THE RELATIONSHIP OF SHORT-TERM MEASURES OF HRV TO HEART RATE AND EXERCISE INTENSITY 795

AbstractThe purpose of this study was to investigate the relationship between heart rate variability (HRV), a non-invasive tool for evaluating autonomic function, and routine coagulation indices (RCIs) in patients with breast cancer (BC). Forty-six BC patients were enrolled in this study. Blood biochemistry tests were performed to extract RCIs, including prothrombin time (PT), activated partial thromboplastin time (APTT), and thrombin time (TT). Five-minute electrocardiograms were collected for analysis of HRV parameters (SDNN, RMSSD, LF, HF, LF n.u., HF n.u., LF/HF). Multiple linear regression models examined the relationship of HRV parameters with RCIs. RMSSD, LF n.u., HF n.u., LF/HF were significantly associated with PT. Specifically, the value of PT increased by 0.192 ± 0.091 or 0.231 ± 0.088 s, respectively for each 1 standard deviation (SD) increase in RMSSD or HF n.u.; it increased by 0.230 ± 0.088 or 0.215 ± 0.088 s, respectively for each 1 − SD decrease in LF n.u. or ln (LF/HF) (all P < 0.05). RMSSD was significantly associated with APTT, i.e., the value of APTT increased by 1.032 ± 0.470 s for each 1 − SD increase in RMSSD (P < 0.05). HRV parameters were associated with RCIs in patients with BC. These observations suggest that the autonomic nervous system and coagulation indices in BC patients are linked, potentially explaining the reason that they are both associated with the prognosis.

Download Full-text

Energy expenditure by elite midget male ice hockey players in small-sided games

International Journal of Sports Science & Coaching ◽

10.1177/1747954117718075 ◽

2017 ◽

Vol 12 (4) ◽

pp. 504-513 ◽

Cited By ~ 1

Author(s):

Charles-Mathieu Lachaume ◽

François Trudeau ◽

Jean Lemoyne

Keyword(s):

Heart Rate ◽

Oxygen Consumption ◽

Energy Expenditure ◽

Ice Hockey ◽

Training Method ◽

Hockey Players ◽

Treadmill Testing ◽

Effective Training ◽

Relationship Of ◽

The Relationship

The purpose of this study was to investigate the energy expenditure and heart rate responses elicited in elite male midget ice hockey players during small-sided games. Nine players (aged 15.89 ± 0.33 years) participated in the study. Maximal progressive treadmill testing in the laboratory measured the relationship of oxygen consumption ([Formula: see text]) to heart rate before on-ice assessments of heart rate during six different small-sided games: 1v1, 2v2, 2v2 with support player, 3v3 with support player, 3v3 with transitions, and 4v4 with two support players. Heart rate was recorded continuously in each game. 3v3 T small-sided game was the most intense for all four intensity markers. All six small-sided games reached 89% HRmax or more with heart rate peaks in active effort repetition. These findings demonstrate that such small-sided games are considered as high intensity games and are an effective training method for ice hockey players.

Download Full-text

Short-term Periodic Observation of the Relationship of Climate Variables to Groundwater Quality along the KT Boundary

Journal of Climate Change ◽

10.3233/jcc-1800015 ◽

2018 ◽

Vol 4 (2) ◽

pp. 77-86 ◽

Cited By ~ 4

Author(s):

C. Thivya ◽

S. Chidambaram ◽

R. Thilagavathi ◽

Venkatraman ◽

N. Ganesh ◽

...

Keyword(s):

Groundwater Quality ◽

Climate Variables ◽

Short Term ◽

Relationship Of ◽

The Relationship

Download Full-text

Variability of Burnout and Stress Measures in Pediatric Residents: An Exploratory Single-Center Study From the Pediatric Resident Burnout–Resilience Study Consortium

Journal of Evidence-Based Integrative Medicine ◽

10.1177/2515690x18804779 ◽

2018 ◽

Vol 23 ◽

pp. 2515690X1880477

Author(s):

Suzanne Reed ◽

Kathi J. Kemper ◽

Alan Schwartz ◽

Maneesh Batra ◽

Betty B. Staples ◽

...

