肺静脉前庭隔离联合左心房线性及碎裂电位消融治疗持续性心房颤动的临床研究

目的探讨肺静脉前庭隔离联合线性及碎裂电位消融治疗持续性心房颤动（房颤）的有效性与安全性。方法共45例持续性房颤患者入选本研究（其中长时程持续性房颤28例）,男性32例,女性13例,年龄（58.8±9.0）岁,病程（23.3±22.4）个月。消融步骤是先行肺静脉前庭隔离,后行线性消融,最后行心房碎裂电位消融。术后所有患者均给予服用培哚普利4 mg/d和抗心律失常药物3个月。甲状腺功能异常者,给予普罗帕酮450 mg/d,共3个月;术前未用胺碘酮者,术后即刻静点胺碘酮1 mg/min,6 h后减量为0.5 mg/min维持42 h,同时口服0.6 g/d连续1周,继之0.4 g/d连续1周,以后0.2 g/d,共3个月;术前口服胺碘酮患者,术后继续口服,0.2 g/d,共3个月。结果消融术中有9例房颤终止,2例先转变为三尖瓣峡部依赖性心房扑动,峡部消融后转为窦性心律（窦律）;3例转为房性心动过速（房速）,最早激动点或者关键峡部消融后转复为窦律;其余患者均行电复律转复为窦律。平均随访（18.2±9.2）个月,共12例患者发作房性心律失常;复发房颤3例,房速9例。结论持续性房颤患者,肺静脉前庭隔离联合左房线性及碎裂电位消融能够破坏更多的维持机制,是治疗持续性房颤的安全、有效的方法。     

The 1998 NASPE prospective catheter ablation registry

The results of the NASPE Prospective Voluntary Registry are reported. A total of 3,357 patients were entered. For those undergoing atrioventricular (AV) junctional ablation (646 patients), the success rate was 97.4% and significant complications occurred in 5 patients. A total of 1,197 patients underwent AV nodal modification for AV nodal reentrant tachycardia, which was successful in 96.1% and the only significant complication was development of AV block (1%). Accessory pathway ablation was performed in 654 patients and was successful in 94%. Major complications included cardiac tamponade (7 patients), acute myocardial infarction (1 patient), femoral artery pseudoaneurysm (1 patient), AV block (1 patient), pneumothorax (1 patient), and pericarditis (2 patients). A total of 447 patients underwent atrial flutter ablation and acute success was achieved in 86% of patients. Significant complications included inadvertent AV block (3 patients), significant tricuspid regurgitation (1 patient), cardiac tamponade (1 patient), and pneumothorax (1 patient). Atrial tachycardia was attempted for 216 patients and the success rate was higher for those with right atrial (80%) or left atrial (72%) compared to those with septal foci (52%). A total of 201 patients underwent ablation for ventricular tachycardia. The success rate was higher for those with idiopathic ventricular tachycardia compared to those with ventricular tachycardia due to ischemic heart disease or cardiomyopathy. While the number of AV junction ablation were higher for those > 60 years of age, there was no significant difference in the success rate or incidence of complication comparing patients > or = 60 to those < 60 years of age. In addition, we found no differences in incidence of success or complications comparing large volume centers (> 100 ablation/year) with lower volume centers or between teaching and non-teaching hospitals.     

High‐density characterization of a localized reentry circuit occurred after AF ablation

We present the case of a localized reentry circuit that developed 24 h after radiofrequency ablation of atrial fibrillation (AF). The circuit was of interest because it overlapped with sites of previous defragmentation during AF. The circuit presented a small funnel that measured only 1.4 mm at its narrowest segment. Fractionated signals, which codify for slow conduction zones, corresponded to the isthmus site. Ablation at this site interrupted the atrial tachycardia.     

