Pulmonary vein electrogram characteristics in patients with focal sources of paroxysmal atrial fibrillation

INTRODUCTION: The major source of ectopic beats initiating paroxysmal atrial fibrillation (AF) is from pulmonary veins (PVs). However, the electrogram characteristics of PVs are not well defined. METHODS AND RESULTS: Group I consisted of 129 patients with paroxysmal AF. Group II consisted of 10 patients with a concealed left-sided free-wall accessory pathway. All group I patients had spontaneous AF initiated by ectopic beats, including 169 ectopic foci originating from the PVs. We analyzed PV electrograms from the 169 ectopic foci during sinus beats and ectopic beats. During AF initiation, most (70%) ectopic beats showed PV spike potential followed by atrial potential; 16% of ectopic beats showed PV fragmented potential followed by atrial potential; and 14% showed fusion potentials. The coupling interval between the sinus beat and the ectopic beat was significantly shorter in the inferior PVs than in the superior PVs (171 +/- 48 msec vs 222 +/- 63 msec, P = 0.001) and was significantly shorter in the distal foci than in the ostial foci of PVs (206 +/- 52 msec vs 230 +/- 56 msec, P = 0.01). The incidence of conduction block in the PVs during AF initiation was significantly higher in the inferior PVs than in the superior PVs (12/24 vs 37/145, P = 0.03) and was significantly higher in the distal foci than in the ostial foci of PVs (43/121 vs 6/48, P = 0.04). The maximal amplitude of PV potential was significantly larger in the left PVs than in the right PVs, and the maximal duration of PV potential was significantly longer in the superior PVs than in the inferior PVs during sinus beats in both group I and II patients. CONCLUSION: PV electrogram characteristics were different among the four PVs. Detailed mapping and careful interpretation are the most important steps in ablation of paroxysmal AF originating from PVs.     

Pulmonary vein isolation for vagotonic, adrenergic, and random episodes of paroxysmal atrial fibrillation

INTRODUCTION: Based on the clinical history, paroxysmal atrial fibrillation (PAF) may be classified as vagotonic, adrenergic, or random. It is unclear whether pulmonary vein (PV) isolation is equally effective for these types of PAF. METHODS AND RESULTS: Segmental ostial ablation to isolate the PVs was performed in 188 consecutive patients (mean age 53 +/- 12 years) with PAF. Based on the clinical history, PAF was classified as random in 136 patients (72%), adrenergic in 30 (16%), and vagotonic in 22 (12%). Three or four PVs were targeted for isolation in all patients, and successful isolation was achieved in 96% of targeted PVs. At 1-year follow-up, 69% of patients with random AF, 83% of patients with adrenergic AF, and 50% of patients with vagotonic AF were free from recurrent episodes of AF in the absence of any antiarrhythmic drug therapy. Vagotonic AF was an independent clinical predictor of recurrent AF (P = 0.03). CONCLUSION: PV isolation has a lower efficacy in patients with vagotonic PAF than in patients with adrenergic or random episodes of PAF, suggesting that the PVs less often play an important role in vagotonic PAF.     

Discrimination of left atrial and pulmonary vein potentials in patients with paroxysmal atrial fibrillation

INTRODUCTION: Ablation of muscular fascicles around the ostium of pulmonary veins (PVs) resulting in electrical isolation of the veins may prove to be an effective treatment for atrial fibrillation (AF). Correctly discriminating atrial and PV potentials is necessary to effectively isolate PVs from the left atrium in patients with paroxysmal AF. METHODS AND RESULTS: A training set of 151 electrode recordings obtained from 10 patients with AF was used to develop an algorithm to discriminate atrial and PV potentials. Bipolar electrograms were collected from a multielectrode basket catheter placed sequentially into each PV. Amplitude, slope, and normalized slopes of both bipolar and quadripolar electrograms (difference between adjacent bipoles) were entered into a binary logistic regression model. A receiver operating characteristic curve was used to define a threshold able to effectively discriminate atrial and PV potentials. The normalized slopes of both domains, bipolar and quadripolar, produced a logistic function that discriminated atrial and PV potentials against a threshold (0.38) with 97.8% sensitivity and 94.9% specificity. The algorithm then was evaluated on a test set of 214 electrode recordings from four patients who also had paroxysmal AF. These patient electrograms also were evaluated by two independent electrophysiologists. The algorithm and electrophysiologists matched identification of activation origin in 84% of electrograms. CONCLUSION: Atrial and PV potentials acquired from a multielectrode basket catheter can be discriminated using the normalized slopes of bipolar and quadripolar electrograms. These additional parameters need to be included by physicians determining the preferential ablation site within PVs.     

