扩张型心肌病心脏再同步化治疗术后发作束支折返性室性心动过速的鉴别及消融一例

患者男,72岁,因宽QRS波心动过速在Rhythmia系统指导下行心内电生理检查及射频消融术,术中心房、心室刺激不能诱发心动过速,遂于心室内膜、外膜行基质标测,未标测到明显低电压区及晚电位区域.静脉滴注异丙肾上腺素后心房刺激诱发出心动过速,为长H V间期宽Q RS心动过速,心动过速发作过程中有室房分离现象,且心动过速H...     

房室结折返性心动过速经不同方式起搏的诱发率及电生理特性

探讨右房、右室刺激诱发房室结折返性心动过速(AVNRT)的规律及电生理特性。58例经食管调搏诊断为AVNRT的患者,在行射频导管消融(RFCA)前接受心内电生理检查(经右房、右室的程序期前刺激和分级递增刺激)。结果:38例经右房和右室刺激均可诱发,有13例仅能经心房刺激诱发,4例仅能经心室刺激诱发,其中3例仅能为心室分级递增刺激诱发;3例静脉点滴异丙肾上腺素或静脉注射阿托品后再次心房或心室刺激诱发;单纯经心室分级递增刺激诱发的AVNRT,其心房程序刺激的AH最大值(AHmax)短于心室分级递增刺激诱发AVNRT时的AH值及心动过速时的AH值(AHSVT)。而同时经心室及心房刺激诱发的心动过速,其AHmax长于仅能经心房刺激诱发AVNRT时AH值及AHSVT,P均<0.05。结论:多数AVNRT患者均可经右房和右室刺激诱发,能够引起足够长AH值的刺激部位及方法均可诱发AVNRT。     

阻断共同通道治疗房室结折返性心动过速与心房扑动的研究

目的 探讨房室结折返性心动过速(AVNRT)与心房扑动(AFL)的共同发病机制。方法 20例AVNRT并发AFL的患者通过电生理检查明确其心动过速性质后，行冠状窦口附近的慢径消融术(RFCA)，消融能量平均25W；术后在静脉滴注异丙肾上腺素下反复各种电刺激诱发，双径现象消失或无PSVT发作，视为手术成功。结果 20例患者术后及随访期内(3月～33月)，无AVNRT与AFL发作，亦无房室传导阻滞等并发症发生。结论 部分AVNRT并发AFL患者在返环途径上可能存在共同通道，RFCA可使其同时得到治疗。     

依赖异丙肾上腺素逆传的房室结折返性心动过速

目的探讨房室结双径路中的室房逆传和对房室结双径路的快径逆传间歇性的认识。方法对401例AVNRT者中,在基础状态下RVAS1S1>500ms为无室房逆传的13例患者进行异丙肾试验,重复电生理检查。结果401例AVNRT为慢快型,其中388例(96.8%)RVAS1S1<300ms,为有室房逆传组,而13例(3.2%)RVAS1S1>500ms,为无室房逆传组。结论AVNRT的病人中行电生理检查示房室结存在双径路而室房分离或室房传导时间长,在不能诱发心动过速时,应使用异丙肾上腺素以明确存在快径间歇性逆传的可能性。     

房室结折返性心动过速合并室性心动过速致患者反复晕厥一例

患者男性，57岁，13年前开始反复出现阵发性心悸不适，每次发作有突发突止的特点，发作时的心电图提示室上性心动过速。1年前开始，患者心动过速发作次数较以前明显增加，并先后5次发作心动过速后出现晕厥，入院行心内电生理检查证实患者室上性心动过速为房室结折返性心动过速(AVNRT),在电生理检查诱发AVNRT后，随即出现室性心动过速，患者发作晕厥1次，证实患者反复晕厥系AVNRT合并的室性心动过速所致，行AVNRT射频消融术后，患者未再发作心动过速，未再发作晕厥。     