Keyword(s):

Compassionate Care ◽

Short Term ◽

Cross Sectional ◽

Pediatric Residents ◽

Time Points ◽

Single Center Study ◽

Risk Period ◽

Resident Burnout ◽

Relationship Of ◽

The Relationship

Residency is a high-risk period for physician burnout. We aimed to determine the short-term stability of factors associated with burnout, application of these data to previous conceptual models, and the relationship of these factors over 3 months. Physician wellness questionnaire results were analyzed at 2 time points 3 months apart. Associations among variables within and across time points were analyzed. Logistic regression was used to predict burnout and compassionate care. A total of 74% of residents completed surveys. Over 3 months, burnout ( P = .005) and empathy ( P = .04) worsened. The most significant cross-sectional relationship was between stress and emotional exhaustion (time 1 r = 0.61, time 2 r = 0.68). Resilience was predictive of increased compassionate care and decreased burnout ( P < .05). Mindfulness was predictive of decreased burnout ( P < .05). Mitigating stress and fostering mindfulness and resilience longitudinally may be key areas of focus for improved wellness in pediatric residents. Larger studies are needed to better develop targeted wellness interventions.

Download Full-text

Heart Rate Dependency and Inter-Lead Variability of the T Peak – T End Intervals

Frontiers in Physiology ◽

10.3389/fphys.2020.595815 ◽

2020 ◽

Vol 11 ◽

Author(s):

Irena Andršová ◽

Katerina Hnatkova ◽

Martina Šišáková ◽

Ondřej Toman ◽

Peter Smetana ◽

...

Keyword(s):

Heart Rate ◽

Three Dimensional ◽

Rate Dependency ◽

Rate Dependent ◽

Heart Rate Correction ◽

Ecg Leads ◽

Relationship Of ◽

The Relationship ◽

Vector Magnitude

The electrocardiographic (ECG) assessment of the T peak–T end (Tpe) intervals has been used in many clinical studies, but several related physiological aspects have not been reported. Specifically, the sources of the Tpe differences between different ECG leads have not been systematically researched, the relationship of Tpe duration to underlying heart rate has not been firmly established, and little is known about the mutual correspondence of Tpe intervals measured in different ECG leads. This study evaluated 796,620 10-s 12-lead ECGs obtained from long-term Holters recorded in 639 healthy subjects (311 female) aged 33.8 ± 9.4 years. For each ECG, transformation to orthogonal XYZ lead was used to measure Tpe in the orthogonal vector magnitude (used as a reference for lead-to-lead comparisons) and to construct a three-dimensional T wave loop. The loop roundness was expressed by a ratio between its circumference and length. These ratios were significantly related to the standard deviation of Tpe durations in different ECG leads. At the underlying heart rate of 60 beats per minute, Tpe intervals were shorter in female than in male individuals (82.5 ± 5.6 vs 90.0 ± 6.5 ms, p < 0.0001). When studying linear slopes between Tpe intervals measured in different leads and the underlying heart rate, we found only minimal heart rate dependency, which was not systematic across the ECG leads and/or across the population. For any ECG lead, positive Tpe/RR slope was found in some subjects (e.g., 79 and 25% of subjects for V2 and V4 measurements, respectively) and a negative Tpe/RR slope in other subjects (e.g., 40 and 65% for V6 and V5, respectively). The steepest positive and negative Tpe/RR slopes were found for measurements in lead V2 and V4, respectively. In all leads, the Tpe/RR slope values were close to zero, indicating, on average, Tpe changes well below 2 ms for RR interval changes of 100 ms. On average, longest Tpe intervals were measured in lead V2, the shortest in lead III. The study concludes that the Tpe intervals measured in different leads cannot be combined. Irrespective of the measured ECG lead, the Tpe interval is not systematically heart rate dependent, and no heart rate correction should be used in clinical Tpe investigations.

