钾离子浓度对氟卡尼作用下兔左室电-机械活动的影响  

Effects of potassium level on flecainide action in electrical and mechanical activities of rabbit left ventricle

作　　者：张雪梅 董亚玲[1] 李云云 杨琳 薛小临[1] 严干新[3] ZHANG Xue-mei;DONG Ya-ling;LI Yun-yun;YANG Lin;XUE Xiao-lin;YAN Gan-xin(Department of Cardiology,First Affliated Hospital,School of Medicine of Xi′an Jiao Tong University,Xi’an 710061,Shaanxi,China;General Hospital of Ningxia Medical University,Yinchuan 750000,Ningxia,China;Main Line Health Heart Center,Wynnewood,PA 19096,USA)

机构地区：[1]西安交通大学第一附属医院心内科,教育部环境与疾病相关基因离子通道病重点实验室,陕西西安710061 [2]宁夏医科大学总医院,宁夏银川750000 [3]Main Line Health Heart Center,Wynnewood,PA 19096,USA

出　　处：《中国心脏起搏与心电生理杂志》2021年第4期351-355,共5页Chinese Journal of Cardiac Pacing and Electrophysiology

摘　　要：目的探讨不同细胞外钾离子浓度环境下氟卡尼对离体兔左室心肌电活动及收缩力的作用情况.方法建立经冠状动脉灌注兔左室楔形组织块标本,施加基础刺激周长(BC L)为2000、1000、500 ms的电刺激,设立对照组:给予钾离子浓度为3.5 mmol/L的台氏液灌注;实验组:分别给予钾浓度(3.5、5.5、7.0 mmo/L)+氟卡尼浓度(10μmol/L)灌注,观察离体兔左室QRS波时限、QT间期、Tp-e间期、心肌收缩力等受影响情况.结果氟卡尼可使QRS波时限延长(P<0.05)且该现象呈快频率依赖性(P<0.01);随K^(+)浓度升高,氟卡尼的上述作用被明显放大甚至出现文氏脱漏现象,QT间期、Tp-e间期未受明显影响.在一定刺激频率范围内,心肌收缩力随刺激频率的增加而增强(P<0.001),即收缩力的"正阶梯效应".氟卡尼作用下心肌收缩力及正阶梯效应均减弱(P<0.001);随K+浓度的升高,氟卡尼负性肌力作用增强,正阶梯效应进一步减弱甚至被反转.结论随细胞外K+浓度增加,氟卡尼对兔左室心肌兴奋性及传导性的阻滞、快频率依赖作用以及负性肌力作用均被放大,高钾时,心肌收缩力正阶梯效应消失甚至可能被反转.Objective To investigate effects of potassium level on flecainide action in electrical and mechanical activities of rabbit left ventricle.Methods Isolated arterially perfused rabbit left ventricular wedge preparations were stimulated at basic cycle lengths(BCL)of 2000,1000,500 ms.The preparations perfused with Tyrode′s solution(K+3.5 mmol/L)were set as control group,the preparations perfused with Tyrode′s solution(K+3.5,5.5,7.0 mmol/L)mixed with flecainide(10μmol/L)were set as trial groups.The transmural ECG,cardiac contractility were recorded and QRS duration,QT interval,Tp-e interval were measured.Results QRS duration significantly prolonged after flecainide perfused(P<0.05)and the role showed strong manner of fast rate-dependent conduction block(P<0.01,P<0.001).With the increasing concentration of potassium,the role of flecainide on conduction delay was obviously amplified,even conduction block happened.Cardiac contractility:The cardiac contractile force was increased progressively at shorter BCL without flecainide perfused(P<0.001),the role was known as the force-frequency relationship.Both contractility and the force-frequency relationship were significantly reduced after flecainide perfused(P<0.001).With the increasing concentration of potassium,the negative inotropic action of flecainide became more obvious as well as the force-frequency relationship became more weaker and even disappeared or reversed with high concentration of potassium.Conclusions With the increasing concentration of potassium,the role of flecainide in electrical activity conduction bloke and negative inotropic action are amplified,even the force-frequency relationship may reversed with high concentration of potassium in rabbit left ventricule.

关 键 词：电生理学 氟卡尼 钾离子 传导性 收缩力 

分 类 号：R331.38[医药卫生—人体生理学]