Catheter ablation of atrial fibrillation in patients with hyperthyroidism

Aims To study the clinical efficacy of catheter ablation for treating patients with hyperthyroidism-related atrial fibrillation (AF). Materials and methods The study involved 16 patients (12 males; age, 59.8 ± 11.3 years) with hyperthyroidism-related AF, who had all been euthyroid for more than 3 months but still suffered from highly symptomatic and antiarrhythmia drug (AAD)-refractory AF. Circumferential pulmonary vein ablation (CPVA) guided by a 3-D mapping system was carried out to encircle the ipsilateral pulmonary veins (PVs) with a procedural endpoint of continuity of the circular lesions and PV isolation. Success was defined as the absence of any atrial tachyarrhythmia (ATa) off AADs beyond the first 3 months after the procedure. Results CPVA was safely carried out in each of the 16 patients without any complications. PV isolation was achieved in all the treated PVs. After a mean follow-up of 15.8 ± 11.8 (range, 6–55) months, 9 patients (56%) were free of ATa without any AADs beyond the first 3 months. AF relapsed in the remaining 7 patients, among whom 4 responded to AAD therapy and 3 were totally unresponsive. Conclusion For patients suffering hyperthyroidism-related AF, CPVA guided by a 3-D mapping system could represent one of the therapeutic options. Drs. Chang Sheng Ma and Xu Liu are co-first authors for this paper.     

Catheter ablation of atrial fibrillation in the elderly

Background Atrial fibrillation （AF） catheter ablation has emerged as a promising treatment strategy for AF, but has not been widely adopted in the elderly population. The present study aimed to determine the safety and efficacy of AF catheter ablation in the elderly popula-tion. Methods and Results The study population consisted of 316 patients with paroxysmal AF who underwent left atrial ablation. Ninety-five patients were≥65 years （48 males, mean age 68.9 ± 3.0 years old） and 221 patients were〈65 years old （130 males, mean age 52.5 ± 10.4 years old）. After a mean follow-up period of 34.0 ± 15.1 months, 55 （57.9%） patients in the elderly group were free from ar-rhythmia recurrence compared with 149 （67.4%） patients in the younger group （P=0.169）. Procedural complications were uncommon in both study groups. In logistic regression analysis, left atrial diameter （P=0.003）, hypertension （P=0.001）, dyslipidemia （P=0.039）, and coronary artery disease （P=0.018） were independent predictors of AF recurrence in the elderly population. Conclusions Catheter ablation of AF is safe and effective in older patients. Invasive strategies should be considered as an alternative choice in symptomatic elderly patients with AF.     

递进式个体化心房基质消融治疗心房颤动

目的 以肺静脉电学隔离为终点的心房颤动（房颤）消融术式的疗效难以令人满意。本研究旨在探索规范化的递进式个体化心房基质改良消融术治疗房颤的方法。方法 124例患者（男性96例,女性28例）,年龄27-76（53．6±8．7）岁。其中92例为阵发性房颤,32例为持续性／永久性房颤。若无自发房颤则在心房进行持续递增的快速刺激（频率200—600次／min）诱发房颤。均在非接触式标测观察房颤时心房激动情况,将最常激动部位做为房颤基质进行改良消融,并根据消融后重复等电位标测的结果作出递进式调整,直至房颤被终止不再被诱发。结果 在既不隔离肺静脉也不寻求碎裂电位的情况下,87．1％（108／124）的房颤消融转复为窦性心律,其余被转为非典型心房扑动（房扑）或房性心动过速（房速）。可将消融灶分为3种类型,其中以7字形的A型线性消融最关键,71．6％的阵发性房颤可被A型消融终止且不再被诱发,而68．8％的持续性／永久性房颤则需通过B型消融终止。随访（21．6±5．3）个月,90．3％（112／124）的患者不服药亦无房颤发生。其余9．7％（12／124）的患者有顽固性非典型房扑／房速,其中仅1．6％（2／124）的患者伴有阵发性房颤。结论 递进式的心房基质消融术可以将房颤有效地转复为窦性心律,并有满意的远期疗效。此种术式简单易行有望在NavX和Carto标测下复制。     

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。     

Surgical ablation devices for atrial fibrillation

The introduction of ablation technology has revolutionized the surgical treatment of atrial fibrillation (AF). It has greatly simplified surgical approaches and has significantly increased the number of procedures being performed. Various energy sources have been used clinically, including cryoablation, radiofrequency, microwave, laser, and high-frequency ultrasound. The goal of these devices is to create conduction block to either block activation wavefronts or to isolate the triggers of AF. All present devices have been shown to have clinical efficacy in some patients. The devices each have their unique advantages and disadvantages. It is important that surgeons develop accurate dose-response curves for new devices in clinically relevant models on both the arrested and beating heart. This will allow the appropriate use of technology to facilitate AF surgery. This work was supported by NIH grants 2RO1HL032257 and T32HL007776.     

