Pulmonary vein isolation for atrial fibrillation in patients with paroxysmal atrial fibrillation and prolonged sinus pause

BACKGROUND: Symptomatic prolonged sinus pauses upon termination of atrial fibrillation (AF) are an indication for pacemaker implantation. METHODS AND RESULTS: We evaluated the clinical outcomes of 4 patients who showed prolonged sinus pauses (> 2 seconds) upon termination of AF and thus underwent ablation. The ablative procedure included pulmonary vein isolation, superior vena cava isolation, and cavo-tricuspid isthmus ablation. Twenty-four-hour ambulatory electro-cardiogram monitoring was performed before and 1 month after ablation. The maximum sinus pause decreased from 4.5 +/- 2.1 seconds before ablation to 1.7 +/- 0.2 seconds after ablation. Sinus pauses > 2.0 seconds disappeared after ablation in all 4 patients. Minimum heart rate increased from 35.0 +/- 8.1 beats/minute before ablation to 52 +/- 6.7 beats/minute after ablation. The number of heart beats in 24 hours did not change significantly after ablation. CONCLUSION: Prolonged sinus pauses after paroxysmal AF may result from depressed sinus node function, which can be eliminated by curative ablation of AF.     

Pulmonary vein dilation in patients with atrial fibrillation: detection by magnetic resonance imaging

INTRODUCTION: The positive relationship between left atrial (LA) size and atrial fibrillation (AF) is well recognized; however, there is little information on the association of pulmonary vein (PV) diameter and AF. The purpose of this study was to investigate by magnetic resonance angiography the change of PV and LA size in patients with no history of AF, patients with paroxysmal AF (PAF), and patients with chronic AF (CAF). METHODS AND RESULTS: The study included 47 patients. Group I included 15 patients with normal sinus rhythm and no history of documented AF. Group II included 24 patients with drug-refractory PAF who underwent electrophysiologic study and radiofrequency ablation of PV foci. Group III included 8 patients with CAF who were converted to sinus rhythm by external electrical cardioversion. Age and concomitant heart diseases were similar among the three groups. We measured the diameter of each PV at its junction with the LA in addition to LA dimensions by gadolinium-enhanced magnetic resonance angiography with three-dimensional reconstruction. Significant dilation of both superior PVs (P < 0.01) and transverse diameter of LA (P < 0.01) was seen in the three groups. There were no significant changes of both inferior PVs, corrected PV (PV/LA) diameter, or longitudinal diameter of LA among the three groups. Only 28% patients showed arrhythmogenic foci from the largest PV. CONCLUSION: Significant dilation of both superior PVs with simultaneous LA enlargement was demonstrated i     

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.     

Analysis of the left atrial appendage by magnetic resonance angiography in patients with atrial fibrillation

BACKGROUND: Recent interest has focused on the left atrial appendage (LAA) in the setting of atrial fibrillation as a potential source of thromboembolism and stroke, which may be amenable to permanent occlusion by a variety of investigational catheter-delivered devices. Precise anatomic characterization of the LAA is necessary to determine the suitability of a patient for device placement and for device selection and sizing. OBJECTIVES: The purpose of this study was to perform detailed three-dimensional characterization of LAA size and geometry by magnetic resonance angiography. METHODS: Fifty patients with chronic atrial fibrillation undergoing cardiac magnetic resonance angiography in preparation for catheter ablation of atrial fibrillation were analyzed for LAA volume, neck size, depth, and overall geometry. RESULTS: The average LAA volume was 17.3 +/- 6.7 mL, with a depth of 26.6 +/- 4.9 mm and a "neck" diameter of 20.0 +/- 5.3 mm x 14.1 +/- 4.7 mm. The average number of LAA lobes was 1.4 +/- 0.7 (range 1-4). Substantial interpatient variability was present in the relative dimensions and morphology of the LAA. There was a significant correlation between left atrial size and LAA neck dimensions. CONCLUSION: There is significant heterogeneity in LAA size and dimensions among patients with atrial fibrillation. Device occlusion of the LAA may require devices that are available in multiple sizes/shapes or that can adapt to this heterogeneity.     

