subendocardial layer

例句：

1. 1. The patient's heart rate was monitored during the procedure.
   在手术过程中，患者心率被监测。
2. 2. The study found that the subendocardial layer plays a crucial role in heart function.
   研究发现，心室下壁层在心脏功能中起着至关重要的作用。
3. 3. The pathologist examined the tissue samples to determine the cause of the patient's heart failure.
   病理学家检查了组织样本，以确定病人心脏病衰竭的原因。