Stability of Physiological Functions and Methods of Its Estimation

10.12737/3301 ◽  
2014 ◽  
Vol 21 (1) ◽  
pp. 12-17
Author(s):  
Мезенцева ◽  
Larisa Mezentseva ◽  
Перцов ◽  
S. Pertsov
Keyword(s):  
Heart Rate ◽  
Initial Conditions ◽  
Experimental Models ◽  
Electrical Stability ◽  
Physiological Functions ◽  
Computer Methods ◽  
Heart Rate Dynamics ◽  
Basic Ideas ◽  
Heart Conducting System ◽  
Cardiovascular Functions

Problem of physiological functions stability is the important part of the theoretical physiology. P.K.Anohin´s basic ideas - the theory of functional systems and systemic approach to study of physiological functions have begun the development of theoretical physiology and mathematical modeling in biomedicine. In this paper methodological aspects of using of various biomodels for an estimation of stability of physiological functions are considered. Experimental, genetic, mathematical and computer biomodels are described. Practical techniques of an estimation of stability are illustrated on an example of stability of cardiovascular functions to stressor loads. Examples of different experimental models of stress and methods of estimation of stressor loads influence on cardiac electrical stability are described. Cardiac electrical stability was estimated by thresholds for ventricular fibrillation. Besides experimental, examples of mathematical and computer methods of an estimation of stability of cardiovascular functions to stressor loads are presented. Mathematical model that enables to investigate the stability of heart rate dynamics to stressor loads is based on quantitative characteristics of impulse conduction in heart conducting system. The model describes the phenomena observed at gradual increase of stressor intensity. It was shown the existence of a critical point of transition of heart rate dynamics from linear to chaotic mode. The results show that the greatest stability is notable for the linear regime. For this regime small errors in values of initial conditions can’t sharply change the initial dynamics of RR intervals.

Assessment of Nonlinear Heart Rate Dynamics after Beating-Heart Revascularization

2009 ◽  
Vol 12 (1) ◽  
pp. E10-E16 ◽  
Author(s):  
Jus Ksela ◽  
Piotr Suwalski ◽  
Jurij Matija Kalisnik ◽  
Viktor Avbelj ◽  
Grzegorz Suwalski ◽  
...  
Keyword(s):  
Heart Rate ◽  
Beating Heart ◽  
Nonlinear Heart Rate Dynamics ◽  
Heart Rate Dynamics

Heart Rate Dynamics After Acute Cocaine Administration

1992 ◽  
Vol 19 (3) ◽  
pp. 453-459 ◽  
Author(s):  
Alan Garfinkel ◽  
Sheryl L. Raetz ◽  
Ronald M. Harper
Keyword(s):  
Heart Rate ◽  
Cocaine Administration ◽  
Heart Rate Dynamics

scholarly journals PR interval as a predictor of syncope in tilt-up testing in adolescents and young adults

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Juraj Jug ◽  
Lada Bradić ◽  
Rea Levicki ◽  
Martina Lovrić Benčić
Keyword(s):  
Heart Rate ◽  
Vasovagal Syncope ◽  
True Positive ◽  
Ecg Monitoring ◽  
Interval Prolongation ◽  
Patient History ◽  
Pr Interval ◽  
Heart Rate Dynamics ◽  
Testing Data ◽  
Consciousness Disorder

Abstract Background Syncope, as the most frequent consciousness disorder, is very common in young individuals. The aim of this study was to analyze ECG parameters and clinical properties obtained during tilt-up testing in 12 to 30-year-old subjects. We enrolled a total of 142 patients from our outpatient clinic (39 males, 103 females) with a true positive tilt-up test and analyzed ECG records obtained during tilt-testing. Data were stratified according to the age, gender, and type of syncope. Results PR interval shortening preceding syncope was found in all syncope types, irrespective of the gender. All types of syncope were more frequent in women (72.5%). Mixed syncope type was found to be the most common (47.18%). Male and female subjects differed in initial heart rate (71.56 vs 76.23/min, p=0.05), as well as heart rate dynamics during tilt-up testing. A gender difference was also found in systolic blood pressure (116.92 vs 110.44 mmHg, p<0.01), time to syncope onset (20.77 vs. 16.44 min, p=0.03), and the total number of syncopal episodes in patient history (2.79 vs. 4.62, p<0.05). Subjects with cardioinhibitory syncope had the longest PR interval (average 154.3 ms). PR interval prolongation and loss of variability during tilt-up testing positively correlated with aging (r=0.22, p<0.05). Nodal rhythm was found in 8 patients. Conclusion PR interval shortening on ECG tracings during a tilt-up test can be found in all subtypes of vasovagal syncope, thereby contrasting previous reports that these changes are a hallmark of the cardioinhibitory type of syncope. PR shortening, if observed during ECG monitoring, could be a potential predictor of syncope.