Noncavotricuspid isthmus-dependent right atrial tachycardia after paroxysmal atrial fibrillation ablation

Background: Atrial tachycardia (AT) is commonly encountered after atrial fibrillation (AF) ablation. But no study exclusively on noncavotricuspid isthmus‐dependent right AT (NCTI‐RAT) post‐AF ablation has been reported. The present study aims to describe its prevalence, electrophysiological mechanisms, and ablation strategy and to further discuss its relationship with AF. Methods: From July 2006 to November 2009, 350 consecutive patients underwent catheter ablation for paroxysmal AF. A total of seven patients (2.0%) developed NCTI‐RAT after left atrium ablation for AF. In these highly selected patients (two male, mean age 54 ± 11 years, mean left atrium diameter of 34 ± 7 cm), all had circumferential pulmonary vein isolation in their initial procedures and three of them had additional complex fractionated electrograms ablation in the left atrium and the coronary sinus. Results: Totally, nine NCTI‐RATs were mapped and successfully ablated in the right atrium with a mean cycle length of 273 ± 64 ms in seven patients. Five ATs in three patients were electrophysiologically proved to be macroreentry and the remaining four were focal activation. All the ATs were successfully abolished by catheter ablation. After a mean follow‐up of 29 ± 15 months post‐AT ablation, all patients were free of AT and AF off antiarrhythmic drugs. Conclusions: NCTI‐RAT is relatively less common post‐AF ablation. Totally, 2.0% of paroxysmal AF patients were revealed to have NCTI‐RAT. (PACE 2011; 34:391–397)     

A case of persistent atrial fibrillation cured by focal ablation in a young patient

We present a case of a 25-year-old man who had persistent atrial fibrillation (AF) lasting for three months. The persistent AF was terminated by a 20-mg bolus infusion of adenosine triphosphate. Frequent and repetitive episodes of ectopic atrial tachycardia (EAT) emerged from the mid-portion of the saddle between the left superior and inferior pulmonary veins. The successful ablation was achieved by a focal ablation at the site with the earliest activation preceding the P-wave onset by 42 ms, and exhibited a QS pattern in the unipolar recording. This is rare case in which focal ablation could cure persistent AF.     

Impact of varying ablation patterns in a simulation model of persistent atrial fibrillation

BACKGROUND: Several strategies of endovascular ablation with varying success rates and proarrhythmic effects have been proposed to treat persistent atrial fibrillation (AF). Evaluation of ablation patterns by computer simulation provides a tool for examination of its effectiveness and side effects. METHODS AND RESULTS: A biophysical model of the human atria based on magnetic resonance imaging derived geometry and a membrane kinetics model was used. Uniform conduction properties were assigned to the monolayer surface representing the atria. After induction of AF by burst pacing, progressively broader ablation patterns were applied: (A) individual pulmonary vein isolation (PVI); (B) double ipsilateral PVI; (C) double PVI with a roofline; (D) double PVI with a lateral mitral isthmus line, and (E) double PVI with both linear lesions. In addition, the influence of incomplete linear lesions and dilated atria were simulated. The incidence of AF termination was found to increase from pattern (A) to (E). Atrial flutter rate increased with incomplete ablations and in dilated atria. CONCLUSION: Computer simulation of various ablation patterns in persistent AF is feasible and can reproduce clinical results of catheter ablation. This model can be used to develop and simulate new ablation patterns and anticipate success rates and potential adverse effects.     

环肺静脉电隔离术对心房颤动患者左心房、左心耳、左心房顶部结构的影响

目的应用64排螺旋CT观察环肺静脉电隔离（CPVA）术对心房颤动患者左心房（LA）、左心耳（LAA）、LA顶部结构的影响。方法心房颤动患者共28例,行CPVA术3~14.8（6.5±3.9）个月后进行随访,根据术后有无复发分为成功组（22例）和复发组（6例）。应用64排螺旋CT测量CPVA术前、后LA[包括LA横径（LA1）、上下径（LA2）和前后径（LA3）、LA容积]、LAA（包括LAA口长径、短径和面积、LAA长度、LAA容积）、LA顶部（包括LA顶长度、距离和深度）的相关径线。结果成功组CPVA术后的LA1、LA2、LA3、LA容积、LAA口长径、LAA口面积、LAA容积、LAA长度、LA顶长度、LA顶距离术后比术前减小,术前术后分别为LA1（6.97±0.87）cm vs（6.32±0.94）cm,LA2（6.02±0.84）cm vs（5.63±0.63）cm,LA3（3.71±0.64）cm vs（3.46±0.59）cm,LA容积（83.61±25.98）cm3vs（66.11±22.84）cm3,LAA口长径（3.01±0.54）cm vs（2.64±0.62）cm,LAA口面积（4.99±1.79）cm2vs（4.11±1.94）cm2,LAA容积（11.11±4.34）cm3vs（9.59±4.82）cm3,LAA长度（3.99±0.84）cm vs（3.74±0.82）cm,LA顶长度（4.02±0.89）cm vs（3.55±0.76）cm,LA顶距离（3.90±0.88）cm vs（3.43±0.73）cm（均P〈0.05）;LAA口短径和LA顶深度无明显变化（P〉0.05）。复发组CPVA术前、后比较,除了LA2较术前减小（6.43±1.04）cm vs（5.92±1.27）cm（P〈0.05）,余LA、LAA、LA顶部结构无明显变化（P〉0.05）。结论成功组CPVA术后的LA、LAA、LA顶部较术前减小,即结构重构可以逆转;而复发组CPVA术前、后比较LA、LAA、LA顶部无明显变化,未出现逆重构。     

