Search results: Found 4

Listing 1 - 4 of 4
Sort by
Heart Rate Variability: Clinical Applications and Interaction between HRV and Heart Rate

Authors: --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889196524 Year: Pages: 166 DOI: 10.3389/978-2-88919-652-4 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Physiology
Added to DOAB on : 2016-08-16 10:34:25
License:

Loading...
Export citation

Choose an application

Abstract

Over the last decades, assessment of heart rate variability (HRV) has increased in various fields of research. HRV describes changes in heartbeat intervals, which are caused by autonomic neural regulation, i.e. by the interplay of the sympathetic and the parasympathetic nervous systems. The most frequent application of HRV is connected to cardiological issues, most importantly to the monitoring of post-myocardial infarction patients and the prediction of sudden cardiac death. Analysis of HRV is also frequently applied in relation to diabetes, renal failure, neurological and psychiatric conditions, sleep disorders, psychological phenomena such as stress, as well as drug and addiction research including alcohol and smoking. The widespread application of HRV measurements is based on the fact that they are noninvasive, easy to perform, and in general reproducible – if carried out under standardized conditions. However, the amount of parameters to be analysed is still rising. Well-established time domain and frequency domain parameters are discussed controversially when it comes to their physiological interpretation and their psychometric properties like reliability and validity, and the sensitivity to cardiovascular properties of the variety of parameters seems to be a topic for further research. Recently introduced parameters like pNNxx and new dynamic methods such as approximate entropy and detrended fluctuation analysis offer new potentials and warrant standardization. However, HRV is significantly associated with average heart rate (HR) and one can conclude that HRV actually provides information on two quantities, i.e. on HR and its variability. It is hard to determine which of these two plays a principal role in the clinical value of HRV. The association between HRV and HR is not only a physiological phenomenon but also a mathematical one which is due to non-linear (mathematical) relationship between RR interval and HR. If one normalizes HRV to its average RR interval, one may get ‘pure’ variability free from the mathematical bias. Recently, a new modification method of the association between HRV and HR has been developed which enables us to completely remove the HRV dependence on HR (even the physiological one), or conversely enhance this dependence. Such an approach allows us to explore the HR contribution to the clinical significance of HRV, i.e. whether HR or its variability plays a main role in the HRV clinical value. This Research Topic covers recent advances in the application of HRV, methodological issues, basic underlying mechanisms as well as all aspects of the interaction between HRV and HR.

The adrenergic system in cardiovascular physiology and pathophysiology

Author:
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889193981 Year: Pages: 85 DOI: 10.3389/978-2-88919-398-1 Language: English
Publisher: Frontiers Media SA
Subject: Physiology --- Science (General)
Added to DOAB on : 2015-12-10 11:59:06
License:

Loading...
Export citation

Choose an application

Abstract

Cardiovascular diseases pose an enormous clinical challenge, remaining the most common cause of death in the world. ß-adrenoceptors play an important role on cardiac, vascular and/or endothelial function at a cellular level with relevant applications in several cardiovascular diseases, such as heart failure and hypertension. G protein– coupled receptors (GPCRs), including ß-adrenergic receptors, constitute the most ubiquitous superfamily of plasma membrane receptors and represent the single most important type of therapeutic drug target. Sympathetic nervous system hyperactivity, which characterizes several cardiovascular diseases, such as heart failure and hypertension, as well as physiological ageing, has been proved to exert in the long-term detrimental effects in a wide range of cardiovascular diseases. Acutely, sympathetic hyperactivity represents the response to an insult to the myocardium, aiming to compensate for decreased cardiac output. This process involves the activation of beta-adrenergic receptors by catecholamine with consequent heart rate and cardiac contractility increase. However, long-term exposure of the heart to elevated norepinephrine and epinephrine levels, originating from sympathetic nerve endings and chromaffin cells of the adrenal gland, results in further progressive deterioration in cardiac structure and function. At the molecular level, sustained sympathetic nervous system hyperactivity is responsible for several alterations including altered beta-adrenergic receptor signaling and function (down-regulation/ desensitization). Moreover, the detrimental effects of catecholamine affect also the function of different cell types including, but not limited to, endothelial cells, fibroblasts and smooth muscle cells. Thus, the success of beta-blocker therapy is due, at least in part, to the protection of the heart and the vasculature from the noxious effects of augmented catecholamine levels. The research topic aimed to support the progress towards understanding the role of sympathetic nervous system under physiological conditions, and the contribution of its hyperactivity in the pathogenesis and progression of cardiovascular diseases.

