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心脏生理与心率失常

2017-09-20 40页 doc 138KB 17阅读

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心脏生理与心率失常心脏生理与心率失常 0102001心律失常cardiac arrhythmia心律紊乱;心律不齐;循环障碍;传导阻滞正常心律起源于窦房结,频率60次,100次/min(成人),比较规则。窦房结冲动经正常房室传导系统顺序激动心房和心室,传导时间恒定(成人0.12,1.21秒);冲动经束支及其分支以及浦肯野纤维到达心室肌的传导时间也恒定(,0.10秒)。心律失常(cardiac arrhythmia)指心律起源部位、心搏频率与节律以及冲动传导等任一项异常。“心律紊乱”或“心律不齐”等词的含义偏重于表示节律的失常,心律失常既包括节...
心脏生理与心率失常
心脏生理与心率失常 0102001心律失常cardiac arrhythmia心律紊乱;心律不齐;循环障碍;传导阻滞正常心律起源于窦房结,频率60次,100次/min(成人),比较规则。窦房结冲动经正常房室传导系统顺序激动心房和心室,传导时间恒定(成人0.12,1.21秒);冲动经束支及其分支以及浦肯野纤维到达心室肌的传导时间也恒定(,0.10秒)。心律失常(cardiac arrhythmia)指心律起源部位、心搏频率与节律以及冲动传导等任一项异常。“心律紊乱”或“心律不齐”等词的含义偏重于表示节律的失常,心律失常既包括节律又包括频率的异常,更为确切和恰当。增强心肌自律性;拟交感神经药;异丙肾上腺素等;迷走神经抑制药物;阿托品;碱化剂;克分子乳酸钠;碳酸氢钠;迷走神经兴奋剂;新斯的明;洋地黄制剂;甲氧明;苯福林;抗心律失常药物【诊断】【治疗措施】【病因学】【发病机理】【预后】【概述】


正常心律起源于窦房结,频率60次,100次/min(成人),比较规则。窦房结冲动经正常房室传导系统顺序激动心房和心室,传导时间恒定(成人0.12,1.21秒);冲动经束支及其分支以及浦肯野纤维到达心室肌的传导时间也恒定(,0.10秒)。心律失常(cardiac arrhythmia)指心律起源部位、心搏频率与节律以及冲动传导等任一项异常。“心律紊乱”或“心律不齐”等词的含义偏重于表示节律的失常,心律失常既包括节律又包括频率的异常,更为确切和恰当。


【诊断】


[心律失常的分类] 心律失常可按发生原理,心律失常时心率的快慢,以及心律失常时循环障碍严重程度和预后分类。 按发生原理,心律失常分为冲动发生异常、传导异常以及冲动发生与传导联合异常。这种分类

主要根据实验研究结果,在临床诊断技术目前尚难确定心律失常电生理机制的状况下,实用价值不高。此外,某些快速心律失常起始和持续的机制可能不同,如由异常自律性引起的室性早搏,可由折返机制而形成持续型室性心动过速。 按心律失常时心率的快慢,心律失常可分为快速性和缓慢性心律失常。近年来有些学者还提出按心律失常时循环障碍严重程度和预后,将心律失常分为致命性、潜在致命性和良性三类。这两种分类方法简易可行,结合临床实际,对心律失常的诊断和防治有一定帮助。 心律失常性质的确诊大多要靠心电图,但相当一部分病人可根据病史和体征作出初步诊断。详细追问发作时心率、节律(规则与否、漏搏感等),发作起止与持续时间。发作时有无低血压、昏厥或近乎昏厥、抽搐、心绞痛或心力衰竭等表现,以及既往发作的诱因、频率和治疗经过,有助于判断心律失常的性质。 for computer software engineering GB/T50314-2000 of electrical installations code for construction and acceptance of GBJ232- 92 intelligent building weak design construction figure set GJBT-471 2. system description this times engineering weak design including: hours a Kok information facilities system integrated wiring system (containing room network, communications part) wired TV system information guide and the released system hours II Kok public security system fire automatically alarm system (containing public broadcast part) security technology prevention system security monitoring system out entrance control system car library management system hours three Kok building equipment monitoring system hours four Kok information application system queued station ICU visitation system operation the system monitoring and training system call intercom system hours, five hours Kok Kok intelligent integrated system of information system (1) cabling systems (including computer room network, communication component) computer network systems and voice communications systems Center of information on medical floor computer room located in the engine room. Voice communication system using a local telecommunications operator providing voice service, configuration-independent integrated services digital program-controlled switchboards. Operators providing communications ... If any compatibility requirements, by way of increased access to the Communications Board within the chassis to meet 发作时体检应着重于判断心律失常的性质及心律失常对血流动力状态的影响。听诊心音了解心室搏动率的快、慢和规则与否,结合颈静脉搏动所反映的心房活动情况,有助于作出心律失常的初步鉴别诊断。心率缓慢(,60次/min)而规则的以窦性心动过缓、2?1或3?1或完全性房室传导阻滞、或窦房阻滞、房室交接处心律为多见。心率快速(,100次/min)而规则的常为窦性心动过速、室上性心动过速、心房扑动或房性心动过速伴2?1房室传导,或室性心动过速。窦性心动过速较少超过160次/min,心房扑动伴2?1房室传导时心室率常固定在150次/min左右。不规则的心律中以过早搏动为最常见,快而不规则者以心房颤动或扑动、房性心动过速伴不规则房室传导阻滞为多;慢而不规则者以心房颤动(洋地黄治疗后)、窦性心动过缓伴窦性心律不齐、窦性心律合并不规则窦房或房室传导阻滞为多见。心律规则而第一心音强弱不等(大炮音),尤其是伴颈静脉搏动间断不规则增强(大炮波)的,提示房室分离,多见于完全性房室传导阻滞或室性心动过速。 颈动脉窦按摩对快速性心律失常的影响有助于鉴别诊断心律失常的性质。为避免发生低血压、心脏停搏等意外,应使患者在平卧位有心电图监测下进行,老年人慎用,有脑血管病变者禁用。每次按摩一侧颈动脉窦,一次按摩持续时间不超过5秒,可使心房扑动的室率成倍下降,还可使室上性心动过速立即转为窦性心律。 心律失常发作时的心电图记录是确诊心律失常的重要依据。应包括较长的?或V导联记录。注意P和QRS波形态、P-QRS关系、PP、PR与RR间期,判断基本1 心律是窦性还是异位。房室独立活动时,找出P波与QRS波群的起源(选择?、aVF、aVR、V和V、V导联)。P波不明显时,可试加大电压或加快纸速,作P156 波较明显的导联的长记录。必要时还可以用食管导联或右房内电图显示P波。经上述方法有意识地在QRS、ST和T波中寻找但仍未见P波时,考虑有心房颤动、扑动,房室交接处心律或心房停顿等可能。通过逐个提早或延迟心搏的性质和来源,最后判断心律失常的性质。 发作间歇期体检应着重于有无高血压、冠心病、瓣膜病、心肌病、心肌炎等器质性心脏病的证据。常规心电图、超声心动图、心电图运动负荷试验、放射性核素显影、心血管造影等无创和有创性检查有助于确诊或排除器质性心脏病。 动态心电图通过24小时连续心电图记录可能记录到心律失常的发作,自主神经系统对自发心律失常的影响,自觉症状与心律失常的关系,并评估治疗效果。然而难以记录到不经常发作的心律失常。 有创性电生理检查除能确诊缓慢性心律失常和快速心律失常的性质外,还能在心律失常发作间歇应用程序电刺激方法判断窦房结和房室传导系统功能,诱发室上性和室性快速心律失常,确定心律失常起源部位,评价药物与非药物治疗效果,以及为手术、起搏或消融治疗提供必要的信息。 信号平均心电图(signal averaged ECG)又称高分辨体表心电图(high resolution body surface ECG),可能在体表记录到标志心室肌传导延缓所致局部心肌延迟除极的心室晚电位。心室晚电位的存在为折返形成提供了有利基for computer software engineering GB/T50314-2000 of electrical installations code for construction and acceptance of GBJ232- 92 intelligent building weak design construction figure set GJBT-471 2. system description this times engineering weak design including: hours a Kok information facilities system integrated wiring system (containing room network, communications part) wired TV system information guide and the released system hours II Kok public security system fire automatically alarm system (containing public broadcast part) security technology prevention system security monitoring system out entrance control system car library management system hours three Kok building equipment monitoring system hours four Kok information application system queued station ICU visitation system operation the system monitoring and training system call intercom system hours, five hours Kok Kok intelligent integrated system of information system (1) cabling systems (including computer room network, communication component) computer network systems and voice communications systems Center of information on medical floor computer room located in the engine room. Voice communication system using a local telecommunications operator providing voice service, configuration-independent integrated services digital program-controlled switchboards. Operators providing communications ... If any compatibility requirements, by way of increased access to the Communications Board within the chassis to meet 础,因而记录到心室晚电位的病人,其室性心动过速、心室颤动和猝死发生的危险性相应增高。 