射频电能消融术治疗房室结折返性心动过速的临床应用

应用射频电能房室连接区部分消融术治疗5例房室结折返性心动过速.术后5例之房室逆行传导均消失,4例房室结双径路不复存在,其中3例伴Ⅰ度房室结内传导阻滞,临床电生理复查5例之心动过速不能诱发.随访1.5～12.5月,所有患者均未再发心动过速,亦未服用任何抗心律失常药物.作者认为射频电能是改变房室传导较好的能源,具有比直流电安全、方便,损伤小,疗效高的特点.此外,本文对达到良好改变房室传导的射频消融部位,所用电能大小及释放时间等作了讨论.     

射频消融阻断房室旁路后室房逆传的特点

以射频电流阻断90例预激综合征患者的房室旁路.62例(68.9%)于旁路消融后呈室房分离,28例(31.1%)呈室房递减性传导.室房分离与患者年龄、性别及旁路传导特性无关,但左或右游离壁旁路阻断 后室房分离者多于递减传导者,而间隔旁路阻断后差别不显著.3例复发均为室房递减传导者.本研究提示,心房激动长期经旁路下传致房室结功能废用性退化可能为室房分离的原因,旁路阻断后室房递减传导者应仔细检测以除外潜在的旁路逆传.     

Nighttime Differential Autonomic Modulation of Sinus and Idioventricular Automaticity and of Atrioventricular Nodal Conduction

Background: Potential differential effects of the autonomous nervous system on sinus node and protected idioventricular automaticity and on atrioventricular nodal conduction have not been assessed in the same patients. Methods: The sinus cycle lengths, parasystolic cycle lengths, uncorrected QT intervals, and PR intervals were measured in control epochs and epochs of transient spontaneous maximal nighttime heart rate accelerations occurring between 1 and 4 AM. Noncontiguous epochs were selected to avoid potential accommodation-like, or memory effects that could occur at the moments of abrupt acceleration or decelerations of sinus rate. Results: The longest sinus cycle lengths coincided with the longest parasystolic cycle lengths and uncorrected QT intervals, whereas the shortest sinus cycle lengths coexisted with the shortest parasystolic cycle lengths and the shortest QT intervals. In contrast, the PR intervals did not show a uniform behavior during the episodes of transient heart rate accelerations since they could increase, decrease, or remain the same. Conclusion: The different behavior of cycle lengths and PR intervals during nighttime heart rate increases, suggests that the autonomic modulation of the sinus node, idioventricular focus, and the AV node can be independent from each other. A.N.E. 1999;4(4):385–390     

Alternation of Atrioventricular Nodal Conduction Time During Atrioventricular Reentrant Tachycardia:

AV Nodal Conduction Time Alternation. Introduction: Alternation of atrial cycle length and AV nodal conduction time (NCT) is often observed during AV reentrant tachycardia. Both AV nodal dual pathway and rate-dependent function have been postulated to be involved in this phenomenon. This study was designed to determine the respective role of these two mechanisms in the alternation observed in an in vitro model of orthodromic AV reentrant tachycardia. Methods and Results: The tachycardia was produced by detecting each His-bundle activation and stimulating the atrium after a retrograde delay, thereby simulating retrograde pathway conduction, in six isolated rabbit heart preparations. After a 5-minute stabilization period at a fast rate, the retrograde delay was decremented by 2 msec every minute until nodal blocks occurred. We observed a sequential alternation of the cycle length and NCT in four preparations in the short retrograde delay range. The magnitude of the alternation gradually increased as the retrograde delay was decreased and reached 4.6 ± 0.5 msec during 1:1 conduction. The alternation increased further just prior to termination of the tachycardia by an AV nodal block. None of the preparations showed discontinuous AV nodal recovery curves. Moreover, an electrode positioned over the endocardial surface of the node showed that the alternation developed distally to the nodal inputs, which are believed to constitute a major component of dual pathways. A mathematical model predicted the alternation from known characteristics of rate-dependent nodal functional properties. Conclusions: NCT and cycle length alternation can arise during orthodromic AV reentrant tachycardia when the retrograde delay is sufficiently short. The characteristics of the alternation, presence of continuous recovery curves, intranodal location of the alternation, and mathematical modeling suggest that the alternation is predictahle from the known functional properties of the AV node without postulating dual pathway physiology.     

