Effects Of The Lower Frequency Limit On Determining High Frequency Power Of Heart Rate Fluctuations

Author(s):  
Sapoznikov ◽  
Luria ◽  
Mahler ◽  
Gotsman
2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Luyi Li ◽  
Dayu Hu ◽  
Wenlou Zhang ◽  
Liyan Cui ◽  
Xu Jia ◽  
...  

Abstract Background The adverse effects of particulate air pollution on heart rate variability (HRV) have been reported. However, it remains unclear whether they differ by the weight status as well as between wake and sleep. Methods A repeated-measure study was conducted in 97 young adults in Beijing, China, and they were classified by body mass index (BMI) as normal-weight (BMI, 18.5–24.0 kg/m2) and obese (BMI ≥ 28.0 kg/m2) groups. Personal exposures to fine particulate matter (PM2.5) and black carbon (BC) were measured with portable exposure monitors, and the ambient PM2.5/BC concentrations were obtained from the fixed monitoring sites near the subjects’ residences. HRV and heart rate (HR) were monitored by 24-h Holter electrocardiography. The study period was divided into waking and sleeping hours according to time-activity diaries. Linear mixed-effects models were used to investigate the effects of PM2.5/BC on HRV and HR in both groups during wake and sleep. Results The effects of short-term exposure to PM2.5/BC on HRV were more pronounced among obese participants. In the normal-weight group, the positive association between personal PM2.5/BC exposure and high-frequency power (HF) as well as the ratio of low-frequency power to high-frequency power (LF/HF) was observed during wakefulness. In the obese group, personal PM2.5/BC exposure was negatively associated with HF but positively associated with LF/HF during wakefulness, whereas it was negatively correlated to total power and standard deviation of all NN intervals (SDNN) during sleep. An interquartile range (IQR) increase in BC at 2-h moving average was associated with 37.64% (95% confidence interval [CI]: 25.03, 51.51%) increases in LF/HF during wakefulness and associated with 6.28% (95% CI: − 17.26, 6.15%) decreases in SDNN during sleep in obese individuals, and the interaction terms between BC and obesity in LF/HF and SDNN were both statistically significant (p <  0.05). The results also suggested that the effects of PM2.5/BC exposure on several HRV indices and HR differed in magnitude or direction between wake and sleep. Conclusions Short-term exposure to PM2.5/BC is associated with HRV and HR, especially in obese individuals. The circadian rhythm of HRV should be considered in future studies when HRV is applied. Graphical abstract


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Vladimir Shusterman ◽  
Jan Nemec ◽  
Marie Buncova ◽  
Bruce Winter ◽  
Win-Kuang Shen ◽  
...  

Background: The hallmark of Long QT Syndrome (LQTS) is a prolongation of the ventricular electrical action potential caused by mutations involving key cardiac ion channels on the surface membrane of ventricular myocytes. Different mutations are associated with specific modes of arrhythmia initiation and distinct changes in cardiac rhythm prior to these events. We hypothesized that some LQTS-causing mutations might involve the sinus node, leading to aberrations in cardiac rhythm. To test this hypothesis, we examined the features of cardiac rhythm in 23 genotyped patients with LQTS and 14 matched controls (C) using Holter ECG data (6hrs). Methods: QRS-complexes were identified using custom software and verified by an experienced ECG reader; series of sinus beats were extracted and gaps in time series were linearly interpolated. The mean, max, and min heart rate (HR), the time (SD, SDNN, SDANN, RMSSD, pNN50) and frequency-domain (Total (TP), Very low (VLF), Low (LF), High (HF) frequency powers, and LF/HF) indices of heart rate variability (HRV) were calculated in each 5-min interval and over the entire recording. The short-long-short irregularity was examined using the novel multiscale rhythmogenetic analysis (MRA), which quantifies changes in the HRV indices during the transition from one time-scale window to another. Results: The maximum heart rate was slower in LQTS than in C (101±13 and 119±19bpm, p=0.001). The high-frequency power (HF) was lower in LQTS than in C (80±76 and 113±58ms 2 , p<0.05). However, the short-term irregularity (quantified by the difference in RMSSD between the 75ms and 2000ms time scales) was 4 times greater in LQTS compared to C (p=0.003). Inclusion or exclusion of two patents who were on β-blockers did not change the results. Conclusions: LQTS is associated with specific changes in cardiac rhythm, including: diminished acceleration capacity, decreased high-frequency power, and enhanced short-long-short irregularity. This suggests that LQTS involves channel modifications in the sinus node, which might contribute to arrhythmogenesis. Rhythm characterization in genetic sub-types of LQTS might improve arrhythmia risk stratification in this heterogeneous patient population.