不典型房室结折返性心动过速与房室折返性心动过速的电生理鉴别

房室结折返性心动过速(AVNRT)与房室折返性心动过速(AVRT)的鉴别有时较困难,尤其是不典型AVNRT与间隔旁道参与的AVRT鉴别,不典型AVNRT在心动过速发生时最早心房激动位于后间隔区域,与后间隔旁道引起的AVRT相似。通常检测房室结双径路的电生理方法仅能鉴别63%的不典型AVNRT。该文介绍了两者的主要电生理鉴别方法,包括希氏束旁起搏、在希氏束不应期给予心室期前程序刺激、心室或希氏束旁起搏后间期与心动过速周长之差(PPI-TCL)和刺激信号至心房波减去室房(SA-VA)间期的区别、校正的心室PPI-TCL和VA间期、心动过速时VA分离现象及TCL行心室起搏时的VA间期与心动过速时的VA间期之差等9种方法。     

依赖异丙肾上腺素逆传的房室折返性心动过速

目的：探讨4例依赖异丙肾上腺素逆传的房室折返性心动过速的发作情况及电生理特点。方法：对4例射频导管消融前常规电生理检查未能诱发出阵发性定性心动过速及A－H间期跳跃，亦未见旁道逆传者，静脉滴注异丙肾上腺素、右心室刺激时发现左侧旁道逆传，并均诱发出正向型房室折返性心运过速；停止注射后，左侧旁道逆传功能消失，亦不能诱发出房室折返性心动过速。结果：静脉滴注异丙肾上腺素，右心室起搏下用逆行法于二尖瓣环心室侧消融，4例均获成功；术后静脉滴注异丙肾上腺素下再行右心室起搏，未见旁道逆传现象。结论：部分隐匿性旁道构成的房室折返性心动过速发作依赖异丙肾上腺素，射频导管消融在静脉滴注异丙肾上腺素及右心室起搏下进行。     

射频消融房室结慢径术后迟发完全性房室阻滞一例

患者女性 ,5 2岁。因阵发性室上性心动过速 6年而入我院行射频消融术 ,术中心房程序刺激见房室结双径现象 ,但未能诱发室上性心动过速 (室上速 ) ,静脉滴注异丙肾上腺素后 ,心房短阵快速刺激反复诱发了室上速 ,心室率达 2 40次 /min,诊断为房室结折返性心动过速。消融电极于希氏束与冠状静脉窦口连线的下 1/3处标测到小 A大 V波 ,且无 H波 ,以 2 5 W功率射频消融即刻便出现交界区心律 ,并与窦性心律交替。一次性巩固消融 6 0 s。重复静脉滴注异丙肾上腺素和心房刺激 ,不再诱发心动过速 ,并且房室结双径现象消失 ,房室结前传文氏点由消融前…     

慢快型房室结内折返性心动过速伴下部共同径路2:1房室传导阻滞

慢快型房室结内折返性心动过速(AVNRT)在临床上较为常见。但房室结内形成的折返在下部共同径路存在传导障碍,而出现2∶1房室传导阻滞较为少见。我们在行食管电生理和心内电生理检查时遇见6例,现报道如下。资料和方法1.对象。1995年5月至2002年2月来院心内科门诊和住院患者6例,男性4例,女性2例,年龄34~65岁。均有心动过速发作史3～10年,发作时的体表心电图已确诊为房室结内折返性心动过速,准备行射频导管消融术。在术前和/或术中的检查中发现慢快型房室结内折返性心动过速,发作时呈2∶1房室传导阻滞。2.方法。以习用的食管电生理和心内电生…     

