房束旁道的电生理特点与Mahaim电位在射频导管消融中的意义

探讨房束旁道的电生理特点与Mahaim电位在射频导管消融 (RFCA)中的意义。 1997年 7月至 2 0 0 3年 1月对 3例拟诊为房束旁道引起的逆向型房室折返性心动过速的患者进行了电生理检查和RFCA。男 2例 ,女 1例 ,年龄分别为 18,2 3,2 5岁。心动过速发作史 7～ 16年 ,频率 180～ 2 30次 /分 ,发作时均有明显心悸 ,其中 1例伴头晕、胸闷。窦性心律时心电图 1例正常 ,另 2例示轻微预激。食管心房调搏与心房程序刺激均易诱发心动过速 ,心动过速时体表心电图呈宽QRS波形。 3例均在三尖瓣环右后侧壁标测到的Mahaim电位处 ,于窦性心律及心房起搏下放电消融。 2例彻底阻断旁道前向传导 ,另 1例反复放电未阻断旁道 ,但重复术前程序刺激心动过速不再诱发。分别随访 5年、2年、6个月心动过速均未复发。结论 :RFCA治疗房束旁道介导的心动过速安全有效 ,Mahaim电位在RFCA中具有重要指导价值。     

预激综合征患者多旁路的射频消融

１７４例预激综合征患者中１３例（７．５％）具有多旁路（２９条）。２９条旁路中２１条由基础电生理检查证实，８条在阻断其它旁路后显现。４例在双侧，９例在单侧消融。平均放电３２±１４次后将２７条（９３．１％）旁路阻断。多旁路与单旁路消融成功率相似（９３．１％ＶＳ９４．０％，Ｐ＞０．０５）；但放电次数多（３２±１４ＶＳ１４±１１，Ｐ＜０．０５），消融时程长（３．６±０．８ｈＶＳ２．１±０．９ｈ，Ｐ＜０．０１）；多旁路组复发率高（７．６％ＶＳ１．９％，Ｐ＜０．０１）．本研究证实射频消融是根治多旁路患者的有效方法。     

Radiofrequency Catheter Ablation of Accessory Pathways:

RF Catheter Ablation of APs. Catheter ablation techniques are now advocated as the first line of therapy for arrhythmias caused by accessory pathways (APs). The most common energy source is radiofrequency current, but technical characteristics vary. Several parameters can be used to determine the optimal target site: AP potential, AV time, atrial or ventricular insertion site, or unipolar morphology. Specific considerations are needed depending on AP location. Despite the different approaches described, there is no significant difference in the reported success rate, which is over 90%. However, the number of radiofrequency applications needed to achieve ablation appears to differ significantly, with median values from 3 to 8 reported. A combination of criteria related to both timing and direction of the activation wave-front or use of subthreshold stimulation could improve the accuracy of mapping. In patients with "resistant" APs, different changes in ablation technique must be considered during the procedure to achieve elimination of AP conduction. The incidence of complications in multi-center reports is close to 4%, with a recurrence rate of 8%. The long-term safety of catheter ablation requires further study.     

冠状静脉内导管射频消融治疗后间隔心外膜房室旁道的临床研究(附17例报告)

对 17例后间隔旁道的体表心电图特征、电生理特性及导管射频消融术方法学进行分析和探讨。男 11例、女6例 ,年龄 41± 2 4(11～ 73)岁。与后间隔心内膜旁道相比 ,后间隔心外膜旁道的体表心电图有其自身的特点。 17例患者 ,射频消融成功 16例 ,成功率 94%。 7例在冠状静脉窦内消融成功 ,8例在心中静脉内消融成功 ,1例在冠状静脉窦巨大憩室颈部消融成功 ,1例未成功。 17例手术时间 140± 87(86～ 180 )min ,X线曝光时间 42± 2 9(30～ 6 6 )min。 16例随访 1～ 2 4个月 ,无一例心动过速复发。结论 :在冠状静脉内消融成功的后间隔旁道具有一些特定的体表心电图特征。常规在左右侧间隔部标测无满意靶点且试放电无效时 ,应考虑为后间隔心外膜旁道 ,在冠状静脉内标测消融具有较高的成功率 ,能明显缩短手术时间和X线曝光时间 ,无并发症。     

