Prostacyclin effect on cardiovascular system in man evaluated by echocardiography

This was an echocardiographic study of the cardiovascular effects of rostacclin (PGI₂) infused intravenously to human volunteers at the rate of 20 ng⊎ Kg⁻ ⊎ min⁻ for 10 Anutes. The following parameters were recorded in the steady state , at one-minute intervals throughout infusion and the ensuing recovery period: systolic, diastolic, and mean blood pressure ( SBP, DBP, MBP); heart rate (HR); left ventricle end-diastolic (EDD) and end-systolic diameter (ESD); stroke volume index ( SVI); cardiac index (CI); peripheral vascular resistance (PVR); left ventricle fractional shortening (FS) and ejection fraction (EF).

We detected a progressive reduction of MBP without any HR modification. MBP reduction was associated with a reduction of PVR and a parallel rise of CI and SVI. There was also an increase of FS and EF reflecting a reduced ESD. We conclude that PGI₂ infused in man at the rate stated above causes hypotension reflecting an arterial vasodilating effect; a lack of heart rate reflex response to afterload reduction (probably a nerve-mediated effect of PGI ); and no venous vasodilation, judging from the absence of any change in end-diastolic diameter.