1
|
De Cannière H, Smeets CJP, Schoutteten M, Varon C, Van Hoof C, Van Huffel S, Groenendaal W, Vandervoort P. Using Biosensors and Digital Biomarkers to Assess Response to Cardiac Rehabilitation: Observational Study. J Med Internet Res 2020; 22:e17326. [PMID: 32432552 PMCID: PMC7270861 DOI: 10.2196/17326] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 03/06/2020] [Accepted: 04/10/2020] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Cardiac rehabilitation (CR) is known for its beneficial effects on functional capacity and is a key component within current cardiovascular disease management strategies. In addition, a larger increase in functional capacity is accompanied by better clinical outcomes. However, not all patients respond in a similar way to CR. Therefore, a patient-tailored approach to CR could open up the possibility to achieve an optimal increase in functional capacity in every patient. Before treatment can be optimized, the differences in response of patients in terms of cardiac adaptation to exercise should first be understood. In addition, digital biomarkers to steer CR need to be identified. OBJECTIVE The aim of the study was to investigate the difference in cardiac response between patients characterized by a clear improvement in functional capacity and patients showing only a minor improvement following CR therapy. METHODS A total of 129 patients in CR performed a 6-minute walking test (6MWT) at baseline and during four consecutive short-term follow-up tests while being equipped with a wearable electrocardiogram (ECG) device. The 6MWTs were used to evaluate functional capacity. Patients were divided into high- and low-response groups, based on the improvement in functional capacity during the CR program. Commonly used heart rate parameters and cardiac digital biomarkers representative of the heart rate behavior during the 6MWT and their evolution over time were investigated. RESULTS All participating patients improved in functional capacity throughout the CR program (P<.001). The heart rate parameters, which are commonly used in practice, evolved differently for both groups throughout CR. The peak heart rate (HRpeak) from patients in the high-response group increased significantly throughout CR, while no change was observed in the low-response group (F4,92=8.321, P<.001). Similar results were obtained for the recovery heart rate (HRrec) values, which increased significantly over time during every minute of recuperation, for the high-response group (HRrec1: P<.001, HRrec2: P<.001, HRrec3: P<.001, HRrec4: P<.001, and HRrec5: P=.02). The other digital biomarkers showed that the evolution of heart rate behavior during a standardized activity test differed throughout CR between both groups. These digital biomarkers, derived from the continuous measurements, contribute to more in-depth insight into the progression of patients' cardiac responses. CONCLUSIONS This study showed that when using wearable sensor technology, the differences in response of patients to CR can be characterized by means of commonly used heart rate parameters and digital biomarkers that are representative of cardiac response to exercise. These digital biomarkers, derived by innovative analysis techniques, allow for more in-depth insights into the cardiac response of cardiac patients during standardized activity. These results open up the possibility to optimized and more patient-tailored treatment strategies and to potentially improve CR outcome.
Collapse
Affiliation(s)
- Hélène De Cannière
- Mobile Health Unit, Limburg Clinical Research Center (LCRC), Faculty of Medicine and Life Sciences, Hasselt University (UHasselt), Diepenbeek, Belgium
- Department of Future Health, Ziekenhuis Oost-Limburg, Genk, Belgium
| | - Christophe J P Smeets
- Mobile Health Unit, Limburg Clinical Research Center (LCRC), Faculty of Medicine and Life Sciences, Hasselt University (UHasselt), Diepenbeek, Belgium
- Department of Future Health, Ziekenhuis Oost-Limburg, Genk, Belgium
- Holst Centre, imec the Netherlands, Eindhoven, Netherlands
| | - Melanie Schoutteten
- Mobile Health Unit, Limburg Clinical Research Center (LCRC), Faculty of Medicine and Life Sciences, Hasselt University (UHasselt), Diepenbeek, Belgium
- Department of Future Health, Ziekenhuis Oost-Limburg, Genk, Belgium
| | - Carolina Varon
- Center for Dynamical Systems, Signal Processing and Data Analytics (STADIUS), Department of Electrical Engineering (ESAT), KU (Katholieke Universiteit) Leuven, Leuven, Belgium
- Circuits and Systems (CAS), Department of Microelectronics, Delft University of Technology (TU Delft), Delft, Netherlands
| | - Chris Van Hoof
- Center for Dynamical Systems, Signal Processing and Data Analytics (STADIUS), Department of Electrical Engineering (ESAT), KU (Katholieke Universiteit) Leuven, Leuven, Belgium
- imec vzw Belgium, Leuven, Belgium
| | - Sabine Van Huffel