运动试验可能在心律失常发作间歇时诱发心律失常,因而有助于间歇发作心律失常的诊断。抗心律失常药物(尤其是致心室内传导减慢的药物)治疗后出现运动试验诱发的室性心动过速,可能是药物致心律失常作用的表现。 【治疗措施】 心律失常的治疗应包括发作时治疗与预防发作。除病因治疗外,尚可分为药物治疗和非药物治疗两方面。 病因治疗包括纠正心脏病理改变、调整异常病理生理功能(如冠脉动态狭窄、泵功能不全、自主神经张力改变等),以及去除导致心律失常发作的其它诱因(如电解质失调、药物不良副作用等)。 药物治疗缓慢心律失常一般选用增强心肌自律性和(或)加速传导的药物,如拟交感神经药(异丙肾上腺素等)、迷走神经抑制药物(阿托品)或碱化剂(克分子乳酸钠或碳酸氢钠)。治疗快速心律失常则选用减慢传导和延长不应期的药物,如迷走神经兴奋剂(新斯的明、洋地黄制剂)、拟交感神经药间接兴奋迷走神经(甲氧明、苯福林)或抗心律失常药物。 目前临床应用的抗心律失常药物已有50种以上,常按药物对心肌细胞动作电位的作用来分类(Vaugham Williams法)(表3)。?类药抑制0相除极,曾被称为膜抑制剂,按抑制程度强弱及对不应期和传导速度的不同影响,再分为?a、?b和?c亚类,分别以奎尼丁、利多卡因和恩卡尼作为代表性药物。?类为肾上腺素能β受体阻滞剂;?类延长动作电位时限和不应期,以胺碘酮为代表性药物;?类为钙内流阻滞剂,以维拉帕米为代表性药物。近年又Sicilian Gambie 分类法。抗心律失常药物治疗不破坏致心律失常的病理组织,仅使病变区内心肌细胞电生理性能如传导速度和(或)不应期长短有所改变,长期服用均有不同程度的不良副作用,严重的可引起室性心律失常或心脏传导阻滞而致命。因而临床应用时宜严格掌握适应证,并熟悉几种常用抗心律失常药物的作用,包括半衰期、吸收、分解、排泄、活性代谢产物、剂量和副作用(表4,5)。 表3 抗心律失常药物的分类 电生理效应 亚类别 代表制剂 新制剂 传导速不应Ap时类 度 期 限 ?(钠通道阻滞? ? ? 大多奎尼丁、普鲁卡阿义马林a 剂) ? 因胺丙吡胺 (ajmaline) 吡美诺for computer software engineering GB/T50314-2000 of electrical installations code for construction and acceptance of GBJ232- 92 intelligent building weak design construction figure set GJBT-471 2. system description this times engineering weak design including: hours a Kok information facilities system integrated wiring system (containing room network, communications part) wired TV system information guide and the released system hours II Kok public security system fire automatically alarm system (containing public broadcast part) security technology prevention system security monitoring system out entrance control system car library management system hours three Kok building equipment monitoring system hours four Kok information application system queued station ICU visitation system operation the system monitoring and training system call intercom system hours, five hours Kok Kok intelligent integrated system of information system (1) cabling systems (including computer room network, communication component) computer network systems and voice communications systems Center of information on medical floor computer room located in the engine room. Voice communication system using a local telecommunications operator providing voice service, configuration-independent integrated services digital program-controlled switchboards. Operators providing communications ... If any compatibility requirements, by way of increased access to the Communications Board within the chassis to meet (pirmenol) 安搏律定 (aprindine) ? ?或? ? ? 利多卡因 美西律b 苯妥英 (mexiletine) 妥卡尼 (tocainide) ? ? ? = 恩卡尼 c (encainide) 氟卡尼 (flecainide) 劳卡尼 (lorcainide) 普罗帕酮 (propafenone) 乙吗噻嗪 (ethmozin) ?(β受体阻 ? = ? 普萘洛尔 其他β阻滞剂 滞剂) ?(动作电位时索他洛尔 ? =? ? 胺碘酮 限延长) (sotabl) ?钙内流阻滞苄普地尔 ? ? 维拉帕米 剂 (bepridil) 地尔硫卓 表4 常用的抗快速心律失常药用法 适应证 剂量和用法 类室 室 药名 主要不良反应 型 上 治疗量 维持量 性 性 口服0.2,口服0.2,0.4g,每低血压、抑制心0.3g,3,42h1次,共5次/d,肌收缩、室内传奎尼丁 次/d,长效++ ++ 复律 导阻滞、严重室quinidine 制剂0.3g,口服0.2g,3,4次性心律失常、胃每8,12h1/d,治疗过早搏动 肠道反应 ? a次 静注每5min100mg,低血压、心室内口服0.25,普鲁卡因胺 共1.0,1.2g,静滴传导阻滞、室性++ ++ 0.5g,每4,procainamide 0.5%每min5,10mg,心律失常、长期6h1次 共1,2g 服用发生红斑狼for computer software engineering GB/T50314-2000 of electrical installations code for construction and acceptance of GBJ232- 92 intelligent building weak design construction figure set GJBT-471 2. system description this times engineering weak design including: hours a Kok information facilities system integrated wiring system (containing room network, communications part) wired TV system information guide and the released system hours II Kok public security system fire automatically alarm system (containing public broadcast part) security technology prevention system security monitoring system out entrance control system car library management system hours three Kok building equipment monitoring system hours four Kok information application system queued station ICU visitation system operation the system monitoring and training system call intercom system hours, five hours Kok Kok intelligent integrated system of information system (1) cabling systems (including computer room network, communication component) computer network systems and voice communications systems Center of information on medical floor computer room located in the engine room. Voice communication system using a local telecommunications operator providing voice service, configuration-independent integrated services digital program-controlled switchboards. Operators providing communications ... If any compatibility requirements, by way of increased access to the Communications Board within the chassis to meet 口服0.5,1.0g,5次疮样或类风湿样 /d 表现 N-乙酰普鲁卡口服500,因胺 口服500,2500mg,同上,不引起红++ ++ 1000mg,每N-acetylpro- 每6h1次 斑狼疮样等表现 6h1次 cainemide 静注开始5,15min抑制心脏传导和内100mg,随后静滴口服100,丙吡胺 心肌收缩、胃肠++ ++ 每h20,30mg 200mg,每disopyramide 道反应、口干、口服100,200mg,46,8h1次 尿潴留 次/d 静注一次100, 安他唑啉 200mg 口服0.1,嗜睡、恶心、呕++ ++ antazoline 口服0.1,0.2g,4次0.2g,4次/d 吐 /d 静脉滴注咽干、头痛、眩静脉给药2.5mg/kg,0.25mg/min 晕、失眠、尿潴吡美诺 在1h内注完 ++ ++ 口服100,留、便秘、严重pirmenol 口服100,200mg,每200mg,每2快速异位心律失d2次 次/d 常 恶心、呕吐、皮静注一次1.5mg/kg 口服常咯啉 肤变色、肝肾功++ ++ 口服0.2,0.3g,3,0.2g,2,3pyrozoline 能损害、白细胞4次/d 次/d 减少 嗜睡、呕吐、肝静注50mg(5,10min阿义马林 口服50mg,3功能障碍、粒细++ ++ 注完) ajmaline 次/d 胞减少、静脉给口服100mg,3次/d 药可有灼热感 窦性停顿、房室静注50,100mg,每传导阻滞、抑制利多卡因 5,10min50mg,共静滴每/ ++ 心肌收缩、嗜睡、lidocaine 250,300mg min1,3mg 言语吞咽障碍、肌注250,300mg 四肢抽动 头晕、嗜睡、粒 ? 