continuous intravenous infusion of isoproterenol at 0.01 , 0.02 , and 0.03 microgram/kg/min into 12 euthyroid normotensive adult volunteers for 10-min intervals resulted in decreases of 55 , 79 , and 89 msec in qkd and increases of heart rate of 14 , 27 , and 43 beats/min , respectively .
C0022245
isoproterenol
C0039231
increases