Treatment of sustained left atrial tachycardia by ostial pulmonary vein isolation

This report describes two patients with sustained regular left atrial tachycardias originating from multiple pulmonary veins in the absence of clinical evidence of atrial fibrillation. The tachycardias were eliminated by activation map-guided pulmonary vein isolation. Stable sustained regular pulmonary vein tachycardias unassociated with atrial fibrillation are uncommon, and they belong to the spectrum of pulmonary vein arrhythmias that include the more common paroxysmal and unstable tachycardias engendering atrial fibrillation.     

Case report: Cryoballoon ablation of the mitral isthmus using a novel mapping system

Perimitral atrial flutter is commonly treated by deployment of a mitral isthmus line. However, the creation of a contiguous, transmural linear lesion across the anterior mitral isthmus using radiofrequency energy ablation is technically challenging and can be associated with major complications. Herein, we describe the successful deployment of a superolateral mitral isthmus line using the 28‐mm cryoballoon in combination with a new mapping system.     

Early recurrence of atrial tachyarrhythmias following radiofrequency catheter ablation of atrial fibrillation

The use of blanking periods, the immediate period postablation during which transient tachyarrhythmia episodes are not considered recurrences, has been predicated on the assumption that not all early recurrences of atrial tachyarrhythmias (ERAT) will lead to later recurrences and, as such, does not necessarily represent treatment failure. While ERAT can be expected to occur in approximately 38% of patients within the first 3 months of atrial fibrillation (AF) ablation, only half of these patients will manifest later recurrences. Clinical features related to the patient's history of AF, the index ablation procedure, and particularities of the ERAT can help identify patients at higher risk of later recurrence in whom aggressive attempts to control rhythm, including early cardioversion and reintervention, may be justified.     

Blocking the pulmonary vein to left atrium conduction in addition to the entrance block enhances clinical efficacy in atrial fibrillation ablation

Background: The unidirectional pulmonary vein (PV) to left atrium (LA) conduction after achieving PV entrance block has not been evaluated. Methods: Circumferential PV isolation was performed in 573 consecutive patients with atrial fibrillation (AF). The unidirectional PV to LA conduction and its influence on clinical outcomes were evaluated. Results: A total of 341 ipsilateral PVs (29.7%) with spontaneous activities (SAs) were documented in 231 patients (40.3%). The unidirectional PV to LA conduction was confirmed in 11 ipsilateral PVs (3.2%) of 11 patients (4.8%). Patients were classified to three groups: Group A (had unidirectional PV to LA conduction during SAs), Group B (with SAs but without PV to LA conduction), and Group C (without SAs). During a 30‐minute observation, the reconnection incidence was higher in Group A (45.4%) than in Group B (13.9%, P = 0.042) and Group C (11.5%, P = 0.018). The reconnection time was shorter in Group A (10.8 ± 9.8 minutes) than that in Group B (20.7 ± 8.0 minutes, P = 0.037) and Group C (21.2 ± 8.2 minutes, P = 0.022). All 11 PVs were successfully isolated and bidirectional block was achieved. Conclusion: Unidirectional entrance block with SAs in PVs may not be a good indication of complete PV isolation. Bidirectional block of the PV‐LA junction can reduce the acute PV reconnection and may reduce the chronic AF recurrence in patients undergoing circumferential PV isolation.(PACE 2012; 1–8)     