细胞减少,静脉b静注100mg(5min注口服或静注给药有局部刺苯妥英 完),然后每5,+ ++ 0.1g,3,4激、低血压、呼phenytoin 10min100mg,共次/d 吸抑制、窦性停300,1000mg 顿、室性心律失 常 美西律 / ++ 静注100,200mg或静滴每心动过缓、低血 for computer software engineering GB/T50314-2000 of electrical installations code for construction and acceptance of GBJ232- 92 intelligent building weak design construction figure set GJBT-471 2. system description this times engineering weak design including: hours a Kok information facilities system integrated wiring system (containing room network, communications part) wired TV system information guide and the released system hours II Kok public security system fire automatically alarm system (containing public broadcast part) security technology prevention system security monitoring system out entrance control system car library management system hours three Kok building equipment monitoring system hours four Kok information application system queued station ICU visitation system operation the system monitoring and training system call intercom system hours, five hours Kok Kok intelligent integrated system of information system (1) cabling systems (including computer room network, communication component) computer network systems and voice communications systems Center of information on medical floor computer room located in the engine room. Voice communication system using a local telecommunications operator providing voice service, configuration-independent integrated services digital program-controlled switchboards. Operators providing communications ... If any compatibility requirements, by way of increased access to the Communications Board within the chassis to meet mexiletine 静滴250,500mg min1,2mg 压、头晕、恶心、 口服200,口服200,呕吐 300mg,3,4次/d 300mg,3,4 次/d 静滴每min30,口服400,妥卡尼 45mg,共15min 眩晕、复视、胃/ ++ 600mg,3次tocainide 口服400,600mg,3肠道反应 /d 次/d 口服100,卡马西平 口服100,眩晕、嗜睡、消+ ++ 200mg,3次carbamazepine 200mg,3,4次/d 化不良 /d 静滴200mg(每头晕、手或指震 min2mg),30min后口服25,颤、共济失调、安搏律定 + ++ 100mg,6h后100mg 50mg,2,3胃肠道反应、粒aprindine 口服50,75mg,每次/d 细胞减少、抑制 6h1次 心肌收缩 静注1,2mg/kg, 15min以上注完 口服头晕、胃肠道反恩卡尼 ++ ++ 口服25mg,3,4次25mg,3,4应、皮疹等,严encainide /d,可逐渐增至次/d 重心律失常 50mg,3,4次/d 静注1,2mg/kg, 头晕、头痛、恶10min以上注完 口服50,氟卡尼 心、乏力、神经++ ++ 口服50,100mg,2次100mg,2次flecainide 过敏、感觉异常,/d,可逐渐增至/d 严重心律失常 200mg,2次/d 静滴每min2mg,或以失眠、多梦、焦 100mg1h滴完 口服虑、头晕、头痛、劳卡尼 ++ ++ 口服100mg,2次/d,100mg,2次恶心、呕吐、感? clorcainide 可逐渐增至200mg,2/d 觉异常,严重心 次/d 律失常 静注70mg/次,3,恶心、呕吐、头普罗帕酮 5min内注完 口服300,痛、晕眩、立位++ ++ propafenone 口服150mg,3,4次600mg/d 低血压、房室与 /d 室内传导阻滞 静注1.8mg/kg, 恶心、呕吐、头乙吗噻嗪 10min以内注完 口服100mg,++ ++ 痛、眩晕、共济ethmozin 口服150,300mg,33次/d 失调、低血压 次/d 西苯唑啉 静注1,2mg/kg 口服30,恶心、呕吐、腹+ + cibenzoline 口服30,80mg,3,480mg,3次泻、口干、头晕、 for computer software engineering GB/T50314-2000 of electrical installations code for construction and acceptance of GBJ232- 92 intelligent building weak design construction figure set GJBT-471 2. system description this times engineering weak design including: hours a Kok information facilities system integrated wiring system (containing room network, communications part) wired TV system information guide and the released system hours II Kok public security system fire automatically alarm system (containing public broadcast part) security technology prevention system security monitoring system out entrance control system car library management system hours three Kok building equipment monitoring system hours four Kok information application system queued station ICU visitation system operation the system monitoring and training system call intercom system hours, five hours Kok Kok intelligent integrated system of information system (1) cabling systems (including computer room network, communication component) computer network systems and voice communications systems Center of information on medical floor computer room located in the engine room. Voice communication system using a local telecommunications operator providing voice service, configuration-independent integrated services digital program-controlled switchboards. Operators providing communications ... If any compatibility requirements, by way of increased access to the Communications Board within the chassis to meet 次/d,或120,/d, 乏力、嗜睡、肝 160mg,2次/d 功能损害,心律 失常、心功能抑 制 静注0.5,1mg(5,普萘洛尔 口服10,++ + 10min注完) propranolol 20mg,3次/d 口服20mg,3,4次/d 吲哚洛尔 静注0.2,1mg 口服5,++ + pindolol 口服5,10mg,3次/d 10mg,3次/d 阿替洛尔 口服25,50mg,1,2口服25,++ + atenolol 次/d 50mg,1次/d 美托洛尔 口服25,50mg,2,3口服25mg,2++ + 心动过缓、低血metoprolol 次/d 次/d ? 压、心力衰竭、倍他洛尔 口服10,20mg,1次口服10,哮喘等 ++ + betaxolol /d 20mg,1次/d 口服醋丁洛尔 静注10,20mg ++ + 100mg,3次acebutolol 口服100mg,3次/d /d 艾司洛尔 静滴每min25,++ + / exmolol 300µg/kg 氟司洛尔 静滴每min0.5,++ + / flestolol 10µg/kg 静注250mg,每6,口服血压波动、恶心、溴苄铵 8h1次 / + 0.1g,3,4呕吐、体位性低bretylium 口服0.1,0.4g,3,次/d 血压 4次/d 心动过缓、皮肤 静注250,500mg 口服变色、角膜微沉胺碘酮 ++ ++ 口服200mg,3,4次200mg,1,2淀、甲状腺功能amiodarone /d 次/d 失调、严重心律 失常、肺纤维化 ? 类似普萘洛尔的静注20,60mg/次,不良反应,偶有索他洛尔 10min以上注完 口服开始++ ++ 神经系统反应和sotalol 口服开始80,80mg,2次/d 严重室性心律失160mg,2次/d 常 口服开始5,10mg,2 口服最大与溴苄铵的不良倍他尼定 / + 次/d,以后增至10,维持量反应同,主要为bethanidine 30mg,3次/d 200mg/d 体位性低血压 ? 