房室结双径路传导的心电图表现

目的探讨房室结双径路传导引起的心电图表现及形成机制。方法回顾性分析19例患者的常规心电图及动态心电图中出现的房室结双径路传导现象。结果观察到6种房室结双径路传导现象：①房性期前收缩或心房颤动诱发慢快型AVNRT,②AVNRT伴2：1房室传导阻滞或功能性束支传导阻滞时不影响心动过速周长,③室性期前收缩诱发慢快型及快慢型AVNRT,④房性期前收缩重整慢快型AVNRT,⑤两条房室结慢径路交替顺传引起的慢快型AVNRT,⑥房室结双径路同步不等速传导引起的1：2房室传导及折返。结论认识这些心电图现象并了解其形成机制,有助于体表心电图诊断房室结双径路传导。     

经导管射频消融改良房室结治疗房室结折返性心动过速

报道24例病人经射频消融(RFCA)慢径改良房室结治疗房室结折返性心动过速(AVNRT)的研究结果。RFCA后24例病人均不再诱发AVNRT(100％),其中23例慢径传导消失(95.8％),1例慢径传导明显减慢(4.2％)。认为RFCA改良慢径对房室和室房传导没有明显影响,其消融成功的可能预测指标为:X线影象消融电极位于房室结后下部、消融电极图A/V<0.4,放电出现交界性早搏或并行性交界性心律。     

Gender Differences in the Clinical Characteristics and Atrioventricular Nodal Conduction Properties in Patients With Atrioventricular Nodal Reentrant Tachycardia

Gender Differences in Patients With AVNRT. Introduction: The detailed electrophysiological characteristics of the gender differences associated with atrioventricular nodal reentrant tachycardia (AVNRT) have not been clarified. This study investigated the gender‐related electrophysiological differences in a large series of patients undergoing radiofrequency catheter ablation. Methods and Results: A total of 2,088 consecutive AVNRT patients (men/women 869/1,219) who underwent catheter ablation were enrolled in this study. We evaluated the gender differences in their electrophysiological characteristics. Women had a significantly younger age of onset, higher incidence of multiple jumps, shorter AH interval, atrial effective refractory period (ERP), anterograde fast pathway ERP, anterograde slow pathway ERP, and retrograde slow pathway ERP, and longer ventricular ERP than men. The incidence of baseline ventriculoatrial dissociation was lower in women than in men. Women needed less isoproterenol/atropine to induce AVNRT. No gender differences in the radiation exposure time, procedure time, complication rate, acute success rate, or second procedure rate were noted. Both typical and atypical AVNRT were more predominant in women. In the patients with atypical AVNRT, there was no significant gender difference in incidence of baseline ventriculoatrial dissociation; however, the retrograde slow pathway ERP was significantly shorter in women than in men. Women of premenopausal age (≤50 years old) had a significantly higher incidence of anterograde multiple jumps and a retrograde jump phenomenon, and a shorter anterograde slow pathway ERP and retrograde slow pathway ERP than those of women over 50 years old. Conclusion: Gender differences in the anterograde and retrograde AV nodal electrophysiology were noted in the patients with AVNRT. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1114‐1119)     

选择性消融逆传快径治疗典型房室结折返性心动过速

设计一种新的射频消融方法（选择性消融逆传快径）对25例反复发作的典型房室结折返性心动过速（AVN－RT）进行消融治疗。经股静脉插入1～2很大头电极至Koch氏三角区,于旁His束心室起搏下寻找还传A’最早的靶点,靶点图上不能有或仅有极小H波,大头电极用力压向靶点出现：①VA分离或H’A’间期延长,说明逆传快径已被机械刺激所阻断,立即放电15～25W,持续30～90S;②AH间期延长,说明前传快径已被机械刺激所阻断,移开大头电极待AH间期恢复正常,再重新标测;③反复数次操作,大头电极的机械刺激仍不能阻断逆传快径,则选择逆传A’最早的靶点试放电30S,出现VA分离或H’A’间期延长,则放电至60～90s,否则重新标测靶点。消融终点为VA分离或H’A’间或延长,用异丙肾上腺素仍不能诱发典型和非典型AVNRT。25例均一次消融成功,逆传快径被阻断、前传慢径均保留;23例VA分离、2例仅有H’A’间期延长;6例前传快径阻断;4例病人术中大头电极的机械刺激阻断了逆传快径。1倒成功靶点位于His束电极后上方,24例位于His束电极与冠状窦电极之间的区域。结论：在仔细精确的电生理标测下可实现选择性消融逆传快径,保留前传快慢径。此方法安全有效。     

