The Effect of the Transient Rise in Intrathoracic Pressure on Cardio-Pulmonary Dynamics

Abstract

The cardiovascular dynamics of 13 cases with cardiac or pulmonary disease were studied during the transient rise in the intrathoracic pressure by Valsalva maneuver. The results were as follows.
1) The rise in pressure of the right ventricule, pulmonary artery, right atrium and left atrium were parallel with the rise in intrathoracic pressure.
2) The right ventricular ejection time decreased when the intrathoracic pressure rose. This finding suggested that the right ventricular output was reduced by the decrease of systemic venous return during the rise in intrathoracic pressure, and it had no relation to the increase of pulmonary peripheral resistance.
3) From these findings, it was suggested that Valsalva maneuver or cough might exert no pressure load or work load upon the right ventricule.