Aging effects on cycle length dependence of heart rate variability

2002 ◽  
Author(s):  
K. Umetani ◽  
C.L. Duda ◽  
D.H. Singer
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Cycle Length ◽  
Aging Effects ◽  
Length Dependence

scholarly journals Heart rate variability: Response to graded head up tilt in healthy men

1970 ◽  
Vol 7 (3) ◽  
pp. 252-257 ◽  
Author(s):  
P Sharma ◽  
BH Paudel ◽  
PN Singh ◽  
P Linmbu
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Sympathetic Activity ◽  
Cycle Length ◽  
Cardiac Cycle ◽  
Test Results ◽  
Successive Cycle ◽  
Head Up Tilt ◽  
Bonferroni Test ◽  
Lying Down

Background: Heart rate variability is actually a misnomer for R to R variability in cardiac cycle. Variation in successive cycle length is called the heart rate variability (HRV). Head-up tilt is a model of studying cardiovascular haemodynamics, which reflects in heart rate variability (HRV). Objectives: To study the effect of 10° and 70° head-up tilt on HRV. Materials and methods: The study was done in the Department of Physiology using graded head up tilt (passive orthostatism). HRV measurement was done at 10° and 70° tilt and compared with supine using standardised methods on 30 consenting healthy males (age 25.37±3.89 years). The HRV variables across postures were compared by ANOVA and Bonferroni test. Results: The heart rate increased at 70° compared to 10° and supine (70.48±8.17 Vs 70.22±8.67 and 88.51±12.84 bpm, p<0.001). The 70° tilt decreased vagal HRV indicators compared to 10° and supine: SDNN (31.13±8.12 Vs 38.07±11.29 and 38.13±10.89 ms, p<0.05), RMSSD (20.06 ±8.47 Vs 34.23±14.22 and 36.16±12.22 ms, p<0.001), NN50 count (13.03±20.58 Vs 45.07±44.44 and 55.27±44.10, p<0.01), pNN50 (3.28±6.08 Vs 14.06±15.65 and 16.65±14.23, p<0.01), HF power (197.20±143.76 Vs 218.17±155.85 and 216.87±150.98 Hz, p<0.05), HFnu unit (24.28±14.16 Vs 45.48±16.34 and 47.67±19.89, p<0.001). The 70° tilt increased LF power% (197.20±143.76 Vs 218.17±155.85 and 216.87±150.98, p<0.001). LFnu unit (75.72±14.76 Vs 54.52±16.34 and 52.32±19.89, p<0.001), LF: HF (4.96±4.08 Vs 1.53±1.138 and 1.69±1.67, p<0.001) compared to 10° and supine. Conclusion: At 70° tilt, HRV measures, reflecting vagal contribution to cardiac-cycle length, decreased with reciprocal increase in sympathetic activity compared to 10° or supine leading to increase in sympathetic predominance. A 10° tilt, which is almost equivalent to lying down with pillow, did not change HRV from supine. Key words: Cardiac cycle; cardiovascular haemodynamics; head-up-tilt; heart rate variability; sympathetic activity; parasympathetic activity DOI: 10.3126/kumj.v7i3.2733 Kathmandu University Medical Journal (2009) Vol.7, No.3 Issue 27, 252-257

Heart Rate Variability Measures During Sinus Rhythm Predict Cycle Length Entropy During Atrial Fibrillation

2008 ◽  
Vol 19 (10) ◽  
pp. 1031-1036 ◽  
Author(s):  
NATHAN M. SEGERSON ◽  
MICHAEL L. SMITH ◽  
STEPHEN L. WASMUND ◽  
ROBERT L. LUX ◽  
MARCOS DACCARETT ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Sinus Rhythm ◽  
Cycle Length

scholarly journals Heart rate fragmentation gives novel insights into non-autonomic mechanisms governing beat-to-beat control of the heart’s rhythm

2020 ◽  
Vol 9 ◽  
pp. 204800402094873
Author(s):  
Irene S Lensen ◽  
Oliver J Monfredi ◽  
Robert T Andris ◽  
Douglas E Lake ◽  
J Randall Moorman
Keyword(s):  
Risk Factors ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Cycle Length ◽  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Clinical Risk Factors ◽  
Sinus Arrhythmia ◽  
Local Dynamics ◽  
Clinical Risk

Objectives To demonstrate how heart rate fragmentation gives novel insights into non-autonomic mechanisms of beat-to-beat variability in cycle length, and predicts survival of cardiology clinic patients, over and above traditional clinical risk factors and measures of heart rate variability. Approach: We studied 2893 patients seen by cardiologists with clinical data including 24-hour Holter monitoring. Novel measures of heart rate fragmentation alongside canonical time and frequency domain measures of heart rate variability, as well as an existing local dynamics score were calculated. A proportional hazards model was utilized to relate the results to survival. Main results: The novel heart rate fragmentation measures were validated and characterized with respect to the effects of age, ectopy and atrial fibrillation. Correlations between parameters were determined. Critically, heart rate fragmentation results could not be accounted for by undersampling respiratory sinus arrhythmia. Increased heart rate fragmentation was associated with poorer survival (p ≪ 0.01 in the univariate model). In multivariable analyses, increased heart rate fragmentation and more abnormal local dynamics (p 0.045), along with increased clinical risk factors (age (p ≪ 0.01), tobacco use (p ≪ 0.01) and history of heart failure (p 0.019)) and lower low- to high-frequency ratio (p 0.022) were all independent predictors of 2-year mortality. Significance: Analysis of continuous ECG data with heart rate fragmentation indices yields information regarding non-autonomic control of beat-to-beat variability in cycle length that is independent of and additive to established parameters for investigating heart rate variability, and predicts mortality in concert with measures of local dynamics, frequency content of heart rate, and clinical risk factors.

scholarly journals Anti-aging effects of long-term space missions, estimated by heart rate variability

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kuniaki Otsuka ◽  
Germaine Cornelissen ◽  
Yutaka Kubo ◽  
Koichi Shibata ◽  
Koh Mizuno ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Space Missions ◽  
Aging Effects
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