sinus syndrome. This indicated that a substantial number of paced patients might be candidates for atrial triggered pacing. Patients treated with digitalis more often had asystole at the time of replacement of the pacemaker (32%) than those not so treated (19). This suggests an increased risk of sudden death in paced patients on digitalis if the pacemaker fails. PMID:486279

  20. Bleeding risk assessment and management in atrial fibrillation patients. Executive Summary of a Position Document from the European Heart Rhythm Association [EHRA], endorsed by the European Society of Cardiology [ESC] Working Group on Thrombosis.

    PubMed

    Lip, Gregory Y H; Andreotti, Felicita; Fauchier, Laurent; Huber, Kurt; Hylek, Elaine; Knight, Eve; Lane, Deirdre; Levi, Marcel; Marín, Francisco; Palareti, Gualtiero; Kirchhof, Paulus

    2011-12-01

    In this executive summary of a Consensus Document from the European Heart Rhythm Association, endorsed by the European Society of Cardiology Working Group on Thrombosis, we comprehensively review the published evidence and propose a consensus on bleeding risk assessments in atrial fibrillation (AF) patients. The main aim of the document was to summarise 'best practice' in dealing with bleeding risk in AF patients when approaching antithrombotic therapy, by addressing the epidemiology and size of the problem, and review established bleeding risk factors. We also summarise definitions of bleeding in the published literature. Patient values and preferences balancing the risk of bleeding against thromboembolism as well as the prognostic implications of bleeding are reviewed. We also provide an overview of published bleeding risk stratification and bleeding risk schema. Brief discussion of special situations (e.g. periablation, peri-devices such as implantable cardioverter defibrillators [ICD] or pacemakers, presentation with acute coronary syndromes and/or requiring percutanous coronary interventions/stents and bridging therapy) is made, as well as a discussion of the prevention of bleeds and managing bleeding complications. Finally, this document puts forwards consensus statements that may help to define evidence gaps and assist in everyday clinical practice. PMID:22048796

  1. Death of Loved One May Trigger Heart Rhythm Trouble

    MedlinePlus

    ... nlm.nih.gov/medlineplus/news/fullstory_158176.html Death of Loved One May Trigger Heart Rhythm Trouble ... likely to develop an irregular heartbeat following the death of their spouse or life partner, particularly if ...

  2. Implementation and reimbursement of remote monitoring for cardiac implantable electronic devices in Europe: a survey from the health economics committee of the European Heart Rhythm Association.

    PubMed

    Mairesse, Georges H; Braunschweig, Frieder; Klersy, Katherine; Cowie, Martin R; Leyva, Francisco

    2015-05-01

    Remote monitoring (RM) of cardiac implantable electronic devices (CIEDs) permits early detection of arrhythmias, device, and lead failure and may also be useful in risk-predicting patient-related outcomes. Financial benefits for patients and healthcare organizations have also been shown. We sought to assess the implementation and funding of RM of CIEDs, including conventional pacemakers (PMs), implantable cardioverter defibrillators (ICDs), and cardiac resynchronization therapy (CRT) devices in Europe. Electronic survey from 43 centres in 15 European countries. In the study sample, RM was available in 22% of PM patients, 74% of ICD patients, and 69% of CRT patients. The most significant perceived benefits were the early detection of atrial arrhythmias in pacemaker patients, lead failure in ICD patients, and worsening heart failure in CRT patients. Remote monitoring was reported to lead a reduction of in-office follow-ups for all devices. The most important reported barrier to the implementation of RM for all CIEDs was lack of reimbursement (80% of centres). Physicians regard RM of CIEDs as a clinically useful technology that affords significant benefits for patients and healthcare organizations. Remote monitoring, however, is perceived as increasing workload. Reimbursement for RM is generally perceived as a major barrier to implementation. PMID:25713012

  3. Role of diabetes in heart rhythm disorders

    PubMed Central

    Koektuerk, Buelent; Aksoy, Murat; Horlitz, Marc; Bozdag-Turan, Ilkay; Turan, Ramazan Goekmen

    2016-01-01

    The incidence of diabetes mellitus (DM) is increasing rapidly. DM is the leading cause of cardiovascular diseases, which can lead to varied cardiovascular complications by aggravated atherosclerosis in large arteries and coronary atherosclerosis, thereby grows the risk for macro and microangiopathy such as myocardial infarction, stroke, limb loss and retinopathy. Moreover diabetes is one of the strongest and independent risk factor for cardiovascular morbidity and mortality, which is associated frequently with rhythm disorders such as atrial fibrillation (AF) and ventricular arrhythmias (VA). The present article provides a concise overview of the association between DM and rhythm disorders such as AF and VA with underlying pathophysiological mechanisms. PMID:26862372

  4. Musical rhythms in heart period dynamics: a cross-cultural and interdisciplinary approach to cardiac rhythms.

    PubMed

    Bettermann, H; Amponsah, D; Cysarz, D; van Leeuwen, P

    1999-11-01

    The purpose of this study was to expand classic heart period analysis methods by techniques from ethnomusicology that explicitly take complex musical rhythm principles into consideration. The methods used are based on the theory of African music, the theory of symbolic dynamics, and combinatorial theory. Heart period tachograms from 192 24-h electrocardiograms of 96 healthy subjects were transformed into binary symbol sequences that were interpretable as elementary rhythmic (percussive) patterns, the time lines in African music. Using a hierarchical rhythm pattern scheme closely related to the Derler Rhythm Classification (from jazz theory), we calculated the predominance and stability of pattern classes. The results show that during sleep certain classes, specific to individuals, occurred in a cyclically recurrent manner and many times more often than expected. Simultaneously, other classes disappeared more or less completely. Moreover, the most frequent classes obviously originate from phase-locking processes in autonomic regulation (e.g., between respiratory and cardiac cycles). In conclusion, the new interdisciplinary method presented here demonstrates that heart period patterns, in particular those occurring during night sleep, can be interpreted as musical rhythms. This method may be of great potential use in music therapy research. PMID:10564129

  5. Reversible heart rhythm complexity impairment in patients with primary aldosteronism

    NASA Astrophysics Data System (ADS)

    Lin, Yen-Hung; Wu, Vin-Cent; Lo, Men-Tzung; Wu, Xue-Ming; Hung, Chi-Sheng; Wu, Kwan-Dun; Lin, Chen; Ho, Yi-Lwun; Stowasser, Michael; Peng, Chung-Kang

    2015-08-01

    Excess aldosterone secretion in patients with primary aldosteronism (PA) impairs their cardiovascular system. Heart rhythm complexity analysis, derived from heart rate variability (HRV), is a powerful tool to quantify the complex regulatory dynamics of human physiology. We prospectively analyzed 20 patients with aldosterone producing adenoma (APA) that underwent adrenalectomy and 25 patients with essential hypertension (EH). The heart rate data were analyzed by conventional HRV and heart rhythm complexity analysis including detrended fluctuation analysis (DFA) and multiscale entropy (MSE). We found APA patients had significantly decreased DFAα2 on DFA analysis and decreased area 1-5, area 6-15, and area 6-20 on MSE analysis (all p < 0.05). Area 1-5, area 6-15, area 6-20 in the MSE study correlated significantly with log-transformed renin activity and log-transformed aldosterone-renin ratio (all p < = 0.01). The conventional HRV parameters were comparable between PA and EH patients. After adrenalectomy, all the altered DFA and MSE parameters improved significantly (all p < 0.05). The conventional HRV parameters did not change. Our result suggested that heart rhythm complexity is impaired in APA patients and this is at least partially reversed by adrenalectomy.

  6. Predictability of normal heart rhythms and deterministic chaos

    NASA Astrophysics Data System (ADS)

    Lefebvre, J. H.; Goodings, D. A.; Kamath, M. V.; Fallen, E. L.

    1993-04-01

    The evidence for deterministic chaos in normal heart rhythms is examined. Electrocardiograms were recorded of 29 subjects falling into four groups—a young healthy group, an older healthy group, and two groups of patients who had recently suffered an acute myocardial infarction. From the measured R-R intervals, a time series of 1000 first differences was constructed for each subject. The correlation integral of Grassberger and Procaccia was calculated for several subjects using these relatively short time series. No evidence was found for the existence of an attractor having a dimension less than about 4. However, a prediction method recently proposed by Sugihara and May and an autoregressive linear predictor both show that there is a measure of short-term predictability in the differenced R-R intervals. Further analysis revealed that the short-term predictability calculated by the Sugihara-May method is not consistent with the null hypothesis of a Gaussian random process. The evidence for a small amount of nonlinear dynamical behavior together with the short-term predictability suggest that there is an element of deterministic chaos in normal heart rhythms, although it is not strong or persistent. Finally, two useful parameters of the predictability curves are identified, namely, the `first step predictability' and the `predictability decay rate,' neither of which appears to be significantly correlated with the standard deviation of the R-R intervals.

  7. Heart rhythm complexity impairment in patients undergoing peritoneal dialysis.

    PubMed

    Lin, Yen-Hung; Lin, Chen; Ho, Yi-Heng; Wu, Vin-Cent; Lo, Men-Tzung; Hung, Kuan-Yu; Liu, Li-Yu Daisy; Lin, Lian-Yu; Huang, Jenq-Wen; Peng, Chung-Kang

    2016-01-01

    Cardiovascular disease is one of the leading causes of death in patients with advanced renal disease. The objective of this study was to investigate impairments in heart rhythm complexity in patients with end-stage renal disease. We prospectively analyzed 65 patients undergoing peritoneal dialysis (PD) without prior cardiovascular disease and 72 individuals with normal renal function as the control group. Heart rhythm analysis including complexity analysis by including detrended fractal analysis (DFA) and multiscale entropy (MSE) were performed. In linear analysis, the PD patients had a significantly lower standard deviation of normal RR intervals (SDRR) and percentage of absolute differences in normal RR intervals greater than 20 ms (pNN20). Of the nonlinear analysis indicators, scale 5, area under the MSE curve for scale 1 to 5 (area 1-5) and 6 to 20 (area 6-20) were significantly lower than those in the control group. In DFA anaylsis, both DFA α1 and DFA α2 were comparable in both groups. In receiver operating characteristic curve analysis, scale 5 had the greatest discriminatory power for two groups. In both net reclassification improvement model and integrated discrimination improvement models, MSE parameters significantly improved the discriminatory power of SDRR, pNN20, and pNN50. In conclusion, PD patients had worse cardiac complexity parameters. MSE parameters are useful to discriminate PD patients from patients with normal renal function. PMID:27324066

  8. Heart rhythm complexity impairment in patients undergoing peritoneal dialysis

    NASA Astrophysics Data System (ADS)

    Lin, Yen-Hung; Lin, Chen; Ho, Yi-Heng; Wu, Vin-Cent; Lo, Men-Tzung; Hung, Kuan-Yu; Liu, Li-Yu Daisy; Lin, Lian-Yu; Huang, Jenq-Wen; Peng, Chung-Kang

    2016-06-01

    Cardiovascular disease is one of the leading causes of death in patients with advanced renal disease. The objective of this study was to investigate impairments in heart rhythm complexity in patients with end-stage renal disease. We prospectively analyzed 65 patients undergoing peritoneal dialysis (PD) without prior cardiovascular disease and 72 individuals with normal renal function as the control group. Heart rhythm analysis including complexity analysis by including detrended fractal analysis (DFA) and multiscale entropy (MSE) were performed. In linear analysis, the PD patients had a significantly lower standard deviation of normal RR intervals (SDRR) and percentage of absolute differences in normal RR intervals greater than 20 ms (pNN20). Of the nonlinear analysis indicators, scale 5, area under the MSE curve for scale 1 to 5 (area 1–5) and 6 to 20 (area 6–20) were significantly lower than those in the control group. In DFA anaylsis, both DFA α1 and DFA α2 were comparable in both groups. In receiver operating characteristic curve analysis, scale 5 had the greatest discriminatory power for two groups. In both net reclassification improvement model and integrated discrimination improvement models, MSE parameters significantly improved the discriminatory power of SDRR, pNN20, and pNN50. In conclusion, PD patients had worse cardiac complexity parameters. MSE parameters are useful to discriminate PD patients from patients with normal renal function.

  9. Practical stepwise approach to rhythm disturbances in congenital heart diseases.

    PubMed

    Huh, June

    2010-06-01

    Patients with congenital heart diseases (CHD) are confronted with early- and late-onset complications, such as conduction disorders, arrhythmias, myocardial dysfunction, altered coronary flow, and ischemia, throughout their lifetime despite successful hemodynamic and/or anatomical correction. Rhythm disturbance is a well-known and increasingly frequent cause of morbidity and mortality in patients with CHD. Predisposing factors to rhythm disturbances include underlying cardiac defects, hemodynamic changes as part of the natural history, surgical repair and related scarring, and residual hemodynamic abnormalities. Acquired factors such as aging, hypertension, diabetes, obesity, and others may also contribute to arrhythmogenesis in CHD. The first step in evaluating arrhythmias in CHD is to understand the complex anatomy and to find predisposing factors and hemodynamic abnormalities. A practical stepwise approach can lead to diagnosis and prompt appropriate interventions. Electrophysiological assessment and management should be done with integrated care of the underlying heart defects and hemodynamic abnormalities. Catheter ablation and arrhythmia surgery have been increasingly applied, showing increasing success rates with technological advancement despite complicated arrhythmia circuits in complex anatomy and the difficulty of access. Correction of residual hemodynamic abnormalities may be critical in the treatment of arrhythmia in patients with CHD. PMID:21189938

  10. Practical stepwise approach to rhythm disturbances in congenital heart diseases

    PubMed Central

    2010-01-01

    Patients with congenital heart diseases (CHD) are confronted with early- and late-onset complications, such as conduction disorders, arrhythmias, myocardial dysfunction, altered coronary flow, and ischemia, throughout their lifetime despite successful hemodynamic and/or anatomical correction. Rhythm disturbance is a well-known and increasingly frequent cause of morbidity and mortality in patients with CHD. Predisposing factors to rhythm disturbances include underlying cardiac defects, hemodynamic changes as part of the natural history, surgical repair and related scarring, and residual hemodynamic abnormalities. Acquired factors such as aging, hypertension, diabetes, obesity, and others may also contribute to arrhythmogenesis in CHD. The first step in evaluating arrhythmias in CHD is to understand the complex anatomy and to find predisposing factors and hemodynamic abnormalities. A practical stepwise approach can lead to diagnosis and prompt appropriate interventions. Electrophysiological assessment and management should be done with integrated care of the underlying heart defects and hemodynamic abnormalities. Catheter ablation and arrhythmia surgery have been increasingly applied, showing increasing success rates with technological advancement despite complicated arrhythmia circuits in complex anatomy and the difficulty of access. Correction of residual hemodynamic abnormalities may be critical in the treatment of arrhythmia in patients with CHD. PMID:21189938

  11. Heart rhythm complexity impairment in patients undergoing peritoneal dialysis

    PubMed Central

    Lin, Yen-Hung; Lin, Chen; Ho, Yi-Heng; Wu, Vin-Cent; Lo, Men-Tzung; Hung, Kuan-Yu; Liu, Li-Yu Daisy; Lin, Lian-Yu; Huang, Jenq-Wen; Peng, Chung-Kang

    2016-01-01

    Cardiovascular disease is one of the leading causes of death in patients with advanced renal disease. The objective of this study was to investigate impairments in heart rhythm complexity in patients with end-stage renal disease. We prospectively analyzed 65 patients undergoing peritoneal dialysis (PD) without prior cardiovascular disease and 72 individuals with normal renal function as the control group. Heart rhythm analysis including complexity analysis by including detrended fractal analysis (DFA) and multiscale entropy (MSE) were performed. In linear analysis, the PD patients had a significantly lower standard deviation of normal RR intervals (SDRR) and percentage of absolute differences in normal RR intervals greater than 20 ms (pNN20). Of the nonlinear analysis indicators, scale 5, area under the MSE curve for scale 1 to 5 (area 1–5) and 6 to 20 (area 6–20) were significantly lower than those in the control group. In DFA anaylsis, both DFA α1 and DFA α2 were comparable in both groups. In receiver operating characteristic curve analysis, scale 5 had the greatest discriminatory power for two groups. In both net reclassification improvement model and integrated discrimination improvement models, MSE parameters significantly improved the discriminatory power of SDRR, pNN20, and pNN50. In conclusion, PD patients had worse cardiac complexity parameters. MSE parameters are useful to discriminate PD patients from patients with normal renal function. PMID:27324066

  12. [Semi-automatic defibrillators does not always interpret heart rhythms correctly. Five patients were defibrillated despite non-shockable rhythms].

    PubMed

    Wangenheim, Burkard; Israelsson, Johan; Lindstaedt, Michael; Carlsson, Jörg

    2015-01-01

    Automated external defibrillators (AED) have become an important part of the »the chain of survival« in case of sudden cardiac arrest (SCA), where early defibrillation is lifesaving. The American Heart Association demands that AEDs have a specificity of >99 % to recognize normal sinus rhythm and >95 % for the other non-shockable rhythms. Reports on their performance in the field are scarce. We present five cases in which AED recommended shock for apparently non-shockable rhythms. This indicates the necessity to systematically reevaluate AED performance. PMID:26241809

  13. Alterations in the heart rate and activity rhythms of three orbital astronauts on a space mission.

    PubMed

    Liu, Zhizhen; Wan, Yufeng; Zhang, Lin; Tian, Yu; Lv, Ke; Li, Yinghui; Wang, Chunhui; Chen, Xiaoping; Chen, Shanguang; Guo, Jinhu

    2015-01-01

    Environmental factors in space are dramatically different from those on Earth. The spaceflight environment has been known to influence human physiology and behavior on orbital missions. In this study, we investigated alterations in the diurnal rhythms of activity and heart rate of three Chinese astronauts on a space mission. An analysis of the heart rate data showed a significant decrease in heart rate amplitudes during flight in all three subjects. The heart rate amplitudes of all the three astronauts were significantly dampened during flight, and the minimum as well as the maximum value of heart rate increased after flight. A phase shift in heart rate was observed in one of the three astronauts after flight. These results demonstrate the influence of spaceflight on heart physiology and function. In addition, a significant decrease in body trunk activity and rhythmicity occurred during flight, demonstrating that the spaceflight environment disturbs motion adaptation and diurnal activity rhythms. PMID:26177621

  14. Heart rate dynamics distinguish among atrial fibrillation, normal sinus rhythm and sinus rhythm with frequent ectopy.

    PubMed

    Carrara, Marta; Carozzi, Luca; Moss, Travis J; de Pasquale, Marco; Cerutti, Sergio; Ferrario, Manuela; Lake, Douglas E; Moorman, J Randall

    2015-09-01

    Atrial fibrillation (AF) is usually detected by inspection of the electrocardiogram waveform, a task made difficult when the signal is distorted by noise. The RR interval time series is more frequently available and accurate, yet linear and nonlinear time series analyses that detect highly varying and irregular AF are vulnerable to the common finding of frequent ectopy. We hypothesized that different nonlinear measures might capture characteristic features of AF, normal sinus rhythm (NSR), and sinus rhythm (SR) with frequent ectopy in ways that linear measures might not. To test this, we studied 2722 patients with 24 h ECG recordings in the University of Virginia Holter database. We found dynamical phenotypes for the three rhythm classifications. As expected, AF records had the highest variability and entropy, and NSR the lowest. SR with ectopy could be distinguished from AF, which had higher entropy, and from NSR, which had different fractal scaling, measured as higher detrended fluctuation analysis slope. With these dynamical phenotypes, we developed successful classification strategies, and the nonlinear measures improved on the use of mean and variability alone, even after adjusting for age. Final models using all variables had excellent performance, with positive predictive values for AF, NSR and SR with ectopy as high as 97, 98 and 90%, respectively. Since these classifiers can reliably detect rhythm changes utilizing segments as short as 10 min, we envision their application in noisy settings and in personal monitoring devices where only RR interval time series may be available. PMID:26246162

  15. Heart rhythm disturbances associated with rupatadine: a case series from the Spanish and Portuguese pharmacovigilance systems.

    PubMed

    Carvajal, A; Macías, D; Salado, I; Sáinz, M; Ortega, S; Campo, C; García del Pozo, J; Martín Arias, L H; Velasco, A; Gonçalves, S; Pombal, R; Carmona, R

    2009-05-01

    We searched the Spanish and Portuguese pharmacovigilance databases for spontaneous case reports of heart rhythm disturbances associated with rupatadine and other new H1 antihistamines. Five cases were found involving patients treated with rupatadine (13.9% of all reports relating to this drug). In all five cases, the reaction started after exposure and resolved when the drug was discontinued. In two cases, rupatadine was the only medication being taken by the patient, and no other condition that could explain the heart rhythm disturbances was diagnosed. The reporting odds ratio was 3.2 (95% confidence interval, 1.0-10.5). The reporting rate was 2 cases per 100,000 patients treated per year (95% confidence interval, 0.4-6.0). These results suggest a causal relationship between rupatadine and heart rhythm disturbances. PMID:19225450

  16. [Quantitative estimation of connection of the heart rate rhythm with motor activity in rat fetuses].

    PubMed

    Vdovichenko, N D; Timofeeva, O P; Bursian, A V

    2014-01-01

    In rat fetuses at E17-20 with preserved placental circulation with use of mathematical analysis there were revealed value and character of connections of slow wave oscillations of the heart rhythm with motor activity for 30 min of observation. In the software "PowerGraph 3.3.8", normalization and filtration of the studied signals were performed at three frequency diapasons: D1 - 0.02-0.2 Hz (5-50 s), D2 - 0.0083-0.02 Hz (50 s-2 min), and D3 - 0.0017-0.0083 Hz (2-10 min). The EMG curves filtrated by diapasons or piezograms were compared with periodograms in the corresponding diapasons of the heart rhythm variations. In the software "Origin 8.0", quantitative estimation of the degree of intersystemic interrelations for each frequency diapason was performed by Pearson correlation of coefficient, by the correlation connection value, and by the time shift of maximum of cross-correlation function. It has been established that in the frequency D1, regardless of age, the connection of heart rhythm oscillations with motor activity is expressed weakly. In the frequency diapason D2, the connection in most cases is located in the zone of weak and moderate correlations. In the multiminute diapason (D3), the connection is more pronounced. The number of animals that have a significant value of the correlation connection rises. The fetal MA fires in the decasecond diapason in all age groups are accompanied by short-time decelerations of the heart rhythms. In the minute diapason, there is observed a transition from positive connections at E17 and E18 to the negative ones at E19-20. Results of the study are considered in association with age-related changes of ratios of positive and negative oscillations of the heart rhythm change depending on the character of motor activity. PMID:25486813

  17. Reorganization of the brain and heart rhythm during autogenic meditation

    PubMed Central

    Kim, Dae-Keun; Rhee, Jyoo-Hi; Kang, Seung Wan

    2014-01-01

    The underlying changes in heart coherence that are associated with reported EEG changes in response to meditation have been explored. We measured EEG and heart rate variability (HRV) before and during autogenic meditation. Fourteen subjects participated in the study. Heart coherence scores were significantly increased during meditation compared to the baseline. We found near significant decrease in high beta absolute power, increase in alpha relative power and significant increases in lower (alpha) and higher (above beta) band coherence during 3~min epochs of heart coherent meditation compared to 3~min epochs of heart non-coherence at baseline. The coherence and relative power increase in alpha band and absolute power decrease in high beta band could reflect relaxation state during the heart coherent meditation. The coherence increase in the higher (above beta) band could reflect cortico-cortical local integration and thereby affect cognitive reorganization, simultaneously with relaxation. Further research is still needed for a confirmation of heart coherence as a simple window for the meditative state. PMID:24454283

  18. Delay-correlation landscape reveals characteristic time delays of brain rhythms and heart interactions.

    PubMed

    Lin, Aijing; Liu, Kang K L; Bartsch, Ronny P; Ivanov, Plamen Ch

    2016-05-13

    Within the framework of 'Network Physiology', we ask a fundamental question of how modulations in cardiac dynamics emerge from networked brain-heart interactions. We propose a generalized time-delay approach to identify and quantify dynamical interactions between physiologically relevant brain rhythms and the heart rate. We perform empirical analysis of synchronized continuous EEG and ECG recordings from 34 healthy subjects during night-time sleep. For each pair of brain rhythm and heart interaction, we construct a delay-correlation landscape (DCL) that characterizes how individual brain rhythms are coupled to the heart rate, and how modulations in brain and cardiac dynamics are coordinated in time. We uncover characteristic time delays and an ensemble of specific profiles for the probability distribution of time delays that underly brain-heart interactions. These profiles are consistently observed in all subjects, indicating a universal pattern. Tracking the evolution of DCL across different sleep stages, we find that the ensemble of time-delay profiles changes from one physiologic state to another, indicating a strong association with physiologic state and function. The reported observations provide new insights on neurophysiological regulation of cardiac dynamics, with potential for broad clinical applications. The presented approach allows one to simultaneously capture key elements of dynamic interactions, including characteristic time delays and their time evolution, and can be applied to a range of coupled dynamical systems. PMID:27044991

  19. QT interval variability in body surface ECG: measurement, physiological basis, and clinical value: position statement and consensus guidance endorsed by the European Heart Rhythm Association jointly with the ESC Working Group on Cardiac Cellular Electrophysiology.

    PubMed

    Baumert, Mathias; Porta, Alberto; Vos, Marc A; Malik, Marek; Couderc, Jean-Philippe; Laguna, Pablo; Piccirillo, Gianfranco; Smith, Godfrey L; Tereshchenko, Larisa G; Volders, Paul G A

    2016-06-01

    This consensus guideline discusses the electrocardiographic phenomenon of beat-to-beat QT interval variability (QTV) on surface electrocardiograms. The text covers measurement principles, physiological basis, and clinical value of QTV. Technical considerations include QT interval measurement and the relation between QTV and heart rate variability. Research frontiers of QTV include understanding of QTV physiology, systematic evaluation of the link between QTV and direct measures of neural activity, modelling of the QTV dependence on the variability of other physiological variables, distinction between QTV and general T wave shape variability, and assessing of the QTV utility for guiding therapy. Increased QTV appears to be a risk marker of arrhythmic and cardiovascular death. It remains to be established whether it can guide therapy alone or in combination with other risk factors. QT interval variability has a possible role in non-invasive assessment of tonic sympathetic activity. PMID:26823389

  20. [Structure peculiarities, conditions and factors preceding the development of heart rhythm disorder in Chernobyl cleanup workers].

    PubMed

    Khomaziuk, I M; Zlatohors'ka, Zh M; Kursina, N V; Nastina, O M; Sydorenko, H V

    2008-01-01

    3595 participants of liquidation of consequences of Chernobyl accident (LCA) have been follow-upped since 1986. Structure and factors prior the development of heart rhythm derangements, results of physical examination, tonometry, ECG daily monitoring with taking into account the variability of heart rhythm, data of echocardiography with Doppler analysis have been established in 742 patients. Extrasystolic arrhythmia (50.8%) and atrium fibrillation prevailed in clinical structure of clinical structure of heart rhythm disorders (HRD). Etiological factors of HRD in 91.1% of cases were ischemic heart disease (IHD), hypertension and especially their combination, in 4.6%--other disorders, 4.6%--idiopathic HRD. It is possible to address special significance among factors before the development of HRD the following ones: participation in LCA since 1986, shift team work, ionizing radiation > or = 25 c3B, negative thoughts and memory about these events, from style of living--smoking habit, professional contact with xenobiotics, increased levels of arterial pressure, cholesterin, body weight index. Especial attention should be given to as predictors of the development of HRD -increased myocardium weight index > or = 170 gr/M2, duration of common and painless myocardial ischemia, basal frequency of heart rhythm > or = 75 b./m. It was established reliable relation between ventricular extrasystole and decreased of common BCP (r = -0.57; P < 0.05), spectrum power, (r = -0.52; P < 0.05), correlation disorder between its components. It is logical there was influence caused by combination of factors arised in connection with Chernobyl accident, life style and structural and functional changes of myocardium, hypertension and ischemic heart disease which are often found in Chernobyl disaster fighters. PMID:19145816

  1. Masking of the circadian rhythms of heart rate and core temperature by the rest-activity cycle in man

    NASA Technical Reports Server (NTRS)

    Gander, Philippa H.; Connell, Linda J.; Graeber, R. Curtis

    1986-01-01

    Experiments were conducted to estimate the magnitude of the masking effect produced in humans by alternate periods of physical activity and rest or sleep on the circadian rhythms of heart rate and core temperature. The heart rate, rectal temperature, and nondominant wrist activity were monitored in 12 male subjects during 6 days of normal routine at home and during 6 days of controlled bed-rest regimen. The comparisons of averaged waveforms for the activity, heart rate, and temperature indicated that about 45 percent of the range of the circadian heart rate rhythm during normal routine and about 14 percent of the range of the circadian temperature rhythm were attributable to the effects of activity. The smaller effect of activity on the temperature rhythm may be partially attributable to the fact that core temperature is being more rigorously conserved than heart rate, at least during moderate exercise.

  2. Electrocardiographic imaging of heart rhythm disorders: from bench to bedside.

    PubMed

    Rudy, Yoram; Lindsay, Bruce D

    2015-03-01

    Noninvasive electrocardiographic imaging (ECGI; also called ECG mapping) can reconstruct potentials, electrograms, activation sequences, and repolarization patterns on the epicardial surface of the heart with high resolution. ECGI can possibly be used to quantify synchrony, identify potential responders/nonresponders to cardiac resynchronization therapy, and guide electrode placement for effective resynchronization therapy. This article provides a brief description of the ECGI procedure and selected previously published examples of its application in important clinical conditions, including heart failure, cardiac resynchronization therapy, atrial arrhythmias, and ventricular tachycardia. PMID:25722753

  3. Effect of suprachiasmatic lesions on diurnal heart rate rhythm in the rat

    NASA Technical Reports Server (NTRS)

    Saleh, M. A.; Winget, C. M.

    1977-01-01

    Heart rate and locomotor activity of rats kept under 12L/12D illumination regimen were recorded every six minutes for ten days using implantable radio transmitters. Some of the rats then received bilateral RF lesions into the suprachiasmatic nucleus (SCN). Control sham operations were performed on the rest of the animals. After recovery from surgery, recording of heart rate and locomotor activity was continued for ten days. SCN-lesioned rats showed no significant diurnal fluctuation in heart rate, while normal and sham-operated rats showed the normal diurnal rhythm in that function. The arrhythmic diurnal heart-rate pattern of SCN rats appeared to be correlated with their sporadic activity pattern. The integrity of the suprachiasmatic nucleus is therefore necessary for the generation and/or expression of diurnal rhythmicity in heart rate in the rat.

  4. Demand-feeding rhythm in rainbow trout and European catfish. Synchronisation by photoperiod and food availability.

    PubMed

    Bolliet, V; Aranda, A; Boujard, T

    2001-07-01

    The effect of light-dark (LD) cycle and food availability was tested on the demand-feeding rhythm of single and groups of rainbow trout and European catfish. Under LD and free food access, most trout and catfish displayed, respectively, a diurnal and a nocturnal pattern of demand-feeding activity, whereas a few fish or groups of fish switched from diurnalism to nocturnalism or vice versa. In both species held under constant lighting conditions and a restricted feeding (RF) cycle (RF 20:4), the demand-feeding rhythm rapidly synchronised to food availability. The demand-feeding rhythm was under endogenous control and, in rainbow trout, periodogram analysis suggested the existence of two oscillators, one synchronised by photoperiod (LEO) and the other by food (FEO). When submitted to both LD and RF cycles, LD was, at least in the rainbow trout, the dominant zeitgeber synchronising the demand-feeding rhythm. In catfish, food availability rapidly synchronised demand-feeding rhythm. Finally, in both species, the synchronisation of single fish to LD or feed availability appeared slower than that of groups of fish, supporting the idea that social organisation affects the circadian activity in fish. PMID:11495668

  5. Computation of nonlinear parameters of heart rhythm using short time ECG segments.

    PubMed

    Koichubekov, Berik; Korshukov, Ilya; Omarbekova, Nazgul; Riklefs, Viktor; Sorokina, Marina; Mkhitaryan, Xenia

    2015-01-01

    We propose the method to compute the nonlinear parameters of heart rhythm (correlation dimension D₂ and correlation entropy K₂) using 5-minute ECG recordings preferred for screening of population. Conversion of RR intervals' time series into continuous function x(t) allows getting the new time series with different sampling rate dt. It has been shown that for all dt (250, 200, 125, and 100 ms) the cross-plots of D₂ and K₂ against embedding dimension m for phase-space reconstruction start to level off at m = 9. The sample size N at different sampling rates varied from 1200 at dt = 250 ms to 3000 at dt = 100 ms. Along with, the D₂ and K₂ means were not statistically different; that is, the sampling rate did not influence the results. We tested the feasibility of the method in two models: nonlinear heart rhythm dynamics in different states of autonomous nervous system and age-related characteristics of nonlinear parameters. According to the acquired data, the heart rhythm is more complex in childhood and adolescence with more influential parasympathetic influence against the background of elevated activity of sympathetic autonomous nervous system. PMID:25688286

  6. Black Holes Are The Rhythm at The Heart of Galaxies

    NASA Astrophysics Data System (ADS)

    2008-11-01

    The powerful black holes at the center of massive galaxies and galaxy clusters act as hearts to the systems, pumping energy out at regular intervals to regulate the growth of the black holes themselves, as well as star formation, according to new data from NASA's Chandra X-Ray Observatory. People Who Read This Also Read... Milky Way’s Giant Black Hole Awoke from Slumber 300 Years Ago A New Way To Weigh Giant Black Holes Discovery of Most Recent Supernova in Our Galaxy NASA Unveils Cosmic Images Book in Braille for Blind Readers Scientists from the University of Michigan, the Max-Planck Institute for Extraterrestrial Physics in Germany, the University of Maryland, Baltimore County (UMBC), the Harvard-Smithsonian Center for Astrophysics and Jacobs University in Germany contributed to the results. The gravitational pull of black holes is so strong that not even light can escape from them. Supermassive black holes with masses of more than a billion suns have been detected at the center of large galaxies. The material falling on the black holes causes sporadic or isolated bursts of energy, by which black holes are capable of influencing the fate of their host galaxies. The insight gained by this new research shows that black holes can pump energy in a gentler and rhythmic fashion, rather then violently. The scientists observed and simulated how the black hole at the center of elliptical galaxy M84 dependably sends bubbles of hot plasma into space, heating up interstellar space. This heat is believed to slow both the formation of new stars and the growth of the black hole itself, helping the galaxy remain stable. Interstellar gases only coalesce into new stars when the gas is cool enough. The heating is more efficient at the sites where it is most needed, the scientists say. Alexis Finoguenov, of UMBC and the Max-Planck Institute for Extraterrestrial Physics in Germany, compares the central black hole to a heart muscle. "Just like our hearts periodically pump our

  7. Heart rate and respiratory rhythm dynamics on ascent to high altitude

    NASA Technical Reports Server (NTRS)

    Lipsitz, L. A.; Hashimoto, F.; Lubowsky, L. P.; Mietus, J.; Moody, G. B.; Appenzeller, O.; Goldberger, A. L.

    1995-01-01

    OBJECTIVE--To investigate the alterations in autonomic control of heart rate at high altitude and to test the hypothesis that hypoxaemic stress during exposure to high altitude induces non-linear, periodic heart rate oscillations, similar to those seen in heart failure and the sleep apnoea syndrome. SUBJECTS--11 healthy subjects aged 24-64. MAIN OUTCOME MEASURES--24 hour ambulatory electrocardiogram records obtained at baseline (1524 m) and at 4700 m. Simultaneous heart rate and respiratory dynamics during 2.5 hours of sleep by fast Fourier transform analysis of beat to beat heart rate and of an electrocardiographically derived respiration signal. RESULTS--All subjects had resting hypoxaemia at high altitude, with an average oxyhaemoglobin saturation of 81% (5%). There was no significant change in mean heart rate, but low frequency (0.01-0.05 Hz) spectral power was increased (P < 0.01) at high altitude. Time series analysis showed a complex range of non-linear sinus rhythm dynamics. Striking low frequency (0.04-0.06 Hz) heart rate oscillations were observed during sleep in eight subjects at high altitude. Analysis of the electrocardiographically derived respiration signal indicated that these heart rate oscillations correlated with low frequency respiratory oscillations. CONCLUSIONS--These data suggest (a) that increased low frequency power during high altitude exposure is not simply attributable to increased sympathetic modulation of heart rate, but relates to distinctive cardiopulmonary oscillations at approximately 0.05 Hz and (b) that the emergence of periodic heart rate oscillations at high altitude is consistent with an unstable cardiopulmonary control system that may develop on acute exposure to hypoxaemic stress.

  8. Alignment of R-R interval signals using the circadian heart rate rhythm.

    PubMed

    Gayraud, Nathalie T H; Manis, George

    2015-01-01

    R-R interval signals that come from different subjects are regularly aligned and averaged according to the horological starting time of the recordings. We argue that the horological time is a faulty alignment criterion and provide evidence in the form of a new alignment method. Our main motivation is that the human heart rate (HR) rhythm follows a circadian cycle, whose pattern can vary among different classes of people. We propose two novel alignment algorithms that consider the HR circadian rhythm, the Puzzle Piece Alignment Algorithm (PPA) and the Event Based Alignment Algorithm (EBA). First, we convert the R-R interval signal into a series of time windows and compute the mean HR per window. Then our algorithms search for matching circadian patterns to align the signals. We conduct experiments using R-R interval signals extracted from two databases in the Physionet Data Bank. Both algorithms are able to align the signals with respect to the circadian rhythmicity of HR. Furthermore, our findings confirm the presence of more than one pattern in the circadian HR rhythm. We suggest an automatic classification of signals according to the three most prominent patterns. PMID:26737009

  9. Low dimensional model of heart rhythm dynamics as a tool for diagnosing the anaerobic threshold

    SciTech Connect

    Anosov, O.L.; Butkovskii, O.Y.; Kadtke, J.; Kravtsov, Y.A.

    1997-05-01

    We report preliminary results on describing the dependence of the heart rhythm variability on the stress level by using qualitative, low dimensional models. The reconstruction of macroscopic heart models yielding cardio cycles (RR-intervals) duration was based on actual clinical data. Our results show that the coefficients of the low dimensional models are sensitive to metabolic changes. In particular, at the transition between aerobic and aerobic-anaerobic metabolism, there are pronounced extrema in the functional dependence of the coefficients on the stress level. This strong sensitivity can be used to design an easy indirect method for determining the anaerobic threshold. This method could replace costly and invasive traditional methods such as gas analysis and blood tests. {copyright} {ital 1997 American Institute of Physics.}

  10. Proceedings from Heart Rhythm Society's emerging technologies forum, Boston, MA, May 12, 2015.

    PubMed

    Zeitler, Emily P; Al-Khatib, Sana M; Slotwiner, David; Kumar, Uday N; Varosy, Paul; Van Wagoner, David R; Marcus, Gregory M; Kusumoto, Fred M; Blum, Laura

    2016-02-01

    Physicians are in an excellent position to significantly contribute to medical device innovation, but the process of bringing an idea to the bedside is complex. To begin to address these perceived barriers, the Heart Rhythm Society convened a forum of stakeholders in medical device innovation in conjunction with the 2015 Heart Rhythm Society Annual Scientific Sessions. The forum facilitated open discussion on medical device innovation, including obstacles to physician involvement and possible solutions. This report is based on the themes that emerged. First, physician innovators must take an organized approach to identifying unmet clinical needs and potential solutions. Second, extensive funds, usually secured through solicitation for investment, are often required to achieve meaningful progress, developing an idea into a device. Third, planning for regulatory requirements of the US Food and Drug Administration and Centers for Medicare & Medicaid Services is essential. In addition to these issues, intellectual property and overall trends in health care, including international markets, are critically relevant considerations for the physician innovator. Importantly, there are a number of ways in which professional societies can assist physician innovators to navigate the complex medical device innovation landscape, bring clinically meaningful devices to market more quickly, and ultimately improve patient care. These efforts include facilitating interaction between potential collaborators through scientific meetings and other gatherings; collecting, evaluating, and disseminating state-of-the-art scientific information; and representing the interests of members in interactions with regulators and policymakers. PMID:26801401

  11. Improvement of Circadian Rhythm of Heart Rate Variability by Eurythmy Therapy Training

    PubMed Central

    Seifert, Georg; Kanitz, Jenny-Lena; Pretzer, Kim; Henze, Günter; Witt, Katharina; Reulecke, Sina; Voss, Andreas

    2013-01-01

    Background. Impairment of circadian rhythm is associated with various clinical problems. It not only has a negative impact on quality of life but can also be associated with a significantly poorer prognosis. Eurythmy therapy (EYT) is an anthroposophic movement therapy aimed at reducing fatigue symptoms and stress levels. Objective. This analysis of healthy subjects was conducted to examine whether the improvement in fatigue symptoms was accompanied by improvements in the circadian rhythm of heart rate variability (HRV). Design. Twenty-three women performed 10 hours of EYT over six weeks. Electrocardiograms (ECGs) were recorded before and after the EYT trial. HRV was quantified by parameters of the frequency and time domains and the nonlinear parameters of symbolic dynamics. Results. The day-night contrast with predominance of vagal activity at night becomes more pronounced after the EYT training, and with decreased Ultralow and very low frequencies, the HRV shows evidence of calmer sleep. During the night, the complexity of the HRV is significantly increased indicated by nonlinear parameters. Conclusion. The analysis of the circadian patterns of cardiophysiological parameters before and after EYT shows significant improvements in HRV in terms of greater day-night contrast caused by an increase of vagal activity and calmer and more complex HRV patterns during sleep. PMID:23533496

  12. [Individual peculiarities of adaptation to long-term space flights: 24-hour heart rhythm monitoring

    NASA Technical Reports Server (NTRS)

    Baevskii, R. M.; Bogomolov, V. V.; Gol'dberger, A. L.; Nikulina, G. A.; Charl'z, D. B.; Goldberger, A. L. (Principal Investigator); Charles, J. B. (Principal Investigator)

    2000-01-01

    Presented are results of studying 24-hr variability of the cardiac rhythm which characterizes individual difference in reactions of two crew members to the same set of stresses during a 115-day MIR mission. Spacelab (USA) cardiorecorders were used. Data of monitoring revealed significantly different baseline health statuses of the cosmonauts. These functional differences were also observed in the mission. In one of the cosmonauts, the cardiac regulation changed over to a more economic functioning with the autonomous balance shifted towards enhanced sympathetic activity. After 2-3 months on mission he had almost recovered pre-launch level of regulation. In the other, the regulatory system was appreciably strained at the beginning of the mission as compared with preflight baseline. Later on, on flight months 2-3, this strain kept growing till a drastic depletion of the functional reserve. On return to Earth, this was manifested by a strong stress reaction with a sharp decline in power of high-frequency and grow in power of very low frequency components of the heart rhythm. The data suggest that adaptation to space flight and reactions in the readaptation period are dependent on initial health status of crew members, and functional reserve.

  13. Circadian rhythms (temperature, heart rate, vigilance, mood) of short and long sleepers: effects of sleep deprivation.

    PubMed

    Benoit, O; Foret, J; Merle, B; Reinberg, A

    1981-01-01

    Seven long sleepers (LS) (sleep greater than or equal to 9 h) and seven short sleepers (SS) (sleep less than or equal to 7 h), aged 20 to 23 years, were selected among medical students. They measured their axillary temperature (T), heart rate (HR) and self-estimated their vigilance (V) and mood (M) every 4 h from awakening to bed time during a ten-day control span and during the two sleep deprived nights. Polygraphic sleep recordings were performed on 3 control days and recovery from 24 h (day sleep) or 36 h (night sleep) sleep deprivations. For the 4 variables (T, HR, V and M), group circadian patterns were analyzed by means of the cosinor method for the control span and after both types of sleep deprivation. The acrophases of the 4 variables clustered more in LS than in SS. The acrophases of V and M were found to be more closely related to the sleep/wake rhythm than those of T and HR. Sleep deprivation resulted in a large change of the circadian rhythms in LS but had little effect in SS as indicated by the non detection of most acrophases in LS and the persistence of such acrophases in SS. This difference might be explained by the large interindividual variability of changes induced by the sleep deprivation in LS. Moreover, day sleep recovery was more disturbed in LS than in SS. PMID:7327054

  14. Mutations in SGOL1 cause a novel cohesinopathy affecting heart and gut rhythm.

    PubMed

    Chetaille, Philippe; Preuss, Christoph; Burkhard, Silja; Côté, Jean-Marc; Houde, Christine; Castilloux, Julie; Piché, Jessica; Gosset, Natacha; Leclerc, Séverine; Wünnemann, Florian; Thibeault, Maryse; Gagnon, Carmen; Galli, Antonella; Tuck, Elizabeth; Hickson, Gilles R; El Amine, Nour; Boufaied, Ines; Lemyre, Emmanuelle; de Santa Barbara, Pascal; Faure, Sandrine; Jonzon, Anders; Cameron, Michel; Dietz, Harry C; Gallo-McFarlane, Elena; Benson, D Woodrow; Moreau, Claudia; Labuda, Damian; Zhan, Shing H; Shen, Yaoqing; Jomphe, Michèle; Jones, Steven J M; Bakkers, Jeroen; Andelfinger, Gregor

    2014-11-01

    The pacemaking activity of specialized tissues in the heart and gut results in lifelong rhythmic contractions. Here we describe a new syndrome characterized by Chronic Atrial and Intestinal Dysrhythmia, termed CAID syndrome, in 16 French Canadians and 1 Swede. We show that a single shared homozygous founder mutation in SGOL1, a component of the cohesin complex, causes CAID syndrome. Cultured dermal fibroblasts from affected individuals showed accelerated cell cycle progression, a higher rate of senescence and enhanced activation of TGF-β signaling. Karyotypes showed the typical railroad appearance of a centromeric cohesion defect. Tissues derived from affected individuals displayed pathological changes in both the enteric nervous system and smooth muscle. Morpholino-induced knockdown of sgol1 in zebrafish recapitulated the abnormalities seen in humans with CAID syndrome. Our findings identify CAID syndrome as a novel generalized dysrhythmia, suggesting a new role for SGOL1 and the cohesin complex in mediating the integrity of human cardiac and gut rhythm. PMID:25282101

  15. Diel rhythms of feeding activity in the European catfish, Silurus glanis.

    PubMed

    Boujard, T

    1995-10-01

    The diel rhythms of feeding activity of S. glanis held singly or in groups, and with free or time-restricted access to self-feeders is described. It was found that this this species has a strongly nocturnal feeding activity. European catfish can be trained to feed itself by day, but in such case its voluntary feed intake is reduced. When trained to feed by day, they resume their nocturnal behavior in less than 24 h when they have again free access to feed. It is also clearly evidenced that this fish species does not behave the same way when it is isolated from its congeneres rather than when it is maintained in groups, with a tendency to become arhythmic. PMID:8559771

  16. Heart Rhythm Monitoring in the Constellation Lunar and Launch/Landing EVA Suit: Recommendations from an Expert Panel

    NASA Technical Reports Server (NTRS)

    Scheuring, Richard A.; Hamilton, Doug; Jones, Jeffrey A.; Alexander, David

    2009-01-01

    There are currently several physiological monitoring requirements for EVA in the Human-Systems Interface Requirements (HSIR) document. There are questions as to whether the capability to monitor heart rhythm in the lunar surface space suit is a necessary capability for lunar surface operations. Similarly, there are questions as to whether the capability to monitor heart rhythm during a cabin depressurization scenario in the launch/landing space suit is necessary. This presentation seeks to inform space medicine personnel of recommendations made by an expert panel of cardiovascular medicine specialists regarding in-suit ECG heart rhythm monitoring requirements during lunar surface operations. After a review of demographic information and clinical cases and panel discussion, the panel recommended that ECG monitoring capability as a clinical tool was not essential in the lunar space suit; ECG monitoring was not essential in the launch/landing space suit for contingency scenarios; the current hear rate monitoring capability requirement for both launch/landing and lunar space suits should be maintained; lunar vehicles should be required to have ECG monitoring capability with a minimum of 5-lead ECG for IVA medical assessments; and, exercise stress testing for astronaut selection and retention should be changed from the current 85% maximum heart rate limit to maximal, exhaustive 'symptom-limited' testing to maximize diagnostic utility as a screening tool for evaluating the functional capacity of astronauts and their cardiovascular health.

  17. Circadian rhythm phase shifts and endogenous free-running circadian period differ between African-Americans and European-Americans

    PubMed Central

    Eastman, Charmane I.; Suh, Christina; Tomaka, Victoria A.; Crowley, Stephanie J.

    2015-01-01

    Successful adaptation to modern civilization requires the internal circadian clock to make large phase shifts in response to circumstances (e.g., jet travel and shift work) that were not encountered during most of our evolution. We found that the magnitude and direction of the circadian clock's phase shift after the light/dark and sleep/wake/meal schedule was phase-advanced (made earlier) by 9 hours differed in European-Americans compared to African-Americans. European-Americans had larger phase shifts, but were more likely to phase-delay after the 9-hour advance (to phase shift in the wrong direction). The magnitude and direction of the phase shift was related to the free-running circadian period, and European-Americans had a longer circadian period than African-Americans. Circadian period was related to the percent Sub-Saharan African and European ancestry from DNA samples. We speculate that a short circadian period was advantageous during our evolution in Africa and lengthened with northern migrations out of Africa. The differences in circadian rhythms remaining today are relevant for understanding and treating the modern circadian-rhythm-based disorders which are due to a misalignment between the internal circadian rhythms and the times for sleep, work, school and meals. PMID:25670162

  18. Heart Rhythm Monitoring in the Constellation Lunar and Launch/Landing EVA Suit: Recommendations from an Expert Panel

    NASA Technical Reports Server (NTRS)

    Scheuring, Richard A.; Hamilton, D.; Jones, J. A.; Alexander, D.

    2008-01-01

    Currently there are several physiological monitoring requirements for Extravehicular Activity (EVA) in the Human-Systems Interface Requirements (HSIR) document, including continuous heart rhythm monitoring. However, it is not known whether heart rhythm monitoring in the lunar surface space suit is a necessary capability for lunar surface operations or in launch/landing suit the event of a cabin depressurization enroute to or from the moon. Methods: Current US astronaut corps demographic information was provided to an expert panel of cardiovascular medicine experts, including specialists in electrophysiology, exercise physiology, interventional cardiology and arrhythmia. This information included averages for male/female age, body mass index (BMI), blood pressure, cholesterol, inflammatory markers, echocardiogram, ranges for coronary artery calcium (CAC) scores for long duration astronauts, and ranges for heart rate (HR) and metabolic (MET) rates obtained during microgravity and lunar EVA. Results: The panel determined that no uncontrolled hazard was likely to occur in the suit during lunar surface or contingency microgravity ops that would require ECG monitoring in the highly screened US astronaut population. However having the capability for rhythm monitoring inside the vehicle (IVA) was considered critical to manage an astronaut in distress. Discussion: Heart rate (HR) monitoring alone allows effective monitoring of astronaut health and function. Consequently, electrocardiographic (ECG) monitoring capability as a clinical tool is not essential in the lunar or launch/landing space suit. However, the panel considered that rhythm monitoring could be useful in certain clinical situations, it was not considered required for safe operations. Also, lunar vehicles should be required to have ECG monitoring capability with a minimum of 5-lead ECG (derived 12- lead) for IVA medical assessments.

  19. Detection and significance of a discrete very low frequency rhythm in RR interval variability in chronic congestive heart failure.

    PubMed

    Ponikowski, P; Chua, T P; Amadi, A A; Piepoli, M; Harrington, D; Volterrani, M; Colombo, R; Mazzuero, G; Giordano, A; Coats, A J

    1996-06-15

    Although in advanced chronic congestive heart failure (CHF) very low frequency (< 0.04 Hz, VLF) oscillations are prominent, the clinical importance and the physiologic basis of these rhythms have not been elucidated. To investigate the physiologic determinants of the VLF rhythms in RR interval variability, we studied 36 patients with stable, moderate to severe CHF (33 men, age: 58 +/- 8 years, ejection fraction 25 +/- 10%, peak oxygen consumption 18.1 +/- 4.6 ml/kg/min) and 12 age- and sex-matched controls using autoregressive spectral analysis of RR interval, blood pressure, and respiratory signals during controlled conditions. We quantified low frequency (LF) (0.04 to 0.15 Hz), high frequency (HF) (0.15 to 0.40 Hz), VLF, and total power (0 to 0.5 Hz), and calculated the coherence between systolic blood pressure and RR interval variability within each band. Peripheral chemosensitivity was assessed by the ventilatory response to hypoxia using transient inhalation of pure nitrogen. The influence of transient inactivation of peripheral chemoreceptors on the VLF rhythm was investigated by exposing 6 patients to hyperoxic (60% oxygen) conditions for 20 minutes. Twenty-three patients (64%) with CHF, but no controls, had a discrete VLF rhythm (0.019 +/- 0.008 Hz) in RR variability. The presence of VLF rhythm was not related to any difference in clinical parameters (etiology, New York Heart Association class, ejection fraction, oxygen uptake) but rather to a different pattern in RR interval and blood pressure variability: lower LF power (2.8 +/- 1.6 ms2 natural logarithm [ln]) compared either to patients without VLF (4.0 +/- 1.3 ms2 ln) or to controls (5.9 +/- 0.7 ms2 ln), higher percentage of power within VLF band (86.3 +/- 8.3% vs 77.5 +/- 7.9% and 61.5 +/- 14.1%) and a markedly impaired coherence between RR interval and systolic blood pressure variability within the LF band (0.26 +/- 0.10 vs 0.42 +/- 0.18 and 0.63 +/- 0.15, in patients with vs without VLF peak and

  20. Heart Failure Association of the European Society of Cardiology heart failure nurse curriculum.

    PubMed

    Riley, Jillian P; Astin, Felicity; Crespo-Leiro, Marisa G; Deaton, Christi M; Kienhorst, Jens; Lambrinou, Ekaterini; McDonagh, Theresa A; Rushton, Claire A; Stromberg, Anna; Filippatos, Gerasimos; Anker, Stefan D

    2016-07-01

    Recent advances in care and management of heart failure have improved outcome, largely as a result of the developing evidence basis for medications, implantable devices and the organization of heart failure follow-up. Such developments have also increased the complexity of delivering and coordinating care. This has led to a change to the way in which heart failure services are organized and to the traditional role of the heart failure nurse. Nurses in many countries now provide a range of services that include providing care for patients with acute and with chronic heart failure, working in and across different sectors of care (inpatient, outpatient, community care, the home and remotely), organising care services around the face-to-face and the remote collection of patient data, and liaising with a wide variety of health-care providers and professionals. To support such advances the nurse requires a skill set that goes beyond that of their initial education and training. The range of nurses' roles across Europe is varied. So too is the nature of their educational preparation. This heart failure nurse curriculum aims to provide a framework for use in countries of the European Society of Cardiology. Its modular approach enables the key knowledge, skills, and behaviours for the nurse working in different care settings to be outlined and so facilitate nursing staff to play a fuller role within the heart failure team. PMID:27220672

  1. Biological rhythms

    NASA Technical Reports Server (NTRS)

    Halberg, F.

    1975-01-01

    An overview is given of basic features of biological rhythms. The classification of periodic behavior of physical and psychological characteristics as circadian, circannual, diurnal, and ultradian is discussed, and the notion of relativistic time as it applies in biology is examined. Special attention is given to circadian rhythms which are dependent on the adrenocortical cycle. The need for adequate understanding of circadian variations in the basic physiological indicators of an individual (heart rate, body temperature, systolic and diastolic blood pressure, etc.) to ensure the effectiveness of prophylactic and therapeutic measures is stressed.

  2. Identification of heart rate–associated loci and their effects on cardiac conduction and rhythm disorders

    PubMed Central

    den Hoed, Marcel; Eijgelsheim, Mark; Esko, Tõnu; Brundel, Bianca J J M; Peal, David S; Evans, David M; Nolte, Ilja M; Segrè, Ayellet V; Holm, Hilma; Handsaker, Robert E; Westra, Harm-Jan; Johnson, Toby; Isaacs, Aaron; Yang, Jian; Lundby, Alicia; Zhao, Jing Hua; Kim, Young Jin; Go, Min Jin; Almgren, Peter; Bochud, Murielle; Boucher, Gabrielle; Cornelis, Marilyn C; Gudbjartsson, Daniel; Hadley, David; Van Der Harst, Pim; Hayward, Caroline; Heijer, Martin Den; Igl, Wilmar; Jackson, Anne U; Kutalik, Zoltán; Luan, Jian’an; Kemp, John P; Kristiansson, Kati; Ladenvall, Claes; Lorentzon, Mattias; Montasser, May E; Njajou, Omer T; O’Reilly, Paul F; Padmanabhan, Sandosh; Pourcain, Beate St.; Rankinen, Tuomo; Salo, Perttu; Tanaka, Toshiko; Timpson, Nicholas J; Vitart, Veronique; Waite, Lindsay; Wheeler, William; Zhang, Weihua; Draisma, Harmen H M; Feitosa, Mary F; Kerr, Kathleen F; Lind, Penelope A; Mihailov, Evelin; Onland-Moret, N Charlotte; Song, Ci; Weedon, Michael N; Xie, Weijia; Yengo, Loic; Absher, Devin; Albert, Christine M; Alonso, Alvaro; Arking, Dan E; de Bakker, Paul I W; Balkau, Beverley; Barlassina, Cristina; Benaglio, Paola; Bis, Joshua C; Bouatia-Naji, Nabila; Brage, Søren; Chanock, Stephen J; Chines, Peter S; Chung, Mina; Darbar, Dawood; Dina, Christian; Dörr, Marcus; Elliott, Paul; Felix, Stephan B; Fischer, Krista; Fuchsberger, Christian; de Geus, Eco J C; Goyette, Philippe; Gudnason, Vilmundur; Harris, Tamara B; Hartikainen, Anna-liisa; Havulinna, Aki S; Heckbert, Susan R; Hicks, Andrew A; Hofman, Albert; Holewijn, Suzanne; Hoogstra-Berends, Femke; Hottenga, Jouke-Jan; Jensen, Majken K; Johansson, Åsa; Junttila, Juhani; Kääb, Stefan; Kanon, Bart; Ketkar, Shamika; Khaw, Kay-Tee; Knowles, Joshua W; Kooner, Angrad S; Kors, Jan A; Kumari, Meena; Milani, Lili; Laiho, Päivi; Lakatta, Edward G; Langenberg, Claudia; Leusink, Maarten; Liu, Yongmei; Luben, Robert N; Lunetta, Kathryn L; Lynch, Stacey N; Markus, Marcello R P; Marques-Vidal, Pedro; Leach, Irene Mateo; McArdle, Wendy L; McCarroll, Steven A; Medland, Sarah E; Miller, Kathryn A; Montgomery, Grant W; Morrison, Alanna C; Müller-Nurasyid, Martina; Navarro, Pau; Nelis, Mari; O’Connell, Jeffrey R; O’Donnell, Christopher J; Ong, Ken K; Newman, Anne B; Peters, Annette; Polasek, Ozren; Pouta, Anneli; Pramstaller, Peter P; Psaty, Bruce M; Rao, Dabeeru C; Ring, Susan M; Rossin, Elizabeth J; Rudan, Diana; Sanna, Serena; Scott, Robert A; Sehmi, Jaban S; Sharp, Stephen; Shin, Jordan T; Singleton, Andrew B; Smith, Albert V; Soranzo, Nicole; Spector, Tim D; Stewart, Chip; Stringham, Heather M; Tarasov, Kirill V; Uitterlinden, André G; Vandenput, Liesbeth; Hwang, Shih-Jen; Whitfield, John B; Wijmenga, Cisca; Wild, Sarah H; Willemsen, Gonneke; Wilson, James F; Witteman, Jacqueline C M; Wong, Andrew; Wong, Quenna; Jamshidi, Yalda; Zitting, Paavo; Boer, Jolanda M A; Boomsma, Dorret I; Borecki, Ingrid B; Van Duijn, Cornelia M; Ekelund, Ulf; Forouhi, Nita G; Froguel, Philippe; Hingorani, Aroon; Ingelsson, Erik; Kivimaki, Mika; Kronmal, Richard A; Kuh, Diana; Lind, Lars; Martin, Nicholas G; Oostra, Ben A; Pedersen, Nancy L; Quertermous, Thomas; Rotter, Jerome I; van der Schouw, Yvonne T; Verschuren, W M Monique; Walker, Mark; Albanes, Demetrius; Arnar, David O; Assimes, Themistocles L; Bandinelli, Stefania; Boehnke, Michael; de Boer, Rudolf A; Bouchard, Claude; Caulfield, W L Mark; Chambers, John C; Curhan, Gary; Cusi, Daniele; Eriksson, Johan; Ferrucci, Luigi; van Gilst, Wiek H; Glorioso, Nicola; de Graaf, Jacqueline; Groop, Leif; Gyllensten, Ulf; Hsueh, Wen-Chi; Hu, Frank B; Huikuri, Heikki V; Hunter, David J; Iribarren, Carlos; Isomaa, Bo; Jarvelin, Marjo-Riitta; Jula, Antti; Kähönen, Mika; Kiemeney, Lambertus A; van der Klauw, Melanie M; Kooner, Jaspal S; Kraft, Peter; Iacoviello, Licia; Lehtimäki, Terho; Lokki, Marja-Liisa L; Mitchell, Braxton D; Navis, Gerjan; Nieminen, Markku S; Ohlsson, Claes; Poulter, Neil R; Qi, Lu; Raitakari, Olli T; Rimm, Eric B; Rioux, John D; Rizzi, Federica; Rudan, Igor; Salomaa, Veikko; Sever, Peter S; Shields, Denis C; Shuldiner, Alan R; Sinisalo, Juha; Stanton, Alice V; Stolk, Ronald P; Strachan, David P; Tardif, Jean-Claude; Thorsteinsdottir, Unnur; Tuomilehto, Jaako; van Veldhuisen, Dirk J; Virtamo, Jarmo; Viikari, Jorma; Vollenweider, Peter; Waeber, Gérard; Widen, Elisabeth; Cho, Yoon Shin; Olsen, Jesper V; Visscher, Peter M; Willer, Cristen; Franke, Lude; Erdmann, Jeanette; Thompson, John R; Pfeufer, Arne; Sotoodehnia, Nona

    2013-01-01

    Elevated resting heart rate is associated with greater risk of cardiovascular disease and mortality. In a 2-stage meta-analysis of genome-wide association studies in up to 181,171 individuals, we identified 14 new loci associated with heart rate and confirmed associations with all 7 previously established loci. Experimental downregulation of gene expression in Drosophila melanogaster and Danio rerio identified 20 genes at 11 loci that are relevant for heart rate regulation and highlight a role for genes involved in signal transmission, embryonic cardiac development and the pathophysiology of dilated cardiomyopathy, congenital heart failure and/or sudden cardiac death. In addition, genetic susceptibility to increased heart rate is associated with altered cardiac conduction and reduced risk of sick sinus syndrome, and both heart rate–increasing and heart rate–decreasing variants associate with risk of atrial fibrillation. Our findings provide fresh insights into the mechanisms regulating heart rate and identify new therapeutic targets. PMID:23583979

  3. Ecstasy (MDMA) Alters Cardiac Gene Expression and DNA Methylation: Implications for Circadian Rhythm Dysfunction in the Heart.