scholarly journals Identification of heart rate dynamics during moderate-to-vigorous treadmill exercise

2015 ◽  
Vol 14 (1) ◽  
Author(s):  
Kenneth J. Hunt ◽  
Simon E. Fankhauser ◽  
Jittima Saengsuwan
Keyword(s):  
Heart Rate ◽  
Treadmill Exercise ◽  
Heart Rate Dynamics

Nonlinear analysis of heart rate dynamics in hyperthyroidism

2007 ◽  
Vol 28 (4) ◽  
pp. 427-437 ◽  
Author(s):  
Jin-Long Chen ◽  
Yin-Jiun Tseng ◽  
Hung-Wen Chiu ◽  
Tzu-Chien Hsiao ◽  
Woei-Chyn Chu
Keyword(s):  
Heart Rate ◽  
Nonlinear Analysis ◽  
Heart Rate Dynamics

Complex and irregular heart rate dynamics in fetuses compromised by maternal anemia as a high-risk pregnancy

2015 ◽  
Vol 43 (6) ◽  
Author(s):  
Young-Sun Park ◽  
Jeong-Kyu Hoh
Keyword(s):  
Heart Rate ◽  
High Risk ◽  
Approximate Entropy ◽  
Risk Groups ◽  
Adverse Outcomes ◽  
Maternal Anemia ◽  
Risk Pregnancy ◽  
Heart Rate Dynamics ◽  
Study Population ◽  
Normal Controls

AbstractTo examine how complex and irregular fetal heart rate (FHR) dynamics differ between fetuses of normal pregnancies and those of pregnancies complicated by maternal anemia (MA), and to place this in the context of high-risk pregnancies.Our study population consisted of 97 pregnant women affected by MA, 118 affected by pregnancy-induced hypertension (PIH), 88 affected by gestational diabetes mellitus (GDM), 53 with preterm premature rupture of membranes (pPROM), and 356 normal pregnancies as controls. We calculated approximate entropy (ApEn), sample entropy (SampEn), and correlation dimension (CD) to quantify irregularity and the chaotic dynamics of each FHR time series.The ApEn in the fetuses of the MA and PIH groups was significantly lower than that of the normal controls (P<0.05). The SampEn was significantly lower in the high-risk groups, except for the pPROM group, than in the normal controls (P<0.05). The CD in the PIH and severe MA groups was significantly lower than that of the normal controls (P<0.05, respectively). In the MA group, the dynamic indices showed a highly significant positive correlation with hemoglobin (Hb) levels (P<0.0001).The decreased complexity and/or irregularity in the FHR from pregnancies with MA may reflect abnormalities in the complex, integrated cardiovascular control. The irregularity and complexity of the FHR increased together with Hb levels in pregnancies with MA. Our data suggest that the integrity of the nervous system in the fetuses compromised by severe MA might result directly in adverse outcomes.

Abstract MP45: Deletion Of The Transient Receptor Vanilloid-1 (TRPV1) Channel In Rats Attenuates 2 Kidney 1 Clip Hypertension

Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Sean D Stocker ◽  
Leon J DeLalio
Keyword(s):  
Heart Rate ◽  
Renovascular Hypertension ◽  
Sensory Nerve ◽  
Experimental Models ◽  
Sensory Nerves ◽  
Male Rats ◽  
Wild Type ◽  
Renal Nerve ◽  
Trpv1 Channels ◽  
Arterial Blood

