text: β<sub>1</sub>受体激动剂可增加心肌收缩力、心率和房室节传导速度，而β<sub>2</sub>受体激动剂则主要分布在支气管上，因而选择性高的β<sub>2</sub>受体激动剂对心脏的不良反应就会明显减少。
entities.entity: β<sub>1</sub>受体激动剂
entities.label: dru
entities.entity: 心肌
entities.label: bod
entities.entity: 心率
entities.label: ite
entities.entity: 房室节传导速度
entities.label: ite
entities.entity: β<sub>2</sub>受体激动剂
entities.label: dru
entities.entity: 支气管
entities.label: bod
entities.entity: β<sub>2</sub>受体激动剂
entities.label: dru
entities.entity: 心脏
entities.label: bod