scholarly journals Functional brain–heart interplay extends to the multifractal domain

2021 ◽  
Vol 379 (2212) ◽  
Author(s):  
Vincenzo Catrambone ◽  
Riccardo Barbieri ◽  
Herwig Wendt ◽  
Patrice Abry ◽  
Gaetano Valenza
Keyword(s):  
Process Model ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Nonlinear Functional ◽  
Functional Brain ◽  
Second Order Statistics ◽  
Challenges And Opportunities ◽  
Biosignal Processing ◽  
Non Gaussian ◽  
Maximal Information Coefficient

The study of functional brain–heart interplay has provided meaningful insights in cardiology and neuroscience. Regarding biosignal processing, this interplay involves predominantly neural and heartbeat linear dynamics expressed via time and frequency domain-related features. However, the dynamics of central and autonomous nervous systems show nonlinear and multifractal behaviours, and the extent to which this behaviour influences brain–heart interactions is currently unknown. Here, we report a novel signal processing framework aimed at quantifying nonlinear functional brain–heart interplay in the non-Gaussian and multifractal domains that combines electroencephalography (EEG) and heart rate variability series. This framework relies on a maximal information coefficient analysis between nonlinear multiscale features derived from EEG spectra and from an inhomogeneous point-process model for heartbeat dynamics. Experimental results were gathered from 24 healthy volunteers during a resting state and a cold pressor test, revealing that synchronous changes between brain and heartbeat multifractal spectra occur at higher EEG frequency bands and through nonlinear/complex cardiovascular control. We conclude that significant bodily, sympathovagal changes such as those elicited by cold-pressure stimuli affect the functional brain–heart interplay beyond second-order statistics, thus extending it to multifractal dynamics. These results provide a platform to define novel nervous-system-targeted biomarkers. This article is part of the theme issue ‘Advanced computation in cardiovascular physiology: new challenges and opportunities’.

Repercussões pressóricas do frio local: a crioterapia deve ser administrada com precaução em pacientes hipertensos?

2016 ◽  
Vol 14 (4) ◽  
Author(s):  
Marcelo Coertjens
Keyword(s):  
Cold Pressor Test ◽  
Cold Pressor ◽  
Pressor Test

Introdução: A crioterapia é um recurso que diminui a temperatura corporal local com finalidades terapêuticas. Uma importante repercussão é a vasoconstrição local, que seria o desencadeador de um possível aumento na pressão arterial (PA). Entretanto, não existem trabalhos que comprovem essa suposição. Nossa hipótese é que os resultados das pesquisas de Cold Pressor Test (CPT) avaliando PA acabaram historicamente fundamentando as precauções da crioterapia em relação a pacientes hipertensos. Objetivo: Realizar uma revisão de literatura a respeito das pesquisas que sustentam a precaução da crioterapia em indivíduos hipertensos e verificar sua relação com estudos que utilizaram o CPT. Material e métodos: Trata-se de uma revisão de literatura que utilizou as bases de dados online Medline, Scielo, Lilacs e Google Acadêmico para a realização da pesquisa. Resultado: Apesar de não serem unânimes, diversas pesquisas que utilizaram o CPT encontraram significativos aumentos da atividade nervosa simpática muscular e da PA em normotensos e hipertensos, entretanto não encontramos estudos que tenham comprovado respostas significativas de PA com o uso da crioterapia, principalmente, em hipertensos. Conclusão: Não existem evidências científicas que comprovem a precaução da crioterapia em indivíduos hipertensos. Além disso, os estudos com CPT não são unânimes em relação aos aumentos pressóricos em indivíduos normotensos e hipertensos.Palavras-chave: crioterapia, hemodinâmica, hipertensão, pressão arterial. 

scholarly journals The expanding role of the cold pressor test: a brief history

2021 ◽  
Author(s):  
Guillaume Lamotte ◽  
Christopher J. Boes ◽  
Phillip A. Low ◽  
Elizabeth A. Coon
Keyword(s):  
Cold Pressor Test ◽  
Cold Pressor ◽  
Pressor Test

The tolerance to stretch is linked with endogenous modulation of pain

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Morten Pallisgaard Støve ◽  
Rogerio Pessoto Hirata ◽  
Thorvaldur Skuli Palsson
Keyword(s):  
Range Of Motion ◽  
Pain Sensitivity ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Static Stretch ◽  
Pain Thresholds ◽  
Pressure Pain ◽  
Pressor Test ◽  
Pressure Pain Thresholds ◽  
Exercise Induced

