[名词解释] 活跃期

标准心电图中心前导联和肢体导联各为() ["A．3和9个","B．4和8个","C．5和7个","D．6和6个","E．2和10个"] 潜伏期 下列哪种药物过量，可使QRS时间延长() ["A．奎尼丁","B．硝酸甘油","C．消心痛","D．吗啡","E．普萘洛尔"] 生理性缩复环 心率缓慢并伴有心缩无力的患者，最好选用() ["A．阿托品","B．肾上腺素","C．多巴酚丁胺","D．去甲肾上腺素","E．多巴胺"] 活跃期