快慢型房室结折返性心动过速的电生理特点

目的分析快慢型房室结折返性心动过速（AVNRT）患者的临床特征、心电网和电生理检查特点、射频消融治疗特点,旨在为临床长RP。心动过速鉴别提供帮助。方法11例经心内电生理检查证实为慢快型房室结折返性心动过速的患者,回顾性分析其临床特征、心电图特点及电生理检查特点及射频消融治疗。结果心动过速表现为窄QRs波心动过速,RP’〉P’R,P。在Ⅱ、Ⅲ、aVF导联倒置,RP’间期为350±25ms,心率为1664-30bpm。11例患者中有3例出现室房逆传跳跃现象。心房程序刺激无明显跳跃现象,11例均可由心房StS：刺激诱发心动过速发作,且容易诱发,容易终止。心动过速发作时,5例CS9．10A波最早,6例HiS的A波最早,其中1例静推ATP心动过速终止。11例患者中9例经房室结改良消融传统慢径获得成功,2例在冠状静脉窦内消融成功,术后随访3个月以上均未再发作心动过速。结论长RP’心动过速的诊断和鉴别诊断有一定困难,如能排除慢旁道和房速,应考虑快慢型房室结折返性心动过速。     

Unique electrophysiologic characteristics of atrioventricular nodal reentrant tachycardia with different ventriculoatrial block patterns: Effects of slow pathway ablation and insights into the location of the reentrant circuit

BACKGROUND: The electrophysiologic mechanisms of different ventriculoatrial (VA) block patterns during atrioventricular nodal reentrant tachycardia (AVNRT) are poorly understood. OBJECTIVES: The purpose of this study was to characterize AVNRTs with different VA block patterns and to assess the effects of slow pathway ablation. METHODS: Electrophysiologic data from six AVNRT patients with different VA block patterns were reviewed. RESULTS: All AVNRTs were induced after a sudden AH "jump-up" with the earliest retrograde atrial activation at the right superoparaseptum. Different VA block patterns comprised Wenckebach His-atrial (HA) block (n = 4), 2:1 HA block (n = 1), and variable HA conduction times during fixed AVNRT cycle length (CL) (n = 1). Wenckebach HA block during AVNRT was preceded by gradual HA interval prolongation with fixed His-His (HH) interval and unchanged atrial activation sequence. AVNRT with 2:1 HA block was induced after slow pathway ablation for slow-slow AVNRT with 1:1 HA conduction, and earliest atrial activation shifted from right inferoparaseptum to superoparaseptum without change in AVNRT CL. The presence of a lower common pathway was suggested by a longer HA interval during ventricular pacing at AVNRT CL than during AVNRT (n = 5) or Wenckebach HA block during ventricular pacing at AVNRT CL (n = 1). In four patients, HA interval during ventricular pacing at AVNRT CL was unusually long (188 +/- 30 ms). Ablations at the right inferoparaseptum rendered AVNRT noninducible in 5 (83%) of 6 patients. CONCLUSION: Most AVNRTs with different VA block patterns were amenable to classic slow pathway ablation. The reentrant circuit could be contained within a functionally protected region around the AV node and posterior nodal extensions, and different VA block patterns resulted from variable conduction at tissues extrinsic to the reentrant circuit.     

Significance of bundle branch block during atrioventricular nodal reentrant tachycardia

There are very limited data on the effects of bundle branch block (BBB) in patients with atrioventricular nodal reentrant tachycardia (AVNRT). Studies in a total of 155 patients with 162 episodes of AVNRT were retrospectively analyzed. A total of 38 patients (25%) developed spontaneous right BBB, whereas 5 (3%) developed left BBB during tachycardia. Five of the 38 (13%) with right BBB showed near identical prolongation of both the ventriculoatrial (VA) (15 +/- 5 ms; 10 to 23) and His to atrial intervals (HA) (14 +/- 4 ms; 10 to 20) with an identical atrial activation sequence for both right BBB or normal QRS tachycardia complexes. In contrast, all 5 patients with left BBB showed a decrease in the VA (-18 +/- 11 ms; 10 to 36) with unchanged HA comparing left BBB to normal QRS patterns during AVNRT. The magnitude of prolongation of the His to ventricular interval (HV) during left BBB (19 +/- 12 ms; 10 to 40) was nearly identical to the decrease in the VA. In conclusion, prolongation of VA and HA with unchanged HV in patients with AVNRT and right BBB suggests that right BBB is due to a block in the fibers in close proximity to the His recording site. The data suggest that fibers in the His bundle are predestined to activate the right bundle branch, and in AVNRT the lower turnaround point may be within the His bundle.     

