心房间传导通道与房性心律失常

由于心房独特的形态和复杂的解剖结构 ,关于心房内冲动传导模式的争论持续了半个多世纪 ,至今有些观点需要研究与验证。　　 1910年 L ewis等 [1 ] 确定窦房结为心脏起搏点后 ,观察到冲动在心房内传导呈“宽道传播 (broad pathways)”,而未发现心房肌间传导有“窄道 (narrow tracts)”现象 ,因此提出心房冲动传导的基本模式 :普通心房肌传导。同期 Thorel[2 ]、Wenckebach[3 ] 、Bachmann[4] 等人的研究提示在窦房结与房室结间 ,窦房结与心房间 ,右心房与左心房间存在着优势传导束。 196 3年 Jam es[5 ] 总结并发展前人的理论 ,提出心房的…     

不连续性传导在房性心律失常中的作用

在离体心肌进行的多电极标测、光学标测及正常和异常心肌组织学的分析表明[1] ,由心脏各向异性所致的心脏传导的不连续性在心律失常的发生中起着重要的作用。人们已将目光由基础研究移向临床 ,寻找快速心律失常时不连续性传导作用的“足迹”(ｆｏｏｔｐｒｉｎｔ) ,这种“足迹”包括记录到的碎裂电位 ,其提示心肌存在不均一的各向异性传导。因为碎裂电位反映的是沿阻滞线的传导 ,提示不连续性传导的存在。本文讨论不连续性传导在各种房性快速心律失常中的作用 ,心房电生理特性的异常可能源于解剖结构的异常。一、不连续性传导在房扑中的作用…     

心房阻滞与房性心律失常

1概述 正常窦性激动自右心房沿着三条结间束顺传至房室结,同时又较快地沿着上房间束（Bachmann束）传向左心房,当结间束和（或）房间束发生传导障碍时称为心房阻滞或结间阻滞。按阻滞发生部位可有左心房阻滞和右心房阻滞,以前者较多见,心房阻滞虽无血流动力学上的意义,却易诱发房性心律失常,据报道约有半数患者伴有反复发作的阵发性心房颤动或心房扑动史,     

心房扩大与房性快速心律失常关系分析

目的为进一步探讨房性快速心律失常发病机理。方法采用多普勒超声心动图和动态心电图检查方法对１５０例心血管病人心房扩大和房性心律失常发生情况进行分析。结果左心房扩大为主者房性快速心律失常发生率（７１．９３％）显著高于右心房扩大为主者（２０．００％）和心房内径正常者（１４．２９％）,Ｐ〈０．０１;心房内径扩大越明显,房性快速心律失常的发生率越市,性质越严重;即便是程度相同的左心房扩大者,二尖瓣狭窄为主的     

超常与伪超常期传导现象

1924年Lewis和Master首先提出临床超常(期)传导现象，以后文献中屡有报道。1968年Moe等发现，不少所谓超常传导还可以用生理学和解剖学理论加以解释，而并非真正的超常传导，故将其统称为伪超常传导现象。兹分述如下。     

双心房起搏治疗房性快速心律失常疗效探讨

2例患者均为男性 ,年龄分别为 71岁和 72岁。诊断为病态窦房结综合征 ,慢 -快型 ,分别由高血压病和冠心病引起。心电图或动态心电图为房内阻滞 ,阵发性心房颤动 (房颤 )、心房扑动 (房扑 )、房性早搏 (房早 ) ,间有窦性心动过缓 ,窦性停搏。房颤发作频繁 ,每天 >1次 ,口服多种抗心律失常药物效果较差。均植入 Medtronic796 4i型具有自动方式转换(AMS)的 DDD起搏器。冠状静脉窦导线为 2 188型专用双极导线 ,转接器选用 5 86 6 - 38M- Y型转接器。冠状静脉窦电极导线植入冠状静脉窦中部或远端。冠状静脉窦电极导线与转接器阳极相连 ,右心…     

超常传导还是"伪超常传导"

我对“房室交界区超常传导一例”一文中心电图的分析持有不同看法，特此提出质疑，并讨论。     

双心房同步起搏治疗房性心律失常

双心房同步起搏(AAT)不仅能保证房性心率较慢时,起搏器同步起搏左右心房,且在左房或右房出现早搏时,能及时触发另一心房起搏,达到双房持续性同步除极和复极,能有效预防房早诱发的折返性房性心律失常。本院对2例阵发性房颤伴房间传导阻滞者行双心房同步起搏,取得较好疗效。     

心房梗死与室上性心律失常

心房梗死与室上性心律失常何秉贤心房梗死（ａｔｒｉａｌｉｎｆａｒｃｔｉｏｎ，ＡＩ），据尸检研究，可占到整个心梗者的７～１７％［１］，常与左室梗塞伴存。伴有ＡＩ者可发生心房破裂和各类房性心律失常，所以，提高临床认识水平很重要。ＡＩ在右房比左房更多见，位于...     

