Cardiac and microcirculatory effects of different doses of prostaglandin E1 in man

Summary A cumulative dose response to intravenous PGE₁ was established in 12 healthy volunteers. Systolic time intervals, including pre-ejection period (PEP), the ventricular ejection time (VET) and the RR-interval, were continuously determined, and transcutaneous oxygen pressure (tcpO₂) was recorded.RR-intervals fell in a dose dependent manner, reaching a significantly lower level at 128 ng·kg^–1·min^–1 of PGE₁ (basal value 842 ms falling to 756 ms). PEP decreased from 89 ms to 74 ms and the ratio PEP/VET decreased from 35% to 30%, indicating increased myocardial contractility. The maximal increase in tcpO₂ was 125% on the calf and 60% on the foot. The peak tcpO₂ was observed at an infusion rate of 16 ng·kg^–1·min^–1 PGE₁. A decline in tcpO₂ was seen at infusion rates >64 ng·kg^–1·min^–1 PGE₁, indicating a decrease in skin perfusion.The results indicate that the effects of intravenous PGE₁ on skin perfusion occur at a lower threshold than the increase in myocardial contractility. A maximal increase in skin perfusion can be achieved with doses of PGE₁ devoid of systemic haemodynamic effects.