右房后壁双电位标测对判断房性心动过速起源点的参考价值

目的探讨右房后壁双电位标测对判断房性心动过速(简称房速)是否起源于左房的价值。方法选取19例成功行射频消融治疗的房速患者,房速起源点位于左房12例,位于右房7例,所有病例均在右房后壁记录到双电位。结果左房房速时,双电位的第一个成分振幅均明显低于第二个成分,且窦性心律时,同一部位记录的双电位顺序发生逆转,而右房房速时,第一个成分振幅均明显高于第二个成分,窦性心律时两电位的顺序不改变。结论通过右房后壁双电位标测,能快速而可靠地判断房速是否起源于左房。     

Simple and accurate catheter mapping technique to predict atrial fibrillation foci in the pulmonary veins or posterior right atrium.

OBJECTIVES: The purpose of this study was to investigate the efficacy of a novel catheter mapping technique for predicting atrial fibrillation (AF) foci. BACKGROUND: Most AF originates from pulmonary veins (PVs), but some originate from the right atrium. METHODS: We developed an algorithm by correlating the cardiac recordings obtained from multielectrode catheters placed in the posterior right atrium (RA) and esophagus during pacing from the PVs and superior vena cava (SVC) or crista terminalis (CT) in 10 AF patients. We tested the algorithm's accuracy prospectively in 46 AF patients. RESULTS: During pacing from the left PVs, the esophageal potentials preceded all other potentials. During pacing from both the right PVs and SVC-CT, the first component (FP) of the double potential (DP) recorded in the posterior RA preceded all other potentials. The amplitude of the FP was higher than that of the second DP component during pacing from the SVC-CT, whereas the reverse occurred from the right PVs. The activation sequence of the FPs and esophageal potentials was from superior to inferior during pacing from the superior PVs, whereas the reverse occurred from the inferior PVs. The accuracy of predicting 34 foci in the right PVs, 28 foci in left PVs, and 6 foci in SVC-CT was 100% for all, respectively. The accuracy of discriminating foci in the superior PVs from those in the inferior PVs was 97% in the right PVs and 96% in the left PVs. CONCLUSIONS: The technique using mapping catheters placed in the posterior RA and esophagus is feasible and effective for mapping and ablating AF.     

Atrial tachycardia arising from the right atrial inferoseptum masquerading as common atrial flutter.

Radiofrequency catheter ablation was performed in 2 patients with atrial tachycardia (AT). In both cases the AT originated from the inferoseptal portion of the right atrium, and the cycle length was 210 ms. The surface ECG demonstrated common counterclockwise atrial flutter, probably caused by functional block in the clockwise direction at the cavo-tricuspid isthmus and posterior right atrium with rapid activation of the origin. Although rare (2%), AT originating from the inferoseptum of the right atrium should be considered when the surface ECG exhibits common atrial flutter.     

三维标测指导下射频导管消融右心耳起源的局灶性房性心动过速

目的 报道应用三维标测指导射频导管消融起源于右心耳的局灶性房性心动过速(房速),并初步探讨其临床及心电学特征.方法 共6例患者(男性4例,女性2例,年龄(43±19)岁]临床诊断为窄QRS心动过速,其中3例曾行常规射频消融失败,4例左心房内径明显扩大.经电生理检查证实为房速.术中行EnSite-NavX激动标测或者Carto电解剖标测以明确局灶性房速并指出最早激动大致范围.在局部做精细标测找到心房最早激动处,于心动过速时应用盐水灌注导管放电消融,能量30～40 W,温度43℃.即刻成功指标为心动过速终止并不再被诱发.结果 6例心动过速平均心动周期为(343±53)ms.三维激动标测结果显示房速呈右心耳部位点状扩布,并且整个右心房激动时间占心动周期的27%±8%.成功消融靶点局部A波较体表心电图P波提前(52±13)ms.消融后行右心房心耳造影确认消融导管位置.6例右心耳房速均成功消融且未有并发症发生.随访3个月其中1例复发心动过速,经再次标测证实为三尖瓣前侧部局灶性房速并且成功消融.左心房扩大者心房内径较术前显著缩小[(41±6)mm对(36±6)mm,P＜0.05].结论 局灶性房速可起源于右心耳并可以成功消融.三维标测有助于靶点定位及消融成功.     

