心房颤动消融术后二尖瓣峡部房性心动过速的发生机制及消融治疗

目的探讨心房颤动(简称房颤)患者环肺静脉左房线性消融术后二尖瓣峡部房性心动过速(简称房速)的发生机制及其消融策略。方法122例房颤患者采用EnSite-NavX和环状电极行环肺静脉左房线性消融,术后32例复发房颤或房速,8例经EnSite-NavX激动标测及拖带标测证实存在二尖瓣峡部房速,在三维导航下于左下肺静脉口部下缘至二尖瓣环之间行线性消融,对不能成功阻断二尖瓣峡部传导者予以冠状静脉窦内消融。术中同时探查双侧肺静脉电位,如传导恢复予以再次隔离。结果8例中2例呈无休止性发作,6例为阵发性,可被程序刺激诱发。房速的周长217.5±20.6ms,其中顺钟向折返5例,逆钟向折返3例。二尖瓣峡部线性消融至完全性双向传导阻滞5例,3例心内膜途径失败者经冠状静脉窦内消融,其中1例获得成功。术后随访5.5±4.3个月,6例无房颤及房速发作,1例仍有阵发性房速发作。另1例术后房速呈无休止发作,予以胺碘酮及美托洛尔控制心室率治疗。结论环肺静脉线性消融术后发生的二尖瓣峡部房速与左房线性消融治疗房颤的致心律失常作用有关,其主要的机制是消融线相关的大折返性心动过速,阻断峡部传导可以治疗此类房速。     

导管射频消融治疗持续性心房颤动的体会

目的研究持续性心房颤动(房颤)导管射频消融最佳手术方式及复发心律失常的处理策略。方法2005年3月~2007年8月共40例持续性房颤患者接受导管射频消融治疗,三维电解剖标测系统指导下行环同侧肺静脉左心房线性消融;2005年的12例患者部分附加左心房峡部、右心房峡部、左心房顶部线性消融;2006年的12例患者常规进行左心房峡部、右心房峡部射频消融,部分患者附加碎裂电位、左心耳或根据术中的房性心律失常附加其他部位射频消融;2007年的16例患者则在上述基础上进行冠状窦左心房心内膜面射频消融。结果2005年复发8例(66.7%),2006年复发3例(25.0%),2007年复发4例(25.0%)。复发的患者中8例接受第二次导管射频消融术,其中5例维持窦性心律。平均随访(17.6±10.4)个月,总治疗成功率82.5%。结论持续性房颤患者在以肺静脉口为核心的导管射频消融前提下,适当改进导管射频消融策略,可以显著提高成功率。     

递进式消融法治疗持续性心房颤动的初步体会

目的评价一种递进式消融法治疗持续性心房颤动（房颤）的疗效。方法34例持续性房颤患者,年龄（54．8±11．4）岁,病程（36．5±9．8）个月。按以下顺序进行递进式消融：环肺静脉前庭消融达肺静脉电学隔离,左心房顶部和二尖瓣环峡部线性消融,心房碎裂电位消融,针对房颤转变的心房扑动（房扑）／房性心动过速（房速）行Carto激动标测结合拖带技术以明确其机制,并力求通过消融终止。结果递进式消融法使88．2％患者房颤节律发生变化（直接终止或转变为房扑／房速）,61．8％直接通过消融恢复窦性心律。随访（12．6±6．2）个月,82．4％患者维持窦性心律（其中42．9％服用胺碘酮）。结论递进式消融是治疗持续性房颤的一种有效方案。     

Mini-maze suffices as adjunct to mitral valve surgery in patients with preoperative atrial fibrillation