射频消融治疗预激综合征失败病例分析

以射频消融３０７例预激综合征患者，２４例未成功，前、中、后各百例内失败者各占１４，６和４例，成功率分别为８６％、９４％和９６．４％（１０３／１０７）．９例行二次消融成功。初期消融失败的主要原因为导管操作不熟练和旁路定位不精细。中、后期则主要原因为未准确识别某些特殊部位如后间隔及右游离壁旁路的局部电图特征。表明操作者的经验与成功率密切相关。     

经冠状静脉窦射频消融心外膜旁道

报道 13例左侧心外膜旁道的特点和经冠状静脉窦射频消融的结果。 13例左侧旁道患者先经心内膜标测和消融 ,如不成功改由经冠状静脉窦标测 ,记录到旁道电位或最早激动的V波或逆传A波即进行消融。结果 :13例患者全部成功 ,平均放电 1.5± 0 .6次 ,能量 2 1± 4W ,时间 2 1± 9s。成功消融靶点 :左侧游离壁 2例、左后间隔冠状静脉窦憩室 4例、心中静脉 7例。 11例有效靶点均标测到振幅较大的旁路电位 ,其振幅大于A波和V波 ,与二者之比均大于 1。结论 :冠状静脉窦标测到振幅较大的旁道电位是左侧心外膜旁道的重要标志 ;冠状静脉窦消融可以有效地阻断心外膜侧旁道     

Right Posterior Atrioventricular Ring: A Location For Different Types of Atrioventricular Accessory Connections

We present an unusual case of a 28-year-old female patient with recurrent episodes of tachycardias due to participation of two accessory connections located in the posterior tricuspid annulus. Both connections were of the atrioventricular type, the one with non decremental fast conducting properties at the right posteroseptal area, the other with node-like properties at the posterolateral tricuspid ring. Both pathways were successfully ablated transvenously with radiofrequency energy application at the same session. Implications about a common embryological origin of the two pathways as well as review of the literature for similar cases are presented.     

经冠状静脉窦标测和消融后间隔心外膜房室旁道

报道心外膜房室旁道的特点和经冠状静脉窦射频消融术的结果。3例后间隔显性房室旁道患者先经心内膜标测和消融,不成功后改由经冠状静脉窦内标测和消融。术中冠状动脉造影,观察冠状静脉窦形态。结果: 2例冠状静脉窦近端有一憩室,并在憩室的颈部消融阻断房室旁道。成功靶点图为标测到振幅较大的旁道电位,其振幅大于A波和V波。结论:经心内膜标测和消融失败的旁道可能是心外膜旁道,行冠状静脉窦内标测与消融可有效阻断旁道,冠状静脉窦憩室与后间隔旁道可能存在着解剖关系。     

射频消蚀治疗预激综合征81例报告

以射频电流对81例预激综合征伴阵发性室上性心动过速患者的房室旁路进行消蚀。76例(93.8％)患者的83条旁路(94.3％)被阻断。平均放电12次,平均消蚀时程2.3小时,随访7个月,2例(2.5％)复发但成功地进行第二次消蚀,无严重并发症。     

双房室旁道合并Mahaim纤维(附一例分析)

报道１例束室纤维合并双房室旁道的电生理表现。患者有心动过速史１５年，心电图示右侧游离壁显性旁道，分别于三尖瓣环８点半和５点半处消融阻断旁道，原心电图发生了改变，但存在Ｄｅｌｔａ波。上述两条旁道消融前，ＰＲ间期均为０．０６ｓ，心房递增刺激Ｄｅｌｔａ波增大，房室传导无文氏现象。两条房室旁道消融后，ＰＲ间期为０．１０ｓ、ＡＨ间期１００ｍｓ、ＨＶ间期２０ｍｓ。心房递增刺激时ＡＨ间期逐渐延长且出现文氏型房室阻滞，ＨＶ间期不变、预激程度不变，提示为Ｍａｈａｉｍ纤维（束室支）。心室刺激时逆传Ａ波在Ｈｉｓ束电图最早，提示Ｈｉｓ束逆传。三尖瓣环上未能标测到Ａ、Ｖ波融合。心房、心室刺激未能诱发心动过速。     