    PubMed

    Koczor, Christopher A; Ludlow, Ivan; Hight, Robert S; Jiao, Zhe; Fields, Earl; Ludaway, Tomika; Russ, Rodney; Torres, Rebecca A; Lewis, William

    2015-11-01

    MDMA (ecstasy) is an illicit drug that stimulates monoamine neurotransmitter release and inhibits reuptake. MDMA's acute cardiotoxicity includes tachycardia and arrhythmia which are associated with cardiomyopathy. MDMA acute cardiotoxicity has been explored, but neither long-term MDMA cardiac pathological changes nor epigenetic changes have been evaluated. Microarray analyses were employed to identify cardiac gene expression changes and epigenetic DNA methylation changes. To identify permanent MDMA-induced pathogenetic changes, mice received daily 10- or 35-day MDMA, or daily 10-day MDMA followed by 25-day saline washout (10 + 25 days). MDMA treatment caused differential gene expression (p < .05, fold change >1.5) in 752 genes following 10 days, 558 genes following 35 days, and 113 genes following 10-day MDMA + 25-day saline washout. Changes in MAPK and circadian rhythm gene expression were identified as early as 10 days. After 35 days, circadian rhythm genes (Per3, CLOCK, ARNTL, and NPAS2) persisted to be differentially expressed. MDMA caused DNA hypermethylation and hypomethylation that was independent of gene expression; hypermethylation of genes was found to be 71% at 10 days, 68% at 35 days, and 91% at 10 + 25 days washout. Differential gene expression paralleled DNA methylation in 22% of genes at 10-day treatment, 17% at 35 days, and 48% at 10 + 25 days washout. We show here that MDMA induced cardiac epigenetic changes in DNA methylation where hypermethylation predominated. Moreover, MDMA induced gene expression of key elements of circadian rhythm regulatory genes. This suggests a fundamental organism-level event to explain some of the etiologies of MDMA dysfunction in the heart. PMID:26251327

  4. Effects of long-term microgravity exposure in space on circadian rhythms of heart rate variability.

    PubMed

    Yamamoto, Naomune; Otsuka, Kuniaki; Kubo, Yutaka; Hayashi, Mitsutoshi; Mizuno, Koh; Ohshima, Hiroshi; Mukai, Chiaki

    2015-04-01

    We evaluated their circadian rhythms using data from electrocardiographic records and examined the change in circadian period related to normal RR intervals for astronauts who completed a long-term (≥6-month) mission in space. The examinees were seven astronauts, five men and two women, from 2009 to 2010. Their mean ± SD age was 52.0 ± 4.2 years (47-59 yr). Each stayed in space for more than 160 days; their average length of stay was 172.6 ± 14.6 days (163-199 days). We conducted a 24-h Holter electrocardiography before launch (Pre), at one month after launch (DF1), at two months after launch (DF2), at two weeks before return (DF3), and at three months after landing (Post), comparing each index of frequency-domain analysis and 24-h biological rhythms of the NN intervals (normal RR intervals). Results show that the mean period of Normal Sinus (NN) intervals was within 24 ± 4 h at each examination. Inter-individual variability differed among the stages, being significantly smaller at DF3 (Pre versus DF1 versus DF3 versus Post = 22.36 ± 2.50 versus 25.46 ± 4.37 versus 22.46 ± 1.75 versus 26.16 ± 7.18 h, p < 0.0001). The HF component increased in 2 of 7 astronauts, whereas it decreased in 3 of 7 astronauts and 1 was remained almost unchanged at DF1. During DF3, about 6 months after their stay in space, the HF component of 5 of 7 astronauts recovered from the decrease after launch, with prominent improvement to over 20% in 3 astronauts. Although autonomic nervous functions and circadian rhythms were disturbed until one month had passed in space, well-scheduled sleep and wake rhythms and meal times served as synchronizers. PMID:25392280

  5. Alterations of the intercellular coupling protein, connexin-43, during ventricular fibrillation and sinus rhythm restoration demonstrated in male and female rat hearts: A pilot study

    PubMed Central

    Radošinská, Jana; Knezl, Vladimír; Benová, Tamara; Urban, L’ubomír; Tribulová, Narcis; Slezák, Ján

    2011-01-01

    Ventricular fibrillation (VF) is a life-threatening arrhythmia, whose occurrence precedes the development of myocardial arrhythmogenic substrate resulting from either chronic or acute pathophysiological conditions. The authors’ previous and current studies suggest that downregulated and/or heterogeneously distributed cell-to-cell coupling protein – connexin-43 (Cx43) – facilitates the development of malignant arrhythmias. It was hypothesized that VF itself deteriorates Cx43, and may hamper cardioversion into sinus rhythm. The purpose of the present study was to examine whether myocardial expression and the phosphorylated status of Cx43 is altered due to VF and during sinus rhythm restoration. Experiments were performed using 10-month-old male and female Wistar rats. Isolated Langendorff-mode-perfused rat hearts were subjected to the following events: basal condition, electrically induced VF lasting 2 min, electrically induced VF lasting 10 min, and sustained VF followed by spontaneous sinus rhythm restoration due to transient stop perfusion. The hearts were snap frozen at each event; ventricular tissue was sent for Cx43 immunoblotting using rabbit antiCx43 polyclonal antibody to detect phosphorylated (P-Cx43) as well as unphosphorylated (noP-Cx43) forms of Cx43, and mouse antiCx43 monoclonal antibody to detect noP-Cx43 only. Compared with basal conditions, total Cx43 expression did not change during experiments in either male or female rat hearts. However, P-Cx43 and the ratio of P-Cx43 to total Cx43 decreased significantly due to VF lasting 2 min and 10 min in male rat hearts only. In parallel, there was a significant increase in noP-Cx43 due to VF lasting 2 min and 10 min in male rat hearts only. Surprisingly, an enhancement of noP-Cx43 linked with suppression of P-Cx43 was detected during stop perfusion-induced termination of VF lasting 2 min, followed by sinus rhythm restoration in both male and female rat hearts. Sinus rhythm was not restored after 10

  6. Alterations of the intercellular coupling protein, connexin-43, during ventricular fibrillation and sinus rhythm restoration demonstrated in male and female rat hearts: A pilot study.

    PubMed

    Radošinská, Jana; Knezl, Vladimír; Benová, Tamara; Urban, L'ubomír; Tribulová, Narcis; Slezák, Ján

    2011-01-01

    Ventricular fibrillation (VF) is a life-threatening arrhythmia, whose occurrence precedes the development of myocardial arrhythmogenic substrate resulting from either chronic or acute pathophysiological conditions. The authors' previous and current studies suggest that downregulated and/or heterogeneously distributed cell-to-cell coupling protein - connexin-43 (Cx43) - facilitates the development of malignant arrhythmias. It was hypothesized that VF itself deteriorates Cx43, and may hamper cardioversion into sinus rhythm. The purpose of the present study was to examine whether myocardial expression and the phosphorylated status of Cx43 is altered due to VF and during sinus rhythm restoration. Experiments were performed using 10-month-old male and female Wistar rats. Isolated Langendorff-mode-perfused rat hearts were subjected to the following events: basal condition, electrically induced VF lasting 2 min, electrically induced VF lasting 10 min, and sustained VF followed by spontaneous sinus rhythm restoration due to transient stop perfusion. The hearts were snap frozen at each event; ventricular tissue was sent for Cx43 immunoblotting using rabbit antiCx43 polyclonal antibody to detect phosphorylated (P-Cx43) as well as unphosphorylated (noP-Cx43) forms of Cx43, and mouse antiCx43 monoclonal antibody to detect noP-Cx43 only. Compared with basal conditions, total Cx43 expression did not change during experiments in either male or female rat hearts. However, P-Cx43 and the ratio of P-Cx43 to total Cx43 decreased significantly due to VF lasting 2 min and 10 min in male rat hearts only. In parallel, there was a significant increase in noP-Cx43 due to VF lasting 2 min and 10 min in male rat hearts only. Surprisingly, an enhancement of noP-Cx43 linked with suppression of P-Cx43 was detected during stop perfusion-induced termination of VF lasting 2 min, followed by sinus rhythm restoration in both male and female rat hearts. Sinus rhythm was not restored after 10 min of

  7. [The dependence of the heart rhythm on anxiousness as a stable individual characteristic].

    PubMed

    Danilova, N N; Korshunova, S G; Sokolov, E N; Chernyshenko, E N

    1995-01-01

    In 90 subjects (25 males and 65 females) aged 17-19 heart and respiration rates were telemetrically recorded with a "Sport" polygraph under conditions of rest and arithmetical load (periods of 3 min each). Spectral analysis of heart rate and respiration and statistical processing was performed off-line by an IBM PC XT with the software package PFE2. Anxiety was tested according to Spielberger State-Trait-Anxiety Inventory with Hanin modification and strength of excitation and inhibition according to Strelau Temperament Inventory. It was shown that the group characterized by the high trait-anxiety had significantly higher resting heart rate and Baevskiĭ index of strain than the group with low trait-anxiety. The groups differed also in R-R interval variability (standard deviation) under arithmetic load. In the group with high trait-anxiety R-R interval variability was lower than in the other group mainly in two frequency bands of R-R power spectrum, i. e., those of respiratory arrhythmia (RA) and Traube-Hering-Mayer waves (THM). Mental load evoked an increase in the heart rate and Baevskiĭ index and decrease in the power of RA and THM frequency bands. Such peculiarities of the heart rate in both groups during the periods of rest and informational load can be explained in the framework of reciprocal relationship between orienting (lower trait-anxiety, lower heart rate, higher R-R interval variability mainly in RA and THM bands of R-R power spectrum) and defensive reflexes (higher trait-anxiety, higher heart rate, lower R-R interval variability, in particular in RA and THM bands of R-R power spectrum. PMID:8540248

  8. Detection of heart rate and rhythm with a smartphone-based electrocardiograph versus a reference standard electrocardiograph in dogs and cats.

    PubMed

    Kraus, Marc S; Gelzer, Anna R; Rishniw, Mark

    2016-07-15

    OBJECTIVE To evaluate the diagnostic utility of ECGs acquired with a smartphone-based device, compared with reference 6-lead ECGs, for identification of heart rate and rhythm in dogs and cats. DESIGN Prospective study. ANIMALS 51 client-owned dogs and 27 client-owned cats. PROCEDURES Patients examined by a small animal referral cardiology service between April 2012 and January 2013 were enrolled consecutively. In each patient, a 30-second ECG was simultaneously acquired with a smartphone-based device (a bipolar, single-lead recorder coupled to a smartphone with an ECG application) and a standard 6-lead ECG machine. Recordings were evaluated by 3 board-certified cardiologists, and intra- and interobserver agreement were evaluated for both rhythm diagnosis and QRS polarity identification. RESULTS Values for instantaneous and mean heart rates for the smartphone-acquired and reference ECGs were within 1 beat of each other when mean heart rates were calculated. Intraobserver agreement for rhythm assessment was very high, with maximum disagreement for any observer for only 2 of 51 dogs and only 4 of 27 cats. There was minimal disagreement in the polarity of depolarization between the smartphone-acquired and reference ECGs in dogs but frequent disagreement in cats. Interobserver agreement for smartphone-acquired ECGs was similar to that for reference ECGs. with all 3 observers agreeing on the rhythm analysis and minimal disagreement on polarity. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that ECGs acquired with the smartphone-based device accurately identified heart rate and rhythm in dogs and cats. Thus, the device may allow veterinarians to evaluate and manage cardiac arrhythmias relatively inexpensively at the cage side and could also allow clinicians to rapidly share information via email for further consultation, potentially enhancing patient care. PMID:27379594

  9. An exploration of heart rate response to differing music rhythm and tempos.

    PubMed

    da Silva, Ariany G; Guida, Heraldo L; Antônio, Ana Márcia Dos S; Marcomini, Renata S; Fontes, Anne M G G; Carlos de Abreu, Luiz; Roque, Adriano L; Silva, Sidney B; Raimundo, Rodrigo D; Ferreira, Celso; Valenti, Vitor E

    2014-05-01

    The aim of this study was to investigate acute cardiac response and heart rate variability (HRV) when listening to differing forms of music. Eleven healthy men aged between 18 and 25 years old were included in the study. HRV was recorded at rest for ten minutes with no music, then were asked to listen to classical baroque or heavy metal music for a period of 20 min. It was noted that heart rate variability did not affect HRV indices for time and frequency. In conclusion, music with different tempos does not influence cardiac autonomic regulation in men. However more studies are suggested to explore this topic in greater detail. PMID:24767959

  10. The "Heart" of the European "Body Politic". British and German Perspectives on Europe's Central "Organ"

    ERIC Educational Resources Information Center

    Musolff, Andreas

    2004-01-01

    On the basis of a corpus of British and German press coverage of European Union (EU) politics over the 1990s, the paper analyses uses of the geopolitical HEART metaphor. Over the course of the 1990s, successive British governments promised to work "at" the "heart of Europe". However, no one ever claimed that Britain was "in" the heart of Europe,…

  11. Aging and CaMKII alter intracellular Ca2+ transients and heart rhythm in Drosophila melanogaster.

    PubMed

    Santalla, Manuela; Valverde, Carlos A; Harnichar, Ezequiel; Lacunza, Ezequiel; Aguilar-Fuentes, Javier; Mattiazzi, Alicia; Ferrero, Paola

    2014-01-01

    Aging is associated to disrupted contractility and rhythmicity, among other cardiovascular alterations. Drosophila melanogaster shows a pattern of aging similar to human beings and recapitulates the arrhythmogenic conditions found in the human heart. Moreover, the kinase CaMKII has been characterized as an important regulator of heart function and an arrhythmogenic molecule that participate in Ca2+ handling. Using a genetically engineered expressed Ca2+ indicator, we report changes in cardiac Ca2+ handling at two different ages. Aging prolonged relaxation, reduced spontaneous heart rate (HR) and increased the occurrence of arrhythmias, ectopic beats and asystoles. Alignment between Drosophila melanogaster and human CaMKII showed a high degree of conservation and indicates that relevant phosphorylation sites in humans are also present in the fruit fly. Inhibition of CaMKII by KN-93 (CaMKII-specific inhibitor), reduced HR without significant changes in other parameters. By contrast, overexpression of CaMKII increased HR and reduced arrhythmias. Moreover, it increased fluorescence amplitude, maximal rate of rise of fluorescence and reduced time to peak fluorescence. These results suggest that CaMKII in Drosophila melanogaster acts directly on heart function and that increasing CaMKII expression levels could be beneficial to improve contractility. PMID:25003749

  12. Aging and CaMKII Alter Intracellular Ca2+ Transients and Heart Rhythm in Drosophila melanogaster

    PubMed Central

    Santalla, Manuela; Valverde, Carlos A.; Harnichar, Ezequiel; Lacunza, Ezequiel; Aguilar-Fuentes, Javier; Mattiazzi, Alicia; Ferrero, Paola

    2014-01-01

    Aging is associated to disrupted contractility and rhythmicity, among other cardiovascular alterations. Drosophila melanogaster shows a pattern of aging similar to human beings and recapitulates the arrhythmogenic conditions found in the human heart. Moreover, the kinase CaMKII has been characterized as an important regulator of heart function and an arrhythmogenic molecule that participate in Ca2+ handling. Using a genetically engineered expressed Ca2+ indicator, we report changes in cardiac Ca2+ handling at two different ages. Aging prolonged relaxation, reduced spontaneous heart rate (HR) and increased the occurrence of arrhythmias, ectopic beats and asystoles. Alignment between Drosophila melanogaster and human CaMKII showed a high degree of conservation and indicates that relevant phosphorylation sites in humans are also present in the fruit fly. Inhibition of CaMKII by KN-93 (CaMKII-specific inhibitor), reduced HR without significant changes in other parameters. By contrast, overexpression of CaMKII increased HR and reduced arrhythmias. Moreover, it increased fluorescence amplitude, maximal rate of rise of fluorescence and reduced time to peak fluorescence. These results suggest that CaMKII in Drosophila melanogaster acts directly on heart function and that increasing CaMKII expression levels could be beneficial to improve contractility. PMID:25003749

  13. Impact of different colours of artificial light at night on melatonin rhythm and gene expression of gonadotropins in European perch.

    PubMed

    Brüning, Anika; Hölker, Franz; Franke, Steffen; Kleiner, Wibke; Kloas, Werner

    2016-02-01

    The distribution and intensity of artificial light at night, commonly referred to as light pollution, is consequently rising and progressively also ecological implications come to light. Low intensity light is known to suppress nocturnal melatonin production in several fish species. This study aims to examine the least suppressive light colour for melatonin excreted into the holding water and the influence of different light qualities and quantities in the night on gene expression of gonadotropins in fish. European perch (Perca fluviatilis) were exposed to light of different wavelengths during the night (blue, green, and red). Melatonin concentrations were measured from water samples every 3h during a 24h period. Gene expression of gonadotropins was measured in perch exposed to different light colours and was additionally examined for perch subjected to different intensities of white light (0 lx, 1 lx, 10 lx, 100 lx) during the night. All different light colours caused a significant drop of melatonin concentration; however, blue light was least suppressive. Gene expression of gonadotropins was not influenced by nocturnal light of different light colours, but in female perch gonadotropin expression was significantly reduced by white light already at the lowest level (1 lx). We conclude that artificial light with shorter wavelengths at night is less effective in disturbing biological rhythms of perch than longer wavelengths, coinciding with the light situation in freshwater habitats inhabited by perch. Different light colours in the night showed no significant effect on gonadotropin expression, but white light in the night can disturb reproductive traits already at very low light intensities. These findings indicate that light pollution has not only the potential to disturb the melatonin cycle but also the reproductive rhythm and may therefore have implications on whole species communities. PMID:26584071

  14. Noninvasive recovery of epicardial potentials in a realistic heart-torso geometry. Normal sinus rhythm.

    PubMed

    Messinger-Rapport, B J; Rudy, Y

    1990-04-01

    The inverse problem in electrocardiography implies the reconstruction of electrical events within the heart from information measured noninvasively on the body surface. Deduction of these electrical events is possible from measured epicardial potentials, and, thus, a noninvasive method of recovering epicardial potentials from body surface data is useful in experimental and clinical studies. In the present study, an inverse method that uses Tikhonov regularization was shown to reconstruct, with good accuracy, important events in cardiac excitation. The inverse procedure was employed on data obtained from a human-torso tank in which a beating canine heart was placed in the correct anatomical position. Comparison with the actual, measured epicardial potentials indicates that positions and shapes of potential features (maxima, minima, zero potential line, saddles, etc.) are recovered with good accuracy throughout the QRS. An error in position of up to 1 cm is typical, while amplitudes are slightly diminished. In addition, application was extended from the above setting, in which the geometry was precisely known and potentials at a large number of leads were measured accurately, to a situation that is more representative of clinical and experimental settings. Effects of inaccuracy in location of the position of the heart were examined. A stylized torso that approximates the actual geometry was designed, and its performance in the inverse computations was evaluated. A systematic method of reduction of the number of leads on the body surface was proposed, and the resulting lead configurations were evaluated in terms of the accuracy of inverse solutions. The results indicate that the inverse problem can be stabilized with respect to different types of uncertainties in measured data and offer promise in the use of the inverse procedure in clinical and experimental situations. PMID:2317885

  15. Cardiac Rhythm Monitoring After Acute Decompensation for Heart Failure: Results from the CARRYING ON for HF Pilot Study

    PubMed Central

    Mortara, Andrea; Diotallevi, Paolo; Gallone, Giuseppe; Mariconti, Barbara; Gronda, Edoardo; Gentili, Alessandra; Bisetti, Silvia; Botto, Giovanni Luca

    2016-01-01

    Background There’s scarce evidence about cardiovascular events (CV) in patients with hospitalization for acute heart failure (HF) and no indication for immediate device implant. Objective The CARdiac RhYthm monitorING after acute decompensatiON for Heart Failure study was designed to assess the incidence of prespecified clinical and arrhythmic events in this patient population. Methods In this pilot study, 18 patients (12 (67%) male; age 72±10; 16 (89%) NYHA II-III), who were hospitalized for HF with low left ventricular ejection fraction (LVEF) (<40%) and no immediate indication for device implant received an implantable loop recorder (ILR) before hospital discharge. Follow-up visits were scheduled at 3 and 6 months, and at every 6 months until study closure; device data were remotely reviewed monthly. CV mortality, unplanned CV hospitalization, and major arrhythmic events during follow-up were analyzed. Results During a median follow-up of 593 days, major CV occurred in 13 patients (72%); of those, 7 patients had at least 1 cardiac arrhythmic event, 2 had at least a clinical event (CV hospitalization or CV death), and 4 had both an arrhythmic and a CV event. Six (33%) patients experienced 10 major clinical events, 5 of them (50%) were HF related. During follow-up, 2 (11%) patients died due to a CV cause and 3 (16%) patients received a permanent cardiac device. Conclusions After an acute HF hospitalization, patients with LVEF<40% and who are not readily eligible for permanent cardiac device implant have a known high incidence of major CV event. In these patients, ILR allows early detection of major cardiac arrhythmias and the ability to react appropriately in a timely manner. Trial Registration ClinicalTrials.gov NCT01216670; https://clinicaltrials.gov/ct2/show/NCT01216670 PMID:27118481

  16. [HEART RHYTHM VARIABILITY ANALYSIS AND ASSESSMENT OF THE SPINAL PAIN SYNDROME DURING DRY IMMERSION].

    PubMed

    Sun, I; Voronkov, Yu I; Ardashev, V N; Glukhova, S I

    2015-01-01

    The spinal pain syndrome appears in cosmonauts on both short and long-duration missions. This untoward factor may affect body systems functioning and complicate the successful accomplishment of space mission. Purpose of the investigation was to examine the lumbar spine and to elucidate whether its condition relates to the spinal pain development and changes in heart rate variability (HRV) in the microgravity environment. The experiment was conducted in dry immersion as a method of microgravity effects simulation. It was shown that in dry immersion locomotion reproduces the patterns peculiar for significant gravitational unloading. Spinal pain intensity, angles and heights of the lumbar intervertebral discs and HRV were measured in 19 selected volunteers. During the experiment, all the volunteers developed pains in the back that abated gradually. Pain dependence on the height of intervertebral discs and cardiac regulatory mechanisms were investigated. PMID:26292423

  17. Development of regulation of the cardiac chronotropic function in albino rats during the early postnatal ontogeny according to the results of spectral analysis of heart rhythm variability.

    PubMed

    Kurjanova, E V; Teplyj, D L; Zereninova, N V

    2012-04-01

    Regulation of the cardiac chronotropic function was studied by spectral analysis of cardiac rhythm variability in HF, LF, and VLF bands in rats at various stages of the early postnatal ontogeny. The inadequacy of the regulatory mechanisms during the first days of life manifested by low power of all waves (particularly HF) in the cardiac rhythm variability spectrum. On day 14 of life, the cardiointerval variability was formed by HF waves, their low power together with increasing heart rate indicating more intense sympathetic effects. On day 21 of life, a potent elevation of the VLF power reflected a stronger centralization of regulation from higher autonomic centers. The age of 28 days was characterized by a sharp increase of HF activity and could be regarded as the turning point in the development of parasympathetic effects and activity of the autonomic regulation contour. From the age of 35 days, the wave power and the proportion of the spectral components of cardiac rhythm variability in albino rats corresponded to the adult pattern; a trend to the central regulation predominance and to greater rigidity of cardiac rhythm formed only with the onset of sexual maturation. PMID:22803162

  18. Circadian Rhythms

    MedlinePlus

    ... chronobiology. Are circadian rhythms the same thing as biological clocks? No, but they are related. Our biological clocks drive our circadian rhythms. What are biological clocks? The biological clocks that control circadian rhythms ...

  19. THE INTRINSIC RHYTHM OF THE TURTLE'S HEART STUDIED WITH A NEW TYPE OF CHRONOGRAPH, TOGETHER WITH THE EFFECTS OF SOME DRUGS AND HORMONES.

    PubMed

    Loomis, A L; Harvey, E N; Macrae, C

    1930-09-20

    A chronograph is described for recording continuously the rates of many different kinds of rhythmic processes over long time periods. The rate is read directly from the length of a line of ink, drawn by a moving pen. Rates of beat of excised turtle's hearts in Ringer's solution have been recorded at 25 degrees C. under constant conditions of temperature, pH, and oxygen supply for periods of 36 hours. Regular periodic variations in the fundamental rhythm are figured, as well as rates of extraordinary constancy. The effects of adrenalin, ephedrin, thyroxin, alpha and beta pituitary hormone insulin, nicotin, and atropin are described in the text. PMID:19872568

  20. EACVI appropriateness criteria for the use of cardiovascular imaging in heart failure derived from European National Imaging Societies voting.

    PubMed

    Garbi, Madalina; Edvardsen, Thor; Bax, Jeroen; Petersen, Steffen E; McDonagh, Theresa; Filippatos, Gerasimos; Lancellotti, Patrizio

    2016-07-01

    This paper presents the first European appropriateness criteria for the use of cardiovascular imaging in heart failure, derived from voting of the European National Imaging Societies representatives. The paper describes the development process and discusses the results. PMID:27129538

  1. Oral contraceptives alter circadian rhythm parameters of cortisol, melatonin, blood pressure, heart rate, skin blood flow, transepidermal water loss, and skin amino acids of healthy young women.

    PubMed

    Reinberg, A E; Touitou, Y; Soudant, E; Bernard, D; Bazin, R; Mechkouri, M

    1996-08-01

    Sixteen healthy women users and nonusers of oral contraceptives (OC) volunteered to document a set of circadian rhythms. Nine were taking OC providing ethynyl estradiol (0.03-0.05 mg/24h, 21 days/month) combined with DL- or L-norgestrel or norethisterone. There was no group difference (p > 0.05) in median age (22 years), weight (57 kg), and height (162) cm). Data were obtained at fixed hours, 5 times/24h, during a 48-h span, in November. (Day activity from approximately 08:00 to approximately 23:00 h and night rest). Environmental conditions were controlled, using air-conditioned rooms of constant temperature (26 degrees +/- 0.5) and relative humidity 45% +/- 1. Both cosinor and ANOVA were used for statistical analyses. All circadian rhythms were validated with one exception: that of salivary melatonin was not detected in OC users. The 24h mean (M) exhibited group differences for certain variables: M was greater in OC than non-OC users for systolic blood pressure (p < 0.0001), heart rate (p < 0.01), skin blood flow (p < 0.04), and transepidermal water loss (p < 0.02). M was lower in OC than non-OC users in salivary cortisol (p < 0.04) and skin amino acids (p < 0.003). No group difference was detected in any other documented rhythms: diastolic blood pressure, grip strength of both hands, oral temperature, self-rated fatigue, and the skin variables of urea, lactate, triglycerides, and acid phosphatase activity. PMID:8874983

  2. Assessment of Time and Frequency Domain Parameters of Heart Rate Variability and Interictal Cardiac Rhythm Abnormalities in Drug-naïve Patients with Idiopathic Generalized Epilepsy

    PubMed Central

    Kilinc, Ozden; Cincin, Altug; Pehlivan, Aslihan; Midi, Ipek; Kepez, Alper; Agan, Kadriye

    2016-01-01

    Background and Purpose: Epilepsy is a disease known to occur with autonomous phenomenons. Earlier studies indicate decreased heart rate variability (HRV) during ictal and interictal periods among epilepsy patients. In this study, we aim to investigate cardiac rhythm abnormalities and HRV during interictal period between drug-naïve patients with idiopathic generalized epilepsy (IGE) and healthy control group. Methods: Twenty-six patients with IGE and 26 healthy individuals included in the study. In order to eliminate any structural cardiac pathology, transthoracic echocardiography was performed in all subjects and time and frequency domain parameters of HRV were evaluated after 24-hour rhythm holter monitoring. Results: Between two groups, no significant difference was detected in terms of mean heart rate and maximum duration between the start of the Q waves and the end of the T waves (QT intervals). In the time domain analysis of HRV, no statically significant difference was detected for standard deviation of all R - R intervals and root-mean-square of successive differences between patient and control group (p = 0,070 and p = 0,104 respectively). In the frequency domain analysis of HRV, patients tended to display lower total power and very low frequency power than did healthy subjects, but the differences were not statistically significant. Conclusions: Our results suggest that there is no major effect of the epilepsy on HRV in patients with IGE. It should be emphasized that, in this study, HRV was evaluated only in patients with IGE and that the results are not proper to be generalized for patients with partial seizures. PMID:27390676

  3. Synchronization by low-amplitude light-dark cycles of 24-hour pineal and plasma melatonin rhythms of hatchling European starlings (Sturnus vulgaris).

    PubMed

    Gwinner, E; Zeman, M; Klaassen, M

    1997-11-01

    In young European starlings, as in other avian species, high-amplitude 24-hr rhythms in plasma and pineal melatonin are already present around the time of hatching. In chickens this rhythmicity results at least partly from the light sensitivity of the melatonin-producing and -secreting system. In contrast to the chicken, the starling is a hole-nesting bird, and it seemed questionable whether the low light intensities in the nest are sufficient to synchronize perinatal melatonin rhythms. We therefore exposed starling eggs to light cycles roughly simulating those measured in nest-boxes, i.e., an 11-hr phase of complete darkness and a 13-hr phase consisting of 15 min of dim light (10 lux) alternating with 30 min of darkness. For one group the photophase lasted from 0600 to 1900 hr; for the other group the photophase lasted from 1800 to 0700 hr. In approximately 10-hr-old hatchlings of both groups, plasma and pineal melatonin concentrations were high during the dark phase and low during the light phase. We conclude that perinatal low-amplitude light intensity changes of the kind experienced by hatching starlings in the field are sufficient for synchronizing the melatonin-producing and -secreting system in the pineal and possibly other organs. PMID:9462849

  4. Heart palpitations

    MedlinePlus

    Heart palpitations can be due to: Anxiety, stress, panic attack, or fear Caffeine intake Nicotine intake Cocaine or other illegal drugs Diet pills Exercise Fever However, some palpitations are due to an abnormal heart rhythm, ...

  5. Pharmacodynamics of beta-blockers in heart failure: lessons from the carvedilol or metoprolol European trial.

    PubMed

    Bauman, Jerry L; Talbert, Robert L

    2004-06-01

    Heart failure is a growing public health problem in the United States, and the approach to the treatment of heart failure has undergone a radical transformation in the past decade. The use of beta-blocker therapy in heart failure patients is now widely recommended, based on evidence from large-scale clinical trials demonstrating that bisoprolol, carvedilol, and extended-release metoprolol succinate significantly reduce morbidity and mortality in patients with heart failure. Although these agents appear to provide similar benefits, the question remains whether pharmacologic differences among them could translate to differences in clinical outcomes. The Carvedilol Or Metoprolol European Trial (COMET) compared nonselective blockade of the beta1-/beta2-/alpha1-adrenergic receptors with carvedilol versus selective beta1-blockade with immediate-release metoprolol tartrate in patients with chronic heart failure. The trial found that carvedilol significantly reduced all-cause mortality compared with immediate-release metoprolol tartrate, although there were no differences in hospitalizations. Herein we review the pharmacokinetics and pharmacodynamics of metoprolol and carvedilol. In doing so, several issues regarding the design of COMET are identified that could alter the interpretation of the results of this trial. These include the choice of dose and dosage regimen of immediate-release metoprolol tartrate, a dosage form that has never been shown to reduce mortality in patients with heart failure. Additional studies are needed to fully understand whether there are any advantages of selective versus nonselective adrenergic blockade and whether there are any clinically meaningful differences in effectiveness between beta-blockers with proven benefit in the management of chronic heart failure. The results of COMET demonstrate that all beta-blockers and dosage forms are not interchangeable when prescribed for heart failure. Clinicians should choose only those agents (and

  6. Outcome of patients with right heart thrombi: the Right Heart Thrombi European Registry.

    PubMed

    Koć, Marcin; Kostrubiec, Maciej; Elikowski, Waldemar; Meneveau, Nicolas; Lankeit, Mareike; Grifoni, Stefano; Kuch-Wocial, Agnieszka; Petris, Antoniu; Zaborska, Beata; Stefanović, Branislav S; Hugues, Thomas; Torbicki, Adam; Konstantinides, Stavros; Pruszczyk, Piotr

    2016-03-01

    Our aim was the assessment of the prognostic significance of right heart thrombi (RiHT) and their characteristics in pulmonary embolism in relation to established prognostic factors.138 patients (69 females) aged (mean±sd) 62±19 years with RiHT were included into a multicenter registry. A control group of 276 patients without RiHT was created by propensity scoring from a cohort of 963 contemporary patients. The primary end-point was 30-day pulmonary embolism-related mortality; the secondary end-point included 30-day all-cause mortality. In RiHT patients, pulmonary embolism mortality was higher in 31 patients with systolic blood pressure <90 mmHg than in 107 normotensives (42% versus 12%, p=0.0002) and was higher in the 83 normotensives with right ventricular dysfunction (RVD) than in the 24 normotensives without RVD (16% versus 0%, p=0.038). In multivariable analysis the simplified Pulmonary Embolism Severity Index predicted mortality (hazard ratio 2.43, 95% CI 1.58-3.73; p<0.0001), while RiHT characteristics did not. Patients with RiHT had higher pulmonary embolism mortality than controls (19% versus 8%, p=0.003), especially normotensive patients with RVD (16% versus 7%, p=0.02).30-day mortality in patients with RiHT is related to haemodynamic consequences of pulmonary embolism and not to RiHT characteristics. However, patients with RiHT and pulmonary embolism resulting in RVD seem to have worse prognosis than propensity score-matched controls. PMID:26797032

  7. [Gender differences of the influence of an "aggressive" computer game on the variability of the heart rhythm].

    PubMed

    Stepanian, L S; Grigorian, V G; Stepanian, A Iu

    2010-01-01

    The influence of virtual aggressogenic environment on psychoemotional sphere of male and female teenagers with different levels of personal aggression was studied by characteristics of the heart rate. The exposure to the aggressogenic factors produced a change of the centralized control for the autonomic control in female and male teenagers with the high level of aggression and females with the low level of aggression. Male teenagers with the low level of aggression displayed the prevalence of the centralized control. Thus, the influence of exposure of teenagers to the virtual aggressogenic environment was shown to be ambiguous depending on the level of the level of personal aggression and gender. PMID:20469589

  8. Carvedilol in the treatment of chronic heart failure: lessons from the Carvedilol Or Metoprolol European Trial.

    PubMed

    Kveiborg, Britt; Major-Petersen, Atheline; Christiansen, Buris; Torp-Pedersen, Christian

    2007-01-01

    Beta-blockers have been shown to improve survival in patients with chronic heart failure. The effect of different generations of beta blockers has been debated. Both metoprolol and carvedilol have demonstrated beneficial effects in placebo-controlled trials. In The Carvedilol Or Metoprolol European Trial (COMET) two beta blockers were compared in a double-blind randomized matter. This is the first direct comparison between metoprolol and carvedilol of long-term effect on survival in patients with chronic heart failure. The all-cause mortality was significantly reduced in the favour of carvedilol. The dose and formulation of metoprolol used in this trial has caused debate, and it has been questioned whether a similar beta1-blockade is obtained in the two intervention groups. At this time there is an unresolved debate as to whether carvedilol is a superior beta-blocker or whether differences in beta1-blockade explained the results of COMET. PMID:17583173

  9. [Autonomic regulation in patients with panic attacks based on longitudinal study data on the variability of the heart rhythm].

    PubMed

    Khaspekova, N B; Diukova, G M; Tumalaeva, Z N; Alieva, Kh K

    1999-01-01

    During a repeated study in recumbent position as well as during 48-hour monitoring of the indices of variability of RR intervals of ECG (MDRR) in patients with panic attacks (PA) a stable dominance of VLF (0.07-0.01 Hz) and rigidity of the spectrum typical for patients with panic attacks (PA) in period between the attacks was found. Prevalence of fear emotions as well as accompanying hypothalamic insufficiency were also associated with a decrease of HF. In prodromic period, in attack and after it, there was no dynamics in the frequency of heart's contractions, but there was a sharp increase of MDRR. In prodromic period VLF and LF considerably increased, while HF decreased. In a moment of a panic attack LF and HF continued to increase, while VLF significantly lowered. Activation of vasomotor (LF), vagal (HF) and cerebral (VLF) mechanisms was maintained during 5 minutes of the study after PA completion with a clear predominance of LF component. PMID:10441851

  10. Effects of music composed by Mozart and Ligeti on blood pressure and heart rate circadian rhythms in normotensive and hypertensive rats.

    PubMed

    Lemmer, Björn

    2008-11-01

    There is continuing discussion on the effect of music ("Mozart effect") on numerous functions in man and experimental animals. Radiotelemetry now allows one to monitor cardiovascular functions in freely-moving unrestrained experimental animals. Radiotelemetry was used to monitor systolic and diastolic blood pressure (SBP, DBP), heart rate (HR), and motor activity (MA) in male normotensive WKY and hypertensive SHR animals. Rats were synchronized to a 12 h light (L): 12 h dark (D) regimen in an isolated, ventilated, light-controlled, sound-isolated animal container. Music (Mozart, Symphony # 40; Ligeti, String Quartet # 2) were played for 2 h at 75 dB in the animal cabin starting at the onset of L or D in a cross-over design. Data were collected every 5 min for 24 h under control conditions and during and after music. In addition, plasma concentrations of norepinephrine (NE) were determined in unrestrained animals at 3 h intervals over 24 h. In both WKY and SHR, highly significant circadian rhythms were obtained in SBP, DBP, HR, and MA under control conditions; HR was lower and BP higher in SHR than in WKY. NE was circadian rhythmic in both strains with higher values in D; the increase in NE with immobilization was much more pronounced in SHR than in WKY. The music of Mozart had no effect on either parameter in WKY, neither in L nor in D. In contrast, in SHR, the music of Mozart presented in L significantly decreased HR and left BP unaffected, leading to a small decrease in cardiac output. The music of Ligeti significantly increased BP both in L and in D and reflexively reduced HR in L, the effects being long-lasting over 24 h. Interestingly, white noise at 75 dB had no effect at all on either function in both strains. The effects of both Mozart and Ligeti cannot be attributed to a stress reaction, as stress due to cage switch increased HR and BP both in WKY and SHR. The study clearly demonstrates that music of different character (tempo, rhythm, pitch, tonality) can

  11. Diurnal 24-hour rhythm in ambulatory heart rate variability during the day shift in rotating shift workers.

    PubMed

    Yoshizaki, Takahiro; Kawano, Yukari; Tada, Yuki; Hida, Azumi; Midorikawa, Toru; Hasegawa, Kohe; Mitani, Takeshi; Komatsu, Taiki; Togo, Fumiharu

    2013-06-01

    Circadian variation in cardiac autonomic nervous system activity and behavior during the day shifts of shift workers has not hitherto been clarified. This study examined diurnal 24-h variation in heart rate variability (HRV), sleep-wake cycle, physical activity, and food intake during the day shift in rotating shift workers. The subjects were female nurses and caregivers working at a health care facility (14 day workers and 13 rotating shift workers). Each subject was asked to undergo 24-h electrocardiograph and step count recordings. Coarse graining spectral analysis was used for approximately 10-min segments of HRV (600 beats) to derive the total power (TOT: >0.04 Hz), integrated power in the low-frequency (LF: 0.04-0.15 Hz) and high-frequency (HF: >0.15 Hz) ranges, the ratio of HF power to TOT (HF nu), and the ratio of LF power to HF power (LF/HF). Double cosinor analysis was used to obtain 24-h and 12-h period variations in variables of HRV and physical activity. While no difference was found in the acrophases of either period for step counts or in the 12-h period of HRV variables between the groups, the acrophases of the 24-h period for HRV variables were delayed by 1.3 to 5.5 h in rotating shift workers, and their differences in HF power, HF nu, and LF/HF reached a significant level (p < 0.05). On the days of the experiment, retiring time, waking up time, total time in bed, sleep efficiency, and mealtimes and energy intake for each diet did not differ between the groups. These results suggest that there is a possibility of an abnormal phase angle between circadian variation in cardiac autonomic nervous system activity and the sleep-wake cycle during the day shift in shift workers. PMID:23735502

  12. Quality of Anticoagulation Control in Preventing Adverse Events in Heart Failure Patients in Sinus Rhythm: A Warfarin Aspirin Reduced Cardiac Ejection Fraction Trial (WARCEF) Substudy

    PubMed Central

    Homma, Shunichi; Thompson, John L.P.; Qian, Min; Ye, Siqin; Di Tullio, Marco R.; Lip, Gregory Y.H.; Mann, Douglas L.; Sacco, Ralph L.; Levin, Bruce; Pullicino, Patrick M.; Freudenberger, Ronald S.; Teerlink, John R.; Graham, Susan; Mohr, J.P.; Labovitz, Arthur J.; Buchsbaum, Richard; Estol, Conrado J.; Lok, Dirk J.; Ponikowski, Piotr; Anker, Stefan D.

    2015-01-01

    Background The aim of this study is to examine the relationship between time in therapeutic range (TTR) and clinical outcomes in heart failure (HF) patients in sinus rhythm (SR) treated with warfarin. Methods and Results We used data from the Warfarin vs. Aspirin in Reduced Cardiac Ejection Fraction Trial (WARCEF) to assess the relationship of TTR with the WARCEF primary outcome (ischemic stroke, intracerebral hemorrhage, or death); with death alone; ischemic stroke alone; major hemorrhage alone; and net clinical benefit (primary outcome and major hemorrhage combined). Multivariable Cox models were used to examine how the event risk changed with TTR and to compare the high TTR, low TTR, and aspirin patients, with TTR being treated as a time-dependent covariate. 2,217 patients were included in the analyses, among whom 1,067 were randomized to warfarin and 1,150 were randomized to aspirin. The median (IQR) follow-up duration was 3.6 (2.0–5.0) years. Mean (±SD) age was 61±11.3 years, with 80% being men. The mean (±SD) TTR was 57% (±28.5%). Increasing TTR was significantly associated with reduction in primary outcome (adjusted p<0.001), death alone (adjusted p=0.001), and improved net clinical benefit (adjusted p<0.001). A similar trend was observed for the other two outcomes but significance was not reached (adjusted p=0.082 for ischemic stroke, adjusted p=0.109 for major hemorrhage). Conclusions In HF patients in SR, increasing TTR is associated with better outcome and improved net clinical benefit. Patients in whom good quality anticoagulation can be achieved may benefit from the use of anticoagulants. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT00041938. PMID:25850425

  13. Associations between Diurnal 24-Hour Rhythm in Ambulatory Heart Rate Variability and the Timing and Amount of Meals during the Day Shift in Rotating Shift Workers

    PubMed Central

    Yoshizaki, Takahiro; Midorikawa, Toru; Hasegawa, Kohe; Mitani, Takeshi; Komatsu, Taiki; Togo, Fumiharu

    2014-01-01

    It has not hitherto been clarified whether there is an association between dietary behavior and circadian variation in autonomic nervous system activity among shift workers. This study examines diurnal 24-h rhythm in heart rate variability (HRV) and dietary behavior among rotating shift workers, while taking into account the sleep-wake cycle and physical activity. The subjects were 11 female and 2 male nurses or caregivers working in a rotating 2-shift system at a health care facility. All the subjects were asked to undergo 24-h electrocardiograph and step count recordings, and to record the time of each meal and the amounts of each food and beverage consumed. Coarse graining spectral analysis was used for approximately 10-min segments of HRV to derive the total power (TOT: >0.04 Hz) of the periodic components and the integrated power of periodic components in the low-frequency (LF: 0.04–0.15 Hz) and high-frequency (HF: >0.15 Hz) ranges. Then the ratio of HF power to TOT (HF nu) and the ratio of LF power to HF power (LF/HF) were calculated to assess cardiac vagal tone and cardiac sympathovagal balance, respectively. Single cosinor analysis was used to obtain 24-h period variations in both variables of HRV. Acrophases of HF nu and LF/HF expressed in time since awakening were significantly (p<0.05) delayed for subjects having breakfast at a later time after awakening. Multivariable regression analysis indicated that the timing of breakfast, the ratio of energy intake at dinner to total energy intake, and total energy intake were correlated to the acrophases of HF nu and/or LF/HF. These results suggest that the phase angle between circadian variation in cardiac autonomic nervous system activity and the sleep-wake cycle may be associated with dietary behavior in shift workers. PMID:25211024

  14. NEUROSENSORY LINKS BETWEEN BRONCHOCONSTRICTION AND CARDIAC RHYTHM

    EPA Science Inventory

    Reports in the literature have attributed altered heart rate, heart rate variability, and rhythm to inhaled particulate matter (PM) in humans. Whereas the changes in heart rate are very small, analysis of ECG tracings indicate changes in HRV suggesting altered autonomic balance. ...

  15. Joint statement of the European Association for the Study of Obesity and the European Society of Hypertension: obesity and heart failure.

    PubMed

    Jordan, Jens; Toplak, Hermann; Grassi, Guido; Yumuk, Volkan; Kotsis, Vasilios; Engeli, Stefan; Cuspidi, Cesare; Nilsson, Peter M; Finer, Nick; Doehner, Wolfram

    2016-09-01

    Obese individuals are more likely to develop heart failure. Yet, once heart failure is established, the impact of overweight and obesity on prognosis and survival is unclear. The purpose of this joint scientific statement of the European Association for the Study of Obesity and the European Society of Hypertension is to provide an overview on the current scientific literature on obesity and heart failure in terms of prognosis, mechanisms, and clinical management implications. Moreover, the document identifies open questions that ought to be addressed. The need for more tailored weight management recommendations in heart failure will be emphasized and, in line with the emerging evidence, aims to distinguish between primary disease and secondary outcome prevention. In the primary prevention of heart failure, it appears prudent advising obese individuals to lose or achieve a healthy body weight, especially in those with risk factors such as hypertension or type 2 diabetes. However, there is no evidence from clinical trials to guide weight management in overweight or obese patients with established heart failure. Prospective clinical trials are strongly encouraged. PMID:27488547

  16. [Wenckebach and his rhythm].

    PubMed

    van Gijn, Jan; Gijselhart, Joost P

    2011-01-01

    Karel Frederik Wenckebach (1864-1940) showed an aptitude for research even as a medical student in Utrecht. After graduation and a thesis on the bursa of Fabricius he worked as an assistant in the physiological laboratory. Following a stint as general practitioner in a mining community (1891-1896) he returned to Utrecht, where he could combine his practice with physiological studies, especially disturbances of the heart rhythm. In 1899, with no other recording instruments than a sphygmomanometer for tracing the radial pulse and a tuning fork for chronometry, he described the 'rhythmic arrhythmia' phenomenon: a missed beat after a given number of regular beats (mostly between three and six), followed by an intermission shorter than the interval between two regular beats. The Wenckebach rhythm is now also known as type I second-degree atrioventricular block. Wenckebach subsequently became a professor of medicine in Groningen (1901), Strasbourg (1911) and Vienna (1914-1929). PMID:22085509

  17. Learning Rhythms.

    ERIC Educational Resources Information Center

    Lippitt, Gordon L.

    1979-01-01

    Discusses factors which determine the quality of learning experiences. The author hypothesizes that there are learning rhythms which must be present in a balanced way for a Peak Learning Experience (PLE) to occur. Learner readiness can be stimulated by a teacher, increasing chances for a PLE. (JOW)

  18. Circadian rhythms in Macaca mulatta monkeys during Bion 11 flight

    NASA Technical Reports Server (NTRS)

    Alpatov, A. M.; Hoban-Higgins, T. M.; Klimovitsky, V. Y.; Tumurova, E. G.; Fuller, C. A.

    2000-01-01

    Circadian rhythms of primate brain temperature, head and ankle skin temperature, motor activity, and heart rate were studied during spaceflight and on the ground. In space, the circadian rhythms of all the parameters were synchronized with diurnal Zeitgebers. However, in space the brain temperature rhythm showed a significantly more delayed phase angle, which may be ascribed to an increase of the endogenous circadian period.

  19. Clinical trials update from the European Society of Cardiology Heart Failure meeting: COMET, COMPANION, Tezosentan and SHAPE.

    PubMed

    Coletta, Alison P; Clark, Andrew L; Seymour, Anne Marie L; Cleland, John G F

    2003-08-01

    This article continues a series of reports on recent research developments in the field of heart failure. Key presentations made at the European Society of Cardiology Heart Failure Update meeting, held in Strasbourg, France are described. The COMET study showed a 17% relative risk reduction in all-cause mortality with carvedilol compared with metoprolol tartrate. The COMPANION study, as previously reported, showed encouraging results for the use of cardiac resynchronisation and implantable defibrillator therapy in patients with heart failure, but further evidence is awaited. The results of a study on tezosentan suggest that lower doses of this endothelin antagonist may be clinically more effective with fewer adverse effects compared with higher doses. The SHAPE survey of heart failure awareness in Europe identified a need for further heart failure education amongst the public, patients, their carers and primary care physicians. PMID:12921817

  20. Rhythm control in atrial fibrillation.

    PubMed

    Piccini, Jonathan P; Fauchier, Laurent

    2016-08-20

    Many patients with atrial fibrillation have substantial symptoms despite ventricular rate control and require restoration of sinus rhythm to improve their quality of life. Acute restoration (ie, cardioversion) and maintenance of sinus rhythm in patients with atrial fibrillation are referred to as rhythm control. The decision to pursue rhythm control is based on symptoms, the type of atrial fibrillation (paroxysmal, persistent, or long-standing persistent), patient comorbidities, general health status, and anticoagulation status. Many patients have recurrent atrial fibrillation and require further intervention to maintain long term sinus rhythm. Antiarrhythmic drug therapy is generally recommended as a first-line therapy and drug selection is on the basis of the presence or absence of structural heart disease or heart failure, electrocardiographical variables, renal function, and other comorbidities. In patients who continue to have recurrent atrial fibrillation despite medical therapy, catheter ablation has been shown to substantially reduce recurrent atrial fibrillation, decrease symptoms, and improve quality of life, although recurrence is common despite continued advancement in ablation techniques. PMID:27560278

  1. Associations of adiponectin with individual European ancestry in African Americans: the Jackson Heart Study

    PubMed Central

    Bidulescu, Aurelian; Choudhry, Shweta; Musani, Solomon K.; Buxbaum, Sarah G.; Liu, Jiankang; Rotimi, Charles N.; Wilson, James G.; Taylor, Herman A.; Gibbons, Gary H.

    2014-01-01

    Background: Compared with European Americans, African Americans (AAs) exhibit lower levels of the cardio-metabolically protective adiponectin even after accounting for adiposity measures. Because few studies have examined in AA the association between adiponectin and genetic admixture, a dense panel of ancestry informative markers (AIMs) was used to estimate the individual proportions of European ancestry (PEA) for the AAs enrolled in a large community-based cohort, the Jackson Heart Study (JHS). We tested the hypothesis that plasma adiponectin and PEA are directly associated and assessed the interaction with a series of cardio-metabolic risk factors. Methods: Plasma specimens from 1439 JHS participants were analyzed by ELISA for adiponectin levels. Using pseudo-ancestral population genotype data from the HapMap Consortium, PEA was estimated with a panel of up to 1447 genome-wide preselected AIMs by a maximum likelihood approach. Interaction assessment, stepwise linear and cubic multivariable-adjusted regression models were used to analyze the cross-sectional association between adiponectin and PEA. Results: Among the study participants (62% women; mean age 48 ± 12 years), the median (interquartile range) of PEA was 15.8 (9.3)%. Body mass index (BMI) (p = 0.04) and insulin resistance (p = 0.0001) modified the association between adiponectin and PEA. Adiponectin was directly and linearly associated with PEA (β = 0.62 ± 0.28, p = 0.03) among non-obese (n = 673) and insulin sensitive participants (n = 1141; β = 0.74 ± 0.23, p = 0.001), but not among those obese or with insulin resistance. No threshold point effect was detected for non-obese participants. Conclusions: In a large AA population, the individual proportion of European ancestry was linearly and directly associated with plasma adiponectin among non-obese and non insulin-resistant participants, pointing to the interaction of genetic and metabolic factors influencing adiponectin levels. PMID:24575123

  2. Bleeding Risk and Antithrombotic Strategy in Patients With Sinus Rhythm and Heart Failure With Reduced Ejection Fraction Treated With Warfarin or Aspirin.

    PubMed

    Ye, Siqin; Cheng, Bin; Lip, Gregory Y H; Buchsbaum, Richard; Sacco, Ralph L; Levin, Bruce; Di Tullio, Marco R; Qian, Min; Mann, Douglas L; Pullicino, Patrick M; Freudenberger, Ronald S; Teerlink, John R; Mohr, J P; Graham, Susan; Labovitz, Arthur J; Estol, Conrado J; Lok, Dirk J; Ponikowski, Piotr; Anker, Stefan D; Thompson, John L P; Homma, Shunichi

    2015-09-15

    We sought to assess the performance of existing bleeding risk scores, such as the Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol Concomitantly (HAS-BLED) score or the Outpatient Bleeding Risk Index (OBRI), in patients with heart failure with reduced ejection fraction (HFrEF) in sinus rhythm (SR) treated with warfarin or aspirin. We calculated HAS-BLED and OBRI risk scores for 2,305 patients with HFrEF in SR enrolled in the Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction trial. Proportional hazards models were used to test whether each score predicted major bleeding, and comparison of different risk scores was performed using Harell C-statistic and net reclassification improvement index. For the warfarin arm, both scores predicted bleeding risk, with OBRI having significantly greater C-statistic (0.72 vs 0.61; p = 0.03) compared to HAS-BLED, although the net reclassification improvement for comparing OBRI to HAS-BLED was not significant (0.32, 95% confidence interval [CI] -0.18 to 0.37). Performance of the OBRI and HAS-BLED risk scores was similar for the aspirin arm. For participants with OBRI scores of 0 to 1, warfarin compared with aspirin reduced ischemic stroke (hazard ratio [HR] 0.51, 95% CI 0.26 to 0.98, p = 0.042) without significantly increasing major bleeding (HR 1.24, 95% CI 0.66 to 2.30, p = 0.51). For those with OBRI score of ≥2, there was a trend for reduced ischemic stroke with warfarin compared to aspirin (HR 0.56, 95% CI 0.27 to 1.15, p = 0.12), but major bleeding was increased (HR 4.04, 95% CI 1.99 to 8.22, p <0.001). In conclusion, existing bleeding risk scores can identify bleeding risk in patients with HFrEF in SR and could be tested for potentially identifying patients with a favorable risk/benefit profile for antithrombotic therapy with warfarin. PMID:26189039

  3. The european multifactorial preventive trial of coronary heart disease: four-year experience.

    PubMed

    Menotti, A

    1983-01-01

    The European Multifactorial Preventive Trial of Coronary Heart Disease operates in five centers in Belgium, Italy, Poland, Spain, and Great Britain with a total of 44 pairs of factories employing over 63,000 men aged 40-59. Pairs of factories were randomly allocated to either treatment or control. An entry screening for risk factors was offered to all men in treatment factories and to random samples of men in control factories. Those identified as relatively high-risk in treatment factories (upper 15-20%) were individually treated with advice for cholesterol lowering diet, smoking cessation, regular exercise, weight reduction, and drug control of hypertension, whereas mass education on the same subjects was given to non-high-risk individuals. Random samples of men were reexamined after 2 and 4 years in order to assess risk factor changes, with control groups serving as reference for naturally occurring trends. Changes of main risk factors recorded in different centers varied considerably. Pooled data showed a net reduction of 2.5% random sample (RS) and 5.8% high-risk (HR) for serum cholesterol; of 1.3% (RS) and 2.6% (HR) for systolic blood pressure; of 0.5% (RS) and 0.9% (HR) for body weight; and 8.8% (RS) and 15.2% (HR) for cigarette consumption. The net reduction of coronary risk estimated by the multiple logistic equation was 12% in RS and 17% in HR. PMID:6844301

  4. Associations between bicycling and carotid arterial stiffness in adolescents: The European Youth Hearts Study.

    PubMed

    Ried-Larsen, M; Grøntved, A; Østergaard, L; Cooper, A R; Froberg, K; Andersen, L B; Møller, N C

    2015-10-01

    The aim of the study was to investigate the associations between bicycling and carotid arterial stiffness, independent of objectively measured moderate-and-vigorous physical activity. This cross-sectional study included 375 adolescents (age 15.7 ± 0.4 years) from the Danish site of the European Youth Heart Study. Total frequency of bicycle usage was assessed by self-report, and carotid arterial stiffness was assessed using B-mode ultrasound. After adjusting for pubertal status, body height, and objectively measured physical activity and other personal lifestyle and demographic factors, boys using their bicycle every day of the week displayed a higher carotid arterial compliance {standard beta 0.47 [95% confidence interval (CI) 0.07-0.87]} and distension [standard beta 0.38 (95% CI -0.04 to 0.81)]. Boys using their bicycle every day of the week furthermore displayed a lower Young's elastic modulus [standard beta -0.48 (95% CI -0.91 to -0.06)]. Similar trends were observed when investigating the association between commuter bicycling and carotid arterial stiffness. These associations were not observed in girls. Our observations suggest that increasing bicycling in adolescence may be beneficial to carotid arterial health among boys. PMID:25156494

  5. Heart failure overview

    MedlinePlus

    ... your heart contract at the same time. A defibrillator sends an electrical pulse to stop life-threatening ... heart rhythms. These people often receive an implanted defibrillator. When to Contact a Medical Professional Call your ...

  6. Cyanotic heart disease

    MedlinePlus

    ... or rhythms The treatment of choice for most congenital heart diseases is surgery to repair the defect . There are ... Some inherited factors may play a role in congenital heart disease. Many family members may be affected. If you ...

  7. Rationale and design of the carvedilol or metoprolol European trial in patients with chronic heart failure: COMET.

    PubMed

    Poole-Wilson, Philip A; Cleland, John G F; Di Lenarda, Andrea; Hanrath, Peter; Komajda, Michel; Metra, Marco; J Remme, Willem; Swedberg, Karl; Torp-Pedersen, Christian

    2002-06-01

    In large clinical trials both carvedilol and metoprolol have been shown to reduce mortality and morbidity in patients with chronic heart failure. Carvedilol is an adrenoceptor antagonist, which inhibits beta(1)-, beta(2)-, and alpha(1)-adrenergic receptors. Carvedilol has additional metabolic and antioxidant properties. Metoprolol is a selective antagonist of beta(1)-adrenergic receptors. The carvedilol or metoprolol European trial (COMET) is the first study to investigate whether beta-blocking agents with differing pharmacological profiles exert different effects on morbidity and mortality in patients with chronic heart failure. 3029 patients from 15 different European countries were enrolled into COMET and will be followed until 1020 fatal events have been observed, unless the data and safety monitoring committee (DSMC) recommends early termination. The target dose for carvedilol is 25 mg bid and for metoprolol tartrate 50 mg bid. This manuscript outlines the rationale, design and possible outcomes of COMET. PMID:12034158

  8. Clinical trials update from the European Society of Cardiology-Heart Failure meeting 2015: AUGMENT-HF, TITRATION, STOP-HF, HARMONIZE, LION HEART, MOOD-HF, and renin-angiotensin inhibitors in patients with heart and renal failure.

    PubMed

    Pellicori, Pierpaolo; Clark, Andrew L

    2015-09-01

    This article provides an overview on the key trials relevant to the pathophysiology, prevention, and treatment of heart failure (HF) presented at the Heart Failure Association (HFA) of the European Society of Cardiology (ESC) annual meeting held in Seville, Spain in May 2015. Trials reported include AUGMENT-AF (myocardial injections of calcium-alginate hydrogel), a propensity score-matched study of renin-angiotensin system antagonists in patients with HF and severe renal dysfunction, HARMONIZE (sodium zirconium cyclosilicate used to bind potassium), TITRATION, comparing two regimes for introducing LCZ696, STOP-HF, a trial of intramyocardial stromal cell-derived factor-1, MOOD-HF (escitalopram for patients with heart failure and depression), and LION HEART, a trial of intermittent levosimendan therapy. Unpublished reports should be considered as preliminary, since analyses may change in the final publication. PMID:26289928

  9. [First in Russia experience of radiofrequency ablation with the help of robotic system of magnetic navigation on the occasion of heart rhythm disturbances].

    PubMed

    Ardashev, V N; Ardashev, A V; Zheliakov, E G; Shavarov, A A; Rybachenko, M S; Koshcheeva, L A

    2007-01-01

    We present first in Russia experience of interventional treatment of 15 patients (11 men, 4 women, mean age 34.2 +/- 13.9 years) in whom operations of endocardial electrophysiological study (endoEPS) and radiofrequency ablation (RFA) with the help of robotic system of magnetic navigation were carried out because of various disturbances of cardiac rhythm. WPW syndrome and atrioventricular reciprocal tachycardia were verified in 8 patients (in 2 women), ventricular disturbances of rhythm -- in 4 (2 women), atrioventricular nodal reciprocal tachycardia in 3. RFA was effective in all cases what was confirmed in the course of control protocol of endoEPS. Complications related to the conduction of the procedure were not noted. Average duration of the operation was 82 +/- 32 min, mean duration of RF application -- 3.2 +/- 1.1 min. Average duration of fluoroscopic exposure of a patient and physician was 22 +/- 4 min and 3 +/- 1 min, respectively. In 1 patient with WPW syndrome recurrence of anterograde conduction along right anterior-septal accessory atrioventricular pathway (AAP) emerged on the second day after operation. Repeat session with the use of manual technique of irrigation RFA lead to persistent elimination of conduction along AAP. In other cases no recurrences of cardiac rhythm disturbances were observed during 10.2 +/- 1.2 months of follow up in the absence of antiarrhythmic maintenance therapy. The use of robotic system of magnetic navigation for mapping and RFA is highly effective and safe method of treatment of patients with various disorders of cardiac rhythm allowing to lessen significantly radiation burden on the operating physician. PMID:18260929

  10. Metabolic circadian rhythms in embryonic turtles.

    PubMed

    Loudon, Fiona Kay; Spencer, Ricky-John; Strassmeyer, Alana; Harland, Karen

    2013-07-01

    Oviparous species are model organisms for investigating embryonic development of endogenous physiological circadian rhythms without the influence of maternal biorhythms. Recent studies have demonstrated that heart rates and metabolic rates of embryonic turtles are not constant or always maximal and can be altered in response to the presence of embryos at a more advanced stage of development within the nest. A first step in understanding the physiological mechanisms underpinning these responses in embryonic ectothermic organisms is to develop metabolic profiles (e.g., heart rate) at different temperatures throughout incubation. Heart beat and rhythmic patterns or changes in development may represent important signals or cues within a nest and may be vital to coordinate synchronous hatching well in advance of the final stages of incubation. We developed baseline embryonic heart-rate profiles of embryos of the short-necked Murray River turtle (Emydura macquarii) to determine the stage of embryogenesis that metabolic circadian rhythms become established, if at all. Eggs were incubated at constant temperatures (26°C and 30°C) and heart rates were monitored at 6-h intervals over 24 h every 7-11 days until hatching. Circadian heart rate rhythms were detected at the mid-gestation period and were maintained until hatching. Heart rates throughout the day varied by up to 20% over 24 h and were not related to time of day. This study demonstrated that endogenous metabolic circadian rhythms in developing embryos in turtle eggs establish earlier in embryogenesis than those documented in other vertebrate taxa during embryogenesis. Early establishment of circadian rhythms in heart rates may be critical for communication among embryos and synchrony in hatching and emergence from the nest. PMID:23652198

  11. Adherence of heart failure patients to exercise: barriers and possible solutions: a position statement of the Study Group on Exercise Training in Heart Failure of the Heart Failure Association of the European Society of Cardiology.