Results of complex left atrial ablation of long-lasting persistent atrial fibrillation

PURPOSE: The aim of the study was to identify variables associated with successful long-term maintenance of sinus rhythm (SR) after a single ablation of long-lasting persistent atrial fibrillation (AF). METHODS: Complex left atrial (LA) ablation was performed in 100 patients. Restoration of SR by ablation was the desired procedure endpoint. RESULTS: SR was restored by ablation in 38 patients during the first procedure. Following one ablation, 50 patients remained in SR for 31 +/- 14 months. SR maintenance was associated with shorter duration of the persistent AF (median 14 vs. 22 months; P = 0.05), lower proportion of the LA points exhibiting voltage <0.2 mV (median 20% vs. 33%; P = 0.006), and higher proportion of LA points showing voltage >1 mV (median 15% vs. 11%; P = 0.02). CONCLUSION: Among clinical variables, shorter duration of persistent AF and higher voltage recorded around the LA predicted long-term maintenance of SR after single ablation.     

Catheter ablation for atrial fibrillation in patients with the Marfan and Marfan-like syndromes

Patients with the Marfan syndrome may pose a difficult challenge for catheter-based interventions due to frequent coexisting valve disease, potential delay in vascular healing and repair, and intra-atrial scar from prior cardiac surgery. We report a case series of four patients with Marfan or Marfan-like syndromes who underwent ablation for drug-refractory atrial fibrillation. Ultimately three of four patients remained in sinus rhythm, however most patients required multiple ablative attempts and long-term atrial flutter was common. Nonetheless, peri-procedural complications were minimal despite the connective tissue disorder and prosthetic valves in three of four patients. In conclusion, catheter ablation of AF in patients with Marfan syndrome is a viable option in those individuals refractory to conventional therapy.     

心房颤动导管消融：更上一层楼

十余年来,心房颤动（房颤）导管消融已经从一项探索中的技术发展为广泛应用的房颤治疗方法,其进展日新月异.目前,房颤导管消融的技术更成熟,风险效益比更明确,普及更广泛,已然进入了快速发展的成熟时期.     

射频导管消融治疗青年人群心房颤动的临床分析

目的 对青年心房颤动（房颤）患者（≤45岁）接受三维标测系统指导下房颤射频导管消融治疗的临床疗效和安全性予以研究.方法 回顾分析兰州军区兰州总医院自2011年1月至2012年5月在EnSite 3000指导下接受房颤射频消融治疗的152例患者,按年龄分为青年房颤患者（≤45岁）和中老年房颤患者（＞45岁）,对比分析其在临床基线资料、消融术时间、X线曝光时间、住院天数、术后复发率、术后6个月服药率和并发症发生率等临床指标上的差异.结果 与中老年房颤患者（n=125）相比,青年房颤患者（n=27）多以阵发性房颤为主（P＜0.05）,且术前左心房内径较小（P＜0.01）,消融术时间明显缩短（P＜0.01）,术后住院天数减少（P＜0.01）,复发率和术后6个月服药率均明显减少（P＜0.05）.结论 青年房颤患者多以阵发性房颤为主且较少伴有高血压、糖尿病等疾病,接受房颤消融术后恢复较快且房颤复发率低.     

Radiofrequency catheter ablation of atrial fibrillation in older patients: outcomes and complications

Introduction  Catheter ablation (CA) of atrial fibrillation (AF) has become a treatment option for younger patients with drug refractory AF. It is not known whether pulmonary veins (PV) have an important mechanistic role in elderly patients with AF or whether CA is an effective treatment for the elderly. Methods  We evaluated 240 consecutive patients that were referred to the electrophysiology laboratory for CA for AF using a PV antral isolation approach. Linear ablations were not routinely performed. Clinical outcomes and healthcare resource utilization was evaluated during the 12 months after CA in patients <65 years old (Group 1; 91 patients), 65–75 years old (Group II; 88 patients), and >75 years old (Group III; 61 patients). Results  Older patients were more likely to have persistent atrial fibrillation (I: 24%, II: 34%, III: 66%). Major complication rates (I: 1%; II: 1%; III: 0%; p=ns) and minor complication rates (I: 4%; II: 5%; III: 5%; p=ns) were similar for all three groups. At 12 month follow-up younger patients were more likely to be in sinus rhythm without prolonged episodes of atrial fibrillation without antiarrhythmic drug therapy (AARx) (I: 94%, II: 84%, III: 61%). However in Group III, effective treatment (AF <1 h/mo ± AARx) was achieved in 82% of patients. After radiofrequency catheter ablation, hospitalizations, emergency room and nonroutine clinic visits decreased significantly for all three groups during the 12 months after RFA (I: pre 22; post: 3; Group II: pre 26; post 4; III: pre 20; post 2). Conclusions  CA can be effective for treating AF in selected older patients as stand-alone therapy or as hybrid therapy with AARx. PVs appear to be an important arrhythmogenic structure regardless of age. CA is associated with decreased healthcare resource utilization in all age groups.     