- Center for Dynamical Systems, Signal Processing and Data Analytics (STADIUS), Department of Electrical Engineering (ESAT), KU (Katholieke Universiteit) Leuven, Leuven, Belgium
| | | | - Pieter Vandervoort
- Mobile Health Unit, Limburg Clinical Research Center (LCRC), Faculty of Medicine and Life Sciences, Hasselt University (UHasselt), Diepenbeek, Belgium
- Department of Future Health, Ziekenhuis Oost-Limburg, Genk, Belgium
- Department of Cardiology, Ziekenhuis Oost-Limburg, Genk, Belgium
| |
Collapse
|
2
|
Fagoni N, Bruseghini P, Adami A, Capelli C, Lador F, Moia C, Tam E, Bringard A, Ferretti G. Effect of Lower Body Negative Pressure on Phase I Cardiovascular Responses at Exercise Onset. Int J Sports Med 2020; 41:209-218. [PMID: 31958874 PMCID: PMC7286127 DOI: 10.1055/a-1028-7496] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We hypothesised that vagal withdrawal and increased venous return interact in determining the
rapid cardiac output (CO) response (phase I) at exercise onset. We used lower body negative
pressure (LBNP) to increase blood distribution to the heart by muscle pump action and reduce
resting vagal activity. We expected a larger increase in stroke volume (SV) and smaller for
heart rate (HR) at progressively stronger LBNP levels, therefore CO response would remain
unchanged. To this aim ten young, healthy males performed a 50 W exercise in supine
position at 0 (Control), −15, −30 and −45 mmHg LBNP exposure.
On single beat basis, we measured HR, SV, and CO. Oxygen uptake was measured breath-by-breath.
Phase I response amplitudes were obtained applying an exponential model. LBNP increased SV
response amplitude threefold from Control to −45 mmHg. HR response amplitude
tended to decrease and prevented changes in CO response. The rapid response of CO explained
that of oxygen uptake. The rapid SV kinetics at exercise onset is compatible with an increased
venous return, whereas the vagal withdrawal conjecture cannot be dismissed for HR. The rapid CO
response may indeed be the result of two independent yet parallel mechanisms, one acting on SV,
the other on HR.
Collapse
Affiliation(s)
- Nazzareno Fagoni
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Paolo Bruseghini
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Alessandra Adami
- Department of Kinesiology, University of Rhode Island, United States
| | - Carlo Capelli
- Department of Physical Performances, Norwegian School of Sport Sciences, Oslo, Norway
| | - Frederic Lador
- Division de Pneumologie, Département des Spécialités de Médecine, Hôpitaux Universitaires de Genève, Geneva, Switzerland
| | - Christian Moia
- Département des Neurosciences Fondamentales, Université de Genève Centre Médical Universitaire, Geneve, Switzerland
| | - Enrico Tam
- Dipartimento di Scienze Neurologiche e della Visione, University of Verona, Verona, Italy
| | | | - Guido Ferretti
- Département des Neurosciences Fondamentales, Université de Genève Centre Médical Universitaire, Geneve, Switzerland
| |
Collapse
|
3
|
Trounson KM, Roberts S, Balloch A, Warmington SA. Light exercise heart rate on-kinetics: a comparison of data fitted with sigmoidal and exponential functions and the impact of fitness and exercise intensity. Physiol Rep 2018. [PMID: 28637705 PMCID: PMC5492202 DOI: 10.14814/phy2.13312] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
This study examined the suitability of sigmoidal (SIG) and exponential (EXP) functions for modeling HR kinetics at the onset of a 5‐min low‐intensity cycling ergometer exercise test (5MT). The effects of training status, absolute and relative workloads, and high versus low workloads on the accuracy and reliability of these functions were also examined. Untrained participants (UTabs; n = 13) performed 5MTs at 100W. One group of trained participants (n = 10) also performed 5MTs at 100W (ETabs). Another group of trained participants (n = 9) performed 5MTs at 45% and 60% V˙O2 max (ET45 and ET60, respectively). SIG and EXP functions were fitted to HR data from 5MTs. A 30‐s lead‐in time was included when fitting SIG functions. Functions were compared using the standard error of the regression (SER), and test‐retest reliability of curve parameters. SER for EXP functions was significantly lower than for SIG functions across all groups. When residuals from the 30‐s lead‐in time were omitted, EXP functions only outperformed SIG functions in ET60 (EXP, 2.7 ± 1.2 beats·min−1; SIG, 3.1 ± 1.1 beats·min−1: P < 0.05). Goodness of fit and test–retest reliability of curve parameters were best in ET60 and comparatively poor in UTabs. Overall, goodness of fit and test–retest reliability of curve parameters favored functions fitted to 5MTs performed by trained participants at a high and relative workload, while functions fitted to data from untrained participants exercising at a low and absolute workload were less accurate and reliable.