Renal denervation lowers arterial blood pressure (ABP) in both clinical populations and multiple experimental models of hypertension. This therapeutic effect is partly attributed to the removal of overactive renal sensory nerves that increase sympathetic efferent activity and ABP. Renal sensory nerves highly express TRPV1 channels, and administration of the TRPV1 agonist capsaicin increases renal sensory nerve activity. However, the extent by which TRPV1 channels directly contribute to renal nerve dependent models of hypertension has not been tested. To test this hypothesis, we generated a novel TRPV1 -/- rat using CRISPR/Cas9 and deletion of exon 3. Male and female TRPV1 -/- and wild-type littermates (8-12 weeks) were instrumented with telemetry. At 2 weeks later, renovascular hypertension via renal stenosis was produced by placement of a PTFE cuff (0.16 x 0.22 inches, 1mm long) around the right renal artery. Male TRPV1 -/- and wild-type rats had no differences in baseline mean ABP (99±2 vs 98±3 mmHg, respectively; n=7-9) or heart rate (390±7 vs 400±8 bpm, respectively). Renal stenosis significantly increased mean ABP in both groups; however, mean ABP was significantly lower at Day 28 in male TRPV1 -/- versus wild-type rats (125±8 vs 155±2 mmHg, respectively: P<0.01). Ganglionic blockade with chlorisondamine (2.5mg/kg, sc) at Day 28 produced a smaller fall in mean ABP of male TRPV1 -/- versus wild-type rats (-53±4 vs -86±3 mmHg, respectively; P<0.001). On the other hand, female TRPV1 -/- and wild-type rats had no differences in baseline mean ABP (102±2 vs 104±1 mmHg, respectively; n=6-9) or heart rate (419±8 vs 410±7 bpm, respectively). Renal stenosis significantly increased mean ABP in both groups; however, there were no differences at Day 28 between female TRPV1 -/- versus wild-type rats (117±8 vs 122±6 mmHg, respectively). Moreover, the increase in mean ABP was smaller in females versus males. The ganglionic blocker chlorisondamine produced similar depressor responses in female TRPV1 -/- versus wild-type rats (-64±7 vs -65±7 mmHg, respectively). These findings illustrate a sex difference in renovascular hypertension in rats, but importantly indicate that TRPV1 channels contribute to the established phase of renovascular hypertension in male rats.

Chaotic Heart Rate Dynamics in Isolated Perfused Rat Hearts

1989 ◽  
pp. 215-224 ◽  
Author(s):  
Joseph P. Zbilut ◽  
Gottfried Mayer-Kress ◽  
Paul A. Sobotka ◽  
Michael O’Toole ◽  
John X. Thomas
Keyword(s):  
Heart Rate ◽  
Rat Hearts ◽  
Heart Rate Dynamics ◽  
Perfused Rat Hearts ◽  
Isolated Perfused Rat Hearts

scholarly journals ECG Ambulatory System for Long Term Monitoring of Heart Rate Dynamics

10.5772/20946 ◽  
2011 ◽  
Author(s):  
Agustin Marquez-Espinoza ◽  
Jose G. ◽  
Gabriel Vega-Martinez ◽  
Carlos Alvarado-Serrano
Keyword(s):  
Heart Rate ◽  
Heart Rate Dynamics ◽  
Long Term Monitoring ◽  
Term Monitoring

scholarly journals Analysis of Heart Rate Dynamics Before and During Meditation

2021 ◽  
Vol 17 (05) ◽  
pp. 100
Author(s):  
Mohammad Karimi Moridani ◽  
Tina Habikazemi ◽  
Nahid Khoramabadi
Keyword(s):  
Heart Rate ◽  
Vital Signs ◽  
Normal Subjects ◽  
Support Vector ◽  
Nonlinear Characteristics ◽  
Rate Analysis ◽  
High Tension ◽  
Heart Rate Dynamics ◽  
Heart Rate Analysis ◽  
Sensitivity Specificity

<p>Heart rate is one of the most important vital signs. People usually face high tension in routine life, and if we found an effective method to control the heart rate, it would be very desirable. One of the goals of this paper is to examine changes in heart rate before and during meditation. Another goal is that what impact could have meditation on the human heartbeat.</p><p>To heart rate analysis before and during meditation, available heart rate signals have been used for the Physionet database that contains 10 normal subjects and 8 subjects that meditation practice has been done on them. In this paper, first is paid to extract linear and nonlinear characteristics of heart rate and then is paid to the best combination of features to identify two intervals before and during meditation using MLP and SVM classifiers with the help of sensitivity, specificity and accuracy measurements.</p><p>The achieved results in this paper showed that choosing the best combination of a feature to make a meaningful difference between two intervals before and during meditation includes two-time features (Mean HR, SDNN), a frequency feature ( ), and three nonlinear characteristics   ( ). Also, using the support vector machine had better results than the MLP neural network. The sensitivity, specificity, and accuracy of the mean and standard deviation obtained respectively like 92.73  0.23, 89.05 0.67, 89.97 0.23 by using MLP and respectively like 95.96 0.09, 93.80 0.16, and 94.90 0.14 by using SVM.</p>As a result, using meditation can reduce the stress and anxiety of patients by effects on heart rate, and the treatment process speeds up and have an important role in improving the performance of the system.

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