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Exercise and pregnancy
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
The major hemodynamic response to exercise is redistribution of blood flow away from the visceral organs and toward the working muscles. During exercise, the cardiac output to the brain and heart remains unchanged, while the uterine blood flow is significantly restricted depending on the intensity of the exercise.
Pathophysiological Responses to Endotoxin in Humans
Published in Helmut Brade, Steven M. Opal, Stefanie N. Vogel, David C. Morrison, Endotoxin in Health and Disease, 2020
Anthony F. Suffredini, Naomi P. O’Grady
The cardiovascular response to endotoxin is characterized by an elevated cardiac index and heart rate, decreased mean arterial pressure and systemic vascular resistance, and reversible depression of left ventricular ejection fraction (13). Measurements derived from pulmonary artery catheterization and radionuclide cineangiograms show that myocardial function, compared to normal subjects, is impaired within 6 hours of endotoxin administration and these changes are reversible by 24 hours (13). This pattern of hemodynamic change is qualitatively similar to the hemodynamic response observed in clinical sepsis (13).
Nursing Care of the Patient Requiring Mechanical Circulatory Support
Published in Wayne E. Richenbacher, Mechanical Circulatory Support, 2020
Kelly L. Jones, Carolyn J. Laxson, Sarah C. Seemuth, Sara J. Vance
Begin with a review of circulatory physiology in VAD patients. A generic review of VAD design and function provides the nursing staff with a better understanding of how the blood pump interacts with the patient’s heart. An example illustrating this point is the hemodynamic response to hypovolemia in a patient supported with a VAD versus the response seen in a patient with normal physiology. With hypovolemia the heart rate increases to maintain systemic perfusion. In the patient supported with a VAD, however, hypovolemia is manifest by a decrease in VAD pumping rate. As the VAD pumps a full stroke volume in the automatic mode, the pumping rate slows to allow time for the VAD to fill in the hypovolemic patient.
Subjective cognitive complaints and its associations to response inhibition and neural activation in patients with stress-related exhaustion disorder
Published in Stress, 2023
Andreas Nelson, Hanna Malmberg Gavelin, Micael Andersson, Maria Josefsson, Therese Eskilsson, Lisbeth Slunga Järvholm, Anna Stigsdotter Neely, Carl-Johan Boraxbekk
A general linear model was designed with event regressors for the incongruent and congruent conditions, and for a baseline block consisting of the last 60 s of rest. The regressors were convolved with the hemodynamic response function. The six movement parameters from the realignment procedure were added as regressors of no interest to the model. A high-pass filter of 128 s/0.0078 Hz was applied. A first-level analysis contrasted [Congruent–Rest], [Incongruent-Rest], and [Incongruent–Congruent] for each participant. In order to assess the relationship between the inhibition cost and neural activity, an [Incongruent–Congruent] contrast for all subjects were included in a t-test at the group level, using a FWE corrected p < 0.05 threshold, minimum cluster size 10 voxels. To investigate the relationship between functional brain response and level of burnout and subjective cognitive complaints, respectively, we added the total scores of the SMBQ and the PRMQ as covariates of interest to the model at the group level using an uncorrected threshold of p < 0.001, minimum cluster size 10 voxels. An explicit mask defined by thresholding the grey-matter part of the DARTEL template in MNI space (probability level 0.2) was applied on all group analyses.
Hemodynamic changes in prefrontal cortex following dynamic balance test in sporting and non-sporting population
Published in Hearing, Balance and Communication, 2023
Abhinav Sathe, Shweta Shenoy, Prachi Khandekar Sathe
A differential path length factor was calculated based on the chronological age of the participant. For fNIRS data, the pre-processing was conducted with a sampling rate of 10 Hz [30,31] using open-source software: HOMER2 implemented in MATLAB (Mathworks). All recorded signals were first converted to optical density for processing in HOMER 2 software. Channels with amplitude lower than the baseline were excluded from group processing. Signals were then processed by the principal component analysis method to remove systematic artefacts [32]. The motion artefact threshold of more than 15 standard deviations from the mean was identified and replaced with Spline interpolation based on the preceding and subsequent segment of the signals. Wavelet filtering was used to remove motion-induced sharp spikes [33]. The signals were then band pass filtered with frequencies between 0.02 and 0.5 Hz to remove baseline drift and physiological noises. Finally, these filtered signals were converted to oxy and deoxy-Hb concentration data (µ Mol) using the modified Beer-Lambert law [34]. The block averaging method was used to infer changes in hemodynamic response across the participants. In this study, we considered activation as a significant increase in oxy and a significant decrease in deoxy-Hb, deactivation as a significant decrease in oxy and a significant increase in deoxy-Hb, and increase in blood volume as a significant increase in both oxy Hb and deoxy Hb and decrease in blood volume as a significant decrease in both oxy Hb and deoxy Hb.
Elite female football players’ perception of the impact of their menstrual cycle stages on their football performance. A semi-structured interview-based study
Published in Science and Medicine in Football, 2022
Phoebe Read, Ritan Mehta, Craig Rosenbloom, Elena Jobson, Katrine Okholm Kryger
The complex interplay between ovarian, hypophyseal, and hypothalamic hormones triggers diverse physiological and psychological changes, manifesting as symptoms such as abdominal cramps, bloating, and irritability (Constantini et al. 2005). Research into subsequent physiological impacts found a variety of cardiovascular, haemodynamic, metabolic, and musculoskeletal effects (Constantini et al. 2005), from increased heart rate and haemodynamic response to stress (Tersman et al. 1991), to decreased diastolic blood pressure (Tersman et al. 1991). There are further cyclical changes in body weight, temperature, and metabolism (Janowsky et al. 1973; Stephenson et al. 1982), whilst cyclical variation in oestrogen levels have been linked to strengthened skeletal muscle contractility (Sarwar et al. 1996). These cyclical disparities in human capabilities potentiate major effects on sporting performance (Constantini et al. 2005).