维拉帕米 ++ + 静注5,10mg(5,口服房室传导阻滞、 for computer software engineering GB/T50314-2000 of electrical installations code for construction and acceptance of GBJ232- 92 intelligent building weak design construction figure set GJBT-471 2. system description this times engineering weak design including: hours a Kok information facilities system integrated wiring system (containing room network, communications part) wired TV system information guide and the released system hours II Kok public security system fire automatically alarm system (containing public broadcast part) security technology prevention system security monitoring system out entrance control system car library management system hours three Kok building equipment monitoring system hours four Kok information application system queued station ICU visitation system operation the system monitoring and training system call intercom system hours, five hours Kok Kok intelligent integrated system of information system (1) cabling systems (including computer room network, communication component) computer network systems and voice communications systems Center of information on medical floor computer room located in the engine room. Voice communication system using a local telecommunications operator providing voice service, configuration-independent integrated services digital program-controlled switchboards. Operators providing communications ... If any compatibility requirements, by way of increased access to the Communications Board within the chassis to meet verapamil 10min注完)。 80mg,3,4心动过缓、低血 口服80mg,3,4次/d 次 /d 压、心力衰竭 静注3,4mg/kg1次 口服300,类似维拉帕米的苄普地尔 ++ + 口服300,800mg,1800mg,1次不良反应,可致bepridil 次/d /d 室性心律失常 静注每次75,类似维拉帕米的地尔硫卓 150µg/kg 口服60mg,3++ / 不良反应,可致diltiazem 口服60,90mg,3次次/d 皮疹 /d 心可定 口服15,60mg,3次口服15,心动过缓、低血/ + segontin /d 30mg,3次/d 压 静注静注0.6,0.8mg,2h毛花甙C ++ + 0.4mg,1次后再注0.2,0.4mg /d 静注0.25, 0.5mg,4,6h后再注口服0.2, 地高辛 ++ + 0.25mg 0.5mg,1次室性心律失常、 口服0.25,/d 房性或房室交接 0.75mg,3次/d,共2d ? 处性心动过速、 房室传导阻滞、口服0.2,0.3mg,然口服0.05, 胃肠道反应 洋地黄素甙 ++ + 后每6h0.1mg,1d内0.1mg,1次 0.5,0.7mg /d 口服0.1,口服0.1,0.2g(精0.2g(精制新福甙 ++ + 制品0.5,1mg),1次品0.5,/d 1mg),1次/d 腹痛、恶心、肌肌注0.5,1.0mg 新斯的明 + / / 肉抽搐、心动过静注5,10mg 缓 腾喜龙依酚氯+ / 静注5,10mg / 胺 肌注0.5,1.0mg使其 苯肾上腺素 ++ / 收缩期血压升高到/ 21.3kPa(160mmHg) 他 静注5,10mg,使收心室内传导阻缩期血压升高到甲氧明 ++ / / 滞、心房停顿、21.3kPa(160mmHg),胃肠道反应 停止注射 静滴0.3,0.5%,每口服1g,3,心室内传导阻氯化钾 + + h1g,共1,2g。口服4次/d 滞、心房停顿、 for computer software engineering GB/T50314-2000 of electrical installations code for construction and acceptance of GBJ232- 92 intelligent building weak design construction figure set GJBT-471 2. system description this times engineering weak design including: hours a Kok information facilities system integrated wiring system (containing room network, communications part) wired TV system information guide and the released system hours II Kok public security system fire automatically alarm system (containing public broadcast part) security technology prevention system security monitoring system out entrance control system car library management system hours three Kok building equipment monitoring system hours four Kok information application system queued station ICU visitation system operation the system monitoring and training system call intercom system hours, five hours Kok Kok intelligent integrated system of information system (1) cabling systems (including computer room network, communication component) computer network systems and voice communications systems Center of information on medical floor computer room located in the engine room. Voice communication system using a local telecommunications operator providing voice service, configuration-independent integrated services digital program-controlled switchboards. Operators providing communications ... If any compatibility requirements, by way of increased access to the Communications Board within the chassis to meet 1,2g,3,4次/d 胃肠道反应 静注1,3g(将血压下降、呼吸 10%20ml针剂稀释一心搏停顿、心动 倍),10min以上注过缓、房室和室硫酸镁 + + / 完,继而静滴,缺镁内传导阻滞、乏 者第一日6,9g,第力、瘫痪、嗜睡、 二日2,3g 昏迷 5,10mg或15,20mg 生理盐水20ml稀释,房室传导阻滞、 三磷酸腺甙 + / 在5s内推注完毕,无/ 心脏停搏、室性 效者3,5min后可重心动过速 复 静注60mg。肌注20,口服1.5,恶心、反酸、中苦参 + + 40mg,口服1.5,3.0g,3次d 上腹痛 3.0g,3次d 表5 常用的抗缓慢心律失常药用法 剂量和用法 药 名 适应证 主要不良反应 治疗量 维持量 静滴1,3µg/min(1,头痛、眩晕、震高度或完全2mg置入5%葡萄糖液颤、皮肤潮红、异丙肾上腺房室传导阻500ml中滴注每分同左 恶心,心绞痛加素 滞、病窦、1ml) 重,快速心律失心脏骤停 舌下含每3,4h10,常 15mg 神经过敏、眩高度或完全肌肉或皮下注射1次口服25mg,3次晕、失眠、快速床黄碱 性房室传导15,30mg /d 心律失常、高血阻滞 口服25mg,3次/d 压 高度或完全0.1%0.3,0.6ml静神经过敏、面色 性房室传导脉、肌肉、皮下或心静滴1,苍白、震颤、高肾上腺素 阻滞、心脏腔注射,静滴1,4µg/min 血压、快速心律 骤停 4µg/min 失常 阿托品1mg皮下、肌口服0.3, 肉或静脉注射,口服0.6mg,3次/d 口干、眩晕、皮0.3,0.6mg,3次/d 肤潮红、尿潴病窦、房室山莨菪碱静注10,口服5,阿托品类 留、青光眼加传导阻滞 20mg/次,口服5,10mg,3次/d 重、快速心律失10mg,3次/d 常 口服15,普鲁苯辛口服15, 30mg,3次/d 30mg,3次/d for computer software engineering GB/T50314-2000 of electrical installations code for construction and acceptance of GBJ232- 92 intelligent building weak design construction figure set GJBT-471 2. system description this times engineering weak design including: hours a Kok information facilities system integrated wiring system (containing room network, communications part) wired TV system information guide and the released system hours II Kok public security system fire automatically alarm system (containing public broadcast part) security technology prevention system security monitoring system out entrance control system car library management system hours three Kok building equipment monitoring system hours four Kok information application system queued station ICU visitation system operation the system monitoring and training system call intercom system hours, five