INTRODUCTION: After mitral valve (MV) surgery, preoperative atrial fibrillation (AF) often recurs while cardioversion therapy generally fails. Additional Cox maze surgery improves postoperative arrhythmia outcome, but the extensive nature of such an approach limits general appliance. We investigated the clinical outcome of a simplified, less extensive Cox maze procedure ("mini-maze") as adjunct to MV surgery. METHODS AND RESULTS: Thirteen patients with MV disease and preoperative AF were treated with combined surgery (group 1). Nine control patients without previous AF underwent isolated MV surgery (group 2). We retrospectively compared the results to findings in 23 patients with preoperative AF who had undergone isolated MV surgery (group 3). In group 1, mini-maze took an additional 46 minutes of perfusion time. One 75-year-old patient died of postoperative multiple organ failure. Seven patients showed spontaneously converting (within 2 months) postoperative AF. After 1 year, 82% were in sinus rhythm (SR). No sinus node dysfunction was observed. In group 2, all patients were in SR after 1 year. In group 3, only 53% were in SR after 1 year, despite serial cardioversion and antiarrhythmic drug therapy. Exercise tolerance and heart rate were comparable for groups 1 and 2. Left atrial function was present in all but one patient in group 1 and in all patients in group 2 (after MV reconstruction). CONCLUSION: Adding a relatively simple mini-maze to MV surgery improves arrhythmia outcome in patients with preoperative AF without introducing sinus node dysfunction or persistent absence of left atrial function. The results of this type of combined surgery are encouraging and deserve further attention.     

Stepwise linear approach to catheter ablation of atrial fibrillation

BACKGROUND: This study attempted to convert atrial fibrillation (AF) to sinus rhythm using a stepwise linear catheter ablation approach. METHODS: One hundred and ninety-six patients (43 with persistent AF) were enrolled in the study. A multiple electrode array was used for anatomical navigation and activation mapping. Continuously incremental stimulation was used to induce AF if spontaneous AF was not present. Stepwise linear ablation was applied until AF was converted to sinus rhythm or atypical atrial flutter (AAFL) or atrial tachycardia (AT). The stepwise approach initially utilized a figure-7 lesion line between the right and left superior pulmonary vein on the roof of the left atrium and then extended along the ridge between the left appendage and the left pulmonary veins until the mitral valve annulus, as the primary lesions. If AF still persisted, high-frequency potentials in the inferior left atrium, coronary sinus, or right atrium were targeted. Noninducibility of AF was used as the end point. RESULTS: AF was converted to sinus rhythm in 81.6% of patients (90.8% of paroxysmal and 51.1% of persistent AF, P<.01). The remainders of patients were converted to AAFL or AT. AF was terminated after ablation in right atrium in 7 patients. During an 18.2+/-7.3 month follow-up, 88.3% of patients were free of atrial tachyarrhythmias without medication, 9.7% of patients had refractory AAFL/AT, and only 2.1% of patients had paroxysmal AF. CONCLUSION: Stepwise linear ablation is effective in converting AF to sinus rhythm and the figure-7 lesion line should be the basic lesion. Right atrium ablation is necessary in some patients.     

Catheter ablation of long-lasting persistent atrial fibrillation: clinical outcome and mechanisms of subsequent arrhythmias

BACKGROUND: Catheter ablation of atrial fibrillation (AF) is challenging in patients with long-standing persistent AF. The clinical outcome and subsequent arrhythmia recurrence after using an ablation method targeting multiple left atrial sites with the aim of achieving acute AF termination has not been characterized. METHODS: Sixty patients (mean age: 53 +/- 9 years) with persistent AF (mean duration: 17 +/- 27 months) were prospectively followed after catheter ablation. Catheter ablation targeting the following sites was performed in a random sequence: (i) electrical isolation of all pulmonary veins (PV); (ii) disconnection of other thoracic veins; (iii) atrial ablation at sites possessing complex electrical activity, activation gradients, or short cycle lengths. Finally, linear ablation of the LA roof and mitral isthmus was performed if sinus rhythm was not restored following energy delivery to the above sites. At 1, 3, 6, and 12 months after ablation, patients underwent clinical review and 24-hour ambulatory ECG monitoring to identify asymptomatic arrhythmia. Repeat mapping and catheter ablation was performed in any patient experiencing recurrent atrial tachycardia (AT). Clinical success was defined as the absence of any sustained atrial arrhythmia. RESULTS: AF terminated during ablation in 52 patients (87%). The fluoroscopy and procedural durations were 84 +/- 30 minutes and 264 +/- 77 minutes, respectively. Three months after ablation, sustained ATs were documented in 24 patients (associated with AF in 2). Mapping in 23 patients showed a single AT in 7 while multiple ATs were observed in 16. Macroreentry was confirmed to be due to gaps in the ablation lines, while focal ATs originated from discrete sites or isthmuses near the left atrial appendage, coronary sinus, pulmonary veins, or fossa ovalis; these sites were similar to those at which the greatest impact was observed on the fibrillatory process during the initial ablation procedure. After repeat ablation, at 11 +/- 6 months of follow-up, 57 patients (95%) were in sinus rhythm and 3 developed recurrent AF or AT. All patients in sinus rhythm demonstrated improved exercise capacity and all but 2 had evidence of atrial transport as assessed by Doppler echocardiography (mitral A wave velocity 34 +/- 17 cm/sec) by 6 months. CONCLUSION: Catheter ablation of long-lasting persistent AF associated with acute AF termination achieves medium to long-term restoration and maintenance of sinus rhythm in 95% of patients. Arrhythmia recurrence in the majority of patients is AT.     

