AJP - Heart and Circulatory Physiology, Vol 261, Issue 4 1231-H1245, Copyright © 1991 by American Physiological Society

ARTICLES

Transfer function analysis of the circulation: unique insights into cardiovascular regulation

J. P. Saul, R. D. Berger, P. Albrecht, S. P. Stein, M. H. Chen and R. J. Cohen
Harvard-Massachusetts Institute of Technology, Division of Health Sciences and Technology, Cambridge 02139.

We have demonstrated previously that transfer function analysis can be used to precisely characterize the respiratory sinus arrhythmia (RSA) in normal humans. To further investigate the role of the autonomic nervous system in RSA and to understand the complex links between respiratory activity and arterial pressure, we determined the transfer functions between respiration, heart rate (HR), and phasic, systolic, diastolic, and pulse arterial pressures in 14 healthy subjects during 6-min periods in which the respiratory rate was controlled in a predetermined but erratic fashion. Pharmacological autonomic blockade with atropine, propranolol, and both, in combination with changes in posture, was used to characterize the sympathetic and vagal contributions to these relationships, as well as to dissect the direct mechanical links between respiration and arterial pressure from the effects of the RSA on arterial pressure. We found that 1) the pure sympathetic (standing + atropine) HR response is characterized by markedly reduced magnitude at frequencies greater than 0.1 Hz and a phase delay, whereas pure vagal (supine + propranolol) modulation of HR is characterized by higher magnitude at all frequencies and no phase delay; 2) both the mechanical links between respiration and arterial pressure and the RSA contribute significantly to the effects of respiration on arterial pressure; 3) the RSA contribution to arterial pressure fluctuations is significant for vagal but not for sympathetic modulation of HR; 4) the mechanical effects of respiration on arterial pressure are related to the negative rate of change of instantaneous lung volume; 5) the mechanical effects have a higher magnitude during systole than during diastole; and 6) the mechanical effects are larger in teh standing than the supine position. Most of these findings can be explained by a simple model of circulatory control based on previously published experimental transfer functions from our laboratory.

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				T. G. Robinson, M. James, J. Youde, R. Panerai, and J. Potter Cardiac Baroreceptor Sensitivity Is Impaired After Acute Stroke Stroke, September 1, 1997; 28(9): 1671 - 1676. [Abstract] [Full Text]

				L. A. Lipsitz, R. Morin, M. Gagnon, D. Kiely, and A. Medina Vasomotor instability preceding tilt-induced syncope: does respiration play a role? J Appl Physiol, August 1, 1997; 83(2): 383 - 390. [Abstract] [Full Text] [PDF]

				M. Piepoli, P. Sleight, S. Leuzzi, F. Valle, G. Spadacini, C. Passino, J. Johnston, and L. Bernardi Origin of Respiratory Sinus Arrhythmia in Conscious Humans : An Important Role for Arterial Carotid Baroreceptors Circulation, April 1, 1997; 95(7): 1813 - 1821. [Abstract] [Full Text]

				J. Hayano, F. Yasuma, A. Okada, S. Mukai, and T. Fujinami Respiratory Sinus Arrhythmia: A Phenomenon Improving Pulmonary Gas Exchange and Circulatory Efficiency Circulation, August 15, 1996; 94(4): 842 - 847. [Abstract] [Full Text]

				O. Tochikubo, A. Ikeda, E. Miyajima, and M. Ishii Effects of Insufficient Sleep on Blood Pressure Monitored by a New Multibiomedical Recorder Hypertension, June 1, 1996; 27(6): 1318 - 1324. [Abstract] [Full Text]

				J. A. Taylor and D. L. Eckberg Fundamental Relations Between Short-term RR Interval and Arterial Pressure Oscillations in Humans Circulation, April 15, 1996; 93(8): 1527 - 1532. [Abstract] [Full Text]

				T. F. o. t. E. S. o. C. t. N. A. S. o. P. Electrophysiology Heart Rate Variability : Standards of Measurement, Physiological Interpretation, and Clinical Use Circulation, March 1, 1996; 93(5): 1043 - 1065. [Full Text]

				L. Bernardi, B. Bianchini, G. Spadacini, S. Leuzzi, F. Valle, E. Marchesi, C. Passino, A. Calciati, M. Vigano, M. Rinaldi, et al. Demonstrable Cardiac Reinnervation After Human Heart Transplantation by Carotid Baroreflex Modulation of RR Interval Circulation, November 15, 1995; 92(10): 2895 - 2903. [Abstract] [Full Text]

				G. Parati, J. P. Saul, M. Di Rienzo, and G. Mancia Spectral Analysis of Blood Pressure and Heart Rate Variability in Evaluating Cardiovascular Regulation : A Critical Appraisal Hypertension, June 1, 1995; 25(6): 1276 - 1286. [Abstract] [Full Text]

				R. L. Hughson, A. Maillet, G. Dureau, Y. Yamamoto, and C. Gharib Spectral Analysis of Blood Pressure Variability in Heart Transplant Patients Hypertension, April 1, 1995; 25(4): 643 - 650. [Abstract] [Full Text]

				E. Toledo, I. Pinhas, D. Aravot, Y. Almog, and S. Akselrod Functional restitution of cardiac control in heart transplant patients Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2002; 282(3): R900 - R908. [Abstract] [Full Text] [PDF]