[Effect of negative intrathoracic pressure on venous return]

Abstract

In acute experiments on cats and in observations made in human subjects, an increase of the negative intrathoracic pressure (NIP) leads to no significant changes of the venous return (VR) mean values. The peak values of the VR, however, increased and decreased more in inspiration and expiration following a deep breathing as compared with the normal breathing. The NIP seems to exert no direct effect upon the VR.