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。     

Electrophysiological Characteristics of Localized Reentrant Atrial Tachycardia Occurring After Catheter Ablation of Long-Lasting Persistent Atrial Fibrillation

Background: Mapping of recurrent atrial tachycardia (AT) after extensive ablation for long-lasting persistent atrial fibrillation (AF) is complex. We sought to describe the electrophysiological characteristics of localized reentry occurring after ablation of long-lasting persistent AF.
Methods: Out of 70 patients undergoing catheter ablation of long-lasting persistent AF, 9 patients (13%, 55 ± 8 years, 8 males) in whom localized reentry was demonstrated in a repeat ablation were studied. Localized reentry was defined as reentry in which the circuit was localized to a small area and did not have a central obstacle. The mechanism of AT was determined by electroanatomical and entrainment mapping.
Results: Nine localized reentries with cycle length of 243 ± 41 ms were mapped in 9 patients. The location of AT was the left atrial appendage in 4 patients, anterior left atrium in 2, left septum in 2, and mitral isthmus in 1. In all ATs, a critical isthmus of <10 mm in width was identified in the vicinity of the prior linear lesions or ostia of isolated pulmonary veins. Ablation of the critical isthmus, which was characterized by continuous low-voltage activity (median voltage: 0.15 mV, mean duration: 117 ± 31 ms), terminated AT and rendered it noninducible. Additionally, ablation was performed for all of inducible ATs. At 11 ± 7 months after the procedure, 8 of 9 patients (89%) were free from any arrhythmias.
Conclusions: After ablation of long-lasting persistent AF, localized reentry may arise from a site in the vicinity of the prior ablation lesions. Ablation of the critical isthmus eliminates the arrhythmia.     

Factors related to sinus rhythm at discharge after radiofrequency ablation of permanent atrial fibrillation in patients undergoing mitral valve surgery

Late recovery of sinus rhythm is unusual in patients with permanent AF treated by (radiofrequency) RF maze procedure during mitral valve surgery. Identification of clinical and instrumental preoperative factors predictive of early success of RF ablation in patients with permanent AF undergoing mitral valve surgery may improve selection of subjects to obtain long-term results. Hundred and thirty consecutive patients with permanent AF and mitral valve disease underwent modified RF maze procedure during concomitant mitral valve surgery. Rheumatic valve disease (61 pts) and mitral valve prolapse (41 pts) were the more common aetiology of valve abnormalities. Mitral valve replacement was performed in 54 % of patients and mitral valve repair in the remaining 46 %. Four patients died after surgery. At discharge, 87 patients (69 %) were in sinus rhythm (group 1) and 43 patients in AF persisted (group 2). At an average 24-month follow-up, sinus rhythm was present in 67 % of patients, and 33 % were in atrial fibrillation. In this period, late recovery of sinus rhythm was observed only in five patients, while eight discharged in sinus rhythm developed again atrial fibrillation. Among preoperative parameters at univariate analysis female sex, atrial fibrillation >24 months, left atrial diameter >54 mm, left atrial area >24 cm², rheumatic valve disease and NYHA class were associated with persistence of AF. At Cox regression multivariate analysis, increased left atrial area (OR 1.07 per unit increase—95 % CI 1.01–1.131) and rheumatic aetiology of valve disease (OR 4.52, 95 % CI 1.65–12.4) were associated with persistence of AF at hospital discharge. Persistence of AF after RF ablation in patients undergoing mitral valve surgery is related to aetiology, e.g. rheumatic valve disease, and to increasing left atrial diameter. Due to low rate of late recovery of sinus rhythm, indication to RF ablation associated with MV surgery should be carefully considered in patients with large atria and rheumatic mitral valve disease.     