Abstract Objectives The effect of stretching on joint range of motion is well documented, and although sensory perception has significance for changes in the tolerance to stretch following stretching the underlining mechanisms responsible for these changes is insufficiently understood. The aim of this study was to examine the influence of endogenous pain inhibitory mechanisms on stretch tolerance and to investigate the relationship between range of motion and changes in pain sensitivity. Methods Nineteen healthy males participated in this randomized, repeated-measures crossover study, conducted on 2 separate days. Knee extension range of motion, passive resistive torque, and pressure pain thresholds were recorded before, after, and 10 min after each of four experimental conditions; (i) Exercise-induced hypoalgesia, (ii) two bouts of static stretching, (iii) resting, and (iv) a remote, painful stimulus induced by the cold pressor test. Results Exercise-induced hypoalgesia and cold pressor test caused an increase in range of motion (p<0.034) and pressure pain thresholds (p<0.027). Moderate correlations in pressure pain thresholds were found between exercise-induced hypoalgesia and static stretch (Rho>0.507, p=0.01) and exercise-induced hypoalgesia and the cold pressor test (Rho=0.562, p=0.01). A weak correlation in pressure pain thresholds and changes in range of motion were found following the cold pressor test (Rho=0.460, p=0.047). However, a potential carryover hypoalgesic effect may have affected the results of the static stretch. Conclusions These results suggest that stretch tolerance may be linked with endogenous modulation of pain. Present results suggest, that stretch tolerance may merely be a marker for pain sensitivity which may have clinical significance given that stretching is often prescribed in the rehabilitation of different musculoskeletal pain conditions where reduced endogenous pain inhibition is frequently seen.

Exploring the effects of oily fish consumption on measures of acute and long-term stress in healthy 8-9-year-old children: The FiSK Junior randomized trial

2020 ◽  
pp. 1-26
Author(s):  
Marie N Teisen ◽  
Stine Vuholm ◽  
Jesper M Rantanen ◽  
Jeppe H Christensen ◽  
Camilla T Damsgaard ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Fish Consumption ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Heart Beat ◽  
Autonomic Response ◽  
Hair Cortisol ◽  
Oily Fish ◽  
Fish Group

Abstract Long-chain n-3 PUFA (n-3 LCPUFA) have been shown to reduce blood pressure, heart rate and vagal tone, but potential stress-mitigating effects of n-3 LCPUFA are not well investigated. We aim to explore the effects of oily fish consumption on long-term stress and the stress response in schoolchildren. Healthy 8-9-year-old children were randomized to receive ~300 g/week of oily fish or poultry for 12 ± 2 weeks. At baseline and endpoint, we measured erythrocyte n-3 LCPUFA, hair cortisol and the response to a 1-min cold pressor test (CPT) on saliva cortisol, blood pressure, and continuous electrocardiogram recordings. Of the 199 randomized children, 197 completed the trial. Hair cortisol did not differ between the groups, but a sex-interaction was indicated (Psex*group = 0.074, difference between means -0.9 (95% CI: -2.9,1.0) ng/g and 0.7 (-0.2,1.6) ng/g in boys and girls, respectively). The children in the fish group tended to be less prone to terminate CPT prematurely (OR 0.20 [0.02,1.04]). The mean heart beat interval during CPT was 18.2 (0.3,36.6) ms longer and the high frequency power increased (159 (29,289) ms2) in the fish versus the poultry group. The cardiac autonomic response in the 10 min following CPT was characterized by a sympathetic peak followed by a parasympathetic peak, which was most pronounced in the fish group. This exploratory study does not support a strong effect of oily fish consumption on stress, but indicates that oily fish consumption may increase vagal cardiac tone during the physiological response to CPT. These results warrant further investigation.

scholarly journals Contactless analysis of heart rate variability during cold pressor test using radar interferometry and bidirectional LSTM networks

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kilin Shi ◽  
Tobias Steigleder ◽  
Sven Schellenberger ◽  
Fabian Michler ◽  
Anke Malessa ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Dynamic Change ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Contactless Measurement ◽  
Pressor Test ◽  
Skin Contact ◽  
Bidirectional Lstm ◽  
Lstm Network

AbstractContactless measurement of heart rate variability (HRV), which reflects changes of the autonomic nervous system (ANS) and provides crucial information on the health status of a person, would provide great benefits for both patients and doctors during prevention and aftercare. However, gold standard devices to record the HRV, such as the electrocardiograph, have the common disadvantage that they need permanent skin contact with the patient. Being connected to a monitoring device by cable reduces the mobility, comfort, and compliance by patients. Here, we present a contactless approach using a 24 GHz Six-Port-based radar system and an LSTM network for radar heart sound segmentation. The best scores are obtained using a two-layer bidirectional LSTM architecture. To verify the performance of the proposed system not only in a static measurement scenario but also during a dynamic change of HRV parameters, a stimulation of the ANS through a cold pressor test is integrated in the study design. A total of 638 minutes of data is gathered from 25 test subjects and is analysed extensively. High F-scores of over 95% are achieved for heartbeat detection. HRV indices such as HF norm are extracted with relative errors around 5%. Our proposed approach is capable to perform contactless and convenient HRV monitoring and is therefore suitable for long-term recordings in clinical environments and home-care scenarios.