The Adrenergic System in Cardiovascular Physiology and Pathophysiology, 2nd Edition

Author:
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889197316 Year: Pages: 78 DOI: 10.3389/978-2-88919-731-6 Language: English
Publisher: Frontiers Media SA
Subject: Physiology --- Science (General)
Added to DOAB on : 2016-04-07 11:22:02
License:

Loading...
Export citation

Choose an application

Abstract

Cardiovascular diseases pose an enormous clinical challenge, remaining the most common cause of death in the world. ß-adrenoceptors play an important role on cardiac, vascular and/or endothelial function at a cellular level with relevant applications in several cardiovascular diseases, such as heart failure and hypertension. G protein– coupled receptors (GPCRs), including ß-adrenergic receptors, constitute the most ubiquitous superfamily of plasma membrane receptors and represent the single most important type of therapeutic drug target. Sympathetic nervous system hyperactivity, which characterizes several cardiovascular diseases, such as heart failure and hypertension, as well as physiological ageing, has been proved to exert in the long-term detrimental effects in a wide range of cardiovascular diseases. Acutely, sympathetic hyperactivity represents the response to an insult to the myocardium, aiming to compensate for decreased cardiac output. This process involves the activation of beta-adrenergic receptors by catecholamine with consequent heart rate and cardiac contractility increase. However, long-term exposure of the heart to elevated norepinephrine and epinephrine levels, originating from sympathetic nerve endings and chromaffin cells of the adrenal gland, results in further progressive deterioration in cardiac structure and function. At the molecular level, sustained sympathetic nervous system hyperactivity is responsible for several alterations including altered beta-adrenergic receptor signaling and function (down-regulation/ desensitization). Moreover, the detrimental effects of catecholamine affect also the function of different cell types including, but not limited to, endothelial cells, fibroblasts and smooth muscle cells. Thus, the success of beta-blocker therapy is due, at least in part, to the protection of the heart and the vasculature from the noxious effects of augmented catecholamine levels. The research topic aimed to support the progress towards understanding the role of sympathetic nervous system under physiological conditions, and the contribution of its hyperactivity in the pathogenesis and progression of cardiovascular diseases.

Second hand smoke and COPD: lessons from animal studies

Authors: --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889193165 Year: Pages: 91 DOI: 10.3389/978-2-88919-316-5 Language: English
Publisher: Frontiers Media SA
Subject: Physiology --- Science (General)
Added to DOAB on : 2016-02-05 17:24:33
License:

Loading...
Export citation

Choose an application

Abstract

Cigarette smoke exposure is the key initiator of chronic inflammation, alveolar destruction, and the loss of alveolar blood vessels that lead to the development of chronic obstructive pulmonary disease (COPD) which is comprised of emphysema and chronic bronchitis. Exposure to secondhand smoke (SHS) is the major risk factor for non-smokers to develop emphysema. While the first-hand smoke is directly inhaled by smokers, passive smoking occurs when non-smokers are involuntary exposed to environmental tobacco smoke also known as second hand smoke (SHS). SHS is a mixture of 2 forms of smoke that come from burning tobacco: side stream smoke (smoke that comes from the end of a lit cigarette, pipe, or cigar) and mainstream smoke (smoke that is exhaled by a smoker). These two types of smoke have basically the same composition, however in SHS many toxic components are more concentrated than in first-hand smoke, therefore more hazardous for people’s health. Several pathological events have been implicated in the development of SHS-induced COPD, but many aspects of this pathology remain poorly understood halting the development of new advanced treatments for this detrimental disease. In this respect we have welcomed leading investigators in the field to share their research findings and provide their thoughts regarding the mechanisms of the SHS exposure-induced immune responses and inflammatory mechanisms of lung destruction in SHS-induced COPD and related comorbidities.

Listing 1 - 4 of 4
Sort by
Narrow your search

Publisher

Frontiers Media SA (4)


License

CC by (4)


Language

english (4)


Year
From To Submit

2015 (4)