    PubMed

    Conraads, Viviane M; Deaton, Christi; Piotrowicz, Ewa; Santaularia, Nuria; Tierney, Stephanie; Piepoli, Massimo F; Pieske, Burkert; Schmid, Jean-Paul; Dickstein, Kenneth; Ponikowski, Piotr P; Jaarsma, Tiny

    2012-05-01

    The practical management of heart failure remains a challenge. Not only are heart failure patients expected to adhere to a complicated pharmacological regimen, they are also asked to follow salt and fluid restriction, and to cope with various procedures and devices. Furthermore, physical training, whose benefits have been demonstrated, is highly recommended by the recent guidelines issued by the European Society of Cardiology, but it is still severely underutilized in this particular patient population. This position paper addresses the problem of non-adherence, currently recognized as a main obstacle to a wide implementation of physical training. Since the management of chronic heart failure and, even more, of training programmes is a multidisciplinary effort, the current manuscript intends to reach cardiologists, nurses, physiotherapists, as well as psychologists working in the field. PMID:22499542

  12. Who Needs Heart Surgery?

    MedlinePlus

    ... disease (CHD) Fix heart valves that don't work well Control abnormal heart rhythms Place medical devices Replace a damaged heart with a healthy one If other treatments—such as lifestyle changes, medicines, and medical ... surgeon will work with you to decide whether you need heart ...

  13. Flight Modes in Migrating European Bee-Eaters: Heart Rate May Indicate Low Metabolic Rate during Soaring and Gliding

    PubMed Central

    Sapir, Nir; Wikelski, Martin; McCue, Marshall D.; Pinshow, Berry; Nathan, Ran

    2010-01-01

    Background Many avian species soar and glide over land. Evidence from large birds (mb>0.9 kg) suggests that soaring-gliding is considerably cheaper in terms of energy than flapping flight, and costs about two to three times the basal metabolic rate (BMR). Yet, soaring-gliding is considered unfavorable for small birds because migration speed in small birds during soaring-gliding is believed to be lower than that of flapping flight. Nevertheless, several small bird species routinely soar and glide. Methodology/Principal Findings To estimate the energetic cost of soaring-gliding flight in small birds, we measured heart beat frequencies of free-ranging migrating European bee-eaters (Merops apiaster, mb∼55 g) using radio telemetry, and established the relationship between heart beat frequency and metabolic rate (by indirect calorimetry) in the laboratory. Heart beat frequency during sustained soaring-gliding was 2.2 to 2.5 times lower than during flapping flight, but similar to, and not significantly different from, that measured in resting birds. We estimated that soaring-gliding metabolic rate of European bee-eaters is about twice their basal metabolic rate (BMR), which is similar to the value estimated in the black-browed albatross Thalassarche (previously Diomedea) melanophrys, mb∼4 kg). We found that soaring-gliding migration speed is not significantly different from flapping migration speed. Conclusions/Significance We found no evidence that soaring-gliding speed is slower than flapping flight in bee-eaters, contradicting earlier estimates that implied a migration speed penalty for using soaring-gliding rather than flapping flight. Moreover, we suggest that small birds soar and glide during migration, breeding, dispersal, and other stages in their annual cycle because it may entail a low energy cost of transport. We propose that the energy cost of soaring-gliding may be proportional to BMR regardless of bird size, as theoretically deduced by earlier studies

  14. [Medicinal rhythm control in atrial fibrillation].

    PubMed

    Nowak, Bernd; Fürnkranz, Alexander

    2014-03-01

    Medicinal antiarrhythmic therapy is either used in the acute setting to convert atrial fibrillation to sinus rhythm or as chronic medication to preserve sinus rhythm if a rhythm control strategy is followed. The choice of the antiarrhythmic agent is based on the presence or absence of structural heart disease. In addition, oral anticoagulation should be established according to current guidelines. In the acute setting the armamentarium comprises flecainide, propafenone, vernakalant and amiodarone. Usually, combination therapy with an atrioventricular (AV) node slowing drug (a beta blocker or verapamil) is used. For chronic rhythm control a class IC drug, such as sotalol, dronedarone and amiodarone is given depending on the comorbidities. In the absence of structural heart disease, rare episodes of paroxysmal atrial fibrillation can be treated by a pill-in-the-pocket strategy, i.e. self-administered pharmacological cardioversion with flecainide or propafenone. Despite recent advances in catheter ablation of atrial fibrillation, medical rhythm control continues to play an important role due to its ubiquitous availability and relatively easy use. The risk for proarrhythmia has to be evaluated in all patients. PMID:24549989

  15. Activity in the ferret: oestradiol effects and circadian rhythms

    NASA Technical Reports Server (NTRS)

    Stockman, E. R.; Albers, H. E.; Baum, M. J.; Wurtman, R. J. (Principal Investigator)

    1985-01-01

    The present study was conducted to determine whether oestradiol increases activity in the European ferret (Mustela furo), whether this effect is sexually dimorphic, and whether a 24-h rhythm is present in the ferret's daily activity. The activity of male and female adult, postpubertally gonadectomized ferrets was monitored while they were maintained singly on a 13:11 light-dark cycle, before and after implantation with oestradiol-17 beta. Gonadectomized male and female ferrets exhibited equal levels of activity, and neither sex exhibited a significant change in activity following oestradiol implantation. None of the ferrets exhibited a strong circadian rhythm, although weak 24-h rhythms and shorter harmonic rhythms were present. Golden hamsters (Mesocricetus auratus), monitored in an identical manner, exhibited strong circadian rhythms. It was concluded that oestradiol administration may not cause an increase in activity in the ferret, and that this species lacks a strong circadian activity rhythm.

  16. Circadian rhythm asynchrony in man during hypokinesis.

    NASA Technical Reports Server (NTRS)

    Winget, C. M.; Vernikos-Danellis, J.; Cronin, S. E.; Leach, C. S.; Rambaut, P. C.; Mack, P. B.

    1972-01-01

    Posture and exercise were investigated as synchronizers of certain physiologic rhythms in eight healthy male subjects in a defined environment. Four subjects exercised during bed rest. Body temperature (BT), heart rate, plasma thyroid hormone, and plasma steroid data were obtained from the subjects for a 6-day ambulatory equilibration period before bed rest, 56 days of bed rest, and a 10-day recovery period after bed rest. The results indicate that the mechanism regulating the circadian rhythmicity of the cardiovascular system is rigorously controlled and independent of the endocrine system, while the BT rhythm is more closely aligned to the endocrine system.

  17. [Rhythms, depressions and light].

    PubMed

    Johnsson, Anders; Moan, Johan

    2006-04-01

    Many aspects of life in plants, animals and humans are controlled by light. Endogenous, so-called circadian rhythms in the body deviate from the exact 24-hour day and have typically a period of around 25.5 hours in man. Normally these rhythms adapt to the external 24-hour day-and night changes but under constant conditions the rhythms can free run. Many studies show how important the interplay between light and the circadian rhythms are for man as well as for other organisms. The control of these rhythms by light is mediated via the retina and the melatonin system in man. The adaptation of the rhythms is very important in shift work, in rapid jet lag travels over time zones, etc. Organisms often use the circadian rhythm to determine the length of day and of night, a feature that has given rise to the term biological clocks. A biological clock provides possibilities to determine the proper time for physiological processes to start in plants and animals (flowering, hibernation etc). The importance of light and circadian rhythms for seasonal affective disorders and manic-depressive disorders is also discussed. For several organisms one has now been able to specify genes that determine the period of the clocks. The rhythmic physiologic processes, the light reactions and the general importance of light for rhythms and for man are now studied at the molecular level. PMID:16619063

  18. Occupational class and ischemic heart disease mortality in the United States and 11 European countries.

    PubMed Central

    Kunst, A E; Groenhof, F; Andersen, O; Borgan, J K; Costa, G; Desplanques, G; Filakti, H; Giraldes, M do R; Faggiano, F; Harding, S; Junker, C; Martikainen, P; Minder, C; Nolan, B; Pagnanelli, F; Regidor, E; Vågerö, D; Valkonen, T; Mackenbach, J P

    1999-01-01

    OBJECTIVES: Twelve countries were compared with respect to occupational class differences in ischemic heart disease mortality in order to identify factors that are associated with smaller or larger mortality differences. METHODS: Data on mortality by occupational class among men aged 30 to 64 years were obtained from national longitudinal or cross-sectional studies for the 1980s. A common occupational class scheme was applied to most countries. Potential effects of the main data problems were evaluated quantitatively. RESULTS: A north-south contrast existed within Europe. In England and Wales, Ireland, and Nordic countries, manual classes had higher mortality rates than nonmanual classes. In France, Switzerland, and Mediterranean countries, manual classes had mortality rates as low as, or lower than, those among nonmanual classes. Compared with Northern Europe, mortality differences in the United States were smaller (among men aged 30-44 years) or about as large (among men aged 45-64 years). CONCLUSIONS: The results underline the highly variable nature of socioeconomic inequalities in ischemic heart disease mortality. These inequalities appear to be highly sensitive to social gradients in behavioral risk factors. These risk factor gradients are determined by cultural as well as socioeconomic developments. PMID:9987464

  19. Understanding calendar rhythm.

    PubMed

    Reyes, D P

    1983-01-01

    Rhythm has been among the family planning methods endorsed since the start of the National Population Program in the Philippines, but it has not been given as much emphasis as the other methods such as oral contraception (OC), the IUD, and sterilization. For several years, no systematic effort was made to promote the effective use of rhythm. The 1978 Community Outreach Survey (COS) tried to determine the extent to which contraceptive methods were being used in the Outreach Project areas. The project covered 2,000 barangay service points (BSPs) with 1.76 million married couples of reproductive age (MCRA), representing 32% of the estimated total MCRA in the Philippines. The COS findings revealed that, of the total sexually active married women aged 15-49, 48% were using contraceptive methods. Of these, only 11.4% were using modern methods, 20% were using other program methods (rhythm, condom, and combination of rhythm and condom); and 16.7% were using nonprogram methods (withdrawal, abstinence, and others). When used in combination with other methods, rhythm had a monthly continuation rate of 96%; when used alone, 94%. The COS data showed that the rhythm method is practiced by a large number of Filipino couples. With the renewed interest in rhythm, it became imperative for the program to help rhythm acceptors use the method more effectively and thus reduce user failure. There continues to be need for data on the "product image" of rhythm. These include the emotions that come into play in the acceptance or rejection of rhythm, the perceived side effects as well as advantages of the method, the ways women communicate their "safe" and "unsafe" days to their husbands, the manner in which couples prevent sexual contact during "unsafe" days, and the attitude of couples toward abstinence. Among important study findings were the following: couples choose rhythm because it does not disturb the sexual act, has no side effects, and poses no religious objections; 1 of the

  20. The Study of Biobehavioral Rhythms in a Psychology Laboratory Course.

    ERIC Educational Resources Information Center

    Rowland, David L.; Wesselhoft, Theresa

    1998-01-01

    Reports on a laboratory experiment where students measured their heart rate, blood pressure, mood, alertness, and cognitive performance. Measures showed significant circadian heart rhythm variations. They were strongly correlated and peaked at different times. Discusses the implications of this and students' reactions to the experiment. (MJP)

  1. Echocardiography for cardiac resynchronization therapy: recommendations for performance and reporting--a report from the American Society of Echocardiography Dyssynchrony Writing Group endorsed by the Heart Rhythm Society.

    PubMed

    Gorcsan, John; Abraham, Theodore; Agler, Deborah A; Bax, Jeroen J; Derumeaux, Genevieve; Grimm, Richard A; Martin, Randy; Steinberg, Jonathan S; Sutton, Martin St John; Yu, Cheuk-Man

    2008-03-01

    Echocardiography plays an evolving and important role in the care of heart failure patients treated with biventricular pacing, or cardiac resynchronization therapy (CRT). Numerous recent published reports have utilized echocardiographic techniques to potentially aide in patient selection for CRT prior to implantation and to optimized device settings afterwards. However, no ideal approach has yet been found. This consensus report evaluates the contemporary applications of echocardiography for CRT including relative strengths and technical limitations of several techniques and proposes guidelines regarding current and possible future clinical applications. Principal methods advised to qualify abnormalities in regional ventricular activation, known as dyssynchrony, include longitudinal velocities by color-coded tissue Doppler and the difference in left ventricular to right ventricular ejection using routine pulsed Doppler, or interventricular mechanical delay. Supplemental measures of radial dynamics which may be of additive value include septal-to-posterior wall delay using M-mode in patients with non-ischemic disease with technically high quality data, or using speckle tracking radial strain. A simplified post-CRT screening for atrioventricular optimization using Doppler mitral inflow velocities is also proposed. Since this is rapidly changing field with new information being added frequently, future modification and refinements in approach are anticipated to continue. PMID:18314047

  2. Circadian rhythms of visual accommodation responses and physiological correlations.

    NASA Technical Reports Server (NTRS)

    Murphy, M. R.; Randle, R. J.; Williams, B. A.

    1972-01-01

    Use of a recently developed servocontrolled infrared optometer to continuously record the state of monocular focus while subjects viewed a visual target for which the stimulus to focus was systematically varied. Calculated parameters form recorded data - e.g., speeds of accommodation to approaching and receding targets, magnitude of accommodation to step changes in target distance, and amplitude and phase lag of response to sinusoidally varying stimuli were submitted to periodicity analyses. Ear canal temperature (ECT) and heart rate (HR) rhythms were also recorded for physiological correlation with accommodation rhythms. HR demonstrated a 24-hr rhythm, but ECT data did not.

  3. Sleep and circadian rhythms

    NASA Technical Reports Server (NTRS)

    Monk, Timothy H.

    1991-01-01

    Three interacting processes are involved in the preservation of circadian rhythms: (1) endogenous rhythm generation mechanisms, (2) entrainment mechanisms to keep these rhythms 'on track', and (3) exogenous masking processes stemming from changes in environment and bahavior. These processes, particularly the latter two, can be dramatically affected in individuals of advanced age and in space travelers, with a consequent disruption in sleep and daytime functioning. This paper presents results of a phase-shift experiment investigating the age-related effects of the exogeneous component of circadian rhythms in various physiological and psychological functions by comparing these functions in middle aged and old subjects. Dramatic differences were found between the two age groups in measures of sleep, mood, activation, and performance efficiency.

  4. Race May Influence Risk for Irregular Heart Beat

    MedlinePlus

    ... nlm.nih.gov/medlineplus/news/fullstory_158687.html Race May Influence Risk for Irregular Heart Beat Whites ... between the heart rhythm disorder atrial fibrillation and race, a new study says. Whites with heart failure ...

  5. Clinical and genetic features of rhabdoid tumors of the heart registered with the European Rhabdoid Registry (EU-RHAB).

    PubMed

    Bartelheim, Kerstin; Sumerauer, David; Behrends, Uta; Kodetova, Daniela; Kucera, Filip; Leuschner, Ivo; Neumayer, Petra; Oyen, Florian; Rübe, Christian; Siebert, Reiner; Schneppenheim, Reinhard; Seeringer, Angela; Vasovcak, Peter; Frühwald, Michael C

    2014-09-01

    Rhabdoid tumors are rare but highly aggressive malignancies of infancy and early childhood with a generally unfavorable prognosis. Despite a wide variety of anatomic locations rhabdoid tumors share mutational inactivation of the SWI/SNF (SWItch/Sucrose NonFermentable) core component gene SMARCB1 (also known as INI1, hSNF5 or BAF47) in chromosome 22. As this inactivation usually results in loss of SMARCB1 expression, detectable by an antibody against the SMARCB1 protein, the accurate diagnosis of a rhabdoid tumor may be more distinctly and frequently made. Several reports on rhabdoid tumors presenting in various anatomic sites outside the kidneys and CNS are on record. We report two cases of rhabdoid tumors originating in the heart (cardiac tissue), which were entered into the European Rhabdoid Registry (EU-RHAB). The first case presented with intracardial and -cranial lesions as well as malignant ascites, while the second patient demonstrated an isolated cardiac tumor. This induced a different therapeutic approach and subsequently different clinical course (death 7 weeks after diagnosis in patient 1). Patient 2 presented with a bifocal intracardial tumor without metastases and remains in complete remission for 46 months since diagnosis following multimodal therapy. The second case demonstrates that even in a potentially futile clinical situation early and accurate diagnosis followed by prompt and intensive multimodal therapy may offer prolonged survival, potential cure and improved quality of life. PMID:24972932

  6. No Statins Before Heart Surgery, Study Suggests

    MedlinePlus

    ... harm, a new study suggests. In that setting, Crestor (rosuvastatin) did not prevent either the abnormal heart rhythm ... who were having elective heart surgery to take Crestor or a placebo before surgery. The researchers found ...

  7. The association between aerobic fitness and physical activity in children and adolescents: the European youth heart study.

    PubMed

    Kristensen, Peter Lund; Moeller, Niels Christian; Korsholm, Lars; Kolle, Elin; Wedderkopp, Niels; Froberg, Karsten; Andersen, Lars Bo

    2010-09-01

    The link between aerobic fitness and physical activity in children has been studied in a number of earlier studies and the results have generally shown weak to moderate correlations. This overall finding has been widely questioned partly because of the difficulty in obtaining valid estimates of physical activity. This study investigated the cross-sectional and longitudinal relationship between aerobic fitness and physical activity in a representative sample of 9 and 15-year-old children (n = 1260 cross-sectional, n = 153 longitudinal). The specific goal was to improve past studies using an objective method of activity assessment and taking into account a number of major sources of error. Data came from the Danish part of the European youth heart study, 1997-2003. The cross-sectional results generally showed a weak to moderate association between aerobic fitness and physical activity with standardized regression coefficients ranging from 0.14 to 0.33. The longitudinal results revealed a tendency towards an interaction effect of baseline physical activity on the relationship between changes in physical activity and aerobic fitness. Moderate to moderately strong regression effect sizes were observed in the lower quadrant of baseline physical activity compared to weak effect sizes in the remaining quadrants. In conclusion, the present study confirms earlier findings of a weak to moderate association between aerobic fitness and physical activity in total population of children. However, the study also indicates that inactive children can achieve notable increase in aerobic fitness by increasing their habitual physical activity level. A potential physiological explanation for these results is highlighted. PMID:20458593

  8. GENERAL: Stochastic Alternating Dynamics for Synchronous EAD-Like Beating Rhythms in Cultured Cardiac Myocytes

    NASA Astrophysics Data System (ADS)

    Zhang, Ning; Zhang, Hui-Min; Liu, Zhi-Qiang; Ding, Xue-Li; Yang, Ming-Hao; Gu, Hua-Guang; Ren, Wei

    2009-11-01

    Dissolved cardiac myocytes can couple together and generate synchronous beatings in culture. We observed a synchronized early after-depolarization(EAD)-like rhythm in cultured cardiac myocytes and reproduced the experimental observation in a network mathematical model whose dynamics are close to a Hopf bifurcation. The mechanism for this EAD-like rhythm is attributed to noised-induced stochastic alternatings between the focus and the limit cycle. These results provide novel understandings for pathological heart rhythms like the early immature beatings.

  9. Circadian rhythms in myocardial metabolism and contractile function; influence of workload and oleate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multiple extra-cardiac stimuli, such as workload and circulating nutrients (e.g., fatty acids), known to influence myocardial metabolism and contractile function exhibit marked circadian rhythms. The aim of the present study was to investigate whether the rat heart exhibits circadian rhythms in its ...

  10. [Atrial fibrillation-pharmacological therapy for rate and rhythm control].

    PubMed

    Müller-Burri, Stephan Andreas

    2014-02-01

    The therapeutic management of patients with atrial fibrillation is based on the three pillars (1) prevention of thromboembolism, (2) rate control, and (3) rhythm control. Patients with one or more risk factors should be treated with an oral anticoagulants in order to prevent stroke and to reduce mortality. The goals of rate control, prevention of heart failure and alleviation of atrial fibrillation related symptoms, normally can be achieved by pharmacological agents slowing the conduction in the AV node (e. g. β-blockers, calcium channel blockers, digoxin). For patients remaining symptomatic despite sufficient rate control adding a rhythm control strategy may be considered. The currently available antiarrhythmic drugs (e. g. flecainide, propafenone, sotalol, dronedarone, amiodarone) are characterized by a rather low efficacy in maintaining sinus rhythm and various possibly life threatening side effects. Therefore, invasive therapies as catheter ablation are frequently needed to achieve rhythm control in symptomatic patients with atrial fibrillation. PMID:24463376

  11. Measuring Child Rhythm

    ERIC Educational Resources Information Center

    Payne, Elinor; Post, Brechtje; Astruc, Lluisa; Prieto, Pilar; Vanrell, Maria del Mar

    2012-01-01

    Interval-based rhythm metrics were applied to the speech of English, Catalan and Spanish 2, 4 and 6 year-olds, and compared with the (adult-directed) speech of their mothers. Results reveal that child speech does not fall into a well-defined rhythmic class: for all three languages, it is more "vocalic" (higher %V) than adult speech and has a…

  12. Biological Clocks & Circadian Rhythms

    ERIC Educational Resources Information Center

    Robertson, Laura; Jones, M. Gail

    2009-01-01

    The study of biological clocks and circadian rhythms is an excellent way to address the inquiry strand in the National Science Education Standards (NSES) (NRC 1996). Students can study these everyday phenomena by designing experiments, gathering and analyzing data, and generating new experiments. As students explore biological clocks and circadian…

  13. Speech rhythm: a metaphor?

    PubMed Central

    Nolan, Francis; Jeon, Hae-Sung

    2014-01-01

    Is speech rhythmic? In the absence of evidence for a traditional view that languages strive to coordinate either syllables or stress-feet with regular time intervals, we consider the alternative that languages exhibit contrastive rhythm subsisting merely in the alternation of stronger and weaker elements. This is initially plausible, particularly for languages with a steep ‘prominence gradient’, i.e. a large disparity between stronger and weaker elements; but we point out that alternation is poorly achieved even by a ‘stress-timed’ language such as English, and, historically, languages have conspicuously failed to adopt simple phonological remedies that would ensure alternation. Languages seem more concerned to allow ‘syntagmatic contrast’ between successive units and to use durational effects to support linguistic functions than to facilitate rhythm. Furthermore, some languages (e.g. Tamil, Korean) lack the lexical prominence which would most straightforwardly underpin prominence of alternation. We conclude that speech is not incontestibly rhythmic, and may even be antirhythmic. However, its linguistic structure and patterning allow the metaphorical extension of rhythm in varying degrees and in different ways depending on the language, and it is this analogical process which allows speech to be matched to external rhythms. PMID:25385774

  14. Rhythm Sticks without Music.

    ERIC Educational Resources Information Center

    Mackin, Rosemary

    2000-01-01

    Provides 11 specific rhythm stick activities for preschoolers and kindergartners to increase children's awareness of basic music theory. Lessons incorporated in these activities include tempo, dynamics, intensity, laterality, and directionality. Lessons also address children's awareness of personal space and improved listening skills. Instructions…

  15. Speech rhythm: a metaphor?

    PubMed

    Nolan, Francis; Jeon, Hae-Sung

    2014-12-19

    Is speech rhythmic? In the absence of evidence for a traditional view that languages strive to coordinate either syllables or stress-feet with regular time intervals, we consider the alternative that languages exhibit contrastive rhythm subsisting merely in the alternation of stronger and weaker elements. This is initially plausible, particularly for languages with a steep 'prominence gradient', i.e. a large disparity between stronger and weaker elements; but we point out that alternation is poorly achieved even by a 'stress-timed' language such as English, and, historically, languages have conspicuously failed to adopt simple phonological remedies that would ensure alternation. Languages seem more concerned to allow 'syntagmatic contrast' between successive units and to use durational effects to support linguistic functions than to facilitate rhythm. Furthermore, some languages (e.g. Tamil, Korean) lack the lexical prominence which would most straightforwardly underpin prominence of alternation. We conclude that speech is not incontestibly rhythmic, and may even be antirhythmic. However, its linguistic structure and patterning allow the metaphorical extension of rhythm in varying degrees and in different ways depending on the language, and it is this analogical process which allows speech to be matched to external rhythms. PMID:25385774

  16. [PREVALENCE OF ATRIAL RHYTHM DISTURBANCES IN CARDIAC PATIENTS WITH COMORBIDITIES].

    PubMed

    Velichko, V L; Naychuk, O V; Lagoda, D O; Amirova, G U

    2015-01-01

    Atrial arrhythmias are the most common among all cardiac arrhythmias. The prevalence of atrial arrhythmias is increasing worldwide and has an impact on health indicators such as the loss of ability to work and mortality and increases the overall cardiovascular risk and/or heart disease occurence. This study indicates a high prevalence of atrial arthythmias in patients with ischemic heart disease and requires more detailed study in order to develop methods of preventing the onset of cardiac rhythm disorders. PMID:26118041

  17. Current state of knowledge on Takotsubo syndrome: a Position Statement from the Taskforce on Takotsubo Syndrome of the Heart Failure Association of the European Society of Cardiology.

    PubMed

    Lyon, Alexander R; Bossone, Eduardo; Schneider, Birke; Sechtem, Udo; Citro, Rodolfo; Underwood, S Richard; Sheppard, Mary N; Figtree, Gemma A; Parodi, Guido; Akashi, Yoshihiro J; Ruschitzka, Frank; Filippatos, Gerasimos; Mebazaa, Alexandre; Omerovic, Elmir

    2016-01-01

    Takotsubo syndrome is an acute reversible heart failure syndrome that is increasingly recognized in modern cardiology practice. This Position Statement from the European Society of Cardiology Heart Failure Association provides a comprehensive review of the various clinical and pathophysiological facets of Takotsubo syndrome, including nomenclature, definition, and diagnosis, primary and secondary clinical subtypes, anatomical variants, triggers, epidemiology, pathophysiology, clinical presentation, complications, prognosis, clinical investigations, and treatment approaches. Novel structured approaches to diagnosis, risk stratification, and management are presented, with new algorithms to aid decision-making by practising clinicians. These also cover more complex areas (e.g. uncertain diagnosis and delayed presentation) and the management of complex cases with ongoing symptoms after recovery, recurrent episodes, or spontaneous presentation. The unmet needs and future directions for research in this syndrome are also discussed. PMID:26548803

  18. Circadian Rhythm Sleep Disorders

    PubMed Central

    Kim, Min Ju; Lee, Jung Hie; Duffy, Jeanne F.

    2014-01-01

    Objective To review circadian rhythm sleep disorders, including underlying causes, diagnostic considerations, and typical treatments. Methods Literature review and discussion of specific cases. Results Survey studies 1,2 suggest that up to 3% of the adult population suffers from a circadian rhythm sleep disorder (CRSD). However, these sleep disorders are often confused with insomnia, and an estimated 10% of adult and 16% of adolescent sleep disorders patients may have a CRSD 3-6. While some CRSD (such as jet lag) can be self-limiting, others when untreated can lead to adverse medical, psychological, and social consequences. The International Classification of Sleep Disorders classifies CRSD as dyssomnias, with six subtypes: Advanced Sleep Phase Type, Delayed Sleep Phase Type, Irregular Sleep Wake Type, Free Running Type, Jet Lag Type, and Shift Work Type. The primary clinical characteristic of all CRSD is an inability to fall asleep and wake at the desired time. It is believed that CRSD arise from a problem with the internal biological clock (circadian timing system) and/or misalignment between the circadian timing system and the external 24-hour environment. This misalignment can be the result of biological and/or behavioral factors. CRSD can be confused with other sleep or medical disorders. Conclusions Circadian rhythm sleep disorders are a distinct class of sleep disorders characterized by a mismatch between the desired timing of sleep and the ability to fall asleep and remain asleep. If untreated, CRSD can lead to insomnia and excessive daytime sleepiness, with negative medical, psychological, and social consequences. It is important for physicians to recognize potential circadian rhythm sleep disorders so that appropriate diagnosis, treatment, and referral can be made. PMID:25368503

  19. The primate seahorse rhythm.

    PubMed

    Campos, L M G; Cruz-Rizzolo, Roelf J; Pinato, L

    2015-07-10

    The main Zeitgeber, the day-night cycle, synchronizes the central oscillator which determines behaviors rhythms as sleep-wake behavior, body temperature, the regulation of hormone secretion, and the acquisition and processing of memory. Thus, actions such as acquisition, consolidation, and retrieval performed in the hippocampus are modulated by the circadian system and show a varied dependence on light and dark. To investigate changes in the hippocampus' cellular mechanism invoked by the day and night in a diurnal primate, this study analyzed the expression of PER2 and the calcium binding proteins (CaBPs) calbindin, calretinin and parvalbumin in the hippocampus of Sapajus apella, a diurnal primate, at two different time points, one during the day and one during the dark phase. The PER2 protein expression peaked at night in the antiphase described for the suprachiasmatic nucleus (SCN) of the same primate, indicating that hippocampal cells can present independent rhythmicity. This hippocampal rhythm was similar to that presented by diurnal but not nocturnal rodents. The CaBPs immunoreactivity also showed day/night variations in the cell number and in the cell morphology. Our findings provide evidence for the claim that the circadian regulation in the hippocampus may involve rhythms of PER2 and CaBPs expression that may contribute to the adaptation of this species in events and activities relevant to the respective periods. PMID:25862571

  20. Circadian Rhythms in Cyanobacteria.

    PubMed

    Cohen, Susan E; Golden, Susan S

    2015-12-01

    Life on earth is subject to daily and predictable fluctuations in light intensity, temperature, and humidity created by rotation of the earth. Circadian rhythms, generated by a circadian clock, control temporal programs of cellular physiology to facilitate adaptation to daily environmental changes. Circadian rhythms are nearly ubiquitous and are found in both prokaryotic and eukaryotic organisms. Here we introduce the molecular mechanism of the circadian clock in the model cyanobacterium Synechococcus elongatus PCC 7942. We review the current understanding of the cyanobacterial clock, emphasizing recent work that has generated a more comprehensive understanding of how the circadian oscillator becomes synchronized with the external environment and how information from the oscillator is transmitted to generate rhythms of biological activity. These results have changed how we think about the clock, shifting away from a linear model to one in which the clock is viewed as an interactive network of multifunctional components that are integrated into the context of the cell in order to pace and reset the oscillator. We conclude with a discussion of how this basic timekeeping mechanism differs in other cyanobacterial species and how information gleaned from work in cyanobacteria can be translated to understanding rhythmic phenomena in other prokaryotic systems. PMID:26335718

  1. Race May Influence Risk for Irregular Heart Beat

    MedlinePlus

    ... Whites with heart failure more likely to develop atrial fibrillation, research finds To use the sharing features on ... a strong link between the heart rhythm disorder atrial fibrillation and race, a new study says. Whites with ...

  2. Ordinal pattern statistics for the assessment of heart rate variability

    NASA Astrophysics Data System (ADS)

    Graff, G.; Graff, B.; Kaczkowska, A.; Makowiec, D.; Amigó, J. M.; Piskorski, J.; Narkiewicz, K.; Guzik, P.

    2013-06-01

    The recognition of all main features of a healthy heart rhythm (the so-called sinus rhythm) is still one of the biggest challenges in contemporary cardiology. Recently the interesting physiological phenomenon of heart rate asymmetry has been observed. This phenomenon is related to unbalanced contributions of heart rate decelerations and accelerations to heart rate variability. In this paper we apply methods based on the concept of ordinal pattern to the analysis of electrocardiograms (inter-peak intervals) of healthy subjects in the supine position. This way we observe new regularities of the heart rhythm related to the distribution of ordinal patterns of lengths 3 and 4.

  3. Nonlinear properties of cardiac rhythm abnormalities

    NASA Astrophysics Data System (ADS)

    Liebovitch, Larry S.; Todorov, Angelo T.; Zochowski, Michal; Scheurle, Daniela; Colgin, Laura; Wood, Mark A.; Ellenbogen, Kenneth A.; Herre, John M.; Bernstein, Robert C.

    1999-03-01

    Many physical processes have distributions of times between events that have non-normalizable, power law probability density functions (PDF's). The moments of such distributions are not defined. We found that the PDF's of the times between events of ventricular tachyarrhythmia (rapid heart rate) and premature ventricular contractions have a power law form indicative of a non-normalizable distribution, and that the timing between these events cannot be meaningfully characterized by the mean frequency of such events. The Hurst analysis showed that there were self-similar correlations in the data. These results indicate that the physical processes that disrupt the normal rhythm of the heart produce a fractal pattern in the timing between these events. It also suggests that the mean and the variance of the frequency of these events may not be good measures to assess the status of patients with these arrhythmias and determine the effectiveness of therapeutic procedures.

  4. Bleeding risk assessment and management in atrial fibrillation patients: a position document from the European Heart Rhythm Association, endorsed by the European Society of Cardiology Working Group on Thrombosis.

    PubMed

    Lip, Gregory Y H; Andreotti, Felicita; Fauchier, Laurent; Huber, Kurt; Hylek, Elaine; Knight, Eve; Lane, Deirdre A; Levi, Marcel; Marin, Francisco; Palareti, Gualtiero; Kirchhof, Paulus; Collet, Jean-Philippe; Rubboli, Andrea; Poli, Daniela; Camm, John

    2011-05-01

    Despite the clear net clinical benefit of oral anticoagulation (OAC) in atrial fibrillation (AF) patients at risk for stroke, major bleeding events (especially intra-cranial bleeds) may be devastating events when they do occur. The decision for OAC is often based on a careful assessment of both stroke risk and bleeding risk, but clinical scores for bleeding risk estimation are much less well validated than stroke risk scales. Also, the estimation of bleeding risk is rendered difficult since many of the known factors that increase bleeding risk overlap with stroke risk factors. As well as this, many factors that increase bleeding risk are transient, such as variable international normalized ratio values, operations, vascular procedures, or drug-drug and food-drug interactions. In this Position Document, we comprehensively review the published evidence and propose a consensus on bleeding risk assessments in AF patients, with a view to summarizing 'best practice' when approaching antithrombotic therapy in AF patients. We address the epidemiology and size of the problem of bleeding risk in AF and review established bleeding risk factors. We also summarize definitions of bleeding in the published literature. Patient values and preferences balancing the risk of bleeding against thrombo-embolism is reviewed, and the prognostic implications of bleeding are discussed. We also review bleeding risk stratification and currently published bleeding risk schema. A brief discussion of special situations [e.g. peri-ablation, peri-devices (implantable cardioverter-defibrillator, pacemakers) and presentation with acute coronary syndromes and/or requiring percutaneous coronary interventions/stents and bridging therapy], as well as a discussion of prevention of bleeds and managing bleeding complications, is made. Finally, this document also puts forwards consensus statements that may help to define evidence gaps and assist in everyday clinical practice. Bleeding risk is almost inevitably lower than stroke risk in patients with atrial fibrillation. Nonetheless, identification of patients at high risk of bleeding and delineation of conditions and situations associated with bleeding risk can help to refine antithrombotic therapy to minimize bleeding risk. PMID:21515596

  5. Position Paper of the European Society of Cardiology Working Group Cellular Biology of the Heart: cell-based therapies for myocardial repair and regeneration in ischemic heart disease and heart failure.

    PubMed

    Madonna, Rosalinda; Van Laake, Linda W; Davidson, Sean M; Engel, Felix B; Hausenloy, Derek J; Lecour, Sandrine; Leor, Jonathan; Perrino, Cinzia; Schulz, Rainer; Ytrehus, Kirsti; Landmesser, Ulf; Mummery, Christine L; Janssens, Stefan; Willerson, James; Eschenhagen, Thomas; Ferdinandy, Péter; Sluijter, Joost P G

    2016-06-14

    Despite improvements in modern cardiovascular therapy, the morbidity and mortality of ischaemic heart disease (IHD) and heart failure (HF) remain significant in Europe and worldwide. Patients with IHD may benefit from therapies that would accelerate natural processes of postnatal collateral vessel formation and/or muscle regeneration. Here, we discuss the use of cells in the context of heart repair, and the most relevant results and current limitations from clinical trials using cell-based therapies to treat IHD and HF. We identify and discuss promising potential new therapeutic strategies that include ex vivo cell-mediated gene therapy, the use of biomaterials and cell-free therapies aimed at increasing the success rates of therapy for IHD and HF. The overall aim of this Position Paper of the ESC Working Group Cellular Biology of the Heart is to provide recommendations on how to improve the therapeutic application of cell-based therapies for cardiac regeneration and repair. PMID:27055812

  6. Strange musical rhythms.

    PubMed

    Valentinuzzi, Max E; Hortt, Federico

    2014-01-01

    Music, along with its attached rhythm, has been with man for centuries, developing and evolving along with him. Its influence on human behavior and mood can reach levels whose limits are still unknown, especially in everything related to perception, where the whole nervous system is involved. Thus, physiology and psychology become strongly connected areas, while technology, through, for example, the production of music by electronic means, appears as a new unexpected ingredient that traditional composers and musicians of older times could not imagine. Obviously, bioengineering and its multiple branches are not absent either [1]?[4]. The literature is enormous with several specialized journals. When one looks back in time at the evolution of this complex area, the appearance of some kind of sudden jump (as a step function), which took place within a relatively recent short interval, is evident: music is now much more than what it used to be, and rhythm has made a step forward as if resurrecting and renewing the ancient Indian or African drums. PMID:25437475

  7. Sleep, Memory & Brain Rhythms

    PubMed Central

    Watson, Brendon O.; Buzsáki, György

    2015-01-01

    Sleep occupies roughly one-third of our lives, yet the scientific community is still not entirely clear on its purpose or function. Existing data point most strongly to its role in memory and homeostasis: that sleep helps maintain basic brain functioning via a homeostatic mechanism that loosens connections between overworked synapses, and that sleep helps consolidate and re-form important memories. In this review, we will summarize these theories, but also focus on substantial new information regarding the relation of electrical brain rhythms to sleep. In particular, while REM sleep may contribute to the homeostatic weakening of overactive synapses, a prominent and transient oscillatory rhythm called “sharp-wave ripple” seems to allow for consolidation of behaviorally relevant memories across many structures of the brain. We propose that a theory of sleep involving the division of labor between two states of sleep–REM and non-REM, the latter of which has an abundance of ripple electrical activity–might allow for a fusion of the two main sleep theories. This theory then postulates that sleep performs a combination of consolidation and homeostasis that promotes optimal knowledge retention as well as optimal waking brain function. PMID:26097242

  8. Risk-benefit assessment of ivabradine in the treatment of chronic heart failure

    PubMed Central

    Urbanek, Irmina; Kaczmarek, Krzysztof; Cygankiewicz, Iwona; Ptaszynski, Pawel

    2014-01-01

    Heart rate is not only a major risk marker in heart failure but also a general risk marker. Within the last few years, it has been demonstrated that reduction of resting heart rate to <70 bpm is of significant benefit for patients with heart failure, especially those with impaired left ventricular systolic function. Ivabradine is the first innovative drug synthesized to reduce heart rate. It selectively and specifically inhibits the pacemaker If ionic current, which reduces cardiac pacemaker activity. Therefore, the main effect of ivabradine therapy is a substantial lowering of heart rate. Ivabradine does not influence intracardiac conduction, contractility, or ventricular repolarization. According to the European Society of Cardiology guidelines, ivabradine should be considered in symptomatic patients (New York Heart Association functional class II–IV) with sinus rhythm, left ventricular ejection fraction ≤35%, and heart rate ≥70 bpm despite optimal treatment with a beta-blocker, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, and a mineralocorticoid receptor antagonist. As shown in numerous clinical studies, ivabradine improves clinical outcomes and quality of life and reduces the risk of death from heart failure or cardiovascular causes. Treatment with ivabradine is very well tolerated and safe, even at maximal recommended doses. PMID:24855390

  9. Breathing rhythms and emotions.

    PubMed

    Homma, Ikuo; Masaoka, Yuri

    2008-09-01

    Respiration is primarily regulated for metabolic and homeostatic purposes in the brainstem. However, breathing can also change in response to changes in emotions, such as sadness, happiness, anxiety or fear. Final respiratory output is influenced by a complex interaction between the brainstem and higher centres, including the limbic system and cortical structures. Respiration is important in maintaining physiological homeostasis and co-exists with emotions. In this review, we focus on the relationship between respiration and emotions by discussing previous animal and human studies, including studies of olfactory function in relation to respiration and the piriform-amygdala in relation to respiration. In particular, we discuss oscillations of piriform-amygdala complex activity and respiratory rhythm. PMID:18487316

  10. Cross-cultural, age and gender validation of a computerised questionnaire measuring personal, social and environmental associations with children's physical activity: the European Youth Heart Study

    PubMed Central

    Ommundsen, Yngvar; Page, Angie; Ku, Po-Wen; Cooper, Ashley R

    2008-01-01

    Objective This study investigated the construct validity of a computerised self-assessment tool to measure psychological, social and environmental influences of young peoples' physical activity. First, analyses of the measure's factorial validity, invariance across, age, gender culture were conducted. Second, the ability of the derived subscales to discriminate between children representing different levels of self-reported and objectively measured physical activity behaviour was examined. Methods Participants were 1875 boys and 2078 girls (total = 3958) aged 9–10 years (n = 1955, mean age = 9.65 ± 0.42) and 15–16 years (n = 2003, mean age = 15.49 ± 0.50) from four European countries in Northern, Southern and Eastern Europe who took part in the European Youth Heart Study (EYHS). Children completed the computerised self-assessment tool with support from the researcher if requested. Self-reported exercise and an objective measure of physical activity (Actigraph model 7164) were used for additional construct validation purposes. Results Overall evidence of good fit indicating satisfactory factorial validity and cross-cultural, age and gender invariance for 3 of the 4 measurement models were obtained. The majority of measures were also significantly different for those with high versus low levels of physical activity. Conclusion Overall, the computerised questionnaire holds promise for use cross-culturally with male and female children and adolescents to measure perceived personal, social and environmental influences on physical activity. Further development of the measures pertaining to perceived environmental influences seems warranted. PMID:18489736

  11. Circadian Rhythms in Photosynthesis 1

    PubMed Central

    Hennessey, Timothy L.; Field, Christopher B.

    1991-01-01

    Net carbon assimilation and stomatal conductance to water vapor oscillated repeatedly in red kidney bean, Phaseolus vulgaris L., plants transferred from a natural photoperiod to constant light. In a gas exchange system with automatic regulation of selected environmental and physiological variables, assimilation and conductance oscillated with a free-running period of approximately 24.5 hours. The rhythms in carbon assimilation and stomatal conductance were closely coupled and persisted for more than a week under constant conditions. A rhythm in assimilation occurred when either ambient or intercellular CO2 partial pressure was held constant, demonstrating that the rhythm in assimilation was not entirely the result of stomatal effects on CO2 diffusion. Rhythms in assimilation and conductance were not expressed in plants grown under constant light at a constant temperature, demonstrating that the rhythms did not occur spontaneously but were induced by an external stimulus. In plants grown under constant light with a temperature cycle, a rhythm was entrained in stomatal conductance but not in carbon assimilation, indicating that the oscillators driving the rhythms differed in their sensitivity to environmental stimuli. PMID:16668261

  12. Rhythms of the hippocampal network.

    PubMed

    Colgin, Laura Lee

    2016-04-01

    The hippocampal local field potential (LFP) shows three major types of rhythms: theta, sharp wave-ripples and gamma. These rhythms are defined by their frequencies, they have behavioural correlates in several species including rats and humans, and they have been proposed to carry out distinct functions in hippocampal memory processing. However, recent findings have challenged traditional views on these behavioural functions. In this Review, I discuss our current understanding of the origins and the mnemonic functions of hippocampal theta, sharp wave-ripples and gamma rhythms on the basis of findings from rodent studies. In addition, I present an updated synthesis of their roles and interactions within the hippocampal network. PMID:26961163

  13. [Manifestations of polymorphism of β1-adrenoreceptors in patients with newly diagnosed cardiac rhythm disorders].

    PubMed

    Afanas'ev, S A; Rebrova, T Iu; Batalov, R E; Muslimova, É F; Borisova, E V; Popov, S V

    2013-01-01

    Individual peculiarities of the receptor apparatus of cardiomyocytes may determine pathological features of heart activity and susceptibility to pharmaceuticals. The possible role of beta-adrenoreceptor polymorphism in the development of cardiac rhythm disturbances is assessed by PCR. Special attention is given to A145G polymorphism of the ADRB1 gene in 127 patients with primary cardiac rhythm disorders. It was shown that AJ45G polymorphism (Ser49Gly) at DNA sites encoding for the amino acid sequence of beta-1 adrenoreceptors can influence the development of sex-specific cardiac rhythm disorders. PMID:24437165

  14. Biological rhythms and vector insects

    PubMed Central

    Marques, Mirian David

    2013-01-01

    The adjustment of all species, animals and plants, to the Earth’s cyclic environments is ensured by their temporal organisation. The relationships between parasites, vectors and hosts rely greatly upon the synchronisation of their biological rhythms, especially circadian rhythms. In this short note, parasitic infections by Protozoa and by microfilariae have been chosen as examples of the dependence of successful transmission mechanisms on temporal components. PMID:24473803

  15. Stroke Prevention in Atrial Fibrillation and Valvular Heart Disease.

    PubMed

    Ahmad, Saad; Wilt, Heath

    2016-01-01

    There is a clinically staggering burden of disease stemming from cerebrovascular events, of which a majority are ischemic in nature and many are precipitated by atrial fibrillation (AF). AF can occur in isolation or in association with myocardial or structural heart disease. In the latter case, and when considering health at an international level, congenital and acquired valve-related diseases are frequent contributors to the current pandemic of AF and its clinical impact. Guidelines crafted by the American Heart Association, American College of Cardiology, European Society of Cardiology and Heart Rhythm Society underscore the use of vitamin K antagonists (VKAs) among patients with valvular heart disease, particularly in the presence of concomitant AF, to reduce the risk of ischemic stroke of cardioembolic origin; however, the non-VKAs, also referred to as direct, target-specific or new oral anticoagulants (NOACs), have not been actively studied in this particular population. In fact, each of the new agents is approved in patients with AF not caused by a valve problem. The aim of our review is to carefully examine the available evidence from pivotal phase 3 clinical trials of NOACs and determine how they might perform in patients with AF and concomitant valvular heart disease. PMID:27347228

  16. Stroke Prevention in Atrial Fibrillation and Valvular Heart Disease

    PubMed Central

    Ahmad, Saad; Wilt, Heath

    2016-01-01

    There is a clinically staggering burden of disease stemming from cerebrovascular events, of which a majority are ischemic in nature and many are precipitated by atrial fibrillation (AF). AF can occur in isolation or in association with myocardial or structural heart disease. In the latter case, and when considering health at an international level, congenital and acquired valve-related diseases are frequent contributors to the current pandemic of AF and its clinical impact. Guidelines crafted by the American Heart Association, American College of Cardiology, European Society of Cardiology and Heart Rhythm Society underscore the use of vitamin K antagonists (VKAs) among patients with valvular heart disease, particularly in the presence of concomitant AF, to reduce the risk of ischemic stroke of cardioembolic origin; however, the non-VKAs, also referred to as direct, target-specific or new oral anticoagulants (NOACs), have not been actively studied in this particular population. In fact, each of the new agents is approved in patients with AF not caused by a valve problem. The aim of our review is to carefully examine the available evidence from pivotal phase 3 clinical trials of NOACs and determine how they might perform in patients with AF and concomitant valvular heart disease. PMID:27347228

  17. Cross-cultural adaptation and reliability testing of Polish adaptation of the European Heart Failure Self-care Behavior Scale (EHFScBS)

    PubMed Central

    Uchmanowicz, Izabella; Łoboz-Rudnicka, Maria; Jaarsma, Tiny; Łoboz-Grudzień, Krystyna

    2014-01-01

    Background Development of simple instruments for determination of self-care levels in heart failure (HF) patients is a subject of ongoing research. One such instrument, gaining growing popularity worldwide, is the European Heart Failure Self-care Behavior Scale (EHFScBS). The aim of this study was to adapt and to test reliability of the Polish version of EHFScBS. Method A standard guideline was used for translation and cultural adaptation of the English version of EHFScBS into Polish. The study included 100 Polish HF patients aged between 24 and 91 years, among them 67 men and 33 women. Cronbach’s alpha was used for analysis of the internal consistency of EHFScBS. Results Mean total self-care score in the study group was 34.2±8.1 points. Good or satisfactory level of self-care were documented in four out of 12 analyzed EHFScBS domains. Cronbach’s alpha for the entire questionnaire was 0.64. The value of Cronbach’s alpha after deletion of specific items ranged from 0.55 to 0.65. Conclusion Polish HF patients present significant deficits of self-care, which are to a large extent associated with inefficacy of the public health care system. Apart from cultural characteristics, the socioeconomic context of the target population should be considered during language adaptation of EHFScBS, as well as during interpretation of data obtained with this instrument. A number of self-care–related behaviors may be optimized as a result of appropriate educational activities, also those offered by nursing personnel. PMID:25382973

  18. Correlates of objectively assessed physical activity and sedentary time in children: a cross-sectional study (The European Youth Heart Study)

    PubMed Central

    2009-01-01

    Background Identifying leisure time activities performed before and after school that influence time in physical activity (PA) and/or time spent sedentary can provide useful information when designing interventions aimed to promote an active lifestyle in young people. The purpose of this study was to examine associations between mode of transportation to school, outdoor play after school, participation in exercise in clubs, and TV viewing with objectively assessed PA and sedentary behaviour in children. Methods A total of 1327 nine- and 15-year-old children from three European countries (Norway, Estonia, Portugal) participated as part of the European Youth Heart Study. PA was measured during two weekdays and two weekend days using the MTI accelerometer, and average percent of time in moderate-to-vigorous PA (MVPA) and time spent sedentary were derived. Potential correlates were assessed by self-report. Independent associations between self-reported correlates with percent time in MVPA and percent time sedentary were analysed by general linear models, adjusted by age, gender, country, measurement period, monitored days and parental socio-economic status. Results In 9-year-olds, playing outdoors after school was associated with higher percent time in MVPA (P < 0.01), while participation in sport clubs was associated with higher percent time in MVPA (P < 0.01) in 15-year-olds. No associations with percent time sedentary were observed in either age group. Conclusion Frequency of outdoor play after school is a significant correlate for daily time in MVPA in 9-year-olds, while this correlate is attenuated in favour of participation in sport and exercise in clubs in 15-year-olds. Targeting walking to school or reduced TV viewing time in order to increase time in daily MVPA in children is unlikely to be sufficient. Correlates related to time spent sedentary need further examination. PMID:19735565

  19. How does the brain create rhythms?

    PubMed

    Szirmai, Imre

    2010-01-30

    Connection was found between rhythmic cortical activity and motor control. The 10 Hz micro-rhythm and the 20-30 Hz bursts represent two functional states of the somatomotor system. A correspondence of the central micro-rhythm of the motor cortex and the physiological hand tremor (8-12 Hz) is presumed. The precise tuning of the motor system can be estimated by the frequency of repetitive finger movements. In complex tapping exercise, the index finger is the most skillful, the 3rd, 4th and 5th fingers keep rhythm with less precision. It was found that the organization of mirror movements depends on the cortical representation of fingers. Mirror finger movements are more regular if the subject begins the motor action with the 5th (small) finger. Concerning cortical regulation of finger movements, it was suggested that there are two time-keeping systems in the brain; one with a sensitivity above and another with a sensitivity below the critical frequency of 3 Hz. The preferred meter which helps to maintain synchronous finger movements is the cadence of 4/4 and 8/8. We observed that the unlearned inward-outward sequential finger movement was equally impaired in nonmusician controls and patients with Parkinson-disease. In movement disorders, the ability of movement and the "clock-mechanism" are equally involved. The polyrhythmic finger movement is not our inborn ability, it has to be learned. The "timer" function, which regulates the rhythmic movement, is presumably localised in the basal ganglia or in the cerebellum. The meter of the music is built on the reciprocal values of 2 raised to the second to fifth power (1/1(2), 1/2(2), 1/2(3), 1/2(4), 1/2(5)). The EEG frequencies that we consider important in the regulation of conscious motor actions are approximately in the same domain (4, 8, 16, 32, 64 Hz). During music performance, an important neural process is the coupling of distant brain areas. Concerning melody, the musical taste of Europeans is octave-based. Musical

  20. Endogenous rhythms influence interpersonal synchrony.

    PubMed

    Zamm, Anna; Wellman, Chelsea; Palmer, Caroline

    2016-05-01

    Interpersonal synchrony, the temporal coordination of actions between individuals, is fundamental to social behaviors from conversational speech to dance and music-making. Animal models indicate constraints on synchrony that arise from endogenous rhythms: Intrinsic periodic behaviors or processes that continue in the absence of change in external stimulus conditions. We report evidence for a direct causal link between endogenous rhythms and interpersonal synchrony in a music performance task, which places high demands on temporal coordination. We first establish that endogenous rhythms, measured by spontaneous rates of individual performance, are stable within individuals across stimulus materials, limb movements, and time points. We then test a causal link between endogenous rhythms and interpersonal synchrony by pairing each musician with a partner who is either matched or mismatched in spontaneous rate and by measuring their joint behavior up to 1 year later. Partners performed melodies together, using either the same or different hands. Partners who were matched for spontaneous rate showed greater interpersonal synchrony in joint performance than mismatched partners, regardless of hand used. Endogenous rhythms offer potential to predict optimal group membership in joint behaviors that require temporal coordination. (PsycINFO Database Record PMID:26820249

  1. Categorization of Fetal Heart Rate Decelerations in American and European Practice: Importance and Imperative of Avoiding Framing and Confirmation Biases.

    PubMed

    Sholapurkar, Shashikant L

    2015-09-01

    Interpretation of electronic fetal monitoring (EFM) remains controversial and unsatisfactory. Fetal heart rate (FHR) decelerations are the commonest aberrant feature on cardiotocographs and considered "center-stage" in the interpretation of EFM. A recent American study suggested that the lack of correlation of American three-tier system to neonatal acidemia may be due to the current peculiar nomenclature of FHR decelerations leading to loss of meaning. The pioneers like Hon and Caldeyro-Barcia classified decelerations based primarily on time relationship to contractions and not on etiology per se. This critical analysis debates pros and cons of significant anchoring/framing and confirmation biases in defining different types of decelerations based primarily on the shape (slope) or time of descent. It would be important to identify benign early decelerations correctly to avoid unnecessary intervention as well as to improve the positive predictive value of the other types of decelerations. Currently the vast majority of decelerations are classed as "variable". This review shows that the most common rapid decelerations during contractions with trough corresponding to peak of contraction cannot be explained by "cord-compression" hypothesis but by direct/pure (defined here as not mediated through baro-/chemoreceptors) or non-hypoxic vagal reflex. These decelerations are benign, most likely and mainly a result of head-compression and hence should be called "early" rather than "variable". Standardization is important but should be appropriate and withstand scientific scrutiny. Significant framing and confirmation biases are necessarily unscientific and the succeeding three-tier interpretation systems and structures embodying these biases would be dysfunctional and clinically unhelpful. Clinical/pathophysiological analysis and avoidance of flaws/biases suggest that a more physiological and scientific categorization of decelerations should be based on time relationship to

  2. Categorization of Fetal Heart Rate Decelerations in American and European Practice: Importance and Imperative of Avoiding Framing and Confirmation Biases

    PubMed Central

    Sholapurkar, Shashikant L.

    2015-01-01

    Interpretation of electronic fetal monitoring (EFM) remains controversial and unsatisfactory. Fetal heart rate (FHR) decelerations are the commonest aberrant feature on cardiotocographs and considered “center-stage” in the interpretation of EFM. A recent American study suggested that the lack of correlation of American three-tier system to neonatal acidemia may be due to the current peculiar nomenclature of FHR decelerations leading to loss of meaning. The pioneers like Hon and Caldeyro-Barcia classified decelerations based primarily on time relationship to contractions and not on etiology per se. This critical analysis debates pros and cons of significant anchoring/framing and confirmation biases in defining different types of decelerations based primarily on the shape (slope) or time of descent. It would be important to identify benign early decelerations correctly to avoid unnecessary intervention as well as to improve the positive predictive value of the other types of decelerations. Currently the vast majority of decelerations are classed as “variable”. This review shows that the most common rapid decelerations during contractions with trough corresponding to peak of contraction cannot be explained by “cord-compression” hypothesis but by direct/pure (defined here as not mediated through baro-/chemoreceptors) or non-hypoxic vagal reflex. These decelerations are benign, most likely and mainly a result of head-compression and hence should be called “early” rather than “variable”. Standardization is important but should be appropriate and withstand scientific scrutiny. Significant framing and confirmation biases are necessarily unscientific and the succeeding three-tier interpretation systems and structures embodying these biases would be dysfunctional and clinically unhelpful. Clinical/pathophysiological analysis and avoidance of flaws/biases suggest that a more physiological and scientific categorization of decelerations should be based on

  3. Biological rhythms and mood disorders

    PubMed Central

    Salvatore, Paola; Indic, Premananda; Murray, Greg; Baldessarini, Ross J.

    2012-01-01

    Integration of several approaches concerning time and temporality can enhance the pathophysiological study of major mood disorders of unknown etiology. We propose that these conditions might be interpreted as disturbances of temporal profile of biological rhythms, as well as alterations of time-consciousness. Useful approaches to study time and temporality include philological suggestions, phenomenological and psychopathological conceptualizatíons, clinical descriptions, and research on circadian and ultradían rhythms, as well as nonlinear dynamics approaches to their analysis. PMID:23393414

  4. Control mechanisms in physiological rhythms

    NASA Technical Reports Server (NTRS)

    Mizell, S.

    1973-01-01

    A search was made for the factors involved in regulating rhythmic body functions. The basic premise was that at a particular point in time, any cell can normally act in one of two ways. It can either be engaged in dividing or carrying out its particular function. Experimental results indicate rhythmic functions are controlled by a lighting regime and that an inverse correlation exists between rhythms of cell division and cell function. Data also show rhythms are a function of animal sex and environment.

  5. Heart Health

    MedlinePlus

    ... Connected Home » Heart Health Heath and Aging Heart Health Your Heart Changes to Your Heart With ... are both taking steps toward heart health. Your Heart Your heart is a strong muscle about the ...

  6. Circadian rhythms and the suprachiasmatic nucleus in perinatal development, aging and Alzheimer's disease.

    PubMed

    Mirmiran, M; Swaab, D F; Kok, J H; Hofman, M A; Witting, W; Van Gool, W A

    1992-01-01

    Circadian rhythms are already present in the fetus. At a certain stage of pre-natal hypothalamic development (around 30 weeks of gestation) the fetus becomes responsive to maternal circadian signals. Moreover, recent studies showed that the fetal biological clock is able to generate circadian rhythms, as exemplified by the rhythms of body temperature and heart rate of pre-term babies in the absence of maternal or environmental entrainment factors. Pre-term babies that are deprived of maternal entrainment and kept under constant environmental conditions (e.g., continuous light) in the neonatal intensive care unit run the risk of developing a biological clock dysfunctioning. However, the fact should be acknowledged that at least in mice the development of the circadian pacemaker (i.e., SCN) does not depend on environmental influences (Davis and Menaker, 1981), although other data suggest that severe disruption of the maternal circadian rhythm indeed abolishes the circadian rhythm of the fetal SCN (Shibata and Moore, 1988). During aging and in particular in AD circadian rhythms are disturbed. These disturbances include phase advance and reduced period and amplitude, as well as an increased intradaily variability and a decreased interdaily stability of the rhythm. Among the factors underlying these changes the loss of SCN neurons seems to play a central role. Other contributory factors may be reduced amount of light, degenerative changes in the visual system and the level of activity and decreased melatonin. PMID:1480747

  7. Chaos control applied to cardiac rhythms represented by ECG signals

    NASA Astrophysics Data System (ADS)

    Borem Ferreira, Bianca; Amorim Savi, Marcelo; Souza de Paula, Aline

    2014-10-01

    The control of irregular or chaotic heartbeats is a key issue in cardiology. In this regard, chaos control techniques represent a good alternative since they suggest treatments different from those traditionally used. This paper deals with the application of the extended time-delayed feedback control method to stabilize pathological chaotic heart rhythms. Electrocardiogram (ECG) signals are employed to represent the cardiovascular behavior. A mathematical model is employed to generate ECG signals using three modified Van der Pol oscillators connected with time delay couplings. This model provides results that qualitatively capture the general behavior of the heart. Controlled ECG signals show the ability of the strategy either to control or to suppress the chaotic heart dynamics generating less-critical behaviors.

  8. The International Sweethearts of Rhythm.

    ERIC Educational Resources Information Center

    Sher, Liz

    1987-01-01

    The International Sweethearts of Rhythm, a popular, long-lived, all-female jazz band of the 1940s, were the first racially integrated women's band in America. Their achievement has been largely neglected by music historians. A brief history of the band is presented, and their significance is discussed. (BJV)

  9. Biochemical Oscillations and Cellular Rhythms

    NASA Astrophysics Data System (ADS)

    Goldbeter, Albert; Berridge, Foreword by M. J.

    1997-04-01

    1. Introduction; Part I. Glycolytic Oscillations: 2. Oscillatory enzymes: simple periodic behaviour in an allosteric model for glycolytic oscillations; Part II. From Simple to Complex Oscillatory Behaviour; 3. Birhythmicity: coexistence between two stable rhythms; 4. From simple periodic behaviour to complex oscillations, including bursting and chaos; Part III. Oscillations Of Cyclic Amo In Dictyostelium Cells: 5. Models for the periodic synthesis and relay of camp signals in Dictyostelium discoideum amoebae; 6. Complex oscillations and chaos in the camp signalling system of Dictyostelium; 7. The onset of camp oscillations in Dictyostelium as a model for the ontogenesis of biological rhythms; Part IV. Pulsatile Signalling In Intercellular Communication: 8. Function of the rhythm of intercellular communication in Dictyostelium. Link with pulsatile hormone secretion; Part V. Calcium Oscillations: 9. Oscillations and waves of intracellular calcium; Part VI. The Mitotic Oscillator: 10. Modelling the mitotic oscillator driving the cell division cycle; Part VII. Circadian Rhythms: 11. Towards a model for circadian oscillations in the Drosophila period protein (PER); 12. Conclusions and perspectives; References.

  10. Rhythm Deficits in "Tone Deafness"

    ERIC Educational Resources Information Center

    Foxton, Jessica M.; Nandy, Rachel K.; Griffiths, Timothy D.

    2006-01-01

    It is commonly observed that "tone deaf" individuals are unable to hear the beat of a tune, yet deficits on simple timing tests have not been found. In this study, we investigated rhythm processing in nine individuals with congenital amusia ("tone deafness") and nine controls. Participants were presented with pairs of 5-note sequences, and were…

  11. Circadian rhythms, the molecular clock, and skeletal muscle.

    PubMed

    Harfmann, Brianna D; Schroder, Elizabeth A; Esser, Karyn A

    2015-04-01

    Circadian rhythms are the approximate 24-h biological cycles that function to prepare an organism for daily environmental changes. They are driven by the molecular clock, a transcriptional:translational feedback mechanism that in mammals involves the core clock genes Bmal1, Clock, Per1/2, and Cry1/2. The molecular clock is present in virtually all cells of an organism. The central clock in the suprachiasmatic nucleus (SCN) has been well studied, but the clocks in the peripheral tissues, such as heart and skeletal muscle, have just begun to be investigated. Skeletal muscle is one of the largest organs in the body, comprising approximately 45% of total body mass. More than 2300 genes in skeletal muscle are expressed in a circadian pattern, and these genes participate in a wide range of functions, including myogenesis, transcription, and metabolism. The circadian rhythms of skeletal muscle can be entrained both indirectly through light input to the SCN and directly through time of feeding and activity. It is critical for the skeletal muscle molecular clock not only to be entrained to the environment but also to be in synchrony with rhythms of other tissues. When circadian rhythms are disrupted, the observed effects on skeletal muscle include fiber-type shifts, altered sarcomeric structure, reduced mitochondrial respiration, and impaired muscle function. Furthermore, there are detrimental effects on metabolic health, including impaired glucose tolerance and insulin sensitivity, which skeletal muscle likely contributes to considering it is a key metabolic tissue. These data indicate a critical role for skeletal muscle circadian rhythms for both muscle and systems health. Future research is needed to determine the mechanisms of molecular clock function in skeletal muscle, identify the means by which skeletal muscle entrainment occurs, and provide a stringent comparison of circadian gene expression across the diverse tissue system of skeletal muscle. PMID:25512305

  12. Physiological basis for human autonomic rhythms

    NASA Technical Reports Server (NTRS)

    Eckberg, D. L.

