graded tachycardia was induced by raising the stimulus frequency of cardiac sympathetic nerve stimulation stepwise from 1 to 3 and 5 and 10 hz , and it was also induced by norepinephrine infusion ( 0.3-10 micrograms/min into the right coronary artery ) , isoproterenol infusion ( 0.1 and 0.3 micrograms/kg/min i.v . ) and glucagon injection ( 3-30 micrograms/kg i.v . ) .
C0039231
tachycardia
C0022245
isoproterenol