Heart rate and heart rate variability in chicken embryos at the end of incubation

Our immediate goal was to study heart rate variability (HRV) in chicken embryos in the egg. Instantaneous heart rate data were needed for this purpose, and accordingly an ECG recording method in the egg was developed. The aim of this work was to test the hypothesis that autonomic nervous cardiac modulation, as shown from HRV parameters, is present at the end of development and that it reaches a constant value during the last days of incubation. Embryonic chicken heart rate was obtained at the final incubation period (days 19 and 20) from ECG recordings. Tachograms were computed and time‐ and frequency‐domain indices of HRV were determined. No significant differences were found between HRV indices from day 19 and day 20. The power spectra extended in two frequency bands with centre frequency around 0.6–0.7 Hz (low frequency (LF) component), and another around 1.2–1.5 Hz (high frequency (HF) component); the latter was shown to reflect respiratory sinus arrhythmia. A relation between mean RR interval and some HRV parameters (rMSSD, pNN5 and HF power) was shown. HRV results obtained from embryonic chickens, showed the presence of modulation of cardiovascular function by the autonomic nervous system. The results suggested that sympathetic and parasympathetic activities have already reached a constant level at day 19 of incubation. High frequency oscillations (0.78–2.5 Hz) were detected and are considered to reflect respiratory sinus arrhythmia.

[1]  Ivor Mason,et al.  The Avian Embryo , 1999 .

[2]  H Tazawa,et al.  Comparisons between invasive and noninvasive determinations of embryonic heart rate in chickens. , 1994, Comparative biochemistry and physiology. Comparative physiology.

[4]  H. Fujii,et al.  Noncontact measurements of avian embryo heart rate by means of the laser speckle: comparison with contact measurements , 1989, Medical and Biological Engineering and Computing.

[5]  D. Galletly,et al.  Inspiratory timing during anaesthesia: a model of cardioventilatory coupling. , 2001, British journal of anaesthesia.

[6]  W. Burggren,et al.  Cardiac rhythms in prenatal and perinatal emu embryos. , 2002, Comparative biochemistry and physiology. Part A, Molecular & integrative physiology.

[7]  K. Golka,et al.  Breathing and heart rate during experimental solvent exposure of young adults with self-reported multiple chemical sensitivity (sMCS). , 2003, Neurotoxicology.

[8]  H. Tazawa,et al.  Simultaneous acquisition of ECG, BCG, and blood pressure from chick embryos in the egg. , 1989, Journal of applied physiology.

[9]  S. Piha.  Cardiovascular autonomic reflex tests: normal responses and age-related reference values. , 1991, Clinical physiology.

[10]  H. Tazawa,et al.  Development of heart rate in the precocial king quail Coturnix chinensis. , 1998, The Journal of experimental biology.

[11]  R. Boucek,et al.  Initiation of vagal control of heart rate in the embryonic chick , 1966, The Anatomical record.

[12]  W. Burggren,et al.  Cardiovascular regulation during hypoxia in embryos of the domestic chicken Gallus gallus. , 2003, American journal of physiology. Regulatory, integrative and comparative physiology.

[13]  Marek Malik,et al.  Clinical Guide to Cardiac Autonomic Tests , 1998, Springer Netherlands.

[14]  Jan Strackee,et al.  Spectrum of a series of point events, generated by the integral pulse frequency modulation model , 1985, Medical and Biological Engineering and Computing.

[15]  COMPARISONS OF SYMPATHETIC NERVE RESPONSES TO GRADED NECK AND FOREARMISOMETRIC EXERCISE , 1998 .

[16]  J. Altimiras,et al.  Control of blood pressure mediated by baroreflex changes of heart rate in the chicken embryo (Gallus gallus). , 2000, American journal of physiology. Regulatory, integrative and comparative physiology.

[17]  M. Heymann,et al.  Development of Baroreflex Activity in Unanesthetized Fetal and Neonatal Lambs , 1972, Circulation research.

[18]  A. Aubert,et al.  Neurocardiology: the benefits of irregularity. The basics of methodology, physiology and current clinical applications. , 1999, Acta cardiologica.

[19]  S. Malpas.  Neural influences on cardiovascular variability: possibilities and pitfalls. , 2002, American journal of physiology. Heart and circulatory physiology.

[20]  D. Ramaekers,et al.  Effect of long term physical training on heart rate variability , 1996, Computers in Cardiology 1996.

[21]  D. Walker,et al.  Relationship of arterial pressure and heart rate in fetal, new‐born and adult sheep. , 1980, The Journal of physiology.

[22]  Douglas G. Altman,et al.  Statistics with confidence: Confidence intervals and statistical guidelines . , 1990 .