利用单极标测在心房颤动时消融显性房室旁道

对12例预激综合征患者在心房颤动时以单极标测指导消融房室旁道，其中左侧显性旁道9例、右侧显性旁道3例。在消融成功的靶点图上，单极标测的心室激动较体表心电图QRS波群显示预激成分最明显的Delta波平均提前46±7ms。全部病例消融成功。平均随访7．9±5．1个月，除1例右侧旁道4个月后恢复旁道前向传导需再次消融外，其余11例常规和动态心电图既未见Delta波，也无房室折返性心动过速和心房颤动发生。结果提示对于心房颤动合并显性房室旁道的患者，采用单极标测，其图形易于迅速辨认、测量方法亦简单，用以指导消融成功率高。     

Inducibility of Atrial Fibrillation Before and After Radiofrequency Catheter Ablation of Accessory Atrioventricular Connections

Inducibility of Atrial Fibrillation. Introduction: The purpose of this study was to evaluate the inducihility of atrial fibrillation in patients with an accessory atriovcentricular connection (AAVC) and to determine if the inducibility of atrial fibrillation is altered after successfulradiofrequency catheter ablation of the AAVC.
Methods and Results: Thirty-seven patients with an AAVC and 36 control patients wereprospectively evaluated using a standardized atrial pacing protocol. The high right atrium waspaced using a 25-beat drive train, 1.5-second intertrain pause, 10-mA pulse amplitude, and 2-msec pulse duration at cycle lengths of 250 to 100 msec, in 10-msec decrements. Pacing wasperformed twice at each cycle length. Thirty patients with an AAVC underwent repeat atrialoverdrive pacing after successful radiofrequency ablation of the AAVC. Atrial fibrillation wasinduced in 26 (70%) patients with an AAVC and 22 (61 %) controls (P = NS). Atrial flutter wasinduced in 26 (70%) patients with an AAVC and 22 (61%) controls (P = NS). The cumulativepercentage of patients with atrial fibrillation/flutter induced at each pacing cycle length was thesame in each group. There was no difference in the duration of atrial fibrillation/flutterbetween control patients and patients with an AAVC. Among the 30 patients who underwentrepeat atrial overdrive pacing after radiofrequency ablation of an AAVC, there was no difference in the inducibility or duration of atrial fibrillation/atrial flutter after ablation compared tobaseline.
Conclusion: These findings indicate that the vulnerability of the atrium to fibrillate inresponse to atrial pacing is independent of the presence of an AAVC.     

Radiofrequency Ablation of Concealed Left Free-Wall Accessory Pathways Without Coronary Sinus Catheterization:

Ablation of Concealed Accessory Pathways. Introduction: Feasibility of radiofrequency (RF) ablation using a two-catheter technique without coronary sinus catheterization was studied in 100 consecutive patients with a single concealed left free-wall accessory path-way.
Methods and Results: Tachycardia was induced by electrical stimulation in the right atrium/right ventricle, and the presence of a concealed left free-wall accessory pathway was suggested electrocardiographically (negative P wave in leads I and/or a VL during orthodromic tachycardia) or by earlier atrial activation in the pulmonary artery compared to the high right atrium. Mapping of the mitral annulus was performed during right ventricular pacing or orthodromic tachycardia, and RF energy was applied at the site with the earliest retrograde atrial activation. Ablation was considered effective if tachycardia could not be induced, and if VA dissociation or exclusive retrograde nodal conduction was observed. Ablation was initially successful in 98 of 100 patients. Mean number of radiofrequency pulses were 3.2 ± 2. Mean fluoroscopy time and total procedure time was 14 ± 9 and 107 ± 32 minutes, respectively. There were no complications related to the procedure. At a mean follow-up of 22 ± 13 months, two patients experienced tachycardia recurrence and required a second procedure, which was successful.
Conclusions: Our results suggest that RF catheter ablation of concealed left free-wall accessory pathways can be safely, effectively, and rapidly performed using a simplified two-catheter technique with no need for coronary sinus catheterization.     