Swallowing-induced multifocal atrial tachycardia originating from right pulmonary veins

A 64-year-old woman experienced reproducible palpitation caused by irregular atrial tachycardia (AT) while swallowing. This tachycardia was resistant to multiple antiarrhythmic drugs and β-blockers. Catheter mapping revealed right pulmonary vein (PV) firings with different activation sequences, thereby producing multifocal AT. Extensive encircling isolation of ipsilateral right PVs abolished the multifocal AT. Although isolated right PVs were captured by pacing, dissociated PV firings were not induced by swallowing after radiofrequency catheter ablation.     

Nonpharmacological treatment of atrial tachycardia.

The authors analyse the efficacy and safety of catheter ablation and atrial pacing for the treatment of atrial tachycardia. Radiofrequency catheter ablation was selected whenever the arrhythmogenic focus was located on the free-wall or in the meso-septal area of the right atrium. In opposition, overdrive atrial pacing was chosen for tachycardias originating near the sinus complex or in the left atrium. Both therapies were safe, but had a low efficacy in converting the tachycardia into sinus rhythm. However, catheter ablation allows an irreversible destruction of small septally located foci. Thus, both the anatomical and the electrophysiological characteristics of the foci can be important factors in the selection of the most appropriate nonpharmacologic therapy.     

心房颤动环肺静脉隔离术后复发左房房性心动过速的特点及消融治疗

目的探讨心房颤动(简称房颤)环肺静脉隔离术后(CPVI)复发左房房性心动过速(简称房速)再次射频消融中,房速机制的鉴别和消融策略的选择。方法18例房颤经CPVI术后复发房速患者,其中男16例,女2例,年龄61.4±6.5(50～70)岁。在持续稳定的自发/诱发房速时在Carto指导下行激动顺序标测,经电生理检测,明确房速机制并选择相应消融方式:对于局灶性房速,重新阻断原消融径线上裂隙或消融最早激动区;对于折返性房速,明确关键峡部,行线性消融,如果有肺静脉电位亦行对裂隙的消融。结果共有13例肺静脉恢复电活动(72.7%)。局灶性房速6例,折返性房速12例(包括11例左房大折返和1例肺静脉-左房折返)。相应方式消融后房速均转为窦性心律,且肺静脉电位消失。结论房颤CPVI术后复发的左房房速与肺静脉电位的恢复密切相关;与消融线和裂隙形成的折返有关。     

Identification of left atrial origin of ectopic tachycardia during right atrial mapping: analysis of double potentials at the posteromedial right atrium

INTRODUCTION: The high posteromedial right atrium is adjacent to the left atrium near the right superior pulmonary vein. We hypothesized that analysis of electrograms at this site could distinguish left from right atrial tachycardia. METHODS AND RESULTS: Atrial mapping was performed in 16 patients with left atrial origin ectopic tachycardia (11 patients with right superior pulmonary vein origin and 5 patients with other left atrial tachycardias). During left atrial tachycardia, earliest right atrial activation was recorded at the high posterior right atrium in 14 of 16 patients. At all of these 14 early sites, double potentials were recorded during tachycardia. The first potential was a far-field signal from left atrium as indicated by the following: (1) during sinus beats, the timing of the two potentials reversed such that the left atrial one was late; (2) ablation at the right atrial site did not decrease the amplitude of the first potential, but did decrease the amplitude of the second potential; and (3) the timing of activation at the adjacent left atrium agreed with that of the first potential. In the 11 right superior pulmonary vein tachycardias, the first potential was markedly earlier than the p wave onset, but in left atrial tachycardias with other origins it was later. In a control group of six patients with pacing to simulate right atrial tachycardia, double potentials were recorded in the posterior right atrium, but the timing of components did not reverse during sinus rhythm. CONCLUSION: For some left atrial ectopic tachycardias, particularly those originating from the right superior pulmonary vein, recognition of left versus right atrial origin can be accomplished during right atrial mapping by analysis of double potentials in the posteromedial right atrium.     

心房不同部位拖带法鉴别不典型房室结折返性心动过速和房性心动过速

目的报道一种鉴别不典型房室结折返性心动过速(AVNRT)和起源点邻近Kock三角的房性心动过速(AT)的新方法。方法 22例室上性心动过速患者,在心房不同部位(右房心耳部、冠状静脉窦近端、远端)起搏拖带心动过速,测定起搏后VA间期(最后一个起搏脉冲前传夺获的心室电图到起搏终止后第一心搏的最早心房电图的距离)。计算各部位起搏后VA间期的差别并取差别绝对数的最大值定义为ΔVA间期。结果 13例AVNRT起搏后ΔVA间期5.8±3.6(0～14)ms,9例AT起搏后ΔVA间期62.8±24.2(21～98)ms。ΔVA间期在所有AVNRT均<15 ms,在所有AT均>15 ms,因此起搏后ΔVA间期>15 ms用于诊断AT的灵敏度和特异度均为100%。结论心房不同部位起搏拖带法可用于准确鉴别不典型AVNRT和起源点邻近Kock三角的AT。     