心房颤动递进式线性消融后的左心房扑动

目的旨在探讨心房颤动（房颤）递进式线性消融术中出现的房性心律失常的电生理特点及消融的结果。方法对80例房颤消融中出现规律的房性心律失常进行非接触激动顺序标测,判断电生理机制并指导消融。结果共146阵心动过速,4阵为左心房房性心动过速（房速）,周长为（225±49）ms,其余142阵为左心房扑动,左心房激动时间占心动过速周长的100％,周长为（205±37）ms,均与房颤“7”字消融线上的缝隙有关。根据缝隙的位置将心房扑动的折返环分为3类：Ⅰ类（n=68）,缝隙位于左心耳-左上肺静脉间的嵴部,Ⅱ类（n=50）,缝隙位于左心房顶部,Ⅲ类（n=24）,缝隙位于二尖瓣环峡部。其中130阵消融成功,其余16阵因消融反应欠佳后经药物或体外电转复为窦性心律。随访（16．2±6．7）个月,82．5％（66／80）的患者可维持窦性心律。结论房颤递进式线性消融术中出现的房性心律失常多为大折返机制,且与“7”字消融线上的缝隙有关,这些缝隙主要位于左心耳-左上肺静脉间的嵴部。非接触标测技术能快速准确地识别这些缝隙并指导消融。     

射频消融治疗经右心房游离壁切口术后的双环折返性房性心动过速

目的 总结经右心房游离壁切口术后双环折返性房性心动过速（房速）的发生率及射频消融后长期随访的结果.方法 2007年1月至2012年12月共入选48例在南京医科大学第一附属医院心脏科行经右心房游离壁切口治疗先天性心脏病或获得性心脏病后发作房速的患者.双环折返性房速的定义为心房同时存在两个折返环,同时在折返的可能路径上进行多部位拖带均为隐匿性.结果 共观察到8例患者术中存在双环折返性房速,男4例,平均年龄（40.4±22.0）岁.第1次外科术后至房速发作时间为（79.0±65.2）个月,第1次房速发作至第1次消融的时间为（20.8±28.3）个月,所有患者房速均持续发作.所有患者的双环折返性房速均与三尖瓣峡部以及右心房游离壁切口相关.5例患者在消融三尖瓣峡部过程中,心动周期突然变化;1例患者消融三尖瓣峡部时,心动周期无变化,右心房游离壁多部位拖带为右心房游离壁折返性房速,间隔部位拖带证实此部位不在折返环内,可能提示右心房游离壁折返性房速为主导折返环,;1例患者消融过程中心动过速终止,同样行切口致下腔的线性消融;1例患者消融三尖瓣峡部时心动过速无明显变化,但冠状静脉窦的激动有细微变化,拖带标测提示三尖瓣峡部不在折返环内,右心房游离壁多部位拖带提示为围绕右心房切口瘢痕折返的心动过速,行外科切口下部至下腔静脉消融时,房速终止.平均随访（33.6±16.7）个月,3例复发患者均为风湿性心脏病换瓣术后,其中1例复发房速,另外2例复发房颤.结论 经右心房游离壁切口术后双环折返性房速主要与三尖瓣峡部以及切口相关,三尖瓣峡部以及切口至下腔静脉线性消融常能够治疗这类心律失常.     

射频消融治疗风湿性心脏病二尖瓣置换术后房性心动过速

目的报道一组风湿性心脏病二尖瓣置换术后房性心动过速（房速）的机制及射频消融效果。方法共入选22例（男8例）二尖瓣置换术后持续性房速患者,在心动过速状态下采用三维电解剖系统建立右心房或左心房激动标测图和电压图,标出瘢痕区、低电压区及双电位区,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22例患者共标测33种心动过速,17例次房速起源于右心房（51．5％）,16例次房速起源于左心房（48．5％）。符合大折返机制的31例次（93．9％）,符合局灶起源机制的2例次（6．1％）。消融术中即时成功率90．9％（20／22）。随访过程中5例患者仍有房速发作,3例再次消融成功。结论二尖瓣置换术后房速机制复杂且个体化,在三维电解剖标测指导下射频消融治疗效果满意。     