心房传导阻滞致快速房性心律失常的心电图特点

阵发性房性心动过速和心房颤动是 1组常见的心律失常 ,其发生机制尚不完全清楚 ,近年来一些学者认为心房传导阻滞在快速房性心律失常的发生过程中起重要作用 ,作者近来遇到 15例房内传导阻滞伴快速房性心律失常的患者 ,并观察了心电图和临床特点 ,旨在进一步深入了解和认识房内传导阻滞的临床意义。1　资料与方法15例中男 10例 ,女 5例 ,年龄 (60 .1± 11)岁。临床诊断冠心病 6例 ,高血压病 3例 ,病窦综合征 3例 ,心肌炎 1例 ,原因不明 2例。本组患者均记录心电图 ,并询问病史 ,有房内传导阻滞心电图表现并房性快速心律失常者被选入本组 ,除…     

"Supernormal" Conduction and Excitability

"Supernormal" Conduction and Excitability. Electrocardiograph manifestation of "supernormal" conduction is defined as conduction that is more rapid than expected or presence of conduction when block is anticipated. It is not supernormal in the sense of being more rapid than normal. Therefore, the term relative supernormality or "supernormality" is more appropriate. The mechanism of "supernormal" conduction is conduction during a period of supernormal excitability and conduction associated with altered membrane potential. Some of the more common phenomena that are not dependent on conduction during the supernormal period but manifest better than expected conduction, thus simulating "supernormal" conduction, include dual AV nodal conduction, the "gap" phenomenon, "peeling back" of the refractory period, summation of subthreshold responses, diastolic phase 4 depolarization, and phasic autonomic influences.     

VVI起搏术后心房颤动与心钠素和室房逆传的关系

长期心脏起搏的患者,有部分并发心房颤动,尤其是VVI起搏者。本文主要阐述VVI起搏术后心房颤动与血心钠素和室房逆传的关系,为选择适当的起搏器和起搏方式以及临床干预措施提供理论依据,从而减少起搏术后心房颤动的发生。     

缝隙连接与心律失常的研究现状

细胞之间动作电位或兴奋传导称为胞间传导。可兴奋细胞间的电耦联是通过一种特殊的胞间结构来实现的,这种结构即是缝隙连接。现已证实心脏的正常传导和引起心律失常的异常传导都与缝隙连接直接相关。     

Supernormal conduction and atrial echo beats in the dog

The occurrence of the supernormal conduction phenomenon duringthe vulnerable period, overriding phase 3 of the action potentialand the relative refractory period, suggests that it could playa significant role in the asynchrony of conduction and inducereetrant arrhythmias. To support this hypothesis, the evolutionof the supernormal conduction phenomenon, the echo beats inducedby atrial stimulation, the monophasic action potential (MAP_a),the effective (ERP) and functional refractory periods (FRP)and the ratio ERP/MAP_a have been studied under the influenceof disopyramide which reduces the supernormal conduction phenomenon.Three groups of dog were evaluated: control, sympathectomizedand atropinized dogs. MAP_a duration was not modified in eithergroup and the FRP lengthened in all groups irrespective of whetheratrial echo beats persisted or not. The ERP and the ERP/MAP_aare more specific. The supernormal conduction phenomenon isthe factor that follows the evolution of the echo beats withthe most accuracy: it diminished or disappeared in all casesin which the echo beats disappeared. It was not modified in80% of the cases where the echo beats persisted; there was a‘grey-zone’ in which one-third of the cases witha reduction of less than 75% of the supernormal conduction phenomenonshowed the persistence of echo beats: there is probably a criticalpoint in that zone where there is enough regression of thisphenomenon to prevent echo beats.     

老年人高血压左室肥厚与心律失常关系的研究

目的探讨老年人高血压左室肥厚(LVH)与心律失常的关系。方法对178例老年高血压患者进行超声心动图及Holter检查,比较有LVH及无LVH两组各类心律失常的发生情况。结果178例老年高血压患者并发LVH81例(45·5%),LVH组各种心律失常的发生率与非LVH组比较,差别均有显著性意义(P<0·01),LVH组复杂性室性心律失常(CVA)为39例(48·1%),显著高于无LVH组的17·5%(17例)(P<0·01)。结论老年人高血压LVH与心律失常的发生有密切关系,且与CVA成正相关。     

The Relationship Between Sinoatrial Conduction Time and Sinus Cycle Length Revisited

In 1974 we reported an inverse relationship between sinoatrial conduction time (SACT) and sinus cycle length (SCL) during sinus arrhythmia utilizing the indirect atrial premature stimulation technique for estimating SACT, However, this behavior seemed anomalous try analogy with the AV node. Subsequent to 1974, methodological considerations about and limitations of the indirect techniques for estimating SACT became apparent, making us question our former impression. When the capability to directly record sinus node electrograms was developed and established in the 1980s, we had the means to reevaluate the SACT/SCL relationship. This report presents our findings in 40 patients: the SACT/SCL relationship is direct, not inverse. Moreover, we also show that during the phasic fluctuations of sinus arrhythmia, the P-P alterations are initiated more frequently by changes in sinoatrial conduction time than by changes in sinus cycle length.     

