心脏记忆的研究现状

心脏记忆是指T波的持续可逆的变化,本文对心脏记忆的研究现状进行论述.     

非阵发性房性心动过速伴Ⅱ°外出阻滞

患者男性,50岁,体检时发现心律失常。3周前有感冒史。心电图(附图)可见形态正常的窦性P,频率68次/分,P-R间期0.15秒。Ⅱ导联可见一系列提前出现的P’-QRS-T波群,P’呈逆行性,P’-P’间距0.47秒—0.50秒,其频率约为120次/分,同时可见异位P_2-P_3’间距是0.96秒,大致相当于异位起搏周期的两倍,故存在Ⅱ°传出阻滞。在R_6之前可见一介于窦性P与房性P’间较为平坦的房性融合波。粗略看来P_3’-P_4’相距2.50秒=0.50秒×5,实际上,应是2.50秒=0.50秒×(2 3)。在aVR可见3个直立的P’波,P2’-P3’间期3.28秒,非0.50秒的整倍数,说明异位灶并无传入保护。在R_3、R_7前面,各有一房性融合渡。心电图诊断:1.窦性心律,2.非阵发性房性心动过速伴Ⅱ°外出阻滞、房性融合波。讨论非阵发性房性心动过速,根据有无窦性     

心率过快的家庭应对法

在正常情况下,心脏的跳动是南起搏和传导系统的最高"司令部"--窦房结发动的,所以叫窦性心律.正常成人的心跳每分钟60～100次,如果超过100次,就是心跳过快,医学上叫作心动过速.引起心动过速的原因有很多,当家人出现心动过速时,我们可以采取哪些应急措施为后期的治疗赢得时间呢?     

急性下壁心肌梗塞并发房室传导阻滞48例临床分析

本文就1978年6月～1984年5月下壁AMI90例,选择其中发病或住院期间并发AVB的48例进行临床分析。一、资料来源和诊断标准资料来源:以上病例均系发病后30分钟至48小时住院病例。男性58例,女性32例。年龄38岁～82岁,平均62.2岁。     

心房颤动新进展国际研讨会纪要

由中华医学会心电生理和起搏学会、中国生物医学工程学会心脏起搏与电生理分会、大连医科大学附属第一医院共同主办，大连医科大学附属第一医院承办的．首次在中国召开的心房颤动(简称房颤)新进展国际研讨会于1997年6月23～24日在大连举行。来自瑞典、美国和全国27个省市(包括台湾省)、102家医院的心血管内、外科知名专家、学者和医师共302人参加。大会收到论文169篇。大会主席陈新教授首先对房颤的研兜现状作了发言，2天中有28人次作了专题发言和论文交流。现将大会的内容简要整理如下。     

先天性QT延长综合征合并阵发性三度房室传导阻滞一例

先天性QT延长综合征（LQTS）患者是心原性猝死的高危人群。LQTS合并房室传导阻滞（AVB）非常少见，而且死亡率高，半年死亡率在50％以上。本文报道1例LQTS合并阵发性三度AVB，在置入起搏器前后反复出现心原性晕厥。     

心房肌的复极与阵发性心房颤动发生机制的实验研究

目的　对在体犬左、右心房肌的复极时间进行研究 ,探讨阵发性心房颤动 (房颤 )发生与维持的潜在机制。方法　记录基础心律、非程序刺激及早搏刺激 (SR、S1 、S2 )时 1 4只犬左、右心房的单相动作电位 (MAP)和有效不应期 (ERP) ,测量每个动作电位的幅度和动作电位时程 [复极达90 %、80 %、5 0 %时的动作电位时程 (ms,APD90 、APD80 、APD50 ) ]。并在记录过程中同时观察房颤的诱发情况。结果　记录满意MAP信号 1 2例 ,共标测 2 6点 (右房 1 7点 ,左房 9点 ) ,MAP振幅平均(6 98± 1 76 )mV ,左心房APD90 和APD50 小于右心房 [(1 5 7 4± 4 3 5 0 )ms比 (1 70 9± 37 9)ms ,P <0 0 5 ;(88 4± 1 9 1 )ms比 (1 0 0 1± 2 1 2 )ms,P <0 0 5 )。其中左房刺激发作 38阵 ,明显多于右房 2 3阵 (P <0 0 5 )。由左房诱发房颤的早搏的偶联间期明显比在右房诱发的短 (P <0 0 5 )。起源于左房的房颤的早搏参数小于起源于右房的 (P <0 0 5 )。结论　左、右心房间具有MAP的异质性的复极特性 ,是诱发折返、发生和维持房颤的基质。     

