[Pharmacologic action profile of crataegus extract in comparison to epinephrine, amirinone, milrinone and digoxin in the isolated perfused guinea pig heart].

Using isolated perfused guinea pig hearts experiments were performed to investigate the influence of crataegus extract LI 132 (Faros 300, CRA) in comparison to other inotropic drugs--epinephrine (adrenaline, ADR), amrinone (AM), milrinone (MIL) and digoxin (DIG)--on different functional parameters, with special emphasis on the effective refractory period of the myocardium. The simultaneous registration of appropriate parameters allowed to relate the effect on the refractory period to the inotropic, chronotropic, dromotropic and coronary actions of these compounds at each concentration level. All substances--with the exception of CRA--shortened the effective refractory period concentration-dependently besides their known other functional effects (max.: 1 x 10(-5) mol/l ADR by 38%, 7 x 10(-7) mol/l DIG by 26%, 1 x 10(-4) mol/l MIL by 13% and 5 x 10(-4) mol/l AM by 1.6%). Related to the positive inotropy the shortening was most effective under MIL (1.32 ms/mN), followed by AM (0.65 ms/mN), DIG (0.40 ms/mN) and ADR (0.28 ms/mN). On the contrary, CRA produced a prolongation of the effective refractory period by maximally 10% resp. by 2.54 ms/mN. Thus, the pharmacologic profile of CRA differs from that of other inotropic compounds mainly in this parameter (with potentially reduced arrhythmogenic risk).