Development of heart rate in the precocial king quail Coturnix chinensis.

1998 ◽  
Vol 201 (7) ◽  
pp. 931-941 ◽  
Author(s):  
J T Pearson ◽  
M Tsudzuki ◽  
Y Nakane ◽  
R Akiyama ◽  
H Tazawa

Our aim was to examine changes in heart rate (fh) during the embryonic and posthatching periods of the smallest precocial avian species, Coturnix chinensis. In experiment I, repeated measurements of mean fh were made for individual quail by ballistocardiogram (BCG) during incubation, and by both piezo-electric film and electrocardiogram (ECG) during the posthatching period (resting and thermoneutral conditions). Mean fh of all embryos increased during the second half of incubation and the first week posthatching, but a few embryos experienced a very brief period of decreased fh prior to internal pipping. After the first week, fh of posthatching quail was maintained at high levels (550-650 beats min-1), then decreased with age and increase in body mass. The maximal fh of quail chicks represents a greater posthatching increase in fh than is found in larger precocial chickens, this difference being attributable to the higher demands of thermoregulation at small body masses in the quail. In experiment II, the mean fh of quail embryos (day 2-16) was recorded by ECG, and embryonic stage, yolk-free embryo mass (wet and dry) and water content were measured. Mean fh was linearly related to embryo mass throughout incubation, except on the day prior to internal pipping, when the fh of a few embryos declined below this linear relationship. Measurements of instantaneous fh of late incubation embryos, young and adult quail all showed spontaneous fluctuations in fh. Two main frequency components of fh fluctuations were identified for the first time in an avian species. Low-frequency (mean 0.09 Hz, 12.6 s) and high-frequency (1.4 Hz, 0.9 s) oscillations in both young chicks and adult quail were detected and are considered to reflect baroreflex mediation of fh and respiratory sinus arrhythmia, respectively.

2003 ◽  
Vol 284 (6) ◽  
pp. H1995-H2006 ◽  
Author(s):  
P-F. Migeotte ◽  
G. Kim Prisk ◽  
M. Paiva

We studied heart rate (HR), heart rate variability (HRV), and respiratory sinus arrhythmia (RSA) in four male subjects before, during, and after 16 days of spaceflight. The electrocardiogram and respiration were recorded during two periods of 4 min controlled breathing at 7.5 and 15 breaths/min in standing and supine postures on the ground and in microgravity. Low (LF)- and high (HF)-frequency components of the short-term HRV (≤3 min) were computed through Fourier spectral analysis of the R-R intervals. Early in microgravity, HR was decreased compared with both standing and supine positions and had returned to the supine value by the end of the flight. In microgravity, overall variability, the LF-to-HF ratio, and RSA amplitude and phase were similar to preflight supine values. Immediately postflight, HR increased by ∼15% and remained elevated 15 days after landing. LF/HF was increased, suggesting an increased sympathetic control of HR standing. The overall variability and RSA amplitude in supine decreased postflight, suggesting that vagal tone decreased, which coupled with the decrease in RSA phase shift suggests that this was the result of an adaptation of autonomic control of HR to microgravity. In addition, these alterations persisted for at least 15 days after return to normal gravity (1G).


2016 ◽  
Vol 28 (06) ◽  
pp. 1650039
Author(s):  
Pei-Chen Lo ◽  
Wu Jue Miao Tian