Collapse
Affiliation(s)
- Karl M Trounson
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria, Australia
| | - Spencer Roberts
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria, Australia
| | - Aaron Balloch
- School of Medical and Health Sciences, Edith Cowan University, Perth, Western Australia.,Fremantle Dockers Football Club, Perth, Western Australia
| | - Stuart A Warmington
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria, Australia
| |
Collapse
|
4
|
Cardiac acceleration at the onset of exercise: a potential parameter for monitoring progress during physical training in sports and rehabilitation. Sports Med 2014; 44:591-602. [PMID: 24469736 DOI: 10.1007/s40279-013-0141-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
There is a need for easy-to-use methods to assess training progress in sports and rehabilitation research. The present review investigated whether cardiac acceleration at the onset of physical exercise (HRonset) can be used as a monitoring variable. The digital databases of Scopus and PubMed were searched to retrieve studies investigating HRonset. In total 652 studies were retrieved. These articles were then classified as having emphasis on HRonset in a sports or rehabilitation setting, which resulted in 8 of 112 studies with a sports application and 6 of 68 studies with a rehabilitation application that met inclusion criteria. Two co-existing mechanisms underlie HRonset: feedforward (central command) and feedback (mechanoreflex, metaboreflex, baroreflex) control. A number of studies investigated HRonset during the first few seconds of exercise (HRonsetshort), in which central command and the mechanoreflex determine vagal withdrawal, the major mechanism by which heart rate (HR) increases. In subsequent sports and rehabilitation studies, interest focused on HRonset during dynamic exercise over a longer period of time (HRonsetlong). Central command, mechanoreflexes, baroreflexes, and possibly metaboreflexes contribute to HRonset during the first seconds and minutes of exercise, which in turn leads to further vagal withdrawal and an increase in sympathetic activity. HRonset has been described as the increase in HR compared with resting state (delta HR) or by exponential modeling, with measurement intervals ranging from 0-4 s up to 2 min. Delta HR was used to evaluate HRonsetshort over the first 4 s of exercise, as well as for analyzing HRonsetlong. In exponential modeling, the HR response to dynamic exercise is biphasic, consisting of fast (parasympathetic, 0-10 s) and slow (sympathetic, 1-4 min) components. Although available studies differed largely in measurement protocols, cross-sectional and longitudinal training studies showed that studies analyzing HRonset in relation to physical training primarily incorporated HRonsetlong. HRonsetlong slowed in athletes as well as in patients with a coronary disease, who have a relatively fast HRonsetlong. It is advised to include both HRonsetlong and HRonsetshort in further studies. The findings of this review suggest that HRonset is a potential tool for monitoring and titrating training in sports as well as in rehabilitation settings, particularly in patients with ventricular fibrillation. Monitoring HRonset in the early phase of training can help optimize the effectiveness of training and therapy. More research is needed to gain a better understanding of the mechanisms underlying HRonset in relation to their application in sports and rehabilitation settings.