Download Full-text

Relationship of potassium ions and blood lactate to ventilation during exercise

Applied Physiology Nutrition and Metabolism ◽

10.1139/h10-063 ◽

2010 ◽

Vol 35 (5) ◽

pp. 691-698

Author(s):

Robert G. McMurray ◽

Matthew S. Tenan

Keyword(s):

Blood Lactate ◽

Exercise Intensity ◽

Minute Ventilation ◽

Potassium Ions ◽

Ventilatory Control ◽

Volitional Fatigue ◽

Relationship Of ◽

Glycogen Stores ◽

The Relationship ◽

Recent Attention

Ventilatory control during exercise is a complex network of neural and humoral signals. One humoral input that has received little recent attention in the exercise literature is potassium ions [K+]. The purpose of this study was to examine the relationship between [K+] and ventilation during an incremental cycle test and to determine if the relationship between [K+] and ventilation differs when blood lactate [lac–] is manipulated. Eight experienced triathletes (4 of each sex) completed 2 incremental, progressive (5-min stages) cycle tests to volitional fatigue: 1 with normal glycogen stores and 1 with reduced glycogen. Minute ventilation was measured during the final minute of each stage, and blood [lac–] and [K+] were measured at the end of each exercise stage. Minute ventilation and [K+] increased with exercise intensity and were similar between trials (p > 0.5), despite lower [lac–] during the reduced-glycogen trial. The concordance correlations (Rc) between [lac–] and minute ventilation were stronger for both trials (Rc = ~0.88–0.96), but the slopes of the relationships were different than the relationships between [K+] and minute ventilation (Rc = ~0.76–0.89). The slope of the relationship between [lac–] and minute ventilation was not as steep during the reduced-glycogen trial, compared with the normal trial (p = 0.002). Conversely, the slope of the relationships between [K+] and minute ventilation did not change between trials (p = 0.454). The consistent relationship of minute ventilation and blood [K+] during exercise suggests a role for this ion in the control of ventilation during exercise. Conversely, the inconsistent relationship between blood lactate and ventilation brings into question the importance of the relationship between lactate and ventilation during exercise.

Download Full-text

Factors Contributing to Intra-Individual Variation of Serum Constituents: 5. Short-Term Day-to-Day and Within-Hour Variation of Serum Constituents in Healthy Subjects

Clinical Chemistry ◽

10.1093/clinchem/20.12.1520 ◽

1974 ◽

Vol 20 (12) ◽

pp. 1520-1527 ◽

Cited By ~ 30

Author(s):

Per Winkel ◽

Bernard E Statland ◽

Henning Bokelund

Keyword(s):

Total Lipids ◽

Short Term ◽

Serum Samples ◽

Interaction Terms ◽

Anova Model ◽

First Case ◽

Main Effect ◽

Relationship Of ◽

The Relationship ◽

Analytical Variation

Abstract We evaluated the variations in some serum constituents in a group of healthy young men for two selected time intervals: short-term day-to-day changes and within-hour changes. In the first case, we used a two-way ANOVA model to compute the main-day effect and the subject-day interaction terms, which were combined to yield the total day-to-day variation. A main-day effect was seen to be statistically significant only for acid phosphatase, while all of the 18 serum constituents except for sodium, calcium, and albumin demonstrated a statistically significant subject-day interaction. For the within-hour biologic variation, a three-way ANOVA model was used to analyze results of duplicate serum samples drawn at 1100 h and 1130 h on two different days. Although a significant main effect of hour was found only for total lipids and alkaline phosphatase, pooling the main effect of hour, subject-hour interaction, and subject-day-hour interaction terms resulted in a chemically significant variation for potassium, total protein, albumin, iron, total lipids, cholesterol, and bilirubin. The relationship of these biological fluctuations is compared to the expected analytical variation in all cases.