非接触式球囊标测系统指导阵发性心房颤动个体化消融

目的探讨应用非接触式球囊三维标测系统(EnSite Array)指导下心房颤动(简称房颤)个体化射频消融的临床效果。方法18例阵发性房颤患者,应用EnSite Array三维标测房颤优势电传导部位指导个体化消融,并结合大头电极心房内描记到或虚拟电位显示为碎裂电位区进行消融,消融终点为房颤终止转窦性心律或消融线形成双向阻滞。重复术前电刺激或用异丙上腺素静脉滴注后不能诱发或诱发<30s的房颤。结果首次消融的即时成功率为94.4%(17/18),消融中1例出现心包压塞。15例行左右上肺静脉之间靠顶部心房电学改良消融,11例加左上肺静脉与左心耳之间等部位消融,6例加消融左或/和右房峡部或冠状窦口等部位消融。随访15.3±11.3个月,14例术后不服用抗心律失常药物均无房颤发生,3例房颤复发,1例出现心房扑动发作,中期成功率77.8%(14/18)。结论EnSite Array指导下实时根据房颤优势传导区个体化射频消融,消融靶点灵活、针对性强,消融创伤小,中期效果良好。     

Catheter Ablation for Long-Standing Persistent Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia worldwide and represents a major burden to health care systems. Atrial fibrillation is associated with a 4- to 5-fold increased risk of thromboembolic stroke. The pulmonary veins have been identified as major sources of atrial triggers for AF. This is particularly true in patients with paroxysmal AF but not always the case for those with long-standing persistent AF (LSPAF), in which other locations for ectopic beats have been well recognized. Structures with foci triggering AF include the coronary sinus, the left atrial appendage (LAA), the superior vena cava, the crista terminalis, and the ligament of Marshall. More than 30 studies reporting results on radiofrequency ablation of LSPAF have been published to date. Most of these are observational studies with very different methodologies using different strategies. As a result, there has been remarkable variation in short- and long-term success, which suggests that the optimal ablation technique for LSPAF is still to be elucidated. In this review we discuss the different approaches to LSPAF catheter ablation, starting with pulmonary vein isolation (PVI) through ablation lines in different left atrial locations, the role of complex fractionated atrial electrograms, focal impulses and rotor modulation, autonomic modulation (ganglionated plexi), alcohol ablation, and the future of epicardial mapping and ablation for this arrhythmia. A stepwise ablation approach requires several key ablation techniques, such as meticulous PVI, linear ablation at the roof and mitral isthmus, electrogram-targeted ablation with particular attention to triggers in the coronary sinus and LAA, and discretionary right atrial ablation (superior vena cava, intercaval, or cavotricuspid isthmus lines).     

以终止持续性心房颤动为手术终点的递进式消融200例总结

目的总结递进式消融术式治疗持续性心房颤动(简称房颤)的手术过程及临床转归。方法采用递进式消融策略治疗连续200例持续性房颤患者,手术终点为通过单纯消融终止房颤。按以下顺序进行消融:环肺静脉前庭消融达肺静脉电学隔离;心房碎裂电位消融;左房顶部和二尖瓣环峡部线性消融;针对房颤转变而成的房性心动过速(简称房速)行激动标测结合拖带技术明确其机制,并进一步消融终止。经术后3个月空白期,对复发房性心律失常(房颤/房速)的患者进行再次消融。结果 136例患者(68%)术中房颤被消融终止,消融终止房颤组首次术后房性心律失常复发率显著低于未终止组[19.9%(27/136)vs 51.6%(33/64),P<0.01],复发患者经再次消融后,平均随访12.8±7.2个月,本组病例总体手术成功率78.5%(157/200)。消融终止房颤组手术总体成功率高于未终止组[(86.8%(118/136)vs 60.9%(39/64),P<0.01)]。结论递进式消融可能是治疗持续性房颤的一种有效术式。     

Arrhythmia recurrence in patients following cardiac surgery with concomitant therapy of atrial fibrillation – Experience of our cardiac center