[23]  I Russell,et al.  Statistics--with confidence? , 1991, The British journal of general practice : the journal of the Royal College of General Practitioners.

[24]  M. Kirby,et al.  Development of ANS Innervation to the Avian Heart , 1986 .

[25]  H. Huikuri,et al.  Time domain, geometrical and frequency domain analysis of cardiac vagal outflow: effects of various respiratory patterns. , 2001, Clinical physiology.

[26]  W. Burggren,et al.  Continuous measurements of instantaneous heart rate and its fluctuations before and after hatching in chickens. , 2000, The Journal of experimental biology.

[27]  J. Strackee,et al.  Comparing Spectra of a Series of Point Events Particularly for Heart Rate Variability Data , 1984, IEEE Transactions on Biomedical Engineering.

[28]  H. Tazawa,et al.  Cardiogenic ballistograms of chicken eggs: comparison of measurements , 1991, Medical and Biological Engineering and Computing.

[29]  Hiroshi Tazawa,et al.  Development of heart rate irregularities in chick embryos. , 1998, American journal of physiology. Heart and circulatory physiology.

[30]  R. Cohen,et al.  Power spectrum analysis of heart rate fluctuation: a quantitative probe of beat-to-beat cardiovascular control. , 1981, Science.

[31]  H. Tazawa,et al.  Long-term measurement of heart rate in chicken eggs. , 1999, Comparative biochemistry and physiology. Part A, Molecular & integrative physiology.

[32]  H Ector,et al.  The analysis of heart rate variability in unrestrained rats. Validation of method and results. , 1999, Computer methods and programs in biomedicine.

[33]  T. Sugiyama,et al.  Chick embryos as an alternative experimental animal for cardiovascular investigations: stable recording of electrocardiogram of chick embryos in ovo on the 16th day of incubation. , 1996, Toxicology and applied pharmacology.

[34]  M. Takami,et al.  Simple, noninvasive system for measuring the heart rate of avian embryos and hatchlings by means of a piezoelectric film , 1993, Medical and Biological Engineering and Computing.

[35]  J. Hirsch,et al.  Respiratory sinus arrhythmia in humans: how breathing pattern modulates heart rate. , 1981, The American journal of physiology.

[36]  A. Porta,et al.  Heart rate variability is encoded in the spontaneous discharge of thalamic somatosensory neurones in cat , 2000, The Journal of physiology.

[37]  Robert W. Ramirez,et al.  The Fft, Fundamentals and Concepts , 1984 .

[38]  H. Tazawa,et al.  Embryonic heart rate of the domestic fowl (Gallus domesticus) in a quasiequilibrium state of altered ambient temperatures. , 1992, Comparative biochemistry and physiology. A, Comparative physiology.

[39]  G. Breithardt,et al.  Heart rate variability: standards of measurement, physiological interpretation and clinical use. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. , 1996 .

[40]  A. Pappano,et al.  Ontogenesis of adrenergic and cholinergic neuroeffector transmission in chick embryo heart. , 1974, The Journal of pharmacology and experimental therapeutics.

[41]  B. Linde,et al.  Arachidonic acid metabolism and regulation of blood flow: effect of indomethacin on cutaneous and subcutaneous reactive hyperaemia in humans. , 1983, Clinical Physiology.

[42]  E. Lumbers,et al.  Effect Of Cold On Fetal Heart Rate And Its Variability , 2000, Clinical and experimental pharmacology & physiology.

[43]  H. Tazawa,et al.  Low-frequency oscillation of instantaneous heart rate in newly hatched chicks. , 2002, Comparative biochemistry and physiology. Part A, Molecular & integrative physiology.

[44]  M. Chung,et al.  Stability over time of variables measuring heart rate variability in normal subjects. , 1991, The American journal of cardiology.

[45]  D. Deeming,et al.  Embryonic Heart Rate during Development of Domesticated Birds , 1991, Physiological Zoology.

[46]  Daniel Berckmans,et al.  Noninvasive measurement of heart rate from chicken embryos in the egg , 2000, Computers in Cardiology 2000. Vol.27 (Cat. 00CH37163).

[47]  H. Rahn,et al.  The acoustocardiogram: a noninvasive method for measuring heart rate of avian embryos in ovo. , 1990, Journal of applied physiology.

[48]  R. Cohen,et al.  An Efficient Algorithm for Spectral Analysis of Heart Rate Variability , 1986, IEEE Transactions on Biomedical Engineering.

[49]  A. Malliani,et al.  Heart rate variability. Standards of measurement, physiological interpretation, and clinical use , 1996 .