    2000-01-01

    Oscillations of arterial pressures, heart periods, and muscle sympathetic nerve activity have been studied intensively in recent years to explore otherwise obscure human neurophysiological mechanisms. The best-studied rhythms are those occurring at breathing frequencies. Published evidence indicates that respiratory fluctuations of muscle sympathetic nerve activity and electrocardiographic R-R intervals result primarily from the action of a central 'gate' that opens during expiration and closes during inspiration. Parallel respiratory fluctuations of arterial pressures and R-R intervals are thought to be secondary to arterial baroreflex physiology: changes in systolic pressure provoke changes in the R-R interval. However, growing evidence suggests that these parallel oscillations result from the influence of respiration on sympathetic and vagal-cardiac motoneurones rather than from baroreflex physiology. There is a rapidly growing literature on the use of mathematical models of low- and high-frequency (respiratory) R-R interval fluctuations in characterizing instantaneous 'sympathovagal balance'. The case for this approach is based primarily on measurements made with patients in upright tilt. However, the strong linear relation between such measures as the ratio of low- to high-frequency R-R interval oscillations and the angle of the tilt reflects exclusively the reductions of the vagal (high-frequency) component. As the sympathetic component does not change in tilt, the low- to high-frequency R-R interval ratio provides no proof that sympathetic activity increases. Moreover, the validity of extrapolating from measurements performed during upright tilt to measurements during supine rest has not been established. Nonetheless, it is clear that measures of heart rate variability provide important prognostic information in patients with cardiovascular diseases. It is not known whether reduced heart rate variability is merely a marker for the severity of disease or a

  13. Physiological basis for human autonomic rhythms.

    PubMed

    Eckberg, D L

    2000-07-01

    Oscillations of arterial pressures, heart periods, and muscle sympathetic nerve activity have been studied intensively in recent years to explore otherwise obscure human neurophysiological mechanisms. The best-studied rhythms are those occurring at breathing frequencies. Published evidence indicates that respiratory fluctuations of muscle sympathetic nerve activity and electrocardiographic R-R intervals result primarily from the action of a central 'gate' that opens during expiration and closes during inspiration. Parallel respiratory fluctuations of arterial pressures and R-R intervals are thought to be secondary to arterial baroreflex physiology: changes in systolic pressure provoke changes in the R-R interval. However, growing evidence suggests that these parallel oscillations result from the influence of respiration on sympathetic and vagal-cardiac motoneurones rather than from baroreflex physiology. There is a rapidly growing literature on the use of mathematical models of low- and high-frequency (respiratory) R-R interval fluctuations in characterizing instantaneous 'sympathovagal balance'. The case for this approach is based primarily on measurements made with patients in upright tilt. However, the strong linear relation between such measures as the ratio of low- to high-frequency R-R interval oscillations and the angle of the tilt reflects exclusively the reductions of the vagal (high-frequency) component. As the sympathetic component does not change in tilt, the low- to high-frequency R-R interval ratio provides no proof that sympathetic activity increases. Moreover, the validity of extrapolating from measurements performed during upright tilt to measurements during supine rest has not been established. Nonetheless, it is clear that measures of heart rate variability provide important prognostic information in patients with cardiovascular diseases. It is not known whether reduced heart rate variability is merely a marker for the severity of disease or a

  14. Adherence to the European Society of Cardiology (ESC) guidelines for chronic heart failure - A national survey of the cardiologists in Pakistan

    PubMed Central

    2011-01-01

    Background The aims of this study were to evaluate the awareness of and attitudes towards the 2005 European Society of Cardiology (ESC) guidelines for Heart Failure (HF) of the cardiologists in Pakistan and assess barriers to adherence to guidelines. Methods A cross-sectional survey was conducted in person from March to July 2009 to all cardiologists practicing in 4 major cities in Pakistan (Karachi, Lahore, Quetta and Peshawar). A validated, semi-structured questionnaire assessing ESC 2005 Guidelines for HF was used to obtain information from cardiologists. It included questions about awareness and relevance of HF guidelines (See Additional File 1). Respondents' management choices were compared with those of an expert panel based on the guidelines for three fictitious patient cases. Cardiologists were also asked about major barriers to adherence to guidelines. Results A total of 372 cardiologists were approached; 305 consented to participate (overall response rate, 82.0%). The survey showed a very high awareness of CHF guidelines; 97.4% aware of any guideline. About 13.8% considered ESC guidelines as relevant or very relevant for guiding treatment decisions while 92.8% chose AHA guidelines in relevance. 87.2% of respondents perceived that they adhered to the HF guidelines. For the patient cases, the proportions of respondents who made recommendations that completely matched those of the guidelines were 7% (Scenario 1), 0% (Scenario 2) and 20% (Scenario 3). Respondents considered patient compliance (59%) and cost/health economics (50%) as major barriers to guideline implementation. Conclusion We found important self reported departures from recommended HF management guidelines among cardiologists of Pakistan. PMID:22093082

  15. Concepts in human biological rhythms

    PubMed Central

    Reinberg, Alain; Ashkenazi, Israel

    2003-01-01

    Biological rhythms and their temporal organization are adaptive phenomena to periodic changes in environmental factors linked to the earth's rotation on its axis and around the sun. Experimental data from the plant and animal kingdoms have led to many models and concepts related to biological clocks that help describe and understand the mechanisms of these changes. Many of the prevailing concepts apply to all organisms, but most of the experimental data are insufficient to explain the dynamics of human biological clocks. This review presents phenomena thai are mainly characteristic ofand unique to - human chronobiology, and which cannot be fully explained by concepts and models drawn from laboratory experiments. We deal with the functional advantages of the human temporal organization and the problem of desynchronization, with special reference to the period (τ) of the circadian rhythm and its interindividual and intraindividual variability. We describe the differences between right- and left-hand rhythms suggesting the existence of different biological clocks in the right and left cortices, Desynchronization of rhythms is rather frequent (one example is night shift workers). In some individuals, desynchronization causes no clinical symptoms and we propose the concept of “allochronism” to designate a variant of the human temporal organization with no pathological implications. We restrict the term “dyschronism” to changes or alterations in temporal organization associated with a set of symptoms similar to those observed in subjects intolerant to shift work, eg, persisting fatigue and mood and sleep alterations. Many diseases involve chronic deprivation of sleep at night and constitute conditions mimicking thai of night shift workers who are intolerant to desynchronization. We also present a genetic model (the dian-circadian model) to explain interindividual differences in the period of biological rhythms in certain conditions. PMID:22033796

  16. Adaptation of sleep and circadian rhythms to the Antarctic summer - A question of zeitgeber strength

    NASA Technical Reports Server (NTRS)

    Gander, Philippa H.; Macdonald, John A.; Montgomery, John C.; Paulin, Michael G.

    1991-01-01

    Adaptation of sleep and circadian rhythms was examined in three temperate zone dwellers arriving in Antarctica during summer. Rectal temperature, wrist activity, and heart rate were monitored continuously, sleep timing and quality noted on awakening, and mood and fatigue rated every 2 h while awake. Sleep was poorer in 2/3 subjects in Antarctica, where all subjects reported more difficulty rising. Sleep occurred at the same clock times in New Zealand and Antarctica, however, the rhythms of temperature, activity, and heart rate underwent a delay of about of 2 h. The subject with the most Antarctic experience had the least difficulty adapting to sleeping during constant daylight. The subject with the most delayed circadian rhythms had the most difficulty. The delay in the circadian system with respect to sleep and clock time is hypothesized to be due to differences in zeitgeber strength and/or zeitgeber exposure between Antarctica and New Zealand.

  17. Heart Health - Brave Heart

    MedlinePlus

    ... Bar Home Current Issue Past Issues Cover Story Heart Health Brave Heart Past Issues / Winter 2009 Table of Contents For ... you can have a good life after a heart attack." Lifestyle Changes Surviving—and thriving—after such ...

  18. Sleep Apnea May Raise Heart Risks in People with Pacemakers

    MedlinePlus

    ... risk for a dangerous heart rhythm disorder called atrial fibrillation, a new study suggests. With sleep apnea, breathing ... sleep disorder is a known risk factor for atrial fibrillation, but the risk for pacemaker patients with sleep ...

  19. Heart transplant

    MedlinePlus

    ... 10 years. Alternative Names Cardiac transplant; Transplant - heart; Transplantation - heart Images Heart, section through the middle Heart, ... 28. Bernstein D. Pediatric heart and heart-lung transplantation. In: Kliegman RM, Behrman RE, Jenson HB, Stanton ...

  20. Heart Failure

    MedlinePlus

    ... version of this page please turn Javascript on. Heart Failure What is Heart Failure? In heart failure, the heart cannot pump enough ... failure often experience tiredness and shortness of breath. Heart Failure is Serious Heart failure is a serious and ...

  1. Temporal Interactions between Cortical Rhythms

    PubMed Central

    Roopun, Anita K.; Kramer, Mark A.; Carracedo, Lucy M.; Kaiser, Marcus; Davies, Ceri H.; Traub, Roger D.; Kopell, Nancy J.; Whittington, Miles A.

    2008-01-01

    Multiple local neuronal circuits support different, discrete frequencies of network rhythm in neocortex. Relationships between different frequencies correspond to mechanisms designed to minimise interference, couple activity via stable phase interactions, and control the amplitude of one frequency relative to the phase of another. These mechanisms are proposed to form a framework for spectral information processing. Individual local circuits can also transform their frequency through changes in intrinsic neuronal properties and interactions with other oscillating microcircuits. Here we discuss a frequency transformation in which activity in two co-active local circuits may combine sequentially to generate a third frequency whose period is the concatenation sum of the original two. With such an interaction, the intrinsic periodicity in each component local circuit is preserved – alternate, single periods of each original rhythm form one period of a new frequency – suggesting a robust mechanism for combining information processed on multiple concurrent spatiotemporal scales. PMID:19225587

  2. Circadian Rhythm Control: Neurophysiological Investigations

    NASA Technical Reports Server (NTRS)

    Glotzbach, S. F.

    1985-01-01

    The suprachiasmatic nucleus (SCN) was implicated as a primary component in central nervous system mechanisms governing circadian rhythms. Disruption of the normal synchronization of temperature, activity, and other rhythms is detrimental to health. Sleep wake disorders, decreases in vigilance and performance, and certain affective disorders may result from or be exacerbated by such desynchronization. To study the basic neurophysiological mechanisms involved in entrainment of circadian systems by the environment, Parylene-coated, etched microwire electrode bundles were used to record extracellular action potentials from the small somata of the SCN and neighboring hypothalamic nuclei in unanesthetized, behaving animals. Male Wistar rats were anesthetized and chronically prepared with EEG ane EMG electrodes in addition to a moveable microdrive assembly. The majority of cells had firing rates 10 Hz and distinct populations of cells which had either the highest firing rate or lowest firing rate during sleep were seen.

  3. Diagnosis, Clinical Course, and 1-Year Outcome in Patients Hospitalized for Heart Failure With Preserved Ejection Fraction (from the Polish Cohort of the European Society of Cardiology Heart Failure Long-Term Registry).

    PubMed

    Kapłon-Cieślicka, Agnieszka; Tymińska, Agata; Peller, Michał; Balsam, Paweł; Ozierański, Krzysztof; Galas, Michalina; Marchel, Michał; Crespo-Leiro, Maria G; Maggioni, Aldo Pietro; Drożdż, Jarosław; Filipiak, Krzysztof J; Opolski, Grzegorz

    2016-08-15

    Compared with heart failure (HF) with reduced ejection fraction (HF-REF), the diagnosis of HF with preserved EF (HF-PEF) is more challenging. The aim of the study was to assess the prevalence of HF-PEF among patients hospitalized for HF, to evaluate the pertinence of HF-PEF diagnosis and to compare HF-PEF and HF-REF patients with respect to outcomes. The analysis included 661 Polish patients hospitalized for HF, selected from the European Society of Cardiology (ESC)-HF Long-Term Registry. Patients with an EF of ≥50% were included in the HF-PEF group and patients with an EF of <50% - in the HF-REF group. The primary end point was all-cause death at 1 year. The secondary end point was a composite of all-cause death and rehospitalization for HF at 1 year. HF-PEF was present in 187 patients (28%). Of those 187 patients, mitral inflow pattern was echocardiographically assessed in 116 patients (62%) and classified as restrictive/pseudonormal in 37 patients (20%). Compared with HF-REF subjects, patients with HF-PEF were older, more often female, and had a higher prevalence of hypertension, atrial fibrillation and sleep apnea. Despite lower B-type natriuretic peptide concentrations and lower prevalence of moderate-to-severe mitral regurgitation in patients with HF-PEF, congestive symptoms at admission were as severe as in patients with HF-REF. There were no significant differences in in-hospital mortality between the HF groups. One-year mortality was high in both groups (17% in HF-PEF vs 21% in HF-REF, p = 0.22). There was a trend toward a lower frequency of the secondary end point in the HF-PEF group (32% vs 40%, p = 0.07). In conclusion, in clinical practice, even easily obtainable echocardiographic indexes of diastolic dysfunction are relatively rarely acquired. One-year survival rate of patients with HF-PEF is not significantly better than that of patients with HF-REF. PMID:27374606

  4. Biological Rhythms in the Skin

    PubMed Central

    Matsui, Mary S.; Pelle, Edward; Dong, Kelly; Pernodet, Nadine

    2016-01-01

    Circadian rhythms, ≈24 h oscillations in behavior and physiology, are reflected in all cells of the body and function to optimize cellular functions and meet environmental challenges associated with the solar day. This multi-oscillatory network is entrained by the master pacemaker located in the suprachiasmatic nucleus (SCN) of the hypothalamus, which directs an organism’s rhythmic expression of physiological functions and behavior via a hierarchical system. This system has been highly conserved throughout evolution and uses transcriptional–translational autoregulatory loops. This master clock, following environmental cues, regulates an organism’s sleep pattern, body temperature, cardiac activity and blood pressure, hormone secretion, oxygen consumption and metabolic rate. Mammalian peripheral clocks and clock gene expression have recently been discovered and are present in all nucleated cells in our body. Like other essential organ of the body, the skin also has cycles that are informed by this master regulator. In addition, skin cells have peripheral clocks that can function autonomously. First described in 2000 for skin, this review summarizes some important aspects of a rapidly growing body of research in circadian and ultradian (an oscillation that repeats multiple times during a 24 h period) cutaneous rhythms, including clock mechanisms, functional manifestations, and stimuli that entrain or disrupt normal cycling. Some specific relationships between disrupted clock signaling and consequences to skin health are discussed in more depth in the other invited articles in this IJMS issue on Sleep, Circadian Rhythm and Skin. PMID:27231897

  5. Biological Rhythms in the Skin.

    PubMed

    Matsui, Mary S; Pelle, Edward; Dong, Kelly; Pernodet, Nadine

    2016-01-01

    Circadian rhythms, ≈24 h oscillations in behavior and physiology, are reflected in all cells of the body and function to optimize cellular functions and meet environmental challenges associated with the solar day. This multi-oscillatory network is entrained by the master pacemaker located in the suprachiasmatic nucleus (SCN) of the hypothalamus, which directs an organism's rhythmic expression of physiological functions and behavior via a hierarchical system. This system has been highly conserved throughout evolution and uses transcriptional-translational autoregulatory loops. This master clock, following environmental cues, regulates an organism's sleep pattern, body temperature, cardiac activity and blood pressure, hormone secretion, oxygen consumption and metabolic rate. Mammalian peripheral clocks and clock gene expression have recently been discovered and are present in all nucleated cells in our body. Like other essential organ of the body, the skin also has cycles that are informed by this master regulator. In addition, skin cells have peripheral clocks that can function autonomously. First described in 2000 for skin, this review summarizes some important aspects of a rapidly growing body of research in circadian and ultradian (an oscillation that repeats multiple times during a 24 h period) cutaneous rhythms, including clock mechanisms, functional manifestations, and stimuli that entrain or disrupt normal cycling. Some specific relationships between disrupted clock signaling and consequences to skin health are discussed in more depth in the other invited articles in this IJMS issue on Sleep, Circadian Rhythm and Skin. PMID:27231897

  6. Resting state Rolandic mu rhythms are related to activity of sympathetic component of autonomic nervous system in healthy humans.

    PubMed

    Triggiani, Antonio Ivano; Valenzano, Anna; Del Percio, Claudio; Marzano, Nicola; Soricelli, Andrea; Petito, Annamaria; Bellomo, Antonello; Başar, Erol; Mundi, Ciro; Cibelli, Giuseppe; Babiloni, Claudio

    2016-05-01

    We tested the hypothesis of a relationship between heart rate variability (HRV) and Rolandic mu rhythms in relaxed condition of resting state. Resting state eyes-closed electroencephalographic (EEG) and electrocardiographic (ECG) data were recorded (10-20 System) in 42 healthy adults. EEG rhythms of interest were high-frequency alpha (10.5-13Hz) and low-frequency beta (13-20Hz), which are supposed to form Rolandic mu rhythms. Rolandic and occipital (control) EEG sources were estimated by LORETA software. Results showed a statistically significant (p<0.05, corrected) negative correlation across all subjects between Rolandic cortical sources of low-frequency beta rhythms and the low-frequency band power (LF, 0.04-0.15Hz) of tachogram spectrum as an index of HRV. The lower the amplitude of Rolandic sources of low-frequency beta rhythms (as a putative sign of activity of somatomotor cortex), the higher the LF band power of tachogram spectrum (as a putative sign of sympathetic activity). This effect was specific as there was neither a similar correlation between these EEG rhythms and high-frequency band power of tachogram spectrum (as a putative sign of parasympathetic vagal activity) neither between occipital sources of low-frequency beta rhythms (as a putative sign of activity of visual cortex) and LF band power of tachogram spectrum. These results suggest that Rolandic low-frequency beta rhythms are related to sympathetic activity regulating heart rate, as a dynamic neurophysiologic oscillatory mechanism sub-serving the interaction between brain neural populations involved in somatomotor control and brain neural populations regulating ANS signals to heart for on-going homeostatic adaptations. PMID:25660308

  7. Electrophysiological actions of somatostatin on the atrioventricular junction in sinus rhythm and reentry tachycardia.

    PubMed Central

    Webb, S C; Krikler, D M; Hendry, W G; Adrian, T E; Bloom, S R

    1986-01-01

    Because somatostatin, a neuroregulatory peptide, is found in abundance in the atria and atrioventricular node, its electrophysiological and antiarrhythmic properties were compared with those of verapamil in ten patients with paroxysmal atrioventricular tachycardia. During sinus rhythm, intravenous somatostatin slowed the heart rate whereas verapamil increased it. Though both agents prolonged atrioventricular conduction time and refractoriness, verapamil was more potent. They were equally effective at terminating reentry atrioventricular tachycardia, restoring sinus rhythm in six of seven patients. Whereas verapamil consistently blocked conduction in the atrioventricular node, somatostatin usually induced ventricular extrasystoles at the time of conversion. Somatostatin may have physiological importance in the neurohumoral control of cardiac impulse formation and conduction. PMID:2875723

  8. Comparison of circadian rhythms in male and female humans

    NASA Technical Reports Server (NTRS)

    Winget, C. M.; Deroshia, C. W.; Vernikos-Danellis, J.; Rosenblatt, W. S.; Hetherington, N. W.

    1977-01-01

    Heart rate (HR) and rectal temperature (RT) data were obtained from 12 female and 27 male subjects. The subjects were housed in a facility where the environment was controlled. Human male and female RT and HR exhibit a circadian rhythm with an excursion of about 1.2 C and 30 beats/min, respectively. The acrophases, amplitudes, and level crossings are only slightly different between the sexes. The male HR and RT circadian wave forms are more stable than those of the females. However, the actual RT and HR of males were always lower than that of females at all time points around the clock. The HR during sleep in females is 15 per cent below the daily mean heart rate and in males, 22 per cent.

  9. Modality effects in rhythm processing: Auditory encoding of visual rhythms is neither obligatory nor automatic.

    PubMed

    McAuley, J Devin; Henry, Molly J

    2010-07-01

    Modality effects in rhythm processing were examined using a tempo judgment paradigm, in which participants made speeding-up or slowing-down judgments for auditory and visual sequences. A key element of stimulus construction was that the expected pattern of tempo judgments for critical test stimuli depended on a beat-based encoding of the sequence. A model-based measure of degree of beat-based encoding computed from the pattern of tempo judgments revealed greater beat sensitivity for auditory rhythms than for visual rhythms. Visual rhythms with prior auditory exposure were more likely to show a pattern of tempo judgments similar to that for auditory rhythms than were visual rhythms without prior auditory exposure, but only for a beat period of 600 msec. Slowing down the rhythms eliminated the effect of prior auditory exposure on visual rhythm processing. Taken together, the findings in this study support the view that auditory rhythms demonstrate an advantage over visual rhythms in beat-based encoding and that the auditory encoding of visual rhythms can be facilitated with prior auditory exposure, but only within a limited temporal range. The broad conclusion from this research is that "hearing visual rhythms" is neither obligatory nor automatic, as was previously claimed by Guttman, Gilroy, and Blake (2005). PMID:20601718

  10. Effects of acetylcholinesterase inhibitors and memantine on resting-state electroencephalographic rhythms in Alzheimer's disease patients.

    PubMed

    Babiloni, Claudio; Del Percio, Claudio; Bordet, Regis; Bourriez, Jean-Luis; Bentivoglio, Marina; Payoux, Pierre; Derambure, Philippe; Dix, Sophie; Infarinato, Francesco; Lizio, Roberta; Triggiani, Antonio Ivano; Richardson, Jill C; Rossini, Paolo M

    2013-05-01

    Acetylcholinesterase inhibitors (AChEIs) are the most widely used symptomatic treatment for mild to severe Alzheimer's disease (AD) patients, while N-methyl-d-aspartic acid (NMDA) receptor antagonist memantine is licensed for use in moderate to severe AD patients. In this article, the effect of these compounds on resting state eyes-closed electroencephalographic (EEG) rhythms in AD patients is reviewed to form a knowledge platform for the European Innovative Medicine Initiative project "PharmaCog" (IMI Grant Agreement No. 115009) aimed at developing innovative translational models for drug testing in AD. Indeed, quite similar EEG experiments and the same kind of spectral data analysis can be performed in animal models of AD and in elderly individuals with prodromal or manifest AD. Several studies have shown that AChEIs affect both resting state EEG rhythms and cognitive functions in AD patients. After few weeks of successful treatment, delta (0-3 Hz) or theta (4-7 Hz) rhythms decrease, dominant alpha rhythms (8-10 Hz) increase, and cognitive functions slightly improve. Beneficial effects of these rhythms and cognitive functions were also found in AD responders to the long-term successful treatment (i.e. 6-12 months). In contrast, only one study has explored the long-term effects of memantine on EEG rhythms in AD patients, showing reduced theta rhythms. The present review enlightens the expected effects of AChEIs on resting state EEG rhythms in AD patients as promising EEG markers for the development of translational protocols both within the PharmaCog project and for wider use. PMID:23098644

  11. ACCF/AHA/ASE/ASNC/HFSA/HRS/SCAI/SCCT/SCMR/STS 2013 multimodality appropriate use criteria for the detection and risk assessment of stable ischemic heart disease: a report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, American Heart Association, American Society of Echocardiography, American Society of Nuclear Cardiology, Heart Failure Society of America, Heart Rhythm Society, Society for Cardiovascular Angiography and Interventions, Society of Cardiovascular Computed Tomography, Society for Cardiovascular Magnetic Resonance, and Society of Thoracic Surgeons.

    PubMed

    Ronan, Grace; Wolk, Michael J; Bailey, Steven R; Doherty, John U; Douglas, Pamela S; Hendel, Robert C; Kramer, Christopher M; Min, James K; Patel, Manesh R; Rosenbaum, Lisa; Shaw, Leslee J; Stainback, Raymond F; Allen, Joseph M; Brindis, Ralph G; Kramer, Christopher M; Shaw, Leslee J; Cerqueira, Manuel D; Chen, Jersey; Dean, Larry S; Fazel, Reza; Hundley, W Gregory; Itchhaporia, Dipti; Kligfield, Paul; Lockwood, Richard; Marine, Joseph Edward; McCully, Robert Benjamin; Messer, Joseph V; O'Gara, Patrick T; Shemin, Richard J; Wann, L Samuel; Wong, John B; Patel, Manesh R; Kramer, Christopher M; Bailey, Steven R; Brown, Alan S; Doherty, John U; Douglas, Pamela S; Hendel, Robert C; Lindsay, Bruce D; Min, James K; Shaw, Leslee J; Stainback, Raymond F; Wann, L Samuel; Wolk, Michael J; Allen, Joseph M

    2014-02-01

    The American College of Cardiology Foundation along with key specialty and subspecialty societies, conducted an appropriate use review of common clinical presentations for stable ischemic heart disease (SIHD) to consider use of stress testing and anatomic diagnostic procedures. This document reflects an updating of the prior Appropriate Use Criteria (AUC) published for radionuclide imaging (RNI), stress echocardiography (Echo), calcium scoring, coronary computed tomography angiography (CCTA), stress cardiac magnetic resonance (CMR), and invasive coronary angiography for SIHD. This is in keeping with the commitment to revise and refine the AUC on a frequent basis. A major innovation in this document is the rating of tests side by side for the same indication. The side-by-side rating removes any concerns about differences in indication or interpretation stemming from prior use of separate documents for each test. However, the ratings were explicitly not competitive rankings due to the limited availability of comparative evidence, patient variability, and range of capabilities available in any given local setting. The indications for this review are limited to the detection and risk assessment of SIHD and were drawn from common applications or anticipated uses, as well as from current clinical practice guidelines. Eighty clinical scenarios were developed by a writing committee and scored by a separate rating panel on a scale of 1-9, to designate Appropriate, May Be Appropriate, or Rarely Appropriate use following a modified Delphi process following the recently updated AUC development methodology. The use of some modalities of testing in the initial evaluation of patients with symptoms representing ischemic equivalents, newly diagnosed heart failure, arrhythmias, and syncope was generally found to be Appropriate or May Be Appropriate, except in cases where low pre-test probability or low risk limited the benefit of most testing except exercise electrocardiogram (ECG

  12. ACCF/AHA/ASE/ASNC/HFSA/HRS/SCAI/SCCT/SCMR/STS 2013 multimodality appropriate use criteria for the detection and risk assessment of stable ischemic heart disease: a report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, American Heart Association, American Society of Echocardiography, American Society of Nuclear Cardiology, Heart Failure Society of America, Heart Rhythm Society, Society for Cardiovascular Angiography and Interventions, Society of Cardiovascular Computed Tomography, Society for Cardiovascular Magnetic Resonance, and Society of Thoracic Surgeons.

    PubMed

    Wolk, Michael J; Bailey, Steven R; Doherty, John U; Douglas, Pamela S; Hendel, Robert C; Kramer, Christopher M; Min, James K; Patel, Manesh R; Rosenbaum, Lisa; Shaw, Leslee J; Stainback, Raymond F; Allen, Joseph M

    2014-02-01

    The American College of Cardiology Foundation along with key specialty and subspecialty societies, conducted an appropriate use review of common clinical presentations for stable ischemic heart disease (SIHD) to consider use of stress testing and anatomic diagnostic procedures. This document reflects an updating of the prior Appropriate Use Criteria (AUC) published for radionuclide imaging (RNI), stress echocardiography (Echo), calcium scoring, coronary computed tomography angiography (CCTA), stress cardiac magnetic resonance (CMR), and invasive coronary angiography for SIHD. This is in keeping with the commitment to revise and refine the AUC on a frequent basis. A major innovation in this document is the rating of tests side by side for the same indication. The side-by-side rating removes any concerns about differences in indication or interpretation stemming from prior use of separate documents for each test. However, the ratings were explicitly not competitive rankings due to the limited availability of comparative evidence, patient variability, and range of capabilities available in any given local setting. The indications for this review are limited to the detection and risk assessment of SIHD and were drawn from common applications or anticipated uses, as well as from current clinical practice guidelines. Eighty clinical scenarios were developed by a writing committee and scored by a separate rating panel on a scale of 1 to 9, to designate Appropriate, May Be Appropriate, or Rarely Appropriate use following a modified Delphi process following the recently updated AUC development methodology. The use of some modalities of testing in the initial evaluation of patients with symptoms representing ischemic equivalents, newly diagnosed heart failure, arrhythmias, and syncope was generally found to be Appropriate or May Be Appropriate, except in cases where low pre-test probability or low risk limited the benefit of most testing except exercise electrocardiogram

  13. Biological rhythms during residence in polar regions.

    PubMed

    Arendt, Josephine

    2012-05-01

    At Arctic and Antarctic latitudes, personnel are deprived of natural sunlight in winter and have continuous daylight in summer: light of sufficient intensity and suitable spectral composition is the main factor that maintains the 24-h period of human circadian rhythms. Thus, the status of the circadian system is of interest. Moreover, the relatively controlled artificial light conditions in winter are conducive to experimentation with different types of light treatment. The hormone melatonin and/or its metabolite 6-sulfatoxymelatonin (aMT6s) provide probably the best index of circadian (and seasonal) timing. A frequent observation has been a delay of the circadian system in winter. A skeleton photoperiod (2 × 1-h, bright white light, morning and evening) can restore summer timing. A single 1-h pulse of light in the morning may be sufficient. A few people desynchronize from the 24-h day (free-run) and show their intrinsic circadian period, usually >24 h. With regard to general health in polar regions, intermittent reports describe abnormalities in various physiological processes from the point of view of daily and seasonal rhythms, but positive health outcomes are also published. True winter depression (SAD) appears to be rare, although subsyndromal SAD is reported. Probably of most concern are the numerous reports of sleep problems. These have prompted investigations of the underlying mechanisms and treatment interventions. A delay of the circadian system with "normal" working hours implies sleep is attempted at a suboptimal phase. Decrements in sleep efficiency, latency, duration, and quality are also seen in winter. Increasing the intensity of ambient light exposure throughout the day advanced circadian phase and was associated with benefits for sleep: blue-enriched light was slightly more effective than standard white light. Effects on performance remain to be fully investigated. At 75°S, base personnel adapt the circadian system to night work within a week

  14. Gravitational considerations with animal rhythms

    NASA Technical Reports Server (NTRS)

    Wunder, C. C.

    1974-01-01

    As established in the laboratory and largely confirmed by others, simulated high-g environments influence growth and development of animals as small as or smaller than baby turtles, sometimes accelerating and sometimes decelerating these processes. High-g environments result in many functional changes or adjustments in feeding, metabolism, circulation, fluid balances, and structures for support, and influence life expectancy. An assembly of equipment suitable for measuring oxygen consumption of small mammals as influenced by chronic centrifugation and/or by day-night rhythms is discussed.

  15. Nonlinear and Stochastic Dynamics in the Heart

    PubMed Central

    Qu, Zhilin; Hu, Gang; Garfinkel, Alan; Weiss, James N.

    2014-01-01

    In a normal human life span, the heart beats about 2 to 3 billion times. Under diseased conditions, a heart may lose its normal rhythm and degenerate suddenly into much faster and irregular rhythms, called arrhythmias, which may lead to sudden death. The transition from a normal rhythm to an arrhythmia is a transition from regular electrical wave conduction to irregular or turbulent wave conduction in the heart, and thus this medical problem is also a problem of physics and mathematics. In the last century, clinical, experimental, and theoretical studies have shown that dynamical theories play fundamental roles in understanding the mechanisms of the genesis of the normal heart rhythm as well as lethal arrhythmias. In this article, we summarize in detail the nonlinear and stochastic dynamics occurring in the heart and their links to normal cardiac functions and arrhythmias, providing a holistic view through integrating dynamics from the molecular (microscopic) scale, to the organelle (mesoscopic) scale, to the cellular, tissue, and organ (macroscopic) scales. We discuss what existing problems and challenges are waiting to be solved and how multi-scale mathematical modeling and nonlinear dynamics may be helpful for solving these problems. PMID:25267872

  16. Phenotyping Circadian Rhythms in Mice.

    PubMed

    Eckel-Mahan, Kristin; Sassone-Corsi, Paolo

    2015-01-01

    Circadian rhythms take place with a periodicity of 24 hr, temporally following the rotation of the earth around its axis. Examples of circadian rhythms are the sleep/wake cycle, feeding, and hormone secretion. Light powerfully entrains the mammalian clock and assists in keeping animals synchronized to the 24-hour cycle of the earth by activating specific neurons in the "central pacemaker" of the brain, the suprachiasmatic nucleus. Absolute periodicity of an animal can deviate slightly from 24 hr as manifest when an animal is placed into constant dark or "free-running" conditions. Simple measurements of an organism's activity in free-running conditions reveal its intrinsic circadian period. Mice are a particularly useful model for studying circadian rhythmicity due to the ease of genetic manipulation, thus identifying molecular contributors to rhythmicity. Furthermore, their small size allows for monitoring locomotion or activity in their homecage environment with relative ease. Several tasks commonly used to analyze circadian periodicity and plasticity in mice are presented here including the process of entrainment, determination of tau (period length) in free-running conditions, determination of circadian periodicity in response to light disruption (e.g., jet lag studies), and evaluation of clock plasticity in non-24-hour conditions (T-cycles). Studying the properties of circadian periods such as their phase, amplitude, and length in response to photic perturbation, can be particularly useful in understanding how humans respond to jet lag, night shifts, rotating shifts, or other transient or chronic disruption of environmental surroundings. PMID:26331760

  17. Detecting and Correcting Speech Rhythm Errors

    ERIC Educational Resources Information Center

    Yurtbasi, Metin

    2015-01-01

    Every language has its own rhythm. Unlike many other languages in the world, English depends on the correct pronunciation of stressed and unstressed or weakened syllables recurring in the same phrase or sentence. Mastering the rhythm of English makes speaking more effective. Experiments have shown that we tend to hear speech as more rhythmical…

  18. The Incarnate Rhythm of Geometrical Knowing

    ERIC Educational Resources Information Center

    Bautista, Alfredo; Roth, Wolff-Michael

    2012-01-01

    Rhythm is a fundamental dimension of human nature at both biological and social levels. However, existing research literature has not sufficiently investigated its role in mathematical cognition and behavior. The purpose of this article is to bring the concept of "incarnate rhythm" into current discourses in the field of mathematical learning and…

  19. Quantifying Speech Rhythm Abnormalities in the Dysarthrias

    ERIC Educational Resources Information Center

    Liss, Julie M.; White, Laurence; Mattys, Sven L.; Lansford, Kaitlin; Lotto, Andrew J.; Spitzer, Stephanie M.; Caviness, John N.

    2009-01-01

    Purpose: In this study, the authors examined whether rhythm metrics capable of distinguishing languages with high and low temporal stress contrast also can distinguish among control and dysarthric speakers of American English with perceptually distinct rhythm patterns. Methods: Acoustic measures of vocalic and consonantal segment durations were…

  20. Accelerated idioventricular rhythm during flexible fiberoptic bronchoscopy

    SciTech Connect

    Borgeat, A.; Chiolero, R.; Mosimann, B.; Freeman, J.

    1987-03-01

    We report the case of a patient who developed severe hypoxemia and an unusual arrhythmia, accelerated idioventricular rhythm, during flexible fiberoptic bronchoscopy. Coronary artery disease was subsequently suspected despite an unremarkable history and physical examination, and confirmed by a thallium 201 imaging. The appearance of accelerated idioventricular rhythm during fiberoptic bronchoscopy should raise the possibility of underlying coronary artery disease.

  1. Circadian rhythms in myocardial metabolism and function

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Circadian rhythms in myocardial function and dysfunction are firmly established in both animal models and humans. For example, the incidence of arrhythmias and sudden cardiac death increases when organisms awaken. Such observations have classically been explained by circadian rhythms in neurohumoral...

  2. Diurnal rhythms of visual accommodation and blink responses - Implication for flight-deck visual standards

    NASA Technical Reports Server (NTRS)

    Murphy, M. R.; Randle, R. J.; Williams, B. A.

    1977-01-01

    Possible 24-h variations in accommodation responses were investigated. A recently developed servo-controlled optometer and focus stimulator were used to obtain monocular accommodation response data on four college-age subjects. No 24-h rhythm in accommodation was shown. Heart rate and blink rate also were measured and periodicity analysis showed a mean 24-h rhythm for both; however, blink rate periodograms were significant for only two of the four subjects. Thus, with the qualifications that college students were tested instead of pilots and that they performed monocular laboratory tasks instead of binocular flight-deck tasks, it is concluded that 24-h rhythms in accommodation responses need not be considered in setting visual standards for flight-deck tasks.

  3. Common Abnormal Heart Rhythm Linked to Cancer Risk

    MedlinePlus

    ... published online May 25 in the journal JAMA Cardiology . Dr. Emelia Benjamin is a professor of medicine ... University School of Medicine; May 25, 2016, JAMA Cardiology , online HealthDay Copyright (c) 2016 HealthDay . All rights ...

  4. Common Abnormal Heart Rhythm Linked to Cancer Risk

    MedlinePlus

    ... found an association and doesn't prove that atrial fibrillation causes cancer To use the sharing features on ... study suggests. "We found a significant relationship between atrial fibrillation and cancer," said lead researcher Dr. David Conen, ...

  5. Circadian Rhythm Disruption Promotes Lung Tumorigenesis.

    PubMed

    Papagiannakopoulos, Thales; Bauer, Matthew R; Davidson, Shawn M; Heimann, Megan; Subbaraj, Lakshmipriya; Bhutkar, Arjun; Bartlebaugh, Jordan; Vander Heiden, Matthew G; Jacks, Tyler

    2016-08-01

    Circadian rhythms are 24-hr oscillations that control a variety of biological processes in living systems, including two hallmarks of cancer, cell division and metabolism. Circadian rhythm disruption by shift work is associated with greater risk for cancer development and poor prognosis, suggesting a putative tumor-suppressive role for circadian rhythm homeostasis. Using a genetically engineered mouse model of lung adenocarcinoma, we have characterized the effects of circadian rhythm disruption on lung tumorigenesis. We demonstrate that both physiologic perturbation (jet lag) and genetic mutation of the central circadian clock components decreased survival and promoted lung tumor growth and progression. The core circadian genes Per2 and Bmal1 were shown to have cell-autonomous tumor-suppressive roles in transformation and lung tumor progression. Loss of the central clock components led to increased c-Myc expression, enhanced proliferation, and metabolic dysregulation. Our findings demonstrate that both systemic and somatic disruption of circadian rhythms contribute to cancer progression. PMID:27476975

  6. Atrial fibrillation in heart failure: catheter and surgical interventional therapies.

    PubMed

    Rabah, Ali; Wazni, Oussama

    2014-05-01

    Atrial fibrillation and heart failure commonly coexist in the same patient. Each may adversely affect the other. Atrial fibrillation leads to heart failure exacerbation, left ventricular function deterioration and an increase in thrombo-embolic risk. Therapeutic options targeting atrial fibrillation in heart failure patients include pharmacological and non-pharmacological means. Pharmacological therapy is directed at either rate control using nodal blocking agents or rhythm control using anti-arrhythmic agents, of which the options are limited in patients with heart failure. The landmark AF-CHF trial did not show any benefit of rhythm control strategy as opposed to rate control in patients with heart failure and atrial fibrillation. However, patients in this trial as well as in others used mostly amiodarone for rhythm control. This might have negated any positive effects of achieving normal sinus rhythm. Non-pharmacological therapy both for rate and rhythm control is appealing. This includes AV node ablation for rate control, catheter ablation of atrial fibrillation and surgical therapy of atrial fibrillation. This review will address non-pharmacologic treatment of AF in heart failure patients. PMID:24132645

  7. The multi-modality cardiac imaging approach to the Athlete's heart: an expert consensus of the European Association of Cardiovascular Imaging.

    PubMed

    Galderisi, Maurizio; Cardim, Nuno; D'Andrea, Antonello; Bruder, Oliver; Cosyns, Bernard; Davin, Laurent; Donal, Erwan; Edvardsen, Thor; Freitas, Antonio; Habib, Gilbert; Kitsiou, Anastasia; Plein, Sven; Petersen, Steffen E; Popescu, Bogdan A; Schroeder, Stephen; Burgstahler, Christof; Lancellotti, Patrizio

    2015-04-01

    The term 'athlete's heart' refers to a clinical picture characterized by a slow heart rate and enlargement of the heart. A multi-modality imaging approach to the athlete's heart aims to differentiate physiological changes due to intensive training in the athlete's heart from serious cardiac diseases with similar morphological features. Imaging assessment of the athlete's heart should begin with a thorough echocardiographic examination.Left ventricular (LV) wall thickness by echocardiography can contribute to the distinction between athlete's LV hypertrophy and hypertrophic cardiomyopathy (HCM). LV end-diastolic diameter becomes larger (>55 mm) than the normal limits only in end-stage HCM patients when the LV ejection fraction is <50%. Patients with HCM also show early impairment of LV diastolic function, whereas athletes have normal diastolic function.When echocardiography cannot provide a clear differential diagnosis, cardiac magnetic resonance (CMR) imaging should be performed.With CMR, accurate morphological and functional assessment can be made. Tissue characterization by late gadolinium enhancement may show a distinctive, non-ischaemic pattern in HCM and a variety of other myocardial conditions such as idiopathic dilated cardiomyopathy or myocarditis. The work-up of athletes with suspected coronary artery disease should start with an exercise ECG. In athletes with inconclusive exercise ECG results, exercise stress echocardiography should be considered. Nuclear cardiology techniques, coronary cardiac tomography (CCT) and/or CMR may be performed in selected cases. Owing to radiation exposure and the young age of most athletes, the use of CCT and nuclear cardiology techniques should be restricted to athletes with unclear stress echocardiography or CMR. PMID:25681828

  8. Prenatal Ethanol Exposure Alters Core Body Temperature and Corticosterone Rhythms in Adult Male Rats

    PubMed Central

    Handa, Robert J.; Zuloaga, Damian G.; McGivern, Robert F.

    2008-01-01

    Ethanol’s effects on the developing brain include alterations in morphological and biochemistry of the hypothalamus. In order to examine the potential functional consequences of ethanol’s interference with hypothalamic differentiation, we studied the long-term effects of prenatal ethanol exposure on basal circadian rhythms of core body temperature (CBT) and heart rate (HR). We also examined the late afternoon surge in corticosterone (CORT). CBT and HR rhythms were studied in separate groups of animals at 4 months, 8 months and 20 months of age. The normal late-afternoon rise in plasma corticosterone was examined in freely-moving male rats at 6 months of age via an indwelling right-atrial cannula. Results showed that the CBT circadian rhythm exhibited an earlier rise following the nadir of the rhythm in fetal alcohol exposed (FAE) males at all ages compared to controls. At 8 months of age, the amplitude of the CBT circadian rhythm in FAE males was significantly reduced to the level observed in controls at 20 months. No significant effects of prenatal ethanol exposure were observed on basal HR rhythm at any age. The diurnal rise in corticosterone secretion was blunted and prolonged in 6-month-old FAE males compared to controls. Both control groups exhibited a robust surge in corticosterone secretion around the onset of the dark phase of the light cycle, which peaked at 1930 hours. Instead, FAE males exhibited a linear rise beginning in mid afternoon, which peaked at 2130 hours. These results indicate that exposure to ethanol during the period of hypothalamic development can alter the long-term regulation of circadian rhythms in specific physiological systems. PMID:18047910

  9. Craniosacral rhythm: reliability and relationships with cardiac and respiratory rates.

    PubMed

    Hanten, W P; Dawson, D D; Iwata, M; Seiden, M; Whitten, F G; Zink, T

    1998-03-01

    Craniosacral rhythm (CSR) has long been the subject of debate, both over its existence and its use as a therapeutic tool in evaluation and treatment. Origins of this rhythm are unknown, and palpatory findings lack scientific support. The purpose of this study was to determine the intra- and inter-examiner reliabilities of the palpation of the rate of the CSR and the relationship between the rate of the CSR and the heart or respiratory rates of subjects and examiners. The rates of the CSR of 40 healthy adults were palpated twice by each of two examiners. The heart and respiratory rates of the examiners and the subjects were recorded while the rates of the subjects' CSR were palpated by the examiners. Intraclass correlation coefficients were calculated to determine the intra- and inter-examiner reliabilities of the palpation. Two multiple regression analyses, one for each examiner, were conducted to analyze the relationships between the rate of the CSR and the heart and respiratory rates of the subjects and the examiners. The intraexaminer reliability coefficients were 0.78 for examiner A and 0.83 for examiner B, and the interexaminer reliability coefficient was 0.22. The result of the multiple regression analysis for examiner A was R = 0.46 and adjusted R2 = 0.12 (p = 0.078) and for examiner B was R = 0.63 and adjusted R2 = 0.32 (p = 0.001). The highest bivariate correlation was found between the CSR and the subject's heart rate (r = 0.30) for examiner A and between the CSR and the examiner's heart rate (r = 0.42) for examiner B. The results indicated that a single examiner may be able to palpate the rate of the CSR consistently, if that is what we truly measured. It is possible that the perception of CSR is illusory. The rate of the CSR palpated by two examiners is not consistent. The results of the regression analysis of one examiner offered no validation to those of the other. It appears that a subject's CSR is not related to the heart or respiratory rates of the

  10. Blood pressure, pulse rate, and rhythm measurement using ionic polymer-metal composite sensors

    NASA Astrophysics Data System (ADS)

    Keshavarzi, Amid; Shahinpoor, Mohsen; Kim, Kwang J.; Lantz, Jeffrey W.

    1999-05-01

    The need for more enhanced blood pressure (BP), pulse rate and rhythm senors has given rise to the possibility of using ionic polymer-metal composites (IPMCs) sensors. In this study we propose to use the IPMC sensors to measure systolic and diastolic BP, pulse rate and rhythm. The proposed IPMC sensors take advantage of the endo-ionic mobility within the polymer- metal composite by converting normal and shear load inputs into an induced voltage output across the thickness of the IPMC sensor. The fabricated IPMC sensors are suitable to be installed on the inner surface of a cuff and, therefore, both systolic and diastolic BP, pulse rate, and rhythm can be measured. An added benefit is the ability of measuring 'pulse rhythm' which give a more amplified look at heart irregularities which a typical pulse rate sensor is unable to show. Our data shows IPMC sensors can produce consistent and reliable BP readings, pulse rate, and rhythm. Typically, a linear relationship between applied maximum load and induced maximum voltage was obtained. This result can be easily translated into good BP reading.

  11. Circadian rhythms: glucocorticoids and arthritis.

    PubMed

    Cutolo, Maurizio; Sulli, Alberto; Pizzorni, Carmen; Secchi, Maria Elena; Soldano, Stefano; Seriolo, Bruno; Straub, Rainer H; Otsa, Kati; Maestroni, Georges J

    2006-06-01

    Circadian rhythms are driven by biological clocks and are endogenous in origin. Therefore, circadian changes in the metabolism or secretion of endogenous glucocorticoids are certainly responsible in part for the time-dependent changes observed in the inflammatory response and arthritis. More recently, melatonin (MLT), another circadian hormone that is the secretory product of the pineal gland, has been found implicated in the time-dependent inflammatory reaction with effects opposite those of cortisol. Interestingly, cortisol and MLT show an opposite response to the light. The light conditions in the early morning have a strong impact on the morning cortisol peak, whereas MLT is synthesized in a strictly nocturnal pattern. Recently, a diurnal rhythmicity in healthy humans between cellular (Th1 type) or humoral (Th2 type) immune responses has been found and related to immunomodulatory actions of cortisol and MLT. The interferon (IFN)-gamma/interleukin (IL)-10 ratio peaked during the early morning and correlated negatively with plasma cortisol and positively with plasma MLT. Accordingly, the intensity of the arthritic pain varies consistently as a function of the hour of the day: pain is greater after waking up in the morning than in the afternoon or evening. The reduced cortisol and adrenal androgen secretion, observed during testing in rheumatoid arthritis (RA) patients not treated with glucocoticoids, should be clearly considered as a "relative adrenal insufficiency" in the presence of a sustained inflammatory process, and allows Th1 type cytokines to be produced in higher amounts during the late night. In conclusion, the right timing (early morning) for the glucocorticoid therapy in arthritis is fundamental and well justified by the circadian rhythms of the inflammatory mechanisms. PMID:16855156

  12. Phenotyping Circadian Rhythms in Mice

    PubMed Central

    Eckel-Mahan, Kristin; Sassone-Corsi, Paolo

    2015-01-01

    Circadian rhythms take place with a periodicity of twenty-four hours, temporally following the rotation of the earth around its axis. Examples of circadian rhythms are the sleep/wake cycle, feeding, and hormone secretion. Light powerfully entrains the mammalian clock and assists in keeping animals synchronized to the 24-hour cycle of the earth by activating specific neurons in the “central pacemaker” of the brain, the suprachiasmatic nucleus. Absolute periodicity of an animal can deviate slightly from 24 hours as manifest when an animal is placed into constant dark- or “free running”- conditions. Simple measurements of an organism's activity in free running conditions reveal its intrinsic circadian period. Mice are a particularly useful model for studying circadian rhythmicity due to the ease of genetic manipulation, thus identifying molecular contributors to rhythmicity. Furthermore, their small size allows for monitoring locomotion or activity in their home cage environment with relative ease. Several tasks commonly used to analyze circadian periodicity and plasticity in mice are outlined here including the process of entrainment, determination of tau (period length) in free running conditions, determination of circadian periodicity in response to light disruption (i.e. jet lag studies), and evaluation of clock plasticity in non-twenty-four hour conditions (T-cycles). Studying the properties of circadian periods such as their phase, amplitude, and length in response to photic perturbation, can be particularly useful in understanding how humans respond to jet lag, night shifts, rotating shifts, or other transient or chronic disruption of one's environmental surroundings. PMID:26331760

  13. Irregular Sleep-Wake Rhythm Disorder.

    PubMed

    Abbott, Sabra M; Zee, Phyllis C

    2015-12-01

    Irregular sleep-wake rhythm disorder is a circadian rhythm disorder characterized by multiple bouts of sleep within a 24-hour period. Patients present with symptoms of insomnia, including difficulty either falling or staying asleep, and daytime excessive sleepiness. The disorder is seen in a variety of individuals, ranging from children with neurodevelopmental disorders, to patients with psychiatric disorders, and most commonly in older adults with neurodegenerative disorders. Treatment of irregular sleep-wake rhythm disorder requires a multimodal approach aimed at strengthening circadian synchronizing agents, such as daytime exposure to bright light, and structured social and physical activities. In addition, melatonin may be useful in some patients. PMID:26568126

  14. Musical alexia for rhythm notation: a discrepancy between pitch and rhythm.

    PubMed

    Midorikawa, Akira; Kawamura, Mitsuru; Kezuka, Machiko

    2003-06-01

    In the process of reading music, the reading of rhythm and pitch might be differentiated, although there is no evidence of this to date. There have been cases of disorders restricted to the reading of pitch, but none in which the disorder has been restricted to the reading of rhythm. We present a case of musical alexia and agraphia with Wernicke's aphasia. An in-depth assessment of the subject's musical reading ability showed that her musical alexia was restricted to unfamiliar melodies. When a melody was divided into rhythm elements and pitch elements, pitch reading was preserved, but rhythm reading was severely disturbed. This is the first case reported of a disorder restricted to rhythm reading, and suggests the independence of rhythm reading and pitch reading. PMID:12925929

  15. The effect of restraining on the heart rate in guinea pigs

    NASA Technical Reports Server (NTRS)

    Mikiskova, H.

    1980-01-01

    The emotional effect of different applications of electrodes and the fixation for cariographic examination was investigated using guinea pigs. The effect of the stress is discussed in terms of heart rhythm and behavior.

  16. Sino-European Transcontinental Basic and Clinical High-Tech Acupuncture Studies—Part 1: Auricular Acupuncture Increases Heart Rate Variability in Anesthetized Rats

    PubMed Central

    Gao, Xin-Yan; Liu, Kun; Zhu, Bing; Litscher, Gerhard

    2012-01-01

    Evidence-based research concerning the effects of high-tech acupuncture on autonomic function was performed by two research teams from China and Austria. This study describes the first transcontinental teleacupuncture measurements in animals. Heart rate (HR) and heart rate variability (HRV) recordings in 10 male Sprague-Dawley anesthetized rats were performed under stable conditions in Beijing, China, and the data analysis was completed in Graz, Austria. The electrocardiograms (ECGs) were recorded by an HRV Medilog AR12 system during acupuncture of the ear and body (PC6 Neiguan, CV12 Zhongwan, ST36 Zusanli). The data were analyzed using specially adapted novel Austrian software. HR did not change significantly during any acupuncture stimulation in anesthetized rats (ear acupuncture, PC6, CV12, or ST36). Total HRV only changed significantly (P = 0.025) during auricular acupuncture (acupoint heart). The low-frequency/high-frequency ratio parameter decreased significantly (P = 0.03) during stimulation of ST36. This change was based on intensification of the related mechanism of blood pressure regulation that has been demonstrated in previous studies in humans. Modernization of acupuncture research performed as a collaboration between China and Austria has also been demonstrated. PMID:22454685

  17. CIRCADIAN RHYTHM REPROGRAMMING DURING LUNG INFLAMMATION

    PubMed Central

    Haspel, Jeffrey A.; Chettimada, Sukrutha; Shaik, Rahamthulla S.; Chu, Jen-Hwa; Raby, Benjamin A.; Cernadas, Manuela; Carey, Vincent; Process, Vanessa; Hunninghake, G. Matthew; Ifedigbo, Emeka; Lederer, James A.; Englert, Joshua; Pelton, Ashley; Coronata, Anna; Fredenburgh, Laura E.; Choi, Augustine M. K.

    2014-01-01

    Circadian rhythms are known to regulate immune responses in healthy animals, but it is unclear whether they persist during acute illnesses where clock gene expression is disrupted by systemic inflammation. Here, we use a genome-wide approach to investigate circadian gene and metabolite expression in the lungs of endotoxemic mice and find that novel cellular and molecular circadian rhythms are elicited in this setting. The endotoxin-specific circadian program exhibits unique features, including a divergent group of rhythmic genes and metabolites compared to the basal state and a distinct periodicity and phase distribution. At the cellular level endotoxin treatment also alters circadian rhythms of leukocyte counts within the lung in a bmal1-dependent manner, such that granulocytes rather than lymphocytes become the dominant oscillating cell type. Our results show that inflammation produces a complex reorganization of cellular and molecular circadian rhythms that are relevant to early events in lung injury. PMID:25208554

  18. Metrical perception of trisyllabic speech rhythms.

    PubMed

    Benadon, Fernando

    2014-01-01

    The perception of duration-based syllabic rhythm was examined within a metrical framework. Participants assessed the duration patterns of four-syllable phrases set within the stress structure XxxX (an Abercrombian trisyllabic foot). Using on-screen sliders, participants created percussive sequences that imitated speech rhythms and analogous non-speech monotone rhythms. There was a tendency to equalize the interval durations for speech stimuli but not for non-speech. Despite the perceptual regularization of syllable durations, different speech phrases were conceived in various rhythmic configurations, pointing to a diversity of perceived meters in speech. In addition, imitations of speech stimuli showed more variability than those of non-speech. Rhythmically skilled listeners exhibited lower variability and were more consistent with vowel-centric estimates when assessing speech stimuli. These findings enable new connections between meter- and duration-based models of speech rhythm perception. PMID:23417710

  19. Protecting the Melatonin Rhythm through Circadian Healthy Light Exposure

    PubMed Central

    Bonmati-Carrion, Maria Angeles; Arguelles-Prieto, Raquel; Martinez-Madrid, Maria Jose; Reiter, Russel; Hardeland, Ruediger; Rol, Maria Angeles; Madrid, Juan Antonio

    2014-01-01

    Currently, in developed countries, nights are excessively illuminated (light at night), whereas daytime is mainly spent indoors, and thus people are exposed to much lower light intensities than under natural conditions. In spite of the positive impact of artificial light, we pay a price for the easy access to light during the night: disorganization of our circadian system or chronodisruption (CD), including perturbations in melatonin rhythm. Epidemiological studies show that CD is associated with an increased incidence of diabetes, obesity, heart disease, cognitive and affective impairment, premature aging and some types of cancer. Knowledge of retinal photoreceptors and the discovery of melanopsin in some ganglion cells demonstrate that light intensity, timing and spectrum must be considered to keep the biological clock properly entrained. Importantly, not all wavelengths of light are equally chronodisrupting. Blue light, which is particularly beneficial during the daytime, seems to be more disruptive at night, and induces the strongest melatonin inhibition. Nocturnal blue light exposure is currently increasing, due to the proliferation of energy-efficient lighting (LEDs) and electronic devices. Thus, the development of lighting systems that preserve the melatonin rhythm could reduce the health risks induced by chronodisruption. This review addresses the state of the art regarding the crosstalk between light and the circadian system. PMID:25526564

  20. Spontaneous Group Synchronization of Movements and Respiratory Rhythms

    PubMed Central

    Vandoni, Matteo; Bernardi, Luciano

    2014-01-01

    We tested whether pre-assigned arm movements performed in a group setting spontaneously synchronized and whether synchronization extended to heart and respiratory rhythms. We monitored arm movements, respiration and electrocardiogram at rest and during spontaneous, music and metronome-associated arm-swinging. No directions were given on whether or how the arm swinging were to be synchronized between participants or with the external cues. Synchronization within 3 groups of 10 participants studied collectively was compared with pseudo-synchronization of 3 groups of 10 participants that underwent an identical protocol but in an individual setting. Motor synchronization was found to be higher in the collective groups than in the individuals for the metronome-associated condition. On a repetition of the protocol on the following day, motor synchronization in the collective groups extended to the spontaneous, un-cued condition. Breathing was also more synchronized in the collective groups than in the individuals, particularly at rest and in the music-associated condition. Group synchronization occurs without explicit instructions, and involves both movements and respiratory control rhythms. PMID:25216280

  1. An Artificial Vector Model for Generating Abnormal Electrocardiographic Rhythms

    PubMed Central

    Clifford, Gari D.; Nemati, Shamim; Sameni, Reza

    2010-01-01

    We present generalizations of our previously published artificial models for generating multi-channel ECG to provide simulations of abnormal cardiac rhythms. Using a three-dimensional vectorcardiogram (VCG) formulation, we generate the normal cardiac dipole for a patient using a sum of Gaussian kernels, fitted to real VCG recordings. Abnormal beats are specified either as perturbations to the normal dipole or as new dipole trajectories. Switching between normal and abnormal beat types is achieved using a first-order Markov chain. Probability transitions can be learned from real data or modeled by coupling to heart rate and sympathovagal balance. Natural morphology changes from beat-to-beat are incorporated by varying the angular frequency of the dipole as a function of the inter-beat (RR) interval. The RR interval time series is generated using our previously described model whereby time- and frequency-domain heart rate (HR) and heart rate variability characteristics can be specified. QT-HR hysteresis is simulated by coupling the Gaussian kernels associated with the T-wave in the model with a nonlinear factor related to the local HR (determined from the last n RR intervals). Morphology changes due to respiration are simulated by introducing a rotation matrix couple to the respiratory frequency. We demonstrate an example of the use of this model by simulating HR-dependent T-Wave Alternans (TWA) with and without phase-switching due to ectopy. Application of our model also reveals previously unreported effects of common TWA estimation methods. PMID:20308774

  2. Circadian rhythms in cardiac arrhythmias and opportunities for their chronotherapy.

    PubMed

    Portaluppi, Francesco; Hermida, Ramón C

    2007-08-31

    It is now well established that nearly all functions of the body, including those that influence the pharmacokinetics and pharmacodynamics of medications, exhibit significant 24-hour variation. The electrical properties of the heart as well as cardiac arrhythmias also vary as circadian rhythms, even though the suboptimal methods initially used for their investigation slowed their identification and thorough characterization. The application of continuous Holter monitoring of the electrical properties of the heart has revealed 24-hour variation in the occurrence of ventricular premature beats with the peak in events, in diurnally active persons, between 6 a.m. and noon. After the introduction of implantable cardioverter-defibrillators, ventricular tachycardia or fibrillation were also found to peak in the same period of the day. Even defibrillator energy requirements show circadian variation, thus supporting the need for a temporal awareness in the therapeutic approach to arrhythmias. Imbalanced autonomic tone, circulating levels of catecholamines, increased heart rate and blood pressure, all established determinants of cardiac arrhythmias, show circadian variations and underlie the genesis of the circadian pattern of cardiac arrhythmias. Arrhythmogenesis appears to be suppressed during nighttime sleep, and this can influence the evaluation of the efficacy of antiarrhythmic medications in relation to their administration time. Unfortunately, very few studies have been undertaken to assess the proper timing (chronotherapy) of antiarrhythmic medications as means to maximize efficacy and possibly reduce side effects. Further research in this field is warranted and could bring new insight and clinical advantage. PMID:17659808

  3. Biological Rhythms During Residence in Polar Regions

    PubMed Central

    2012-01-01

    At Arctic and Antarctic latitudes, personnel are deprived of natural sunlight in winter and have continuous daylight in summer: light of sufficient intensity and suitable spectral composition is the main factor that maintains the 24-h period of human circadian rhythms. Thus, the status of the circadian system is of interest. Moreover, the relatively controlled artificial light conditions in winter are conducive to experimentation with different types of light treatment. The hormone melatonin and/or its metabolite 6-sulfatoxymelatonin (aMT6s) provide probably the best index of circadian (and seasonal) timing. A frequent observation has been a delay of the circadian system in winter. A skeleton photoperiod (2 × 1-h, bright white light, morning and evening) can restore summer timing. A single 1-h pulse of light in the morning may be sufficient. A few people desynchronize from the 24-h day (free-run) and show their intrinsic circadian period, usually >24 h. With regard to general health in polar regions, intermittent reports describe abnormalities in various physiological processes from the point of view of daily and seasonal rhythms, but positive health outcomes are also published. True winter depression (SAD) appears to be rare, although subsyndromal SAD is reported. Probably of most concern are the numerous reports of sleep problems. These have prompted investigations of the underlying mechanisms and treatment interventions. A delay of the circadian system with “normal” working hours implies sleep is attempted at a suboptimal phase. Decrements in sleep efficiency, latency, duration, and quality are also seen in winter. Increasing the intensity of ambient light exposure throughout the day advanced circadian phase and was associated with benefits for sleep: blue-enriched light was slightly more effective than standard white light. Effects on performance remain to be fully investigated. At 75°S, base personnel adapt the circadian system to night work within

  4. Neuroanatomy of the Extended Circadian Rhythm System

    PubMed Central

    Morin, Lawrence P

    2012-01-01

    The suprachiasmatic nucleus (SCN), site of the primary clock in the circadian rhythm system, has three major afferent connections. The most important consists of a retinohypothalamic projection through which photic information, received by classical rod/cone photoreceptors and intrinsically photoreceptive retinal ganglion cells, gains access to the clock. This information influences phase and period of circadian rhythms. The two other robust afferent projections are the median raphe serotonergic pathway and the geniculohypothalamic (GHT), NPY-containing pathway from the thalamic intergeniculate leaflet (IGL). Beyond this simple framework, the number of anatomical routes that could theoretically be involved in rhythm regulation is enormous, with the SCN projecting to 15 regions and being directly innervated by about 35. If multisynaptic afferents to the SCN are included, the number expands to approximately brain 85 areas providing input to the SCN. The IGL, a known contributor to circadian rhythm regulation, has a still greater level of complexity. This nucleus connects abundantly throughout the brain (to approximately 100 regions) by pathways that are largely bilateral and reciprocal. Few of these sites have been evaluated for their contributions to circadian rhythm regulation, although most have a theoretical possibility of doing so via the GHT. The anatomy of IGL connections suggests that one of its functions may be regulation of eye movements during sleep. Together, neural circuits of the SCN and IGL are complex and interconnected. As yet, few have been tested with respect to their involvement in rhythm regulation. PMID:22766204

  5. Circadian rhythms and cancer chemotherapy.

    PubMed

    Wood, P A; Hrushesky, W J

    1996-01-01

    Temporal coordination of biologic processes with an approximately 24-h cycle (circadian) is common throughout the animal and plant kingdom and even in some prokaryotic organisms. In all organisms studied, the capability to keep biologic time is an inherited characteristic located intracellularly. These biological clocks anticipate and get the organism ready for regular environmental changes. This indicates both the ubiquity and the weight of the selective environmental pressure to keep time accurately. Several molecular strategies for biologic time keeping have apparently arisen independently several times throughout evolution. The anatomic, biochemical, and molecular mechanisms of the clock are in the process of being defined. This temporal organization at the cellular, organ, and organismic levels results in predictable differences in the capacity of plants, animals, and human beings to respond to therapeutic interventions administered at different times throughout important biologic cycles (e.g., circadian timed therapy). In the treatment of the cancer bearing host, circadian timing of surgery, anticancer drugs, radiation therapy, and biologic agents can result in improved toxicity profiles, enhanced tumor control, and improved host survival. The routine clinical application of such principles is facilitated by the availability of programmable drug delivery devices. Rhythm frequency ranges other than 24-h (e.g., low frequency: menstrual; high frequency: 10 to 120 min) may also be important to understanding health and disease and to designing successful therapy in diseases as diverse as cancer, infertility, and diabetes. PMID:8959371

  6. The role of feeding rhythm, adrenal hormones and neuronal inputs in synchronizing daily clock gene rhythms in the liver.

