We know surprisingly little on how heartbeat-evoked responses (HERs) vary with cardiac parameters. Here, we measured both stroke volume, or volume of blood ejected at each heartbeat, with impedance cardiography, and HER amplitude with magneto-encephalography, in 21 male and female participants at rest with eyes open. We observed that HER co-fluctuates with stroke volume on a beat-to-beat basis, but only when no correction for cardiac artifact was performed. This highlights the importance of an ICA correction tailored to the cardiac artifact. We also observed that easy-to-measure cardiac parameters (interbeat intervals, ECG amplitude) are sensitive to stroke volume fluctuations and can be used as proxies when stroke volume measurements are not available. Finally, interindividual differences in stroke volume were reflected in MEG data, but whether this effect is locked to heartbeats is unclear. Altogether, our results question assumptions on the link between stroke volume and HERs.
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http://dx.doi.org/10.1016/j.biopsycho.2021.108165 | DOI Listing |
Chin J Integr Med
January 2025
Department of Ultrasound in Medicine, the Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310009, China.
Objective: To evaluate the therapeutic effects of Kuanxiong Aerosol (KXA) on ischemic stroke with reperfusion and elucidate the underlying pharmacological mechanisms.
Methods: In vivo pharmacological effects on ischemic stroke with reperfusion was evaluated using the transient middle cerebral artery occlusion (t-MCAO) mice model. To evaluate short-term outcome, 30 mice were randomly divided into vehicle group (n=15) and KXA group (n=15).
Am J Physiol Heart Circ Physiol
January 2025
Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.
Increased blood pressure upon standing is considered a cardiovascular risk factor. We investigated the reproducibility of changes in aortic blood pressure, heart rate, stroke volume, cardiac output, and systemic vascular resistance during three passive head-up tilts (HUT) in 223 participants without cardiovascular medications (mean age 46 years, BMI 28 kg/m2, 54% male). Median time gap between the first and the second HUT was 9 weeks and the second and the third HUT 4 weeks.
View Article and Find Full Text PDFJ Exp Biol
January 2025
Hannover Medical School, Institute of Functional and Applied Anatomy, 30625 Hanover, Germany.
Small mammals have a higher heart rate and, relative to body mass (Mb), a higher metabolic rate than large mammals. In contrast, heart weight and stroke volume scale linearly with Mb. With mitochondria filling approximately 50% of a shrew cardiomyocyte - space unavailable for myofibrils - it is unclear how small mammals generate enough contractile force to pump blood into circulation.
View Article and Find Full Text PDFHum Brain Mapp
January 2025
Department of Psychology, Concordia University, Montreal, Quebec, Canada.
The cortex and cerebellum are densely connected through reciprocal input/output projections that form segregated circuits. These circuits are shown to differentially connect anterior lobules of the cerebellum to sensorimotor regions, and lobules Crus I and II to prefrontal regions. This differential connectivity pattern leads to the hypothesis that individual differences in structure should be related, especially for connected regions.
View Article and Find Full Text PDFBr J Anaesth
January 2025
Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Outcomes Research Consortium, Cleveland, OH, USA. Electronic address:
Background: Hypotension is associated with organ injury and death in surgical and critically ill patients. In clinical practice, treating hypotension remains challenging because it can be caused by various underlying haemodynamic alterations. We aimed to identify and independently validate endotypes of hypotension in big datasets of surgical and critically ill patients using unsupervised deep learning.
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