Collapse
|
5
|
Romero-Ortuno R, Cogan L, Foran T, Kenny RA, Fan CW. Continuous Noninvasive Orthostatic Blood Pressure Measurements and Their Relationship with Orthostatic Intolerance, Falls, and Frailty in Older People. J Am Geriatr Soc 2011; 59:655-65. [DOI: 10.1111/j.1532-5415.2011.03352.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
6
|
Koenig AC, Somaini L, Pulfer M, Holenstein T, Omlin X, Wieser M, Riener R. Model-based Heart rate prediction during Lokomat walking. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2010; 2009:1758-61. [PMID: 19963765 DOI: 10.1109/iembs.2009.5333096] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We implemented a model for prediction of heart rate during Lokomat walking. Using this model, we can predict potential overstressing of the patient and adapt the physical load accordingly. Current models for treadmill based heart rate control neglect the fact that the interaction torques between Lokomat and human can have a significant effect on heart rate. Tests with five healthy subjects lead to a model of sixth order with walking speed and power expenditure as inputs and heart rate prediction as output. Recordings with five different subjects were used for model validation. Future work includes model identification and predictive heart rate control with spinal cord injured and stroke patients.
Collapse
Affiliation(s)
- Alexander C Koenig
- Sensory Motor Systems Lab, ETH Zurich, Institute of Robotics and Intelligent Systems, Department of Mechanical Engineering and Process Engineering, ETH Zurich, Switzerland.
| | | | | | | | | | | | | |
Collapse
|
7
|
Cade WT, Fantry LE, Nabar SR, Shaw DK, Keyser RE. Impaired oxygen on-kinetics in persons with human immunodeficiency virus are not due to highly active antiretroviral therapy. Arch Phys Med Rehabil 2004; 84:1831-8. [PMID: 14669191 DOI: 10.1016/j.apmr.2003.03.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To determine the effects of human immunodeficiency virus (HIV) and highly active antiretroviral therapy (HAART) on oxygen on-kinetics in HIV-positive persons. DESIGN Quasi-experimental cross-sectional. SETTING Infectious disease clinic and exercise laboratory. PARTICIPANTS Referred participants (N=39) included 13 HIV-positive participants taking HAART, 13 HIV-positive participants not taking HAART, and 13 noninfected controls. INTERVENTIONS Participants performed 1 submaximal exercise treadmill test below the ventilatory threshold, 1 above the ventilatory threshold, and 1 maximal treadmill exercise test to exhaustion. MAIN OUTCOME MEASURES Change in oxygen consumption (Delta.VO2) and oxidative response index (Delta.VO2/mean response time). RESULTS Delta.VO2 was significantly lower in both HIV-positive participants taking (946.5+/-68.1mL) and not taking (871.6+/-119.6mL) HAART than in controls (1265.3+/-99.8mL) during submaximal exercise above the ventilatory threshold. The oxidative response index was also significantly lower (P<.05) in HIV-positive participants both taking (15.0+/-1.3mL/s) and not taking (15.1+/-1.7mL/s) HAART than in controls (20.8+/-2.1mL/s) during exercise above the ventilatory threshold. CONCLUSION Oxygen on-kinetics during submaximal exercise above the ventilatory threshold was impaired in HIV-positive participants compared with a control group, and it appeared that the attenuated oxygen on-kinetic response was primarily caused by HIV infection rather than HAART.
Collapse
Affiliation(s)
- W Todd Cade
- Department of Physical Therapy, University of Maryland School of Medicine, Baltimore, MD, USA.
| | | | | | | | | |
Collapse
|
8
|
Sone R, Tan N, Nishiyasu T, Yamazaki F. Autonomic Heart Rate Regulation during Mild Dynamic Exercise in Humans: Insights from Respiratory Sinus Arrhythmia. ACTA ACUST UNITED AC 2004; 54:273-84. [PMID: 15541205 DOI: 10.2170/jjphysiol.54.273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
To better understand the neural mechanism of heart rate (HR) regulation during dynamic exercise, the responses of HR and the magnitude of respiratory R-R interval variation were examined during exercise and recovery at mild intensities in humans. Eight subjects performed 3-min constant load cycle exercises in a semi-supine position at work rates of 25, 50, and 100 W. The respiratory interval was fixed at 4 s. Peak-to-valley variation in R-R interval caused by respiration was measured breath-by-breath and standardized for tidal volume (DeltaRRst, a noninvasive index of the degree of parasympathetic cardiac control). At all work rates the HR increased significantly from 2.5 s after the beginning of exercise (p <0.05) and decreased temporarily and slightly at around 15 s, and the DeltaRRst varied almost inversely. The HR and the DeltaRRst until 12.5 s after the beginning of exercise changed independently of work rate (ANOVA, p=0.27 and p=0.08). The HR-DeltaRRst relationship at the initial phase of exercise (for 12.5 s) was almost the same at all work rates. These results suggest that the initial HR response to exercise is strongly parasympathetically regulated independently of work rate. The HR recovered slower than the DeltaRRst at 50 and 100 W. On the HR-DeltaRRst relationship, the HR during recovery was significantly higher than during exercise at 1/3, 1/2, and 2/3 levels of pre-exercise DeltaRRst at 50 and 100 W and at the 1/3 level at 25 W (p < 0.05). At 25 W, the difference in HR at the 1/3 level was 5.5 beats.min(-1), and the HR increase to exercise was 21.2 beats.min(-1). We suggest that a HR regulatory system responds slower than a cardiac parasympathetic system to exercise, a cardiac sympathetic system, is activated even during mild exercise in humans.