    PubMed

    Su, Yan; Cailotto, Cathy; Foppen, Ewout; Jansen, Remi; Zhang, Zhi; Buijs, Ruud; Fliers, Eric; Kalsbeek, Andries

    2016-02-15

    The master clock in the hypothalamic suprachiasmatic nucleus (SCN) is assumed to distribute rhythmic information to the periphery via neural, humoral and/or behavioral connections. Until now, feeding, corticosterone and neural inputs are considered important signals for synchronizing daily rhythms in the liver. In this study, we investigated the necessity of neural inputs as well as of the feeding and adrenal hormone rhythms for maintaining daily hepatic clock gene rhythms. Clock genes kept their daily rhythm when only one of these three signals was disrupted, or when we disrupted hepatic neuronal inputs together with the adrenal hormone rhythm or with the daily feeding rhythm. However, all clock genes studied lost their daily expression rhythm after simultaneous disruption of the feeding and adrenal hormone rhythm. These data indicate that either a daily rhythm of feeding or adrenal hormones should be present to synchronize clock gene rhythms in the liver with the SCN. PMID:26704081

  7. Monitoring chaos of cardiac rhythms

    SciTech Connect

    Mayer-Kress, G.

    1989-01-01

    Chaos theory provides a new paradigm in monitoring complexity changes in heart rate variability. Even in cases where the spectral analysis only shows broad band characteristics estimations of dimensional complexity parameters can show quantitative changes in the degree of chaos present in the interbeat interval dynamics. We introduce the concept of dimensional complexity as dynamical monitoring parameter and discuss its properties in connection with control data and data taken during cardiac arrest. Whereas dimensional complexity provides a quantitative indicator of overall chaotic behavior, recurrence plots allow direct visualization of recurrences in arbitrary high dimensional pattern-space. In combination these two methods from non-linear dynamics exemplify a new approach in the problem of heart rate monitoring and identification of precursors of cardiac arrest. Finally we mention a new method of chaotic control, by which selective and highly effective perturbations of nonlinear dynamical systems could be used for improved pacing patterns. 11 refs., 6 figs.

  8. [Ventricular pre-excitation revealed by idioventricular rhythm and large QRS tachycardias. Apropos of an operated case].

    PubMed

    Weissenburger, J; Dumoulin, P; Juliard, J M; Frank, R; Kessler, P; Michel, P L; Rozensztajn, L; Valty, J

    1983-06-01

    A 15 year old boy presented with palpitations of sudden onset and termination over a two month period. The heart was clinically and radiologically normal. The electrocardiogramme showed sinus rhythm with a short PR interval (0,11 sec) and narrow QRS complexes (0,08 sec) associated with an intermittent escape accelerated idioventricular rhythm (AIVR). During an attack of palpitations a regular tachycardia (250/min) with wide QRS complexes of the same configuration as those of the AIVR (left side delay). The diagnosis of ventricular tachycardia was retained. Endocavitary electrophysiological recording demonstrated preexcitation of the right ventricle associated with accelerated nodal conduction explaining the narrow QRS complexes in sinus rhythm. The wide complex tachycardias initiated and terminated by paired ventricular stimulation were identical to the spontaneous attacks and were attributed to an antidromic reciprocating rhythm. The hypothesis of a rhythm arising from the accessory pathway is suggested. This would explain the identical configuration of the QRS complexes of the AIVR and of the antidromic reciprocating-rhythm and the disappearance of the AIVR after surgical section of the accessory pathway. PMID:6414416

  9. Convergent Rhythm Generation from Divergent Cellular Mechanisms

    PubMed Central

    Rodriguez, Jason C.; Blitz, Dawn M.

    2013-01-01

    Different modulatory inputs commonly elicit distinct rhythmic motor patterns from a central pattern generator (CPG), but they can instead elicit the same pattern. We are determining the rhythm-generating mechanisms in this latter situation, using the gastric mill (chewing) CPG in the crab (Cancer borealis) stomatogastric ganglion, where stimulating the projection neuron MCN1 (modulatory commissural neuron 1) or bath applying CabPK (C. borealis pyrokinin) peptide elicits the same gastric mill motor pattern, despite configuring different gastric mill circuits. In both cases, the core rhythm generator includes the same reciprocally inhibitory neurons LG (lateral gastric) and Int1 (interneuron 1), but the pyloric (food-filtering) circuit pacemaker neuron AB (anterior burster) is additionally necessary only for CabPK rhythm generation. MCN1 drives this rhythm generator by activating in the LG neuron the modulator-activated inward current (IMI), which waxes and wanes periodically due to phasic feedback inhibition of MCN1 transmitter release. Each buildup of IMI enables the LG neuron to generate a self-terminating burst and thereby alternate with Int1 activity. Here we establish that CabPK drives gastric mill rhythm generation by activating in the LG neuron IMI plus a slowly activating transient, low-threshold inward current (ITrans-LTS) that is voltage, time, and Ca2+ dependent. Unlike MCN1, CabPK maintains a steady IMI activation, causing a subthreshold depolarization in LG that facilitates a periodic postinhibitory rebound burst caused by the regular buildup and decay of the availability of ITrans-LTS. Thus, different modulatory inputs can use different rhythm-generating mechanisms to drive the same neuronal rhythm. Additionally, the same ionic current (IMI) can play different roles under these different conditions, while different currents (IMI, ITrans-LTS) can play the same role. PMID:24227716

  10. Alpha-amylase circadian rhythm of young rat parotid gland: an endogenous rhythm with maternal coordination.

    PubMed

    Bellavía, S L; Sanz, E G; Sereno, R; Vermouth, N T

    1992-01-01

    The circadian rhythm of alpha-amylase, E.C. 3.2.1.1. alpha-1,4-glucan-4-glucanohydrolase) in the parotid glands of 25-day-old rats were studied under different experimental designs (fasting, reversed photoperiod, constant lighting conditions and treatment with reserpine and alpha-methyl-p-tyrosine). The rhythm of fasted rats did not change. There were modifications in the rhythm of rats submitted to a reversed photoperiod or treated with reserpine or alpha-methyl-p-tyrosine. The rhythm was present, with changes in the acrophase, in parotids of rats kept during their gestation and postnatal life in constant light or dark. Results suggest that the circadian rhythm of alpha-amylase in parotid gland of young rats is endogenous, synchronized by the photoperiod, and with maternal coordination. PMID:1610312

  11. Open heart surgery

    MedlinePlus

    ... Heart bypass surgery (coronary artery bypass graft - CABG) Heart transplant Heart valve surgery Hypoplastic left heart repair Minimally ... Heart bypass surgery Heart bypass surgery - minimally invasive Heart transplant Heart valve surgery Hypoplastic left heart syndrome Patent ...

  12. Stratification of complexity in congenital heart surgery: comparative study of the Risk Adjustment for Congenital Heart Surgery (RACHS-1) method, Aristotle basic score and Society of Thoracic Surgeons-European Association for Cardio- Thoracic Surgery (STS-EACTS) mortality score

    PubMed Central

    Cavalcanti, Paulo Ernando Ferraz; Sá, Michel Pompeu Barros de Oliveira; dos Santos, Cecília Andrade; Esmeraldo, Isaac Melo; Chaves, Mariana Leal; Lins, Ricardo Felipe de Albuquerque; Lima, Ricardo de Carvalho

    2015-01-01

    Objective To determine whether stratification of complexity models in congenital heart surgery (RACHS-1, Aristotle basic score and STS-EACTS mortality score) fit to our center and determine the best method of discriminating hospital mortality. Methods Surgical procedures in congenital heart diseases in patients under 18 years of age were allocated to the categories proposed by the stratification of complexity methods currently available. The outcome hospital mortality was calculated for each category from the three models. Statistical analysis was performed to verify whether the categories presented different mortalities. The discriminatory ability of the models was determined by calculating the area under the ROC curve and a comparison between the curves of the three models was performed. Results 360 patients were allocated according to the three methods. There was a statistically significant difference between the mortality categories: RACHS-1 (1) - 1.3%, (2) - 11.4%, (3)-27.3%, (4) - 50 %, (P<0.001); Aristotle basic score (1) - 1.1%, (2) - 12.2%, (3) - 34%, (4) - 64.7%, (P<0.001); and STS-EACTS mortality score (1) - 5.5 %, (2) - 13.6%, (3) - 18.7%, (4) - 35.8%, (P<0.001). The three models had similar accuracy by calculating the area under the ROC curve: RACHS-1- 0.738; STS-EACTS-0.739; Aristotle- 0.766. Conclusion The three models of stratification of complexity currently available in the literature are useful with different mortalities between the proposed categories with similar discriminatory capacity for hospital mortality. PMID:26107445

  13. Heart Attack

    MedlinePlus

    ... attack treatment works best when it's given right after symptoms occur. Prompt treatment of a heart attack can help prevent or limit damage to the heart and prevent sudden death. Call 9-1-1 Right Away A heart ...

  14. Heart attack

    MedlinePlus

    ... infarction; Non-ST-elevation myocardial infarction; NSTEMI; CAD-heart attack; Coronary artery disease-heart attack ... made up of cholesterol and other cells. A heart attack may occur when: A tear in the ...

  15. Heart Block

    MedlinePlus

    ... Block Explore Heart Block What Is... Electrical System & EKG Results Types Causes Who Is at Risk Signs & ... heart block. Doctors use a test called an EKG (electrocardiogram) to help diagnose heart block. This test ...

  16. Heart Anatomy

    MedlinePlus

    ... Incredible Machine Bonus poster (PDF) The Human Heart Anatomy Blood The Conduction System The Coronary Arteries The ... of the Leg Vasculature of the Torso Heart anatomy illustrations and animations for grades K-6. Heart ...

  17. Tracing the European course of cardiac resynchronization therapy from 2006 to 2008.

    PubMed

    Merkely, Bela; Roka, Attila; Kutyifa, Valentina; Boersma, Lucas; Leenhardt, Antoine; Lubinski, Andrzej; Oto, Ali; Proclemer, Alessandro; Brugada, Josep; Vardas, Panos E; Wolpert, Christian

    2010-05-01

    Cardiac resynchronization therapy (CRT) is a highly efficient treatment modality for patients with severe congestive heart failure and intraventricular dyssynchrony. However, the high individual cost and technical complexity of the implantation may limit its widespread utilization. The European Heart Rhythm Association (EHRA) launched a project to assess treatment of arrhythmias in all European Society of Cardiology member countries in order to have a platform for a progressive harmonization of arrhythmia treatment. As a result, two EHRA White Books have been published in 2008 and 2009 based on governmental, insurance, and professional society data. Our aim was to analyse the local differences in the utilization of CRT, based on these surveys. A total of 41 countries provided enough data to analyse years 2006-2008. Significant differences were found in the overall number of implantations and the growth rate between 2006 and 2008. Other contributing factors include local reimbursement of CRT, the existence of national guidelines, and a high number of conventional implantable cardioverter-defibrillator implantations, while GDP or healthcare spending has less effect. Focusing on improving these factors may increase the availability of CRT in countries where it is currently underutilized. PMID:20200017

  18. Microglia modulate respiratory rhythm generation and autoresuscitation.

    PubMed

    Lorea-Hernández, Jonathan-Julio; Morales, Teresa; Rivera-Angulo, Ana-Julia; Alcantara-Gonzalez, David; Peña-Ortega, Fernando

    2016-04-01

    Inflammation has been linked to the induction of apneas and Sudden Infant Death Syndrome, whereas proinflammatory mediators inhibit breathing when applied peripherally or directly into the CNS. Considering that peripheral inflammation can activate microglia in the CNS and that this cell type can directly release all proinflammatory mediators that modulate breathing, it is likely that microglia can modulate breathing generation. It might do so also in hypoxia, since microglia are sensitive to hypoxia, and peripheral proinflammatory conditions affect gasping generation and autoresuscitation. Here, we tested whether microglial activation or inhibition affected respiratory rhythm generation. By measuring breathing as well as the activity of the respiratory rhythm generator (the preBötzinger complex), we found that several microglial activators or inhibitors, applied intracisternally in vivo or in the recording bath in vitro, affect the generation of the respiratory rhythms both in normoxia and hypoxia. Furthermore, microglial activation with lipopolysaccharide affected the ability of the animals to autoresuscitate after hypoxic conditions, an effect that is blocked when lipopolysaccharide is co-applied with the microglial inhibitor minocycline. Moreover, we found that the modulation of respiratory rhythm generation induced in vitro by microglial inhibitors was reproduced by microglial depletion. In conclusion, our data show that microglia can modulate respiratory rhythm generation and autoresuscitation. PMID:26678570

  19. Daily Rhythms in Mobile Telephone Communication.

    PubMed

    Aledavood, Talayeh; López, Eduardo; Roberts, Sam G B; Reed-Tsochas, Felix; Moro, Esteban; Dunbar, Robin I M; Saramäki, Jari

    2015-01-01

    Circadian rhythms are known to be important drivers of human activity and the recent availability of electronic records of human behaviour has provided fine-grained data of temporal patterns of activity on a large scale. Further, questionnaire studies have identified important individual differences in circadian rhythms, with people broadly categorised into morning-like or evening-like individuals. However, little is known about the social aspects of these circadian rhythms, or how they vary across individuals. In this study we use a unique 18-month dataset that combines mobile phone calls and questionnaire data to examine individual differences in the daily rhythms of mobile phone activity. We demonstrate clear individual differences in daily patterns of phone calls, and show that these individual differences are persistent despite a high degree of turnover in the individuals' social networks. Further, women's calls were longer than men's calls, especially during the evening and at night, and these calls were typically focused on a small number of emotionally intense relationships. These results demonstrate that individual differences in circadian rhythms are not just related to broad patterns of morningness and eveningness, but have a strong social component, in directing phone calls to specific individuals at specific times of day. PMID:26390215

  20. Daily Rhythms in Mobile Telephone Communication

    PubMed Central

    Aledavood, Talayeh; López, Eduardo; Roberts, Sam G. B.; Reed-Tsochas, Felix; Moro, Esteban; Dunbar, Robin I. M.; Saramäki, Jari

    2015-01-01

    Circadian rhythms are known to be important drivers of human activity and the recent availability of electronic records of human behaviour has provided fine-grained data of temporal patterns of activity on a large scale. Further, questionnaire studies have identified important individual differences in circadian rhythms, with people broadly categorised into morning-like or evening-like individuals. However, little is known about the social aspects of these circadian rhythms, or how they vary across individuals. In this study we use a unique 18-month dataset that combines mobile phone calls and questionnaire data to examine individual differences in the daily rhythms of mobile phone activity. We demonstrate clear individual differences in daily patterns of phone calls, and show that these individual differences are persistent despite a high degree of turnover in the individuals’ social networks. Further, women’s calls were longer than men’s calls, especially during the evening and at night, and these calls were typically focused on a small number of emotionally intense relationships. These results demonstrate that individual differences in circadian rhythms are not just related to broad patterns of morningness and eveningness, but have a strong social component, in directing phone calls to specific individuals at specific times of day. PMID:26390215

  1. Mu rhythm desynchronization by tongue thrust observation

    PubMed Central

    Sakihara, Kotoe; Inagaki, Masumi

    2015-01-01

    We aimed to investigate the mu rhythm in the sensorimotor area during tongue thrust observation and to obtain an answer to the question as to how subtle non-verbal orofacial movement observation activates the sensorimotor area. Ten healthy volunteers performed finger tap execution, tongue thrust execution, and tongue thrust observation. The electroencephalogram (EEG) was recorded from 128 electrodes placed on the scalp, and regions of interest were set at sensorimotor areas. The event-related desynchronization (ERD) and event-related synchronization (ERS) for the mu rhythm (8–13 Hz) and beta (13−25 Hz) bands were measured. Tongue thrust observation induced mu rhythm ERD, and the ERD was detected at the left hemisphere regardless whether the observed tongue thrust was toward the left or right. Mu rhythm ERD was also recorded during tongue thrust execution. However, temporal analysis revealed that the ERD associated with tongue thrust observation preceded that associated with execution by approximately 2 s. Tongue thrust observation induces mu rhythm ERD in sensorimotor cortex with left hemispheric dominance. PMID:26441599

  2. Heart attack

    MedlinePlus

    ... a heart attack take part in a cardiac rehabilitation program. ... al. eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine . 10th ed. Philadelphia, PA: Elsevier Saunders; 2014: ...

  3. Circadian Rhythm Disruption Was Observed in Hand, Foot, and Mouth Disease Patients

    PubMed Central

    Zhu, Yu; Jiang, Zhou; Xiao, Guoguang; Cheng, Suting; Wen, Yang; Wan, Chaomin

    2015-01-01

    Abstract Hand, foot, and mouth disease (HFMD) with central nerve system complications may rapidly progress to fulminated cardiorespiratory failure, with higher mortality and worse prognosis. It has been reported that circadian rhythms of heart rate (HR) and respiratory rate are useful in predicting prognosis of severe cardiovascular and neurological diseases. The present study aims to investigate the characteristics of the circadian rhythms of HR, respiratory rate, and temperature in HFMD patients with neurological complications. Hospitalized HFMD patients including 33 common cases (common group), 61 severe cases (severe group), and 9 critical cases (critical group) were contrasted retrospectively. Their HR, respiratory rate, and temperatures were measured every 4 hours during the first 48-hour in the hospital. Data were analyzed with the least-squares fit of a 24-hour cosine function by the single cosinor and population-mean cosinor method. Results of population-mean cosinor analysis demonstrated that the circadian rhythm of HR, respiratory rate, and temperature was present in the common and severe group, but absent in the critical group. The midline-estimating statistic of rhythm (MESOR) (P = 0.016) and acrophase (P < 0.01) of temperature and respiratory rate were significantly different among 3 groups. But no statistical difference of amplitude in temperature and respiratory rate was observed among the 3 groups (P = 0.14). MESOR value of HR (P < 0.001) was significantly different in 3 groups. However, amplitude and acrophase revealed no statistical difference in circadian characteristics of HR among 3 groups. Compared with the common group, the MESOR of temperature and respiratory rate was significantly higher, and acrophase of temperature and respiratory rate was 2 hours ahead in the severe group, critical HFMD patients lost their population-circadian rhythm of temperature, HR, and respiratory rate. The high values of temperature and respiratory

  4. Circadian rhythm disruption was observed in hand, foot, and mouth disease patients.

    PubMed

    Zhu, Yu; Jiang, Zhou; Xiao, Guoguang; Cheng, Suting; Wen, Yang; Wan, Chaomin

    2015-03-01

    Hand, foot, and mouth disease (HFMD) with central nerve system complications may rapidly progress to fulminated cardiorespiratory failure, with higher mortality and worse prognosis. It has been reported that circadian rhythms of heart rate (HR) and respiratory rate are useful in predicting prognosis of severe cardiovascular and neurological diseases. The present study aims to investigate the characteristics of the circadian rhythms of HR, respiratory rate, and temperature in HFMD patients with neurological complications. Hospitalized HFMD patients including 33 common cases (common group), 61 severe cases (severe group), and 9 critical cases (critical group) were contrasted retrospectively. Their HR, respiratory rate, and temperatures were measured every 4 hours during the first 48-hour in the hospital. Data were analyzed with the least-squares fit of a 24-hour cosine function by the single cosinor and population-mean cosinor method. Results of population-mean cosinor analysis demonstrated that the circadian rhythm of HR, respiratory rate, and temperature was present in the common and severe group, but absent in the critical group. The midline-estimating statistic of rhythm (MESOR) (P = 0.016) and acrophase (P < 0.01) of temperature and respiratory rate were significantly different among 3 groups. But no statistical difference of amplitude in temperature and respiratory rate was observed among the 3 groups (P = 0.14). MESOR value of HR (P < 0.001) was significantly different in 3 groups. However, amplitude and acrophase revealed no statistical difference in circadian characteristics of HR among 3 groups. Compared with the common group, the MESOR of temperature and respiratory rate was significantly higher, and acrophase of temperature and respiratory rate was 2 hours ahead in the severe group, critical HFMD patients lost their population-circadian rhythm of temperature, HR, and respiratory rate. The high values of temperature and respiratory rate for

  5. Genetic Basis of Human Circadian Rhythm Disorders

    PubMed Central

    Jones, Christopher R.; Huang, Angela L.; Ptáček, Louis J.; Fu, Ying-Hui

    2012-01-01

    Circadian rhythm disorders constitute a group of phenotypes that usually present as altered sleep-wake schedules. Until a human genetics approach was applied to investigate these traits, the genetic components regulating human circadian rhythm and sleep behaviors remained mysterious. Steady advances in the last decade have dramatically improved our understanding of the genes involved in circadian rhythmicity and sleep regulation. Finding these genes presents new opportunities to use a wide range of approaches, including in vitro molecular studies and in vivo animal modeling, to elevate our understanding of how sleep and circadian rhythms are regulated and maintained. Ultimately, this knowledge will reveal how circadian and sleep disruption contribute to various ailments and shed light on how best to maintain and recover good health. PMID:22849821

  6. Adjustment of sleep and the circadian temperature rhythm after flights across nine time zones

    NASA Technical Reports Server (NTRS)

    Gander, Philippa H.; Myhre, Grete; Graeber, R. Curtis; Lauber, John K.; Andersen, Harald T.

    1989-01-01

    The adjustment of sleep-wake patterns and the circadian temperature rhythm was monitored in nine Royal Norwegian Airforce volunteers operating P-3 aircraft during a westward training deployment across nine time zones. Subjects recorded all sleep and nap times, rated nightly sleep quality, and completed personality inventories. Rectal temperature, heart rate, and wrist activity were continuously monitored. Adjustment was slower after the return eastward flight than after the outbound westward flight. The eastward flight produced slower readjustment of sleep timing to local time and greater interindividual variability in the patterns of adjustment of sleep and temperature. One subject apparently exhibited resynchronization by partition, with the temperature rhythm undergoing the reciprocal 15-h delay. In contrast, average heart rates during sleep were significantly elevated only after westward flight. Interindividual differences in adjustment of the temperature rhythm were correlated with some of the personality measures. Larger phase delays in the overall temperature waveform (as measured on the 5th day after westward flight) were exhibited by extraverts, and less consistently by evening types.

  7. Hemodynamic variables during exercise in childhood and resting systolic blood pressure levels 6 years later in adolescence: the European Youth Heart Study.

    PubMed

    Grøntved, A; Brage, S; Møller, N C; Kristensen, P L; Wedderkopp, N; Froberg, K; Andersen, L B

    2011-10-01

    The aim of this study was to analyze whether systolic blood pressure (SBP), heart rate (HR) and rate pressure product (RPP) during exercise in childhood can predict resting SBP levels in adolescence independent of resting SBP and conventional cardiovascular risk factors. We studied this in a sample of Danish children followed longitudinally for 6 years. The study comprised 226 children randomly sampled at age 9, who had their blood pressure and HR measured during ergometer exercise to exhaustion and was reassessed in adolescence. SBP and RPP during exercise in stage two of the test were positively associated with future resting SBP, independent of resting SBP in childhood (P=0.045 and P=0.013, respectively). After additional adjustment for conventional cardiovascular risk factors the associations with SBP and RPP during stage two on future resting SBP only slightly materially change, although only RPP remained significant (P=0.059 and P=0.012, respectively). No significant independent associations were observed for HR during exercise, but associations were in the same direction. Our results supports that measuring SBP and RPP, during a standard acute ergometer exercise test in children, improves the prediction of future SBP levels during rest in adolescence independent of resting SBP and conventional cardiovascular risk factors. PMID:21068765

  8. Heart Attack

    MedlinePlus

    ... have a heart attack. About half of them die. Many people have permanent heart damage or die because they don't get help immediately. It's ... few hours causes the affected heart muscle to die. NIH: National Heart, Lung, and Blood Institute

  9. Heart Transplantation

    MedlinePlus

    A heart transplant removes a damaged or diseased heart and replaces it with a healthy one. The healthy heart comes from a donor who has died. It is the last resort for people with heart failure when all other treatments have failed. The ...

  10. Heart Diseases

    MedlinePlus

    ... you're like most people, you think that heart disease is a problem for others. But heart disease is the number one killer in the ... of disability. There are many different forms of heart disease. The most common cause of heart disease ...

  11. Heart Diseases

    MedlinePlus

    ... re like most people, you think that heart disease is a problem for others. But heart disease is the number one killer in the U.S. ... disability. There are many different forms of heart disease. The most common cause of heart disease is ...

  12. Management of the hypertensive patient with elevated heart rate: Statement of the Second Consensus Conference endorsed by the European Society of Hypertension.

    PubMed

    Palatini, Paolo; Rosei, Enrico Agabiti; Casiglia, Edoardo; Chalmers, John; Ferrari, Roberto; Grassi, Guido; Inoue, Teruo; Jelakovic, Bojan; Jensen, Magnus T; Julius, Stevo; Kjeldsen, Sverre E; Mancia, Giuseppe; Parati, Gianfranco; Pauletto, Paolo; Stella, Andrea; Zanchetti, Alberto

    2016-05-01

    In June 2015, a panel of experts gathered in a consensus conference to plan updating recommendations on the management of the hypertensive patient with elevated heart rate (HR), previously released in 2006. The issues examined during that meeting and further discussed by the participants during the following months involved the assessment of HR, the relevance of HR as a cardiovascular risk factor, the definition of tachycardia and the treatment of the hypertensive patient with high HR. For the measurement of resting HR the panel experts recommended that scientific investigations focusing on HR should report information on length of resting period before measurement, information about temperature and environment, method of measurement, duration of measurement, number of readings, time interval between measurements, body position and type of observer. According to the panellists there is convincing evidence that HR is an important risk factor for cardiovascular disease and they suggest to routinely include HR measurement in the assessment of the hypertensive patient. Regarding the definition of tachycardia, the panellists acknowledged that in the absence of convincing data any threshold used to define tachycardia is arbitrary. Similarly, as there are no outcome studies of HR lowering in tachycardia hypertension, the panellists could not make practical therapeutic suggestions for the management of such patients. However, the experts remarked that absence of evidence does not mean evidence against the importance of tachycardia as a risk factor for cardiovascular disease and that long-term exposure to a potentially important risk factor may impair the patient's prognosis. The main aims of the present document are to alert researchers and physicians about the importance of measuring HR in hypertensive patients, and to stimulate research to clarify unresolved issues. PMID:26982382

  13. Monkey Lipsmacking Develops Like the Human Speech Rhythm

    ERIC Educational Resources Information Center

    Morrill, Ryan J.; Paukner, Annika; Ferrari, Pier F.; Ghazanfar, Asif A.

    2012-01-01

    Across all languages studied to date, audiovisual speech exhibits a consistent rhythmic structure. This rhythm is critical to speech perception. Some have suggested that the speech rhythm evolved "de novo" in humans. An alternative account--the one we explored here--is that the rhythm of speech evolved through the modification of rhythmic facial…

  14. Perceptual Tests of Rhythmic Similarity: I. Mora Rhythm

    ERIC Educational Resources Information Center

    Murty, Lalita; Otake, Takashi; Cutler, Anne

    2007-01-01

    Listeners rely on native-language rhythm in segmenting speech; in different languages, stress-, syllable- or mora-based rhythm is exploited. The rhythmic similarity hypothesis holds that where two languages have similar rhythm, listeners of each language should segment their own and the other language similarly. Such similarity in listening was…

  15. The Features and Training of English Stress and Rhythm

    ERIC Educational Resources Information Center

    Cai, Cui-yun

    2008-01-01

    In second language learning, to possess a perfect pronunciation, the importance of stress and rhythm should not be ignored. This articles explores the nature of sentence and word stress as well as rhythm, thus putting forward some feasible ways of training and acquiring a good English stress and rhythm in EFLT (English as Foreign Language…

  16. Does Melody Assist in the Reproduction of Novel Rhythm Patterns?

    ERIC Educational Resources Information Center

    Kinney, Daryl W.; Forsythe, Jere L.

    2013-01-01

    We examined music education majors' ability to reproduce rhythmic stimuli presented in melody and rhythm only conditions. Participants reproduced rhythms of two-measure music examples by immediately echo-performing through a method of their choosing (e.g., clapping, tapping, vocalizing). Forty examples were presented in melody and rhythm only…

  17. The Rhythm of Perception: Entrainment to Acoustic Rhythms Induces Subsequent Perceptual Oscillation.

    PubMed

    Hickok, Gregory; Farahbod, Haleh; Saberi, Kourosh

    2015-07-01

    Acoustic rhythms are pervasive in speech, music, and environmental sounds. Recent evidence for neural codes representing periodic information suggests that they may be a neural basis for the ability to detect rhythm. Further, rhythmic information has been found to modulate auditory-system excitability, which provides a potential mechanism for parsing the acoustic stream. Here, we explored the effects of a rhythmic stimulus on subsequent auditory perception. We found that a low-frequency (3 Hz), amplitude-modulated signal induces a subsequent oscillation of the perceptual detectability of a brief nonperiodic acoustic stimulus (1-kHz tone); the frequency but not the phase of the perceptual oscillation matches the entrained stimulus-driven rhythmic oscillation. This provides evidence that rhythmic contexts have a direct influence on subsequent auditory perception of discrete acoustic events. Rhythm coding is likely a fundamental feature of auditory-system design that predates the development of explicit human enjoyment of rhythm in music or poetry. PMID:25968248

  18. The rhythm of retinoids in the brain

    PubMed Central

    Ransom, Jemma; Morgan, Peter J; McCaffery, Peter J; Stoney, Patrick N

    2014-01-01

    The retinoids are a family of compounds that in nature are derived from vitamin A or pro-vitamin A carotenoids. An essential part of the diet for mammals, vitamin A has long been known to be essential for many organ systems in the adult. More recently, however, they have been shown to be necessary for function of the brain and new discoveries point to a central role in processes ranging from neuroplasticity to neurogenesis. Acting in several regions of the central nervous system including the eye, hippocampus and hypothalamus, one common factor in its action is control of biological rhythms. This review summarizes the role of vitamin A in the brain; its action through the metabolite retinoic acid via specific nuclear receptors, and the regulation of its concentration through controlled synthesis and catabolism. The action of retinoic acid to regulate several rhythms in the brain and body, from circadian to seasonal, is then discussed to finish with the importance of retinoic acid in the regular pattern of sleep. We review the role of vitamin A and retinoic acid (RA) as mediators of rhythm in the brain. In the suprachiasmatic nucleus and hippocampus they control expression of circadian clock genes while in the cortex retinoic acid is required for delta oscillations of sleep. Retinoic acid is also central to a second rhythm that keeps pace with the seasons, regulating function in the hypothalamus and pineal gland. PMID:24266881

  19. Characterization of neurospora circadian rhythms in space

    NASA Technical Reports Server (NTRS)

    Ferraro, James S.

    1987-01-01

    To determine whether the circadian rhythm of conidiation in neurospora crassa is endogenously derived or is driven by some geophysical time cue, an experiment was conducted on space shuttle flight STS-9, where inoculated race tubes were exposed to the microgravity environment of space. The results demonstated that the rhythm can persist in space. However, there were several minor alterations noted; an increase in the period of the oscillation and the variability of the growth rate and a diminished rhythm amplitude, which eventually damped out in 25% of the flight tubes. On day seven of the flight, the tubes were exposed to light while their growth fronts were marked. It appears that some aspects of this marking process reinstated a robust rhythm in all the tubes which continued throughout the remainder of the flight. It was hypothesized that the damping found prior to the marking procedure on STS-9 may have been a result of the hypergravity pulse of launch and not due to the microgravity of the orbital lab; furthermore, that the marking procedure, by exposing the samples to light, had reinstated rhythmicity. To test this, an investigation was conducted into the effects of acute and chronic exposure to hypergravity.

  20. Neuroscience: A Sleep Rhythm with Multiple Facets.

    PubMed

    Koo, Ping Chai; Marshall, Lisa

    2016-09-12

    Sleep spindles were one of the first rhythms associated with learning and memory consolidation. Current research shows spindles can reflect features of trait and time-varying properties of neuroplasticity. A new study has now used feedback-controlled spindle frequency stimulation to show that sleep spindles modulate endogenous brain electric activity and behavior. PMID:27623266

  1. Environmental synchronizers of squirrel monkey circadian rhythms

    NASA Technical Reports Server (NTRS)

    Sulzman, F. M.; Fuller, C. A.; Moore-Ede, M. C.

    1977-01-01

    Various temporal signals in the environment were tested to determine if they could synchronize the circadian timing system of the squirrel monkey (Saimiri sciureus). The influence of cycles of light and dark, eating and fasting, water availability and deprivation, warm and cool temperature, sound and quiet, and social interaction and isolation on the drinking and activity rhythms of unrestrained monkeys was examined. In the absence of other time cues, 24-hr cycles of each of these potential synchronizers were applied for up to 3 wk, and the periods of the monkey's circadian rhythms were examined. Only light-dark cycles and cycles of food availability were shown to be entraining agents, since they were effective in determining the period and phase of the rhythmic variables. In the presence of each of the other environmental cycles, the monkey's circadian rhythms exhibited free-running periods which were significantly different from 24 hr with all possible phase relationships between the rhythms and the environmental cycles being examined.

  2. Circadian temperature rhythms of older people

    NASA Technical Reports Server (NTRS)

    Monk, T. H.; Buysse, D. J.; Reynolds, C. F. 3rd; Kupfer, D. J.; Houck, P. R.

    1995-01-01

    This collection of studies had the aim of exploring whether older (77+ years) men and women have circadian body temperature rhythms different from those of younger adults. A total of 20 older men and 28 older women were compared with either 22 young men or 14 middle-aged men in four protocols; all but the first protocol using a subset of the sample. The four protocols were: 1) 24 h, and 2) 72 h data collections on a normal laboratory routine (sleeping at night); 3) between 36 h and 153 h of field data collection at home; and 4) 36 h of a constant conditions routine (wakeful bedrest under temporal isolation) in the laboratory. There was some evidence for an age-related phase advance in temperature rhythm, especially for the older men on a normal routine, though this was not present in the constant conditions protocol, where 5 of the older subjects showed major delays in the timing of the body temperature trough (10:00 or later). There was no statistically significant evidence from any of the protocols that older subjects generally had lower temperature rhythm amplitudes than younger adults. Only when older men were compared with younger men in 24-h rhythm amplitude by simple t-test did any comparison involving amplitude achieve statistical significance (p < 0.05).

  3. Procedures for numerical analysis of circadian rhythms

    PubMed Central

    REFINETTI, ROBERTO; LISSEN, GERMAINE CORNÉ; HALBERG, FRANZ

    2010-01-01

    This article reviews various procedures used in the analysis of circadian rhythms at the populational, organismal, cellular and molecular levels. The procedures range from visual inspection of time plots and actograms to several mathematical methods of time series analysis. Computational steps are described in some detail, and additional bibliographic resources and computer programs are listed. PMID:23710111

  4. Emotion and Rhythm in Critical Learning Incidents

    ERIC Educational Resources Information Center

    Soini, Hannu; Flynn, Mark

    2005-01-01

    In this paper, we analyzed the descriptions of learning provided by 234 College of Education students from Finland and Canada and compared them with Whitehead's (1932/1962) epistemological theory of the rhythm of mental growth. The students were asked to "Give a concrete example of a situation in which you really learned something." The…

  5. [Circadian rhythm sleep disorders in psychiatric diseases].

    PubMed

    Bromundt, Vivien

    2014-11-01

    Circadian rhythm sleep disorders are prevalent among psychiatric patients. This is most probable due to a close relationship between functional disturbances of the internal clock, sleep regulation and mental health. Mechanisms on molecular level of the circadian clock and neurotransmitter signalling are involved in the development of both disorders. Moreover, circadian disorders and psychiatric diseases favour each other by accessory symptoms such as stress or social isolation. Actimetry to objectively quantify the rest-activity cycle and salivary melatonin profiles as marker for the circadian phase help to diagnose circadian rhythm sleep disorders in psychiatric patients. Chronotherapeutics such as bright light therapy, dark therapy, melatonin administration, and wake therapy are used to synchronise and consolidate circadian rhythms and help in the treatment of depression and other psychiatric disorders, but are still neglected in medicine. More molecular to behavioural research is needed for the understanding of the development of circadian disorders and their relationship to psychiatric illnesses. This will help to boost the awareness and treatment of circadian rhythm sleep disorders in psychiatry. PMID:25377290

  6. Circadian rhythm of gravitaxis in Euglena gracilis.

    PubMed

    Lebert, M; Porst, M; Hader, D P

    1999-09-01

    Euglena gracilis, a unicellular, photosynthetic flagellate is a model system for environmentally controlled behavioral reactions. One pronounced reaction is the orientation with respect to gravity. In synchronized cultures with no cell growth a distinct circadian rhythm of negative gravitactic orientation could be observed. The main maximum of sensitivity was detected 5 h after the beginning of the subjective day, the main minimum 5 h before the beginning of the subjective day. Transferring synchronized cultures to continuous light resulted in an almost instantaneous loss of rhythmicity. In contrast, after transfer to permanent darkness cells exhibited a circadian rhythm with a progressive shortening of the period for more than 5 days. These findings are in contrast to the circadian rhythm of phototaxis in Euglena, where a free-running period of 24 h was observed. Parallel measurements of negative gravitactic orientation, velocity, cell shape as well as cAMP concentration in synchronized cultures revealed a circadian rhythm of all reactions. The results are discussed with regard to the possible role of cell shape and cAMP in gravitactic orientation. PMID:11542916

  7. Human autonomic rhythms: vagal cardiac mechanisms in tetraplegic subjects

    NASA Technical Reports Server (NTRS)

    Koh, J.; Brown, T. E.; Beightol, L. A.; Ha, C. Y.; Eckberg, D. L.

    1994-01-01

    1. We studied eight young men (age range: 20-37 years) with chronic, clinically complete high cervical spinal cord injuries and ten age-matched healthy men to determine how interruption of connections between the central nervous system and spinal sympathetic motoneurones affects autonomic cardiovascular control. 2. Baseline diastolic pressures and R-R intervals (heart periods) were similar in the two groups. Slopes of R-R interval responses to brief neck pressure changes were significantly lower in tetraplegic than in healthy subjects, but slopes of R-R interval responses to steady-state arterial pressure reductions and increases were comparable. Plasma noradrenaline levels did not change significantly during steady-state arterial pressure reductions in tetraplegic patients, but rose sharply in healthy subjects. The range of arterial pressure and R-R interval responses to vasoactive drugs (nitroprusside and phenylephrine) was significantly greater in tetraplegic than healthy subjects. 3. Resting R-R interval spectral power at respiratory and low frequencies was similar in the two groups. During infusions of vasoactive drugs, low-frequency R-R interval spectral power was directly proportional to arterial pressure in tetraplegic patients, but was unrelated to arterial pressure in healthy subjects. Vagolytic doses of atropine nearly abolished both low- and respiratory-frequency R-R interval spectral power in both groups. 4. Our conclusions are as follows. First, since tetraplegic patients have significant levels of low-frequency arterial pressure and R-R interval spectral power, human Mayer arterial pressure waves may result from mechanisms that do not involve stimulation of spinal sympathetic motoneurones by brainstem neurones. Second, since in tetraplegic patients, low-frequency R-R interval spectral power is proportional to arterial pressure, it is likely to be mediated by a baroreflex mechanism. Third, since low-frequency R-R interval rhythms were nearly abolished

  8. A timely review of state-of-the-art chronopharmaceuticals synchronized with biological rhythms.

    PubMed

    Sewlall, Seshni; Pillay, Viness; Danckwerts, Michael P; Choonara, Yahya E; Ndesendo, Valence M K; du Toit, Lisa C

    2010-12-01

    Extensive research into circadian rhythms and their influence on biological systems has given rise to the science of chronobiology and subsequently chronotherapy, the science of delivering drugs in synchrony with biological rhythms. The field of chronotherapeutics paves the way for advances and complexities in current drug delivery technology. The ultimate goal of current chronopharmaceutical research strives to design ideal chronotherapeutic drug delivery systems that respond to such therapeutic needs. Considering the fact that physiological events such as heart rate, blood pressure, plasma concentration of hormones, plasma proteins and enzymes display constancy over time, drug delivery systems with constant release profiles have thus been favored. However, due to circadian rhythms, the conventional paradigm of constant drug delivery may not be what is needed. Instead, precisely timed drug delivery systems are required in order to correlate drug delivery with circadian rhythms to provide maximum therapeutic efficacy for chronotherapeutic diseases when most needed. The aim of this review paper is to outline the concepts in designing chronopharmaceuticals from a clinical viewpoint of major chronotherapeutic diseases such as asthma, allergic rhinitis, cardiovascular disorders, rheumatoid arthritis and cancer as well as relatively minor niche areas of interest such as in glaucoma, diabetes, immunity, pain, gastric ulcers, epilepsy and even HIV/AIDS that would require chronotherapy. In addition this review paper attempts to concisely assimilate and explicate the role of circadian rhythms in these various disease states and provide a focused overview of the current state-of-the-art in designing strategies for chronopharmaceutical formulations employed for treating chronotherapeutic diseases. PMID:20950265

  9. Wheel running improves REM sleep and attenuates stress-induced flattening of diurnal rhythms in F344 rats.

    PubMed

    Thompson, Robert S; Roller, Rachel; Greenwood, Benjamin N; Fleshner, Monika

    2016-05-01

    Regular physical activity produces resistance to the negative health consequences of stressor exposure. One way that exercise may confer stress resistance is by reducing the impact of stress on diurnal rhythms and sleep; disruptions of which contribute to stress-related disease including mood disorders. Given the link between diurnal rhythm disruptions and stress-related disorders and that exercise both promotes stress resistance and is a powerful non-photic biological entrainment cue, we tested if wheel running could reduce stress-induced disruptions of sleep/wake behavior and diurnal rhythms. Adult, male F344 rats with or without access to running wheels were instrumented for biotelemetric recording of diurnal rhythms of locomotor activity, heart rate, core body temperature (CBT), and sleep (i.e. REM, NREM, and WAKE) in the presence of a 12 h light/dark cycle. Following 6 weeks of sedentary or exercise conditions, rats were exposed to an acute stressor known to disrupt diurnal rhythms and produce behaviors associated with mood disorders. Prior to stressor exposure, exercise rats had higher CBT, more locomotor activity during the dark cycle, and greater %REM during the light cycle relative to sedentary rats. NREM and REM sleep were consolidated immediately following peak running to a greater extent in exercise, compared to sedentary rats. In response to stressor exposure, exercise rats expressed higher stress-induced hyperthermia than sedentary rats. Stressor exposure disrupted diurnal rhythms in sedentary rats; and wheel running reduced these effects. Improvements in sleep and reduced diurnal rhythm disruptions following stress could contribute to the health promoting and stress protective effects of exercise. PMID:27124542

  10. Cardiorespiratory Coupling: Common Rhythms in Cardiac, Sympathetic, and Respiratory Activities

    PubMed Central

    Dick, Thomas E.; Hsieh, Yee-Hsee; Dhingra, Rishi R.; Baekey, David M.; Galán, Roberto F.; Wehrwein, Erica; Morris, Kendall F.

    2014-01-01

    Cardiorespiratory coupling is an encompassing term describing more than the well-recognized influences of respiration on heart rate and blood pressure. Our data indicate that cardiorespiratory coupling reflects a reciprocal interaction between autonomic and respiratory control systems, and the cardiovascular system modulates the ventilatory pattern as well. For example, cardioventilatory coupling refers to the influence of heart beats and arterial pulse pressure on respiration and is the tendency for the next inspiration to start at a preferred latency after the last heart beat in expiration. Multiple complementary, well-described mechanisms mediate respiration’s influence on cardiovascular function, whereas mechanisms mediating the cardiovascular system’s influence on respiration may only be through the baroreceptors but are just being identified. Our review will describe a differential effect of conditioning rats with either chronic intermittent or sustained hypoxia on sympathetic nerve activity but also on ventilatory pattern variability. Both intermittent and sustained hypoxia increase sympathetic nerve activity after 2 weeks but affect sympatho-respiratory coupling differentially. Intermittent hypoxia enhances sympatho-respiratory coupling, which is associated with low variability in the ventilatory pattern. In contrast, after constant hypobaric hypoxia, 1-to-1 coupling between bursts of sympathetic and phrenic nerve activity is replaced by 2-to-3 coupling. This change in coupling pattern is associated with increased variability of the ventilatory pattern. After baro-denervating hypobaric hypoxic-conditioned rats, splanchnic sympathetic nerve activity becomes tonic (distinct bursts are absent) with decreases during phrenic nerve bursts and ventilatory pattern becomes regular. Thus, conditioning rats to either intermittent or sustained hypoxia accentuates the reciprocal nature of cardiorespiratory coupling. Finally, identifying a compelling physiologic

  11. From Biological Rhythms to Social Rhythms: Physiological Precursors of Mother-Infant Synchrony

    ERIC Educational Resources Information Center

    Feldman, Ruth

    2006-01-01

    Links between neonatal biological rhythms and the emergence of interaction rhythms were examined in 3 groups (N=71): high-risk preterms (HR; birth weight less than 1,000 g), low-risk preterms (LR; birth weight=1,700-1,850 g), and full-term (FT) infants. Once a week for premature infants and on the 2nd day for FT infants, sleep-wake cyclicity was…

  12. Influence of head-down bed rest on the circadian rhythms of hormones and electrolytes involved in hydroelectrolytic regulation

    NASA Technical Reports Server (NTRS)

    Millet, C.; Custaud, M. A.; Allevard, A. M.; Zaouali-Ajina, M.; Monk, T. H.; Arnaud, S. B.; Claustrat, B.; Gharib, C.; Gauquelin-Koch, G.

    2001-01-01

    We investigated in six men the impact of a 17-day head-down bed rest (HDBR) on the circadian rhythms of the hormones and electrolytes involved in hydroelectrolytic regulation. This HDBR study was designed to mimic an actual spaceflight. Urine samples were collected at each voiding before, during and after HDBR. Urinary excretion of aldosterone, arginine vasopressin (AVP), cyclic guanosine monophosphate (cGMP), cortisol, electrolytes (Na+ and K+) and creatinine were determined. HDBR resulted in a significant reduction of body mass (P < 0.01) and of caloric intake [mean (SEM) 2,778 (37) kcal.24 h(-1) to 2,450 (36) kcal.24 h(-1), where 1 kcal.h(-1) = 1.163 J.s(-1); P< 0.01]. There was a significant increase in diastolic blood pressure [71.8 (0.7) mmHg vs 75.6 (0.91) mmHg], with no significant changes in either systolic blood pressure or heart rate. The nocturnal hormonal decrease of aldosterone was clearly evident only before and after HDBR, but the day/night difference did not appear during HDBR. The rhythm of K+ excretion was unchanged during HDBR, whereas for Na+ excretion, a large decrease was shown during the night as compared to the day. The circadian rhythm of cortisol persisted. These data suggest that exposure to a 17-day HDBR could induce an exaggeration of the amplitude of the Na+ rhythm and abolition of the aldosterone rhythm.

  13. Characterisation of circadian rhythms of various duckweeds.

    PubMed

    Muranaka, T; Okada, M; Yomo, J; Kubota, S; Oyama, T

    2015-01-01

    The plant circadian clock controls various physiological phenomena that are important for adaptation to natural day-night cycles. Many components of the circadian clock have been identified in Arabidopsis thaliana, the model plant for molecular genetic studies. Recent studies revealed evolutionary conservation of clock components in green plants. Homologues of clock-related genes have been isolated from Lemna gibba and Lemna aequinoctialis, and it has been demonstrated that these homologues function in the clock system in a manner similar to their functioning in Arabidopsis. While clock components are widely conserved, circadian phenomena display diversity even within the Lemna genus. In order to survey the full extent of diversity in circadian rhythms among duckweed plants, we characterised the circadian rhythms of duckweed by employing a semi-transient bioluminescent reporter system. Using a particle bombardment method, circadian bioluminescent reporters were introduced into nine strains representing five duckweed species: Spirodela polyrhiza, Landoltia punctata, Lemna gibba, L. aequinoctialis and Wolffia columbiana. We then monitored luciferase (luc+) reporter activities driven by AtCCA1, ZmUBQ1 or CaMV35S promoters under entrainment and free-running conditions. Under entrainment, AtCCA1::luc+ showed similar diurnal rhythms in all strains. This suggests that the mechanism of biological timing under day-night cycles is conserved throughout the evolution of duckweeds. Under free-running conditions, we observed circadian rhythms of AtCCA1::luc+, ZmUBQ1::luc+ and CaMV35S::luc+. These circadian rhythms showed diversity in period length and sustainability, suggesting that circadian clock mechanisms are somewhat diversified among duckweeds. PMID:24942699

  14. Biologic rhythms derived from Siberian mammoths' hairs.

    PubMed

    Spilde, Mike; Lanzirotti, Antonio; Qualls, Clifford; Phillips, Genevieve; Ali, Abdul-Mehdi; Agenbroad, Larry; Appenzeller, Otto

    2011-01-01

    Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was ∼31 cms/year and ∼16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios), which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna. PMID:21747920

  15. Biologic Rhythms Derived from Siberian Mammoths' Hairs

    PubMed Central

    Spilde, Mike; Lanzirotti, Antonio; Qualls, Clifford; Phillips, Genevieve; Ali, Abdul-Mehdi; Agenbroad, Larry; Appenzeller, Otto

    2011-01-01

    Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was ∼31 cms/year and ∼16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios), which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna. PMID:21747920

  16. Biologic Rhythms Derived from Siberian Mammoths Hairs

    SciTech Connect

    M Spilde; A Lanzirotti; C Qualls; G Phillips; A Ali; L Agenbroad; O Appenzeller

    2011-12-31

    Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was {approx}31 cms/year and {approx}16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios), which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna.

  17. The Validity and Reliability of Rhythm Measurements in Automatically Scoring the English Rhythm Proficiency of Chinese EFL Learners

    ERIC Educational Resources Information Center

    Chen, Jin; Lin, Jianghao; Li, Xinguang

    2015-01-01

    This article aims to find out the validity of rhythm measurements to capture the rhythmic features of Chinese English. Besides, the reliability of the valid rhythm measurements applied in automatically scoring the English rhythm proficiency of Chinese EFL learners is also explored. Thus, two experiments were carried out. First, thirty students of…

  18. A prototype-based resonance model of rhythm categorization

    PubMed Central

    Bååth, Rasmus; Lagerstedt, Erik; Gärdenfors, Peter

    2014-01-01

    Categorization of rhythmic patterns is prevalent in musical practice, an example of this being the transcription of (possibly not strictly metrical) music into musical notation. In this article we implement a dynamical systems' model of rhythm categorization based on the resonance theory of rhythm perception developed by Large (2010). This model is used to simulate the categorical choices of participants in two experiments of Desain and Honing (2003). The model accurately replicates the experimental data. Our results support resonance theory as a viable model of rhythm perception and show that by viewing rhythm perception as a dynamical system it is possible to model central properties of rhythm categorization. PMID:26034564

  19. Modeling heart rate variability by stochastic feedback

    NASA Technical Reports Server (NTRS)

    Amaral, L. A.; Goldberger, A. L.; Stanley, H. E.

    1999-01-01

    We consider the question of how the cardiac rhythm spontaneously self-regulates and propose a new mechanism as a possible answer. We model the neuroautonomic regulation of the heart rate as a stochastic feedback system and find that the model successfully accounts for key characteristics of cardiac variability, including the 1/f power spectrum, the functional form and scaling of the distribution of variations of the interbeat intervals, and the correlations in the Fourier phases which indicate nonlinear dynamics.

  20. Rhythm measures and dimensions of durational variation in speech.

    PubMed

    Loukina, Anastassia; Kochanski, Greg; Rosner, Burton; Keane, Elinor; Shih, Chilin

    2011-05-01

    Patterns of durational variation were examined by applying 15 previously published rhythm measures to a large corpus of speech from five languages. In order to achieve consistent segmentation across all languages, an automatic speech recognition system was developed to divide the waveforms into consonantal and vocalic regions. The resulting duration measurements rest strictly on acoustic criteria. Machine classification showed that rhythm measures could separate languages at rates above chance. Within-language variability in rhythm measures, however, was large and comparable to that between languages. Therefore, different languages could not be identified reliably from single paragraphs. In experiments separating pairs of languages, a rhythm measure that was relatively successful at separating one pair often performed very poorly on another pair: there was no broadly successful rhythm measure. Separation of all five languages at once required a combination of three rhythm measures. Many triplets were about equally effective, but the confusion patterns between languages varied with the choice of rhythm measures. PMID:21568427

  1. [Interpersonal and social rhythm therapy (IPSRT)].

    PubMed

    Bottai, T; Biloa-Tang, M; Christophe, S; Dupuy, C; Jacquesy, L; Kochman, F; Meynard, J-A; Papeta, D; Rahioui, H; Adida, M; Fakra, E; Kaladjian, A; Pringuey, D; Azorin, J-M

    2010-12-01

    Bipolar disorder is common, recurrent, often severe and debiliting disorder. All types of bipolar disorder have a common determinant: depressive episode. It is justify to propose a psychotherapy which shown efficacy in depression. Howewer, perturbations in circadian rhythms have been implicated in the genesis of each episode of the illness. Biological circadian dysregulation can be encouraged by alteration of time-givers (Zeitgebers) or occurrence of time-disturbers (Zeitstörers). Addition of social rhythm therapy to interpersonal psychotherapy leads to create a new psychotherapy adaptated to bipolar disorders: InterPersonal and Social Rhythm Therapy (IPSRT). IPSRT, in combinaison with medication, has demonstrated efficacy as a treatment for bipolar disorders. IPSRT combines psychoeducation, behavioral strategy to regularize daily routines and interpersonal psychotherapy which help patients cope better with the multiple psychosocial and relationship problems associated with this chronic disorder. The main issues of this psychotherapy are: to take the history of the patient's illness and review of medication, to help patient for "grief for the lost healthy self" translated in the french version in "acceptance of a long-term medical condition", to give the sick role, to examinate the current relationships and changes proximal to the emergence of mood symptoms in the four problem areas (unresolved grief, interpersonal disputes, role transitions, role déficits), to examinate and increase daily routines and social rhythms. French version of IPSRT called TIPARS (with few differences), a time-limited psychotherapy, in 24 sessions during approximatively 6 months, is conducted in three phases. In the initial phase, the therapist takes a thorough history of previous episodes and their interpersonal context and a review of previous medication, provides psychoeducation, evaluates social rhythms, introduces the Social Rhythm Metric, identifies the patient's main interpersonal

  2. Impairment of beat-based rhythm discrimination in Parkinson's disease.

    PubMed

    Grahn, Jessica A; Brett, Matthew

    2009-01-01

    Humans often synchronize movements to the beat, indicating that motor areas may be involved in detecting or generating a beat. The basal ganglia have been shown to be preferentially activated by perception of rhythms with a regular beat (Grahn and Brett, 2007), but their necessity for beat-based rhythm processing has not been proven. Previous research has shown that Parkinson's disease (PD) patients are impaired in timing of isochronous intervals (Harrington et al., 1998a; O'Boyle et al., 1996), but little work has tested more complex rhythms. In healthy volunteers, behavioural performance is better for rhythms with a beat than without a beat (Essens, 1986). We tested PD patients and controls on a rhythm discrimination task to determine if basal ganglia dysfunction results in an impairment of processing rhythms that have a beat. Unlike rhythm reproduction, discrimination has no motor requirements that are problematic for patients. Half the rhythms had a beat-based structure, and half did not. Subjects heard a rhythm twice and then indicated if a third presentation of the rhythm was the same or different. We predicted that PD patients would benefit less from beat structure than controls, resulting in a group by rhythm-type interaction, with reduced relative performance for the beat-based sequences in the PD group. Indeed this was the pattern of the results. In the control group, a significant advantage was observed for discrimination of rhythms with a beat compared to those without a beat. This advantage was greatly reduced in the PD group. Discrimination of beat-based rhythms was significantly impaired in PD patients compared to controls, whereas discrimination of non-beat-based rhythms did not differ significantly. This suggests that the basal ganglia are part of a system involved in detecting or generating an internal beat, and that this system is compromised in patients with Parkinson's disease. PMID:19027895

  3. Successful orthotopic heart transplantation using a donor heart with ALCAPA.

    PubMed

    Simmonds, J D; Mustafa, M; Fajardo Jaramillo, D P; Bellsham-Revell, H R; Marek, J; Burch, M; Tsang, V T; Muthialu, N

    2016-09-01

    With the imbalance between donation rates and potential recipients growing, transplant programs are increasingly using non-ideal organs from so-called marginal donors. This is the first reported case of the intentional use of a donor heart with ALCAPA. The recipient was aged one yr with restrictive cardiomyopathy who had been supported with BiVAD for over six months. Function of the donor left ventricle was shown to be well preserved, with no obvious signs of ischemia, except for a fibrotic layer on the anterolateral papillary muscle of the mitral valve. To prevent coronary steal, the anomalous left coronary artery ostium from the MPA was oversewn prior to implantation. The transplanted heart spontaneously regained sinus rhythm immediately following cross-clamp release and showed good contractility from the first postoperative echocardiogram. The patient continues to do well 18 months post-transplant, with excellent function on echocardiography, and good flow on coronary angiography. PMID:27384867

  4. Heart pacemaker

    MedlinePlus

    ... 1 ounce. Most pacemakers have 2 parts: The generator contains the battery and the information to control ... are wires that connect the heart to the generator and carry the electrical messages to the heart. ...

  5. Heart Health

    MedlinePlus

    ... nih.gov/Go4Life Heart Health Just like an engine makes a car go, your heart keeps your ... all at once —10-minute periods will do. Start by doing activities you enjoy—brisk walking, dancing, ...

  6. Heart Disease

    MedlinePlus

    ... with heart disease? What do my cholesterol and triglyceride numbers mean? How can I lower my cholesterol? ... weight Know your numbers (blood pressure, cholesterol, and triglycerides) You can reduce your chances of getting heart ...

  7. Heart Failure

    MedlinePlus

    ... arrhythmias) The use of toxic substances (such as alcohol or drug abuse) Congenital heart defect (a heart problem you were born with) Diabetes Thyroid problems Diagnosis & Tests How will my doctor know if I ...

  8. Heart Disease

    MedlinePlus

    ... this? Submit What's this? Submit Button Related CDC Web Sites Division for Heart Disease and Stroke Prevention ... this? Submit What's this? Submit Button Related CDC Web Sites Division for Heart Disease and Stroke Prevention ...

  9. Healthy Lifestyle Interventions to Combat Noncommunicable Disease—A Novel Nonhierarchical Connectivity Model for Key Stakeholders: A Policy Statement From the American Heart Association, European Society of Cardiology, European Association for Cardiovascular Prevention and Rehabilitation, and American College of Preventive Medicine.

    PubMed

    Arena, Ross; Guazzi, Marco; Lianov, Liana; Whitsel, Laurie; Berra, Kathy; Lavie, Carl J; Kaminsky, Leonard; Williams, Mark; Hivert, Marie-France; Franklin, Nina Cherie; Myers, Jonathan; Dengel, Donald; Lloyd-Jones, Donald M; Pinto, Fausto J; Cosentino, Francesco; Halle, Martin; Gielen, Stephan; Dendale, Paul; Niebauer, Josef; Pelliccia, Antonio; Giannuzzi, Pantaleo; Corra, Ugo; Piepoli, Massimo F; Guthrie, George; Shurney, Dexter

    2015-08-01

    Noncommunicable diseases (NCDs) have become the primary health concern for most countries around the world. Currently, more than 36 million people worldwide die from NCDs each year, accounting for 63% of annual global deaths; most are preventable. The global financial burden of NCDs is staggering, with an estimated 2010 global cost of $6.3 trillion (US dollars) that is projected to increase to $13 trillion by 2030. A number of NCDs share one or more common predisposing risk factors, all related to lifestyle to some degree: (1) cigarette smoking, (2) hypertension, (3) hyperglycemia, (4) dyslipidemia, (5) obesity, (6) physical inactivity, and (7) poor nutrition. In large part, prevention, control, or even reversal of the aforementioned modifiable risk factors are realized through leading a healthy lifestyle (HL). The challenge is how to initiate the global change, not toward increasing documentation of the scope of the problem but toward true action-creating, implementing, and sustaining HL initiatives that will result in positive, measurable changes in the previously defined poor health metrics. To achieve this task, a paradigm shift in how we approach NCD prevention and treatment is required. The goal of this American Heart Association/European Society of Cardiology/European Association for Cardiovascular Prevention and Rehabilitation/American College of Preventive Medicine policy statement is to define key stakeholders and highlight their connectivity with respect to HL initiatives. This policy encourages integrated action by all stakeholders to create the needed paradigm shift and achieve broad adoption of HL behaviors on a global scale. PMID:26143646

  10. Heart Attack

    MedlinePlus

    ... a million people in the U.S. have a heart attack. About half of them die. Many people have permanent heart damage or die because they don't get ... It's important to know the symptoms of a heart attack and call 9-1-1 if someone ...