hours Kok Kok intelligent integrated system of information system (1) cabling systems (including computer room network, communication component) computer network systems and voice communications systems Center of information on medical floor computer room located in the engine room. Voice communication system using a local telecommunications operator providing voice service, configuration-independent integrated services digital program-controlled switchboards. Operators providing communications ... If any compatibility requirements, by way of increased access to the Communications Board within the chassis to meet 窦性心动过甲状腺素片口服缓或结性心甲状腺机能亢0.1,0.2mg/d 甲状腺激素 律,尤其是同左 进的表现,快速三碘甲状腺原氨酸钠甲状腺功能心律失常 片10,20ng/d 低下所致者 肾上腺皮质 静滴氢化可的松机能亢进的表房室传导阻肾上腺皮质200,600mg(24h内) 口服强的松现,钠潴留,糖滞尤其是炎激素 口服强的松10mg4次10mg,4次/d 尿病恶化,炎症症所致 /d 播散,青光眼, 精神病 酸中毒或高静滴快速滴入25,诱发心力衰竭、血钾引起的克分子乳酸50ml,继续而5,碱中毒、低血房室传导阻 钠 7ml/kg,在数h内滴钾、快速心律失滞,心脏骤完 常 停 静滴400,恶心、呕吐、上烟酰胺 病窦 800mg/d(个别可增至口服2500mg/d 腹部灼热感、皮 2000mg),2,4周 肤潮红、瘙痒 非药物治疗包括机械方法兴奋迷走神经,心脏起搏器,电复律,电除颤,电消融,射频消融和冷冻或激光消融以及手术治疗。反射性兴奋迷走神经的方法有压迫眼球、按摩颈动脉窦、捏鼻用力呼气和摒住气等。心脏起搏器多用于治疗缓慢心律失常,以低能量电流按预定频率有规律地刺激心房或心室,维持心脏活动;亦用于治疗折返性快速心律失常和心室颤动,通过程序控制的单个或连续快速电刺激中止折返形成。直流电复律和电除颤分别用于终止异位性快速心律失常发作和心室颤动,用高压直流电短暂经胸壁作用或直接作用于心脏,使正常和异常起搏点同时除极,恢复窦房结的最高起搏点。为了保证安全,利用患者心电图上的R波触发放电,避免易惹期除极发生心室颤动的可能,称为同步直流电复律,适用于心房扑动、心房颤动、室性和室上性心动过速的转复。治疗心室扑动和心室颤动时则用非同步直流电除颤。电除颤和电复律疗效迅速、可靠而安全,是快速终止上述快速心律失常的主要治疗方法,但并无预防发作的作用。 晚近对严重而顽固的异位性快速心律失常,如反复发作的持续室性心动过速伴显著循环障碍、心源性猝死复苏存活者或预激综合征合并心室率极快的室上性快速心律失常患者,主张经临床电生理测试程序刺激诱发心律失常后,静脉内或口服抗心律失常药,根据药物抑制诱发心律失常的作用,判断其疗效而制定治疗方案。药物治疗无效者,结合临床电生理对心律失常折返途径的定位,考虑经静脉导管电灼、射频、冷冻、激光或选择性酒精注入折返径路所在区心肌的冠脉供血分支或手术等切断折返途径的治疗。 【病因学】 for computer software engineering GB/T50314-2000 of electrical installations code for construction and acceptance of GBJ232- 92 intelligent building weak design construction figure set GJBT-471 2. system description this times engineering weak design including: hours a Kok information facilities system integrated wiring system (containing room network, communications part) wired TV system information guide and the released system hours II Kok public security system fire automatically alarm system (containing public broadcast part) security technology prevention system security monitoring system out entrance control system car library management system hours three Kok building equipment monitoring system hours four Kok information application system queued station ICU visitation system operation the system monitoring and training system call intercom system hours, five hours Kok Kok intelligent integrated system of information system (1) cabling systems (including computer room network, communication component) computer network systems and voice communications systems Center of information on medical floor computer room located in the engine room. Voice communication system using a local telecommunications operator providing voice service, configuration-independent integrated services digital program-controlled switchboards. Operators providing communications ... If any compatibility requirements, by way of increased access to the Communications Board within the chassis to meet 心律失常可见于各种器质性心脏病,其中以冠状动脉粥样硬化性心脏病(简称冠心病)、心肌病、心肌炎和风湿性心脏病(简称风心病)为多见,尤其在发生心力衰竭或急性心肌梗塞时。发生在基本健康者或植物神经功能失调患者中的心律失常也不少见。其它病因尚有电解质或内分泌失调、麻醉、低温、胸腔或心脏手术、药物作用和中枢神经系统疾病等。部分病因不明。 【发病机理】 [与心律失常有关的心脏解剖和生理] (一)心脏起搏传导系统 心肌大部分由普通心肌纤维组成,小部分为特殊分化的心肌纤维,后者组成心脏的起搏传导系统。 心脏的起搏传导系统包括窦房结、结间束、房室结、房室束(希司束)、左右束支及其分支以及浦顷野纤维网。窦房结位于右心房上腔静脉入口处,是控制心脏正常活动的起搏点。房室结位于房间隔底部、卵圆窝下、三尖瓣内瓣叶与冠状窦开口之间,向前延续成房室束。房室束又称希司束,近端为主干或穿入部分,穿过中心纤维体,沿室间隔膜向前直至隔的肌顶部分(分支部分)。先分出左束支后分支,再分出左束支前分支,本身延续成右束支,构成三支系统。穿入部分经过中心纤维体时,位于二尖瓣与三尖瓣环之间,分支部分则至室间隔膜部、肌肉部和主动脉瓣邻近。左束支后分支粗短、较早呈扇形分支;左束支前分支和右束支细长,分支晚,两侧束支于心内膜下走向心尖分支再分支,细支相互吻合成网,称为浦肯野纤维网,深入心室肌(图1)。 图1 房室传导系统解剖示意 窦房结与房室结间有边界不清的前、中、后三条结间束连接。结间束终末连接房室结的部分,与房室结、房室束主干合称房室交接处(亦称房室交界或房室连接处)。 for computer software engineering GB/T50314-2000 of electrical installations code for construction and acceptance of GBJ232- 92 intelligent building weak design construction figure set GJBT-471 2. system description this times engineering weak design including: hours a Kok information facilities system integrated wiring system (containing room network, communications part) wired TV system information guide and the released system hours II Kok public security system fire automatically alarm system (containing public broadcast part) security technology prevention system security monitoring system out entrance control system car library management system hours three Kok building equipment monitoring system hours four Kok information application system queued station ICU visitation system operation the system monitoring and training system call intercom system hours, five hours Kok Kok intelligent integrated system of information system (1) cabling systems (including computer room network, communication component) computer network systems and voice communications systems Center of information on medical floor computer room located in the engine room. Voice communication system using a local telecommunications operator providing voice service, configuration-independent integrated services digital program-controlled switchboards. Operators providing communications ... If any compatibility requirements, by way of increased access to the Communications Board within the chassis to meet 心房肌与心室肌之间有纤维环,心房兴奋不能经心肌传至心室,房室结与房室束为正常房室间传导的唯一通路。 心脏传导系统的血供:窦房结、房室结和房室束主干大多由右冠状动脉供血,房室速 分支部分、左束支前分支和右束支血供来自左冠状动脉前降支,而左束支后分支则由左冠状动脉回旋支和右冠状动脉供血。 