atrioventricular sequential pacemaker

例句：

1. 1.The patient was successfully implanted with an atrial pacemaker to control his heart rate.
   患者成功地植入了心房起搏器来控制他的心率。
2. 2. During the operation, the surgeon carefully removed the atrial pacemaker and replaced it with a new one.
   手术中，外科医生小心翼翼地移除了心房起搏器并用一个新的替换它。
3. 3.The patient's condition improved significantly after the atrial pacemaker was installed.
   安装心房起搏器后，患者的病情显著改善。