Background: Heart transplantation (HTx) surgically transects all connections to the heart, including the autonomic nerves. We prospectively examined signs, timing and consequences of early sympathetic and parasympathetic sinoatrial reinnervation, as well as explored indirect evidence of afferent cardiopulmonary reinnervation.
Methods: Fifty HTx recipients were assessed at 2.5, 6, and 12 mo after HTx. For comparison, 50 healthy controls were examined once. Continuous, noninvasive recordings of hemodynamic variables and heart rate variability indices were performed at supine rest, 0.2 Hz controlled breathing, 60° head-up-tilt, during the Valsalva maneuver and during handgrip isometric exercise.
Results: In HTx recipients, supine low-frequency heart rate variability gradually increased; supine high-frequency variability did not change; heart rate variability indices during controlled breathing remained unaltered; heart rate responses during tilt and isometric exercise gradually increased; the tachycardia response during Valsalva maneuver increased, while the bradycardia response remained unchanged; and indices of baroreflex sensitivity improved. Responses remained low compared to healthy controls. A negative correlation between indices of preload and heart rate response during head-up tilt emerged at 12 mo.
Conclusions: Results suggest that sympathetic reinnervation of the sinoatrial node starts within 6 mo after HTx and strengthens during the first year. No evidence of early parasympathetic reinnervation was found. Indirect signs of afferent reinnervation of cardiopulmonary low-pressure baroreceptors emerged at 12 mo. Better sympathetic sinoatrial control improved heart rate responsiveness to orthostatic challenge and isometric exercise, as well as heart rate buffering of blood pressure fluctuations.
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http://dx.doi.org/10.1097/TP.0000000000003580 | DOI Listing |
Alzheimers Dement
December 2024
Federal University of Technology Akure, Ondo State, Akure, Nigeria.
Background: The effect of high consumption of psychoactive substances of codeine (CDE), tramadol (TMD), and Cannabis sativa (CNB) as concoction has been associated with altered brain cognitive and neurochemical functions. However, the understanding of the complex mechanism behind the intake of Cannabis sativa co-administration with tramadol and codeine on both cardiac and brain function, neurotransmitters, purinergic, and antioxidant enzymes activities in the brain and heart of rats remains unreported.
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Alzheimers Dement
December 2024
University of Kansas Alzheimer's Disease Research Center, Fairway, KS, USA.
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December 2024
Dementia Research Centre, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom.
Background: Responses to individualized music in people living with dementia can be indicated by both verbal and non-verbal cues. Evidence suggests that elevated pupil dilation responses to familiar vs. unfamiliar music are preserved in people living with typical Alzheimer's disease (tAD), and to an extent in people with its atypical 'visual' variant (Posterior Cortical Atrophy; PCA) (Brotherhood et al.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
UK Dementia Research Institute, Care Research and Technology Centre, Imperial College London and the University of Surrey, Guildford, United Kingdom.
Background: Changes in sleep patterns are common in Alzheimer's disease and impact the quality of life of both people living with Alzheimer's (PLWA) and their caregivers. Longitudinal recordings and assessment of night-to-night variations in sleep and physiology can improve our understanding of how sleep influences clinical outcomes and caregiver wellbeing.
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Alzheimers Dement
December 2024
Sri Sivasubramaniya Nadar College Of Engineering, Chennai, Tamil Nadu, India.
Background: Sleep patterns and disruptions may associate with increased dementia risk and contribute to its progression and cognitive decline. Understanding the complexity of the sleep-dementia relationship is crucial for developing interventions that may delay cognitive decline and enhance the well-being of individuals with dementia. This study seeks to explore how the sleeping patterns of patients with dementia impact them and aims to provide insights to help improve the sleep patterns of individuals affected by dementia.
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