Artificial pacemaker for treatment of Adams-Stokes syndrome and slow heart rate

Estimation of Heart Rate Variability Fluctuations by Wavelet TransformTechnique for separate estimation of fast and slow fluctuations in the heart rate signal is developed. The orthogonal dyadic wavelet transform is used to separate the slow heart rate changes in approximation part of decomposition and fast changes in detail parts. Experimental results using the recordings from persons practicing Chi meditation demonstrated the applicability of estimation heart rate fluctuations with the proposed approach.

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Regulation of mitochondrial matrix pH and adenosine 5′-triphosphatase activity during ischemia in slow heart-rate hearts

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)84813-5 ◽

1989 ◽

Vol 264 (26) ◽

pp. 15224-15229

Author(s):

W Rouslin ◽

C W Broge

Keyword(s):

Heart Rate ◽

Mitochondrial Matrix ◽

Slow Heart Rate

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Mechanisms of ATP conservation during ischemia in slow and fast heart rate hearts

AJP Cell Physiology ◽

10.1152/ajpcell.1993.264.1.c209 ◽

1993 ◽

Vol 264 (1) ◽

pp. C209-C216 ◽

Cited By ~ 24

Author(s):

W. Rouslin ◽

C. W. Broge

Keyword(s):

Heart Rate ◽

Cardiac Muscle ◽

Rat Heart ◽

Heart Mitochondria ◽

Glycolytic Flux ◽

Mitochondrial Atpase ◽

Dog Heart ◽

Slow Heart Rate ◽

Atpase Inhibition ◽

Fast Heart Rate

In the present study we compared the quantitatively most important, Pi-activated mechanisms for conserving ATP during ischemia in dog and rat cardiac muscle. Earlier studies by ourselves showed that dog heart, like all slow heart rate mammalian hearts examined, possesses the ability to inhibit its mitochondrial ATPase by binding IF1, the ATPase inhibitor protein, during ischemia. Rat heart, like other fast heart rate mammalian hearts studied, does not. The present study demonstrated that this IF1-mediated ATPase inhibition in ischemic dog heart, as in other slow heart rate hearts, appears to depend on matrix space acidification mediated largely by Pi-H+ symport via the mitochondrial Pi carrier. The present study further confirmed that maximal glycolytic flux rates are five- to sixfold greater in ischemic rat than in ischemic dog heart. Both of these systems are activated by increasing Pi concentration ([Pi]) during ischemia, and both appear to be regulated somewhat differently in dog than in rat heart. Thus intact dog heart mitochondria exhibited a [Pi]-dependent ATPase inhibition at low external pH, whereas rat heart mitochondria did not. The [Pi] required for maximal ATPase inhibition in dog heart mitochondria was approximately 6 mM. Although both dog and rat heart phosphofructokinase were stimulated by Pi, the enzyme in dog heart was maximally activated by approximately 6 mM Pi, whereas the rat heart enzyme required only approximately 3 mM Pi for its maximal stimulation under otherwise identical conditions. The most active nonmitochondrial ATPase in ischemic dog and rat cardiac muscle, the Ca(2+)-activated actomyosin ATPase, accounted for approximately one-half of the total nonmitochondrial ATPase activity in each species.(ABSTRACT TRUNCATED AT 250 WORDS)

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BRADYCARDIA IN ATHLETES: DOES THE TYPE OF SPORT MAKE ANY DIFFERENCE? – A SYSTEMATIC REVIEW

Revista Brasileira de Medicina do Esporte ◽

10.1590/1517-8692202026052019_0001 ◽

2020 ◽

Vol 26 (5) ◽

pp. 449-453

Author(s):

Michelle Teles Morlin ◽

Carlos Janssen Gomes da Cruz ◽

Paula Beatriz Silvestre Melo ◽

Guilherme Henrique Ramos Lopes ◽

Edgar de Melo Keene Von Koening Soares ◽

...