射频消融右侧房室旁路治疗房室折返性心动过速

以射频电流消融6例预激综合征患者的右侧旁路。其中右前间隔旁路3条,右后间隔1条,右游离壁2条。平均放电21次,平均累积电能23000J。6条旁路均被阻断,无严重并发症。平均随访7个月,均未复发。     

Unusual Locations for Adenosine-Sensitive Accessory Atrioventricular Pathways with Decremental Conduction

Locations of Decremental Accessory Pathways. Introduction : Accessory AV pathways with decremental conduction are uncommon and, in particular, are thought not to occur at the anterior portion of the mitral annulus.
Methods and Results : This report describes successful catheter ablation in three patients with accessory AV pathways that were adenosine sensitive and showed decremental conduction properties. The pathways were located at the anteroseptal, anteroparaseptal, and anterolateral aspects of the mitral annulus.
Conclusion : Accessory pathways with decremental conduction do occur anywhere around the mitral annulus, even in the area of fibrous continuity between the aortic leaflet of the mitral valve and the aortic valve itself.     

Electrophysiologic Characteristics and Radiofrequency Catheter Ablation in Atrioventricular Node Reentrant Tachycardia with Second-Degree Atrioventricular Block

Second-Degree AV Block During AVNRT. Introduction : Detailed electrophysiologic study of AV nodal reentrant tachycardia (AVNRT) with 2:1 AV block has been limited.
Methods and Results : Six hundred nine consecutive patients with AVNRT underwent electrophysiologic study and radiofrequency catheter ablation of the slow pathway. Twenty-six patients with 2:1 AV block during AVNRT were designated as group I, und those without this particular finding were designated as group II. The major findings of the present study were: (1) group I patients had better anterograde and retrograde AV nodal function, shorter tachycardia cycle length (during tachycardia with 1:1 conduction) (307 ± 30 vs 360 ± 58 msec, P < 0.001), and higher incidence of transient bundle branch block during tachycardia (18/26 vs 43/609, P < 0.001) than group II patients: (2) 21 (80.8%) group I patients had alternans of AA intervals during AVNRT with 2:1 AV block. Longer AH intervals (264 ± 26 vs 253 ± 27 msec, P = 0.031) were associated with the blocked beats. However, similar HA intervals (51 ± 12 vs 50 ± 12 msec, P = 0.363) and similar HV intervals (53 ± 11 vs 52 ± 12, P = 0.834) were found in the blocked and conducted beats; (3) ventricular extrastimulation before or during the His-bundle refractory period bundle could convert 2:1 AV block to 1:1 AV conduction.
Conclusions : Fast reentrant circuit, rather than underlying impaired conduction of the distal AV node or infranodal area, might account for second-degree AV block during AVNRT. Slow pathway ablation is safe and effective in patients who have AVNRT with 2:1 AV block.     

Ebstein畸形与正常心脏结构合并右侧房室旁道射频消蚀的对比观察

为探讨心内结构异常合并房室旁道患者射频消蚀的难易程度，对射频消蚀８例先天性心脏病Ｅｂｓｔｅｉｎ畸形（Ⅰ组）与２０例合并右侧房室旁道心内结构正常者（Ⅱ组）进行观察。结果显示：两组心动过速的心室率、旁道的前传和逆传不应期均相近，差异无显著性；两组消蚀导管的选择与操作过程无不同之处，其总操作时间、Ｘ线投照时间和放电次数分别为：１１０±６３ｍｉｎＶＳ１０３±５５ｍｉｎ、４５±２１ｍｉｎＶＳ３９±１７ｍｉｎ、６±４次ＶＳ６±３次，Ｐ均＞０．０５。且两组病例均一次消蚀成功。结果说明Ｅｂｓｔｅｉｎ畸形合并房室旁道的射频消蚀同样较易成功。手术操作需轻柔，对合并右心功能不全者应避免心动过速的诱发；倒“Ｕ”形导管塑形，可加强导管的稳定性。     

经上腔静脉途径射频消融右侧前上和前间隔房室旁道

报道经上腔静脉途径射频消融右侧前上和前间隔房室旁道的体会。 13例右侧前上或前间隔单一房室旁道患者 ,常规下腔静脉途径消融未能成功 ,失败原因包括 :消融电极与心肌接触不良或难以固定于三尖瓣环上。改经上腔静脉途径成功消融阻断所有房室旁道。平均放电 1.8± 0 .7次 ,输出功率 33± 4W ,消融靶点电图振幅明显高于下腔静脉途径 (1.4± 0 .3mVvs 0 .6± 0 .4mV ,P <0 .0 5 )。术后随访 17± 9个月 ,无 1例复发。作者认为对经下腔静脉途径消融失败的右侧前上和前间隔房室旁道采用上腔静脉途径消融可获得成功。