Innovatively new behaviors of heart rate variability caused by special heart-transition process were observed in the long-term, well-experienced Zen practitioners while practicing the heart-to-heart imprint sealing (HHIS) Zen meditation. HHIS Zen practice involves specific neurocardiac-cardiorespiratory interaction while on the way of realizing the heart-dominant, detached brain. Results of analyzing the electrocardiogram and respiratory signals of 10 experienced practitioners reveal several distinctive characteristics: (1) remarkably linear correlation between standard deviation of the normal R-to-R intervals, SDNN, and total power in very-low-frequency (VLF, 0.0033–0.04[Formula: see text]Hz) band of power spectrum of the heart-rate sequence, (2) time-varying VLF power dominating over the low-frequency and high-frequency power in heart rate variability (HRV) variations, (3) intermittent transition into slowly, deeply abdominal respiration inducing a boost of heart rates, (4) heart-rate baseline slowly fluctuating at 0.005–0.0067[Formula: see text]Hz, about 1.5–2 cycles in 5-min period, and (5) remarkable respiratory sinus arrhythmia (RSA) synchrony between heart rate and respiration rhythm. This paper proposes a rational scientific hypothesis for the neurocardiac-cardiorespiratory mechanism. The unique scheme of HHIS Zen meditation involves the spiritual-qi concentration and refinement for pinpointing into the particular energy centers, mailuns. Ignition by a subtle, deepest abdominal respiration, electrical impulses rapidly transmit from solar plexus to branchial plexuses to activate unique heart-transition process. Simultaneously, another branch streams upward the spinal cord to cervical plexus and brainstem that effectively harmonizes neurocardiac interactions. To investigate the underlying behaviors, time-domain and frequency-domain HRV based on continuous wavelet transform were employed.


2015 ◽  
Vol 33 (1) ◽  
pp. 30-35 ◽  
Author(s):  
Huanlin Huang ◽  
Zheng Zhong ◽  
Junqi Chen ◽  
Yong Huang ◽  
Jixuan Luo ◽  
...  

Objective To explore the effect of acupuncture at HT7 on heart rate variability (HRV) in healthy volunteers. Methods 120 subjects were divided into four groups using a random number table. The following groups of acupuncture interventions were used: HT7 verum acupuncture; HT7 non-penetrating sham acupuncture; acupuncture at a sham point; and no acupuncture. HRV was recorded 10 min before, during and after each stimulation using an Actiheart ECG recorder. Results The HT7 verum acupuncture group had higher very-low frequency, low frequency and high frequency components of HRV compared with the control groups during but not after acupuncture. The HT7 verum acupuncture group also had higher SD of normal intervals compared with the sham needling and no acupuncture control groups. Conclusions Our preliminary study suggests, subject to limitations, that acupuncture at HT7 could affect cardiac autonomic neural regulation in healthy subjects, manifest as increased HRV, most likely via the parasympathetic system. Trial Registration Number ChiCTR-TRC-08000302.


2021 ◽  
Author(s):  
Jacek Kolacz ◽  
Elizabeth B daSilva ◽  
Gregory F Lewis ◽  
Bennett I Bertenthal ◽  
Stephen W Porges

Caregiver voices may provide cues to mobilize or calm infants. This study examined whether maternal prosody predicted changes in infants' biobehavioral state during the Still Face, a stressor in which the mother withdraws and reinstates social engagement. Ninety-four dyads participated in the study (infant age 4-8 months). Infants' heart rate and respiratory sinus arrhythmia (measuring cardiac vagal tone) were derived from an electrocardiogram (ECG). Infants' behavioral distress was measured by negative vocalizations, facial expressions, and gaze aversion. Mothers' vocalizations were measured with spectral analysis and spectro-temporal modulation using a two-dimensional fast Fourier transformation of the audio spectrogram. High values on the maternal prosody composite were associated with decreases in infants' heart rate (β=-.26, 95% CI: [-.46, -.05]) and behavioral distress (β=- .20, 95% CI: [-.38, -.02]), and increases in cardiac vagal tone in infants whose vagal tone was low during the stressor (1 SD below mean β=.39, 95% CI: [.06, .73]). High infant heart rate predicted increases in the maternal prosody composite (β=.18, 95% CI: [.03, .33]). These results suggest specific vocal acoustic features of speech that are relevant for regulating infants' biobehavioral state and demonstrate mother-infant bi-directional dynamics.


2018 ◽  
pp. 695-702 ◽  
Author(s):  
M. VETERNIK ◽  
I. TONHAJZEROVA ◽  
J. MISEK ◽  
V. JAKUSOVA ◽  
H. HUDECKOVA ◽  
...  

