{"ops":[{"attributes":{"color":"#f85a54"},"insert":"房室延搁和全心舒张期"},{"insert":"\n\n"},{"attributes":{"color":"#00aeec"},"insert":"房室延搁"},{"insert":"\n"},{"attributes":{"color":"#18191c"},"insert":"兴奋经过房室交界从心房传到心室时，传导速度减慢，耽搁了0.1秒"},{"insert":"\n\n"},{"attributes":{"color":"#18191c"},"insert":"为什么呢？"},{"insert":"\n"},{"attributes":{"color":"#18191c"},"insert":"心肌细胞分为两类"},{"insert":"\n"},{"attributes":{"color":"#18191c"},"insert":"快反应细胞：0期去极化是快钠通道介导的钠内流，比如心室肌细胞"},{"insert":"\n"},{"attributes":{"color":"#18191c"},"insert":"慢反应细胞：0期去极化是慢钙通道介导的钙内流，比如窦房结细胞"},{"insert":"\n"},{"attributes":{"color":"#18191c"},"insert":"而影响心肌细胞传导性最重要的因素是0期去极化速度与幅度"},{"insert":"\n"},{"attributes":{"color":"#18191c"},"insert":"因此快反应细胞传导也快，慢反应细胞传导也慢"},{"insert":"\n"},{"attributes":{"color":"#18191c"},"insert":"所以房室交界区之所以传导速度慢是因为有慢反应细胞—房室结细胞"},{"insert":"\n"},{"attributes":{"color":"#18191c"},"insert":"那么就可以用钙拮抗剂维拉帕米来改变房室交界区的传导"},{"insert":"\n\n"},{"attributes":{"class":"cut-off"},"insert":{"cut-off":{"type":"5","url":"https://b1.sanwen.net/b_article/02db465212d3c374a43c60fa2625cc1caeaab796.png"}}},{"insert":"\n1⃣️有房室延搁的出现说明心房和心室的活动不同步\n那么有没有房室同步的情况？\n有，三度房室传导阻滞自带房室分离的，间或可闻及大炮音\n\n2⃣️生理上的房室延搁在心电图上表现为PR间期0.12～0.20秒\n\n"},{"attributes":{"class":"normal-img"},"insert":{"native-image":{"alt":"read-normal-img","url":"https://b1.sanwen.net/b_article/9beb803fc1e71693b2a8849ef1c7581466050cc3.jpg","width":3024,"height":4032,"size":3352968,"status":"loaded"}}},{"insert":" \n🌷有没有PR间期<0.12秒的情况\n有，预激综合征（WPW）\n是因为其在房室结之外长了一个Kent束，它并不存在房室延搁 （结外生枝）\n\n🌷生理学上的房室延搁是室上速快慢双路径中的快路径\n所以一个房性早搏通过折返环中的慢路径下传，其后的P'R间期显著延长\n\n3⃣️房室延搁的这0.1秒就是心房收缩的0.1秒\n心动周期有0.8秒\n"},{"attributes":{"color":"#00aeec"},"insert":"全心舒张期"},{"insert":"0.4秒\n\n"},{"attributes":{"class":"normal-img"},"insert":{"native-image":{"alt":"read-normal-img","url":"https://b1.sanwen.net/b_article/6b9474da20818546a01e2388647ed248b141849b.jpg","width":3024,"height":4032,"size":3568497,"status":"loaded"}}},{"insert":"🌷 心率增快，舒张期缩短\n而舒张期时心室充盈、冠脉血流量增加\n所以\n心率增快时会导致只见收缩不见泵血、只见心跳没有脉搏，这就是房颤发作时的脉搏短促\n&一切快速心律失常都会发生心绞痛（冠脉没有病变，也会发生心绞痛，亮瞎！）\n\n"},{"attributes":{"class":"cut-off"},"insert":{"cut-off":{"type":"5","url":"https://b1.sanwen.net/b_article/02db465212d3c374a43c60fa2625cc1caeaab796.png"}}},{"insert":"\n"},{"attributes":{"color":"#f85a54"},"insert":"体循环平均充盈压"},{"insert":"：循环血量与血管容量的匹配情况\n血容量大—血压高，血容量小—血压低\n所以治疗高血压最无耻的方法就是利尿\n\n复习一下：\n动脉血压形成有四个因素：体循环平均充盈压、心脏收缩、大动脉管壁弹性、外周阻力\n动脉血压调节有五个因素：体循环平均充盈压、心室搏出量、心率、大动脉管壁弹性、外周阻力\n心率：只调节不参与\n\n"},{"attributes":{"class":"cut-off"},"insert":{"cut-off":{"type":"5","url":"https://b1.sanwen.net/b_article/02db465212d3c374a43c60fa2625cc1caeaab796.png"}}},{"insert":"\n"},{"attributes":{"color":"#f85a54"},"insert":"直捷通路"},{"insert":"\n休克有三个时期：1⃣️只出不进2⃣️只进不出3⃣️DIC\n只出不进是指血液进入微循环之后没有进迂回通路，而是进入直捷通路回流了\n\n真毛细血管是迂回通路的\n通血毛细血管是直捷通路的\n\n微循环有三条通路：\n1⃣️动静脉短路（3个部分）：微动脉—动静脉吻合支—微静脉\n2⃣️直捷通路（4个部分） ：微动脉—后微动脉—"},{"attributes":{"color":"#ffb027"},"insert":"通血毛细血管"},{"insert":"—微静脉\n3⃣️迂回通路（5个部分） ：微动脉—后微动脉—毛细血管前括约肌—"},{"attributes":{"color":"#ffb027"},"insert":"真毛细血管"},{"insert":"—微静脉\n\n\n\n\n\n\n"}]}
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