Sudden Cardiac Death from the Perspective of Nonlinear Dynamics.

This study models the hemodynamics, consisting of heart rate, SNA, and blood pressure (BP), by modifying a known chaotic electrical circuit, the Chua circuit. A V-trough of the SNA appears when the resistive element between the SNA and BP in the circuit is increased, which corresponds to the impaired regulation of BP by the SNA. This finding is consistent with an acknowledged finding that a depressed baroreflex (a reflex of the BP by SNA) may trigger a lethal arrhythmia. This study indicates that a V-trough of the SNA is a possible precursor of sudden cardiac death on the basis of experimental and clinical findings as well as mathematical modeling. PMID: 29540640 [PubMed - in process]
Source: Journal of Nippon Medical School - Category: Universities & Medical Training Authors: Tags: J Nippon Med Sch Source Type: research

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Abstract Bullying and peer victimization are stressful experiences for youth, and are associated with increased risk for psychopathology. Physiological differences in the body's stress response system may help us to understand vulnerability for depressive symptoms among youth involved with bullying. The current study examined both sympathetic and parasympathetic activity using skin conductance (SCL) and respiratory sinus arrhythmia (RSA) at a neutral baseline and during Cyberball, a stressful social exclusion paradigm. Participants consisted of 175 youth in grades 6-11 (mean age 13.6 years, 51% girls). Multil...
Source: Journal of Abnormal Child Psychology - Category: Psychiatry & Psychology Authors: Tags: J Abnorm Child Psychol Source Type: research
Conclusions: Magnesium sulfate is an important adjuvant drug in the practice of anesthesia, with several clinical effects and a low incidence of adverse events when used at recommended doses. Introduction Magnesium is the fourth most common ion in the body, and it participates in several cellular processes, including protein synthesis, neuromuscular function and stability of nucleic acid, as well as regulating other electrolytes such as calcium and sodium. Magnesium acts as a cofactor in protein synthesis, neuromuscular function and stability and the function of nucleic acids. It is a component of adenosine 5-triph...
Source: Frontiers in Pharmacology - Category: Drugs & Pharmacology Source Type: research
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Source: Frontiers in Endocrinology - Category: Endocrinology Source Type: research
Sara AlMarabeh, Mohammed H. Abdulla and Ken D. O'Halloran* Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland Renal sensory nerves are important in the regulation of body fluid and electrolyte homeostasis, and blood pressure. Activation of renal mechanoreceptor afferents triggers a negative feedback reno-renal reflex that leads to the inhibition of sympathetic nervous outflow. Conversely, activation of renal chemoreceptor afferents elicits reflex sympathoexcitation. Dysregulation of reno-renal reflexes by suppression of the inhibitory refle...
Source: Frontiers in Physiology - Category: Physiology Source Type: research
A 30-something y.o. male with PMH significant for anxiety, asthma, and alcohol use disorder presented with chest pain x 1 week.  Patient thinks he has an asthma flare, with wheezing. He subsequently developed fevers and chills, and then left-sided chest pain associated with a cough. His breathing and infectious sx then improved. Today, however, he developed constant chest pain radiating into left arm around 1345. He states the pain is improving now. He had associated " swimmy, head rush, " which is no longer present. He denies associated shortness of breath, sweating, numbness, tingling. Onset of pain was wh...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs
AbstractPurpose of ReviewObstructive sleep apnea (OSA) is a systemic disease that is due to a narrow upper airway that collapses and obstructs during sleep, which results in frequent nocturnal hypoxemia, sympathetic overdrive, tachycardia, nocturnal hypertension, and oxidative metabolic stress. Symptoms include unrefreshed sleep, daytime tiredness, loss of memory, irritability, lack of concentration, poor work productivity, poor quality of life (QOL), mood swings, and even depression. This upper airway disorder can lead to systemic diseases such as hypertension, cardiovascular events, myocardial infarct, and fatal arrhythm...
Source: Current Otorhinolaryngology Reports - Category: ENT & OMF Source Type: research
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Source: Menopause - Category: OBGYN Tags: Brief Report Source Type: research
Neurobiological processes are highlighted in animal and theoretical models of the development of depression, but there is mixed empirical evidence about associations between stress physiology and depressive symptoms. Adolescence has been highlighted as a period during which coordination across physiological stress response systems may be particularly important. However, most studies have focused on depressive symptoms and physiological reactivity in isolated systems. The goal of this study was to examine associations of hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS; i.e., sympathetic and paras...
Source: Developmental Psychology - Category: Child Development Source Type: research
Written by Pendell Meyers, with edits by Steve SmithI received a text message with no clinical information other than the following ECG, with the question " Is this Wellens? No prior ECG available. "What do you think?I responded that this ECG represented benign T-wave inversion (BTWI), not Wellens. I asked for more history.It turns out this was a 25 year old male with no past medical history presenting after he was found " passed out " or laying down on the floor of the nursing home facility where he works. He was reported to be intermittently answering questions and seeming " not himself. " F...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs
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Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs
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