Acquired pulmonary vein stenosis after radiofrequency catheter ablation of paroxysmal atrial fibrillation

INTRODUCTION: Elimination of the initiating focus within the pulmonary vein (PV) using radiofrequency (RF) catheter ablation is a new treatment modality for treatment of drug-refractory atrial fibrillation. However, information on the long-term safety of RF ablation within the PV is limited. METHODS AND RESULTS: In 102 patients with drug-refractory atrial fibrillation and at least one initiating focus from the PV, series transesophageal echocardiography was performed to monitor the effect of RF ablation on the PV. There were 66 foci in the right upper PV and 65 foci in the left upper PV. Within 3 days of ablation, 26 of the ablated right upper PVs (39%) had increased peak Doppler flow velocity (mean 130+/-28 cm/sec, range 106 to 220), and 15 of the ablated left upper PVs (23%) had increased peak Doppler flow velocity (mean 140+/-39 cm/sec, range 105 to 219). Seven patients had increased peak Doppler flow velocity in both upper PVs. No factor (including age, sex, site of ablation, number of RF pulses, pulse duration, and temperature) could predict PV stenosis after RF ablation. Three patients with stenosis of both upper PVs experienced mild dyspnea on exertion, but only one had mild increase of pulmonary pressure. There was no significant change of peak and mean flow velocity and of PV diameter in sequential follow-up studies up to 16 (209+/-94 days) months. CONCLUSION: Focal PV stenosis is observed frequently after RF catheter ablation applied within the vein, but usually is without clinical significance. However, ablation within multiple PVs might cause pulmonary hypertension and should be considered a limiting factor in this procedure.     

Substrate modification by pulmonary vein isolation and left atrial linear ablation in patients with persistent atrial fibrillation: its impact on complex-fractionated atrial electrograms

PV and Linear Ablation for CFAEs . Introduction: Linear ablations in the left atrium (LA), in addition to pulmonary vein (PV) isolation, have been demonstrated to be an effective ablation strategy in patients with persistent atrial fibrillation (PsAF). This study investigated the impact of LA linear ablation on the complex‐fractionated atrial electrograms (CFAEs) of PsAF patients. Methods and Results: A total of 40 consecutive PsAF patients (age: 54 ± 10 years, 39 males) who underwent catheter ablation were enrolled in this study. Linear ablation of both roofline between the right and left superior PVs and the mitral isthmus line joining from the mitral annulus to the left inferior PV were performed following PV isolation during AF. High‐density automated CFAE mapping was performed using the NAVX, and maps were obtained 3 times during the procedure (prior to ablation, after PV isolation, and after linear ablations) and were compared. PsAF was terminated by ablation in 13 of 40 patients. The mean total LA surface area and baseline CFAEs area were 120.8 ± 23.6 and 88.0 ± 23.5 cm² (74.2%), respectively. After PV isolation and linear ablations in the LA, the area of CFAEs area was reduced to 71.6 ± 22.6 cm² (58.7%) (P < 0.001) and 44.9 ± 23.0 cm² (39.2%) (P < 0.001), respectively. The LA linear ablations resulted in a significant reduction of the CFAEs area percentage in the region remote from ablation sites (from 56.3 ± 20.6 cm² (59.6%) to 40.4 ± 16.5 cm² (42.9%), P < 0.0001). Conclusion: Both PV isolation and LA linear ablations diminished the CFAEs in PsAF patients, suggesting substrate modification by PV and linear ablations. (J Cardiovasc Electrophysiol, Vol. 23, pp. 962‐970, September 2012)     