房室结双径路传导在动态心电图上的不同表现

目的 探讨房室结双径路传导引起的心电图表现及其形成机制.方法 对27例患者动态心电图中出现的房室结双径路现象进行回顾性分析.结果 房室结双径路传导表现为9种心电图特征:顺向房室传导呈跳跃现象,无心房回波,呈不典型文氏现象及反文氏现象;顺向房室传导呈跳跃现象,伴心房回波,呈不典型文氏现象;顺向房室传导呈跳跃现象,隐匿性逆传快径路连续发生蝉联现象,貌似阵发性室上性心动过速;房性或室性期前收缩诱发慢-快型或快-慢型房室结折返性心动过速;房室结下部共同通道阻滞不中止折返环;窦性P波分别经快、慢径路传导致心室双反应(即房室结双径路的1∶2传导现象);经慢径路或慢快径路交替顺传、旁道逆传的房室折返性心动过速.结论 动态心电图上P-R间期呈跳跃现象提示存在房室结双径路.     

冷冻消融在治疗房室结折返性心动过速中的疗效

目的观察经导管冷冻消融房室结慢径治疗房室结折返性心动过速(AVNRT)的疗效。方法对本院13例AVNRT患者行冷冻消融房室结慢径路治疗,先用-30℃行冷冻标测,确定有效靶点且无快径损伤后,立即行-75℃冷冻消融,消融4~8分钟,消融过程中密切观察房室结传导功能,一旦发现有房室结损伤,立即终止消融,改换靶点。结果13例均获成功,随访1~9个月无复发;在冷冻标测及冷冻消融时导管顶端与靶点无位移现象;冷冻标测与冷冻消融过程中无结性早搏或结性心律出现;2例在冷冻标测和冷冻消融过程中出现一过性房室阻滞,立即停止冷冻复温后,即刻传导恢复。无其它并发症发生。结论经导管冷冻消融是治疗AVNRT的有效方法,在一定温度时间内的组织损伤是可逆的,能够最大程度地减少永久性房室阻滞的风险,较传统射频消融术治疗AVNRT有较高的安全性。     

Radiofrequency Modification for Inducible and Suspected Pediatric Atrioventricular Nodal Reentry Tachycardia

Introduction: AV Node Reentry Tachycardia (AVNRT) is the second most common supraventricular tachycardia (SVT) undergoing pediatric radiofrequency ablation behind accessory pathway reentry tachycardias. AVNRT can be difficult to induce during electrophysiology study (EPS) and dual atrioventricular nodal (AVN) pathways physiology may not be demonstrated in young patients.Purpose: This report is the largest single center long term pediatric experience of radiofrequency modification of slow AVN input fibers for inducible or suspected (non-inducible) AVNRT.Results: One hundred thirty-two patients underwent slow input AVN modification from 1993 to 2002. The mean patient age was 13.7 years (4–20 yrs) with 62M/70F. Outpatient tachycardia was documented by ambulatory monitoring in all patients. AVNRT was induced in 98/132 patients during EPS (group A) with mean SVT cycle length of 324 msec (230–570 msec). Initial AVN modification (group A) was successful in 97/98 patients (99%). During 34/132 EPS, AVNRT was non-inducible; dual AVN physiology was present in 19/34 (group B), and 15/34 did not show evidence for dual AVN physiology (group C). These 34 patients underwent empiric AVN modification following discussion with patients’ families. Freedom of recurrence from SVT at 1 year was 96% for group A (94/98), 89% (17/19) for group B and 93% (14/15) for group C. 1 major and 6 minor complications occurred.Conclusions: AVN modification for AVNRT can be performed safely and effectively in pediatric patients with good long-term results. Empiric slow pathway AVN modification for non-inducible SVT results in a high rate of freedom from recurrence of tachycardia.     

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。     

Radiofrequency Catheter Ablation of Atrioventricular Nodal Reentrant Tachycardia after Orthotopic Heart Transplantation

Patients with orthotopic heart transplantation may develop a variety of arrhythmias. Successful radiofrequency catheter ablation for tachyarrhythmias from manifest and concealed accessory bypass tracts in transplant patients has been previously reported. We present a patient with orthotopic heart transplantation who developed typical atrioventricular nodal tachycardia, which was successfully treated by radiofrequency catheter ablation.     