Keyword(s):

Heart Rate ◽

English Language ◽

Female Athletes ◽

Cardiac Structure ◽

Resting Heart Rate ◽

Level Of Evidence ◽

Cardiac Responses ◽

Vagal Modulation ◽

Slow Heart Rate ◽

Pharmacological Blockade

ABSTRACT Bradycardia in athletes can range from moderate to severe, and the factors that contribute to slow heart rate are complex. Studies investigating the mechanisms associated with this condition are controversial, and may be linked to the form of exercise practiced. A systematic literature review was conducted to discuss bradycardia mechanisms in athletes who practice different forms of sport. The databases consulted were Pubmed (MEDLINE), Clinical Trials, Cochrane, Scopus, Web of Science, SciELO, Sport Discus and PEDro. The search included English language articles published up to January 2019, that evaluated athletes who practiced different forms of sport. One hundred and ninety-three articles were found, ten of which met the inclusion criteria, with 1549 male and female athletes who practiced diverse forms of sport. Resting heart rate and cardiac structure were studied in association with the form of sport practiced, through heart rate variability, electrocardiogram, echocardiogram and pharmacological blockade. The studies suggest that a slow resting heart rate cannot be explained by increased vagal modulation alone, but also includes changes in cardiac structure. According to the studies, different sports seem to produce different cardiac responses, and the bradycardia found in athletes can be explained by non-autonomic and autonomic mechanisms, depending on the type of effort or the form of sport practiced. However, the mechanism underlying the slow heart rate in each form of sport is still unclear. Level of evidence II; Prognostic studies - Investigating the effect of a patient characteristic on the outcome of disease.

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Dizziness and slow heart rate during exercise

Netherlands Heart Journal ◽

10.1007/s12471-017-0985-0 ◽

2017 ◽

Vol 25 (7-8) ◽

pp. 465-466 ◽

Cited By ~ 1

Author(s):

R. Joustra ◽

M. Boulaksil ◽

H. W. Meijburg ◽

J. L. Smeets

Keyword(s):

Heart Rate ◽

Slow Heart Rate

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Slow Heart Rate Within 72 Hours After Cardiac Arrest Is Associated with Good Neurologic Outcome in Out-of-Hospital Cardiac Arrest Survivors Who Undergo Targeted Temperature Management with 33°C

Therapeutic Hypothermia and Temperature Management ◽

10.1089/ther.2020.0021 ◽

2020 ◽

Author(s):

Dong Hun Lee ◽

Byung Kook Lee ◽

Yong Soo Cho ◽

Yong Hun Jung ◽

Hyoung Youn Lee ◽

...

Keyword(s):

Heart Rate ◽

Cardiac Arrest ◽

Targeted Temperature Management ◽

Neurologic Outcome ◽

Temperature Management ◽

Slow Heart Rate ◽

Good Neurologic Outcome ◽

Hospital Cardiac Arrest

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Oxygen uptake kinetics in cardiac transplant recipients

Journal of Applied Physiology ◽

10.1152/jappl.1994.77.4.1935 ◽

1994 ◽

Vol 77 (4) ◽

pp. 1935-1940 ◽

Cited By ~ 18

Author(s):

D. H. Paterson ◽

D. A. Cunningham ◽

J. G. Pickering ◽

M. A. Babcock ◽

D. R. Boughner

Keyword(s):

Heart Rate ◽

Gas Exchange ◽

Oxygen Uptake Kinetics ◽

Uptake Kinetics ◽

Cardiac Transplant ◽

O2 Uptake ◽

Square Wave ◽

Forcing Function ◽

Slow Heart Rate ◽

O2 Delivery

Our purpose was to examine the gas exchange response to exercise in heart transplant (HT) patients and to characterize the O2 uptake kinetics (tau VO2) during successive square-wave on-transients from loadless cycling to moderate exercise. We hypothesized that with a slow heart rate response (and O2 transport limitation) O2 kinetics would be slowed but that with a repeated exercise initiated while the heart rate remained elevated the tau VO2 would be faster. Six male HT patients performed two ramp-function tests to determine peak O2 uptake (1.32 +/- 0.23 l/min) and ventilation threshold (1.02 +/- 0.16 l/min). Patients subsequently completed two repeats of a square-wave forcing function and repeated this on 2 days. Alveolar gas exchange was measured breath by breath. A monoexponential fit of signal-averaged data of the first exercise on-transient (between days) yielded a significantly slower tau VO2 in HT subjects than in healthy men (mean age 47 yr; n = 8) (77 +/- 26 vs. 45 +/- 4 s). With successive exercise (2nd transition) initiated while HR remained elevated the tau VO2 of HT patients was 46 +/- 17 s. The faster O2 kinetics of the second transition suggests that O2 delivery was enhanced and therefore that the tau VO2 may reflect bioenergetic processes controlling the rate of oxidative metabolism.

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