IntroductionSurgical treatment of atrial fibrillation (AF) is a common and time-proven treatment method for this type of arrhythmias both as a separate procedure and as a procedure related to cardiac surgery for another indication (concomitant procedure). Patients experience arrhythmia recurrence despite highly efficient surgical treatment. These arrhythmias are often resistant to pharmacological treatment (due to an extensive fibrous substrate); therefore, electroanatomical mapping accompanying catheter ablation is significantly more effective. The arrhythmogenic fibrous substrate is a result of both a primary cardiac disease (an underlying disease causing atrial dilation) and surgical intervention (incision, cannula insertion sites, MAZE lines with a renewed spread of electrical signal in these blocks).Method and patientsElectroanatomical mapping and ablation were performed in 92 patients with arrhythmia recurrence following concomitant surgical treatment for AF between January 2010 and November 2015. The Cox maze procedure was performed using a disposable cryoablation catheter. The heart rhythm in patients following radiofrequency ablation procedure was monitored in half-year intervals (24-h Holter ECG, 7-day loop recorder, in some patients also by means of implanted pacemakers or implantable loop recorders). The average left atrial size (PLAX) was 50 mm, 59% of patients underwent mitral valve surgery, 54% of patients had tricuspid valve surgery, 16% were operated for congenital developmental disorders, in 17% of patients, repeated cardiac surgery was performed. The above-mentioned facts show that these are patients with an extensive arrhythmogenic substrate.ResultsThe Cox maze procedure resulted in an extensive fibrous arrhythmogenic substrate in the atrium (arrhythmia recurrence following the maze procedure is more often regular atrial tachycardias while AF is predominant among arrhythmias for which the maze procedure was indicated). All patients had a follow-up visit after 12 months, 80% of patients presented for a follow-up visit after 24 months. Early recurrence after ablation (within 3 months following the procedure) was found in 21% of patients. Early recurrence after ablation was statistically significantly related to arrhythmia recurrence within 12 months (p = 0.003) and arrhythmia recurrence within 24 months (p = 0.003). 73% of patients had no recurrent AF or atrial tachycardia (AT) after 12 months and 53% after 24 months. A total of 146 arrhythmias were ablated, i.e. 1/3 of patients had more than 1 arrhythmia. These were persistent AF found in 24% of patients, paroxysmal AF seen in 13% of patients and regular AT detected in 53% of patients. More than one half of regular AT originated in LA (as perimitral atrial flutter in most cases). Remaining arrhythmias originated from the right atrium (as typical atrial flutter in half of the cases). 57% of patients had a renewed spread of signal in the mitral isthmus (ablation of the coronary sinus was necessary in 1/3 of patients). No domination in the number of reconnections was found for any of the pulmonary veins. The finding of a significantly reduced signal amplitude in the entire LA was associated with a higher risk of acute ablation failure (p = 0.001). Acute ablation failure was associated with a higher risk of arrhythmia recurrence after 12 months (p = 0.07). There was a trend of a higher AT incidence originating from the RA in patients who underwent surgery for a congenital heart defect (p = 0.06). The diagnosis of arterial hypertension was associated with a higher risk of arrhythmia recurrence (p = 0.13). The finding of persistent AF on ECG (compared to other findings, i.e. paroxysmal AF and regular AT) before ablation did not increase the risk of recurrence after ablation.ConclusionIn patients after cardiac surgery, catheterization performed to treat arrhythmia recurrence is a effective method of subsequent treatment, despite an extensive arrhythmogenic substrate. A rather large number of AT cases originate from the right atrium, in particular in patients after surgery for congenital heart defects. Patients with a significantly reduced signal in the larger part of the atrium due to an extensive arrhythmogenic substrate present the most complicated cases.     

Left atrial ablation versus biatrial ablation for persistent and permanent atrial fibrillation: a prospective and randomized study.

OBJECTIVES: The aim of this study was to compare--in patients with persistent and permanent atrial fibrillation (AF)--the efficacy and safety of left atrial ablation with that of a biatrial approach. BACKGROUND: Left atrium-based catheter ablation of AF, although very effective in the paroxysmal form of the arrhythmia, has an insufficient efficacy in patients with persistent and permanent AF. METHODS: Eighty highly symptomatic patients (age, 58.6 +/- 8.9 years) with persistent (n = 43) and permanent AF (n = 37), refractory to antiarrhythmic drugs, were randomized to two different ablation approaches guided by electroanatomical mapping. A procedure including circumferential pulmonary vein, mitral isthmus, and cavotricuspid isthmus ablation was performed in 41 cases (left atrial ablation group). In the remaining 39 patients (biatrial ablation group), the aforementioned approach was integrated by the following lesions in the right atrium: intercaval posterior line, intercaval septal line, and electrical disconnection of the superior vena cava. RESULTS: During follow-up (mean duration 14 +/- 5 months), AF recurred in 39% of patients in the left atrial ablation group and in 15% of patients in the biatrial ablation group (p = 0.022). Multivariable Cox regression analysis showed that ablation technique was an independent predictor of AF recurrence during follow-up. CONCLUSIONS: In patients with persistent and permanent AF, circumferential pulmonary vein ablation, combined with linear lesions in the right atrium, is feasible, safe, and has a significantly higher success rate than left atrial and cavotricuspid ablation alone.     