心房颤动导管消融的现状与前景

Atrial fibrillation (AF) is a common arrhythmia associated with significant morbidity and mortali-ty. In 1998, Haissaguerre and his colleagues described focal firing as an important source of ectopic beats, which could lead to AF. Further studies propelled the evolution of the technique to the circumferential isolation of the pul-monary vein (CIPV), which has since become the cornerstone of curative paroxysmal AF with a higher success rate. There is a debate about the strategy of catheter ablation for long-standing persistent or permanent AF. Differ-ent catheter strategies, for example, CIPV, CIPV + additional linear ablations, and CFAE (complex fractionated at-rial eleetrograms), which have different success rate. Catheter ablation of AF is mushroom growth in China. The success rate of AF is similar with overseas centers, which was testified by the 2007 register study of AF catheter ab-lation in China. Catheter ablation of AF must have bright future with deeply ascertainment the mechanism of AF.     

Long-term follow-up after radiofrequency catheter ablation for atrial fibrillation

Aims: Data on long-term follow-up of patients who have undergone catheterablation for atrial fibrillation (AF) are very limited. Thisreport aimed at presenting clinical outcome and AF-free survivalafter pulmonary vein (PV) isolation over an extended (>3years) follow-up period. Methods and results: Thirty-nine patients subjected to PV isolation for paroxysmalAF were followed-up for at least 3 years according to a strictprotocol. Fourteen patients (35.8%) had one, 19 patients (50%)had two, and 6 patients (15.4%) had three ablation procedures.At end of follow-up (42.2 ± 6.0 months), 17 patients(43.5%) were completely free of AF or other atrial arrhythmia,and 26 patients (66.6%) had symptomatic improvement. The long-termsuccess rate was 21.4% for patients subjected to a single ablationprocedure, 52.6% for patients subjected to two catheter ablationprocedures, and 66.7% for patients who underwent three ablationprocedures (P = 0.094). There was also a trend for patientswho underwent a combination of different ablation procedures(ostial, antral, and/or circumferential) to have a higher AF-freesurvival when compared with patients subjected to the same procedure(P-value for log-rank test = 0.036). Conclusion: Catheter ablation does not eliminate paroxysmal AF in up to56% of patients in the long term, despite the use of two orthree ablation procedures in two-thirds of them. However, itconfers symptomatic improvement in 67% of treated patients.     

Atrial fibrillation ablation complications

Atrial fibrillation (AF) is a common arrhythmia. Although significant work still needs to be done, recent advances in understanding the mechanisms of AF have led to the development of elegant catheter mapping techniques for ablation of AF, complemented by the evolution of various imaging and navigational technologies. Due to the complexity of the arrhythmia, and the significant length of time needed to successfully ablate in the left atrium, it is imperative that an acceptable risk-benefit profile be defined. Various complications, some of them serious, have been reported in the last several years. This review addresses the potential risks of AF ablation and how to avoid some of these complications.     

Atrial fibrillation: Catheter ablation

Catheter ablation of atrial fibrillation (AF) has evolved dramatically over the last several years. The initial efforts in the catheter-based management of AF targeted the atrial substrate in an effort to mimic the maze procedure. After the pulmonary veins (PV) were shown to be critical in the initiation and perpetuation of AF, the focus then shifted to a trigger approach in which the PVs and other foci were targeted for ablation. The pendulum then appeared to swing back toward the substrate approach after it was shown that left atrial circumferential ablation afforded improved outcomes in patients with paroxysmal and persistent AF. It has become clear that there are several possible approaches in the catheter ablation of AF, each with its strengths and limitations. It is also becoming evident that not all patients will respond to a single ablation technique and that the ablation protocol is best tailored to suit the individual patient. This article strives to present an evidence-based review of the many techniques, and then offer a practical guide to the catheter ablation of AF.