Changes in cardiorespiratory coupling as index of mental stress - A new method to quantify evoked cardiac response

1997 ◽  
Vol 103 (1) ◽  
pp. 219
Author(s):  
A Gonschorek
Keyword(s):  
Mental Stress ◽  
New Method ◽  
Cardiac Response ◽  
Cardiorespiratory Coupling

scholarly journals Blunted Autonomic Reactivity to Mental Stress in Depression Quantified by Nonlinear Cardiorespiratory Coupling Indices

2020 ◽  
Author(s):  
Spyridon Kontaxis ◽  
Pablo Laguna ◽  
Esther García Pages ◽  
Mar Posadas-de Miguel ◽  
Sara Siddi ◽  
...  
Keyword(s):  
Mental Stress ◽  
Autonomic Reactivity ◽  
Cardiorespiratory Coupling

scholarly journals Cardiorespiratory Dynamic Response to Mental Stress: A Multivariate Time-Frequency Analysis

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Devy Widjaja ◽  
Michele Orini ◽  
Elke Vlemincx ◽  
Sabine Van Huffel
Keyword(s):  
Dynamic Response ◽  
Mental Stress ◽  
Mental Arithmetic ◽  
Autonomic Response ◽  
Vagal Activity ◽  
Simulation Studies ◽  
Time Frequency ◽  
Rr Interval ◽  
Time Varying Parameters ◽  
Cardiorespiratory Coupling

Mental stress is a growing problem in our society. In order to deal with this, it is important to understand the underlying stress mechanisms. In this study, we aim to determine how the cardiorespiratory interactions are affected by mental arithmetic stress and attention. We conduct cross time-frequency (TF) analyses to assess the cardiorespiratory coupling. In addition, we introduce partial TF spectra to separate variations in the RR interval series that are linearly related to respiration from RR interval variations (RRV) that are not related to respiration. The performance of partial spectra is evaluated in two simulation studies. Time-varying parameters, such as instantaneous powers and frequencies, are derived from the computed spectra. Statistical analysis is carried out continuously in time to evaluate the dynamic response to mental stress and attention. The results show an increased heart and respiratory rate during stress and attention, compared to a resting condition. Also a fast reduction in vagal activity is noted. The partial TF analysis reveals a faster reduction of RRV power related to (3 s) than unrelated to (30 s) respiration, demonstrating that the autonomic response to mental stress is driven by mechanisms characterized by different temporal scales.

scholarly journals Cardiorespiratory coupling in cetaceans; a physiological strategy to improve gas exchange?

2020 ◽  
Vol 223 (17) ◽  
pp. jeb226365 ◽  
Author(s):  
Andreas Fahlman ◽  
Stefan Miedler ◽  
Luis Marti-Bonmati ◽  
Diana Ferrero Fernandez ◽  
Paola Muñoz Caballero ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Killer Whale ◽  
Bottlenose Dolphins ◽  
Beluga Whale ◽  
Cardiac Response ◽  
Delphinapterus Leucas ◽  
Pilot Whale ◽  
Terrestrial Mammals ◽  
False Killer Whale ◽  
Cardiorespiratory Coupling

ABSTRACTIn the current study we used transthoracic echocardiography to measure stroke volume (SV), heart rate (fH) and cardiac output (CO) in adult bottlenose dolphins (Tursiops truncatus), a male beluga whale calf [Delphinapterus leucas, body mass (Mb) range: 151–175 kg] and an adult female false killer whale (Pseudorca crassidens, estimated Mb: 500–550 kg) housed in managed care. We also recorded continuous electrocardiogram (ECG) in the beluga whale, bottlenose dolphin, false killer whale, killer whale (Orcinus orca) and pilot whale (Globicephala macrorhynchus) to evaluate cardiorespiratory coupling while breathing spontaneously under voluntary control. The results show that cetaceans have a strong respiratory sinus arrythmia (RSA), during which both fH and SV vary within the interbreath interval, making average values dependent on the breathing frequency (fR). The RSA-corrected fH was lower for all cetaceans compared with that of similarly sized terrestrial mammals breathing continuously. As compared with terrestrial mammals, the RSA-corrected SV and CO were either lower or the same for the dolphin and false killer whale, while both were elevated in the beluga whale. When plotting fR against fH for an inactive mammal, cetaceans had a greater cardiac response to changes in fR as compared with terrestrial mammals. We propose that these data indicate an important coupling between respiration and cardiac function that enhances gas exchange, and that this RSA is important to maximize gas exchange during surface intervals, similar to that reported in the elephant seal.

Selective Sampling and Orientation of Non-Homogeneous Tissues

1968 ◽  
Vol 26 ◽  
pp. 98-99
Author(s):  
C. C. Clawson ◽  
L. W. Anderson ◽  
R. A. Good
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Random Sampling ◽  
New Method ◽  
Microscope Examination ◽  
Small Areas ◽  
Selective Sampling ◽  
Large Numbers ◽  
Specific Orientation

Investigations which require electron microscope examination of a few specific areas of non-homogeneous tissues make random sampling of small blocks an inefficient and unrewarding procedure. Therefore, several investigators have devised methods which allow obtaining sample blocks for electron microscopy from region of tissue previously identified by light microscopy of present here techniques which make possible: 1) sampling tissue for electron microscopy from selected areas previously identified by light microscopy of relatively large pieces of tissue; 2) dehydration and embedding large numbers of individually identified blocks while keeping each one separate; 3) a new method of maintaining specific orientation of blocks during embedding; 4) special light microscopic staining or fluorescent procedures and electron microscopy on immediately adjacent small areas of tissue.

A new method for the determination of nitrates

1960 ◽  
Vol 23 ◽  
pp. 227-232 ◽  
Author(s):  
P WEST ◽  
G LYLES
Keyword(s):  
New Method
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