房室结慢径消融对心房电生理性质的影响

Objective The ablation of the atrioventricular node slow pathway may reduce the inducibility of atrial fibrillation (AF) ,but the mechanisms remain unknown. We tried to investigate the impact of ablation on atria refractory period, and to elucidate the underlying mechanism. Methods Thirty-two patients with atrioventricular node reentrant tachycardia (AVNRT) were enrolled in the study. Atria effective refractory period (ERP) and vulnerable window (VW) at high right atrium (HRA),inferior right atrium (IRA),distal (CSd) and proximal CS (CSp) ,as well as sinus rate (SR) and effective refractory period of fast pathway (FERP) were measured before and after ablation. Results ( 1 ) After ablation, the ERP at HRA did not change:(214. 4 ± 35. 1 ) ms, (213.4 ± 37. 3) ms, P = 0. 6, on the other hand, the ERPs at following sites were significantly prolonged:CSp(218. 1 ±21.8)ms, (235.3 ± 23.6) ms,P ＜0. 0001 ;CSd(230. 9 ±21.0) ms, (244. 7 ±25. 1)ms,P＜0. 01;IRA(198.8 ±26.7)ms,(219.7 ±28. 7) ms,P ＜ 0.005,respectively. (2) The VW of HRA remained unchanged after ablation, while the VWs of CSp, CSd and IRA trended to decline despite no statistic significant. (3)SR showed a little increasing but without statistic significant after ablation (P = 0. 17 ).(4) ERP of fast pathway was significantly decreased after ablation: ( 391 ± 55 ) ms, ( 369 ± 78 ) ms, P ＜ 0. 01.Conclusions The decrease of ERPs at CS and IRA, as well as F-ERP after ablation may decline the inducibility of atrial fibrillation and indicates regional vagal denervation to the atrium.     

肺静脉电隔离对阵发性心房颤动患者P向量环的影响

目的探讨成功的肺静脉电隔离对心房除极的影响。方法记录接受环肺静脉电隔离术的18例阵发性心房颤动(PAF)患者术前及术后第1天窦性心律时的心向量图。测量P环的运行时间、P向量环在正交导联额面(F)、水平面(H)、左侧面(LS)的最大振幅及方向。同时记录P环从运行开始后每10ms的除极振幅。结果肺静脉隔离术后P环F最大振幅较术前降低(0.109±0.038mVvs0.128±0.040mV,P0.05)。P环运行时间,H及LS的最大振幅,F、H、LS的最大振幅方向,术前术后无差异(P0.05)。消融成功组(n=12)术后P环H最大振幅较术前降低(0.092±0.019mVvs0.122±0.030mV,P0.05),而术后复发组(n=6)则无明显变化。肺静脉隔离术后P环振幅降低发生在P环运行至40～80ms的部分,即P向量环的中部。结论PAF病人在肺静脉电隔离成功后P环最大振幅发生改变。     

心房肌复极的电整复性与阵发性心房颤动发生机制的实验研究

Objective Electrical restitution was believed to be a determinant responsible for the stability of heart rhythm. Although numerous studies focused on the role of action potential duration restitution (APDR) in the initiation and maintenance of ventricular fibrillation (VF), the relationship between atrial APDR and atrial fibrillation (AF) has not been fully understood. This study aims to investigate the characteristics of APDR of left atrium (LA) and right atrium (RA) in canines and the relevance to induction of AF. Methods Monophasic action potential (MAP) was recorded from LA and RA in 14 canines using the MAP recording-pacing combination catheter. APDR, plotted as action potential duration (APD) on the preceding diastolic interval (DI), was assessed by use of programmed stimulation with a single extrastimulus (S_1S_2) at LA and RA. Episodes of AF were recorded and analyzed. Results APD_(90) was significantly shorter in the LA than that in the RA [( 157.4 ± 43.5 ) ms vs. ( 170. 9 ± 37. 9)ms, P < 0. 05]. The mean slope of the APDR curve by S_1S_2 in the LA was significantly greater than that in the RA ( 1.3 ±0. 4 vs. 0. 9 ± 0. 3, P < 0. 05 ). The incidence of induced AF was significantly higher in the LA than in the RA (11/18 vs. 7/18, P < 0. 05). Conclusions The APDR and MAP characteristics are not uniform between atriums, which may be one of the important mechanisms responsible for the initiation of AF. Heterogeneity of APDR between LA and RA might create critical gradients or a dispersion of repolarization and subatrate for re-entrant arrhythmias and vulnerability to AF.