Author(s):  
Jean Marie Buregeya ◽  
Philippe Apparicio ◽  
Jérémy Gelb

Exposure to traffic-related air pollution and noise exposure contributes to detrimental effects on cardiac function, but the underlying short-term effects related to their simultaneous personal exposure remain uncertain. The aim is to assess the impact of total inhaled dose of particulate matter and total noise exposure on the variations of electrocardiogram (ECG) parameters between pre-cycling and post-cycling periods. Mid-June 2019, we collected four participants’ personal exposure data related to traffic-related noise and particulate matter (PM2.5 and PM10) as well as ECG parameters. Several Bayesian linear models were built to examine a potential association between air pollutants and noise exposure and ECG parameters: heart rate (HR), standard deviation of the normal-to-normal intervals (SDNN), percentage of successive RR intervals that differ by more than 50 ms (pNN50), root mean square of successive RR interval differences (rMSSD), low-frequency power (LF), high-frequency power (HF), and ratio of low- to high-frequency power (LF/HF). We analyzed in total 255 5-min segments of RR intervals. We observed that per 1 µg increase in cumulative inhaled dose of PM2.5 was associated with 0.48 (95% CI: 0.22; 15.61) increase in variation of the heart rate, while one percent of total noise dose was associated with 0.49 (95% CI: 0.17; 0.83) increase in variation of heart rate between corresponding periods. Personal noise exposure was no longer significant once the PM2.5 was introduced in the whole model, whilst coefficients of the latter that were significant previously remained unchanged. Short-term exposure to traffic-related air and noise pollution did not, however, have an impact on heart rate variability.


1996 ◽  
Vol 271 (2) ◽  
pp. H455-H460 ◽  
Author(s):  
K. P. Davy ◽  
N. L. Miniclier ◽  
J. A. Taylor ◽  
E. T. Stevenson ◽  
D. R. Seals

Coronary heart disease (CHD) and cardiac sudden death (CSD) incidence accelerates after menopause, but the incidence is lower in physically active versus less active women. Low heart rate variability (HRV) is a risk factor for CHD and CSD. The purpose of the present investigation was to test the hypothesis that HRV at rest is greater in physically active compared with less active postmenopausal women. If true, we further hypothesized that the greater HRV in the physically active women would be closely associated with an elevated spontaneous cardiac baroreflex sensitivity (SBRS). HRV (both time and frequency domain measures) and SBRS (sequence method) were measured during 5-min periods of controlled frequency breathing (15 breaths/min) in the supine, sitting, and standing postures in 9 physically active postmenopausal women (age = 53 +/- 1 yr) and 11 age-matched controls (age = 56 +/- 2 yr). Body weight, body mass index, and body fat percentage were lower (P < 0.01) and maximal oxygen uptake was higher (P < 0.01) in the physically active group. The standard deviation of the R-R intervals (time domain measure) was higher in all postures in the active women (P < 0.05) as were the high-frequency, low-frequency, and total power of HRV. SBRS also was higher (P < 0.05) in the physically active women in all postures and accounted for approximately 70% of the variance in the high-frequency power of HRV (P < 0.05). The results of the present investigation indicate that physically active postmenopausal women demonstrate higher levels of HRV compared with age-matched, less active women. Furthermore, SBRS accounted for the majority of the variance in the high-frequency power of HRV, suggesting the possibility of a mechanistic link with cardiac vagal modulation of heart rate. Our findings may provide insight into a possible cardioprotective mechanism in physically active postmenopausal women.


2005 ◽  
Vol 33 (01) ◽  
pp. 157-164 ◽  
Author(s):  
Sheng-Teng Huang ◽  
Gau-Yang Chen ◽  
Huey-Ming Lo ◽  
Jaung-Gang Lin ◽  
Yin-Shiung Lee ◽  
...  