  11. Sleep, Circadian Rhythms, and Anxious Traits.

    PubMed

    Coles, Meredith E; Schubert, Jessica R; Nota, Jacob A

    2015-09-01

    Anxiety is adaptive and plays an important role in keeping us safe. However, when anxiety becomes too extreme, it can cause significant disruptions and distress. Understanding the mechanisms underlying excessive anxiety and how to best treat it is a priority for researchers and clinicians. There is increasing recognition that disruptions in the amount and timing of sleep are associated with anxiety symptoms and characteristics. In the current paper, we explore the intersections between sleep, circadian rhythms, and anxiety. First, we review accumulating evidence that anxiety is associated with disruptions in sleep and circadian rhythms in both clinical and nonclinical samples and across ages. Next, we discuss the data linking sleep disruptions with anxiety-related traits (anxiety sensitivity, neuroticism, and perfectionism) and patterns of cognition and emotion. Finally, potential treatment implications are highlighted. Overall, these data suggest that delineating the role of disruptions in the amount and timing of sleep holds promise for improving the lives of individuals with heightened anxiety. PMID:26216591

  12. Circadian rhythms: basic neurobiology and clinical applications.

    PubMed

    Moore, R Y

    1997-01-01

    Circadian rhythms are major features of adaptation to our environment. In mammals, circadian rhythms are generated and regulated by a circadian timing system. This system consists of entertainment pathways, pacemakers, and pace-maker output to effector systems that are under circadian control. The primary entertainment pathway is the retinohypothalamic tract, which terminates in the circadian pacemakers, the suprachiasmatic nuclei of the hypothalamus. The output of the suprachiasmatic nuclei is principally to the hypothalamus, the midline thalamus, and the basal forebrain. This provides a temporal organization to the sleep-wake cycle, to many physiological and endocrine functions, and to psychomotor performance functions. Disorders of circadian timing primarily affect entertainment and pacemaker functions. The pineal hormone, melatonin, appears to be promising agent for therapy of some circadian timing disorders. PMID:9046960

  13. [Molecular oscillatory machinery of circadian rhythms].

    PubMed

    Yamaguchi, Yoshiaki; Okamura, Hitoshi

    2012-07-01

    Many metabolic and physiological processes display daily rhythms oscillated by the internal circadian clock system. This rhythm is generated by interlocked transcription-(post) translation feedback loops of clock genes: the core oscillatory loop, being composed of CLOCK/BMAL1 heterodimer activating the expressions of PER and CRY that directly repress CLOCK/BMAL1, is accompanied by accessory loops consisted with REV-ERB nuclear receptor repressing Bmal1 or with DBP competing with E4BP4 on D-box site. These clock proteins are regulated by phosphorylation and ubiquitination (PER/CRY), and acetylation (CLOCK/BMAL1). Recently, a deacetylating protein SIRT1 mediated metabolic pathway is discovered to be interlocked with core oscillatory loop via Nampt expression, a late-limiting enzyme in NAD+ salvage pathway. Since many key-step enzymes of metabolisms are regulated by the circadian clock, circadian clock system may intimately link to cellular metabolism. PMID:22844791

  14. Circadian rhythms of performance: new trends

    NASA Technical Reports Server (NTRS)

    Carrier, J.; Monk, T. H.

    2000-01-01

    This brief review is concerned with how human performance efficiency changes as a function of time of day. It presents an overview of some of the research paradigms and conceptual models that have been used to investigate circadian performance rhythms. The influence of homeostatic and circadian processes on performance regulation is discussed. The review also briefly presents recent mathematical models of alertness that have been used to predict cognitive performance. Related topics such as interindividual differences and the postlunch dip are presented.

  15. Circadian rhythms of women with fibromyalgia

    NASA Technical Reports Server (NTRS)

    Klerman, E. B.; Goldenberg, D. L.; Brown, E. N.; Maliszewski, A. M.; Adler, G. K.

    2001-01-01

    Fibromyalgia syndrome is a chronic and debilitating disorder characterized by widespread nonarticular musculoskeletal pain whose etiology is unknown. Many of the symptoms of this syndrome, including difficulty sleeping, fatigue, malaise, myalgias, gastrointestinal complaints, and decreased cognitive function, are similar to those observed in individuals whose circadian pacemaker is abnormally aligned with their sleep-wake schedule or with local environmental time. Abnormalities in melatonin and cortisol, two hormones whose secretion is strongly influenced by the circadian pacemaker, have been reported in women with fibromyalgia. We studied the circadian rhythms of 10 women with fibromyalgia and 12 control healthy women. The protocol controlled factors known to affect markers of the circadian system, including light levels, posture, sleep-wake state, meals, and activity. The timing of the events in the protocol were calculated relative to the habitual sleep-wake schedule of each individual subject. Under these conditions, we found no significant difference between the women with fibromyalgia and control women in the circadian amplitude or phase of rhythms of melatonin, cortisol, and core body temperature. The average circadian phases expressed in hours posthabitual bedtime for women with and without fibromyalgia were 3:43 +/- 0:19 and 3:46 +/- 0:13, respectively, for melatonin; 10:13 +/- 0:23 and 10:32 +/- 0:20, respectively for cortisol; and 5:19 +/- 0:19 and 4:57 +/- 0:33, respectively, for core body temperature phases. Both groups of women had similar circadian rhythms in self-reported alertness. Although pain and stiffness were significantly increased in women with fibromyalgia compared with healthy women, there were no circadian rhythms in either parameter. We suggest that abnormalities in circadian rhythmicity are not a primary cause of fibromyalgia or its symptoms.

  16. Subjective alertness rhythms in elderly people

    NASA Technical Reports Server (NTRS)

    Monk, T. H.; Buysse, D. J.; Reynolds, C. F. 3rd; Kupfer, D. J.; Houck, P. R.

    1996-01-01

    The aim of this study was to evaluate age-related changes in the circadian rhythm of subjective alertness and to explore the circadian mechanisms underlying such changes. Using a visual analogue scale (VAS) instrument, 25 older men and women (71 y and older; 15 female, 10 male) rated their subjective alertness about 7 times per day during 5 baseline days of temporal isolation during which habitual bedtimes and waketimes were enforced. Comparisons were made with 13 middle-aged men (37-52 y) experiencing the same protocol. Advancing age (particularly in the men) resulted in less rhythmic alertness patterns, as indicated by lower amplitudes and less reliability of fitted 24-h sinusoids. This appeared in spite of the absence of any reliable age-related diminution in circadian temperature rhythm amplitude, thus suggesting the effect was not due to SCN weakness per se, but to weakened transduction of SCN output. In a further experiment, involving 36 h of constant wakeful bedrest, differences in the amplitude of the alertness rhythm were observed between 9 older men (79 y+), 7 older women (79 y+), and 17 young controls (9 males, 8 females, 19-28 y) suggesting that with advancing age (particularly in men) there is less rhythmic input into subjective alertness from the endogenous circadian pacemaker. These results may explain some of the nocturnal insomnia and daytime hypersomnia that afflict many elderly people.

  17. Respiratory modulation of human autonomic rhythms

    NASA Technical Reports Server (NTRS)

    Badra, L. J.; Cooke, W. H.; Hoag, J. B.; Crossman, A. A.; Kuusela, T. A.; Tahvanainen, K. U.; Eckberg, D. L.

    2001-01-01

    We studied the influence of three types of breathing [spontaneous, frequency controlled (0.25 Hz), and hyperventilation with 100% oxygen] and apnea on R-R interval, photoplethysmographic arterial pressure, and muscle sympathetic rhythms in nine healthy young adults. We integrated fast Fourier transform power spectra over low (0.05-0.15 Hz) and respiratory (0.15-0.3 Hz) frequencies; estimated vagal baroreceptor-cardiac reflex gain at low frequencies with cross-spectral techniques; and used partial coherence analysis to remove the influence of breathing from the R-R interval, systolic pressure, and muscle sympathetic nerve spectra. Coherence among signals varied as functions of both frequency and time. Partialization abolished the coherence among these signals at respiratory but not at low frequencies. The mode of breathing did not influence low-frequency oscillations, and they persisted during apnea. Our study documents the independence of low-frequency rhythms from respiratory activity and suggests that the close correlations that may exist among arterial pressures, R-R intervals, and muscle sympathetic nerve activity at respiratory frequencies result from the influence of respiration on these measures rather than from arterial baroreflex physiology. Most importantly, our results indicate that correlations among autonomic and hemodynamic rhythms vary over time and frequency, and, thus, are facultative rather than fixed.

  18. Detecting Rhythms in Time Series with RAIN

    PubMed Central

    Thaben, Paul F.; Westermark, Pål O.

    2014-01-01

    A fundamental problem in research on biological rhythms is that of detecting and assessing the significance of rhythms in large sets of data. Classic methods based on Fourier theory are often hampered by the complex and unpredictable characteristics of experimental and biological noise. Robust nonparametric methods are available but are limited to specific wave forms. We present RAIN, a robust nonparametric method for the detection of rhythms of prespecified periods in biological data that can detect arbitrary wave forms. When applied to measurements of the circadian transcriptome and proteome of mouse liver, the sets of transcripts and proteins with rhythmic abundances were significantly expanded due to the increased detection power, when we controlled for false discovery. Validation against independent data confirmed the quality of these results. The large expansion of the circadian mouse liver transcriptomes and proteomes reflected the prevalence of nonsymmetric wave forms and led to new conclusions about function. RAIN was implemented as a freely available software package for R/Bioconductor and is presently also available as a web interface. PMID:25326247

  19. Chronotypes and rhythm stability in mice.

    PubMed

    Wicht, Helmut; Korf, Horst-Werner; Ackermann, Hanns; Ekhart, Daniel; Fischer, Claudia; Pfeffer, Martina

    2014-02-01

    Humans come in different chronotypes: The phase of their sleep-wake cycle with respect to the phase of the external, sidereal cycle of night and day differs. Colloquially, the early chronotypes are addressed as "larks," the late ones as "owls." The human chronotype can be quantified in hours and minutes of local time by determining the median of the sleep phase. Demographically, early and late human chronotypes differ with respect to the stability of their rhythms and the prevalence of several widespread diseases and risk factors, such as depression, nicotine abuse, and others. Inbred mice are widely used in chronobiological research as model organisms, but up to now there was no way to chronotype them. We have developed a method to chronotype mice in hours and fractions of hours by measuring the median of activity (MoA) and have shown that different mouse strains have significantly different MoAs and, thus, chronotypes. We have further developed methods to estimate the stability of the behavioral rhythms and found that "late" mice have relatively instable rhythms. Our methods permit the use of inbred mice for investigations into the molecular and genetic background of the chronotype and the prevalence of risks and diseases that are associated with it. PMID:24079808

  20. Differential short-term memorisation for vocal and instrumental rhythms.

    PubMed

    Klyn, Niall A M; Will, Udo; Cheong, Yong-Jeon; Allen, Erin T

    2016-07-01

    This study explores differential processing of vocal and instrumental rhythms in short-term memory with three decision (same/different judgments) and one reproduction experiment. In the first experiment, memory performance declined for delayed versus immediate recall, with accuracy for the two rhythms being affected differently: Musicians performed better than non-musicians on clapstick but not on vocal rhythms, and musicians were better on vocal rhythms in the same than in the different condition. Results for the second experiment showed that concurrent sub-vocal articulation and finger-tapping differentially affected the two rhythms and same/different decisions, but produced no evidence for articulatory loop involvement in delayed decision tasks. In a third experiment, which tested rhythm reproduction, concurrent sub-vocal articulation decreased memory performance, with a stronger deleterious effect on the reproduction of vocal than of clapstick rhythms. This suggests that the articulatory loop may only be involved in delayed reproduction not in decision tasks. The fourth experiment tested whether differences between filled and empty rhythms (continuous vs. discontinuous sounds) can explain the different memorisation of vocal and clapstick rhythms. Though significant differences were found for empty and filled instrumental rhythms, the differences between vocal and clapstick can only be explained by considering additional voice specific features. PMID:26274938

  1. Sex and race differences in the prevalence of Fatty Liver Disease as measured by CT liver attenuation in European American and African American participants of the NHLBI Family Heart Study

    PubMed Central

    North, K.E.; Graff, M; Franceschini, N.; Reiner, A.P.; Feitosa, M.F.; Carr, J.J.; Gordon-Larsen, P.; Wojczynski, M. K.; Borecki, I.B.

    2011-01-01

    Liver attenuation (LA) (Hounsfield Units, HU) by computed tomography (CT) is a validated quantitative measure inversely related to liver fat burden. We examined race-and sex- differences on the distribution of LA (one of the first stages of fatty liver disease) and the predictors of these mean differences in European American (EA) and African American (AA) participants of the Family Heart Study. A total of 1242 (1064 EA, 178 AA) and 1477 (1150 EA, 327 AA) men and women, respectively, underwent CT examination from which LA and abdominal adipose volume were measured. LA (adjusted for phantom and field center) was the dependent variable in linear mixed models (to control for family relatedness) that tested for mean differences by race and by sex. Independent explanatory variables included age, body mass index, visceral adipose tissue volume, subcutaneous adipose tissue volume, alcohol consumption, TG, HDL-C, and insulin resistance. Mean LA varied significantly by sex, [(men) 57.76 ±10.03 HU and (women) 60.03 ±10.91 HU, p=0.0002], but not by race. Higher LA was associated with older age, while higher values of VAT, triglycerides, and insulin resistance were associated with lower LA in men and women. In contrast, alcohol consumption and BMI were associated with lower LA only among men. In analyses stratified by race LA was associated with alcohol consumption, VAT, and insulin resistance in both EA and AA and with age, BMI, and HDL-C in EA participants only. Our study findings confirm that there are important sex differences and race by sex interaction effects on the distribution of liver attenuation, the prevalence of FLD, and on the influence of metabolic risk factors on LA and FLD. PMID:21900826

  2. Noise-induced synchronous stochastic oscillations in small scale cultured heart-cell networks

    NASA Astrophysics Data System (ADS)

    Yuan, Lan; Liu, Zhi-Qiang; Zhang, Hui-Min; Ding, Xue-Li; Yang, Ming-Hao; Gu, Hua-Guang; Ren, Wei

    2011-02-01

    This paper reports that the synchronous integer multiple oscillations of heart-cell networks or clusters are observed in the biology experiment. The behaviour of the integer multiple rhythm is a transition between super- and subthreshold oscillations, the stochastic mechanism of the transition is identified. The similar synchronized oscillations are theoretically reproduced in the stochastic network composed of heterogeneous cells whose behaviours are chosen as excitable or oscillatory states near a Hopf bifurcation point. The parameter regions of coupling strength and noise density that the complex oscillatory rhythms can be simulated are identified. The results show that the rhythm results from a simple stochastic alternating process between super- and sub-threshold oscillations. Studies on single heart cells forming these clusters reveal excitable or oscillatory state nearby a Hopf bifurcation point underpinning the stochastic alternation. In discussion, the results are related to some abnormal heartbeat rhythms such as the sinus arrest.

  3. Towards Active Tracking of Beating Heart Motion in the Presence of Arrhythmia for Robotic Assisted Beating Heart Surgery

    PubMed Central

    Tuna, E. Erdem; Karimov, Jamshid H.; Liu, Taoming; Bebek, Özkan; Fukamachi, Kiyotaka; Çavuşoğlu, M. Cenk

    2014-01-01

    In robotic assisted beating heart surgery, the control architecture for heart motion tracking has stringent requirements in terms of bandwidth of the motion that needs to be tracked. In order to achieve sufficient tracking accuracy, feed-forward control algorithms, which rely on estimations of upcoming heart motion, have been proposed in the literature. However, performance of these feed-forward motion control algorithms under heart rhythm variations is an important concern. In their past work, the authors have demonstrated the effectiveness of a receding horizon model predictive control-based algorithm, which used generalized adaptive predictors, under constant and slowly varying heart rate conditions. This paper extends these studies to the case when the heart motion statistics change abruptly and significantly, such as during arrhythmias. A feasibility study is carried out to assess the motion tracking capabilities of the adaptive algorithms in the occurrence of arrhythmia during beating heart surgery. Specifically, the tracking performance of the algorithms is evaluated on prerecorded motion data, which is collected in vivo and includes heart rhythm irregularities. The algorithms are tested using both simulations and bench experiments on a three degree-of-freedom robotic test bed. They are also compared with a position-plus-derivative controller as well as a receding horizon model predictive controller that employs an extended Kalman filter algorithm for predicting future heart motion. PMID:25048462

  4. Mean platelet volume is related with ischemic stroke in patients with sinus rhythm.

    PubMed

    Özkan, Buğra; Arik, Osman Z; Gözükara, Mehmet Y; Şahin, Durmuş Y; Topal, Salih; Uysal, Onur K; Elbasan, Zafer; Epçeliden, Tuncay; Çayli, Murat; Gür, Mustafa

    2016-07-01

    Stroke is the leading cause of disability worldwide. It is known that atrial fibrillation and left atrial enlargement contribute ischemic stroke, and mean platelet volume (MPV) increases in patients with ischemic stroke and atrial fibrillation. We aimed to determine whether higher MPV is associated with ischemic stroke in patients with sinus rhythm. We evaluated 74 patients in sinus rhythm and with ischemic stroke (Group 1) and 90 age-matched and sex-matched healthy individuals as control group (Group 2). After physical and echocardiographic examination, 24-48 h Holter monitoring and complete blood counts were studied. There were no statistically significant differences in age, sex rates, and comorbidities between groups. Left atrial diameter was higher in Group 1 than Group 2 (P = 0.001), but both were in normal range. MPV was significantly higher in Group 1 (P < 0.001) and was an independent determinant [odds ratio (OR): 1.840; P < 0.001; 95% confidence interval (CI) 1.330-2.545] of ischemic stroke with left atrial (OR: 1.138; P = 0.006; 95% CI 1.037-1.248). In conclusion, higher MPV is associated with acute ischemic stroke in patients with sinus rhythm and without heart failure or left atrial enlargement. MPV and left atrial diameter are independent predictors of ischemic stroke in this patient population. PMID:24686100

  5. Arm and wrist surface potential mapping for wearable ECG rhythm recording devices: a pilot clinical study

    NASA Astrophysics Data System (ADS)

    Lynn, W. D.; Escalona, O. J.; McEneaney, D. J.

    2013-06-01

    This study addresses an important question in the development of a ECG device that enables long term monitoring of cardiac rhythm. This device would utilise edge sensor technologies for dry, non-irritant skin contact suitable for distal limb application and would be supported by embedded ECG denoising processes. Contemporary ECG databases including those provided by MIT-BIH and Physionet are focused on interpretation of cardiac disease and rhythm tracking. The data is recorded using chest leads as in standard clinical practise. For the development of a peripherally located heart rhythm monitor, such data would be of limited use. To provide a useful database adequate for the development of the above mentioned cardiac monitoring device a unipolar body surface potential map from the left arm and wrist was gathered in 37 volunteer patients and characterized in this study. For this, the reference electrode was placed at the wrist. Bipolar far-field electrogram leads were derived and analysed. Factors such as skin variability, 50Hz noise interference, electrode contact noise, motion artifacts and electromyographic noise, presented a challenge. The objective was quantify the signal-to-noise ratio (SNR) at the far-field locations. Preliminary results reveal that an electrogram indicative of the QRS complex can be recorded on the distal portion of the left arm when denoised using signal averaging techniques.

  6. Feedback control of human alpha rhythm from the central area.

    PubMed

    Potolicchio, S J; Zukerman, A S; Chernigovskaya, N V

    1979-09-01

    Twenty subjects, aged 17 to 25, were given from 5 to 10 sessions of training in controlling alpha. They were divided into three groups, respectively reinforced for increasing alpha from the central area, reinforced for decreasing alpha from the central area, and given noncontingent reinforcement. Compared with the initial baseline, the alpha of the noncontingent subjects did not change, while those reinforced for increases were reliably higher and those reinforced for decreases reliably lower than the noncontingent group. A slight trend toward improvement during successive sessions was not reliable. Since the experiment was conducted in the Soviet Union, the subjects had no expectations of an "alpha experience." Although tests showed a slight elevation in mood at the end of the sessions, there were no differences among the groups. There was an increase in reports of fatigue after the training sessions. There were no reports of using visual or somatomotor maneuvers as a means of controlling alpha. Furthermore, alpha rhythm control was not found to be consistently correlated with changes in heart rate, respiration, or mood, as determined by cross-correlation analysis. PMID:486587

  7. Circadian rhythms and fractal fluctuations in forearm motion

    NASA Astrophysics Data System (ADS)

    Hu, Kun; Hilton, Michael F.

    2005-03-01

    Recent studies have shown that the circadian pacemaker --- an internal body clock located in the brain which is normally synchronized with the sleep/wake behavioral cycles --- influences key physiologic functions such as the body temperature, hormone secretion and heart rate. Surprisingly, no previous studies have investigated whether the circadian pacemaker impacts human motor activity --- a fundamental physiologic function. We investigate high-frequency actigraph recordings of forearm motion from a group of young and healthy subjects during a forced desynchrony protocol which allows to decouple the sleep/wake cycles from the endogenous circadian cycle while controlling scheduled behaviors. We investigate both static properties (mean value, standard deviation), dynamical characteristics (long-range correlations), and nonlinear features (magnitude and Fourier-phase correlations) in the fluctuations of forearm acceleration across different circadian phases. We demonstrate that while the static properties exhibit significant circadian rhythms with a broad peak in the afternoon, the dynamical and nonlinear characteristics remain invariant with circadian phase. This finding suggests an intrinsic multi-scale dynamic regulation of forearm motion the mechanism of which is not influenced by the circadian pacemaker, thus suggesting that increased cardiac risk in the early morning hours is not related to circadian-mediated influences on motor activity.

  8. [Central EEG rhythm associated with movement and EEG rhythm associated with spatial reasoning: are they homologous?].

    PubMed

    Tarotin, I V; Ivanitsky, G A

    2014-01-01

    EEG rhythmical picture of subject's movement suppression and spatial-figurative task solving was examined and analyzed. Rhythms appearing during spatial reasoning and suppressed movements with the frequency of about 11 Hz were isolated. It was hypothesized that a functional link exists between these rhythms in the considered behavioral tests. To test the hypothesis and to reveal this connection, experiments were developed and carried out. Then the analysis of recorded EEG signals was conducted by applying Fourier transform, independent component analysis (ICA) and equivalent dipole source localization. Unexpected conclusion about the existence of a general mechanism of movement suppression was drawn. PMID:25975138

  9. Conventional rhythms enhance infants' and adults' perception of musical patterns.

    PubMed

    Trehub, Sandra E; Hannon, Erin E

    2009-01-01

    Listeners may favour particular rhythms because of their degree of conformity to culture-specific expectations or because of perceptual constraints that are apparent early in development. In two experiments we examined adults' and 6-month-old infants' detection of subtle rhythmic and melodic changes to two sequences of tones, a conventional rhythm that musically untrained adults rated as rhythmically good and an unconventional rhythm that was rated as poor. Detection of the changes was above chance in all conditions, but adults and infants performed more accurately in the context of the conventional rhythm. Unlike adults, who benefited from rhythmic conventionality only when detecting rhythmic changes, infants benefited when detecting melodic as well as rhythmic changes. The findings point to infant and adult parallels for some aspects of rhythm processing and to integrated perception of rhythm and melody early in life. PMID:19058799

  10. Experiment K-7-35: Circadian Rhythms and Temperature Regulation During Spaceflight. Part 1; Circadian Rhythms and Temperature Regulation

    NASA Technical Reports Server (NTRS)

    Fuller, C. A.; Alpatov, A. M.; Hoban-Higgins, T. M.; Klimovitsky, V. Y.

    1994-01-01

    Mammals have developed the ability to adapt to most variations encountered in their everyday environment. For example, homeotherms have developed the ability to maintain the internal cellular environment at a relatively constant temperature. Also, in order to compensate for temporal variations in the terrestrial environment, the circadian timing system has evolved. However, throughout the evolution of life on earth, living organisms have been exposed to the influence of an unvarying level of earth's gravity. As a result changes in gravity produce adaptive responses which are not completely understood. In particular, spaceflight has pronounced effects on various physiological and behavioral systems. Such systems include body temperature regulation and circadian rhythms. This program has examined the influence of microgravity on temperature regulation and circadian timekeeping systems in Rhesus monkeys. Animals flown on the Soviet Biosatellite, COSMOS 2044, were exposed to 14 days of microgravity while constantly monitoring the circadian patterns temperature regulation, heart rate and activity. This experiment has extended our previous observations from COSMOS 1514, as well as providing insights into the physiological mechanisms that produce these changes.

  11. Chronic phase advance alters circadian physiological rhythms and peripheral molecular clocks.

    PubMed

    Wolff, Gretchen; Duncan, Marilyn J; Esser, Karyn A

    2013-08-01

    Shifting the onset of light, acutely or chronically, can profoundly affect responses to infection, tumor progression, development of metabolic disease, and mortality in mammals. To date, the majority of phase-shifting studies have focused on acute exposure to a shift in the timing of the light cycle, whereas the consequences of chronic phase shifts alone on molecular rhythms in peripheral tissues such as skeletal muscle have not been studied. In this study, we tested the effect of chronic phase advance on the molecular clock mechanism in two phenotypically different skeletal muscles. The phase advance protocol (CPA) involved 6-h phase advances (earlier light onset) every 4 days for 8 wk. Analysis of the molecular clock, via bioluminescence recording, in the soleus and flexor digitorum brevis (FDB) muscles and lung demonstrated that CPA advanced the phase of the rhythm when studied immediately after CPA. However, if the mice were placed into free-running conditions (DD) for 2 wk after CPA, the molecular clock was not phase shifted in the two muscles but was still shifted in the lung. Wheel running behavior remained rhythmic in CPA mice; however, the endogenous period length of the free-running rhythm was significantly shorter than that of control mice. Core body temperature, cage activity, and heart rate remained rhythmic throughout the experiment, although the onset of the rhythms was significantly delayed with CPA. These results provide clues that lifestyles associated with chronic environmental desynchrony, such as shift work, can have disruptive effects on the molecular clock mechanism in peripheral tissues, including both types of skeletal muscle. Whether this can contribute, long term, to increased incidence of insulin resistance/metabolic disease requires further study. PMID:23703115

  12. Aged rats show dominant modulation of lower frequency hippocampal theta rhythm during running.

    PubMed

    Li, Jia-Yi; Kuo, Terry B J; Yang, Cheryl C H

    2016-10-01

    Aging causes considerable decline in both physiological and mental functions, particularly cognitive function. The hippocampal theta rhythm (4-12Hz) is related to both cognition and locomotion. Aging-related findings of the frequency and amplitude of hippocampal theta oscillations are inconsistent and occasionally contradictory. This inconsistency may be due to the effects of the sleep/wake state and different frequency subbands being overlooked. We assumed that aged rats have lower responses of the hippocampal theta rhythm during running, which is mainly due to the dominant modulation of theta frequency subbands related to cognition. By simultaneously recording electroencephalography, physical activity (PA), and the heart rate (HR), this experiment explored the theta oscillations before, during, and after treadmill running at a constant speed in 8-week-old (adult) and 60-week-old (middle-aged) rats. Compared with adult rats, the middle-aged rats exhibited lower theta activity in all frequency ranges before running. Running increased the theta frequency (Frq, 4-12Hz), total activity of the whole theta band (total power, TP), activity of the middle theta frequency (MT, 6.5-9.5Hz), and PA in both age groups. However, the middle-aged rats still showed fewer changes in these parameters during the whole running process. After the waking baseline values were substracted, middle-aged rats showed significantly fewer differences in ΔFrq, ΔTP, and ΔMT but significantly more differences in low-frequency theta activity (4.0-6.5Hz) and HR than the adult rats did. Therefore, the decreasing activity and response of the whole theta band in the middle-aged rats resulted in dominant modulation of the middle to lower frequency (4.0-9.5Hz) theta rhythm. The different alterations in the theta rhythm during treadmill running in the two groups may reflect that learning decline with age. PMID:27496645

  13. Chronic phase advance alters circadian physiological rhythms and peripheral molecular clocks

    PubMed Central

    Wolff, Gretchen; Duncan, Marilyn J.

    2013-01-01

    Shifting the onset of light, acutely or chronically, can profoundly affect responses to infection, tumor progression, development of metabolic disease, and mortality in mammals. To date, the majority of phase-shifting studies have focused on acute exposure to a shift in the timing of the light cycle, whereas the consequences of chronic phase shifts alone on molecular rhythms in peripheral tissues such as skeletal muscle have not been studied. In this study, we tested the effect of chronic phase advance on the molecular clock mechanism in two phenotypically different skeletal muscles. The phase advance protocol (CPA) involved 6-h phase advances (earlier light onset) every 4 days for 8 wk. Analysis of the molecular clock, via bioluminescence recording, in the soleus and flexor digitorum brevis (FDB) muscles and lung demonstrated that CPA advanced the phase of the rhythm when studied immediately after CPA. However, if the mice were placed into free-running conditions (DD) for 2 wk after CPA, the molecular clock was not phase shifted in the two muscles but was still shifted in the lung. Wheel running behavior remained rhythmic in CPA mice; however, the endogenous period length of the free-running rhythm was significantly shorter than that of control mice. Core body temperature, cage activity, and heart rate remained rhythmic throughout the experiment, although the onset of the rhythms was significantly delayed with CPA. These results provide clues that lifestyles associated with chronic environmental desynchrony, such as shift work, can have disruptive effects on the molecular clock mechanism in peripheral tissues, including both types of skeletal muscle. Whether this can contribute, long term, to increased incidence of insulin resistance/metabolic disease requires further study. PMID:23703115

  14. Evaluation of regression-based 3-D shoulder rhythms.

    PubMed

    Xu, Xu; Dickerson, Clark R; Lin, Jia-Hua; McGorry, Raymond W

    2016-08-01

    The movements of the humerus, the clavicle, and the scapula are not completely independent. The coupled pattern of movement of these bones is called the shoulder rhythm. To date, multiple studies have focused on providing regression-based 3-D shoulder rhythms, in which the orientations of the clavicle and the scapula are estimated by the orientation of the humerus. In this study, six existing regression-based shoulder rhythms were evaluated by an independent dataset in terms of their predictability. The datasets include the measured orientations of the humerus, the clavicle, and the scapula of 14 participants over 118 different upper arm postures. The predicted orientations of the clavicle and the scapula were derived from applying those regression-based shoulder rhythms to the humerus orientation. The results indicated that none of those regression-based shoulder rhythms provides consistently more accurate results than the others. For all the joint angles and all the shoulder rhythms, the RMSE are all greater than 5°. Among those shoulder rhythms, the scapula lateral/medial rotation has the strongest correlation between the predicted and the measured angles, while the other thoracoclavicular and thoracoscapular bone orientation angles only showed a weak to moderate correlation. Since the regression-based shoulder rhythm has been adopted for shoulder biomechanical models to estimate shoulder muscle activities and structure loads, there needs to be further investigation on how the predicted error from the shoulder rhythm affects the output of the biomechanical model. PMID:26253991

  15. Circadian rhythm of body temperature during prolonged undersea voyages.

    PubMed

    Colquhoun, W P; Paine, M W; Fort, A

    1978-05-01

    Circadian rhythms of oral temperature were assessed in 12 watchkeepers during a prolonged submarine voyage and compared with a "standard" rhythm obtained from nonwatchkeepers ashore. Initially, the parameters of the rhythms were similar to those of the standard; however, among eight ratings working 4-h watches in a rapidly rotating cycle, considerable changes in the rhythms occurred as the voyage progressed, and concurrent alterations in sleep patterning were observed. The most characteristic change in the rhythm was a marked decline in its amplitude. In most subjects, the rhythm also tended to depart from its original circadian pattern; in at least one case, it effectively disintegrated. One subject's rhythm appeared to "free-run" with a period greater than 24 h. A strong circadian rhythm was maintained in only one of these eight subjects. In four officers whose watch times were at fixed hours, adaptation of the rhythm to unusual times of sleep occurred in 2 of 3 cases where the schedule demanded it. The results are discussed in relation to the design of optimal watchkeeping systems for submariners. PMID:655989

  16. Heart regeneration.

    PubMed

    Breckwoldt, Kaja; Weinberger, Florian; Eschenhagen, Thomas

    2016-07-01

    Regenerating an injured heart holds great promise for millions of patients suffering from heart diseases. Since the human heart has very limited regenerative capacity, this is a challenging task. Numerous strategies aiming to improve heart function have been developed. In this review we focus on approaches intending to replace damaged heart muscle by new cardiomyocytes. Different strategies for the production of cardiomyocytes from human embryonic stem cells or human induced pluripotent stem cells, by direct reprogramming and induction of cardiomyocyte proliferation are discussed regarding their therapeutic potential and respective advantages and disadvantages. Furthermore, different methods for the transplantation of pluripotent stem cell-derived cardiomyocytes are described and their clinical perspectives are discussed. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel. PMID:26597703

  17. Hypoplastic left heart syndrome

    MedlinePlus

    HLHS; Congenital heart - hypoplastic left heart; Cyanotic heart disease - hypoplastic left heart ... Hypoplastic left heart is a rare type of congenital heart disease. It is more common in males than in females. As ...

  18. Release of acetylcholine by chick embryo heart before innervation

    PubMed Central

    Coraboeuf, E.; Le Douarin, G.; Obrecht-Coutris, G.

    1970-01-01

    1. In chick embryo hearts, 3-day-old and not yet innervated, repetitive direct stimulation causes a transitory inhibition of the spontaneous rhythm. 2. The degree of post-stimulation inhibition depends on the frequency and duration of the artificial stimulation and on the concentration of K and Ca ions in the extracellular solution. 3. After treatment with atropine (10-5 g/ml.) post-stimulation inhibition is no longer observed. The spontaneous rhythm is accelerated by atropine. The findings therefore suggest that an ACh-like substance is released from the non-innervated embryonic heart during activity. 4. By use of the dorsal muscle of the leech for biological assay the liberation of an ACh-like substance from the non-innervated embryonic heart was confirmed. ImagesPlate 1 PMID:5498489

  19. Standing down Straight: Jump Rhythm Technique's Rhythm-Driven, Community-Directed Approach to Dance Education

    ERIC Educational Resources Information Center

    Siegenfeld, Billy

    2009-01-01

    "Standing down straight" means to stand on two feet with both stability and relaxation. Using standing down straight as the foundation of class work, Jump Rhythm Technique offers a fresh alternative to conventional systems of dance study. It bases its pedagogy on three behaviors: grounding the body so that it can move with power and efficiency,…

  20. In vitro circadian rhythms: imaging and electrophysiology.

    PubMed

    Beaulé, Christian; Granados-Fuentes, Daniel; Marpegan, Luciano; Herzog, Erik D

    2011-06-30

    In vitro assays have localized circadian pacemakers to individual cells, revealed genetic determinants of rhythm generation, identified molecular players in cell-cell synchronization and determined physiological events regulated by circadian clocks. Although they allow strict control of experimental conditions and reduce the number of variables compared with in vivo studies, they also lack many of the conditions in which cellular circadian oscillators normally function. The present review highlights methods to study circadian timing in cultured mammalian cells and how they have shaped the hypothesis that all cells are capable of circadian rhythmicity. PMID:21819387

  1. In vitro circadian rhythms: imaging and electrophysiology

    PubMed Central

    Beaulé, Christian; Granados-Fuentes, Daniel; Marpegan, Luciano; Herzog, Erik D.

    2013-01-01

    In vitro assays have localized circadian pacemakers to individual cells, revealed genetic determinants of rhythm generation, identified molecular players in cell-cell synchronization and determined physiological events regulated by circadian clocks. Although they allow strict control of experimental conditions and reduce the number of variables compared with in vivo studies, they also lack many of the conditions in which cellular circadian oscillators normally function. The present review highlights methods to study circadian timing in cultured mammalian cells and how they have shaped the hypothesis that all cells are capable of circadian rhythmicity. PMID:21819387

  2. Scapulothoracic rhythm in normal male volunteers.

    PubMed

    Talkhani, I S; Kelly, C P

    1997-01-01

    Dynamic pattern of Scapulothoracic rhythm during arm abduction in scapular plane is studied using computer-imaging technique. Aim of the study is to produce a reproducible and reliable way of calculating the scapular movement and glenohumeral movement using least possible roentgenographic exposure. Moving X-ray screening picture of the shoulder joint is analysed using video capture computer programme and the images at different degrees of abduction are then analysed for scapular movement using computer aided designer and drafting software. Results were comparable to the authoritative shoulder analysis carried out in the past, the difference of radiation exposure, approximately 10 times less. PMID:9603061

  3. Effects of 9-hour time zone changes on fatigue and circadian rhythms of sleep/wake and core temperature

    NASA Technical Reports Server (NTRS)

    Gander, P. H.; Myhre, G.; Graeber, R. C.; Andersen, H. T.; Lauber, J. K.

    1985-01-01

    Physiological and psychological disruptions caused by transmeridian flights may affect the ability of flight crews to meet operational demands. To study these effects, 9 Royal Norwegian Airforces P3-Orion crewmembers flew from Norway to California (-9 hr), and back (+9 hr). Rectal temperature, heart rate and wrist activity were recorded every 2 min, fatigue and mood were rated every 2 hr during the waking day, and logs were kept of sleep times and ratings. Subjects also completed 4 personality inventories. The time-zone shifts produced negative changes in mood which persisted longer after westward flights. Sleep quality (subjective and objective) and duration were slightly disrupted (more after eastward flights). The circadian rhythms of sleep/wake and temperature both completed the 9-hr delay by day 5 in California, although temperature adjusted more slowly. The size of the delay shift was significantly correlated with scores on extraversion and achievement need personality scales. Response to the 9-hr advance were more variable. One subject exhibited a 15-hr delay in his temperature rhythm, and an atypical sleep/nap pattern. On average, the sleep/wake cycle (but not the temperature rhythm), completed the 9-hr advance by the end of the study. Both rhythms adapted more slowly after the eastward flight.

  4. Effects of L-Dopa on circadian rhythms of 6-OHDA striatal lesioned rats: a radiotelemetric study.

    PubMed

    Boulamery, Audrey; Simon, Nicolas; Vidal, Johanna; Bruguerolle, Bernard

    2010-01-01

    Temporal variation in the motor function of Parkinson's disease (PD) patients suggests the potential importance of a chronobiological and chronopharmacological approach in its clinical management. We previously documented the effects of striatal injection of 6-OHDA (as an animal model of PD) on the circadian rhythms of temperature (T), heart rate (HR), and locomotor activity (A). The present work assessed the possible influence of L-Dopa on these same rhythms in the 6-OHDA animal model of PD. The study began after a four-week recovery period following surgical implantation of telemetric devices to monitor the study variables and/or anaesthesia. The study was divided into an initial one-week control period (W1) for baseline measurement of T, HR, and A rhythms. Thereafter, stereotaxic 6-OHDA lesioning was done. and a second monitoring for two weeks followed (W2, W3). Rats were then randomly divided into two groups: eight control rats received, via a mini-osmotic pump implanted subcutaneously, the excipient saline; the other eight rats received L-Dopa (100 mg/kg SC/day). After a seven-day period (W4), the pumps were removed and the T, HR, and A rhythms were monitored for two weeks (W5 and W6). To control for 6-OHDA striatal dopamine-induced depletion, 12 other rats were injected by identical methods (eight rats with 6-OHDA and four controls with saline) and sacrificed at W1, W3, and W5 for dopamine striatal content determination. To verify the delivery of levodopa from the osmotic pumps, plasma levels of levodopa and its main metabolites 3-OMD, DOPAC, and HVA were determined on separate group of rats receiving the drug under the same experimental conditions (osmotic pumps delivering continuously 10 microl/h for seven days, 100 mg/kg/subcutaneously). Our results agree with previously reported rhythmic changes induced by 6-OHDA--loss of circadian rhythmicity or changes in the main parameters of the registered rhythms. When circadian rhythmicity was abolished, L

  5. Atrial rhythm influences catheter tissue contact during radiofrequency catheter ablation of atrial fibrillation: comparison of contact force between sinus rhythm and atrial fibrillation.

    PubMed

    Matsuda, Hisao; Parwani, Abdul Shokor; Attanasio, Philipp; Huemer, Martin; Wutzler, Alexander; Blaschke, Florian; Haverkamp, Wilhelm; Boldt, Leif-Hendrik

    2016-09-01

    Catheter tissue contact force (CF) is an important factor for durable lesion formation during radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). Since CF varies in the beating heart, atrial rhythm during RFCA may influence CF. A high-density map and RFCA points were obtained in 25 patients undergoing RFCA of AF using a CF-sensing catheter (Tacticath, St. Jude Medical). The operators were blinded to the CF information. Contact type was classified into three categories: constant, variable, and intermittent contact. Average CF and contact type were analyzed according to atrial rhythm (SR vs. AF) and anatomical location. A total of 1364 points (891 points during SR and 473 points during AF) were analyzed. Average CFs showed no significant difference between SR (17.2 ± 11.3 g) and AF (17.2 ± 13.3 g; p = 0.99). The distribution of points with an average CF of ≥20 and <10 g also showed no significant difference. However, the distribution of excessive CF (CF ≥40 g) was significantly higher during AF (7.4 %) in comparison with SR (4.2 %; p < 0.05). At the anterior area of the right inferior pulmonary vein (RIPV), the average CF during AF was significantly higher than during SR (p < 0.05). Constant contact was significantly higher during AF (32.2 %) when compared to SR (9.9 %; p < 0.01). Although the average CF was not different between atrial rhythms, constant contact was more often achievable during AF than it was during SR. However, excessive CF also seems to occur more frequently during AF especially at the anterior part of RIPV. PMID:26498938

  6. Heart Failure

    MedlinePlus

    ... blood the way it should. It can affect one or both sides of the heart. The weakening of the heart's pumping ability causes Blood and fluid to back up into the lungs The buildup of fluid in the feet, ankles and legs - called edema Tiredness and shortness of breath Common causes of ...

  7. Having Heart.

    PubMed

    Cochrane, Christine

    2015-01-01

    A heart comes in many forms. This article shares the experience of behavioral health nurses caring for a suicidal patient who needs a heart. As a team, the nurses and their patient shared the journey of what it takes to achieve an optimum quality of life with a left ventricular assist device (LVAD) while battling mental illness. PMID:26731919

  8. Temperature compensation and entrainment in circadian rhythms

    NASA Astrophysics Data System (ADS)

    Bodenstein, C.; Heiland, I.; Schuster, S.

    2012-06-01

    To anticipate daily variations in the environment and coordinate biological activities into a daily cycle many organisms possess a circadian clock. In the absence of external time cues the circadian rhythm persists with a period of approximately 24 h. The clock phase can be shifted by single pulses of light, darkness, chemicals, or temperature and this allows entrainment of the clock to exactly 24 h by cycles of these zeitgebers. On the other hand, the period of the circadian rhythm is kept relatively constant within a physiological range of constant temperatures, which means that the oscillator is temperature compensated. The mechanisms behind temperature compensation and temperature entrainment are not fully understood, neither biochemically nor mathematically. Here, we theoretically investigate the interplay of temperature compensation and entrainment in general oscillatory systems. We first give an analytical treatment for small temperature shifts and derive that every temperature-compensated oscillator is entrainable to external small-amplitude temperature cycles. Temperature compensation ensures that this entrainment region is always centered at the endogenous period regardless of possible seasonal temperature differences. Moreover, for small temperature cycles the entrainment region of the oscillator is potentially larger for rectangular pulses. For large temperature shifts we numerically analyze different circadian clock models proposed in the literature with respect to these properties. We observe that for such large temperature shifts sinusoidal or gradual temperature cycles allow a larger entrainment region than rectangular cycles.

  9. Melatonin rhythms in Pony mares and foals.

    PubMed

    Kilmer, D M; Sharp, D C; Berglund, L A; Grubaugh, W; McDowell, K J; Peck, L S

    1982-01-01

    Melatonin concentrations in intact (N = 3) and sham-operated (N = 3) mares during March were greater (P less than 0 . 05) during the night than during the day, but this pattern was not seen in 3 mares from which the superior cervical ganglia had been removed bilaterally. When 4 Pony mares were exposed to a photoperiod of 10L:14D for 3 weeks and then to continuous darkness (0L:24D) for another 3 weeks, melatonin levels were greater (P less than 0 . 05) at the end of the 0L:24D period than during the earlier period and still displayed rhythmic fluctuations but were no longer co-ordinated with equivalent day/night rhythms or among mares. When melatonin rhythms were monitored in 3 mares and their foals housed in open pens exposed to natural lighting, significant time trends in melatonin concentrations were observed in mares when the foals were aged 1-3, 4-6 and 7-11 weeks, but foals did not display significant times trends in melatonin until they were 7-11 weeks old. PMID:6962864

  10. Circadian Rhythms, Sleep Deprivation, and Human Performance

    PubMed Central

    Goel, Namni; Basner, Mathias; Rao, Hengyi; Dinges, David F.

    2014-01-01

    Much of the current science on, and mathematical modeling of, dynamic changes in human performance within and between days is dominated by the two-process model of sleep–wake regulation, which posits a neurobiological drive for sleep that varies homeostatically (increasing as a saturating exponential during wakefulness and decreasing in a like manner during sleep), and a circadian process that neurobiologically modulates both the homeostatic drive for sleep and waking alertness and performance. Endogenous circadian rhythms in neurobehavioral functions, including physiological alertness and cognitive performance, have been demonstrated using special laboratory protocols that reveal the interaction of the biological clock with the sleep homeostatic drive. Individual differences in circadian rhythms and genetic and other components underlying such differences also influence waking neurobehavioral functions. Both acute total sleep deprivation and chronic sleep restriction increase homeostatic sleep drive and degrade waking neurobehavioral functions as reflected in sleepiness, attention, cognitive speed, and memory. Recent evidence indicating a high degree of stability in neurobehavioral responses to sleep loss suggests that these trait-like individual differences are phenotypic and likely involve genetic components, including circadian genes. Recent experiments have revealed both sleep homeostatic and circadian effects on brain metabolism and neural activation. Investigation of the neural and genetic mechanisms underlying the dynamically complex interaction between sleep homeostasis and circadian systems is beginning. A key goal of this work is to identify biomarkers that accurately predict human performance in situations in which the circadian and sleep homeostatic systems are perturbed. PMID:23899598

  11. The effect of stress on circadian rhythms.

    PubMed

    Brodan, V; Kuhn, E; Veselková, A; Kaucká, J

    1982-01-01

    The authors chose four types of intensive stress in man and show their effect on the circadian rhythms of selected parameters. Sleep deprivation reduces mean sideraemia and oscilation amplitudes. The morning rhythm maximum shifts to early morning hours. Acute fasting does not change the biorhythm of serum iron despite that mean sideraemia increases. On the other hand, realimentation is associated with a marked drop of iron level and a shift of the morning maximum to early afternoon hours. Stress induced by isolation in humid warm environment initiates a decrease of systolic blood pressure. While biorhythm amplitude remains unchanged peak systolic pressure moves from the usual 18 to 20 hours up to 23 to 24 hours. Stress caused by diagnostic cardiac catheterization results in biorhythm inversion of the urinary excretion of catecholamines and 17-OH-corticoids. On the day of catheterization, performed in all cases in the morning hours, the usual morning peak values of adrenaline shifted to afternoon hours and those of noradrenaline and 17-OH-corticoids even to late night hours. For practical purposes, biorhythm changes can be used as indicators of the effect and intensity of stress. PMID:7075389

  12. Rhythms for Cognition: Communication through Coherence.

    PubMed

    Fries, Pascal

    2015-10-01

    I propose that synchronization affects communication between neuronal groups. Gamma-band (30-90 Hz) synchronization modulates excitation rapidly enough that it escapes the following inhibition and activates postsynaptic neurons effectively. Synchronization also ensures that a presynaptic activation pattern arrives at postsynaptic neurons in a temporally coordinated manner. At a postsynaptic neuron, multiple presynaptic groups converge, e.g., representing different stimuli. If a stimulus is selected by attention, its neuronal representation shows stronger and higher-frequency gamma-band synchronization. Thereby, the attended stimulus representation selectively entrains postsynaptic neurons. The entrainment creates sequences of short excitation and longer inhibition that are coordinated between pre- and postsynaptic groups to transmit the attended representation and shut out competing inputs. The predominantly bottom-up-directed gamma-band influences are controlled by predominantly top-down-directed alpha-beta-band (8-20 Hz) influences. Attention itself samples stimuli at a 7-8 Hz theta rhythm. Thus, several rhythms and their interplay render neuronal communication effective, precise, and selective. PMID:26447583

  13. Circadian rhythm and its role in malignancy

    PubMed Central

    2010-01-01

    Circadian rhythms are daily oscillations of multiple biological processes directed by endogenous clocks. The circadian timing system comprises peripheral oscillators located in most tissues of the body and a central pacemaker located in the suprachiasmatic nucleus (SCN) of the hypothalamus. Circadian genes and the proteins produced by these genes constitute the molecular components of the circadian oscillator which form positive/negative feedback loops and generate circadian rhythms. The circadian regulation extends beyond clock genes to involve various clock-controlled genes (CCGs) including various cell cycle genes. Aberrant expression of circadian clock genes could have important consequences on the transactivation of downstream targets that control the cell cycle and on the ability of cells to undergo apoptosis. This may lead to genomic instability and accelerated cellular proliferation potentially promoting carcinogenesis. Different lines of evidence in mice and humans suggest that cancer may be a circadian-related disorder. The genetic or functional disruption of the molecular circadian clock has been found in various cancers including breast, ovarian, endometrial, prostate and hematological cancers. The acquisition of current data in circadian clock mechanism may help chronotherapy, which takes into consideration the biological time to improve treatments by devising new therapeutic approaches for treating circadian-related disorders, especially cancer. PMID:20353609

  14. Subjective pain perception mediated by alpha rhythms.

    PubMed

    Peng, Weiwei; Babiloni, Claudio; Mao, Yanhui; Hu, Yong

    2015-07-01

    Suppression of spontaneous alpha oscillatory activities, interpreted as cortical excitability, was observed in response to both transient and tonic painful stimuli. The changes of alpha rhythms induced by pain could be modulated by painful sensory inputs, experimental tasks, and top-down cognitive regulations such as attention. The temporal and spatial characteristics, as well as neural functions of pain induced alpha responses, depend much on how these factors contribute to the observed alpha event-related desynchronization/synchronization (ERD/ERS). How sensory-, task-, and cognitive-related changes of alpha oscillatory activities interact in pain perception process is reviewed in the current study, and the following conclusions are made: (1) the functional inhibition hypothesis that has been proposed in auditory and visual modalities could be applied also in pain modality; (2) the neural functions of pain induced alpha ERD/ERS were highly dependent on the cortical regions where it is observed, e.g., somatosensory cortex alpha ERD/ERS in pain perception for painful stimulus processing; (3) the attention modulation of pain perception, i.e., influences on the sensory and affective dimensions of pain experience, could be mediated by changes of alpha rhythms. Finally, we propose a model regarding the determinants of pain related alpha oscillatory activity, i.e., sensory-discriminative, affective-motivational, and cognitive-modulative aspects of pain experience, would affect and determine pain related alpha oscillatory activities in an integrated way within the distributed alpha system. PMID:26026894

  15. Circadian Activity Rhythms, Time Urgency, and Achievement Concerns.

    ERIC Educational Resources Information Center

    Watts, Barbara L.

    Many physiological and psychological processes fluctuate throughout the day in fairly stable, rhythmic patterns. The relationship between individual differences in circadian activity rhythms and a sense of time urgency were explored as well as a number of achievement-related variables. Undergraduates (N=308), whose circadian activity rhythms were…

  16. Neglect of Biological Rhythms in High School Biology Texts.

    ERIC Educational Resources Information Center

    Ahlgren, Andrew; Nelson, Julie Ann

    1979-01-01

    This article developed from a survey of the five most popular biology texts which promote the theory of invariant homeostasis rather than biological rhythms. The popular fad of "birthdate biorhythms" is discussed in relation to providing education on biological rhythms and its legitimacy to the public. (SA)

  17. A novel animal model linking adiposity to altered circadian rhythms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Researchers have provided evidence for a link between obesity and altered circadian rhythms (e.g., shift work, disrupted sleep), but the mechanism for this association is still unknown. Adipocytes possess an intrinsic circadian clock, and circadian rhythms in adipocytokines and adipose tissue metab...

  18. Rhythm's Gonna Get You: Regular Meter Facilitates Semantic Sentence Processing

    ERIC Educational Resources Information Center

    Rothermich, Kathrin; Schmidt-Kassow, Maren; Kotz, Sonja A.

    2012-01-01

    Rhythm is a phenomenon that fundamentally affects the perception of events unfolding in time. In language, we define "rhythm" as the temporal structure that underlies the perception and production of utterances, whereas "meter" is defined as the regular occurrence of beats (i.e. stressed syllables). In stress-timed languages such as German, this…

  19. Yes, circadian rhythms actually do affect almost everything.

    PubMed

    Dunlap, Jay C; Loros, Jennifer J

    2016-07-01

    Circadian rhythms in the level of intracellular Mg appear to be widely conserved phylogenetically, and have the potential to impact nearly all aspects of metabolism. Moreover, the clock regulates the ion channels that generate the rhythm, demonstrating that the whole cell operates as a circadian system. PMID:27241553

  20. A Rhythm Recognition Computer Program to Advocate Interactivist Perception

    ERIC Educational Resources Information Center

    Buisson, Jean-Christophe

    2004-01-01

    This paper advocates the main ideas of the interactive model of representation of Mark Bickhard and the assimilation/accommodation framework of Jean Piaget, through a rhythm recognition demonstration program. Although completely unsupervised, the program progressively learns to recognize more and more complex rhythms struck on the user's keyboard.…

  1. Effects of Some Aspects of Rhythm on Tempo Perception.

    ERIC Educational Resources Information Center

    Wang, Cecilia Chu

    1984-01-01

    Results indicated that significantly more time is needed to perceive tempo increase than tempo decrease, uneven rhythm then even rhythm, and melody alone than melody with accompaniment. Furthermore, significant interaction effects involving beat locations of tempo change suggest that differential groupings may be a factor in tempo discrimination.…

  2. Perceptual Tests of Rhythmic Similarity: II. Syllable Rhythm

    ERIC Educational Resources Information Center

    Kim, Jeesun; Davis, Chris; Cutler, Anne

    2008-01-01

    To segment continuous speech into its component words, listeners make use of language rhythm; because rhythm differs across languages, so do the segmentation procedures which listeners use. For each of stress-, syllable-and mora-based rhythmic structure, perceptual experiments have led to the discovery of corresponding segmentation procedures. In…

  3. Dissociable systems of working memory for rhythm and melody.

    PubMed

    Jerde, Trenton A; Childs, Stephanie K; Handy, Sarah T; Nagode, Jennifer C; Pardo, José V

    2011-08-15

    Specialized neural systems are engaged by the rhythmic and melodic components of music. Here, we used PET to measure regional cerebral blood flow (rCBF) in a working memory task for sequences of rhythms and melodies, which were presented in separate blocks. Healthy subjects, without musical training, judged whether a target rhythm or melody was identical to a series of subsequently presented rhythms or melodies. When contrasted with passive listening to rhythms, working memory for rhythm activated the cerebellar hemispheres and vermis, right anterior insular cortex, and left anterior cingulate gyrus. These areas were not activated in a contrast between passive listening to rhythms and a non-auditory control, indicating their role in the temporal processing that was specific to working memory for rhythm. The contrast between working memory for melody and passive listening to melodies activated mainly a right-hemisphere network of frontal, parietal, and temporal cortices: areas involved in pitch processing and auditory working memory. Overall, these results demonstrate that rhythm and melody have unique neural signatures not only in the early stages of auditory processing, but also at the higher cognitive level of working memory. PMID:21645625

  4. Daily Rhythms in Mosquitoes and Their Consequences for Malaria Transmission.

    PubMed

    Rund, Samuel S C; O'Donnell, Aidan J; Gentile, James E; Reece, Sarah E

    2016-01-01

    The 24-h day involves cycles in environmental factors that impact organismal fitness. This is thought to select for organisms to regulate their temporal biology accordingly, through circadian and diel rhythms. In addition to rhythms in abiotic factors (such as light and temperature), biotic factors, including ecological interactions, also follow daily cycles. How daily rhythms shape, and are shaped by, interactions between organisms is poorly understood. Here, we review an emerging area, namely the causes and consequences of daily rhythms in the interactions between vectors, their hosts and the parasites they transmit. We focus on mosquitoes, malaria parasites and vertebrate hosts, because this system offers the opportunity to integrate from genetic and molecular mechanisms to population dynamics and because disrupting rhythms offers a novel avenue for disease control. PMID:27089370

  5. The role of circadian rhythm in breast cancer

    PubMed Central

    Li, Shujing; Ao, Xiang

    2013-01-01

    The circadian rhythm is an endogenous time keeping system shared by most organisms. The circadian clock is comprised of both peripheral oscillators in most organ tissues of the body and a central pacemaker located in the suprachiasmatic nucleus (SCN) of the central nervous system. The circadian rhythm is crucial in maintaining the normal physiology of the organism including, but not limited to, cell proliferation, cell cycle progression, and cellular metabolism; whereas disruption of the circadian rhythm is closely related to multi-tumorigenesis. In the past several years, studies from different fields have revealed that the genetic or functional disruption of the molecular circadian rhythm has been found in various cancers, such as breast, prostate, and ovarian. In this review, we will investigate and present an overview of the current research on the influence of circadian rhythm regulating proteins on breast cancer. PMID:23997531

  6. Daily Rhythms in Mosquitoes and Their Consequences for Malaria Transmission

    PubMed Central

    Rund, Samuel S. C.; O’Donnell, Aidan J.; Gentile, James E.; Reece, Sarah E.

    2016-01-01

    The 24-h day involves cycles in environmental factors that impact organismal fitness. This is thought to select for organisms to regulate their temporal biology accordingly, through circadian and diel rhythms. In addition to rhythms in abiotic factors (such as light and temperature), biotic factors, including ecological interactions, also follow daily cycles. How daily rhythms shape, and are shaped by, interactions between organisms is poorly understood. Here, we review an emerging area, namely the causes and consequences of daily rhythms in the interactions between vectors, their hosts and the parasites they transmit. We focus on mosquitoes, malaria parasites and vertebrate hosts, because this system offers the opportunity to integrate from genetic and molecular mechanisms to population dynamics and because disrupting rhythms offers a novel avenue for disease control. PMID:27089370

  7. Renal electrolyte circadian rhythms - Independence from feeding and activity patterns

    NASA Technical Reports Server (NTRS)

    Moore-Ede, M. C.; Herd, J. A.

    1977-01-01

    Experiments were conducted on six unanesthetized chair-acclimatized adult male squirrel monkeys (Saimiri sciureus) weighing 600-900 g to determine whether internal synchronization is the result of simple passive dependence of renal excretory rhythms on endogenous rhythms of those variable that influence electrolyte excretion such as dietary intake and muscular activity. Independence of the urinary rhythms from diurnal variations in feeding, drinking, and activity was secured by depriving the animals of food, water, and training them to perform a two-hourly schedule of feeding, drinking, and activity throughout day and night. Results indicate that the internal synchronization which is normally observed between the behavioral and urinary rhythms cannot be explained by any direct dependence of renal function on behavioral patterns. The most probable mechanism for circadian internal synchronization is that the various behavioral and renal rhythms are controlled by potentially independent separate oscillators which are normally kept in synchrony with one another.

  8. Circadian rhythms in the short-tailed shrew, Blarina brevicauda.

    PubMed

    Antipas, A J; Madison, D M; Ferraro, J S

    1990-08-01

    Circadian rhythms of wheel running and feeding were measured in the short-tailed shrew. Shrews were strongly nocturnal, and their activity rhythms entrained to both long-day (LD 16:8) and short-day (LD 6:18) photocycles. Under conditions of continuous light (LL) or darkness (DD), the activity rhythms free-ran with average periodicities of 25.1 hours and 24.1 hours, respectively. In LL the level of activity was depressed, and in some cases wheel running was completely inhibited. No significant sex differences were observed in the period or amplitude of the monitored circadian rhythms. All shrews fed throughout the day and night; however, unlike in previous reports, ultradian periods of feeding behavior were not found. The results are related to Aschoff's four observations for the effect of light on activity rhythms in nocturnal rodents. PMID:2255728

  9. The impact of yoga on atrial fibrillation: A review of The Yoga My Heart Study

    PubMed Central

    Deutsch, Steven Brent; Krivitsky, Eric Lawrence

    2015-01-01

    Atrial fibrillation is a common arrhythmia affecting thousands of individuals worldwide. It is a conduction disorder that causes the heart to beat irregularly and rapidly. There are a few medical approaches to manage this costly health care burden: antiarrhythmics to maintain normal sinus rhythm, beta blockers to achieve rate control while allowing atrial fibrillation to persist, and electro-physiologic intervention for rate and rhythm control. These treatments can be costly and are not without side effects. Yoga, an intervention that is available to people worldwide, has shown some promise in combating this widespread heart disorder. PMID:26702311

  10. Chronotype predicts positive affect rhythms measured by ecological momentary assessment.

    PubMed

    Miller, Megan A; Rothenberger, Scott D; Hasler, Brant P; Donofry, Shannon D; Wong, Patricia M; Manuck, Stephen B; Kamarck, Thomas W; Roecklein, Kathryn A

    2015-04-01

    Evening chronotype, a correlate of delayed circadian rhythms, is associated with depression. Altered positive affect (PA) rhythms may mediate the association between evening chronotype and depression severity. Consequently, a better understanding of the relationship between chronotype and PA may aid in understanding the etiology of depression. Recent studies have found that individuals with evening chronotype show delayed and blunted PA rhythms, although these studies are relatively limited in sample size, representativeness and number of daily affect measures. Further, published studies have not included how sleep timing changes on workday and non-workdays, or social jet lag (SJL) may contribute to the chronotype-PA rhythm link. Healthy non-depressed adults (n = 408) completed self-report affect and chronotype questionnaires. Subsequently, positive and negative affects were measured hourly while awake for at least two workdays and one non-workday by ecological momentary assessment (EMA). Sleep variables were collected via actigraphy and compared across chronotype groups. A cosinor variant of multilevel modeling was used to model individual and chronotype group rhythms and to calculate two variables: (1) amplitude of PA, or the absolute amount of daily variation from peak to trough during one period of the rhythm and (2) acrophase, or the time at which the peak amplitude of affect rhythms occurred. On workdays, individuals with evening chronotype had significantly lower PA amplitudes and later workday acrophase times than their morning type counterparts. In contrast to predictions, SJL was not found to be a mediator in the relationship between chronotype and PA rhythms. The association of chronotype and PA rhythms in healthy adults may suggest the importance of daily measurement of PA in depressed individuals and would be consistent with the hypothesis that evening chronotype may create vulnerability to depression via delayed and blunted PA rhythms. PMID

  11. Cross-cultural influences on rhythm processing: reproduction, discrimination, and beat tapping

    PubMed Central

    Cameron, Daniel J.; Bentley, Jocelyn; Grahn, Jessica A.

