纵向

He will not take that lying down.

对此，他不会甘心。

The existing drug in view of sinus bradycardia has relatively low effect and many evident side effect if it is used long term.

因此，积极寻求安全有效的治疗手段来治疗窦性心动过缓，改善病人的生活质量，减少猝死的发生率，有其现实的经济意义和社会意义。