Atrioventricular nodal reentrant tachycardia with ventriculoatrial block and unsuccessful ablation of the slow pathway

We report the case of failed slow pathway ablation in a woman with typical AV nodal reentrant tachycardia (AVNRT) and periods of Wenckebach-like second-degree VA block and 2:1 VA block. The occurrence of VA block during AVNRT suggests the upper turnaround point of the circuit is confined to the AV node. This supports the notion that, at least in some cases, the location of the reentrant circuit for AVNRT is completely in the compact AV node.     

Target Temperatures of 48°C versus 60°C During Slow Pathway Ablation:

INTRODUCTION: The relationship between temperature at the electrode-tissue interface and the loss of AV and ventriculoatrial (VA) conduction is not established, and the optimal target temperature for the slow pathway approach to radiofrequency ablation of AV nodal reentrant tachycardia (AVNRT) is unknown. Therefore, the purpose of this study was to compare target temperatures of 48 degrees C and 60 degrees C during the slow pathway approach to ablation of AVNRT. METHODS AND RESULTS: The study included 138 patients undergoing ablation for AVNRT. Patients undergoing slow pathway ablation using closed-loop temperature monitoring were randomly assigned to a target temperature of either 48 degrees C or 60 degrees C. The primary success rates were 76% in the patients assigned to 48 degrees C and 100% in the patients assigned to 60 degrees C (P < 0.01). The ablation procedure duration (33 +/- 31 min vs 26 +/- 28 min; P = 0.2), fluoroscopic time (25 +/- 15 min vs 24 +/- 16 min; P = 0.5), and mean number of applications (9.3 +/- 6.5 vs 7.8 +/- 8.1; P = 0.3) were similar in patients assigned to 48 degrees and 60 degrees C, respectively. The mean temperature (46.1 degrees +/- 24.8 degrees C vs 48.7 +/- 3.2 degrees C; P < 0.01), the temperature associated with junctional ectopy (48.1 degrees +/- 2.0 degrees C vs 53.5 degrees +/- 3.5 degrees C, P < 0.0001), and the frequency of VA block during junctional ectopy (24.6% vs 37.2%; P < 0.0001) were less in the patients assigned to 48 degrees C compared to 60 degrees C. The frequency of transient or permanent AV block was similar in each group (2.8% vs 3.6%; P = 0.2). In the 60 degrees C group, only 12% of applications achieved an electrode temperature of 60 degrees C. During follow-up of 9.9 +/- 4.2 months, there was one recurrence of AVNRT in the 48 degrees C group and none in the 60 degrees C group. CONCLUSIONS: Compared to 48 degrees C, a target temperature of 60 degrees C during radiofrequency slow pathway ablation is associated with a higher primary success rate and a higher incidence of VA block during junctional ectopy induced by the radiofrequency energy. AV block is not more common with the higher target temperature, but only if VA conduction is aggressively monitored during applications of radiofrequency energy.     