    2015-01-01

    The structures of musical rhythm differ between cultures, despite the fact that the ability to entrain movement to musical rhythm occurs in virtually all individuals across cultures. To measure the influence of culture on rhythm processing, we tested East African and North American adults on perception, production, and beat tapping for rhythms derived from East African and Western music. To assess rhythm perception, participants identified whether pairs of rhythms were the same or different. To assess rhythm production, participants reproduced rhythms after hearing them. To assess beat tapping, participants tapped the beat along with repeated rhythms. We expected that performance in all three tasks would be influenced by the culture of the participant and the culture of the rhythm. Specifically, we predicted that a participant’s ability to discriminate, reproduce, and accurately tap the beat would be better for rhythms from their own culture than for rhythms from another culture. In the rhythm discrimination task, there were no differences in discriminating culturally familiar and unfamiliar rhythms. In the rhythm reproduction task, both groups reproduced East African rhythms more accurately than Western rhythms, but East African participants also showed an effect of cultural familiarity, leading to a significant interaction. In the beat tapping task, participants in both groups tapped the beat more accurately for culturally familiar than for unfamiliar rhythms. Moreover, there were differences between the two participant groups, and between the two types of rhythms, in the metrical level selected for beat tapping. The results demonstrate that culture does influence the processing of musical rhythm. In terms of the function of musical rhythm, our results are consistent with theories that musical rhythm enables synchronization. Musical rhythm may foster musical cultural identity by enabling within-group synchronization to music, perhaps supporting social cohesion

  12. Seasonal changes of 24-hour intraocular pressure rhythm in healthy Shanghai population

    PubMed Central

    Cheng, Jingyi; Xiao, Ming; Xu, Huan; Fang, Shaobin; Chen, Xu; Kong, Xiangmei; Sun, Xinghuai

    2016-01-01

    Abstract The aim of the present study was to investigate and compare the 24-hour intraocular pressure (IOP) rhythms in winter and summer in the healthy population of Shanghai, China. This is a cross-sectional study in which 24-hour IOP measurements were taken for all eligible healthy volunteers in winter and summer, respectively, and the temperature, hours of sunlight (sunlight time), and circulatory parameters, including heart rate, systolic blood pressure, and diastolic blood pressure, were also recorded. The 24-hour IOP curves and IOP parameters (mean, peak, trough, and fluctuation of IOP together with the diurnal-to-nocturnal IOP change) in winter and summer were obtained and compared. The magnitude of IOP changes from summer to winter was also calculated. A total of 29 participants (58 eyes), 14 (48.28%) male and 15 (51.72%) female, aged 43.66 ± 12.20 (19–61) years, were considered eligible for this study. Generally, IOP decreased progressively before noon, increased notably in the nocturnal period, and peaked at 12:00 am in winter and at 2:00 am in summer. The pattern of 24-hour IOP in winter and summer was significantly different (P = 0.002). The average IOPs from 4:00 pm to 8:00 am, except for 6:00 am, were significantly higher in winter (P < 0.05). However, no significant differences were shown after adjusting for temperature and/or sunlight time. From summer to winter, the extent of IOP increase was mostly around 0 to 3 mm Hg, and the IOPs increased more significantly in the nocturnal period than in the diurnal period (P = 0.05). The 24-hour IOP rhythms were different in winter and summer, with higher IOP level in winter. Temperature and sunlight time, which are independent of heart rate and blood pressure, affected the 24-hour IOP rhythms in healthy people in Shanghai, China. Further investigations are expected for the rhythm of some endogenous substance secretion and the inner mechanism of regulation of IOP. PMID:27495076

  13. Seasonal changes of 24-hour intraocular pressure rhythm in healthy Shanghai population.

    PubMed

    Cheng, Jingyi; Xiao, Ming; Xu, Huan; Fang, Shaobin; Chen, Xu; Kong, Xiangmei; Sun, Xinghuai

    2016-08-01

    The aim of the present study was to investigate and compare the 24-hour intraocular pressure (IOP) rhythms in winter and summer in the healthy population of Shanghai, China.This is a cross-sectional study in which 24-hour IOP measurements were taken for all eligible healthy volunteers in winter and summer, respectively, and the temperature, hours of sunlight (sunlight time), and circulatory parameters, including heart rate, systolic blood pressure, and diastolic blood pressure, were also recorded. The 24-hour IOP curves and IOP parameters (mean, peak, trough, and fluctuation of IOP together with the diurnal-to-nocturnal IOP change) in winter and summer were obtained and compared. The magnitude of IOP changes from summer to winter was also calculated.A total of 29 participants (58 eyes), 14 (48.28%) male and 15 (51.72%) female, aged 43.66 ± 12.20 (19-61) years, were considered eligible for this study. Generally, IOP decreased progressively before noon, increased notably in the nocturnal period, and peaked at 12:00 AM in winter and at 2:00 AM in summer. The pattern of 24-hour IOP in winter and summer was significantly different (P = 0.002). The average IOPs from 4:00 PM to 8:00 AM, except for 6:00 AM, were significantly higher in winter (P < 0.05). However, no significant differences were shown after adjusting for temperature and/or sunlight time. From summer to winter, the extent of IOP increase was mostly around 0 to 3 mm Hg, and the IOPs increased more significantly in the nocturnal period than in the diurnal period (P = 0.05).The 24-hour IOP rhythms were different in winter and summer, with higher IOP level in winter. Temperature and sunlight time, which are independent of heart rate and blood pressure, affected the 24-hour IOP rhythms in healthy people in Shanghai, China. Further investigations are expected for the rhythm of some endogenous substance secretion and the inner mechanism of regulation of IOP. PMID:27495076

  14. Interpersonal and social rhythm therapy: an intervention addressing rhythm dysregulation in bipolar disorder

    PubMed Central

    Frank, Ellen; Swartz, Holly A.; Boland, Elaine

    2007-01-01

    Bipolar disorder is characterized by frequent recurrences, often related to noncompliance with drug treatment, stressful life events, and disruptions in social rhythms. Interpersonal and social rhythm therapy (IPSRT) was designed to directly address these problem areas. This article discusses the circadian basis of IPSRT and the importance of stable daily routines in the maintenance of the euthymic state, as well as the two large controlled trials which empirically support this intervention. The authors discuss the advantages of IPSRT as an acute intervention, as well as a prophylactic treatment for both bipolar I and II disorder. Using a case example, the authors describe how IPSRT is implemented in a clinical setting, detailing the therapeutic methods and processes involved. PMID:17969869

  15. Role of Circadian Rhythms in Potassium Homeostasis

    PubMed Central

    Gumz, Michelle L.; Rabinowitz, Lawrence

    2013-01-01

    It has been known for decades that urinary potassium excretion varies with a circadian pattern. In this review, we consider the historical evidence for this phenomenon and present an overview of recent developments in the field. Extensive evidence from the latter part of the last century clearly demonstrates that circadian potassium excretion does not depend on endogenous aldosterone. Of note is the recent discovery that the expression of several renal potassium transporters varies with a circadian pattern that appears to be consistent with substantial clinical data regarding daily fluctuations in urinary potassium levels. We propose the circadian clock mechanism as a key regulator of renal potassium transporters, and consequently renal potassium excretion. Further investigation into the mechanism of regulation of renal potassium transport by the circadian clock is warranted in order to increase our understanding of the clinical relevance of circadian rhythms to potassium homeostasis. PMID:23953800

  16. Copula-based analysis of rhythm

    NASA Astrophysics Data System (ADS)

    García, J. E.; González-López, V. A.; Viola, M. L. Lanfredi

    2016-06-01

    In this paper we establish stochastic profiles of the rhythm for three languages: English, Japanese and Spanish. We model the increase or decrease of the acoustical energy, collected into three bands coming from the acoustic signal. The number of parameters needed to specify a discrete multivariate Markov chain grows exponentially with the order and dimension of the chain. In this case the size of the database is not large enough for a consistent estimation of the model. We apply a strategy to estimate a multivariate process with an order greater than the order achieved using standard procedures. The new strategy consist on obtaining a partition of the state space which is constructed from a combination of the partitions corresponding to the three marginal processes, one for each band of energy, and the partition coming from to the multivariate Markov chain. Then, all the partitions are linked using a copula, in order to estimate the transition probabilities.

  17. Sensorimotor Rhythm Neurofeedback Enhances Golf Putting Performance.

    PubMed

    Cheng, Ming Yang; Huang, Chung Ju; Chang, Yu Kai; Koester, Dirk; Schack, Thomas; Hung, Tsung Min

    2015-12-01

    Sensorimotor rhythm (SMR) activity has been related to automaticity during skilled action execution. However, few studies have bridged the causal link between SMR activity and sports performance. This study investigated the effect of SMR neurofeedback training (SMR NFT) on golf putting performance. We hypothesized that preelite golfers would exhibit enhanced putting performance after SMR NFT. Sixteen preelite golfers were recruited and randomly assigned into either an SMR or a control group. Participants were asked to perform putting while electroencephalogram (EEG) was recorded, both before and after intervention. Our results showed that the SMR group performed more accurately when putting and exhibited greater SMR power than the control group after 8 intervention sessions. This study concludes that SMR NFT is effective for increasing SMR during action preparation and for enhancing golf putting performance. Moreover, greater SMR activity might be an EEG signature of improved attention processing, which induces superior putting performance. PMID:26866770

  18. Unstable periodic orbits in human cardiac rhythms

    NASA Astrophysics Data System (ADS)

    Narayanan, K.; Govindan, R. B.; Gopinathan, M. S.

    1998-04-01

    Unstable periodic orbits (UPOs) extracted from experimental electrocardiograph signals are reported for normal and pathological human cardiac rhythms. The periodicity and distribution of the orbits on the chaotic attractor are found to be indicative of the state of health of the cardiac system. The normal cardiac system is characterized by three to four UPOs with typical periodicities and intensities. However, pathological conditions such as premature ventricular contraction, atrio ventricular block, ventricular tachy arrhythmia, and ventricular fibrillation have UPOs whose periodicity and intensity distribution are quite distinct from those of the healthy cases and are characteristic of the pathological conditions. Eigenvalues and the largest positive Lyapunov exponent value for the UPOs are also reported. The UPOs are shown to be insensitive to the embedding dimension and the present UPO analysis is demonstrated to be reliable by the method of surrogate analysis.

  19. Cardiovascular rhythms in the 0.15-Hz band: common origin of identical phenomena in man and dog in the reticular formation of the brain stem?

    PubMed

    Perlitz, Volker; Lambertz, Manfred; Cotuk, Birol; Grebe, Reinhard; Vandenhouten, Ralf; Flatten, Guido; Petzold, Ernst Richard; Schmid-Schönbein, Holger; Langhorst, Peter

    2004-09-01

    Selected examples from experiments in humans and dogs with time series of reticular neurons, respiration, arterial blood pressure and cutaneous forehead blood content fluctuations were analysed using multiscaled time-frequency distribution, post-event-scan and pointwise transinformation. We found in both experiments a "0.15-Hz rhythm" exhibiting periods of spindle waves (increasing and decreasing amplitudes), phase synchronized with respiration at 1:2 and 1:1 integer number ratios. At times of wave-epochs and n:m phase synchronization, the 0.15-Hz rhythm appeared in heart rate and arterial blood pressure. As phase synchronization of the 0.15-Hz rhythm with respiration was established at a 1:1 integer number ratio, all cardiovascular-respiratory oscillations were synchronized at 0.15 Hz. Analysis of a canine experiment supplied evidence that the emergence of the 0.15-Hz rhythm and n:m phase synchronization appears to result from a decline in the level of the general activity of the organism associated with a decline in the level of activity of reticular neurons in the lower brainstem network. These findings corroborate the notion of the 0.15-Hz rhythm as a marker of the "trophotropic mode of operation" first introduced by W.R. Hess. PMID:15138824

  20. Heart CT scan

    MedlinePlus

    CAT scan - heart; Computed axial tomography scan - heart; Computed tomography scan - heart; Calcium scoring; Multi-detector CT scan - heart; Electron beam computed tomography - heart; Agaston score; Coronary calcium scan

  1. Coronary heart disease

    MedlinePlus

    Heart disease, Coronary heart disease, Coronary artery disease; Arteriosclerotic heart disease; CHD; CAD ... Coronary heart disease is the leading cause of death in the United States for men and women. Coronary heart ...

  2. Wine and heart health

    MedlinePlus

    Health and wine; Wine and heart disease; Preventing heart disease - wine; Preventing heart disease - alcohol ... more often just to lower your risk of heart disease. Heavier drinking can harm the heart and ...

  3. What Is Heart Failure?

    MedlinePlus

    ... page from the NHLBI on Twitter. What Is Heart Failure? Heart failure is a condition in which the heart can' ... force. Some people have both problems. The term "heart failure" doesn't mean that your heart has stopped ...

  4. Hearts Wish.

    ERIC Educational Resources Information Center

    Jones, Lethonee A.

    1989-01-01

    Investigates characteristics and themes in 102 drawings by sexually abused children. Themes of the drawings included genitalia, the absence of specific body parts, phallic symbols, inappropriate smiles, distorted body images, kinetic activity, prominent hands and fingers, and hearts. (RJC)

  5. Heart palpitations

    MedlinePlus

    Heart palpitations can be due to: Anxiety, stress, panic attack, or fear Caffeine intake Nicotine intake Cocaine or other illegal drugs Diet pills Exercise Fever However, some palpitations are due ...

  6. Heart Failure

    MedlinePlus

    ... together. About Rise Above HF Rise Above Heart Failure seeks to increase the dialogue about HF and improve the lives of people affected by the condition through awareness, education and support. Through the initiative, AHA strives to ...

  7. Heart Transplant

    MedlinePlus

    ... Doctors remove the patient's heart by transecting the aorta , the main pulmonary artery and the superior and ... sewing together the recipient and donor vena cavae, aorta, pulmonary artery and left atrium. In patients with ...

  8. Heart MRI

    MedlinePlus

    ... an imaging method that uses powerful magnets and radio waves to create pictures of the heart. It does ... radiation involved in MRI. The magnetic fields and radio waves used during the scan have not been shown ...

  9. Heart Attack

    MedlinePlus

    ... lower “bad” cholesterol (also called LDL, or low-density lipoprotein) levels and may help increase “good” cholesterol (also called HDL, or high-density lipoprotein). If you have had a heart attack, ...

  10. Heart pacemaker

    MedlinePlus

    ... may not get enough oxygen. Symptoms may be light-headedness, tiredness, fainting spells, and shortness of breath. Some pacemakers can be used to stop a heart rate that is too fast ( tachycardia ) ...

  11. Heart transplant

    MedlinePlus

    ... have symptoms. You must take drugs that prevent transplant rejection for the rest of your life. You will ... heart transplant. The main problem, as with other transplants, is rejection. If rejection can be controlled, survival increases to ...

  12. Circadian rhythms, sleep, and performance in space

    NASA Technical Reports Server (NTRS)

    Mallis, M. M.; DeRoshia, C. W.

    2005-01-01

    Maintaining optimal alertness and neurobehavioral functioning during space operations is critical to enable the National Aeronautics and Space Administration's (NASA's) vision "to extend humanity's reach to the Moon, Mars and beyond" to become a reality. Field data have demonstrated that sleep times and performance of crewmembers can be compromised by extended duty days, irregular work schedules, high workload, and varying environmental factors. This paper documents evidence of significant sleep loss and disruption of circadian rhythms in astronauts and associated performance decrements during several space missions, which demonstrates the need to develop effective countermeasures. Both sleep and circadian disruptions have been identified in the Behavioral Health and Performance (BH&P) area and the Advanced Human Support Technology (AHST) area of NASA's Bioastronautics Critical Path Roadmap. Such disruptions could have serious consequences on the effectiveness, health, and safety of astronaut crews, thus reducing the safety margin and increasing the chances of an accident or incident. These decrements oftentimes can be difficult to detect and counter effectively in restrictive operational environments. NASA is focusing research on the development of optimal sleep/wake schedules and countermeasure timing and application to help mitigate the cumulative effects of sleep and circadian disruption and enhance operational performance. Investing research in humans is one of NASA's building blocks that will allow for both short- and long-duration space missions and help NASA in developing approaches to manage and overcome the human limitations of space travel. In addition to reviewing the current state of knowledge concerning sleep and circadian disruptions during space operations, this paper provides an overview of NASA's broad research goals. Also, NASA-funded research, designed to evaluate the relationships between sleep quality, circadian rhythm stability, and

  13. Circadian rhythms, alcohol and gut interactions

    PubMed Central

    Forsyth, Christopher B.; Voigt, Rbin M.; Burgess, Helen J.; Swanson, Garth R.; Keshavarzian, Ali

    2015-01-01

    The circadian clock establishes rhythms throughout the body with an approximately 24 hour period that affect expression of hundreds of genes. Epidemiological data reveal chronic circadian misalignment, common in our society, significantly increases the risk for a myriad of diseases, including cardiovascular disease, diabetes, cancer, infertility and gastrointestinal disease. Disruption of intestinal barrier function, also known as gut leakiness, is especially important in alcoholic liver disease (ALD). Several studies have shown that alcohol causes ALD in only a 20–30% subset of alcoholics. Thus, a better understanding is needed of why only a subset of alcoholics develops ALD. Compelling evidence shows that increased gut leakiness to microbial products and especially LPS play a critical role in the pathogenesis of ALD. Clock and other circadian clock genes have been shown to regulate lipid transport, motility and other gut functions. We hypothesized that one possible mechanism for alcohol-induced intestinal hyper-permeability is through disruption of central or peripheral (intestinal) circadian regulation. In support of this hypothesis, our recent data shows that disruption of circadian rhythms makes the gut more susceptible to injury. Our in vitro data show that alcohol stimulates increased Clock and Per2 circadian clock proteins and that siRNA knockdown of these proteins prevents alcohol-induced permeability. We also show that intestinal Cyp2e1-mediated oxidative stress is required for alcohol-induced upregulation of Clock and Per2 and intestinal hyperpermeability. Our mouse model of chronic alcohol feeding shows that circadian disruption through genetics (in ClockΔ19 mice) or environmental disruption by weekly 12h phase shifting results in gut leakiness alone and exacerbates alcohol-induced gut leakiness and liver pathology. Our data in human alcoholics show they exhibit abnormal melatonin profiles characteristic of circadian disruption. Taken together our

  14. Circadian rhythms, sleep, and performance in space.

    PubMed

    Mallis, M M; DeRoshia, C W

    2005-06-01

    Maintaining optimal alertness and neurobehavioral functioning during space operations is critical to enable the National Aeronautics and Space Administration's (NASA's) vision "to extend humanity's reach to the Moon, Mars and beyond" to become a reality. Field data have demonstrated that sleep times and performance of crewmembers can be compromised by extended duty days, irregular work schedules, high workload, and varying environmental factors. This paper documents evidence of significant sleep loss and disruption of circadian rhythms in astronauts and associated performance decrements during several space missions, which demonstrates the need to develop effective countermeasures. Both sleep and circadian disruptions have been identified in the Behavioral Health and Performance (BH&P) area and the Advanced Human Support Technology (AHST) area of NASA's Bioastronautics Critical Path Roadmap. Such disruptions could have serious consequences on the effectiveness, health, and safety of astronaut crews, thus reducing the safety margin and increasing the chances of an accident or incident. These decrements oftentimes can be difficult to detect and counter effectively in restrictive operational environments. NASA is focusing research on the development of optimal sleep/wake schedules and countermeasure timing and application to help mitigate the cumulative effects of sleep and circadian disruption and enhance operational performance. Investing research in humans is one of NASA's building blocks that will allow for both short- and long-duration space missions and help NASA in developing approaches to manage and overcome the human limitations of space travel. In addition to reviewing the current state of knowledge concerning sleep and circadian disruptions during space operations, this paper provides an overview of NASA's broad research goals. Also, NASA-funded research, designed to evaluate the relationships between sleep quality, circadian rhythm stability, and

  15. Circadian Rhythms in Acute Intermittent Porphyria—a Pilot Study

    PubMed Central

    Larion, Sebastian; Caballes, F. Ryan; Hwang, Sun-Il; Lee, Jin-Gyun; Rossman, Whitney Ellefson; Parsons, Judy; Steuerwald, Nury; Li, Ting; Maddukuri, Vinaya; Groseclose, Gale; Finkielstein, Carla V.; Bonkovsky, Herbert L.

    2013-01-01

    Acute intermittent porphyria (AIP) is an inherited disorder of heme synthesis wherein a partial deficiency of porphobilinogen [PBG] deaminase [PBGD], with other factors may give rise to biochemical and clinical manifestations of disease. The biochemical hallmarks of active AIP are relative hepatic heme deficiency and uncontrolled up-regulation of hepatic 5-aminolevulinic acid [ALA] synthase-1 [ALAS1] with overproduction of ALA and PBG. The treatment of choice is intravenous heme, which restores the deficient regulatory heme pool of the liver and represses ALAS1. Recently, heme has been shown to influence circadian rhythms by controlling their negative feedback loops. We evaluated whether subjects with AIP exhibited an altered circadian profile. Over a 21 h period, we measured levels of serum cortisol, melatonin, ALA, PBG, and mRNA levels [in peripheral blood mononuclear cells] of selected clock-controlled genes and genes involved in heme synthesis in 10 Caucasian [European-American] women who were either post-menopausal or had been receiving female hormone therapy, 6 of whom have AIP and 4 do not and are considered controls. Four AIP subjects with biochemical activity exhibited higher levels of PBG and lower levels and dampened oscillation of serum cortisol, and a trend for lower levels of serum melatonin, than controls or AIP subjects without biochemical activity. Levels of clock-controlled gene mRNAs showed significant increases over baseline in all subjects at 5 am and 11 pm, whereas mRNA levels of ALAS1, ALAS2, and PBGD were increased only at 11 pm in subjects with active AIP. This pilot study provides evidence for disturbances of circadian markers in women with active AIP that may trigger or sustain some common clinical features of AIP. PMID:23650938

  16. [The kidney and circadian rhythms: a whole new world?].

    PubMed

    Manfredini, Roberto; Sasso, Ferdinando Carlo; Pala, Marco; De Giorgi, Alfredo; Fabbian, Fabio

    2013-01-01

    Chronobiology is a branch of biomedical sciences devoted to the study of biological rhythms. Biological rhythms exist at any level of living organisms and, according to their cycle length, may be divided into three main types: circadian, ultradian, and infradian rhythms. Circadian rhythms are the most commonly and widely studied. The principal circadian clock is located in the suprachiasmatic nucleus of the hypothalamus, and is supposed to regulate peripheral clocks via neurohumoral modulation. Circadian clocks have been identified within almost all mammalian cell types, and circadian clock genes seem to be essential for cardiovascular health. Disturbance of the renal circadian rhythms is increasingly recognized as a risk factor for hypertension, polyuria, and other diseases and may contribute to renal fibrosis. The origin of these rhythms has been attributed to the reactive response of the kidney to circadian changes in volume and/or in the composition of extracellular fluids regulated by rest/activity and feeding/fasting cycles. However, most of the renal excretory rhythms persist for long periods of time, even in the absence of periodic environmental cues. These observations led to the hypothesis of the existence of a self-sustained mechanism, enabling the kidney to anticipate various predictable circadian challenges to homeostasis. The molecular basis of this mechanism remained unknown until the recent discovery of the mammalian circadian clock, comprising a system of autoregulatory transcriptional/translational feedback loops, which have also been found in the kidney. PMID:24403200

  17. Vasoactive intestinal polypeptide entrains circadian rhythms in astrocytes.

    PubMed

    Marpegan, Luciano; Krall, Thomas J; Herzog, Erik D

    2009-04-01

    Many mammalian cell types show daily rhythms in gene expression driven by a circadian pacemaker. For example, cultured astrocytes display circadian rhythms in Period1 and Period2 expression. It is not known, however, how or which intercellular factors synchronize and sustain rhythmicity in astrocytes. Because astrocytes are highly sensitive to vasoactive intestinal polypeptide (VIP), a neuropeptide released by neurons and important for the coordination of daily cycling, the authors hypothesized that VIP entrains circadian rhythms in astrocytes. They used astrocyte cultures derived from knock-in mice containing a bioluminescent reporter of PERIOD2 (PER2) protein, to assess the effects of VIP on the rhythmic properties of astrocytes. VIP induced a dose-dependent increase in the peak-to-trough amplitude of the ensemble rhythms of PER2 expression with maximal effects near 100 nM VIP and threshold values between 0.1 and 1 nM. VIP also induced dose- and phase-dependent shifts in PER2 rhythms and daily VIP administration entrained bioluminescence rhythms of astrocytes to a predicted phase angle. This is the first demonstration that a neuropeptide can entrain glial cells to a phase predicted by a phase-response curve. The authors conclude that VIP potently entrains astrocytes in vitro and is a candidate for coordinating daily rhythms among glia in the brain. PMID:19346450

  18. Vasoactive intestinal polypeptide entrains circadian rhythms in astrocytes

    PubMed Central

    Marpegan, Luciano; Krall, Thomas J.; Herzog, Erik D.

    2009-01-01

    Many mammalian cell types show daily rhythms in gene expression driven by a circadian pacemaker. For example, cultured astrocytes display circadian rhythms in Period1 and Period2 expression. It is not known, however, how or which intercellular factors synchronize and sustain rhythmicity in astrocytes. Because astrocytes are highly sensitive to vasoactive intestinal polypeptide (VIP), a neuropeptide released by neurons and important for the coordination of daily cycling, we hypothesized that VIP entrains circadian rhythms in astrocytes. We used astrocyte cultures derived from knock-in mice containing a bioluminescent reporter of PERIOD2 (PER2) protein, to assess the effects of VIP on the rhythmic properties of astrocytes. VIP induced a dose-dependent increase in the peak-to-trough amplitude of the ensemble rhythms of PER2 expression with maximal effects near 100nM VIP and threshold values between 0.1 and 1 nM. VIP also induced dose- and phase-dependent shifts in PER2 rhythms and daily VIP administration entrained bioluminescence rhythms of astrocytes to a predicted phase angle. This is the first demonstration that a neuropeptide can entrain glial cells to a phase predicted by a phase response curve. We conclude that VIP potently entrains astrocytes in vitro and is a candidate for coordinating daily rhythms among glia in the brain. PMID:19346450

  19. Neural Networks for Beat Perception in Musical Rhythm

    PubMed Central

    Large, Edward W.; Herrera, Jorge A.; Velasco, Marc J.

    2015-01-01

    Entrainment of cortical rhythms to acoustic rhythms has been hypothesized to be the neural correlate of pulse and meter perception in music. Dynamic attending theory first proposed synchronization of endogenous perceptual rhythms nearly 40 years ago, but only recently has the pivotal role of neural synchrony been demonstrated. Significant progress has since been made in understanding the role of neural oscillations and the neural structures that support synchronized responses to musical rhythm. Synchronized neural activity has been observed in auditory and motor networks, and has been linked with attentional allocation and movement coordination. Here we describe a neurodynamic model that shows how self-organization of oscillations in interacting sensory and motor networks could be responsible for the formation of the pulse percept in complex rhythms. In a pulse synchronization study, we test the model's key prediction that pulse can be perceived at a frequency for which no spectral energy is present in the amplitude envelope of the acoustic rhythm. The result shows that participants perceive the pulse at the theoretically predicted frequency. This model is one of the few consistent with neurophysiological evidence on the role of neural oscillation, and it explains a phenomenon that other computational models fail to explain. Because it is based on a canonical model, the predictions hold for an entire family of dynamical systems, not only a specific one. Thus, this model provides a theoretical link between oscillatory neurodynamics and the induction of pulse and meter in musical rhythm. PMID:26635549

  20. Heterogeneity induces rhythms of weakly coupled circadian neurons.

    PubMed

    Gu, Changgui; Liang, Xiaoming; Yang, Huijie; Rohling, Jos H T

    2016-01-01

    The main clock located in the suprachiasmatic nucleus (SCN) regulates circadian rhythms in mammals. The SCN is composed of approximately twenty thousand heterogeneous self-oscillating neurons, that have intrinsic periods varying from 22 h to 28 h. They are coupled through neurotransmitters and neuropeptides to form a network and output a uniform periodic rhythm. Previous studies found that the heterogeneity of the neurons leads to attenuation of the circadian rhythm with strong cellular coupling. In the present study, we investigate the heterogeneity of the neurons and of the network in the condition of constant darkness. Interestingly, we found that the heterogeneity of weakly coupled neurons enables them to oscillate and strengthen the circadian rhythm. In addition, we found that the period of the SCN network increases with the increase of the degree of heterogeneity. As the network heterogeneity does not change the dynamics of the rhythm, our study shows that the heterogeneity of the neurons is vitally important for rhythm generation in weakly coupled systems, such as the SCN, and it provides a new method to strengthen the circadian rhythm, as well as an alternative explanation for differences in free running periods between species in the absence of the daily cycle. PMID:26898574

  1. Heterogeneity induces rhythms of weakly coupled circadian neurons

    PubMed Central

    Gu, Changgui; Liang, Xiaoming; Yang, Huijie; Rohling, Jos H. T.

    2016-01-01

    The main clock located in the suprachiasmatic nucleus (SCN) regulates circadian rhythms in mammals. The SCN is composed of approximately twenty thousand heterogeneous self-oscillating neurons, that have intrinsic periods varying from 22 h to 28 h. They are coupled through neurotransmitters and neuropeptides to form a network and output a uniform periodic rhythm. Previous studies found that the heterogeneity of the neurons leads to attenuation of the circadian rhythm with strong cellular coupling. In the present study, we investigate the heterogeneity of the neurons and of the network in the condition of constant darkness. Interestingly, we found that the heterogeneity of weakly coupled neurons enables them to oscillate and strengthen the circadian rhythm. In addition, we found that the period of the SCN network increases with the increase of the degree of heterogeneity. As the network heterogeneity does not change the dynamics of the rhythm, our study shows that the heterogeneity of the neurons is vitally important for rhythm generation in weakly coupled systems, such as the SCN, and it provides a new method to strengthen the circadian rhythm, as well as an alternative explanation for differences in free running periods between species in the absence of the daily cycle. PMID:26898574

  2. Neural Responses to Complex Auditory Rhythms: The Role of Attending

    PubMed Central

    Chapin, Heather L.; Zanto, Theodore; Jantzen, Kelly J.; Kelso, Scott J. A.; Steinberg, Fred; Large, Edward W.

    2010-01-01

    The aim of this study was to explore the role of attention in pulse and meter perception using complex rhythms. We used a selective attention paradigm in which participants attended to either a complex auditory rhythm or a visually presented word list. Performance on a reproduction task was used to gauge whether participants were attending to the appropriate stimulus. We hypothesized that attention to complex rhythms – which contain no energy at the pulse frequency – would lead to activations in motor areas involved in pulse perception. Moreover, because multiple repetitions of a complex rhythm are needed to perceive a pulse, activations in pulse-related areas would be seen only after sufficient time had elapsed for pulse perception to develop. Selective attention was also expected to modulate activity in sensory areas specific to the modality. We found that selective attention to rhythms led to increased BOLD responses in basal ganglia, and basal ganglia activity was observed only after the rhythms had cycled enough times for a stable pulse percept to develop. These observations suggest that attention is needed to recruit motor activations associated with the perception of pulse in complex rhythms. Moreover, attention to the auditory stimulus enhanced activity in an attentional sensory network including primary auditory cortex, insula, anterior cingulate, and prefrontal cortex, and suppressed activity in sensory areas associated with attending to the visual stimulus. PMID:21833279

  3. Neural Networks for Beat Perception in Musical Rhythm.

    PubMed

    Large, Edward W; Herrera, Jorge A; Velasco, Marc J

    2015-01-01

    Entrainment of cortical rhythms to acoustic rhythms has been hypothesized to be the neural correlate of pulse and meter perception in music. Dynamic attending theory first proposed synchronization of endogenous perceptual rhythms nearly 40 years ago, but only recently has the pivotal role of neural synchrony been demonstrated. Significant progress has since been made in understanding the role of neural oscillations and the neural structures that support synchronized responses to musical rhythm. Synchronized neural activity has been observed in auditory and motor networks, and has been linked with attentional allocation and movement coordination. Here we describe a neurodynamic model that shows how self-organization of oscillations in interacting sensory and motor networks could be responsible for the formation of the pulse percept in complex rhythms. In a pulse synchronization study, we test the model's key prediction that pulse can be perceived at a frequency for which no spectral energy is present in the amplitude envelope of the acoustic rhythm. The result shows that participants perceive the pulse at the theoretically predicted frequency. This model is one of the few consistent with neurophysiological evidence on the role of neural oscillation, and it explains a phenomenon that other computational models fail to explain. Because it is based on a canonical model, the predictions hold for an entire family of dynamical systems, not only a specific one. Thus, this model provides a theoretical link between oscillatory neurodynamics and the induction of pulse and meter in musical rhythm. PMID:26635549

  4. Endogenous thermoregulatory rhythms of squirrel monkeys in thermoneutrality and cold

    NASA Technical Reports Server (NTRS)

    Robinson, E. L.; Fuller, C. A.

    1999-01-01

    Whole body heat production (HP) and heat loss (HL) were examined to determine if the free-running circadian rhythm in body temperature (Tb) results from coordinated changes in HP and HL rhythms in thermoneutrality (27 degrees C) as well as mild cold (17 degrees C). Squirrel monkey metabolism (n = 6) was monitored by both indirect and direct calorimetry, with telemetered measurement of Tb and activity. Feeding was also measured. Rhythms of HP, HL, and conductance were tightly coupled with the circadian Tb rhythm at both ambient temperatures (TA). At 17 degrees C, increased HP compensated for higher HL at all phases of the Tb rhythm, resulting in only minor changes to Tb. Parallel compensatory changes of HP and HL were seen at all rhythm phases at both TA. Similar time courses of Tb, HP, and HL in their respective rhythms and the relative stability of Tb during both active and rest periods suggest action of the circadian timing system on Tb set point.

  5. Inverse Correlation between Heart Rate Variability and Heart Rate Demonstrated by Linear and Nonlinear Analysis.

    PubMed

    Kazmi, Syed Zaki Hassan; Zhang, Henggui; Aziz, Wajid; Monfredi, Oliver; Abbas, Syed Ali; Shah, Saeed Arif; Kazmi, Syeda Sobia Hassan; Butt, Wasi Haider

    2016-01-01

    The dynamical fluctuations in the rhythms of biological systems provide valuable information about the underlying functioning of these systems. During the past few decades analysis of cardiac function based on the heart rate variability (HRV; variation in R wave to R wave intervals) has attracted great attention, resulting in more than 17000-publications (PubMed list). However, it is still controversial about the underling mechanisms of HRV. In this study, we performed both linear (time domain and frequency domain) and nonlinear analysis of HRV data acquired from humans and animals to identify the relationship between HRV and heart rate (HR). The HRV data consists of the following groups: (a) human normal sinus rhythm (n = 72); (b) human congestive heart failure (n = 44); (c) rabbit sinoatrial node cells (SANC; n = 67); (d) conscious rat (n = 11). In both human and animal data at variant pathological conditions, both linear and nonlinear analysis techniques showed an inverse correlation between HRV and HR, supporting the concept that HRV is dependent on HR, and therefore, HRV cannot be used in an ordinary manner to analyse autonomic nerve activity of a heart. PMID:27336907

  6. Inverse Correlation between Heart Rate Variability and Heart Rate Demonstrated by Linear and Nonlinear Analysis

    PubMed Central

    Zhang, Henggui; Aziz, Wajid; Monfredi, Oliver; Abbas, Syed Ali; Shah, Saeed Arif; Kazmi, Syeda Sobia Hassan; Butt, Wasi Haider

    2016-01-01

    The dynamical fluctuations in the rhythms of biological systems provide valuable information about the underlying functioning of these systems. During the past few decades analysis of cardiac function based on the heart rate variability (HRV; variation in R wave to R wave intervals) has attracted great attention, resulting in more than 17000-publications (PubMed list). However, it is still controversial about the underling mechanisms of HRV. In this study, we performed both linear (time domain and frequency domain) and nonlinear analysis of HRV data acquired from humans and animals to identify the relationship between HRV and heart rate (HR). The HRV data consists of the following groups: (a) human normal sinus rhythm (n = 72); (b) human congestive heart failure (n = 44); (c) rabbit sinoatrial node cells (SANC; n = 67); (d) conscious rat (n = 11). In both human and animal data at variant pathological conditions, both linear and nonlinear analysis techniques showed an inverse correlation between HRV and HR, supporting the concept that HRV is dependent on HR, and therefore, HRV cannot be used in an ordinary manner to analyse autonomic nerve activity of a heart. PMID:27336907

  7. Modelling the heart as a communication system

    PubMed Central

    Ashikaga, Hiroshi; Aguilar-Rodríguez, José; Gorsky, Shai; Lusczek, Elizabeth; Marquitti, Flávia Maria Darcie; Thompson, Brian; Wu, Degang; Garland, Joshua

    2015-01-01

    Electrical communication between cardiomyocytes can be perturbed during arrhythmia, but these perturbations are not captured by conventional electrocardiographic metrics. We developed a theoretical framework to quantify electrical communication using information theory metrics in two-dimensional cell lattice models of cardiac excitation propagation. The time series generated by each cell was coarse-grained to 1 when excited or 0 when resting. The Shannon entropy for each cell was calculated from the time series during four clinically important heart rhythms: normal heartbeat, anatomical reentry, spiral reentry and multiple reentry. We also used mutual information to perform spatial profiling of communication during these cardiac arrhythmias. We found that information sharing between cells was spatially heterogeneous. In addition, cardiac arrhythmia significantly impacted information sharing within the heart. Entropy localized the path of the drifting core of spiral reentry, which could be an optimal target of therapeutic ablation. We conclude that information theory metrics can quantitatively assess electrical communication among cardiomyocytes. The traditional concept of the heart as a functional syncytium sharing electrical information cannot predict altered entropy and information sharing during complex arrhythmia. Information theory metrics may find clinical application in the identification of rhythm-specific treatments which are currently unmet by traditional electrocardiographic techniques. PMID:25740854

  8. Update on heart failure, heart transplant, congenital heart disease, and clinical cardiology.

    PubMed

    Almenar, Luis; Zunzunegui, José Luis; Barón, Gonzalo; Carrasco, José Ignacio; Gómez-Doblas, Juan José; Comín, Josep; Barrios, Vivencio; Subirana, M Teresa; Díaz-Molina, Beatriz

    2013-04-01

    In the year 2012, 3 scientific sections-heart failure and transplant, congenital heart disease, and clinical cardiology-are presented together in the same article. The most relevant development in the area of heart failure and transplantation is the 2012 publication of the European guidelines for heart failure. These describe new possibilities for some drugs (eplerenone and ivabradine); expand the criteria for resynchronization, ventricular assist, and peritoneal dialysis; and cover possibilities of percutaneous repair of the mitral valve (MitraClip(®)). The survival of children with hypoplastic left heart syndrome in congenital heart diseases has improved significantly. Instructions for percutaneous techniques and devices have been revised and modified for the treatment of atrial septal defects, ostium secundum, and ventricular septal defects. Hybrid procedures for addressing structural congenital heart defects have become more widespread. In the area of clinical cardiology studies have demonstrated that percutaneous prosthesis implantation has lower mortality than surgical implantation. Use of the CHA2DS2-VASc criteria and of new anticoagulants (dabigatran, rivaroxaban and apixaban) is also recommended. In addition, the development of new sequencing techniques has enabled the analysis of multiple genes. PMID:24775619

  9. 2013 update on congenital heart disease, clinical cardiology, heart failure, and heart transplant.

    PubMed

    Subirana, M Teresa; Barón-Esquivias, Gonzalo; Manito, Nicolás; Oliver, José M; Ripoll, Tomás; Lambert, Jose Luis; Zunzunegui, José L; Bover, Ramon; García-Pinilla, José Manuel

    2014-03-01

    This article presents the most relevant developments in 2013 in 3 key areas of cardiology: congenital heart disease, clinical cardiology, and heart failure and transplant. Within the area of congenital heart disease, we reviewed contributions related to sudden death in adult congenital heart disease, the importance of specific echocardiographic parameters in assessing the systemic right ventricle, problems in patients with repaired tetralogy of Fallot and indication for pulmonary valve replacement, and confirmation of the role of specific factors in the selection of candidates for Fontan surgery. The most recent publications in clinical cardiology include a study by a European working group on correct diagnostic work-up in cardiomyopathies, studies on the cost-effectiveness of percutaneous aortic valve implantation, a consensus document on the management of type B aortic dissection, and guidelines on aortic valve and ascending aortic disease. The most noteworthy developments in heart failure and transplantation include new American guidelines on heart failure, therapeutic advances in acute heart failure (serelaxin), the management of comorbidities such as iron deficiency, risk assessment using new biomarkers, and advances in ventricular assist devices. PMID:24774396

  10. Circadian rhythms in human performance and mood under constant conditions

    NASA Technical Reports Server (NTRS)

    Monk, T. H.; Buysse, D. J.; Reynolds, C. F. 3rd; Berga, S. L.; Jarrett, D. B.; Begley, A. E.; Kupfer, D. J.

    1997-01-01

    This study explored the relationship between circadian performance rhythms and rhythms in rectal temperature, plasma cortisol, plasma melatonin, subjective alertness and well-being. Seventeen healthy young adults were studied under 36 h of 'unmasking' conditions (constant wakeful bedrest, temporal isolation, homogenized 'meals') during which rectal temperatures were measured every minute, and plasma cortisol and plasma melatonin measured every 20 min. Hourly subjective ratings of global vigour (alertness) and affect (well-being) were obtained followed by one of two performance batteries. On odd-numbered hours performance (speed and accuracy) of serial search, verbal reasoning and manual dexterity tasks was assessed. On even-numbered hours, performance (% hits, response speed) was measured at a 25-30 min visual vigilance task. Performance of all tasks (except search accuracy) showed a significant time of day variation usually with a nocturnal trough close to the trough in rectal temperature. Performance rhythms appeared not to reliably differ with working memory load. Within subjects, predominantly positive correlations emerged between good performance and higher temperatures and better subjective alertness; predominantly negative correlations between good performance and higher plasma levels of cortisol and melatonin. Temperature and cortisol rhythms correlated with slightly more performance measures (5/7) than did melatonin rhythms (4/7). Global vigour correlated about as well with performance (5/7) as did temperature, and considerably better than global affect (1/7). In conclusion: (1) between-task heterogeneity in circadian performance rhythms appeared to be absent when the sleep/wake cycle was suspended; (2) temperature (positively), cortisol and melatonin (negatively) appeared equally good as circadian correlates of performance, and (3) subjective alertness correlated with performance rhythms as well as (but not better than) body temperature, suggesting that

  11. Complex Dynamics of the Cardiac Rhythms

    NASA Astrophysics Data System (ADS)

    Filippi, S.; Cherubini, C.

    Many biological systems which appear complex both in space and time and result still not understood, require new theoretical approaches for their nonlinear dynamics. In particular we focus here on the theoretical analysis of the underlying mechanisms of heart dynamics. This could clarify the (apparently) chaotic behavior of the normal heart-beat and especially the control of the bifurcations of dynamics arising in situ- ations of disease. The principal target is to find a possible clear distinction between normal and pathological regimes. A discussion of Complex Ginzburg-Landau equation can give useful hints to this aim.

  12. Circadian rhythms from multiple oscillators: lessons from diverse organisms.

    PubMed

    Bell-Pedersen, Deborah; Cassone, Vincent M; Earnest, David J; Golden, Susan S; Hardin, Paul E; Thomas, Terry L; Zoran, Mark J

    2005-07-01

    The organization of biological activities into daily cycles is universal in organisms as diverse as cyanobacteria, fungi, algae, plants, flies, birds and man. Comparisons of circadian clocks in unicellular and multicellular organisms using molecular genetics and genomics have provided new insights into the mechanisms and complexity of clock systems. Whereas unicellular organisms require stand-alone clocks that can generate 24-hour rhythms for diverse processes, organisms with differentiated tissues can partition clock function to generate and coordinate different rhythms. In both cases, the temporal coordination of a multi-oscillator system is essential for producing robust circadian rhythms of gene expression and biological activity. PMID:15951747

  13. Attraction and social coordination: mutual entrainment of vocal activity rhythms.

    PubMed

    McGarva, Andrew R; Warner, Rebecca M

    2003-05-01

    To investigate factors that affect the mutual entrainment of vocal activity rhythms, female general psychology students paired according to attitude similarity questionnaires engaged in 40-minute introductory conversations. Fourier analyses performed on speakers' on-off vocal activity demonstrated periodic oscillations in talkativeness. Although some dyads coordinated their vocal activity rhythms, speech accommodation was not predicted by attitude similarity or attraction and did not affect ratings of conversation quality. These rhythms of dialogue appear resistant to change, their behavioral momentum rooted perhaps in an underlying chronobiology. PMID:12845943

  14. Women and heart disease, the underrecognized burden: sex differences, biases, and unmet clinical and research challenges.

    PubMed

    Westerman, Stacy; Wenger, Nanette K

    2016-04-01

    For many years the significance of heart disease in women was vastly underappreciated, and women were significantly underrepresented in cardiovascular clinical research. We now know that cardiovascular disease is the leading cause of death for women. Women and men share many similarities in the pathophysiology and manifestations of heart disease. However, as research advances with the continued inclusion of more women, knowledge about gender differences between the female and male heart, both on a physiological and pathophysiological basis, grows. These differences can be found in all domains of cardiovascular health and disease, including heart rhythm, heart failure, coronary disease and valvular disease. Further understanding of gender differences in the heart is crucial for advancing our ability to maintain a healthy population and identify and treat heart disease in both women and men. Specific examples within the spectrum of heart disease will be discussed in this review paper, and areas for further research will be proposed. PMID:26957643

  15. Atrial Fibrillation, Congestive Heart Failure, and the Middle Cerebral Artery.

    PubMed

    Ameriso, S F; Sager, P; Fisher, M

    1992-10-01

    Atrial fibrillation and congestive heart failure are risk factors for ischemic stroke usually attributed to cardiac embolism. To define potential alternative mechanisms, patients with atrial fibrillation and congestive heart failure were investigated by transcranial Doppler. Middle cerebral artery (MCA) blood flow velocities were analyzed in neurologically asymptomatic patients with nonvalvular (n = 10) and valvular (n = 13) atrial fibrillation, patients in normal sinus rhythm with congestive heart failure (n = 13), and control subjects (n = 11). Compared to patients in sinus rhythm with congestive heart failure and to control subjects, patients in both atrial fibrillation groups had significantly greater beat-to-beat variation in peak, mean, and diastolic velocities and in pulsatility index. Peak, mean, and diastolic MCA velocities in patients with atrial fibrillation and those with congestive heart failure were significantly less than those in control subjects. Patients with nonvalvular atrial fibrillation had a higher pulsatility index compared to each of the other three groups. These findings demonstrate substantial nonemboligenic alterations of the intracranial circulation associated with atrial fibrillation and congestive heart failure, and also provide an intracranial hemodynamic profile that may distinguish valvular from nonvalvular atrial fibrillation. PMID:27309151

  16. European Mistletoe

    MedlinePlus

    ... gov Key References American mistletoe. Natural Medicines Comprehensive Database Web site. Accessed at www.naturaldatabase.com on July 7, 2009. European mistletoe. Natural Medicines Comprehensive Database Web site. Accessed at www.naturaldatabase.com on July ...

  17. European Community.

    PubMed

    1987-05-01

    The European Community was established in 1951 to reconcile France and Germany after World War II and to make possible the eventual federation of Europe. By 1986, there were 12 member countries: France, Italy, Belgium, the Federal Republic of Germany, Luxembourg, the Netherlands, Denmark, Ireland, the United Kingdom, Greece, Spain, and Portugal. Principal areas of concern are internal and external trade, agriculture, monetary coordination, fisheries, common industrial and commercial policies, assistance, science and research, and common social and regional policies. The European Community has a budget of US$34.035 billion/year, funded by customs duties and 1.4% of each member's value-added tax. The treaties establishing the European Community call for members to form a common market, a common customs tariff, and common agricultural, transport, economic, and nuclear policies. Major European Community institutions include the Commission, Council of Ministers, European Parliament, Court of Justice, and Economic and Social Committee. The Community is the world's largest trading unit, accounting for 15% of world trade. The 2 main goals of the Community's industrial policy are to create an open internal market and to promote technological innovation in order to improve international competitiveness. The European Community aims to contribute to the economic and social development of Third World countries as well. PMID:12177941

  18. Menstrual changes in sleep, rectal temperature and melatonin rhythms in a subject with premenstrual syndrome.

    PubMed

    Shinohara, K; Uchiyama, M; Okawa, M; Saito, K; Kawaguchi, M; Funabashi, T; Kimura, F

    2000-03-10

    We studied a sighted woman with premenstrual syndrome who showed menstrual changes in circadian rhythms. She showed alternative phase shifts in the sleep rhythm in the menstrual cycle: progressive phase advances in the follicular phase and phase delays in the luteal phase. Rectal temperature rhythm also showed similar menstrual changes, but the phase advance and delay started a few days earlier than changes in sleep-wake rhythm so that the two rhythms were dissociated around ovulation and menstruation. These results suggest that her circadian rhythms in sleep and temperature are under the control of ovarian steroid hormones and that these two rhythms have different sensitivity to the hormones. PMID:10704767

  19. Speech rhythm sensitivity and musical aptitude: ERPs and individual differences.

    PubMed

    Magne, Cyrille; Jordan, Deanna K; Gordon, Reyna L

    2016-02-01

    This study investigated the electrophysiological markers of rhythmic expectancy during speech perception. In addition, given the large literature showing overlaps between cognitive and neural resources recruited for language and music, we considered a relation between musical aptitude and individual differences in speech rhythm sensitivity. Twenty adults were administered a standardized assessment of musical aptitude, and EEG was recorded as participants listened to sequences of four bisyllabic words for which the stress pattern of the final word either matched or mismatched the stress pattern of the preceding words. Words with unexpected stress patterns elicited an increased fronto-central mid-latency negativity. In addition, rhythm aptitude significantly correlated with the size of the negative effect elicited by unexpected iambic words, the least common type of stress pattern in English. The present results suggest shared neurocognitive resources for speech rhythm and musical rhythm. PMID:26828758

  20. Rhythm: A Psycho-Philosophical Perspective on Black Behavior.

    ERIC Educational Resources Information Center

    Toldson, Ivory L.; Pasteur, Alfred B.

    1982-01-01

    Discusses rhythm as a fundamental element in human behavior. Suggests that the unity of cognitive, affective, and psychomotor functioning, most vividly seen in Black expressive forms, must be studied to more fully understand Black behavior and learning styles. (RC)

  1. Social Rhythm Therapies for Mood Disorders: an Update.

    PubMed

    Haynes, Patricia L; Gengler, Devan; Kelly, Monica

    2016-08-01

    Social rhythms are patterns of habitual daily behaviors that may impact the timing of the circadian system directly or indirectly through light exposure. According to the social rhythm hypothesis of depression, depressed individuals possess a vulnerability in the circadian timing system that inhibits natural recovery after disrupting life events. Social rhythm therapies (SRTs) support the implementation of regular, daily patterns of activity in order to facilitate recovery of circadian biological processes and also to improve mood. The majority of SRT research has examined interpersonal and social rhythm therapy (IPSRT) for bipolar disorder. Recent studies have examined IPSRT in inpatient settings, using alternative modes of delivery (group, combined individual and group, internet-based applications) and with brief timeframes. New forms of SRTs are developing that target mood in individuals who have experienced specific types of stressful life events. This manuscript reviews the theoretical and biological bases of SRTs and current literature on SRT outcomes. PMID:27338753

  2. Preliminary characterization of persisting circadian rhythms during space flight

    NASA Technical Reports Server (NTRS)

    Sultzman, F. M.

    1984-01-01

    In order to evaluate the function of the circadian timing system in space, the circadian rhythm of conidiation of the fungus Neurospora crassa was monitored in constant darkness on the STS 9 flight of the Space Shuttle Columbia. During the first 7 days of spaceflight many tubes showed a marked reduction in the apparent amplitude of the conidiation rhythm, and some cultures appeared arrhythmic. There was more variability in the growth rate and circadian rhythms of individual cultures in space than is usually seen on earth. The results of this experiment indicate that while the circadian rhythm of Neurospora conidiation can persist outside of the earth's environment, either the timekeeping process or its expression is altered in space.

  3. Age, circadian rhythms, and sleep loss in flight crews

    NASA Technical Reports Server (NTRS)

    Gander, Philippa H.; Nguyen, DE; Rosekind, Mark R.; Connell, Linda J.

    1993-01-01

    Age-related changes in trip-induced sleep loss, personality, and the preduty temperature rhythm were analyzed in crews from various flight operations. Eveningness decreased with age. The minimum of the baseline temperature rhythm occurred earlier with age. The amplitude of the baseline temperature rhythm declined with age. Average daily percentage sleep loss during trips increased with age. Among crewmembers flying longhaul flight operations, subjects aged 50-60 averaged 3.5 times more sleep loss per day than subjects aged 20-30. These studies support previous findings that evening types and subjects with later peaking temperature rhythms adapt better to shift work and time zone changes. Age and circadian type may be important considerations for duty schedules and fatigue countermeasures.

  4. Language familiarity, expectation, and novice musical rhythm production.

    PubMed

    Neuhoff, John G; Lidji, Pascale

    2014-12-01

    The music of expert musicians reflects the speech rhythm of their native language. Here, we examine this effect in amateur and novice musicians. English- and French-speaking participants were both instructed to produce simple "English" and "French" tunes using only two keys on a keyboard. All participants later rated the rhythmic variability of English and French speech samples. The rhythmic variability of the "English" and "French" tunes that were produced reflected the perceived rhythmic variability in English and French speech samples. Yet, the pattern was different for English and French participants and did not correspond to the actual measured speech rhythm variability of the speech samples. Surprise recognition tests two weeks later confirmed that the music-speech relationship remained over time. The results show that the relationship between music and speech rhythm is more widespread than previously thought and that musical rhythm production by amateurs and novices is concordant with their rhythmic expectations in the perception of speech. PMID:25536848

  5. A hypothesis: autonomic rhythms are reflected in growth lines of teeth in humans and extinct archosaurs.

    PubMed

    Appenzeller, O; Gunga, H-C; Qualls, C; Furlan, R; Porta, A; Lucas, S G; Heckert, A B; Kirsch, K; Costa-Junqueira, M A; Guillén, S E; Sander, M; Schneider, T; Blottner, B

    2005-02-01

    A major determinant of tooth architecture is the arrangement of lines in dentin and in the enamel following the contour of the surface. Since the original description of these lines in the 19th century, they have been attributed to recurring events during tooth development. They have also attracted the attention of dental scientists and anthropologists; however, to date, studies of these structures have been largely theoretical and microscopic. We show here that the statistical properties of the spacing between the lines are similar in teeth from both ancient and modern humans and from extinct archosaurs, reptiles that lived tens or hundreds of millions of years ago-they also resemble heart rate variability of living humans. We propose that the deposition of these recurring structures is controlled by the autonomic nervous system. This control accounts for their regularity and recurrent nature and implies that the lines are an expression of a biologic rhythm which has been conserved throughout evolution. Details of the rhythms give clues to life styles in ancient civilizations and to the physiology of extinct archosaurs. PMID:15664564

  6. Methods to Record Circadian Rhythm Wheel Running Activity in Mice

    PubMed Central

    Siepka, Sandra M.; Takahashi, Joseph S.

    2013-01-01

    Forward genetic approaches (phenotype to gene) are powerful methods to identify mouse circadian clock components. The success of these approaches, however, is highly dependent on the quality of the phenotype— specifically, the ability to measure circadian rhythms in individual mice. This article outlines the factors necessary to measure mouse circadian rhythms, including choice of mouse strain, facilities and equipment design and construction, experimental design, high-throughput methods, and finally methods for data analysis. PMID:15817291

  7. Looking for inspiration: new perspectives on respiratory rhythm

    PubMed Central

    Feldman, Jack L.; Del Negro, Christopher A.

    2010-01-01

    Recent experiments in vivo and in vitro have advanced our understanding of the sites and mechanisms involved in mammalian respiratory rhythm generation. Here we evaluate and interpret the new evidence for two separate brainstem respiratory oscillators and for the essential role of emergent network properties in rhythm generation. Lesion studies suggest that respiratory cell death might explain morbidity and mortality associated with neurodegenerative disorders and ageing. PMID:16495944

  8. Circadian Rhythms in Stomatal Responsiveness to Red and Blue Light.

    PubMed Central

    Gorton, H. L.; Williams, W. E.; Assmann, S. M.

    1993-01-01

    Stomata of many plants have circadian rhythms in responsiveness to environmental cues as well as circadian rhythms in aperture. Stomatal responses to red light and blue light are mediated by photosynthetic photoreceptors; responses to blue light are additionally controlled by a specific blue-light photoreceptor. This paper describes circadian rhythmic aspects of stomatal responsiveness to red and blue light in Vicia faba. Plants were exposed to a repeated light:dark regime of 1.5:2.5 h for a total of 48 h, and because the plants could not entrain to this short light:dark cycle, circadian rhythms were able to "free run" as if in continuous light. The rhythm in the stomatal conductance established during the 1.5-h light periods was caused both by a rhythm in sensitivity to light and by a rhythm in the stomatal conductance established during the preceding 2.5-h dark periods. Both rhythms peaked during the middle of the subjective day. Although the stomatal response to blue light is greater than the response to red light at all times of day, there was no discernible difference in period, phase, or amplitude of the rhythm in sensitivity to the two light qualities. We observed no circadian rhythmicity in net carbon assimilation with the 1.5:2.5 h light regime for either red or blue light. In continuous white light, small rhythmic changes in photosynthetic assimilation were observed, but at relatively high light levels, and these appeared to be attributable largely to changes in internal CO2 availability governed by stomatal conductance. PMID:12231947

  9. Assessment of Cardiac Rate and Rhythm in Fetuses with Arrhythmia via Maternal Abdominal Fetal Electrocardiography

    PubMed Central

    Narayan, Hari K.; Vignola, Emilia F.; Fifer, William P.; Williams, Ismee A.

    2015-01-01

    Objective This study aims to report our experience using the Monica AN24 (Monica Healthcare Ltd., Nottingham, United Kingdom), a maternal transabdominal fetal electrocardiographic monitor, in a case series of fetuses with arrhythmias. Study Design We recorded fetal electrocardiograms (fECGs) on subjects with fetal arrhythmias diagnosed by fetal echocardiogram. Fetal heart rate and rhythm were determined via manual fECG analysis. Results Overall, 20 fECGs were recorded from a pool of 13 subjects. Fetal heart rate acquisition was determined to be high, medium, and poor quality in 10, 3, and 7 tracings, respectively. High-quality tracings were obtained in 9 of 11 subjects with gestational age < 26 or > 34 weeks. P waves were detectable in five tracings. Conclusion In subjects < 26 or > 34 weeks' gestational age, there was reasonable success in fetal heart rate acquisition. Further study is warranted to determine the potential role of this device in the monitoring of subjects with fetal arrhythmias. PMID:26495180

  10. Circannual rhythms of physical fitness and tolerance of hypoxic hypoxia.

    PubMed

    Kwarecki, K; Golec, L; Kłossowski, M; Zuzewicz, K

    1981-01-01

    Presence of a circannual rhythm of physical fitness and tolerance of hypoxia was demonstrated. The rhythm of physical fitness had two peaks, in April and September. Using cosinor analysis the acrophase of the circannual rhythm was found to be on Aug. 10 with a 95% confidence limit (May 30-October 16), and the amplitude of the rhythm was 1.6 ml O2/kg/min with a 95% confidence limit (0.22-2.96 ml/kg/min). The circannual rhythm of hypoxia tolerance showed a similar pattern of changes. The maximum value of this rhythm was observed also in April and in autumn, its acrophase was calculated to occur on Aug. 26 with a 95% confidence limit (May 10-October 2), and its amplitude was 33.4 sec with a 95% confidence limit (10.4-56.4 sec.). An analysis of the results of physical fitness tests carried out in training camps confirmed these circannual fluctuations of physical fitness. PMID:7348519

  11. Dynamical Analysis of bantam-Regulated Drosophila Circadian Rhythm Model

    NASA Astrophysics Data System (ADS)

    Li, Ying; Liu, Zengrong

    MicroRNAs (miRNAs) interact with 3‧untranslated region (UTR) elements of target genes to regulate mRNA stability or translation, and play a crucial role in regulating many different biological processes. bantam, a conserved miRNA, is involved in several functions, such as regulating Drosophila growth and circadian rhythm. Recently, it has been discovered that bantam plays a crucial role in the core circadian pacemaker. In this paper, based on experimental observations, a detailed dynamical model of bantam-regulated circadian clock system is developed to show the post-transcriptional behaviors in the modulation of Drosophila circadian rhythm, in which the regulation of bantam is incorporated into a classical model. The dynamical behaviors of the model are consistent with the experimental observations, which shows that bantam is an important regulator of Drosophila circadian rhythm. The sensitivity analysis of parameters demonstrates that with the regulation of bantam the system is more sensitive to perturbations, indicating that bantam regulation makes it easier for the organism to modulate its period against the environmental perturbations. The effectiveness in rescuing locomotor activity rhythms of mutated flies shows that bantam is necessary for strong and sustained rhythms. In addition, the biological mechanisms of bantam regulation are analyzed, which may help us more clearly understand Drosophila circadian rhythm regulated by other miRNAs.

  12. Rhythm perception, production, and synchronization during the perinatal period

    PubMed Central

    Provasi, Joëlle; Anderson, David I.; Barbu-Roth, Marianne

    2014-01-01

    Sensori-motor synchronization (SMS) is the coordination of rhythmic movement with an external rhythm. It plays a central role in motor, cognitive, and social behavior. SMS is commonly studied in adults and in children from four years of age onward. Prior to this age, the ability has rarely been investigated due to a lack of available methods. The present paper reviews what is known about SMS in young children, infants, newborns, and fetuses. The review highlights fetal and infant perception of rhythm and cross modal perception of rhythm, fetal, and infant production of rhythm and cross modal production of rhythm, and the contexts in which production of rhythm can be observed in infants. A primary question is whether infants, even newborns, can modify their spontaneous rhythmical motor behavior in response to external rhythmical stimulation. Spontaneous sucking, crying, and leg movements have been studied in the presence or absence of rhythmical auditory stimulation. Findings suggest that the interaction between movement and sound is present at birth and that SMS can be observed in special conditions and within a narrow range of tempi, particularly near the infant’s own spontaneous motor tempo. The discussion centers on the fundamental role of SMS in interaction and communication at the beginning of life. PMID:25278929

  13. Circadian rhythm of alpha-amylase in rat parotid gland.

    PubMed

    Bellavía, S L; Sanz, E G; Chiarenza, A P; Sereno, R; Vermouth, N T

    1990-01-01

    The circadian rhythm of alpha-amylase, E.C. 3.2.1.1. (alpha-1,4-glucan-4-glucanohydrolase) in parotid gland of 25 day old rats was studied under different experimental conditions (fast, reversed photoperiod, constant light or darkness and treatment with reserpine and alpha-methyl-p-tyrosine). The rhythm of rats fasted or exposed for 7 days to constant darkness did not change. There were modifications in the rhythm of rats submitted to a reversed photoperiod and it disappeared in animals submitted to constant light or darkness for 15 days or treated with reserpine or alpha-methyl-p-tyrosine. The rhythm persisted, with minor changes in the acrophase, in parotids of rats kept during their gestation and post-natal life in constant light or darkness. Results suggest that the circadian rhythm of alpha-amylase in parotid gland of young rats is endogenous, synchronized by the photoperiod, under autonomous nervous system control and maternal coordination. This model appears to be useful in the study of sympathetic nervous system control of target organs and circadian rhythms in general. PMID:2076161

  14. The phonetic rhythm/syntax headedness connection: Evidence from Tagalog

    NASA Astrophysics Data System (ADS)

    Bird, Sonya; Fais, Laurel; Werker, Janet

    2005-04-01

    Ramus, Nespor, and Mehler [Cognition (1999)] show that the rhythm of a language (broadly: stress- versus syllable- versus mora-timing) results from the proportion of vocalic material in an utterance (%V) and the standard deviation of consonantal intervals (delta-C). Based on 14 languages, Shukla, Nespor, and Mehler [submitted] further argue that rhythm is correlated with syntactic headedness: low %V is correlated with head-first languages (e.g., English); high %V is correlated with head-final languages (e.g., Japanese). Together, these proposals have important implications for language acquisition: infants can discriminate across rhythm classes [Nazzi, Bertoncini, and Mehler, J. Exp. Psych: Human Perception and Performance (1998)]. If rhythm, as defined by %V and delta-C, can predict headedness, then infants can potentially use rhythm information to bootstrap into their languages syntactic structure. This paper reports on a study analyzing rhythm in a language not yet considered: Tagalog. Results support the Shukla et al. proposal in an interesting way: based on its %V and delta-C, Tagalog falls between head-first and head-last languages, slighty closer to the head-first group. This placement correlates well with the fact that, although Tagalog is said to be primarily head-first syntactically, head-last phrases are permitted and common in the language.

