We compared the haemodynamic effects of epinephrine 10 micrograms/kg iv (group A, n = 8) and 50 micrograms/kg iv (group B, n = 8) in a porcine CPR-model after 3 min of circulatory arrest induced by ventricular fibrillation. All animals of group A were successfully resuscitated after 4.9 +/- 2.8 min and 2.8 +/- 1.6 defibrillations, in group B only 6 of 8 animals were successfully resuscitated after 6.3 +/- 1.1 min and 4.0 +/- 2.7 defibrillations (Mean +/- SD). Cardiac output, left ventricular systolic pressure and mean arterial pressure during CPR were nearly identical in both groups. The first hour of restored spontaneous circulation in group B was characterised by a significantly increased heart rate combined with significantly lower values for cardiac inotropy, cardiac output, left ventricular systolic pressure and mean arterial pressure. It is concluded that in acute or short-term cardiac arrest the currently recommended epinephrine dosages are sufficient. Higher doses of epinephrine for CPR seem to be recommendable only after prolonged cardiac arrest and/or during prolonged resuscitation.