窦房结和房室结有丰富的副交感神经分布。前者来自右侧迷走神经、后者来自左侧迷走神经。 (二)心肌的电生理特性 心肌细胞有自律性、兴奋性、传导性和收缩性,前三者和心律失常关系密切。 1. 自律性 部分心肌细胞能有规律地反复自动除极(由极化状态转为除极化状态),导致整个心脏的电-机械活动,这种性能称为自律性,具有这种性能的心肌细胞称为自律细胞。窦房结、结间束、房室交接处、束支和浦顷野纤维网均有自律性;腔静脉和肺静脉的入口、冠状窦邻近的心肌以及房间隔和二尖瓣环也具有自律性,而心房肌、房室结的房-结区和结区以及心室肌则无自律性。 自律性的产生原理复杂,现认为是自律细胞舒张期胞膜有钠离子和(或)钙离子内流、钾离子外流,钠和(或)钙离子内流超过钾离子外流时,膜内负电位渐减,达到阈电位,产生自动除极,形成动作电位。 心肌细胞的自律性受下列因素影响:?最大舒张期膜电位;?阈电位;?自动除极的坡度。当最大舒张期膜电位减小、除极坡度变陡、阈电位接近静止膜电位时,自律性增高;反之,自律性低下。三者中以除极坡度影响最大(图2)。正常心脏以窦房结的自律性最高,其它具有自律性的心肌舒张期自动除极未达到阈电位前,已被窦房结下传的冲动所激动,分别被称为最高起搏点和潜在起搏点。 图2 影响自律性的因素 上:位相4除极坡度由a?b,自律性减低 下:阈电位自1转为2(少负),自律性降低最大舒张期电位自1转为2(少负),自律性降低最大舒张期电位自1转为2(更负),同时阈电位自1转为2(少负)自律性更低 2.兴奋性(即应激性) 心肌细胞受内部或外来适当强度刺激时,能进行除极和复极,产生动作电位,这种性能称为兴奋性或应激性。不足以引起动作电位的刺for computer software engineering GB/T50314-2000 of electrical installations code for construction and acceptance of GBJ232- 92 intelligent building weak design construction figure set GJBT-471 2. system description this times engineering weak design including: hours a Kok information facilities system integrated wiring system (containing room network, communications part) wired TV system information guide and the released system hours II Kok public security system fire automatically alarm system (containing public broadcast part) security technology prevention system security monitoring system out entrance control system car library management system hours three Kok building equipment monitoring system hours four Kok information application system queued station ICU visitation system operation the system monitoring and training system call intercom system hours, five hours Kok Kok intelligent integrated system of information system (1) cabling systems (including computer room network, communication component) computer network systems and voice communications systems Center of information on medical floor computer room located in the engine room. Voice communication system using a local telecommunications operator providing voice service, configuration-independent integrated services digital program-controlled switchboards. Operators providing communications ... If any compatibility requirements, by way of increased access to the Communications Board within the chassis to meet 激称为阈值下刺激,能引起动作电位的最低强度的刺激称为阈值下刺激,能引起动作电位提了低强度的刺激称为阈值刺激。心肌细胞的兴奋性高低以阈值刺激强度衡量,刺激必须强于阈值才能引起动作电位的提示心肌细胞兴奋性低下,弱于阈值的刺激即能引起动作电位的提示心肌细胞兴奋性增高。 动作电位及其产生原理:心肌细胞静止时细胞膜内呈负电位,相对稳定。这是由于细胞内钾离子浓度高于细胞外20,30倍,钾离子外流,带出阳电荷,而同时不易通过细胞膜的分子较大的阴离子则留在细胞内,阻止带阳电荷的钾离子外移之故。阈值刺激促使心肌细胞兴奋,产生动作电位。首先细胞膜上的快钠通道开放,由于细胞外钠离子浓度高于细胞内10,20倍,膜内电位又负于膜外,钠离子快速大量涌入细胞内,使膜内负电位迅速转为+30,+40mV,形成动作电位的位相0(除极)。随后,钠通道部分关闭,钠离子快速内流中止,钾离子外流,膜电位开始下降(位相1,起始快速复极)。继而钙离子和钠离子缓慢内流及钾离子缓慢外流,膜电位改变少(位相2,缓慢复极)。随后钾离子外流加速,膜电位快速下降至静止膜电位水平(位相3,终末快速复极),而舒张期静止膜电位即称为位相4。自律细胞位相4钠离子内流(浦顷野细胞)和(或)钾离子外流衰减(窦房结细胞),使膜电位渐减,达到阈电位时即形成自动除极。非自律细胞的位相4膜电位恒定(图3)。自位相0起始至位相3结束所需时限称为动作电位时限。近年随着心肌细胞电生理研究的深入,电压钳和斑片钳技术的应用,对心肌细胞膜的离子通道及其离子流情况又提出了一些新概念。 图3 左:心肌细胞的动作电位和不应期 右:膜反应曲线a、b、c示细胞复极过程中对刺激的反应 a-不能传布的局部反应 b-第一个能传布的反应 c-第一个正常反应 窦房结和房室结的动作电位曲线与其它部位不同,具有以下特点:位相0除极缓慢、振幅低,位相1、2不见,位相4除极坡度陡,静止膜电位和阈电位均低(静止膜电位-40,-70mV,阈电位-30,-40mV,而心室肌等则分别为-90mV与-60mV),动作电位时限短(图4)。近年来已证实这两处的位相0除极是钙离子和钠离子缓慢内流所形成,因而被称为慢反应细胞。其它部位心肌细胞除极由钠离子快速内流形成,因而又称快反应细胞。两种细胞的电生理特性有显著不同:慢反应细胞自律性较高、传导性能差,易发生传导障碍;而快反应细胞则传导性能可靠。 图4 左:窦房结细胞(慢反应细胞)的动作电位 for computer software engineering GB/T50314-2000 of electrical installations code for construction and acceptance of GBJ232- 92 intelligent building weak design construction figure set GJBT-471 2. system description this times engineering weak design including: hours a Kok information facilities system integrated wiring system (containing room network, communications part) wired TV system information guide and the released system hours II Kok public security system fire automatically alarm system (containing public broadcast part) security technology prevention system security monitoring system out entrance control system car library management system hours three Kok building equipment monitoring system hours four Kok information application system queued station ICU visitation system operation the system monitoring and training system call intercom system hours, five hours Kok Kok intelligent integrated system of information system (1) cabling systems (including computer room network, communication component) computer network systems and voice communications systems Center of information on medical floor computer room located in the engine room. Voice communication system using a local telecommunications operator providing voice service, configuration-independent integrated services digital program-controlled switchboards. Operators providing communications ... If any compatibility requirements, by way of increased access to the Communications Board within the chassis to meet 右:心室肌细胞(快反应细胞)的动作电位 心肌细胞的兴奋性受下列因素影响: ?膜电位:膜电位低于-55mV时,任何强度的刺激均不能使心肌细胞兴奋(或应激),膜电位-55mV,-80mV间,强于阈值的刺激才能引起细胞部分或完全除极;其中-55mV,-60mV间细胞部分除极产生的兴奋不能传布至邻近细胞。-60mV,-80mV间,细胞除极产生的兴奋虽可传布,但与正常相比,位相0除极慢、振幅低,且动作电位时限短,因而应激性低,传导速度慢。心肌细胞除极后,其兴奋性随复极程度而改变,膜电位恢复至-55mV前为绝对不应期,膜电位恢复至-60mV前为有效不应期,-55mV,-80mV间为相对不应期(图3)。相对不应期开始前有一个短暂的易惹期(或称易损期),在此期间外来刺激易形成折返和异位心律。 慢反应细胞的不应期可延续至复极完毕之后。动作电位时限延长时,不应期相应地延长。心率缓慢、低钾和奎尼丁类药物作用使动作电位时限延长,也使不应期相应延长。 ?膜反应性:不同膜电位时心肌细胞的除极反应,称为膜反应性,可用膜反应曲线表示(图3)。在同一膜电位,心肌细胞位相0除极速度快且振幅高的,膜反应性强,兴奋性高,其膜反应曲线左移;反之,则膜反应性弱,兴奋性低,膜反应曲线右移。 ?静止膜电位与阈电位间差距:心肌细胞静止膜电位接近阈电位时,兴奋性高;反之,则兴奋性低。 3.传导性 心肌细胞有将冲动传布到邻近细胞的性能,称为传导性。影响传导的因素有:?被传冲动的有效程度(动作电位位相0除采速度与振幅);?