The presence of a substance with positive inotropic activity in blood plasma of a variety of animals.
D000818:Animals; D001001:Anura; D002850:Chromatography, Gel; D004285:Dogs; D004524:Eels; D005399:Fishes; D006168:Guinea Pigs; D000882:Haplorhini; D006321:Heart / Q000187:drug effects*; D006801:Humans; D010949:Plasma; D011200:Poultry; D011817:Rabbits; D051381:Rats; D012104:Reptiles