Improved ventricular function during inhalation of PGI(2) aerosol partly relies on enhanced myocardial contractility

Inhaled prostacyclin (PGI(2)) 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 PGI(2) analogs epoprostenol (EPO) and
iloprost (ILO) on RV function and myocardial contractility in 9
anesthetized pigs receiving aerosolized EPO (25 and 50 ng center
dot kg(-1) center dot min(-1)) and, consecutively, ILO (60 ng
center dot kg(-1) center dot 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, E-es). EPO and
ILO reduced PAP, increased RVEF and reduced RVEDV. E-es was
enhanced during all doses tested, which reached statistical
significance during EPO25ng and ILO, but not during EPO50ng. PGI(2)
aerosol enhances myocardial contractility in healthy pigs,
contributing to improve RV function. Copyright (C) 2005 S. Karger
AG, Basel.