接受冲动的心肌细胞的应激性;?心肌纤维的物理性能,如对冲动传布的阻力,后者受纤维直径,纤维走向与结构的一致性以及细胞间闺盘大小与分布等因素影响。若冲动本身的有效程度高,接受冲动的心肌细胞应激性也高,或心肌纤维直径大且走向和结构一致,闺盘阻力小,则传导速度快;反之,传导缓慢。房室结细胞位相0除极速度慢、振幅低,结内心肌纤维走向与结构不一致,因而冲动传导缓慢,且容易发生传导障碍。 心脏各部分有迷走和交感神经节后纤维分布,迷走神经主要分布在窦房结、心房、房室结和希司束近端,通过释放乙酰胆碱减慢位相4除极速度,从而降低窦房结的自律性,导致潜在起搏点除极。迷走神经还能缩短心房肌的不应期,延长房室结的不应期,导致相应的传导异常。交感神经分布到心脏各部,窦房结和房室结内较丰富,通过释放去甲肾上腺素使窦房结和异位起搏点的自律性增高,不应期缩短,冲动传导加速。右星状神经节主要支配窦房结和心房,而左星状神经节主要支配心室。 影响心率、心律导致心律失常的其它因素尚有激素(肾上腺皮质和髓质激素、甲状腺激素、脑垂体激素等)、电解质(主要为钾、钠、钙、镁)、血酸碱度以及氧和二氧化碳张力等的变化。 for computer software engineering GB/T50314-2000 of electrical installations code for construction and acceptance of GBJ232- 92 intelligent building weak design construction figure set GJBT-471 2. system description this times engineering weak design including: hours a Kok information facilities system integrated wiring system (containing room network, communications part) wired TV system information guide and the released system hours II Kok public security system fire automatically alarm system (containing public broadcast part) security technology prevention system security monitoring system out entrance control system car library management system hours three Kok building equipment monitoring system hours four Kok information application system queued station ICU visitation system operation the system monitoring and training system call intercom system hours, five hours Kok Kok intelligent integrated system of information system (1) cabling systems (including computer room network, communication component) computer network systems and voice communications systems Center of information on medical floor computer room located in the engine room. Voice communication system using a local telecommunications operator providing voice service, configuration-independent integrated services digital program-controlled switchboards. Operators providing communications ... If any compatibility requirements, by way of increased access to the Communications Board within the chassis to meet [心律失常的发生原理] 大量单细胞、游离肌肉条和动物心脏电生理研究的结果显示,心律失常有多种不同发生机制,如折返、自律性改变、触发激动(后除极引起)和调变的平行收缩等。然而,由于条件限制,目前能直接对人在体心脏研究的仅限于折返机制,临床检查尚不能判断大多数心律失常的电生理机制,更不能区别心律失常的离子流机制。 表1 心律失常的发生原因 冲动发生异常 冲动传导异常 冲动发生与传导异常 1.自律性异常 1.传导减慢与阻滞(窦房阻1.平行收缩 正常自律性 滞、房室阻滞等 2.4相除极导致传导减慢 异常自律性 2.单向阻滞与折返 2.触发激动 3.传导阻滞,电张电流传导 早期后除极 与反射 延迟后除极 心律失常的电生理机制主要包括冲动发生异常、冲动传导异常以及二者联合存在(表1)。冲动发生异常见于:?正常自律性状态,正常起搏点(最高与潜在起搏点)位相4除极过快或过慢。?异常自律性状态,正常无自律性的快反应细胞(心室和心房肌),以及正常具自律性的快反应细胞(浦顷野纤维)由于病变使膜电位降低达-50,-60mV时,均出现异常自律性,前者由无自律性转为具自律性,后者则自律性增高(图5)。?一次动作电位后除极触发激动(图6,7)。 图5 心律失常发生原理——冲动发生异常 一、正常自律性 A:窦房结第4相除极、加速或减慢 B左:浦顷野纤维第4相除极 二、异常自律性 B右:浦顷野纤维膜电位下降至-60mV,自律性增强 C左:正常心房或心室肌无自律性 C右:当膜电位下降至-60mV,出现异常自律性 图6 心律失常发生原理-后除极触发导致冲动发生异常 for computer software engineering GB/T50314-2000 of electrical installations code for construction and acceptance of GBJ232- 92 intelligent building weak design construction figure set GJBT-471 2. system description this times engineering weak design including: hours a Kok information facilities system integrated wiring system (containing room network, communications part) wired TV system information guide and the released system hours II Kok public security system fire automatically alarm system (containing public broadcast part) security technology prevention system security monitoring system out entrance control system car library management system hours three Kok building equipment monitoring system hours four Kok information application system queued station ICU visitation system operation the system monitoring and training system call intercom system hours, five hours Kok Kok intelligent integrated system of information system (1) cabling systems (including computer room network, communication component) computer network systems and voice communications systems Center of information on medical floor computer room located in the engine room. Voice communication system using a local telecommunications operator providing voice service, configuration-independent integrated services digital program-controlled switchboards. Operators providing communications ... If any compatibility requirements, by way of increased access to the Communications Board within the chassis to meet 程序刺激(?)与次后触发激动引起的自发除极,注意后除极波逐渐增高达阈电位后导致持续快速心律失常,最终后除极降至阈电位以下,快速心律失常终止 图7 早期后除极与延迟后除极触发导致冲动发生异常(触发激动) 临床上正常自律性状态下冲动发生异常所致心律失常包括窦性心律失常和逸搏心律;异常自律性可致加速的房室交接处或心室自主节律,平行收缩,房性或室性快速心律失常。后除极是发生在前一次动作电位复极过程中或复极完毕后的阈值下除极,分别称为早期后除极(EAD)和延迟后除极(DAD)。后除极达慢反应细胞除极阈值时,可引起一次或连续除极。EAD发生在不同原因所致心肌细胞复极过程显著延长时,如细胞外钾离子浓度增高,普鲁卡因胺、高浓度儿茶酚胺药物作用以及浦顷野纤维机械或牵拉性损伤等;而DAD则与洋地黄素性作用或其它原因导致细胞内钙离子增高有关。程序刺激可诱发和中止后除极激动所致心致过速,临床电生理尚不能明确区分心律失常的折返或触发激动机制。触发激动可能引起房性或室性快速心律失常,其临床意义和发生率尚在探索中。 冲动传导异常多由心肌细胞膜性能改变如动作电位振幅和上升速率降低,应激性下降,细胞间接合减少,以致冲动传导减慢或阻滞。可导致潜在起搏点脱逸,亦可引起折返性快速心律失常。折返形成的基本条件为:?心脏某处或多处单向阻滞;?冲动在另一途径传导缓慢;?阻滞部位远端心肌延迟激动;?阻滞部位近端心肌再激动。心脏内不均匀的传导抑制,使邻近心肌的应激性和不应期极不一致时,局部心肌内可形成电生理性能显著不同的两条传导途径。这两条途径是有共同的近端和远端通道。在合适条件下,冲动自近端共同通道沿两条途径之一传向远端共同通道,继而经另一途径由远端再次传入近端共同通道,形成冲动传导的一次或多次折返,折返可沿固定解剖或电生理传导障碍,在单向阻滞和传导减慢具备的条件下形成;也可呈围绕不激动心肌中心区的传导涡(微折返——leading circle学说);还可表现为跨过不能应激的心肌间隙的电张电流逆传(反射—reflection)。(图8、9、10)。 