Previous studies of physiological responses to music and noise showed the effect on the autonomic nervous system. The heart rate variability (HRV) has been used to assess the activation of the sympathetic and the parasympathetic nervous systems. The present study was aimed to examine HRV with exposure to four sine-wave pure tones (20 Hz, 50 Hz, 2 kHz and 15 kHz) in an environment where the sound intensity exceeded level 65 dB (A-weighted). The participants (20 adolescent girls) were lying in supine position during exposure protocol divided into 6 periods, the first time with generated sounds and the second time without sounds. In the protocol without sound exposure, the low frequency band of the HRV spectrum was increased compared to the basal state before examination (period_1: 6.05±0.29 ms2 compared to period_5: 6.56±0.20 ms2, p<0.05). The significant increase of root Mean Square of the Successive Differences (rMSSD, period_1: 4.09±0.16 s compared to period_6: 4.33±0.12 s, p<0.05) and prolongation of R to R peak (RR) interval (period_1: 889±30 ms compared to period_5: 973±30 ms, p<0.001) were observed in the protocol without sound exposure comparing to the protocol with sound exposure where only bradycardia was observed. Contrary to rather polemical data in literature our pilot study suggests that sounds (under given frequencies) have no impact on the heart rate variability and cardiac autonomic regulation.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yoshie Nakajima ◽  
Naofumi Tanaka ◽  
Tatsuya Mima ◽  
Shin-Ichi Izumi

Sounds can induce autonomic responses in listeners. However, the modulatory effect of specific frequency components of music is not fully understood. Here, we examined the role of the frequency component of music on autonomic responses. Specifically, we presented music that had been amplified in the high- or low-frequency domains. Twelve healthy women listened to white noise, a stress-inducing noise, and then one of three versions of a piece of music: original, low-, or high-frequency amplified. To measure autonomic response, we calculated the high-frequency normalized unit (HFnu), low-frequency normalized unit, and the LF/HF ratio from the heart rate using electrocardiography. We defined the stress recovery ratio as the value obtained after participants listened to music following scratching noise, normalized by the value obtained after participants listened to white noise after the stress noise, in terms of the HFnu, low-frequency normalized unit, LF/HF ratio, and heart rate. Results indicated that high-frequency amplified music had the highest HFnu of the three versions. The stress recovery ratio of HFnu under the high-frequency amplified stimulus was significantly larger than that under the low-frequency stimulus. Our results suggest that the high-frequency component of music plays a greater role in stress relief than low-frequency components.


1981 ◽  
Vol 241 (4) ◽  
pp. H620-H629 ◽  
Author(s):  
J. A. Hirsch ◽  
B. Bishop

The relationship of respiratory sinus arrhythmia amplitude (RSA) to tidal volume and breathing frequency was quantified during voluntarily controlled tidal volume and breathing frequency and spontaneous quiet breathing. Seventeen seated subjects breathed via mouthpiece and nose-clip, maintaining constant tidal volumes at each of several breathing frequencies. Inspiratory breath hold was zero frequency. Log RSA was plotted vs. log frequency for each tidal volume. The large stable RSA for frequencies less than 6 cycles/min was called low-frequency intercept (LFI, 20 +/- 5 beats/min). Low-frequency intercept was inversely proportional to a subject's age only to 35 yr. At higher breathing frequencies above a characteristic corner frequency (fC, 7.2 +/- 1.5 cycles/min) RSA decreased with constant slope (roll-off; 21 +/- 3.4 dB/decade). The RSA-volume relationship was linear permitting normalization of RSA-frequency curves for tidal volume to yield one curve. Spontaneous breathing data points fell on this curve. Voluntarily coupling of heart rate to breathing frequency in integer ratios reduced breath-by-breath variability of RSA without changing mean RSA. In conclusion, low-frequency intercept, corner frequency, and roll-off characterize an individual's RSA-frequency relationship during both voluntarily controlled and spontaneous breathing.


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