环肺静脉大环消融和肺静脉节段电隔离治疗阵发性心房颤动结果对比

目的 环肺静脉大环消融(CPVA)和肺静脉节段电隔离(SPVI)是目前导管射频消融治疗阵发性心房颤动(房颤)的两大主流术式,本文研究目的 是验证"CPVA对阵发性房颤的有效率比SP-VI高"这一假设,同时对比两种消融术式的其他治疗结果.方法 2006年1月至2007年12月入选阵发性房颤病人129例,SPVI和CPVA两组分别为64例和65例.排除标准为,房颤持续时间＞72 h,接受过导管消融的复发病例.结果 SPVI和CPVA组病人成功率分别为78.1%、78.5%;并发症发生率分别为7.8%、10.6%,差异无统计学意义.严重并发症3.9%.X线曝光时间SPVI组多于CPVA组,消融术时间CPVA组长于SPVI组.SPVI组的射频放电时间少于CPVA组.CPVA组术后房性心动过速/心房扑动发生率明显高于SPVI组(12.3%vs 3.1%).结论 SPVI和CPVA两种消融术式均能够比较安全有效地控制阵发性房颤的发作,治疗效果类似.     

Incidence and location of focal atrial fibrillation triggers in patients undergoing repeat pulmonary vein isolation: implications for ablation strategies

INTRODUCTION: The etiology of atrial fibrillation (AF) recurrences after pulmonary vein (PV) isolation is not well described. The aim of this study was to examine the reason for recurrent AF in patients undergoing a repeat attempt at AF trigger ablation. METHODS AND RESULTS: Patients with recurrent AF more than 1 month after ablation returned for repeat mapping and ablation. A circular mapping catheter was advanced to each previously targeted PV ostium to determine if the PV was still electrically isolated. Ectopy then was provoked with isoproterenol (up to 20 microg/min), burst pacing, and pacing into AF followed by cardioversion. The location of ectopy triggering atrial premature depolarizations (APDs) or AF was noted. Of 226 patients who underwent ablation of AF triggers, 34 (8 women and 26 men; age 56 +/- 10 years) with recurrent AF returned for a repeat procedure 207 +/- 183 days after the first procedure. There were 84 previously completely isolated PVs in these 34 patients. Thirty-three (39%) of 84 previously isolated PVs were still completely isolated at the time of the second procedure. Fifty-one PVs (61%) had evidence of recovered PV potentials. Fifty triggers of APDs and AF (n = 30) or APDs only (n = 20) were identified in these 34 patients. The majority of triggers [27/50 (54%)] originated from previously targeted PVs. Sixteen triggers [16/50 (32%)] originated from previously nontargeted PVs. CONCLUSION: The majority of AF recurrences originate from previously isolated PVs. One third of recurrent triggers originated from PVs that were not targeted during the initial ablation session. Although empiric isolation of all PVs may reduce recurrences, strategies to ensure ostial PV isolation and to prevent recurrent PV conduction after ablation should have the greatest impact on reducing AF recurrence.     

EnSite NavX指导下无肺静脉造影的阵发性心房颤动导管消融术

目的探讨不作肺静脉造影行阵发性心房颤动(房颤)环肺静脉电隔离术的有效性和可行性。方法 34例阵发性房颤患者分为无肺静脉造影组(n=18)和肺静脉造影组(n=16),无肺静脉造影组不作肺静脉造影,余步骤与肺静脉造影组相同,两组均在EnSiteNavX三维标测系统指导下重建左心房及肺静脉,再分别行左、右环肺静脉电隔离术,消融终点为肺静脉与心房完全电隔离。结果无肺静脉造影组消融术时间[(92.78±19.46)minvs.(106.44±20.18)min,P0.05]及X-线曝光时间[(11.47±4.32)minvs.(16.06±8.72)min,P0.05]少于肺静脉造影组,差异有统计学意义。两组左心房三维重建时间[(6.22±2.65)minvs.(6.31±3.00)min,P0.05]、左、右侧环肺静脉消融时间[(21.61±7.66)minvs.(20.50±8.09)min,P0.05;(17.33±10.22)minvs.(17.48±7.86)min,P0.05]及即刻消融成功率[100%(18/18)vs.100%(16/16),P0.05]比较,差异无统计学意义。结论不作肺静脉造影,仅在三维标测系统指导下行房颤消融治疗,可达到相同消融效果,可节省消融术及X-线曝光时间,减少手术步骤、耗材和费用。     

