Amidine derivatives and cardiotonic containing

DERIVATIVES AMIDINE ANSWERING THE FORMULA: (CF DRAWING IN BOPI) WHERE R and R, WHICH CAN BE IDENTICAL OR DIFFERENT EACH REPRESENT A HYDROGEN ATOM OR GROUP lOWER ALKYL UNLESS R AND R DO FORM SET CYCLE WITH CARBON ATOM INTERMEDIATE ETOU A hETEROATOM; X REPRESENTS OR CH-Z-