Pulmonary vein isolation using segmental versus electroanatomical circumferential ablation for paroxysmal atrial fibrillation

PURPOSE: We tested the hypothesis that electroanatomic pulmonary vein (PV) antra encircling for the PV isolation will improve the outcome in treatment of paroxysmal atrial fibrillation (PAF), compared with segmental PV isolation. METHODS: Fifty-four patients underwent segmental PV isolation (group 1) and 56 patients circumferential PV isolation (group 2) for symptomatic PAF in a randomized study. RESULTS: Following single ablation procedure, at the 48 +/- 8 month follow-up, 30 (56%) and 32 (57%) patients in groups 1 and 2 remained free of arrhythmia (P = 0.41). After repeat ablation, 43 (80%) and 45 (80%) patients in groups 1 and 2 were free of arrhythmia without antiarrhythmic drugs (AADs); 48 (89%) and 51 (91%) patients in groups 1 and 2 did not have arrhythmia recurrences without or with AADs. CONCLUSION: This study demonstrates no advantage in long-term arrhythmia-free clinical outcome after circumferential PV isolation in patients with frequent PAF.     

阵发性心房颤动患者非肺静脉触发灶的诱发及消融

目的探讨环肺静脉电隔离（CPVI）术中静脉注射异丙肾上腺素（ISO）和三磷酸腺苷：ATP）,在检出阵发性心房颤动（房颤）非肺静脉触发灶中的价值。方法回顾性分析2010年4～12月色浙江邵逸夫医院心内科所有患者接受三维标测系统指导下CPVI术136例患者,其中87例消融前后分别应用ISO＋ATP诱发房颤,Lasso导管置于右上肺静脉口、消融导管置于左上肺静脉中,结合冠状静冰窦导管判断房颤的触发灶,然后通过消融验证。结果87例首次接受导管消融的阵发性房颤患者,吏用ISO＋ATP后16例证实有非肺静脉房颤触发灶。其中,消融前诱发8例房颤、1例房性心动过速（房塞）、1例频发房性早搏（房早）。2例消融前诱发的患者CPVI术后房性快速性心律失常（ATa）仍存在,余8例及5例消融前未被诱发者CPVI后再次诱发时又检出非肺静脉触发灶。其中,9例为房颤（起源上腔静脉5例、冠状静脉窦内靠近口部1例、左心房后壁2例、不明1例）,3例房性心动过速（均为冠状挣脉窦口起源）和1例频发房性早搏（上腔静脉起源）。14例患者在相应非肺静脉触发灶部位消融后心聿失常均终止,且不再被诱发。2例起源不明的房颤患者电复律后转为窦性心律。随访2年,单次手术或功率为87．5％（14／16）。结论静脉注射ISO＋ATP可简单有效地检出阵发性房颤非肺静脉触发灶。     

射频消融肺静脉电隔离术治疗阵发性房颤20例

目的观察电生理标测指导下肺静脉电隔离术治疗阵发性房颤的临床疗效.方法阵发性房颤患者20例,环状电极指示下对肺静脉行射频消融电隔离术.结果20例患者共接受心脏大静脉电隔离治疗28次(6例进行了第2次,1例进行了第3次),隔离静脉68根,肺静脉62根,上腔静脉6根,在房颤心律下消融58根,62根肺静脉中54根达到消触终点.平均操作时间和X线透视时间分别为(120±18)min和(32±9)min.平均随访(5.0±2.3)个月,示13例无房颤发作、2例房颤发作明显减少,总有效率达75%.结论肺静脉电隔离术治疗阵发性房颤具有较好临床疗效.     

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.     

Pulmonary vein isolation in patients with paroxysmal atrial fibrillation after direct suture closure of congenital atrial septal defect.

Two cases of paroxysmal atrial fibrillation (AF) first occurred 15 and 36 years, respectively, after isolated direct suture closure of an atrial septal defect (ASD) and failed to be controlled by antiarrhythmic drug therapy. In these cases, an atrial transseptal procedure was feasible and no residual iatrogenic ASD was observed, even after multiple procedures. Pulmonary vein (PV) isolation was also feasible and safe and could eliminate the AF completely. PV isolation may become an alternative to antiarrhythmic drug therapy in patients with paroxysmal AF occurring late after an isolated direct suture closure of an ASD.     