射频导管消融电学隔离心脏大静脉治疗阵发性心房颤动的临床应用

目的评价射频导管消融电学隔离心脏大静脉预防阵发性心房颤动(房颤)发作的疗效。方法83例患者,男性58例、女性25例,年龄15～76平均(605±185)岁,有阵发性房颤病史2～15年,曾服数种抗心律失常药物疗效不佳。41例患者合并有高血压病,所有患者均无明显器质性心脏病改变。常规行心脏大静脉造影,测量靶静脉直径,将10极肺静脉环状标测导管(Lasso导管)放置在靶静脉开口内05cm处,以Lasso导管为指导,把温控大头电极导管放置于靶静脉开口处行电学隔离。结果83例患者共电学隔离大静脉343条。包括左上肺静脉(LSPV)83条,右上肺静脉(RSPV)83条,左下肺静脉(LIPV)82条,右下肺静脉(RIPV)42条,上腔静脉(SVC)53条,其中2例LSPV与LIPV共同开口。每条肺静脉行1～4段消融(平均每条消融25段),即刻电学隔离成功大静脉337条。随访2～31个月,其中50例停服抗心律失常药物后无房颤发生,13例患者房颤发作明显减少,20例患者房颤发作消融前后无明显变化。并发症有2例术中出现左侧大量胸腔积血,1例心肺复苏5天后出现脑死亡。发现肺静脉狭窄21例,其中轻度狭窄15例,重度狭窄6例,无肺静脉闭塞。结论(1)成功的心脏大静脉电学隔离治疗阵发性房颤的总有效率达到75%左右;(2)由于很难确定靶肺静脉,成功电学隔离各心脏大静脉有可能提高治愈率;(3)此     

Preprocedural predictors of atrial fibrillation recurrence following pulmonary vein antrum isolation in patients with paroxysmal atrial fibrillation: long-term follow-up results

Predictors of Recurrence after AF Ablation. Introduction: The objective of this study was to identify the simple preprocedural parameters of atrial fibrillation (AF) recurrence following single ablation procedure in patients with paroxysmal AF during long‐term follow‐up period. Methods and Results: Consecutive 474 patients (61 ± 10 years; 364 males, left atrial (LA) diameter 37.6 ± 5.1 mm) with drug‐refractory paroxysmal AF who underwent AF ablation were analyzed. Pulmonary vein antrum isolation (PVAI), cavotricuspid isthmus line creation with bidirectional conduction block, and elimination of all non‐PV triggers of AF were performed in all patients. With a mean follow‐up of 30 ± 13 months after single procedure, 318 patients (67.1%) were in sinus rhythm without any antiarrhythmic drugs. Multivariate analysis using Cox's proportional hazards model, including the age, gender, duration of AF, body mass index, LA size, left ventricular ejection fraction, and presence of hypertension and structural heart disease as variables, demonstrated that LA size was an independent predictor of AF recurrences after PVAI with a 7.2% increase in the probability for every 1 mm increase in LA diameter (P = 0.0007). When the patients were categorized into 3 groups according to the LA diameter, the patients with moderate (40–50 mm) and severe dilatation (>50 mm) had a 1.30‐fold (P = 0.0131) and 2.14‐fold (P = 0.0057) increase, respectively, in the probability of recurrent AF as compared with the patients with normal LA diameter (≤40 mm). Conclusion : In the long‐term follow‐up period, LA size was the best preprocedural predictor of AF recurrence following single ablation procedure in the patients with paroxysmal AF, even in the patients with a relatively small LA. (J Cardiovasc Electrophysiol, Vol. 22, pp. 621‐625, June 2011)     