射频能量测试交界性心律消融房室结折返性心动过速

探讨能量测试法在房室结折返性心动过速 (AVNRT)慢径标测与消融中的作用。将 90例AVNRT患者分成三组 (每组 30例 ) ,分别采用能量测试法、下位法和后位法进行慢径标测与射频消融。能量测试法是在Koch三角区逐步以小剂量多次试验放电标测 ,以出现加速性交界性心律为慢径传导部位 ;从 2 0W开始消融并增至 30W ,持续 12 0s ,以出现加速性交界性心律且逐渐转变为窦性心律为消融有效。能量测试法所需手术标测时间、X线曝光时间和消融能量明显少于后位法 (12 1± 43vs 183± 6 7min ,5 8± 2 1vs 93± 34min ,70 0 0± 470vs 12 0 0 0± 75 0J,P≤ 0 .0 5 ) ,而发生短暂性房室阻滞和交界性心动过速则均较下位法明显减少。慢径消融有效时几乎 10 0 %出现加速性交界性心律 ;慢径传导呈多部位分布。结论 :能量测试法运用于AVNRT慢径标测及消融中 ,能较敏感地揭示慢径传导部位和消融有效的靶点 ,为AVNRT慢径标测消融的有效方法。     

射频消融治疗房室结折返性心动过速对心率变异性的影响

对１０例房室结折返性心动过速患者采用频域、时域法分析射频消融前后心率变异，旨在了解射频消融后自主神经系统对窦房结的支配有否改变。结果显示心率变异的高频段（ＨＦＰ）、低频段（ＬＦＰ）成分较射频前有所减低，ＬＦＰ／ＨＦＰ之比（２．２０±１．３１ＶＳ５．１０±３．３２）明显增高（Ｐ＜０．０１）．提示射频消融后迷走神经功能相对减低，对窦房结的支配减弱。提出消融快径不但易并发ＩＩＩ度房室传导阻滞，而且易并发窦性心动过速。消融慢径则可防止窦性心动过速的发生。     

异丙肾上腺素对射频消融房室结折返性心动过速疗效评价的意义

对消融房室结慢径的７２例房室结折返性心动过速（ＡＶＮＲＴ）病人进行观察分析，以了解异丙肾上腺素在ＡＶＮＲＴ射频消融中的临床价值。消融前电生理检查时有２７．８％（２０／７２）的病人未能诱发ＡＶＮＲＴ，静脉滴注异丙肾上腺素后，８５．０％（１７／２０）则能诱发；消融后４７．９％（３４／７２）用异丙肾上腺素评价，其中８例既有房室结跳跃现象又有心房回波的病人５０．０％（４／８）诱发出ＡＶＮＲＴ而重新消融。随访８．５±４．３个月，成功消融的７１例中，３４例经异丙肾上腺素评价者无一例复发，３７例未用异丙肾上腺素评价者２例复发。提示静脉滴注异丙肾上腺素可提高ＡＶＮＲＴ的诱发率；消融后房室结慢径前传功能存在时，无论有无心房回波均应用异丙肾上腺素评价，以确定消融终点和降低复发率。     

Entrainment Mapping in Patients With Sustained Atrioventricular Nodal Reentrant Tachycardia: Insights Into the Sites of Conduction Slowing in the Slow Atrioventricular Nodal Pathway

The inferoposterior region of the triangle of Koch is hypothesized to be the location of the atrial insertion of the slow atrioventricular (AV) nodal pathway. However, the actual site of conduction slowing in the slow AV nodal pathway is unknown. Entrainment mapping during AV nodal reentry can localize the reentrant pathway as follows: the AH interval measured from the mapping catheter = A′H (where A′ is the exit site of the reentrant circuit) minus A′A (the conduction time from A′ to the site of mapping); the SH interval during entrainment = SA′ (the conduction time from stimulus into the reentry circuit) plus A′H. Thus, in all cases, the SH interval should be greater than or equal to the AH interval, and the ΔAH-SH should increase as distance and conduction time (SA′ and A′A) from the reentry circuit increases. Fourteen patients with typical AV nodal reentry (cycle length 346 ± 62 ms) and 1 with fast-slow (cycle length 430 ms) underwent activation and entrainment mapping from 8 to 12 sites in the triangle of Koch and coronary sinus. Pacing was performed at 2 to 3 mA above threshold, at a cycle length 10 ms shorter than tachycardia. A mapping site was defined as being in close proximity to the circuit if the ΔAH-SH was within 120% of the shortest 20th percentile ΔAH-SH value from all measured sites. In the 14 typical cases, 45 of 83 sites (54%) in the anatomic slow pathway region fulfilled criteria for close proximity to the reentry circuit compared with 13 of 50 sites (26%) outside of this region (p = 0.005). For these patients, the shortest SH interval measured from any entrainment site was 294 ± 58 ms (89 ± 10% of tachycardia cycle length, range 70% to 119%), indicating that the site of slow conduction in the slow pathway during AV nodal reentrant tachycardia was distal to all mapped sites. Thus, during typical AV nodal reentry, the “slow” pathway does not conduct slowly, and its insertion is located at or within the inferoposterior or midseptal regions in most cases.     