阵发性心房颤动患者肺静脉前庭电生理现象及分析

目的采用EnSite/NavX系统指导下,结合单Lasso进行环肺静脉电隔离术治疗阵发性心房颤动(简称房颤),分析消融过程中肺静脉前庭电生理现象。方法入选2004年10月~2005年12月症状性阵发性房颤患者143例,男85例、女58例,年龄60.7±10.3(35~80)岁,房颤病程5.5±6.7年(21天~50年),左房内径36.9±6.4(24~54)mm。在EnSite-NavX系统引导下行环肺静脉消融达到肺静脉电隔离。结果143例完成环肺静脉隔离术,手术时间157±30(90~240)min,放射线时间25.8±8.8(9.8~60.1)min。环单侧左、右肺静脉前庭消融电隔离率分别为81.2%、78.3%,其余病例结合节段性消融(SOA)达到肺静脉电隔离。房颤终止的比例为69.7%(23/33例),第一次消融63.6%(91/143)可记录到肺静脉内自发电位,2.1%(3/143)可记录到肺静脉内快速的自主节律,而体表心电图为稳定的窦性心律。房颤复发患者第二次消融时,所有21例均有肺静脉电位(PVP)恢复,其中第一次消融时结合SOA达到肺静脉隔离的患者:57.1%左侧PVP恢复,55.6%右侧PVP恢复。第二次消融时,85.7%(18/21)例存在肺静脉内自发电位。术后房性心动过速/心房扑动15例(10.5%),12例再次行射频消融治疗,11例消融成功。术后随访10.7±4.9(4~18)个月,包括第二次消融术后患者在内,共90.2%(129/143)在无抗心律失常药物治疗下无房颤发作。心包积液2例,Ensite/NavX电极贴片故障1例。结论心房-肺静脉传导存在优势传导径路,且传导方式并非“全或无”;结合SOA的消融方法复发率较高;多数患者肺静脉隔离后可记录到自发肺静脉电位,复发患者的肺静脉通常具有较高的兴奋性。     

阵发性心房颤动的昼夜分布节律

目的　观察阵发性心房颤动（房颤）的昼夜分布节律。方法　对阵发房颤的患者进行２４ ｈ动态心电图及持续心电图监测观察其起始、持续和终止的节律变化。结果　３２ 例孤立性阵发性房颤的起始高峰时间４３ 阵（４６．７％ ）发生在午夜至清晨６时。１９ 阵（２０．７％ ）发生在上午６∶００～１２∶００ 时，２１阵（２２．８％ ）发生在１２∶００～１８∶００ 时，９阵（９．８％ ）发生在１８ 时～午夜。持续时间为凌晨４ 时至上午１１时，终止时间为中午及下午。结论　阵发性房颤昼夜分布节律与自主神经及内源性生物活性物质的节律变化有关     

肺静脉节段性消融治疗阵发性心房颤动

肺静脉内的折返是促使心房颤动（房颤）发作的最可能机制，肺静脉在房颤的发生和维持机制中起重要作用。在实时左心房三维标测系统（Carto）指导下，肺静脉环状射频消融电隔离治疗阵发性房颤已成为可能。这里我们评价术前16排螺旋CT指导下肺静脉节段性消融治疗顽固性阵发性房颤的临床效果。     

阵发性心房颤动患者肺静脉前庭心内膜电位的特点分析

目的探讨阵发性心房颤动(简称房颤)患者肺静脉前庭(PVA)区域心内膜电位的特点。方法在三维电解剖标测系统指导下,结合CT影像融合,对25例阵发性症状性房颤患者进行环肺静脉前庭消融术(CPVA)。术中对PVA部位进行标测,记录并分析PVA电位特点。结果环绕双侧PVA各取100个位点,发现右侧PVA取样点中有42个位点为宽时程(≥50 ms)的双峰电位(DP),41个位点为碎裂电位(CFAE),17个位点为单电位(SP)或窄时程(<50 ms)DP。左侧取样点中38个为DP,48个位点为CFAE,14个位点为SP。双侧PVA区域心内膜电位均以DP或CFAE为主(占84.5%),只有少数区域(15.5%)为SP;环PVA区域不同部位之间电位分布无差异(P>0.05)。结论PVA区域心内膜电位多表现为DP或CFAE,在PVA区域寻找这种缓慢的电传导部位,可能有助于PVA的组织学定位。