THE PERICARDIUM FACILITATES PRESSURE WORK IN THE EEL HEART

An in siru perfused eel Anguilla dieffenbachü Gray 1842) heart was used to investigate the role of the pericardium in cardiac function. Hearts with intact pericardia were compared with hearts in which the pericardia were either punctured or opened completely. Cardiac function was assessed at low and high adrenaline levels by determining: maximum cardiac output; maximum sustainable output pressure; power output under maximal filling and output pressures; and maximum power output. Puncturing a small hole in the pericardium equalizing ambient and intrapericardial pressures had little effect on cardiac function and performance. Opening the pericardium, thereby fully exposing the chambers of the heart, severely limited the heart's ability to do pressure work. This effect was reversed at high adrenaline concentrations. Flow related work, and maximum power output levels were maintained after opening the pericardium. Copyright © 1991, Wiley Blackwell. All rights reserved