P波形态对预测局灶性房性心动过速部位的研究

目的　探讨通过局灶性房性心动过速 (简称房速 )发作时的P波形态初步诊断左房或右房房速。方法　入选 33例房速病人 ,经成功的射频消融术治疗证实其中 10例起源于左房 ,2 3例起源于右房。回顾分析这些病例房速发作时的体表 12导联心电图 ,研究各导联P波形态与左房房速的相关性。结果　I导联和aVL导联P波负向预测左房房速的特异性分别达到了 10 0 %和 95 % ,但敏感性分别仅有 30 %和 5 0 % ;而V1导联P波正向的特异性和敏感性分别为 87%和 80 %。结论　通过房速发作时的P波形态分析 ,可初步预测房速的起源部位 ,为术前准备及选择恰当的手术方式提供参考     

心脏病外科术后右房房性心动过速的标测及射频消融

目的总结分析心脏病外科术后右房起源房性心动过速(简称房速)的标测及射频消融结果。方法共入选27例心脏外科术后持续性右房房速患者,在心动过速状态下采用三维电解剖标测系统建立右房激动标测图和电压图,标示出疤痕区及双电位区,并揭示心动过速的机制。根据标测结果选择心动过速的关键峡部或起源点进行消融。结果心动过速机制分为以下几种类型:单环折返包括右房峡部依赖性心房扑动(15例)和切口折返性房速(5例);双环折返性房速(3例);两种以上机制(包括局灶性)的复杂房速(4例)。术中即时手术成功率100%。随访过程中5例复发房速,3例再次消融成功。结论心脏外科术后右房房速多数与外科手术切口疤痕相关,在三维电解剖标测系统指导下射频消融治疗效果满意。     

Exit block of focal repetitive activity in the superior vena cava masquerading as a high right atrial tachycardia

An unusual case of atrial tachycardia (AT) originating from the superior vena cava (SVC) is reported. A 34-year-old man without structural heart disease underwent catheter ablation for drug-resistant AT. During the tachycardia, low-amplitude spiky electrograms with a cycle length of 120 to 175 msec were recorded in the SVC and exhibited 2:1 exit block to the atria, masquerading as the atrial activation observed with high right AT. These spiky electrograms also were observed during sinus rhythm, but they appeared immediately after the local atrial electrograms. The spikes were traced to a point 3 cm above the junction of the right atrium. Radiofrequency ablation at the site of the earliest appearance of the spike in the SVC successfully eliminated the tachycardia. During the following 15 months, no clinically significant atrial arrhythmias, including atrial fibrillation, occurred. This report indicates that careful mapping, including inside the SVC, will be a requisite in patients with high right atrial tachyarrhythmias.     

Adenosine-induced atrial tachycardia and multiple foci initiating atrial fibrillation eliminated by catheter ablation using a non-contact mapping system

A 47-year-old male with both atrial tachycardia and atrial fibrillation underwent catheter ablation. During the procedure, rapid administration of adenosine triphosphate induced atrial tachycardia. A non-contact mapping system revealed a focal atrial tachycardia originating from the lateral right atrium, which was successfully ablated. Following the ablation of tachycardia, atrial fibrillation was induced by the injection of adenosine along with multiple extra pulmonary vein foci, which were eliminated by the application of radiofrequency under the guidance of a non-contact mapping system.     

Radiofrequency catheter ablation of atrial tachycardia

Background: Atrial tachycardia is a relatively uncommon arrhythmia which usually responds poorly to antiarrhythmic drug therapy. Transcatheter radiofrequency (RF) ablation is a new therapeutic modality for patients with atrial tachycardia. Aim: This study analyses our early experience with the treatment of atrial tachycardia by this technique. Methods: Thirteen consecutive patients (age 13–63 years) with 15 drug-refractory atrial tachycardia foci were treated with RF catheter ablation. Atrial tachycardia was mapped by seeking the earliest atrial activation in the right atrium in eight patients and in the left atrium in five. Results: Tachycardias were abolished in nine (69%) patients, including two sinoatrial re-entrant tachycardias and seven automatic atrial tachycardias, after 9±10 (range, one to 28) pulses of RF current. Six of these ablated atrial tachycardia foci were right sided and three were on the left. One patient had three separate right atrial tachycardia foci; one was eliminated. Tachycardia recurred after two weeks in one patient with apparently successful ablation of sinoatrial re-entrant tachycardia. One patient with successful ablation of a right atrial tachycardia developed cardiac tamponade requiring surgical intervention. Conclusion: This study demonstrates that atrial tachycardia arising from diverse sites can be eliminated by RF catheter ablation.     