Percutaneous pulmonary vein isolation for treatment of atrial fibrillation

BACKGROUND: Transvenous catheter ablation for the treatment of atrial fibrillation is an evolving technique. AIM: The purpose of this study was to identify subgroups of patients most likely to benefit from pulmonary vein electrical isolation. METHODS: Patients with symptomatic atrial fibrillation resistant to pharmacological therapy were studied. Mapping-guided segmental application of radio-frequency energy was used to electrically isolate the pulmonary veins in 74 patients. Ischaemic or dilated cardiomyopathy was present in 34% of patients. Atrial fibrillation had been present for a mean time (+/- standard deviation) of 6.6 +/- 6.1 years. It was paroxysmal in 53 patients (72%). RESULTS: The mean number of procedures was 1.6/patient. After 6 +/- 6 months, 73% of patients (54/74) were in sinus rhythm. Thirteen of those in sinus rhythm were using anti-arrhythmic medications (25%). Recurrence of atrial fibrillation soon after pulmonary vein isolation occurred in 50%. Patients with persistent/permanent atrial fibrillation were less likely to be in sinus rhythm at follow up (11/21 (52%) vs 43/53 (81%); P = 0.01). However, the rate of early recurrence was similar in the intermittent and the persistent/permanent groups (26/53 (49%) vs 11/21(52%), respectively; P-value not significant). Patients with persistent atrial fibrillation were more likely to experience a recurrence of atrial fibril-lation (89%; P = 0.04). No other baseline factors predicted procedural success. Cardiac tamponade occurred in two patients and moderate pulmonary vein stenosis (>50% diameter narrowing) occurred in three patients. CONCLUSIONS: Pulmonary vein isolation is an effective curative treatment for a broad group of patients with atrial fibrillation. However, the procedure is only suitable for patients with problematic atrial fibrillation resistant to other therapies because of the small risk of serious complications.     

应用盐水灌注消融导管进行肺静脉-心房电隔离治疗阵发性心房颤动

目的探讨应用盐水灌注消融导管对肺静脉-心房(PV-LA)电隔离治疗阵发性心房颤动(房颤)的效果.方法26例患者,男性22例,女性4例,年龄31～69(52±11)岁,均有阵发性房颤病史.患者分为2组,第1组15例应用普通4 mm电极温控导管消融,第2组11例应用盐水灌注导管消融.所有患者均在环状标测电极导管指导下行3根或4根肺静脉(PV)消融.结果第1组15例患者第1次消融了50根PV,即刻PV-LA电隔离成功率92%,手术时间平均3.5 h.其中在2例因房颤复发行第2次消融的患者中,第1次消融的7根PV中有6根(86%)恢复了与LA间的传导.第1组随访平均13个月,无房颤发作者8例(53%,含2例经再次消融患者),有效3例(20%).第2组11例患者第1次消融了44根PV,即刻PV-LA电隔离成功44根,成功率100%,11例手术时间平均2.8 h,1例应用盐水灌注消融导管消融时发生心脏压塞.第2组随访平均4个月,无房颤发作者7例(64%),有效2例(18%).结论应用盐水灌注消融导管进行PV-LA电隔离可能(1)缩短PV-LA电隔离所需的时间和提高成功率;(2)减少术后PV-LA电传导恢复的可能性,从而减少复发率;(3)初步结果表明应用盐水灌注消融导管较安全,但是否增加PV狭窄和心脏压塞等并发症尚需进一步的资料.     

Radiofrequency catheter ablation of atrial fibrillation initiated by pulmonary vein ectopic beats

Ectopic beats from the pulmonary veins (PVs) have been demonstrated to initiate atrial fibrillation (AF). This article describes the conceptual approach to mapping, interpretation of different electrograms, and ablation of AF initiated by PV ectopic beats.     

Electrophysiologically guided pulmonary vein isolation during sustained atrial fibrillation

INTRODUCTION: Sustained atrial fibrillation (AF) is frequently encountered during pulmonary vein (PV) isolation. The aim of this study was to evaluate the feasibility and safety of PV isolation during sustained AF. METHODS AND RESULTS: Thirty-seven patients (30 men, age 54 +/- 10 years) underwent Lasso-guided isolation of 87 PVs during sustained AF. Baseline PV electrogram patterns were classified into one of two types: organized, with consistent PV activation sequence; or disorganized, with constant variation of PV activation sequence. In disorganized activity, radiofrequency ablation was performed circumferentially around the Lasso while the earliest PV potential was targeted during organized activity. Complete left atrial (LA) to PV block during AF was identified by abolition or dissociation of all sharp potentials recorded within the vein. PV isolation then was verified during sinus rhythm. Baseline activation patterns of PV potential were organized in 32 PVs (37%) [more frequently in inferior veins than superior veins (53% vs 26%, P = 0.01)] and disorganized in 55 PVs (63%). In 59 of 87 PVs, isolation was begun and completed during AF. Radiofrequency ablation organized PV activation sequence in 75% prior to isolation. LA-PV block was confirmed during sinus rhythm in 54 (92%) of 59 PVs. In 28 of 87 PVs, sinus rhythm was restored before complete LA-PV block. Complete isolation was achieved in all 87 PVs without complications. CONCLUSION: PV isolation can be effectively and safely performed during sustained AF, preceded in most cases by organization of PV electrogram activity. This strategy may be the preferred alternative to multiple intraprocedural cardioversions.     