scholarly journals Effect of short-term smoking & L-arginine on coronary endothelial function assessed by cardiac magnetic resonance cold pressor testing: a pilot study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Andreas M. Weng ◽  
Herbert Köstler ◽  
Thorsten A. Bley ◽  
Christian O. Ritter
Keyword(s):  
Magnetic Resonance ◽  
Imaging Techniques ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Short Term ◽  
Pressor Test ◽  
Coronary Vasomotion ◽  
Short And Long Term ◽  
Coronary Endothelium

Abstract Background The effect of smoking on coronary vasomotion has been investigated in the past with various imaging techniques in both short- and long-term smokers. Additionally, coronary vasomotion has been shown to be normalized in long-term smokers by L-Arginine acting as a substrate for NO synthase, revealing the coronary endothelium as the major site of abnormal vasomotor response. Aim of the prospective cohort study was to investigate coronary vasomotion of young healthy short-term smokers via magnetic resonance cold pressor test with and without the administration of L-Arginine and compare obtained results with the ones from nonsmokers. Methods Myocardial blood flow (MBF) was quantified with first-pass perfusion MRI on a 1.5 T scanner in healthy short-term smokers (N = 10, age: 25.0 ± 2.8 years, 5.0 ± 2.9 pack years) and nonsmokers (N = 10, age: 34.3 ± 13.6) both at rest and during cold pressor test (CPT). Smokers underwent an additional examination after administration of L-Arginine within a median of 7 days of the naïve examination. Results MBF at rest turned out to be 0.77 ± 0.30 (smokers with no L-Arginine; mean ± standard deviation), 0.66 ± 0.21 (smokers L-Arginine) and 0.84 ± 0.08 (nonsmokers). Values under CPT were 1.21 ± 0.42 (smokers no L-Arginine), 1.09 ± 0.35 (smokers L-Arginine) and 1.63 ± 0.33 (nonsmokers). In all groups, MBF was significantly increased under CPT compared to the corresponding rest examination (p < 0.05 in all cases). Additionally, MBF under CPT was significantly different between the smokers and the nonsmokers (p = 0.002). MBF at rest was significantly different between the smokers when L-Arginine was given and the nonsmokers (p = 0.035). Conclusion Short-term smokers showed a reduced response to cold both with and without the administration of L-Arginine. However, absolute MBF values under CPT were lower compared to nonsmokers independently of L-Arginine administration.

Variability of the haemodynamic responses to laboratory tests employed in assessment of neural cardiovascular regulation in man

1985 ◽  
Vol 69 (5) ◽  
pp. 533-540 ◽  
Author(s):  
Gianfranco Parati ◽  
Guido Pomidossi ◽  
Agustin Ramirez ◽  
Bruno Cesana ◽  
Giuseppe Mancia
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Test Performance ◽  
Blood Pressure Response ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Cardiovascular Regulation ◽  
Pressor Test ◽  
Carotid Baroreceptor ◽  
Baroreceptor Stimulation

1. In man evaluation of neural cardiovascular regulation makes use of a variety of tests which address the excitatory and reflex inhibitory neural influences that control circulation. Because interpretation of these tests is largely based on the magnitude of the elicited haemodynamic responses, their reproducibility in any given subject is critical. 2. In 39 subjects with continuous blood pressure (intra-arterial catheter) and heart rate monitoring we measured (i) the blood pressure and heart rate rises during hand-grip and cold-pressor test, (ii) the heart rate changes occurring during baroreceptor stimulation and deactivation by injection of phenylephrine and trinitroglycerine, and (iii) the heart rate and blood pressure changes occurring with alteration in carotid baroreceptor activity by a neck chamber. Each test was carefully standardized and performed at 30 min intervals for a total of six times in each subject. 3. The results showed that the responses to any test were clearly different from one another and that this occurred in all subjects studied. For the group as a whole the average response variability (coefficient of variation) ranged from 10.2% for the blood pressure response to carotid baroreceptor stimulation to 44.2% for the heart rate response to cold-pressor test. The variability of the responses was not related to basal blood pressure or heart rate, nor to the temporal sequence of the test performance. 4. Thus tests employed for studying neural cardiovascular control in man produce responses whose reproducibility is limited. This phenomenon may make it more difficult to define the response magnitude typical of each subject, as well as its comparison in different conditions and diseases.

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