Atrial Conduction Disorders

Atrial conduction disorders result from impaired propagation of cardiac impulses from the sinoatrial node through the atrial conduction pathways. Disorders affecting interatrial conduction alter P-wave characteristics on the surface electrocardiogram. A variety of P-wave indices reflecting derangements in atrial conduction have been described and have been associated with an increased risk of atrial fibrillation (AF) and stroke. Interatrial block (IAB) is the most well-known of the different P-wave indices and is important clinically due to its ability to predict patients who are at risk of the development of AF and other supraventricular tachycardias. P-Wave Axis is a measure of the net direction of atrial depolarization and is determined by calculating the net vector of the P-wave electrical activation in the six limb-leads using the hexaxial reference system. It has been associated with stroke and it has been proposed that this variable be added to the existing CHA2DS2-VASc score to create a P2-CHA2DS2-VASc score to improve stroke prediction. P-Terminal Force in V1 is thought to be an epiphenomenon of advanced atrial fibrotic disease and has been shown to be associated with a higher risk of death, cardiac death, and congestive heart failure as well as an increased risk of AF. P-wave Dispersion is defined as the difference between the shortest and longest P-wave duration recorded on multiple concurrent surface ECG leads on a standard 12-lead ECG and has also been associated with the development of AF and AF recurrence. P-wave voltage in lead I (PVL1) is thought to be an electrocardiographic representation of cardiac conductive properties and, therefore, the extent of atrial fibrosis relative to myocardial mass. Reduced PVL1 has been demonstrated to be associated with new-onset AF in patients with coronary artery disease and may be useful for predicting AF. Recently a risk score (the MVP risk score) has been developed using IAB and PVL1 to predict atrial fibrillation and has shown a good predictive ability to determine patients at high risk of developing atrial fibrillation. The MVP risk score is currently undergoing validation in other populations. This section reviews the different P-wave indices in-depth, reflecting atrial conduction abnormalities.     

Retrograde Supernormal Conduction in Concealed Accessory Atrioventricular Pathway Following Catheter Ablation

Supernormal Conduction in Concealed Kent Following Ablation. A case is presented of a 63-year-old woman with a concealed accessory pathway that exhibited retrograde supernormal conduction after radiofrequency catheter ablation. Although ventricular pacing at a slow rate revealed no retrograde conduction over the accessory pathway following ablation, the tachycardia recurred 15 months later. During ventricular pacing there was retrograde 1:1 conduction over the accessory pathway at a fast rate while there was intermittent VA dissociation with rare retrograde conduction at the slower rate. Ventricular extrastimulus testing demonstrated a supernormal conduction zone of the coupling interval. Thus, accessory pathways may exhibit supernormal conduction after catheter ablation. Pacing should be performed at both slow and fast rates to confirm the presence of conduction block following ablation.     

房室顺传和逆传对窦房结功能低下动物模型心房电生理学特性的影响

探讨房室顺传和逆传对窦房结功能障碍时心房电生理特性的影响。选择 6 0只健康新西兰大耳白家兔 ,开胸打开心包膜 ,于上腔静脉与右心耳交界处消融 ,有 5 0只成功建立单纯窦房结功能低下动物模型 ,随机分为心房起搏 (1∶1房室顺传 )组 ,心室起搏组 (又分 1∶1房室逆传组以及非 1∶1房室逆传组 )。观察房室顺传及房室逆传 1,2 ,4h以及 7d后 ,心房有效不应期 (AERP)、心房激动时间 (A2 )和心肌波长指数 (WLI)发生的变化。结果 :心室起搏 ,若存在 1∶1房室逆传 ,AERP缩短 ,A2 延长 ,WLI减小 ;若无 1∶1房室逆传 ,则AERP逐渐延长 ,A2 无明显变化 ,WLI增大。比较 1∶1房室逆传组与非 1∶1房室逆传组发现 ,同时段两组间AERP ,A2 和WLI存在显著性差异。同时发现 ,心房起搏 ,窦房结功能低下模型的AERP延长 ,A2 缩短 ,WLI增大。结论 :房室逆传能增加单纯窦房结功能低下动物模型电不稳定性 ,房室顺传则能抑制单纯窦房结功能低下动物模型心房电紊乱。