Improved ventricular function during inhalation of PGI2 aerosol partly relies on enhanced myocardial contractility

Abstract

Inhaled prostacyclin (PGI2) aerosol induces selective pulmonary vasodilation. Further, it improves right ventricular (RV) function, which may largely rely on pulmonary vasodilation, but also on enhanced myocardial contractility. We investigated the effects of the inhaled PGI2 analogs epoprostenol (EPO) and iloprost (ILO) on RV function and myocardial contractility in 9 anesthetized pigs receiving aerosolized EPO (25 and 50 ng·kg-1·min-1) and, consecutively, ILO (60 ng·kg-1·min-1) for 20 min each. We measured pulmonary artery pressure (PAP), RV ejection fraction (RVEF) and RV end-diastolic-volume (RV-EDV), and left ventricular end-systolic pressure-volume-relation (end-systolic elastance, Ees). EPO and ILO reduced PAP, increased RVEF and reduced RVEDV. Ees was enhanced during all doses tested, which reached statistical significance during EPO 25ng and ILO, but not during EPO50ng. PGI2 aerosol enhances myocardial contractility in healthy pigs, contributing to improve RV function. Copyright © 2005 S. Karger AG.