pericardiacophrenic veins

例句：

1. 1.The heart's pericardium is a thin layer of tissue that surrounds the heart.
   心脏的心肌是一层包围心脏的薄组织。
2. 2. Pericardial effusion occurs when fluid builds up in the heart's pericardium.
   心包积液是指心脏周围的心包内积聚液体。
3. 3. During surgery, doctors often need to remove pericardial effusion for better access to the heart.
   在手术中，医生经常需要移除心包积液以便更好地接近心脏。