A novel technique for measurement of pericardial pressure.
deVries, Gwyneth, Douglas R. Hamilton, Henk E. D. J. Ter Keurs, Rafael Beyar, and
John V. Tyberg.
Department of Medicine and Department of Physiology and Biophysics, University of
Calgary, Calgary, Alberta, Canada T2N 4N1
APStracts 8:0154H, 2001.
To determine whether pericardial liquid pressure accurately measures pericardial
constraint, we developed a technique in which a catheter was positioned perpendicular to
the epicardial surface. This device, which occupies little or no pericardial space, couples
the thin film of liquid to a transducer. In six open-chest dogs, we also measured left
ventricular (LV) end-diastolic pressure (LVEDP) and anteroposterior and septum-to-free
wall diameters. LVEDP was raised incrementally to ~25 mmHg by saline infusion. With
the use of the product of the two diameters as an index of area (ALV), LVEDP-ALV
relationships were obtained with the pericardium closed and again after the pericardium
had been widely opened to obtain the isovolumic difference in LVEDP (?LVEDP). In all
dogs, the technique yielded values of pericardial pressure equal to ?LVEDP as well as
equal to that measured using a previously placed balloon transducer in the same location
and at the same ALV. We conclude that, when the pressure of the pericardial liquid is
appropriately measured, it (in addition to the balloon-measured contact stress) defines the
diastolic constraining effect of the pericardium. Furthermore, we suggest that earlier
measurements of pericardial "liquid pressure" were low, due to an artifact of
measurement.
Received 29 June 2000; accepted in final form 17 January 2001
APS Manuscript Number H602-0.
Article publication pending Am J Physiol Heart Circ Physiol
ISSN 1080-4757 Copyright 2001 The American Physiological Society.
Published in APStracts on 29 March 2001