[名词解释] 铅线

漏斗胸 正常的Q波振幅应小于同导联中R波的多少（） ["1/2","1/3","1/4","1/5","1/6"] 皮下气肿 对于慢性肺源性心脏病心律失常的治疗不正确的是（） ["偶发房性期前收缩，以纠正缺氧为主","窦性心动过速不宜用β受体阻滞剂","频发室性期前收缩选用利多卡因","室性心动过速可用利多卡因","频发房性期前收缩选用常规剂量洋地黄"] 麻疹黏膜斑 铅线