图8 心律失常发生原理——单向阻滞与折返 左上 浦顷野纤维分支与心室肌间折返 下 心室肌内电生理性能分离形成局部折返 for computer software engineering GB/T50314-2000 of electrical installations code for construction and acceptance of GBJ232- 92 intelligent building weak design construction figure set GJBT-471 2. system description this times engineering weak design including: hours a Kok information facilities system integrated wiring system (containing room network, communications part) wired TV system information guide and the released system hours II Kok public security system fire automatically alarm system (containing public broadcast part) security technology prevention system security monitoring system out entrance control system car library management system hours three Kok building equipment monitoring system hours four Kok information application system queued station ICU visitation system operation the system monitoring and training system call intercom system hours, five hours Kok Kok intelligent integrated system of information system (1) cabling systems (including computer room network, communication component) computer network systems and voice communications systems Center of information on medical floor computer room located in the engine room. Voice communication system using a local telecommunications operator providing voice service, configuration-independent integrated services digital program-controlled switchboards. Operators providing communications ... If any compatibility requirements, by way of increased access to the Communications Board within the chassis to meet 右上 房室结内纵形电生理性能分离所致折返 下 心肌束内邻近纤维电生理性能分离所致折返 图9 反射——电张电流递传引起的折返 上:置于浦顷野纤维不应激段近端与远端电极记录到的跨膜电位 下右:近端冲动在不应激段传导受阻,但形成的电张电流使冲动缓慢传导至远端 下中:近端冲动在不应激段受阻,形成的电张电流不足以引起远端激动 下左:近端冲动经电张电流延迟传导至远端,递传至近端,产生第2次动作电位——反射 图10 心律失常发生原理——可能为折返环部位 1.右房内 窦房结,心房交界;2.左房内;3.房室结内;4.经旁道房室折返;5.经希氏浦顷野系统束支折返;6.心室肌内 临床上有充分依据提示房室结性心动过速和房室旁道所致室上性心动过速的机制为折返,其折返途径分别为房室结内双通道和经心房、房室结、希浦系统和心室再经旁道逆转回心房的折返环。不少室上性和室性快速心律失常的机制是心房和心室内微折返(表2)。 for computer software engineering GB/T50314-2000 of electrical installations code for construction and acceptance of GBJ232- 92 intelligent building weak design construction figure set GJBT-471 2. system description this times engineering weak design including: hours a Kok information facilities system integrated wiring system (containing room network, communications part) wired TV system information guide and the released system hours II Kok public security system fire automatically alarm system (containing public broadcast part) security technology prevention system security monitoring system out entrance control system car library management system hours three Kok building equipment monitoring system hours four Kok information application system queued station ICU visitation system operation the system monitoring and training system call intercom system hours, five hours Kok Kok intelligent integrated system of information system (1) cabling systems (including computer room network, communication component) computer network systems and voice communications systems Center of information on medical floor computer room located in the engine room. Voice communication system using a local telecommunications operator providing voice service, configuration-independent integrated services digital program-controlled switchboards. Operators providing communications ... If any compatibility requirements, by way of increased access to the Communications Board within the chassis to meet 冲动发生异常合并冲动传导异常时,异位起搏点由于周围传入阻滞保护,不受邻近激动波前方的侵入,始终保持自身的除极规律,形成平行收缩心律。异常冲动发生与冲动传导异常相互作用可改变异常冲动的传入或传出阻滞程度,使异常冲动发生加速、减速、夹带(entrain)或完全抑制,临床上表现为快慢不等的各种心律失常。近年还有报导平行收缩心律时,异常冲动发生的规律受窦性心律改变影响而调变。 表2 各种临床心律失常的可能发生原理 发生原理 临床心律失常 房室结内折返性心动过速、经旁道房室往返性心动过速 折返 持续单形室速,束支折返性室速、房内折返性心动过速 多源性房性心动过速 异常自律性 某些类型的房速和室速 洋地黄毒性反应所致房性、房室交接处性与室性心律和心 动过速 后除极触发激动 加速的交接处性和心室自主节律 某些类型的室速 【预后】 心律失常的预后与心律失常的病因、诱因、演变趋势是否导致严重血流动力障碍有关。发生于无器质性心脏病基础上的心律失常包括过早搏动、室上性心动过速和心房颤动,大多预后良好;但QT延长综合征患者发生室性过早搏动,易演变为多形性室性心动过速或心室颤动,预后不佳;预激综合征患者发生心房扑动或心房颤动且心室率很快时,除易引起严重血流动力改变外,还有演变为心室颤动的可能,但大多可经直流电复律和药物治疗控制发作,因而预后尚好。室性快速心律失常和心率极度缓慢的完全性房室传导阻滞、心室自主节律、重度病态窦房结综合征等,可迅速导致循环功能障碍而立即威胁病人的生命。房室结内阻滞与双束支(三分支)阻滞所致的房室传导阻滞的预后有显著差别,前者预后较好而后者预后恶劣。发生在器质性心脏病基础上的心律失常,如本身不引起明显血流动力障碍,又不易演变为严重心律失常的,预后一般尚好,但如基础心脏病严重,尤其是伴心功能不全或急性心肌缺血者,预后一般较差。 for computer software engineering GB/T50314-2000 of electrical installations code for construction and acceptance of GBJ232- 92 intelligent building weak design construction figure set GJBT-471 2. system description this times engineering weak design including: hours a Kok information facilities system integrated wiring system (containing room network, communications part) wired TV system information guide and the released system hours II Kok public security system fire automatically alarm system (containing public broadcast part) security technology prevention system security monitoring system out entrance control system car library management system hours three Kok building equipment monitoring system hours four Kok information application system queued station ICU visitation system operation the system monitoring and training system call intercom system hours, five hours Kok Kok intelligent integrated system of information system (1) cabling systems (including computer room network, communication component) computer network systems and voice communications systems Center of information on medical floor computer room located in the engine room. Voice communication system using a local telecommunications operator providing voice service, configuration-independent integrated services digital program-controlled switchboards. Operators providing communications ... If any compatibility requirements, by way of increased access to the Communications Board within the chassis to meet
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