Continuous, on-line, real-time spectral analysis of systemic arterial
pressure signals during cardiopulmonary bypass.
Yang, M. W., Terry B. J. Kuo, S. M. Lin, K. H. Chan, and Samuel H. H. Chan.
Department of Anesthesiology and Institute of Pharmacology, National Yang
-Ming University, Taipei 11221 and Veterans General Hospital-Taipei, Taipei
11217, Taiwan, Republic of China
APStracts 2:0007H, 1995.
We communicated the application of continuous, on-line and real-time power
spectral analysis of systemic arterial pressure (SAP) signals during
cardiopulmonary bypass when the heart was func tionally but reversibly
disconnected from the blood vessels. Based on observations from 15 cases of
successfully completed coronary artery bypass grafting procedures, we found
that the very low (0.00-0.08Hz), low (0.08-0.15 Hz), high (0.15-0.25 Hz) and
very high (0.80-1.60 Hz) frequency components of SAP signals exhibited
differential changes before, during and after cardiopulmonary bypass. In
particular, the very low frequency component, which purportedly represents
the contribution of vasomotor activity to SAP, presented only a mild decrease
in power during hypothermic cardioplegia. Interestingly, the total peripheral
resist ance also manifested only a slight reduction during the same period.
On the other hand, the low, high and very high frequency components were
essentially eliminated. These results unveiled an active role for the blood
vessels in the maintenance of SAP during cardiopulmonary bypass, possi bly as
a result of a maintained vasomotor tone as reflected by the sus tained very
low frequency component of the SAP signals.
Received 21 June 1994; accepted in final form 7 January 1995.
APS Manuscript Number H549-4.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 24 February 1995.