Electrophysiologic and electrocardiographic characteristics and radiofrequency catheter ablation of focal atrial tachycardia originating from the left atrial appendage.

BACKGROUND: The left atrial appendage (LAA) is one of the major sources of focal atrial tachycardias (ATs). OBJECTIVE: The purpose of this study was to investigate the detailed electrophysiologic characteristics and catheter ablation of focal ATs originating from the LAA. METHODS: The study population consisted of 47 consecutive patients with 50 focal ATs originating from the left atrium (LA): LAA in 13, left pulmonary veins (PVs) in 14, right PVs in 12, and mitral annulus in 11. Programmed electrical stimulation and pharmacologic testing were performed to examine the mechanism of LAA AT. Left atriography was performed prior to radiofrequency ablation to identify the focus in the LAA. RESULTS: The mechanism of LAA AT was automaticity in 11 and triggered activity in 2. The 13 LAA foci were located mainly at the LAA base: 11 on the medial side and 2 on the lateral side. Atrial activation sequences within the distal coronary sinus were helpful in differentiating these LAA foci. The criterion of a negative P wave in leads I and aVL indicating an LAA AT focus was associated with sensitivity of 92.3%, specificity 97.3%, positive predictive value 92.3%, and negative predictive value 97.3%. No complications occurred in any of the 13 patients. All 13 patients were free of atrial arrhythmias without any antiarrhythmic drugs during follow-up of 8 +/- 3 years. CONCLUSION: LAA ATs have typical electrophysiologic and electrocardiographic characteristics that are helpful in guiding radiofrequency catheter ablation.     

应用CARTO系统射频消融儿童快速右房房性心律失常的初步体会

目的　初步总结应用CARTO系统指导射频消融儿童快速右房房性心律失常的经验。方法　右房房速（AT）3例,典型房扑（AF）l例,心动周期(277±31)ms,在心动过速时应用CARTO系统标测右房,重建三维电解剖图并指导射频消融靶点;房扑消融后分别在低位右房和冠状窦以500ms起搏作电解剖图,判断完全双向传导阻滞。结果　2例为局灶性房速,起源点分别在希氏束旁（Koch三角）和高位右旁;1例为右房壁疤痕介导的折返性房性心动过速(IART)。4例成功消融,放电次数(10.6±5.5)次,透视时间(18±9)min,术程(110±38)min。结论　(1)CARTO系统容易寻找最佳靶点;(2)房扑消融后在低位右房和冠状窦起搏作电解剖图,判断完全双向传导阻滞,大幅度减小X线透视时间,提高成功率,降低复发率。     

How to map and ablate atrial scar macroreentrant tachycardia of the right atrium.

A special form of macroreentrant atrial tachycardia (MRAT), due to reentrant activation around surgical scars, can occur in patients after cardiac surgery. Scar MRAT occurs usually after correction of congenital defects, such as atrial or ventricular septal defects, and especially after Mustard, Senning or Fontan procedures, but it can occur also after myxoma, valvular or coronary bypass surgery. The simplest form of scar MRAT is reentry around a lateral right atrial surgical scar. A basic mapping array with multiple simultaneous recordings from the anterior and septal right atrium is very useful to make the electrophysiological diagnosis. A line of double electrograms can be mapped in the centre of the circuit and a fragmented electrogram usually marks the pivoting point between the inferior end of the scar and the inferior vena cava (IVC). Extension of the scar toward the closest fixed obstacle, usually the IVC, by means of radiofrequency ablation, can interrupt the tachycardia and make it non-inducible. Typical atrial flutter usually coexists with scar MRAT and flutter isthmus ablation is probably indicated in all cases. In patients having undergone baffle atrial surgery it can be impossible to map the whole circuit and entrainment-mapping is helpful to localize critical isthmuses in the circuit. After the Fontan operation the right atrium can be severely dilated and scarred, and multiple, complex reentry circuits can be found. Left atrial MRAT based on large areas of scar has been described, but there is still too little experience with these to propose general rules for diagnosis and management.     