Collapse
Affiliation(s)
- R Sone
- Department of Exercise and Health Science, Faculty of Education, Yamaguchi University, Yamaguchi, Yamaguchi, 753-8513 Japan.
| | | | | | | |
Collapse
|
9
|
Ishida K, Sato Y, Katayama K, Miyamura M. Initial ventilatory and circulatory responses to dynamic exercise are slowed in the elderly. J Appl Physiol (1985) 2000; 89:1771-7. [PMID: 11053325 DOI: 10.1152/jappl.2000.89.5.1771] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To elucidate the characteristics of ventilatory and circulatory responses at the onset of brief and light exercise in the elderly, 13 healthy, elderly men, aged 66.8 yr (mean), exerted bilateral leg extension-flexion movements for only 20 s with a weight around each ankle, with each weight being approximately 2.5% of their body mass. Similar movements were passively performed on the subjects by the experimenters. These results were compared with those of 13 healthy, young men (22.9 yr). Minute ventilation increased at the onset of voluntary exercise and passive movements in both groups but showed a slower increase in the elderly. Heart rate also increased in both groups but showed less change in the elderly. Mean blood pressure temporarily decreased in both groups but less in the elderly. The magnitude of relative change (gain) of heart rate in the elderly was significantly smaller than that in the young, whereas the increasing rate to reach one-half of the gain (response time) of ventilation in the elderly was significantly slower than that in the young. Similar tendencies were observed in the passive movements. It is concluded that the elderly show slower ventilatory response and attenuated circulatory response at the onset of dynamic voluntary exercise and passive movements.
Collapse
Affiliation(s)
- K Ishida
- Laboratory for Exercise Physiology, Research Center of Health, Physical Fitness and Sports, Japan.
| | | | | | | |
Collapse
|
10
|
Ishijima M, Togawa T. Chronodiagnostic acquisition of recovery speed of heart rate under bathing stress. Physiol Meas 1999; 20:369-75. [PMID: 10593230 DOI: 10.1088/0967-3334/20/4/304] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Cycling on an ergometer is one effective means of measuring cardiovascular function while applying stress on the heart. Bathing in a hot water bath applies a low stress to the heart. The electrocardiograms of a healthy adult male (aged 35 at the start of study) were recorded while taking a hot water bath with no electrode attached to the body over a period of 2 years (376 days over a 762 day period). The recovery speed following the initial overshoot of the heart rate (HR) was observed. The bathtub was designed for the automatic acquisition of ECG data. Immediately after immersion in the tub, the HR reached a peak within 20 s and then exponentially decreased toward the lowest rate in the 120 s of bathing. The initial recovery speed of the HR from the stress of bathing had a specific rhythm in the subject. Spectrum analysis of the speed series indicated that slow recovery speed appeared in cyclic periods of approximately 1 year, 42 days and 17 days. The methodology may provide a chronodiagnostic index of an exercise test for cardiovascular function.