Sequence of electrical activation, atrial remodelling and atrial fibrillation in patients with nodal re-entrant tachycardia

OBJECTIVE: The objective of the study was to verify, if the particular sequence of electrical atrioventricular activation during tachycardia is associated with the development of atrial remodelling and predisposition to atrial fibrillation (AF) in patients with nodal reentry tachycardia (AVNRT). METHODS AND RESULTS: We assessed 117 consecutive patients with AVNRT identified during electrophysiological study. Two groups were identified: the AF group, n = 21 (17.9%, median age 46.0, 15 women), with clinically documented AF, and the control group, n = 96, without AF (median age 48.5, 69 women). Tachycardia cycle length (VV), anterograde AV, retrograde VA activation intervals and indexes (AV/VV, VA/VV) during AVNRT, atrial refractory period (AERP), intraatrial (IntraCT) and interatrial conduction time (InterCT) of the sinus beat and premature stimuli were analysed. The longer retrograde and shorter anterograde activation was found in AF patients with typical AVNRT, the opposite relations showed the subjects with atypical tachycardia. Intra and InterCT of sinus beat, and of paced extrastimuli were longer, AERP was borderline shorter in the AF-group than in the controls.The longest conduction times and shortest AERP were seen in the patients with VA/VV within 20-40% of the tachycardia cycle, this group comprised 71% of all AF-patients (P< 0.001).VA was predictive for AF in typical (OR/unit 1.04) and atypical AVNRT (OR/unit 0.93, P< 0.05). CONCLUSIONS: The particular sequence of electrical atrioventricular activation, seen in some patients during AVNRT, is associated with disturbances of atrial conduction, refractoriness and predisposes to atrial fibrillation.     

Paroxysmal regular supraventricular tachycardia: the diagnostic accuracy of the transesophageal ventriculo-atrial interval

Objective: To establish the diagnostic accuracy of the transesophageal ventriculo‐atrial (VA) interval in patients with paroxysmal supraventricular tachycardia (PSVT) and normal baseline electrocardiogram (ECG). Methods: The transesophageal VA interval during tachycardia was recorded in 318 patients (age 45 ± 17 years, 58% female) with PSVT and a normal surface ECG between attacks. Subsequently, all patients underwent an ablation procedure establishing the correct tachycardia diagnosis. Results: AV nodal reentrant tachycardia (AVNRT), AV reentrant tachycardia through a concealed accessory pathway (AVRT), and ectopic atrial tachycardia (EAT) were found in 213, 95, and 10 cases, respectively. Receiver operating characteristic curve analysis identified an optimal cutoff for a binary categorization of AVNRT versus AVRT/EAT at ≤80 ms (area under the curve 0.891). Owing to a biphasic distribution, AVNRT was very likely at VA intervals ≤90 ms with a sensitivity, specificity, and positive predictive value (PPV) of 87%, 91%, and 95%. In the range 91–160 ms the corresponding values for AVRT were 88%, 95%, and 88% (90%, 99%, and 98% in male patients). In the small group with VA intervals >160 ms (n = 29), the diagnosis was less clear (PPV of 67% for AVNRT). Conclusions: In patients with sudden onset regular tachycardia and a normal ECG during sinus rhythm, a transesophageal VA interval of ≤80 ms has the highest diagnostic accuracy to diagnose AVNRT versus AVRT/EAT. Overall, the biphasic distribution of VA intervals suggests considering AVNRT at 90 ms and below and AVRT between 91 and 160 ms (in particular in male patients) while the diagnosis is vague at VA intervals above 160 ms. Ann Noninvasive Electrocardiol 2011;16(4):327–335     

Paroxysmal supraventricular tachycardia with persistent ventriculoatrial block

We report the case of a 64-year-old patient with paroxysmal supraventricular tachycardia and persistent VA block. Induction and maintenance of tachycardia occurred without apparent activation of the atria. Diagnostic characteristics were most compatible with AV nodal reentrant tachycardia (AVNRT). Automatic junctional tachycardia and orthodromic nodoventricular or nodofascicular reentry tachycardia were considered in the differential diagnosis. Upper common pathway block during AVNRT may be explained by either intra-atrial conduction block or purely intranodal confined AVNRT. The arrhythmia was cured by a typical posteroseptal ablation approach guided by slow pathway potentials.     