冷冻消融与射频消融治疗房室结折返性心动过速的比较

目的:比较经导管冷冻消融与射频消融治疗房室结折返性心动过速(AVNRT)的临床效果及安全性.方法:根据治疗方法将83例经电生理检查确诊为AVNRT的患者分为冷冻消融组(冷冻组,n=41)和射频消融组(射频组,n=42).比较两组的临床特征、成功率、手术时间及复发率等.结果:两组一般临床特点无明显差异.冷冻组的手术时间明显比射频组长[(119.14±40.16)min vs (85.86±28.24)min,P=0.001],差异有统计学意义.冷冻组和射频组消融即刻成功率相似(97.6% vs 100.0%,P=0.309),差异无统计学意义.冷冻组较射频组一过性房室传导阻滞(AVB)的发生率稍高(15.0% vs 11.9%,P=0.681),但差异无统计学意义,且两组均无完全AVB发生.两组患者在平均(11.6±5.5)个月的随访期内均无AVNRT复发.结论:冷冻消融治疗AVNRT与射频消融一样有效且安全.冷冻消融可作为AVNRT的常规消融方式之一.     

房室结改良术终点与复发率的关系

为探讨房室结改良术成功后不同电生理终点对复发率的影响，观察了８０例房室结改良术患者复发情况。其中双径现象消失（Ａ组）５１例；仍有双径现象，但无心房回波（Ｂ组）２１例；有双径现象，且有１个心房回波（Ｃ组）８例。消融成功后观察３０ｍｉｎ，急性复发４例（５．８％）；术后随访１４．７±５．６（６～３９）个月慢性复发３例（３．８％），共复发７例（８．８％）。７例中，Ａ组与Ｂ组各２例、Ｃ组３例，复发率分别为３．９％、９．５％、３７．５％。其中Ａ组与Ｃ组比较复发率差异非常显著（Ｐ＜０．０１），其余差异无显著性（Ｐ＞０．０５）。此结果表明，选用三种终点中的任何一种，术后大多数患者都未复发。而为了降低复发率，除了消融成功后至少应观察３０ｍｉｎ以消除急性复发外，在技术成熟的单位，可力争以双径现象消失为改良术终点。     

Atrioventricular Conduction After Transcatheter Aortic Valve Implantation and Surgical Aortic Valve Replacement

AV Conduction After TAVI and SAVR . Introduction: Atrioventricular conduction abnormalities (AVCA) may complicate transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR). The aim of this study was to prospectively evaluate AVCA after TAVI and SAVR. Methods and Results: Among 50 patients undergoing TAVI and 25 patients undergoing SAVR a continuous 7‐day Holter electrocardiogram (ECG) was recorded after the procedure. ECGs during TAVI and 12‐lead ECGs before and 1 and 7 days after TAVI and SAVR were analyzed. At baseline, TAVI patients were older (mean 82.1 vs 75.4, P < 0.001), had a longer PR interval (median 200 milliseconds vs 175 milliseconds, P = 0.004) and broader QRS width (median 100 milliseconds vs 80 milliseconds, P = 0.007) than SAVR patients. New AVCA were observed among 29 TAVI patients (58%), mostly new left bundle branch block (76%). Predilatation induced new AVCA in 14 TAVI patients (28%). New AVCA resolved within 24 hours in 15 TAVI patients (30%), and persisted in 14 TAVI (28%) and 3 SAVR patients (12%, P = 0.12). Among patients with persistent QRS width <120 milliseconds during the first 24 hours after TAVI, QRS width remained stable during the remainder of the observation period. During Holter monitoring complete AV block was observed in 4 TAVI patients (8%) and 3 SAVR patients (12%; P = 0.68). Conclusions: Almost half of AVCA during TAVI are induced by predilatation, but half of them resolve within 24 hours. Persistent AVCA are more frequently observed after TAVI than SAVR. If QRS width is below 120 milliseconds the first day after TAVI, the risk of late AVCA seems low. (J Cardiovasc Electrophysiol, Vol. 23 pp. 1115‐1122, October 2012)