Collapse
Affiliation(s)
- M Ishijima
- Institute of Biomedical Engineering, Tokyo Women's Medical University, Kawada, Japan
| | | |
Collapse
|
11
|
Fukuba Y, Haouzi P, Chalon B. Heart rate dynamics during sinusoidal exercise: comparison of the control system between children and adults. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 1999; 60:35-44. [PMID: 10430461 DOI: 10.1016/s0169-2607(99)00009-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The aim was to model the dynamics of heart rate (HR) response to sinusoidal work rate (WR) forcing in children and adults. Seven pre-pubertal boys (aged 10-13) and five adult males (aged 22-37) were studied. Continuous ECG recordings were obtained during the following physiological manoeuvres: five constant amplitude ergometer exercises with WR varying sinusoidally with periods of 0.75, 1, 2, 3.5, and 5 min duration, and one step exercise at a constant WR equal to the midpoint of the sinusoid amplitude. The amplitude ratio (AR; standardized by WR) of the fundamental harmonic of the HR response and the phase shift (phi) between the WR to HR were calculated by Fourier analysis. The HR dynamic parameters (gain and time constant (tau)) of a first order model with or without delay (Td) were also estimated. The AR in children was always higher than that in adults, in absolute terms, but not as a function of body weight. The phi was more delayed in the children than the adults only for the shortest period, i.e. 0.75 min. The tau for the first order model, either without or with Td, was found to be no difference between children and adults (44.7 vs. 45.9 s (without Td), 34.9 vs. 42.3 s (with Td)). Td, however, was longer in the children (6.6 vs. 2.3 s). The goodness of fit for the first order model with Td was better than that without Td in children, i.e. due to the difference of phi for 0.75 min period, whereas the HR dynamics in adults was appropriately described by first order model without Td. It is concluded that the fundamental control of HR to sinusoidal exercise between children and adults was not appreciably different, except for a small Td difference at high sinusoidal frequency.
Collapse
Affiliation(s)
- Y Fukuba
- Department of Exercise Science and Physiology, School of Health Sciences, Hiroshima Women's University, Japan.
| | | | | |
Collapse
|
12
|
Shin K, Minamitani H, Onishi S, Yamazaki H, Lee M. The power spectral analysis of heart rate variability in athletes during dynamic exercise--Part II. Clin Cardiol 1995; 18:664-8. [PMID: 8590537 DOI: 10.1002/clc.4960181114] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Affiliation(s)
- K Shin
- Department of Biomedical Engineering, Faculty of Science and Technology, Keio University, Kanagawa, Japan
| | | | | | | | | |
Collapse
|
13
|
Nóbrega AC, Williamson JW, Araújo CG, Friedman DB. Heart rate and blood pressure responses at the onset of dynamic exercise: effect of Valsalva manoeuvre. EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY 1994; 68:336-40. [PMID: 8055892 DOI: 10.1007/bf00571453] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The influence of respiration on the mean blood pressure (Pa) and R-R interval responses at the onset of dynamic exercise was studied in 15 healthy subjects who performed 4 s of unloaded cycling at 1.5-2.0 Hz, 4 s of Valsalva manoeuvre at 5.3 kPa, and a combination of both, each during a 12-s long apnoea at total lung capacity. The R-R intervals were obtained from the electrocardiogram, Pa was measured continuously by finger plethysmography, and intra-oral pressure was used to estimate the changes in intrapleural pressure. There was an immediate and significant shortening of the R-R intervals during exercise [mean (SE): 790 (20) to 642 (20) ms] that was not modified when Valsalva manoeuvre was added [783 (28) to 654 (21) ms]. Although 4 s of exercise alone did not alter Pa [13.8 (0.5) to 13.7 (0.7) kPa], this may indicate a pressor response, since Pa decreased during apnoea alone. When exercise was performed simultaneously with Valsalva manoeuvre, Pa increased significantly [13.6 (0.4) to 15.8 (0.5) kPa] and of similar magnitude during Valsalva alone [13.2 (0.4) to 15.3 (0.7) kPa]. In conclusion, 4 s of unloaded cycling elicited a fast R-R shortening with no change in Pa from rest. A concomitant Valsalva manoeuvre had no effect on the R-R interval response but caused a marked increase in Pa. From these findings, it is suggested that respiratory influences should be controlled in studies concerned with the cardiovascular responses at the onset of dynamic exercise.
Collapse
Affiliation(s)
- A C Nóbrega
- Harry S. Moss Heart Center, University of Texas Southwestern Medical Center, Dallas 75235-9034
| | | | | | | |
Collapse
|