房室结改良时发生完全性房室阻滞的特征性心电改变

探讨经导管射频消融 (RFCA)治疗房室结折返性心动过速 (AVNRT)时发生完全性房室阻滞 (Ⅲ度AVB)前的特征性心电改变。回顾分析自 1996年 1月至 1999年 12月RFCA治疗AVNRT放电过程有完整心内电图记录者 486例。放电过程中有室房 (VA)阻滞、快速交界心律 (≥ 16 0bpm)和 /或房室 (AV)阻滞称为特征性心电改变。Ⅰ组 387例 ,任何一次放电过程中无特征性心电改变 ;Ⅱ组 99例 ,有一次或一次以上放电过程中有特征性心电改变。Ⅱ组中有特征性心电改变的放电共 316次 ,即刻停止放电组 (Ⅱa组 ) 2 19次 ,指发现特征性心电改变后 2s以内停止放电 ;延迟停止放电组 (Ⅱb组 ) 97次 ,指发现特征性心电改变 2s后停止放电。结果 :①AVNRT消融总成功率 97.9%(4 76 /4 86 ) ,永久性Ⅲ度AVB 0 .41% (2 /4 86 )。②特征性心电改变中VA阻滞占 72 .5 % (2 2 9/316 )、快交界心律占2 0 .6 % (6 5 /316 )、AV阻滞占 7.0 % (2 2 /316 )。③Ⅲ度AVB(包括一过性和永久性 )发生率为 2 .3% (11/4 86 ) ,其中Ⅰ组为 0 (0 /387)、Ⅱ组为 11.1% (11/99) ,P <0 .0 0 0 1。④Ⅱa组Ⅲ度AVB发生率为 0 .9% (2 /2 19)、Ⅱb组Ⅲ度AVB发生率为 9.3% (11/97) ,P <0 .0 0 1。RFCA改良房室结治疗AVNRT时Ⅲ度AVB均发生在特征性心电改变之后 ,发现特征?     

Percutaneous catheter modification of the atrioventricular node. A potential cure for atrioventricular nodal reentrant tachycardia

Our purpose was to describe a technique of atrioventricular (AV) node modification for patients with drug refractory AV nodal reentrant tachycardia (AVNRT). Nine patients (mean age, 45 +/- 20; range, 14-82) with recurrent drug refractory AVNRT (n = 8) or sudden cardiac death thought to be precipitated by AVNRT (n = 1) underwent a percutaneous catheter procedure to modify AV nodal function. The area between the electrode recording the maximal His-bundle electrogram and the ostium of the coronary sinus was divided into three zones. Perinodal direct current shocks of 100-300 J were delivered to one (n = 2), two (n = 3), or three (n = 4) zones without complications. The procedure endpoints were modification of AV conduction (either first degree AV block or complete retrograde ventriculo-atrial [VA] block) and failure to induce AVNRT before or after isoproterenol and/or atropine administration. Six of nine patients (67%) have had no inducible or spontaneous AVNRT over a mean follow-up of 12.3 +/- 4.1 months (range, 4.5-17). One of the six underwent repeat, successful modification, because AVNRT was inducible at restudy 2 days after the initial procedure. AVNRT recurred in three patients (33%), one early (3 days) and two late (3-4 months). Two of these patients underwent complete ablation of the AV junction and permanent pacemaker placement, whereas one is controlled with drug therapy. Therefore, AV nodal modification resulted in tachycardia control without antiarrhythmic drugs in six of nine (67%) and obviated the need for complete AV junctional ablation in seven of nine patients (78%). Elimination of AVNRT appears to result from either block in the retrograde fast pathway or modification of the antegrade slow pathway, such that AVNRT cannot be sustained. Additional findings suggest that an atrio-Hisian accessory connection may not be involved in AVNRT in some of these patients. Percutaneous catheter AV nodal modification appears to be a promising technique for treatment of refractory AVNRT and may obviate need for complete AV junctional ablation in a substantial number of patients with drug/pacemaker refractory AVNRT.     

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.