propranolol was much more potent at blocking isoproterenol-induced tachycardia ( dose ratio 33.5 +/- 2.5 ) than was even the highest dose ( 750 micrograms/kg/min ) of esmolol ( dose ratio 13.1 +/- 1.0 ) .
C0022245
isoproterenol
C0039231
tachycardia