  15. Neural mechanisms of rhythm perception: current findings and future perspectives.

    PubMed

    Grahn, Jessica A

    2012-10-01

    Perception of temporal patterns is fundamental to normal hearing, speech, motor control, and music. Certain types of pattern understanding are unique to humans, such as musical rhythm. Although human responses to musical rhythm are universal, there is much we do not understand about how rhythm is processed in the brain. Here, I consider findings from research into basic timing mechanisms and models through to the neuroscience of rhythm and meter. A network of neural areas, including motor regions, is regularly implicated in basic timing as well as processing of musical rhythm. However, fractionating the specific roles of individual areas in this network has remained a challenge. Distinctions in activity patterns appear between "automatic" and "cognitively controlled" timing processes, but the perception of musical rhythm requires features of both automatic and controlled processes. In addition, many experimental manipulations rely on participants directing their attention toward or away from certain stimulus features, and measuring corresponding differences in neural activity. Many temporal features, however, are implicitly processed whether attended to or not, making it difficult to create controlled baseline conditions for experimental comparisons. The variety of stimuli, paradigms, and definitions can further complicate comparisons across domains or methodologies. Despite these challenges, the high level of interest and multitude of methodological approaches from different cognitive domains (including music, language, and motor learning) have yielded new insights and hold promise for future progress. PMID:22811317

  16. Biological rhythms as organization and information.

    PubMed

    Lloyd, D; Rossi, E L

    1993-11-01

    While it is generally acknowledged that modern science began with the quantification of time in the measurement of linear physical processes in space by Galileo and Newton, the biological sciences have only recently developed appropriate experimental and mathematical methods for the description of living systems in terms of processes of non-linear, recursive dynamics. We now recognize that living organisms have patterns of exquisitely timed processes that are as intricate as their spatial structure and organization. Self-similarities of life processes in time and space have evolved to generate an ensemble of oscillators within which analogous functions may be discerned on many different time scales. The increasing complexity of periodic relationships on and between the many levels of biological organization are uncovered by current research. Recent efforts to reformulate the foundation of physics from the quantum to the cosmological level by using the concept of information as the common denominator integrating time, structure and energy remind us of an apparently analogous suggestion in the chronobiological literature which also describes the periodic dynamics of living systems as information processing. In this paper we review the periodic processes of living systems on all levels from the molecular, genetic and cellular to the neuroendocrinological, behavioural and social domains. Biological rhythms may be conceptualized as the evolution of ever more complex dynamics of information transduction that optimize the temporal integrity, development, and survival of the organism. PMID:8130327

  17. Synchrony in silicon: the gamma rhythm.

    PubMed

    Arthur, John V; Boahen, Kwabena A

    2007-11-01

    In this paper, we present a network of silicon interneurons that synchronize in the gamma frequency range (20-80 Hz). The gamma rhythm strongly influences neuronal spike timing within many brain regions, potentially playing a crucial role in computation. Yet it has largely been ignored in neuromorphic systems, which use mixed analog and digital circuits to model neurobiology in silicon. Our neurons synchronize by using shunting inhibition (conductance based) with a synaptic rise time. Synaptic rise time promotes synchrony by delaying the effect of inhibition, providing an opportune period for interneurons to spike together. Shunting inhibition, through its voltage dependence, inhibits interneurons that spike out of phase more strongly (delaying the spike further), pushing them into phase (in the next cycle). We characterize the interneuron, which consists of soma (cell body) and synapse circuits, fabricated in a 0.25-microm complementary metal-oxide-semiconductor (CMOS). Further, we show that synchronized interneurons (population of 256) spike with a period that is proportional to the synaptic rise time. We use these interneurons to entrain model excitatory principal neurons and to implement a form of object binding. PMID:18051195

  18. Music and speech prosody: a common rhythm

    PubMed Central

    Hausen, Maija; Torppa, Ritva; Salmela, Viljami R.; Vainio, Martti; Särkämö, Teppo

    2013-01-01

    Disorders of music and speech perception, known as amusia and aphasia, have traditionally been regarded as dissociated deficits based on studies of brain damaged patients. This has been taken as evidence that music and speech are perceived by largely separate and independent networks in the brain. However, recent studies of congenital amusia have broadened this view by showing that the deficit is associated with problems in perceiving speech prosody, especially intonation and emotional prosody. In the present study the association between the perception of music and speech prosody was investigated with healthy Finnish adults (n = 61) using an on-line music perception test including the Scale subtest of Montreal Battery of Evaluation of Amusia (MBEA) and Off-Beat and Out-of-key tasks as well as a prosodic verbal task that measures the perception of word stress. Regression analyses showed that there was a clear association between prosody perception and music perception, especially in the domain of rhythm perception. This association was evident after controlling for music education, age, pitch perception, visuospatial perception, and working memory. Pitch perception was significantly associated with music perception but not with prosody perception. The association between music perception and visuospatial perception (measured using analogous tasks) was less clear. Overall, the pattern of results indicates that there is a robust link between music and speech perception and that this link can be mediated by rhythmic cues (time and stress). PMID:24032022

  19. Music and speech prosody: a common rhythm.

    PubMed

    Hausen, Maija; Torppa, Ritva; Salmela, Viljami R; Vainio, Martti; Särkämö, Teppo

    2013-01-01

    Disorders of music and speech perception, known as amusia and aphasia, have traditionally been regarded as dissociated deficits based on studies of brain damaged patients. This has been taken as evidence that music and speech are perceived by largely separate and independent networks in the brain. However, recent studies of congenital amusia have broadened this view by showing that the deficit is associated with problems in perceiving speech prosody, especially intonation and emotional prosody. In the present study the association between the perception of music and speech prosody was investigated with healthy Finnish adults (n = 61) using an on-line music perception test including the Scale subtest of Montreal Battery of Evaluation of Amusia (MBEA) and Off-Beat and Out-of-key tasks as well as a prosodic verbal task that measures the perception of word stress. Regression analyses showed that there was a clear association between prosody perception and music perception, especially in the domain of rhythm perception. This association was evident after controlling for music education, age, pitch perception, visuospatial perception, and working memory. Pitch perception was significantly associated with music perception but not with prosody perception. The association between music perception and visuospatial perception (measured using analogous tasks) was less clear. Overall, the pattern of results indicates that there is a robust link between music and speech perception and that this link can be mediated by rhythmic cues (time and stress). PMID:24032022

  20. Circadian Rhythms: Hijacking the Cyanobacterial Clock

    PubMed Central

    Hoyle, Nathaniel P.; O’Neill, John S

    2016-01-01

    The production of limitless carbon-free energy is a long-sought dream of scientists and politicians alike. One strategy for achieving this aim is the production of hydrogen by photosynthetic microorganisms – harnessing the effectively limitless power of the sun to power our cars, toasters and PCR machines. It may be tempting to think of host expression systems as miniature factories given over entirely to the production our molecule of interest. However, the biological nature of the host must be taken into account if we are to maximize productivity. The circadian rhythm, an organism’s entrainable oscillation of biological processes with a period of around 24 hours, is one such aspect that has received scant attention but is likely to be of particular importance to photosynthetic host systems. In this issue of current biology Xu et al. describe how our knowledge of the Synechococcus elongatus circadian clock can be leveraged to improve the production of exogeneous proteins, including those involved in the production of hydrogen [1]. PMID:24309283

  1. Modeling activity rhythms in fiddler crabs.

    PubMed

    Dugaw, Christopher J; Honeyfield, Rebecca; Taylor, Caz M; Verzi, Diana W

    2009-10-01

    Burrowing crabs of the genus Uca inhabit tidal mudflats and beaches. They feed actively during low tide and remain in their burrows when the tide is high. The timing of this activity has been shown to persist in the absence of external light and tidal cues, indicating the presence of an internal timing mechanism. Researchers report the persistence of several variations in locomotor activity under laboratory conditions that cannot be explained by a single circatidal clock. Previous studies supported two alternative hypotheses: the presence of either two circalunidian clocks, or a circadian and circatidal clock to regulate these activity rhythms. In this paper, we formulate mathematical models to describe and test these hypotheses. The models suggested by the literature contain some important differences beyond the frequency of proposed clocks, and these are reflected in the mathematical formulations and simulation results. One hypothesis suggests independent phase oscillators, while the other hypothesis suggests that they are coupled in anti-phase. Neither model is able to recover all of the variations in locomotor acitivity observed under laboratory conditions. However, we propose a new model that incorporates aspects of both existing hypotheses and is able to reproduce all laboratory observations. PMID:19916836

  2. Influences of horizontal hypokinesia on performance and circadian physiological rhythms in female humans

    NASA Technical Reports Server (NTRS)

    Winget, C. M.; Deroshia, C. W.; Sandler, H.

    1982-01-01

    Eight females from 35-45 yr of age were subjected to seven days of ambulatory control, seven days of bed rest, and a five day recovery period, with 30 min of centrifugation on day seven of bedrest to determine the effects of weightlessness on the circadian rhythms of females in that age group. Heart rate and rectal temperature (RT) were monitored and each subject was tested in a flight simulator twice a day in conditions of varying levels of turbulence. The flight simulations were run during the morning and acrophase of the circadian RT and performance errors wery monitored for 6 min. No significant differences were detected in the group performance data pre-, during, and post-bedrest, although better performance in the simulator was observed after the centrifuge exposure. An RT phase shift was statistically significant between pre- and during bedrest stages.

  3. A healthy heart is not a metronome: an integrative review of the heart's anatomy and heart rate variability

    PubMed Central

    Shaffer, Fred; McCraty, Rollin; Zerr, Christopher L.

    2014-01-01

    Heart rate variability (HRV), the change in the time intervals between adjacent heartbeats, is an emergent property of interdependent regulatory systems that operate on different time scales to adapt to challenges and achieve optimal performance. This article briefly reviews neural regulation of the heart, and its basic anatomy, the cardiac cycle, and the sinoatrial and atrioventricular pacemakers. The cardiovascular regulation center in the medulla integrates sensory information and input from higher brain centers, and afferent cardiovascular system inputs to adjust heart rate and blood pressure via sympathetic and parasympathetic efferent pathways. This article reviews sympathetic and parasympathetic influences on the heart, and examines the interpretation of HRV and the association between reduced HRV, risk of disease and mortality, and the loss of regulatory capacity. This article also discusses the intrinsic cardiac nervous system and the heart-brain connection, through which afferent information can influence activity in the subcortical and frontocortical areas, and motor cortex. It also considers new perspectives on the putative underlying physiological mechanisms and properties of the ultra-low-frequency (ULF), very-low-frequency (VLF), low-frequency (LF), and high-frequency (HF) bands. Additionally, it reviews the most common time and frequency domain measurements as well as standardized data collection protocols. In its final section, this article integrates Porges' polyvagal theory, Thayer and colleagues' neurovisceral integration model, Lehrer et al.'s resonance frequency model, and the Institute of HeartMath's coherence model. The authors conclude that a coherent heart is not a metronome because its rhythms are characterized by both complexity and stability over longer time scales. Future research should expand understanding of how the heart and its intrinsic nervous system influence the brain. PMID:25324790

  4. Heart Failure

    MedlinePlus

    ... Tiredness and shortness of breath Common causes of heart failure are coronary artery disease, high blood pressure and diabetes. It is more common in people who are 65 years old or older, African Americans, people who are overweight, and people who have ...

  5. Heart Truth

    MedlinePlus

    ... about women’s risk for heart disease―the #1 killer of women in the United States―and share ... t Care What You Wear—It's the #1 Killer of Women ® are registered trademarks of U.S. ...

  6. Heart Rate at Hospital Discharge in Patients With Heart Failure Is Associated With Mortality and Rehospitalization

    PubMed Central

    Laskey, Warren K.; Alomari, Ihab; Cox, Margueritte; Schulte, Phillip J.; Zhao, Xin; Hernandez, Adrian F.; Heidenreich, Paul A.; Eapen, Zubin J.; Yancy, Clyde; Bhatt, Deepak L.; Fonarow, Gregg C.

    2015-01-01

    Background Whether heart rate upon discharge following hospitalization for heart failure is associated with long‐term adverse outcomes and whether this association differs between patients with sinus rhythm (SR) and atrial fibrillation (AF) have not been well studied. Methods and Results We conducted a retrospective cohort study from clinical registry data linked to Medicare claims for 46 217 patients participating in Get With The Guidelines®–Heart Failure. Cox proportional‐hazards models were used to estimate the association between discharge heart rate and all‐cause mortality, all‐cause readmission, and the composite outcome of mortality/readmission through 1 year. For SR and AF patients with heart rate ≥75, the association between heart rate and mortality (expressed as hazard ratio [HR] per 10 beats‐per‐minute increment) was significant at 0 to 30 days (SR: HR 1.30, 95% CI 1.22 to 1.39; AF: HR 1.23, 95% CI 1.16 to 1.29) and 31 to 365 days (SR: HR 1.15, 95% CI 1.12 to 1.20; AF: HR 1.05, 95% CI 1.01 to 1.08). Similar associations between heart rate and all‐cause readmission and the composite outcome were obtained for SR and AF patients from 0 to 30 days but only in the composite outcome for SR patients over the longer term. The HR from 0 to 30 days exceeded that from 31 to 365 days for both SR and AF patients. At heart rates <75, an association was significant for mortality only for both SR and AF patients. Conclusions Among older patients hospitalized with heart failure, higher discharge heart rate was associated with increased risks of death and rehospitalization, with higher risk in the first 30 days and for SR compared with AF. PMID:25904590

  7. Women's Heart Disease: Heart Attack Symptoms

    MedlinePlus

    ... this page please turn JavaScript on. Feature: Women's Heart Disease Heart Attack Symptoms Past Issues / Winter 2014 Table ... NHLBI has uncovered some of the causes of heart diseases and conditions, as well as ways to prevent ...

  8. After Heart Attack, New Threat: Heart Failure

    MedlinePlus

    ... of heart attack known as STEMI (ST elevation myocardial infarction). "Patients with ischemic heart disease are at the ... failure]. This includes those who have had a myocardial infarction, also called heart attack," Gho said. "Research studying ...

  9. Heart Health - Heart Disease: Symptoms, Diagnosis, Treatment

    MedlinePlus

    ... Bar Home Current Issue Past Issues Cover Story Heart Health Heart Disease: Symptoms, Diagnosis, Treatment Past Issues / Winter 2009 ... of this page please turn Javascript on. Most heart attacks happen when a clot in the coronary ...

  10. Heart Health: The Heart Truth Campaign 2009

    MedlinePlus

    ... Bar Home Current Issue Past Issues Cover Story Heart Health The Heart Truth Campaign 2009 Past Issues / Winter 2009 Table ... one of the celebrities supporting this year's The Heart Truth campaign. Both R&B singer Ashanti (center) ...

  11. Heart Health - Heart Disease: Symptoms, Diagnosis, Treatment

    MedlinePlus

    ... Issues Cover Story Heart Health Heart Disease: Symptoms, Diagnosis, Treatment Past Issues / Winter 2009 Table of Contents ... or both arms, the neck, jaw, or stomach. Diagnosis Key heart tests include: Electrocardiogram (ECG or EKG) — ...

  12. Patterns of body size and adiposity among UK children of South Asian, black African–Caribbean and white European origin: Child Heart And health Study in England (CHASE Study)

    PubMed Central

    Nightingale, Claire M; Rudnicka, Alicja R; Owen, Chris G; Cook, Derek G; Whincup, Peter H

    2011-01-01

    Background The objective of this study was to examine adiposity patterns in UK South Asian, black African–Caribbean and white European children using a range of adiposity markers. A cross-sectional survey in London, Birmingham and Leicester primary schools was conducted. Weight, height, waist circumference, skinfold thickness values (biceps, triceps, subscapular and suprailiac) were measured. Fat mass was derived from bioimpedance; optimally height-standardized indices were derived for all adiposity markers. Ethnic origin was based on parental self-report. Multilevel models were used to obtain adjusted means and ethnic differences adjusted for gender, age, month, observer and school (fitted as a random effect). A total of 5887 children aged 9–10 years participated (response rate 68%), including 1345 white Europeans, 1523 South Asians and 1570 black African–Caribbeans. Results Compared with white Europeans, South Asians had a higher sum of all skinfolds and fat mass percentage, and their body mass index (BMI) was lower. South Asians were slightly shorter but use of optimally height-standardized indices did not materially affect these comparisons. At any given fat mass, BMI was lower in South Asians than white Europeans. In similar comparisons, black African–Caribbeans had a lower sum of all skinfolds but a higher fat mass percentage, and their BMI was higher. Black African–Caribbeans were markedly taller. Use of optimally height-standardized indices yielded markedly different findings; sum of skinfolds index was markedly lower, whereas fat mass index and weight-for-height index were similar. At any given fat mass, BMI was similar in black African–Caribbeans and white Europeans. Conclusions UK South Asian children have higher adiposity levels and black African–Caribbeans have similar or lower adiposity levels when compared with white Europeans. However, these differences are not well represented by comparisons based on BMI, which systematically

  13. Keeping a Beat on the Heart

    NASA Technical Reports Server (NTRS)

    Liszka, Kathy J.; Mackin, Michael A.; Liehter, Michael J.; York, David W.; Pillai, Dilip; Rosenbaum, David S.

    2005-01-01

    Feel the relief of a patient suffering from heart arrhythmia, who is able to return home while having her heart monitored by health professionals 24 hours a day, without the fear that she will miss an important indicator and suffer a fatal heart attack - using technology originally developed to conduct experiments on the Space Shuttle. Approximately 400,000 Americans die every year from sudden heart attacks . Medical research revealed that patterns of electrical activity in the heart can act as predictors of these lethal cardiac events known as arrhythmias. Fortunately, certain arrhythmias such as ventricular fibrillation (loss of regular heartbeat and subsequent loss of function) and ventricular tachycardia (rapid heartbeats), can be detected and appropriately treated. Today, patients at moderate risk of arrhythmias can benefit from technology that would permit long- term continuous monitoring of electrical cardiac rhythms outside the hospital environment in the comfort of their own homes. Medical telemetry systems, also known as telemedicine, are evolving rapidly as wireless communication technology advances, evidenced by the commercial products and research prototypes for remote health monitoring that have appeared in recent years. Wireless systems allow patients to move freely in their home and work environment while being monitored remotely by health care professionals.

  14. A Neocortical Delta Rhythm Facilitates Reciprocal Interlaminar Interactions via Nested Theta Rhythms

    PubMed Central

    Carracedo, Lucy M.; Kjeldsen, Henrik; Cunnington, Leonie; Jenkins, Alastair; Schofield, Ian; Cunningham, Mark O.; Davies, Ceri H.; Traub, Roger D.

    2013-01-01

    Delta oscillations (1–4 Hz) associate with deep sleep and are implicated in memory consolidation and replay of cortical responses elicited during wake states. A potent local generator has been characterized in thalamus, and local generators in neocortex have been suggested. Here we demonstrate that isolated rat neocortex generates delta rhythms in conditions mimicking the neuromodulatory state during deep sleep (low cholinergic and dopaminergic tone). The rhythm originated in an NMDA receptor-driven network of intrinsic bursting (IB) neurons in layer 5, activating a source of GABAB receptor-mediated inhibition. In contrast, regular spiking (RS) neurons in layer 5 generated theta-frequency outputs. In layer 2/3 principal cells, outputs from IB cells associated with IPSPs, whereas those from layer 5 RS neurons related to nested bursts of theta-frequency EPSPs. Both interlaminar spike and field correlations revealed a sequence of events whereby sparse spiking in layer 2/3 was partially reflected back from layer 5 on each delta period. We suggest that these reciprocal, interlaminar interactions may represent a “Helmholtz machine”-like process to control synaptic rescaling during deep sleep. PMID:23804097

  15. Pediatric heart surgery - discharge

    MedlinePlus

    ... reduced appetite Alternate Names Congenital heart surgery - discharge; Patent ductus arteriosus ligation - discharge; Hypoplastic left heart repair - ... of the aorta Congenital heart defect - corrective surgery Patent ductus arteriosus Pediatric heart surgery Tetralogy of Fallot ...

  16. Problem: Heart Valve Regurgitation

    MedlinePlus

    ... Pressure High Blood Pressure Tools & Resources Stroke More Problem: Heart Valve Regurgitation Updated:May 26,2016 What ... content was last reviewed May 2016. Heart Valve Problems and Disease • Home • About Heart Valves • Heart Valve ...

  17. Problem: Heart Valve Stenosis

    MedlinePlus

    ... Pressure High Blood Pressure Tools & Resources Stroke More Problem: Heart Valve Stenosis Updated:Aug 10,2016 About ... content was last reviewed May 2016. Heart Valve Problems and Disease • Home • About Heart Valves • Heart Valve ...

  18. Heart attack first aid

    MedlinePlus

    First aid - heart attack; First aid - cardiopulmonary arrest; First aid - cardiac arrest ... A heart attack occurs when the blood flow that carries oxygen to the heart is blocked. The heart muscle ...

  19. About Heart Attacks

    MedlinePlus

    ... survive. A heart attack occurs when the blood flow that brings oxygen to the heart muscle is severely reduced or ... survive. A heart attack occurs when the blood flow that brings oxygen to the heart muscle is severely reduced or ...

  20. Heart disease - resources

    MedlinePlus

    Resources - heart disease ... The following organizations are good resources for information on heart disease: American Heart Association -- www.heart.org Centers for Disease Control and Prevention -- www.cdc.gov/heartdisease

  1. What Causes Heart Block?

    MedlinePlus

    ... or inflammation of the heart muscle. Heart failure . Rheumatic (roo-MAT-ik) fever. Cardiomyopathy (KAR-de-o-mi-OP-a-the), or heart muscle diseases. Other diseases may increase the risk of heart ...

  2. Congenital heart disease

    MedlinePlus

    Congenital heart disease is a problem with the heart's structure and function that is present at birth. ... Congenital heart disease (CHD) can describe a number of different problems affecting the heart. It is the most common ...

  3. Heart CT scan

    MedlinePlus

    ... arteries to determine your risk for heart disease Congenital heart disease (heart problems that are present at birth) Problems ... Abnormal results may be due to: Aneurysm Congenital heart disease ... Narrowing of one or more coronary arteries (coronary artery ...

  4. Heart Attack Risk Assessment

    MedlinePlus

    ... Pressure Tools & Resources Stroke More Heart Attack Risk Assessment Updated:May 31,2016 We're sorry, but ... Can You Recognize a Heart Attack? Quiz Risk Assessment Patient Information Sheets: Heart Attack Heart Attack Personal ...

  5. Pediatric heart surgery

    MedlinePlus

    Heart surgery - pediatric; Heart surgery for children; Acquired heart disease; Heart valve surgery - children ... after the baby is born. For others, your child may be able to safely wait for months ...

  6. Cancer Now Leading Killer in 12 European Nations

    MedlinePlus

    ... be collected and compared between countries "so that health professionals and national governments can target interventions more effectively to reduce inequalities," he said. SOURCE: European Heart Journal , news release, ...

  7. Brain Rhythms Reveal a Hierarchical Network Organization

    PubMed Central

    Steinke, G. Karl; Galán, Roberto F.

    2011-01-01

    Recordings of ongoing neural activity with EEG and MEG exhibit oscillations of specific frequencies over a non-oscillatory background. The oscillations appear in the power spectrum as a collection of frequency bands that are evenly spaced on a logarithmic scale, thereby preventing mutual entrainment and cross-talk. Over the last few years, experimental, computational and theoretical studies have made substantial progress on our understanding of the biophysical mechanisms underlying the generation of network oscillations and their interactions, with emphasis on the role of neuronal synchronization. In this paper we ask a very different question. Rather than investigating how brain rhythms emerge, or whether they are necessary for neural function, we focus on what they tell us about functional brain connectivity. We hypothesized that if we were able to construct abstract networks, or “virtual brains”, whose dynamics were similar to EEG/MEG recordings, those networks would share structural features among themselves, and also with real brains. Applying mathematical techniques for inverse problems, we have reverse-engineered network architectures that generate characteristic dynamics of actual brains, including spindles and sharp waves, which appear in the power spectrum as frequency bands superimposed on a non-oscillatory background dominated by low frequencies. We show that all reconstructed networks display similar topological features (e.g. structural motifs) and dynamics. We have also reverse-engineered putative diseased brains (epileptic and schizophrenic), in which the oscillatory activity is altered in different ways, as reported in clinical studies. These reconstructed networks show consistent alterations of functional connectivity and dynamics. In particular, we show that the complexity of the network, quantified as proposed by Tononi, Sporns and Edelman, is a good indicator of brain fitness, since virtual brains modeling diseased states display lower

  8. Circadian Rhythms in Floral Scent Emission.

    PubMed

    Fenske, Myles P; Imaizumi, Takato

    2016-01-01

    To successfully recruit pollinators, plants often release attractive floral scents at specific times of day to coincide with pollinator foraging. This timing of scent emission is thought to be evolutionarily beneficial to maximize resource efficiency while attracting only useful pollinators. Temporal regulation of scent emission is tied to the activity of the specific metabolic pathways responsible for scent production. Although floral volatile profiling in various plants indicated a contribution by the circadian clock, the mechanisms by which the circadian clock regulates timing of floral scent emission remained elusive. Recent studies using two species in the Solanaceae family provided initial insight into molecular clock regulation of scent emission timing. In Petunia hybrida, the floral volatile benzenoid/phenylpropanoid (FVBP) pathway is the major metabolic pathway that produces floral volatiles. Three MYB-type transcription factors, ODORANT 1 (ODO1), EMISSION OF BENZENOIDS I (EOBI), and EOBII, all of which show diurnal rhythms in mRNA expression, act as positive regulators for several enzyme genes in the FVBP pathway. Recently, in P. hybrida and Nicotiana attenuata, homologs of the Arabidopsis clock gene LATE ELONGATED HYPOCOTYL (LHY) have been shown to have a similar role in the circadian clock in these plants, and to also determine the timing of scent emission. In addition, in P. hybrida, PhLHY directly represses ODO1 and several enzyme genes in the FVBP pathway during the morning as an important negative regulator of scent emission. These findings facilitate our understanding of the relationship between a molecular timekeeper and the timing of scent emission, which may influence reproductive success. PMID:27148293

  9. Circadian Rhythms in Floral Scent Emission

    PubMed Central

    Fenske, Myles P.; Imaizumi, Takato

    2016-01-01

    To successfully recruit pollinators, plants often release attractive floral scents at specific times of day to coincide with pollinator foraging. This timing of scent emission is thought to be evolutionarily beneficial to maximize resource efficiency while attracting only useful pollinators. Temporal regulation of scent emission is tied to the activity of the specific metabolic pathways responsible for scent production. Although floral volatile profiling in various plants indicated a contribution by the circadian clock, the mechanisms by which the circadian clock regulates timing of floral scent emission remained elusive. Recent studies using two species in the Solanaceae family provided initial insight into molecular clock regulation of scent emission timing. In Petunia hybrida, the floral volatile benzenoid/phenylpropanoid (FVBP) pathway is the major metabolic pathway that produces floral volatiles. Three MYB-type transcription factors, ODORANT 1 (ODO1), EMISSION OF BENZENOIDS I (EOBI), and EOBII, all of which show diurnal rhythms in mRNA expression, act as positive regulators for several enzyme genes in the FVBP pathway. Recently, in P. hybrida and Nicotiana attenuata, homologs of the Arabidopsis clock gene LATE ELONGATED HYPOCOTYL (LHY) have been shown to have a similar role in the circadian clock in these plants, and to also determine the timing of scent emission. In addition, in P. hybrida, PhLHY directly represses ODO1 and several enzyme genes in the FVBP pathway during the morning as an important negative regulator of scent emission. These findings facilitate our understanding of the relationship between a molecular timekeeper and the timing of scent emission, which may influence reproductive success. PMID:27148293

  10. 256-slice CT coronary angiography in atrial fibrillation: The impact of mean heart rate and heart rate variability on image quality

    NASA Astrophysics Data System (ADS)

    Chen, Liang-Kuang; Hsu, Shih-Ming; Mok, Greta S. P.; Law, Wei-Yip; Lu, Kun-Mu; Yang, Ching-Ching; Wu, Tung-Hsin

    2011-08-01

    The aim of this study was to evaluate the image quality of 256-MDCT in atrial fibrillation and to compare the findings with those among patients in sinus rhythm.MaterialsAll reconstructed images were evaluated by two independent experienced readers blinded to patient information, heart rate, and ECG results to assess the diagnostic quality of images of the coronary artery segments using axial images, multi-planar reformations, maximum intensity projections, and volume rendering technique.ResultsNo statistical significance was detected in terms of the overall image quality between patients in sinus rhythm and with atrial fibrillation. Pearson's correlation analysis showed no significant association between image quality and mean heart rate no matter for patients in sinus rhythm or with atrial fibrillation. Similarly, there was no correlation between image quality and heart rate variability for either patients in sinus rhythm or with atrial fibrillation. Our results showed that the optimal reconstruction window depends on patient's HR, and the pattern for patients in atrial fibrillation is similar to that obtained from non-atrial fibrillation patients.ConclusionThis study shows the potential of using 256-MDCT coronary angiography in patients with atrial fibrillation. Our results suggest that when appropriate reconstruction timing window is applied, patients with atrial fibrillation do not have to be excluded from MDCT coronary angiographic examinations.

  11. Heart Failure Update: Inpatient Management.

    PubMed

    Korabathina, Ravi

    2016-03-01

    Acute decompensated heart failure (HF) is one of most common reasons for hospitalization among individuals older than 65 years. A thorough evaluation, including history, physical examination, and laboratory assessment, is required to optimize care of these patients. In uncertain cases, serum brain-type natriuretic peptide (BNP) or N-terminal proBNP level, stress testing, and/or invasive coronary angiography may be helpful in establishing the diagnosis. The hospital setting provides an opportunity to identify etiologies and stabilize the patient. The primary goal of inpatient HF therapy is systemic and pulmonary decongestion, achieved most effectively using intravenous diuretic therapy. Rate and rhythm control may be needed for patients with concurrent atrial fibrillation and, in American College of Cardiology/American Heart Association stage D HF, intravenous inotropes may become necessary. New pharmacologic or device therapies also are considered as a means of transitioning patients, especially those with severe disease, to the outpatient setting. Patients hospitalized for acute decompensated HF have high postdischarge mortality and rehospitalization rates and, thus, should be monitored carefully. PMID:26974002

  12. Heart Disease in Women

    MedlinePlus

    ... United States, 1 in 4 women dies from heart disease. In fact, coronary heart disease (CHD)—the most common type of heart ... heart information http://womenshealth.gov/publications/our-publications/fact-sheet/heart-disease.html New Heart Guidelines Released; Talk to ...

  13. Pediatric heart surgery

    MedlinePlus

    Heart surgery - pediatric; Heart surgery for children; Acquired heart disease; Heart valve surgery - children ... There are many kinds of heart defects. Some are minor, and others are more serious. Defects can occur inside the heart or in the large blood vessels ...

  14. [Comparison of amiodarone and quinidine in the conversion to sinusal rhythm of atrial fibrillation of recent onset].

    PubMed

    Negrini, M; Gibelli, G; De Ponti, C

    1990-03-01

    The effectiveness of amiodarone and quinidine in converting atrial fibrillation of recent onset (less than three weeks) to sinus rhythm was compared in a randomized, open-label study. Patients with signs of heart failure determining a NYHA class 3 or 4, acute myocardial infarction, unstable angina pectoris, sick sinus syndrome, Wolff-Parkinson-White syndrome, conduction disturbances, dysthyroidism, or undergoing concomitant therapy with antiarrhythmic drugs, were excluded from the study. Sixty-eight consecutive patients were randomized to receive amiodarone (group A) or quinidine (group B). Group A was treated with amiodarone intravenously as a bolus of 5 mg/Kg over a 20 min period followed by a 15 mg/Kg infusion during the first 24 hours and then orally at a dose of 0.4 g every 6 hours. Group B was treated with quinidine sulphate orally at a dose of 0.2 g every 6 hours during the first day; 0.4 g every 6 hours the second day and 0.6 g every 6 hours during the third day of therapy. Quinidine was preceded by rapid intravenous digitalization depending on the patient's clinical status so as to obtain a ventricular rate of about 100 beats/min, with subsequent oral digitalis administration in maintenance doses. Both treatments were continued until conversion or for a maximum of three days. If the sinus rhythm was not restored, patients underwent electrical cardioversion. Drug efficacy was assessed on the basis of conversion to sinus rhythm. Six patients converted to sinus rhythm with intravenous digitalization alone and were excluded from the comparison between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2344898

  15. Heart Research

    NASA Technical Reports Server (NTRS)

    1991-01-01

    James Antaki and a group of researchers from the University of Pittsburgh School of Medicine used many elements of the Technology Utilization Program while looking for a way to visualize and track material points within the heart muscle. What they needed were tiny artificial "eggs" containing copper sulfate solution, small enough (about 2 mm in diameter) that they would not injure the heart, and large enough to be seen in Magnetic Resonance Imaging (MRI) images; they also had to be biocompatible and tough enough to withstand the beating of the muscle. The group could not make nor buy sufficient containers. After reading an article on microspheres in NASA Tech Briefs, and a complete set of reports on microencapsulation from the Jet Propulsion Laboratory (JPL), JPL put Antaki in touch with Dr.Taylor Wang of Vanderbilt University who helped construct the myocardial markers. The research is expected to lead to improved understanding of how the heart works and what takes place when it fails.

  16. Restart the heart.

    PubMed

    Klingberg, Karsten; Srivastava, David

    2016-01-01

    Early bystander cardiopulmonary resuscitation and rapid defibrillation are the most important factors for favourable outcomes after out of hospital cardiac arrest (OHCA)-as the new American Heart Association/European Resuscitation Council (AHA/ERC) guidelines emphasise. The patient in our case was a healthy young man who had a witnessed cardiac arrest due to a chest collision with the goalkeeper during a football match. Basic life support was immediately provided by his teammates until an automated external defibrillator was brought to the scene. Blunt cardiac injury (BCI) may result in injured myocardium or arrhythmias. Ventricular fibrillation due to BCI in absence of structural cardiac disease is one of the main causes of OHCA in young healthy athletes with high mortality rates. We demonstrate important aspects of the recently released guidelines on cardiac arrest and the chain of survival by the leading societies. PMID:26968838

  17. A stochastic model of input effectiveness during irregular gamma rhythms.

    PubMed

    Dumont, Grégory; Northoff, Georg; Longtin, André

    2016-02-01

    Gamma-band synchronization has been linked to attention and communication between brain regions, yet the underlying dynamical mechanisms are still unclear. How does the timing and amplitude of inputs to cells that generate an endogenously noisy gamma rhythm affect the network activity and rhythm? How does such "communication through coherence" (CTC) survive in the face of rhythm and input variability? We present a stochastic modelling approach to this question that yields a very fast computation of the effectiveness of inputs to cells involved in gamma rhythms. Our work is partly motivated by recent optogenetic experiments (Cardin et al. Nature, 459(7247), 663-667 2009) that tested the gamma phase-dependence of network responses by first stabilizing the rhythm with periodic light pulses to the interneurons (I). Our computationally efficient model E-I network of stochastic two-state neurons exhibits finite-size fluctuations. Using the Hilbert transform and Kuramoto index, we study how the stochastic phase of its gamma rhythm is entrained by external pulses. We then compute how this rhythmic inhibition controls the effectiveness of external input onto pyramidal (E) cells, and how variability shapes the window of firing opportunity. For transferring the time variations of an external input to the E cells, we find a tradeoff between the phase selectivity and depth of rate modulation. We also show that the CTC is sensitive to the jitter in the arrival times of spikes to the E cells, and to the degree of I-cell entrainment. We further find that CTC can occur even if the underlying deterministic system does not oscillate; quasicycle-type rhythms induced by the finite-size noise retain the basic CTC properties. Finally a resonance analysis confirms the relative importance of the I cell pacing for rhythm generation. Analysis of whole network behaviour, including computations of synchrony, phase and shifts in excitatory-inhibitory balance, can be further sped up by orders of

  18. Optimized Treatment and Heart Rate Reduction in Chronic Heart Failure

    PubMed Central

    Moreno, Irineu Blanco; Del Carlo, Carlos Henrique; Pereira-Barretto, Antônio Carlos

    2013-01-01

    Background Heart failure (HF) is a syndrome that leads to poor outcome in advanced forms. The neurohormonal blockade modifies this natural history; however, it is often suboptimal. Objective The aim of this study is to assess at what percentage cardiologists used to treating HF can prescribe target doses of drugs of proven efficacy. Methods A total of 104 outpatients with systolic dysfunction were consecutively enrolled, all under stabilized treatment. Demographic and treatment data were evaluated and the doses achieved were verified. The findings are shown as percentages and correlations are made between different variables. Results The mean age of patients was 64.1 ± 14.2 years, with SBP =115.4 ± 15.3, HR = 67.8 ± 9.4 bpm, weight = 76.0 ± 17.0 kg and sinus rhythm (90.4%). As for treatment, 93.3% received a RAS blocker (ACEI 52.9%), all received beta-blockers (BB), the most often prescribed being carvedilol (92.3%). As for the doses: 97.1% of those receiving an ARB were below the optimal dose and of those who received ACEI, 52.7% received an optimized dose. As for the BB, target doses were prescribed to 76.0% of them. In this group of patients, most with BB target dose, it can be seen that 36.5% had HR ≥ 70 bpm in sinus rhythm. Conclusion Cardiologists used to treating HF can prescribe target doses of ACEI and BB to most patients. Even though they receive the recommended doses, about one third of patients persists with HR > 70 bpm and should have their treatment optimized. PMID:24100693

  19. Circadian rhythms and addiction: Mechanistic insights and future directions

    PubMed Central

    Logan, Ryan W.; Williams, Wilbur P.; McClung, Colleen A.

    2014-01-01

    Circadian rhythms are prominent in many physiological and behavioral functions. Circadian disruptions either by environmental or molecular perturbation can have profound health consequences, including the development and progression of addiction. Both animal and humans studies indicate extensive bidirectional relationships between the circadian system and drugs of abuse. Addicted individuals display disrupted rhythms, and chronic disruption or particular chronotypes, may increase the risk for substance abuse and relapse. Moreover, polymorphisms in circadian genes and an evening chronotype have been linked to mood and addiction disorders, and recent efforts suggest an association with the function of reward neurocircuitry. Animal studies are beginning to determine how altered circadian gene function results in drug induced neuroplasticity and behaviors. Many studies suggest a critical role for circadian rhythms in reward-related pathways in the brain and indicate that drugs of abuse directly affect the central circadian pacemaker. In this review, we highlight key findings demonstrating the importance of circadian rhythms in addiction, and how future studies will reveal important mechanistic insights into the involvement of circadian rhythms in drug addiction. PMID:24731209

  20. Rain reverses diel activity rhythms in an estuarine teleost

    PubMed Central

    Payne, Nicholas L.; van der Meulen, Dylan E.; Gannon, Ruan; Semmens, Jayson M.; Suthers, Iain M.; Gray, Charles A.; Taylor, Matthew D.

    2013-01-01

    Activity rhythms are ubiquitous in nature, and generally synchronized with the day–night cycle. Several taxa have been shown to switch between nocturnal and diurnal activity in response to environmental variability, and these relatively uncommon switches provide a basis for greater understanding of the mechanisms and adaptive significance of circadian (approx. 24 h) rhythms. Plasticity of activity rhythms has been identified in association with a variety of factors, from changes in predation pressure to an altered nutritional or social status. Here, we report a switch in activity rhythm that is associated with rainfall. Outside periods of rain, the estuarine-associated teleost Acanthopagrus australis was most active and in shallower depths during the day, but this activity and depth pattern was reversed in the days following rain, with diurnality restored as estuarine conductivity and turbidity levels returned to pre-rain levels. Although representing the first example of a rain-induced reversal of activity rhythm in an aquatic animal of which we are aware, our results are consistent with established models on the trade-offs between predation risk and foraging efficiency. PMID:23173211

  1. p38 MAP kinase regulates circadian rhythms in Drosophila.

    PubMed

    Vrailas-Mortimer, Alysia D; Ryan, Sarah M; Avey, Matthew J; Mortimer, Nathan T; Dowse, Harold; Sanyal, Subhabrata

    2014-12-01

    The large repertoire of circadian rhythms in diverse organisms depends on oscillating central clock genes, input pathways for entrainment, and output pathways for controlling rhythmic behaviors. Stress-activated p38 MAP Kinases (p38K), although sparsely investigated in this context, show circadian rhythmicity in mammalian brains and are considered part of the circadian output machinery in Neurospora. We find that Drosophila p38Kb is expressed in clock neurons, and mutants in p38Kb either are arrhythmic or have a longer free-running periodicity, especially as they age. Paradoxically, similar phenotypes are observed through either transgenic inhibition or activation of p38Kb in clock neurons, suggesting a requirement for optimal p38Kb function for normal free-running circadian rhythms. We also find that p38Kb genetically interacts with multiple downstream targets to regulate circadian locomotor rhythms. More specifically, p38Kb interacts with the period gene to regulate period length and the strength of rhythmicity. In addition, we show that p38Kb suppresses the arrhythmic behavior associated with inhibition of a second p38Kb target, the transcription factor Mef2. Finally, we find that manipulating p38K signaling in free-running conditions alters the expression of another downstream target, MNK/Lk6, which has been shown to cycle with the clock and to play a role in regulating circadian rhythms. These data suggest that p38Kb may affect circadian locomotor rhythms through the regulation of multiple downstream pathways. PMID:25403440

  2. Development of auditory-specific brain rhythm in infants.

    PubMed

    Fujioka, Takako; Mourad, Nasser; Trainor, Laurel J

    2011-02-01

    Human infants rapidly develop their auditory perceptual abilities and acquire culture-specific knowledge in speech and music in the second 6 months of life. In the adult brain, neural rhythm around 10 Hz in the temporal lobes is thought to reflect sound analysis and subsequent cognitive processes such as memory and attention. To study when and how such rhythm emerges in infancy, we examined electroencephalogram (EEG) recordings in infants 4 and 12 months of age during sound stimulation and silence. In the 4-month-olds, the amplitudes of narrowly tuned 4-Hz brain rhythm, recorded from bilateral temporal electrodes, were modulated by sound stimuli. In the 12-month-olds, the sound-induced modulation occurred at faster 6-Hz rhythm at temporofrontal locations. The brain rhythms in the older infants consisted of more complex components, as even evident in individual data. These findings suggest that auditory-specific rhythmic neural activity, which is already established before 6 months of age, involves more speed-efficient long-range neural networks by the age of 12 months when long-term memory for native phoneme representation and for musical rhythmic features is formed. We suggest that maturation of distinct rhythmic components occurs in parallel, and that sensory-specific functions bound to particular thalamo-cortical networks are transferred to newly developed higher-order networks step by step until adult hierarchical neural oscillatory mechanisms are achieved across the whole brain. PMID:21226773

  3. Seasonal variations in daily rhythms of activity in athletic horses.

    PubMed

    Bertolucci, C; Giannetto, C; Fazio, F; Piccione, G

    2008-07-01

    Circadian rhythms reflect extensive programming of biological activity that meets and exploits the challenges and opportunities offered by the periodic nature of the environment. In the present investigation, we recorded the total activity of athletic horses kept at four different times of the year (vernal equinox, summer solstice, autumn equinox and winter solstice), to evaluate the presence of seasonal variations of daily activity rhythms. Athletic Thoroughbred horses were kept in individual boxes with paddock. Digitally integrated measure of total activity of each mare was continuously recorded by actigraphy-based data loggers. Horse total activities were not evenly distributed over the day, but they were mainly diurnal during the year. Daily activity rhythms showed clear seasonal variations, with the highest daily amount of activity during the vernal equinox and the lowest during the winter solstice. Interestingly, the amount of activity during either photophase or scotophase changed significantly throughout the year. Circadian analysis of horse activities showed that the acrophase, the estimated time at which the peak of the rhythm occurs, did not change during the year, it always occurred in the middle of the photoperiod. Analysing the time structure of long-term and continuously measured activity and feeding could be a useful method to critically evaluate athletic horse management systems in which spontaneous locomotor activity and feeding are severely limited. Circadian rhythms are present in several elements of sensory motor and psychomotor functions and these would be taken into consideration to plan the training schedules and competitions in athletic horses. PMID:22443706

  4. Establishment of human cell lines showing circadian rhythms of bioluminescence.

    PubMed

    Yoshikawa, Aki; Shimada, Hiroko; Numazawa, Kahori; Sasaki, Tsukasa; Ikeda, Masaaki; Kawashima, Minae; Kato, Nobumasa; Tokunaga, Katsushi; Ebisawa, Takashi

    2008-11-28

    We have established human retinal pigment epithelial cell lines stably expressing the luciferase gene, driven by the human Bmal1 promoter, to obtain human-derived cells that show circadian rhythms of bioluminescence after dexamethasone treatment. The average circadian period of bioluminescence for the obtained clones was 24.07+/-0.48 h. Lithium (10 mM) in the medium significantly lengthened the circadian period of bioluminescence, which is consistent with previous reports, while 2 mM or 5 mM lithium had no effect. This is the first report on the establishment of human-derived cell lines that proliferate infinitely and show circadian rhythms of bioluminescence, and also the first to investigate the effects of low-dose lithium on the circadian rhythms of human-derived cells in vitro. The established cells will be useful for various in vitro studies of human circadian rhythms and for the development of new therapies for human disorders related to circadian rhythm disturbances. PMID:18809466

  5. Social Rhythm and Mental Health: A Cross-Cultural Comparison

    PubMed Central

    Margraf, Jürgen; Lavallee, Kristen; Zhang, XiaoChi; Schneider, Silvia

    2016-01-01

    Background Social rhythm refers to the regularity with which one engages in social activities throughout the week, and has established links with bipolar disorder, as well as some links with depression and anxiety. The aim of the present study is to examine social rhythm and its relationship to various aspects of health, including physical health, negative mental health, and positive mental health. Method Questionnaire data were obtained from a large-scale multi-national sample of 8095 representative participants from the U.S., Russia, and Germany. Results Results indicated that social rhythm irregularity is related to increased reporting of health problems, depression, anxiety, and stress. In contrast, greater regularity is related to better overall health state, life satisfaction, and positive mental health. The effects are generally small in size, but hold even when controlling for gender, marital status, education, income, country, and social support. Further, social rhythm means differ across Russia, the U.S., and Germany. Relationships with mental health are present in all three countries, but differ in magnitude. Conclusions Social rhythm irregularity is related to mental health in Russia, the U.S., and Germany. PMID:26954568

  6. Glucocorticoids Play a Key Role in Circadian Cell Cycle Rhythms

    PubMed Central

    Dickmeis, Thomas; Lahiri, Kajori; Nica, Gabriela; Vallone, Daniela; Santoriello, Cristina; Neumann, Carl J; Hammerschmidt, Matthias; Foulkes, Nicholas S

    2007-01-01

    Clock output pathways play a pivotal role by relaying timing information from the circadian clock to a diversity of physiological systems. Both cell-autonomous and systemic mechanisms have been implicated as clock outputs; however, the relative importance and interplay between these mechanisms are poorly understood. The cell cycle represents a highly conserved regulatory target of the circadian timing system. Previously, we have demonstrated that in zebrafish, the circadian clock has the capacity to generate daily rhythms of S phase by a cell-autonomous mechanism in vitro. Here, by studying a panel of zebrafish mutants, we reveal that the pituitary–adrenal axis also plays an essential role in establishing these rhythms in the whole animal. Mutants with a reduction or a complete absence of corticotrope pituitary cells show attenuated cell-proliferation rhythms, whereas expression of circadian clock genes is not affected. We show that the corticotrope deficiency is associated with reduced cortisol levels, implicating glucocorticoids as a component of a systemic signaling pathway required for circadian cell cycle rhythmicity. Strikingly, high-amplitude rhythms can be rescued by exposing mutant larvae to a tonic concentration of a glucocorticoid agonist. Our work suggests that cell-autonomous clock mechanisms are not sufficient to establish circadian cell cycle rhythms at the whole-animal level. Instead, they act in concert with a systemic signaling environment of which glucocorticoids are an essential part. PMID:17373855

  7. Cross-sectional study of ethnic differences in physical fitness among children of South Asian, black African–Caribbean and white European origin: the Child Heart and Health Study in England (CHASE)

    PubMed Central

    Nightingale, C M; Donin, A S; Kerry, S R; Owen, C G; Rudnicka, A R; Brage, S; Westgate, K L; Ekelund, U; Cook, D G; Whincup, P H

    2016-01-01

    Objective Little is known about levels of physical fitness in children from different ethnic groups in the UK. We therefore studied physical fitness in UK children (aged 9–10 years) of South Asian, black African–Caribbean and white European origin. Design Cross-sectional study. Setting Primary schools in the UK. Participants 1625 children (aged 9–10 years) of South Asian, black African–Caribbean and white European origin in the UK studied between 2006 and 2007. Outcome measures A step test assessed submaximal physical fitness from which estimated VO2 max was derived. Ethnic differences in estimated VO2 max were estimated using multilevel linear regression allowing for clustering at school level and adjusting for age, sex and month as fixed effects. Results The study response rate was 63%. In adjusted analyses, boys had higher levels of estimated VO2 max than girls (mean difference 3.06 mL O2/min/kg, 95% CI 2.66 to 3.47, p<0.0001). Levels of estimated VO2 max were lower in South Asians than those in white Europeans (mean difference −0.79 mL O2/min/kg, 95% CI −1.41 to −0.18, p=0.01); levels of estimated VO2 max in black African–Caribbeans were higher than those in white Europeans (mean difference 0.60 mL O2/min/kg, 95% CI 0.02 to 1.17, p=0.04); these patterns were similar in boys and girls. The lower estimated VO2 max in South Asians, compared to white Europeans, was consistent among Indian, Pakistani and Bangladeshi children and was attenuated by 78% after adjustment for objectively measured physical activity (average daily steps). Conclusions South Asian children have lower levels of physical fitness than white Europeans and black African–Caribbeans in the UK. This ethnic difference in physical fitness is at least partly explained by ethnic differences in physical activity. PMID:27324713

  8. An unusual case of hematuria in a young female: renal artery embolism, mitral stenosis, and sinus rhythm.

    PubMed

    Kumar, Ashok; Kapoor, Aditya; Kumar, Sudeep

    2016-03-01

    Renal artery embolism (RAE) is an uncommon entity that is most often secondary to a cardiac source. Most reported cases have been in patients with underlying atrial fibrillation (AF), and occurrence of RAE, especially in patients with valvular heart disease, and sinus rhythm is very rare. We describe an unusual case of a young female who presented with sudden onset right flank pain, vomiting, anorexia, and hematuria, and was found to have thrombotic occlusion of the distal right renal artery. Although she denied any previous cardiac history, detailed cardiovascular examination revealed the presence of severe rheumatic mitral stenosis without any evidence of AF or left atrial clot. She was initially managed conservatively using low molecular weight heparin followed by oral anticoagulation with resolution of symptoms. A successful balloon mitral valvotomy was performed six weeks later. The patient is asymptomatic at her last follow-up of six months with preserved renal function. In symptomatic patients, clinicians need to consider the possibility of RAE even in patients of valvular heart disease with underlying sinus rhythm. Appropriate management of the underlying cardiac condition is imperative since embolism may be recurrent leading to compromise of renal function, if left untreated. PMID:26997399

  9. Potent social synchronization can override photic entrainment of circadian rhythms

    PubMed Central

    Fuchikawa, Taro; Eban-Rothschild, Ada; Nagari, Moshe; Shemesh, Yair; Bloch, Guy

    2016-01-01

    Circadian rhythms in behaviour and physiology are important for animal health and survival. Studies with individually isolated animals in the laboratory have consistently emphasized the dominant role of light for the entrainment of circadian rhythms to relevant environmental cycles. Although in nature interactions with conspecifics are functionally significant, social signals are typically not considered important time-givers for the animal circadian clock. Our results challenge this view. By studying honeybees in an ecologically relevant context and using a massive data set, we demonstrate that social entrainment can be potent, may act without direct contact with other individuals and does not rely on gating the exposure to light. We show for the first time that social time cues stably entrain the clock, even in animals experiencing conflicting photic and social environmental cycles. These findings add to the growing appreciation for the importance of studying circadian rhythms in ecologically relevant contexts. PMID:27210069

  10. Body movement selectively shapes the neural representation of musical rhythms.

    PubMed

    Chemin, Baptiste; Mouraux, André; Nozaradan, Sylvie

    2014-12-01

    It is increasingly recognized that motor routines dynamically shape the processing of sensory inflow (e.g., when hand movements are used to feel a texture or identify an object). In the present research, we captured the shaping of auditory perception by movement in humans by taking advantage of a specific context: music. Participants listened to a repeated rhythmical sequence before and after moving their bodies to this rhythm in a specific meter. We found that the brain responses to the rhythm (as recorded with electroencephalography) after body movement were significantly enhanced at frequencies related to the meter to which the participants had moved. These results provide evidence that body movement can selectively shape the subsequent internal representation of auditory rhythms. PMID:25344346

  11. Current conceptual challenges in the study of rhythm processing deficits

    PubMed Central

    Tranchant, Pauline; Vuvan, Dominique T.

    2015-01-01

    Interest in the study of rhythm processing deficits (RPD) is currently growing in the cognitive neuroscience community, as this type of investigation constitutes a powerful tool for the understanding of normal rhythm processing. Because this field is in its infancy, it still lacks a common conceptual vocabulary to facilitate effective communication between different researchers and research groups. In this commentary, we provide a brief review of recent reports of RPD through the lens of one important empirical issue: the method by which beat perception is measured, and the consequences of method selection for the researcher's ability to specify which mechanisms are impaired in RPD. This critical reading advocates for the importance of matching measurement tools to the putative neurocognitive mechanisms under study, and reveals the need for effective and specific assessments of the different aspects of rhythm perception and synchronization. PMID:26106287

  12. Current conceptual challenges in the study of rhythm processing deficits.

    PubMed

    Tranchant, Pauline; Vuvan, Dominique T

    2015-01-01

    Interest in the study of rhythm processing deficits (RPD) is currently growing in the cognitive neuroscience community, as this type of investigation constitutes a powerful tool for the understanding of normal rhythm processing. Because this field is in its infancy, it still lacks a common conceptual vocabulary to facilitate effective communication between different researchers and research groups. In this commentary, we provide a brief review of recent reports of RPD through the lens of one important empirical issue: the method by which beat perception is measured, and the consequences of method selection for the researcher's ability to specify which mechanisms are impaired in RPD. This critical reading advocates for the importance of matching measurement tools to the putative neurocognitive mechanisms under study, and reveals the need for effective and specific assessments of the different aspects of rhythm perception and synchronization. PMID:26106287

  13. Basal forebrain control of wakefulness and cortical rhythms.

    PubMed

    Anaclet, Christelle; Pedersen, Nigel P; Ferrari, Loris L; Venner, Anne; Bass, Caroline E; Arrigoni, Elda; Fuller, Patrick M

    2015-01-01

    Wakefulness, along with fast cortical rhythms and associated cognition, depend on the basal forebrain (BF). BF cholinergic cell loss in dementia and the sedative effect of anti-cholinergic drugs have long implicated these neurons as important for cognition and wakefulness. The BF also contains intermingled inhibitory GABAergic and excitatory glutamatergic cell groups whose exact neurobiological roles are unclear. Here we show that genetically targeted chemogenetic activation of BF cholinergic or glutamatergic neurons in behaving mice produced significant effects on state consolidation and/or the electroencephalogram but had no effect on total wake. Similar activation of BF GABAergic neurons produced sustained wakefulness and high-frequency cortical rhythms, whereas chemogenetic inhibition increased sleep. Our findings reveal a major contribution of BF GABAergic neurons to wakefulness and the fast cortical rhythms associated with cognition. These findings may be clinically applicable to manipulations aimed at increasing forebrain activation in dementia and the minimally conscious state. PMID:26524973

  14. Potent social synchronization can override photic entrainment of circadian rhythms.

    PubMed

    Fuchikawa, Taro; Eban-Rothschild, Ada; Nagari, Moshe; Shemesh, Yair; Bloch, Guy

    2016-01-01

    Circadian rhythms in behaviour and physiology are important for animal health and survival. Studies with individually isolated animals in the laboratory have consistently emphasized the dominant role of light for the entrainment of circadian rhythms to relevant environmental cycles. Although in nature interactions with conspecifics are functionally significant, social signals are typically not considered important time-givers for the animal circadian clock. Our results challenge this view. By studying honeybees in an ecologically relevant context and using a massive data set, we demonstrate that social entrainment can be potent, may act without direct contact with other individuals and does not rely on gating the exposure to light. We show for the first time that social time cues stably entrain the clock, even in animals experiencing conflicting photic and social environmental cycles. These findings add to the growing appreciation for the importance of studying circadian rhythms in ecologically relevant contexts. PMID:27210069

  15. Inositols affect the mating circadian rhythm of Drosophila melanogaster

    PubMed Central

    Sakata, Kazuki; Kawasaki, Haruhisa; Suzuki, Takahiro; Ito, Kumpei; Negishi, Osamu; Tsuno, Takuo; Tsuno, Hiromi; Yamazaki, Youta; Ishida, Norio

    2015-01-01

    Accumulating evidence indicates that the molecular circadian clock underlies the mating behavior of Drosophila melanogaster. However, information about which food components affect circadian mating behavior is scant. The ice plant, Mesembryanthemum crystallinum has recently become a popular functional food. Here, we showed that the close-proximity (CP) rhythm of D. melanogaster courtship behavior was damped under low-nutrient conditions, but significantly enhanced by feeding the flies with powdered ice plant. Among various components of ice plants, we found that myo-inositol increased the amplitude and slightly shortened the period of the CP rhythm. Real-time reporter assays showed that myo-inositol and D-pinitol shortened the period of the circadian reporter gene Per2-luc in NIH 3T3 cells. These data suggest that the ice plant is a useful functional food and that the ability of inositols to shorten rhythms is a general phenomenon in insects as well as mammals. PMID:26097456

  16. Auditory deprivation modifies biological rhythms in the golden hamster.

    PubMed

    Cutrera, R; Pedemonte, M; Vanini, G; Goldstein, N; Savorini, D; Cardinali, D P; Velluti, R A

    2000-11-01

    To assess to what extent auditory sensory deprivation affects biological rhythmicity, sleep/wakefulness cycle and 24 h rhythm in locomotor activity were examined in golden hamsters after bilateral cochlear lesion. An increase in total sleep time as well as a decrease in wakefulness (W) were associated to an augmented number of W episodes, as well as of slow wave sleep (SWS) and paradoxical sleep (PS) episodes in deaf hamsters. The number of episodes of the three behavioural states and the percent duration of W and SWS increased significantly during the light phase of daily photoperiod only. Lower amplitudes of locomotor activity rhythm and a different phase angle as far as light off were found in deaf hamsters kept either under light-dark photoperiod or in constant darkness. Period of locomotor activity remained unchanged after cochlear lesions. The results indicate that auditory deprivation disturbs photic synchronization of rhythms with little effect on the clock timing mechanism itself. PMID:11116570

  17. Lunar and daily spawning rhythms of Senegal sole Solea senegalensis.

    PubMed

    Oliveira, C; Dinis, M T; Soares, F; Cabrita, E; Pousão-Ferreira, P; Sánchez-Vázquez, F J

    2009-07-01

    A periodicity of 29 days was observed in spawning rhythms in Senegal sole Solea senegalensis, with an acrophase around the last quarter and the new moon. In both spring and autumn, a very marked nocturnal spawning rhythm was registered, with spawning beginning after dusk and the acrophase occurring around 2300 hours. When the photoperiod was artificially extended (from 10L:14D to 14L:10D), S. senegalensis synchronized to the new photoperiod: spawning took place after the new 'dusk', the beginning gradually shifting from 2100 to 2300 hours and the acrophase from 2325 to 0032 hours. Under continuous light conditions, fish sustained rhythmicity for 2 days, with an acrophase at 2249 hours, which suggested the existence of an endogenous pacemaker controlling the daily spawning rhythm. These findings provided new insights for better understanding the reproductive physiology of this species and for optimizing the timing protocols of egg collection and larvae production in S. senegalensis aquaculture. PMID:20738482

  18. Modeling and Validating Chronic Pharmacological Manipulation of Circadian Rhythms

    PubMed Central

    Kim, J K; Forger, D B; Marconi, M; Wood, D; Doran, A; Wager, T; Chang, C; Walton, K M

    2013-01-01

    Circadian rhythms can be entrained by a light-dark (LD) cycle and can also be reset pharmacologically, for example, by the CK1δ/ε inhibitor PF-670462. Here, we determine how these two independent signals affect circadian timekeeping from the molecular to the behavioral level. By developing a systems pharmacology model, we predict and experimentally validate that chronic CK1δ/ε inhibition during the earlier hours of a LD cycle can produce a constant stable delay of rhythm. However, chronic dosing later during the day, or in the presence of longer light intervals, is not predicted to yield an entrained rhythm. We also propose a simple method based on phase response curves (PRCs) that predicts the effects of a LD cycle and chronic dosing of a circadian drug. This work indicates that dosing timing and environmental signals must be carefully considered for accurate pharmacological manipulation of circadian phase. PMID:23863866

  19. Basal forebrain control of wakefulness and cortical rhythms

    PubMed Central

    Anaclet, Christelle; Pedersen, Nigel P.; Ferrari, Loris L.; Venner, Anne; Bass, Caroline E.; Arrigoni, Elda; Fuller, Patrick M.

    2015-01-01

    Wakefulness, along with fast cortical rhythms and associated cognition, depend on the basal forebrain (BF). BF cholinergic cell loss in dementia and the sedative effect of anti-cholinergic drugs have long implicated these neurons as important for cognition and wakefulness. The BF also contains intermingled inhibitory GABAergic and excitatory glutamatergic cell groups whose exact neurobiological roles are unclear. Here we show that genetically targeted chemogenetic activation of BF cholinergic or glutamatergic neurons in behaving mice produced significant effects on state consolidation and/or the electroencephalogram but had no effect on total wake. Similar activation of BF GABAergic neurons produced sustained wakefulness and high-frequency cortical rhythms, whereas chemogenetic inhibition increased sleep. Our findings reveal a major contribution of BF GABAergic neurons to wakefulness and the fast cortical rhythms associated with cognition. These findings may be clinically applicable to manipulations aimed at increasing forebrain activation in dementia and the minimally conscious state. PMID:26524973

  20. Thalamocortical mechanisms for integrating musical tone and rhythm.

    PubMed

    Musacchia, Gabriella; Large, Edward W; Schroeder, Charles E

    2014-02-01

    Studies over several decades have identified many of the neuronal substrates of music perception by pursuing pitch and rhythm perception separately. Here, we address the question of how these mechanisms interact, starting with the observation that the peripheral pathways of the so-called "Core" and "Matrix" thalamocortical system provide the anatomical bases for tone and rhythm channels. We then examine the hypothesis that these specialized inputs integrate acoustic content within rhythm context in auditory cortex using classical types of "driving" and "modulatory" mechanisms. This hypothesis provides a framework for deriving testable predictions about the early stages of music processing. Furthermore, because thalamocortical circuits are shared by speech and music processing, such a model provides concrete implications for how music experience contributes to the development of robust speech encoding mechanisms. PMID:24103509