Impact of atrial fibrillation on clinical status, atrial size and hemodynamics in patients after mitral valve replacement.

BACKGROUND AND AIM OF THE STUDY: The association between mitral valve disease and atrial fibrillation (AF) is well known, but few data exist regarding the impact of AF after mitral valve replacement (MVR) on NYHA functional class, atrial size and hemodynamic parameters. The present study was conducted to evaluate these issues. METHODS: Eighty-six patients (26 men, 60 women) who underwent MVR were evaluated by transthoracic echocardiography. Fifty-nine patients had chronic AF (AF group), and 27 were in sinus rhythm (sinus group). Variables analyzed included end-systolic left atrial and right atrial areas, tricuspid regurgitation, and presence and duration of AF. Peak and mean transprosthetic mitral valve gradients and pulmonary pressure were estimated by Doppler echocardiography. RESULTS: Groups were matched for age, sex and time from MVR (mean 6.6 years). Sixty-four patients (77%) had rheumatic heart disease, 18 (21%) had mitral valve disease, and two (2%) had mitral valve prolapse. Mean duration of AF was 11+/-12 years (range: 8-50 years). Preoperatively, AF patients had a worse NYHA class than sinus patients (2.8+/-0.8 versus 1.1+/-0.7, p = 0.001), but both had similar fractional shortening of the left ventricle and preserved prosthetic mitral valve function. Multivariate analysis identified AF as a single predictor of NYHA class after MVR. Although left and right atrial areas were larger in AF patients (47+/-25 versus 27+/-7 cm2, p = 0.0001 and 30+/-12 versus 17+/-5 cm2, p = 0.0001, respectively), the left:right atrial size ratio was not significantly different between groups. Multivariate analysis identified mean transmitral gradient and duration of AF as independent predictors of left atrial size after MVR (p = 0.01 and p = 0.0001, respectively). Tricuspid regurgitation and duration of AF were independent predictors of right atrial size (p = 0.003 and p = 0.0001, respectively). CONCLUSION: The presence of AF after MVR is associated with a worse NYHA functional class, increased transmitral gradients, and larger areas of both atria, when compared with sinus rhythm. Hence, a special effort should be made to correct arrhythmia during surgery, and in case of paroxysmal arrhythmia, earlier surgery should be considered before the condition becomes chronic.     

Superior left atrial approach to the mitral valve: incidence of postoperative arrhythmia

BACKGROUND AND AIM OF THE STUDY: The superior left atrial approach to mitral surgery involves exposure of the mitral valve through a longitudinal, craniocaudally orientated incision in the roof of the left atrium. The study aim was to evaluate the incidence of postoperative arrhythmias following this procedure. METHODS: Fifty-nine patients underwent either mitral valve repair (n = 20), mitral valve replacement (n = 26) or an associated procedure (n = 13), including aortic valve replacement, coronary artery bypass grafting and atrial septal defect closure. Eight patients had undergone previous surgery on the mitral valve. Patients were classified according to their preoperative rhythm: sinus rhythm (SR), paroxysmal or chronic atrial fibrillation (AF), or permanent pacing. Changes in cardiac rhythm were evaluated postoperatively, after four weeks, and at late follow up (mean 23.8 months). RESULTS: Preoperatively, 24 patients had shown SR, 10 had paroxysmal AF, 24 had chronic AF, and one patient had permanent pacing. At the time of discharge, SR was recorded in 18 patients who had SR preoperatively, in seven who had paroxysmal AF preoperatively, and in one patient who had chronic AF preoperatively. At follow up, SR was seen in 19 patients with preoperative SR, in seven with paroxysmal AF preoperatively, and in two with chronic AF preoperatively. Four patients received permanent pacemakers postoperatively due to total heart block or bradycardia. CONCLUSION: The superior left atrial approach to mitral valve surgery appears to be safe as it maintains the sinus rhythm in a high proportion of patients postoperatively. In addition, it is not normally prone to technical complications.