Download Full-text

The relationship of capital structure decisions with firm performance: A study of the engineering sector of Pakistan

International Journal of Accounting and Financial Reporting ◽

10.5296/ijafr.v2i1.1825 ◽

2012 ◽

Vol 2 (1) ◽

pp. 245 ◽

Cited By ~ 14

Author(s):

Abdul Ghafoor Khan

Keyword(s):

Firm Performance ◽

Capital Structure ◽

Negative Relationship ◽

Engineering Industry ◽

Tobin’S Q ◽

Financial Leverage ◽

Short Term ◽

Tobin's Q ◽

Relationship Of ◽

The Relationship

Purpose: The purpose of this study is to find the relationship of capital structure decision with the performance of the firms in the developing market economies like Pakistan.Methodology: Pooled Ordinary Least Square regression was applied to 36 engineering sector firms in Pakistani market listed on the Karachi Stock Exchange (KSE) during the period 2003-2009.Findings: The results show that financial leverage measured by short term debt to total assets (STDTA) and total debt to total assets (TDTA) has a significantly negative relationship with the firm performance measured by Return on Assets (ROA), Gross Profit Margin (GM) and Tobin’s Q. The relationship between financial leverage and firm performance measured by the return on equity (ROE) is negative but insignificant. Asset size has an insignificant relationship with the firm performance measured by ROA and GM but negative and significant relationship exists with Tobin’s Q. Firms in the engineering sector of Pakistan are largely dependent on short term debt but debts are attached with strong covenants which affect the performance of the firm.Originality/Value: This is first paper to study an individual sector like engineering industry in Pakistan on the mentioned topic.

Download Full-text

The relationship of trauma exposure to heart rate variability during wake and sleep in midlife women

Psychophysiology ◽

10.1111/psyp.13514 ◽

2019 ◽

Vol 57 (4) ◽

Author(s):

Rebecca C. Thurston ◽

Mary Y. Carson ◽

Karestan C. Koenen ◽

Yuefang Chang ◽

Karen A. Matthews ◽

...

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Trauma Exposure ◽

Midlife Women ◽

Relationship Of ◽

The Relationship

Download Full-text

The relationship between oxygen uptake reserve and heart rate reserve is affected by intensity and duration during aerobic exercise at constant work rate

Applied Physiology Nutrition and Metabolism ◽

10.1139/h11-100 ◽

2011 ◽

Vol 36 (6) ◽

pp. 839-847 ◽

Cited By ~ 8

Author(s):

Felipe A. Cunha ◽

Adrian W. Midgley ◽

Walace D. Monteiro ◽

Felipe K. Campos ◽

Paulo T.V. Farinatti

Keyword(s):

Heart Rate ◽

Oxygen Uptake ◽

Exercise Testing ◽

Exercise Intensity ◽

Maximal Exercise ◽

Work Rate ◽

Heart Rate Reserve ◽

Constant Work Rate ◽

The Stability ◽

The Relationship

The relationship between the percentage of heart rate reserve (%HRR) and percentage of oxygen uptake reserve (%VO2R) has been recommended for prescribing aerobic exercise intensity. However, this relationship was derived from progressive maximal exercise testing data, and the stability of the relationship during prolonged exercise at a constant work rate has not been established. The main aim of this study was to investigate the stability of the %VO2R–%HRR relationship during prolonged treadmill exercise bouts performed at 3 different constant work rates. Twenty-eight men performed 4 exercise tests: (i) a ramp-incremental maximal exercise test to determine maximal heart rate (HRmax) and maximal oxygen uptake (VO2max) and (ii) three 40-min exercise bouts at 60%, 70%, and 80% VO2R. HR and VO2 significantly increased over time and were influenced by exercise intensity (p < 0.001 and p = 0.004, respectively). A 1:1 relationship between %HRR and %VO2R, and between %HRR and %VO2max, was not observed, with mean differences of 8% (t = 5.2, p < 0.001) and 6% (t = 4.8, p < 0.001), respectively. The VO2 values predicted from the ACSM running equation were all significantly higher than the observed VO2 values (p < 0.001 for all comparisons), whereas a difference for HR was observed only for the tenth min of exercise at 80% VO2R (p = 0.041). In conclusion, the main finding of this study was that the %HRR–%VO2R relationship determined by linear regression, obtained from progressive maximal exercise testing, did not apply to prolonged treadmill running performed at 3 work rates.

Download Full-text