And how can body, laid in that white rush, But feel the strange heart beating where it lies?

躺于洁白的灯芯草丛，她的身体，怎能不感到卧倒处心的奇特跳动？

耶鲁公开课 - 现代诗歌课程节选

It occurs because blood flow gets reduced in that blood vessel and so the heart muscle, which is actively beating all the time, needs large quantities of oxygen provided by blood can't get the blood through the vessel.

发病原因是冠状动脉血流量降低,因为心肌搏动永不停歇,随时需要血液供给大量氧气,发病时血液无法正常流过血管

耶鲁公开课 - 生物医学工程探索课程节选