儿童房性心动过速的电生理标测和射频导管消融

目的报道儿童房性心动过速（房速）的电生理标测及射频导管消融的疗效。方法43例患儿（男性23例,女性20例）,年龄2～14（7．1±3．1）岁,其中33例为无休止房速,17例伴有明显的左心室扩大及慢性心力衰竭。所有患儿均进行电生理标测,在最早激动点进行导管射频消融。结果39例自发或诱发房速,局灶起源36例（右心房26例,左心房10例）,先天性心脏病后大折返房速3例。35例（89．7％）患儿消融术即刻成功,消融术中及术后无严重并发症发生。平均随访（25．2＋-13．5）个月,34例（87．2％）患儿不服药亦无房速发作,其余均获得明显改善。14例左心室重度扩大及射血分数减低患儿心脏大小及功能恢复正常。结论儿童房速可经导管消融消除或获得明显改善。     

Focal atrial tachycardias arising from the right atrial appendage: electrocardiographic and electrophysiologic characteristics and radiofrequency ablation

Objective: To characterize the electrocardiographic and electrophysiological features and frequency of focal atrial tachycardia (AT) originating from the right atrial appendage (RAA).
Background: The RAA has been described as a site of origin of AT, but detailed characterization of these tachycardias is limited.
Methods: Ten patients (3.8%) of 261 undergoing radiofrequency ablation (RFA) for focal AT are reported. Endocardial activation maps (EAM) were recorded from catheters at the CS (10 pole), tricuspid annulus (20 pole Halo catheter), and His positions. P waves were classified as negative, positive, isoelectric, or biphasic.
Results: The mean age was 39 ± 20 years, nine males, with symptoms for 4.1 ± 5.1 years. Tachycardia was incessant in seven patients, spontaneous in one patient, and induced by programmed extrastimuli in two patients. These foci had a characteristic P wave morphology. The P wave was negative in lead V₁ in all patients, becoming progressively positive across the precordial leads. The P waves in the inferior leads were low amplitude positive in the majority of patients. Earliest EAM activity occurred on the Halo catheter in all patients. Mean activation time at the successful RFA site =−38 ± 15 msec. Irrigated catheters were used in six patients, due to difficulty achieving adequate power. RFA was acutely successful in all patients. Long-term success was achieved in all patients over a mean follow up of 8 ± 7 months.
Conclusions: The RAA is an uncommon site of origin for focal AT (3.8%). It can be suspected as a potential anatomic site of AT origin from the characteristic P wave and activation timing. Irrigated ablation catheters are often required for successful ablation. Long-term success was achieved with focal ablation in all patients.     

界嵴心动过速与房室结折返性心动过速并存时心房激动的竞争夺获现象

目的　阐明右心房内界嵴心动过速 (CT AT)与房室结折返性心动过速 (AVNRT)并存时心房激动的竞争夺获现象 ,分析其可能的电生理机制及导管消融策略。方法　 3例患者中 ,女性 2例 ,男性 1例 ,年龄 4 9～ 5 7岁 ,心动过速病史 10～ 2 0年。 3例患者均无器质性心脏病。经左股静脉置入 9F球囊电极至右心房中部并展开 ,球囊中心位于希氏束水平。构建右心房构型后 ,经高位右心房程序刺激诱发心动过速 ,建立心动过速的心内膜等电势图 ,然后分析心动过速的起源、传导方向 ,由此确定消融的部位和方法。经导航系统引导消融导管至拟订靶点处 ,每点予以 6 0W、6 0s、6 0℃温控消融 ,直至心动过速不能诱发。结果　 3例患者均可诱发出CT AT和AVNRT。例 1CT AT和AVNRT同时被诱发 ,两种心动周期比较接近 ,分别为 2 83ms和 2 6 2ms ;心内膜电生理提示心动过速由CT AT逐渐移行成AVNRT。例 2首先诱发出CT AT ,随之又诱发出AVNRT ,且两者并存 ,两种心动周期基本相同 ,分别为 35 0ms和 35 9ms;心内膜电生理示右心房上部随CT激动 ,下部及间隔部随AVNRT激动。例 3AVNRT比CT更易诱发 ,两者不在同一时间段出现 ,前者心动过速周期为 2 73ms ,后者为 36 5ms。3例患者均先行常规方法消融慢径 ,使AVNRT不再诱发。CT AT经非接触球囊导管