Ramus nodi sinuatrialis

例句：

1. 1.He was in a state of shock when he heard the news about his grandfather's sudden death.
   当他听到祖父突然去世的消息时，他处于一种震惊状态。
2. 2.The doctor advised him to rest and monitor his heart rate regularly.
   医生建议他休息并定期监测他的心率。
3. 3. During his recovery, he had to learn to control his rapid heart rate.
   在他康复期间，他必须学会控制他的快速心率。