Atrial fibrillation ablation using a closed irrigation radiofrequency ablation catheter

Background: Catheter ablation is an effective therapy for symptomatic, medically refractory atrial fibrillation (AF). Open‐irrigated radiofrequency (RF) ablation catheters produce transmural lesions at the cost of increased fluid delivery. In vivo models suggest closed‐irrigated RF catheters create equivalent lesions, but clinical outcomes are limited. Methods: A cohort of 195 sequential patients with symptomatic AF underwent stepwise AF ablation (AFA) using a closed‐irrigation ablation catheter. Recurrence of AF was monitored and outcomes were evaluated using Kaplan–Meier survival analysis and Cox proportional hazards models. Results: Mean age was 59.0 years, 74.9% were male, 56.4% of patients were paroxysmal and mean duration of AF was 5.4 years. Patients had multiple comorbidities including hypertension (76.4%), tobacco abuse (42.1%), diabetes (17.4%), and obesity (mean body mass index 30.8). The median follow‐up was 55.8 weeks. Overall event‐free survival was 73.6% with one ablation and 77.4% after reablation (reablation rate was 8.7%). Median time to recurrence was 26.9 weeks. AF was more likely to recur in patients being treated with antiarrhythmic therapy at the time of last follow‐up (recurrence rate 30.3% with antiarrhythmic drugs, 13.2% without antiarrhythmic drugs; hazard ratio [HR] 2.2, 95% confidence interval [CI] 1.1–4.4, P = 0.024) and in those with a history of AF greater than 2 years duration (HR 2.7, 95% CI 1.1–6.9, P = 0.038). Conclusions: Our study represents the largest cohort of patients receiving AFA with closed‐irrigation ablation catheters. We demonstrate comparable outcomes to those previously reported in studies of open‐irrigation ablation catheters. Given the theoretical benefits of a closed‐irrigation system, a large head‐to‐head comparison using this catheter is warranted. (PACE 2012; 35:506–513)     

Intraprocedural imaging of left atrium and pulmonary veins: a comparison study between rotational angiography and cardiac computed tomography

Background: Atrial fibrillation (AF) ablation is facilitated by anatomical visualization of the left atrium (LA) and the pulmonary veins (PVs). The purpose of this study was to compare accuracy, radiation exposure, and costs between three‐dimensional atriography (3D‐ATG) and cardiac computed tomography (CCT). Methods: Seventy patients with an indication for AF ablation were included. Contrast‐enhanced CCT was performed preoperatively for all patients. In addition, intraoperative 3D‐ATG was performed with contrast medium injection either indirectly into the pulmonary arteries during a breath‐hold (Ind.‐RTA, n = 25) or directly into the LA, during adenosine‐induced asystole (Ad.‐RTA, n = 23), or rapid ventricular pacing (VP‐RTA, n = 22). We evaluated vertical ostial PV diameters and LA volume, time needed to perform, radiation exposure, and procedural cost for each imaging method. Results: The correlation coefficient between 3D‐ATG and CCT for the ostial PV diameters was r = 0.83 for Ind.‐RTA, 0.91 for Ad.‐RTA, and 0.88 for the VP‐RTA method (P > 0.05). The volume correlations were r = 0.87 for Ind.‐RTA, 0.82 for Ad.‐RTA, and 0.8 for VP‐RTA (P > 0.05). Time to perform was 13 ± 5 minutes for ATG and 46 ± 9 minutes for CCT (P < 0.05). Effective radiation dose was 2.2 ± 0.2 mSv for ATG and 20.4 ± 7.4 mSv for CCT (P < 0.05). The procedural cost was estimated at 91–95 € for ATG and at 126–151 € for CCT. Conclusions: 3D‐ATG is an intraprocedural imaging modality that provides anatomical accuracy comparable to that of CCT with significantly lower radiation dose, in less time and at less financial expense (PACE 2011; 34:315–322)     

Change in morphology of reentrant atrial arrhythmias without termination following radiofrequency catheter ablation

A 60-year-old woman who had previously undergone an atrial septal defect repair and had type I atrial flutter underwent electrophysiological study. After radiofrequency (RF) ablation to the isthmus between the inferior vena cava and the tricuspid annulus, type I atrial flutter was changed to atrial tachycardia following atriotomy without termination. This atrial tachycardia was eliminated by single-site RF ablation of a small lesion below the caudal end of the atriotomy scar, where continuous and fragmented potentials were recorded during tachycardia. We experienced a rare case in which RF energy changed tachycardia circuits.     