Acupuncture at the Neiguan (P6) point has been shown to lessen nausea and vomiting which are related to vagal modulation. This study investigated whether acupuncture at the P6 point could improve vagal modulation by using heart rate variability analysis. We compared the heart rate variability measures of 39 subjects receiving acupuncture at the P6 point, 38 subjects receiving sham acupuncture, and 34 subjects receiving no treatment at all. The normalized high-frequency power was used as the index of vagal modulation, and the low-/high-frequency power ratio was used as the index of sympathovagal balance. The normalized high-frequency power after acupuncture increased significantly from 28.1±12.6 nu (mean±SD) to 30.7±14.1 nu in the P6 acupuncture group, but not in the sham acupuncture (30.6±13.7 nu versus 31.8±13.8 nu) or no-treatment group (30.1±15.0 nu versus 30.1±15.7 nu). In both the P6 and sham acupuncture groups, the mean RR interval (the intervals between consecutive R waves in the electrocardiogram) increased significantly after acupuncture. In the no-treatment group, there was no statistical difference in all heart rate variability measures in the initial and later sessions. In conclusion, acupuncture at the P6 point can increase vagal modulation of the subjects. This result may be helpful in the understanding of the mechanism underlying the effect of acupuncture or acupressure at P6 on the lessening of nausea and vomiting in clinic.


2006 ◽  
Vol 31 (3) ◽  
pp. 277-282 ◽  
Author(s):  
Katharine E Reed ◽  
Darren E.R Warburton ◽  
Crystal L Whitney ◽  
Heather A McKay

Heart rate variability (HRV) is an umbrella term for a variety of measures that assess autonomic influence on the heart. Reduced beat-to-beat variability is found in individuals with a variety of cardiac abnormalities. A reduced HRV positively correlates with obesity, poor aerobic fitness, and increasing age. Racial (black-white) differences are apparent in adults and adolescents. We aimed to evaluate (i) Asian-Caucasian differences in HRV and (ii) differences in HRV between girls and boys. Sixty-two children (30 male (15 Caucasian, 15 Asian) and 32 female (15 Caucasian, 17 Asians)) with a mean age of 10.3 ± 0.6 y underwent 5 min resting HRV recording, fitness testing (Leger's 20 m shuttle), and self-assessed maturity. Outcome HRV measures were a ratio of low to high frequency power (LF:HF), standard deviation of R-R intervals (SDRR) and root mean square of successive R-R intervals (RMSSD). Data were compared between groups using analysis of covariance (ANCOVA). There were no race or sex differences for time domain variables, mean R-R, body mass index, or blood pressure. Compared with Caucasian children, Asian children displayed a higher adjusted (fitness, R-R interval) LF:HF ratio (72.9 ± 59.4 vs. 120.6 ± 85.3, p < 0.05). Girls demonstrated a higher adjusted LF:HF power than boys (117.2 ± 85.1 vs. 76.6 ± 62.4, p = < 0.05). In conclusion, Asian and Caucasian children display different frequency domain components of heart rate variability.Key words: autonomic nervous system, sympathetic, vagal, race, aerobic fitness, sex.


2003 ◽  
Vol 95 (4) ◽  
pp. 1394-1404 ◽  
Author(s):  
Anna Blasi ◽  
Javier Jo ◽  
Edwin Valladares ◽  
Barbara J. Morgan ◽  
James B. Skatrud ◽  
...  

We performed time-varying spectral analyses of heart rate variability (HRV) and blood pressure variability (BPV) recorded from 16 normal humans during acoustically induced arousals from sleep. Time-varying autoregressive modeling was employed to estimate the time courses of high-frequency HRV power, low-frequency HRV power, the ratio between low-frequency and high-frequency HRV power, and low-frequency power of systolic BPV. To delineate the influence of respiration on HRV, we also computed respiratory airflow high-frequency power, the modified ratio of low-frequency to high-frequency HRV power, and the average transfer gain between respiration and heart rate. During cortical arousal, muscle sympathetic nerve activity and heart rate increased and returned rapidly to baseline, but systolic blood pressure, the ratio between low-frequency and high-frequency HRV power, low-frequency HRV power, the modified ratio of low-frequency to high-frequency HRV power, and low-frequency power of systolic BPV displayed increases that remained above baseline up to 40 s after arousal. High-frequency HRV power and airflow high-frequency power showed concommitant decreases to levels below baseline, whereas the average transfer gain between respiration and heart rate remained unchanged. These findings suggest that 1) arousal-induced changes in parasympathetic activity are strongly coupled to respiratory pattern and 2) the sympathoexcitatory cardiovascular effects of arousal are relatively long lasting and may accumulate if repetitive arousals occur in close succession.


Sign in / Sign up

Export Citation Format

Share Document