Modified Maze lines plus pulmonary vein isolation created by radiofrequency catheter ablation on the atrial wall to treat atrial fibrillation in elderly

Objective To evaluate the effect of modified Maze lines plus pulmonary vein (PV) isolation created by radiofrequency catheter ablation (RFCA) on atrial wall guided by a novel geometry mapping system in the treatment of elderly patients with paroxysmal atrial fibrillation (PAF). Methods After regular electrophysiological study, transseptal punctures were achieved twice with Swartz L1 and R1 sheaths. PV angiographics were conducted to evaluate their orifices and branches. A balloon electrode array catheter with 64 electrodes was put in the middle of the left atrium. Atrium geometry was constructed using Ensite 3000 Navx system. Two RFCA lesion loops and three lines (modified Maze) were created on left and right atrial walls. Each lesion point was ablated for 30 seconds with preset temperature 50 (?)and energy 30W. The disappearance or 80% decrease of the amplitude of target atrial potential and 10 to 20. decrease of ablation impedance were used as an index of effective ablation. Results A total of 11 patients (7 male and 4 female, mean age, 68.7±5.1 years) were enrolled. PAF history was 7.9±4.5 years. PAF could not be prevented by mean 3.1±1.6 antiarrhythmic agents in 6.3±3.4 years. None of the patients had complications with structural heart disease or stroke. Left atrial diameter was 41.3±3.6 mm and LVEF was 59.2±3.7 % on echocardiography. Two loops and three lines were completed with 67.8±13.1 (73-167) lesion points. Altogether 76-168 (89.4±15.3) lesion points were created in each patient. PAF could not be provoked by rapid burst pacing up to 600 beat per minute delivered from paroxysmal coronary sinus electrode pair. Complete PV electrical isolation was confirmed by three-dimensional activation mapping. Mean procedure time was 2.7±0.6 hours and fluoroscopy time was 17.8±9.4 minutes. Patients were discharged with oral aspirin and without antiarrhythmic agents. During follow up of 6.5±1.8 months, seven patients were PAF symptom free (63.6%). PAF attacks were decreased more than 70% in two patients (18.2%). PAF frequency did not change in another two patients (18.2%). Conclusions Ensile 3000 Navx guided modified Maze lines plus PV isolation on the atrial wall is safe and feasible in the elderly palienls. It has the advanlages of exact procedural endpoint, shorter X-ray exposure, fewer complications and salisfied long-term effect PAF control. (J Geriatr Cardiol 2005;2(2): 95-100).     

Clinical outcome of very late recurrence of atrial fibrillation after catheter ablation of paroxysmal atrial fibrillation

INTRODUCTION: High recurrence rate is still a major problem associated with ablation of paroxysmal atrial fibrillation (AF). Most of the recurrences occur within 6 months after ablation. The characteristics of very late recurrent AF (>12 months after ablation) have not been reported. METHODS AND RESULTS: Two hundred seven patients with drug-refractory AF underwent successful focal ablation or isolation of AF foci. After the first ablation procedure, Holter monitoring and event recorders were used to evaluate symptomatic recurrent AF. A second ablation procedure was recommended if the antiarrhythmic drugs could not control recurrent AF. During long-term follow-up (mean 30 +/- 11 months, up to 51 months), 70 patients had recurrent AF, including 13 patients (6%) with very late (>12 months) recurrent AF (group 1) and 57 patients (28%) with late (within 12 months after ablation) recurrent AF (group 2). Group 1 patients had a significantly lower incidence of multiple (> or = 2) AF foci (23% vs 63%, P = 0.02) than group 2 patients. In addition, the incidence of antiarrhythmic drugs use (38% vs 84%, P = 0.001) to maintain sinus rhythm after the first episode of recurrent AF was significantly lower in group 1 than group 2 patients, and the incidence of a second intervention procedure (8% vs 35%, P = 0.051) tended to be lower in group 1 than group 2 patients. CONCLUSION: The incidence of very late recurrent AF after ablation of paroxysmal AF is very low, and the clinical outcome of patients with very late recurrent AF is benign.