Changes in myocardial fluid filtration are reflected in epicardial lymph pressure. Vanteeffelen, Jurgen W. G. E., Daphne Merkus, Isabelle Vergroesen, and Jos A. E. Spaan. Department of Medical Physics, Cardiovascular Research Institute Amsterdam, Academic Medical Center, University of Amsterdam, PO Box 22700, 1100 DE Amsterdam, the Netherlands
APStracts 3:0382H, 1996.
The effect of an increased fluid filtration on stopped-flow epicardial lymph pressure (Plymph), used as indicator of myocardial interstitial volume, was investigated in the anaesthetized open-chest dog. Histamine infusion resulted in an increased systolic peak in the Plymph signal together with an increase in diastolic Plymph in 4 of 5 animals. During reactive hyperemia systolic and diastolic Plymph increased to respectively 127+/-8 (SEM; n=6) and 121+/-6.7% of control. Peak Plymph was about 15 s later than peak coronary blood flow and venous pressure (Pven). When Pven was transiently elevated to 367+/-72 (systolic) and 247+/-45% (diastolic) of control, Plymph increased to 132+/-12 and 120+/-5.5% of control. The time of response was similar for Pven and Plymph (t50 nearly equal to 2s). The increased systolic and diastolic Plymph can be explained by an increased interstitial and lymph filling. It is concluded that changes in myocardial fluid filtration are reflected in epicardial lymph pressure. Furthermore, it seems that cardiac contraction constitutes an important defense mechanism against the formation of myocardial edema.

Received 6 May 1996; accepted in final form 21 August 1996.
APS Manuscript Number H400-6.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 19 September 1996