Atrial tachycardias following circumferential pulmonary vein ablation: observations during catheter ablation

Circumferential pulmonary vein ablation performing linear lesions around the ostia of the pulmonary veins has been shown to be effective for the treatment of atrial fibrillation. During the follow-up period, persistent atrial tachycardia may occur as a proarrhythmic complication. Only little information is available about the underlying mechanism. In our study, atrial tachycardia following circumferential pulmonary vein ablation was identified in 13 out of 84 consecutive patients (15.5%), as a transient appearance in four and with recurrences for more than 3 months in nine patients (10.7%). Electrophysiological study and ablation was performed in eight cases, revealing common atrial flutter in two, a focal origin secondary to conduction recovery from the pulmonary vein to the left atrium in two and macro reentrant left atrial flutter in four patients. The electrophysiological characteristics demonstrated by electroanatomic activation mapping (CARTO™) and consecutive ablation therapy with a 100% success rate are described and discussed with regard to the literature.     

Ablation of epicardial right ventricular tachycardia provoked by proarrhythmic RV pacing in a patient with dilated cardiomyopathy

Ventricular arrhythmias are common in the setting of nonischemic dilated cardiomyopathy (NIDCM). However, the characterization of the substrate and mechanism of epicardial ventricular tachycardia (VT) associated with NIDCM is limited, and to the best of our knowledge VT due to myocardial reentry within the right ventricular (RV) epicardium associated with NIDCM has not been reported. We report a case of RV epicardial VT provoked by RV pacing that was successfully ablated.     

Atrial Tachycardia as a Proarrhythmic Effect of Radiofrequency Catheter Ablation for Atrioventricular Nodal Reentrant Tachycardia

Radiofrequency catheter ablation is now the first line treatment for atrioventricular nodal reentrant tachycardia. The success rate is high with a low incidence of complications. However, a possible proarrhythmic effect of radiofrequency energy has been rarely reported and no study has demonstrated a direct correlation between the anatomic site of the radiofrequency application and the origin of a new post‐ablation arrhythmia. We present a case of a focal atrial tachycardia that occurred after slow pathway radiofrequency catheter ablation for atrial nodal reentrant tachycardia and originating close to the previous ablation site. This tachycardia was successfully treated with a second ablation session. (PACE 2011; 34:e33–e37)     

Left atrial appendage isolation during ablation in the interatrial septum: Rapid recognition by continuous monitoring of appendage electrograms

Extensive atrial ablation in the setting of atrial fibrillation (AF) and atrial tachycardia (AT) can affect interatrial connections. A 76-year-old man with a history of tachycardia-induced cardiomyopathy and nine ablation procedures for AF/AT over 15 years presented with highly symptomatic recurrent AT. Previous ablation lesions included pulmonary vein isolation, left atrial posterior wall isolation, mitral isthmus line, cavotricuspid isthmus line, and the ablation of areas of fractionated electrograms. Electroanatomical mapping found the pulmonary veins and the left atrial posterior wall to be silent, as was the posterior interatrial septum and the mitral isthmus area. Activation mapping showed progression of electrograms in the left atrial appendage (LAA) from the septal aspect posteriorly, and in the coronary sinus from proximal to distal; implying the existence of a septal circuit, where extensive fractionation was noted. This was targeted, while monitoring conduction into the LAA using a multielectrode catheter. Ablation led to prompt termination of tachycardia and simultaneous LAA isolation. Immediate cessation of ablation led to recovery of conduction into LAA. Additional lesions in the interatrial septum were required to render the tachycardia noninducible, accompanied by temporary isolation of LAA. The ablation lesion sets employed while ablating AF and left AT can block many interatrial pathways, rendering conduction dependent on muscle bundles in the interatrial septum and, therefore, vulnerable to block by lesions in this area. LAA isolation has been associated with high incidence of LAA thrombus formation and stroke despite oral anticoagulation. Continuous observation of LAA electrograms during ablation can help to avoid this complication.