Heart rate variability (HRV) is considered a reliable reflection of the many physiological factors modulating the normal rhythm of the heart. It reflects autonomic nervous system (ANS) function, and as such, it is used in numerous fields of medicine. Written by experts in the field, this book provides a comprehensive overview of HRV. The first section is dedicated to technical themes related to monitoring and the variables recorded. The second section highlights use of HRV in hypothermia. Finally, the third section covers general aspects of HRV application.

Unique case-based guide to generating diagnostic possibilities based on the patients' symptoms. Invaluable for psychiatrists and neurologists.

This book presents the concepts underlying the measurement of parasympathetic and sympathetic (P&S) activity in the autonomic nervous system and the application of these measurements in the development of therapeutic guidelines for treating dysfunctions in these processes. It provides an overview of the anatomy, physiology, and biochemistry of the autonomic nervous system; details general clinical applications of P&S monitoring that are independent of specialty or disease; presents the pathophysiology of P&S dysfunction in specific disorders, expected test results, therapeutic options, and expected outcomes; and includes case studies and longitudinal studies that demonstrate the major concepts for the common diseases for which P&S monitoring is recommended. Clinical Autonomic Dysfunction enables clinicians to improve patient outcomes by identifying and treating clinical problems related to autonomic nervous system disorders.

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.

Clinical Neurophysiology, Third Edition will continue the tradition of the previous two volumes by providing a didactic, yet accessible, presentation of electrophysiology in three sections that is of use to both the clinician and the researcher. The first section describes the analysis of electrophysiological waveforms. Section two describes the various methods and techniques of electrophysiological testing. The third section, although short in appearance, has recommendations of symptom complexes and disease entities using electroencephalography, evoked potentials, and nerve conduction studies.

The purpose of this book is to present a focused approach to the pathophysiology, diagnosis, and management of the most common autonomic disorders that may present to the clinical neurologist. Autonomic Neurology is divided into 3 sections. The first section includes 5 chapters reviewing the anatomical and biochemical mechanisms of central and peripheral nervous system control of autonomic function, principles of autonomic pharmacology, and a clinical and laboratory approach to the diagnosis of autonomic disorders. The second section focuses on the pathophysiology and management of orthostatic hypotension, postural tachycardia, baroreflex failure; syncope, disorders of sweating, neurogenic bladder and sexual dysfunction, gastrointestinal dysmotility, and autonomic hyperactivity. The final section is devoted to specific autonomic disorders, including central neurodegenerative disorders; common peripheral neuropathies with prominent autonomic failure; painful small fiber neuropathies; autoimmune autonomic ganglionopathies and neuropathies; focal brain disorders; focal spinal cord disorders; and chronic pain disorders with autonomic manifestations. This book is the product of the extensive experience of its contributors in the evaluation and management of the many patients with autonomic symptoms who are referred for neurologic consultation at Mayo Clinic in Rochester, Minnesota. Autonomic Neurology focuses on clinical scenarios and presentation of clinical cases and includes several figures showing the results of normal and abnormal autonomic testing in typical conditions. Its abundance of tables summarizing the differential diagnosis, testing, and management of autonomic disorders also help set this book apart from other books focused on the autonomic nervous system.