fourth heart sound

例句：

1. 1. The doctor listenedto the patient's chest and heardthe fourth heart sound.
   医生听了病人的胸部，听到了第四心音。
2. 2. During surgery, the surgeon carefully monitored the fourth heartsound to ensure proper blood flow.
   在手术过程中，外科医生仔细监测第四心音，以确保血液流动正常。
3. 3. The patientwas in critical condition, and the fourthheart sound was a concern for the medicalteam.
   患者情况危急，第四心音成为医疗团队关注的问题。