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.     

The biophysics and biomechanics of cryoballoon ablation

Recent clinical and preclinical studies have demonstrated that cryothermal ablation using a balloon catheter (Artic Front®, Medtronic CryoCath LP, Pointe‐Claire, Canada) provides an effective means of achieving pulmonary vein isolation. This review explores the biophysics and biomechanics of cryoballoon ablation. Components of the cryoballoon catheter system are examined, mechanisms of cryothermal injury are summarized, and potential advantages of cryoballoon technology over standard radiofrequency ablation in isolating pulmonary veins are discussed. Practical aspects of biophysics and biomechanics relevant to the clinical electrophysiologist are emphasized, particularly with regards to the selection of the most appropriate cryoballoon catheter and minimizing peri‐procedural complications. (PACE 2012; 35:1162–1168)     

Major complications of cryoballoon catheter ablation for atrial fibrillation and their management

Atrial fibrillation (AF) is the most common symptomatic and sustained cardiac arrhythmia. It affects approximately 2–3 million people in the USA alone with an increased incidence and prevalence worldwide. It is associated, in addition to worsening quality of life, with increased morbidity and mortality especially in poorly controlled AF, affecting mostly those older than 65 years of age. Radiofrequency ablation was found to be a good strategy for focal isolation of pulmonary veins triggering from the vulnerable atrial substrate but is a time-consuming procedure and carries the risk of multiple complications like tamponade which could be fatal, atrioesophageal fistula and local thrombus formation at the site of ablation. Cryoballoon ablation with pulmonary vein isolation has emerged in the past few years as a breakthrough novel technology for the treatment of drug-refractory AF. It is a relatively simple alternative for point-by-point radiofrequency ablation of paroxysmal AF and is associated with fewer incidences of fatal complications such as cardiac perforation. As experience with this new tool accumulates, the field faces new challenges in the form of rare compilations including gastroparesis, phrenic nerve palsy, atrioesophageal fistula, pulmonary vein stenosis, thromboembolism pericardial effusion, and tamponade.     

Antiarrhythmic therapy following ablation of atrial fibrillation

Antiarrhythmic drugs (AADs) are often used after ablation for atrial fibrillation (AF); the drugs employed vary, but most common are the drugs that were unsuccessful prior to ablation since it seems that the efficacy of AADs might substantially increase after catheter ablation of AF. AADs reduce early recurrences of atrial tachyarrhythmias after AF catheter ablation, whereas they did not prevent arrhythmia recurrences occurring later. Several upstream therapies (angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, statins, corticosteroids and colchicine) have been tested with conflicting results. To date, there is no sufficient evidence to support the use of any upstream therapy after AF catheter ablation. Larger registries and controlled clinical trials in well-defined patient groups and with well-defined outcome parameters are required to further elucidate the role of AADs after AF ablation.     

第二代冷冻球囊导管治疗阵发性心房颤动病人围术期的护理

[目的]探讨应用第二代冷冻球囊导管行冷冻消融治疗阵发性心房颤动病人围术期的护理。[方法]选择26例拟行冷冻球囊消融术的阵发性心房颤动病人,术前进行严格护理管理,术中给予全面护理配合,术后进行护理评估及干预。[结果]术中5例病人出现迷走反射,2例病人出现恶心;术后1例病人出现咯血,1例病人出现股静脉血肿,经相应治疗后均缓解。[结论]应用第二代冷冻球囊治疗阵发性心房颤动病人,围术期需要护理的全面配合。     

Impact of impaired renal function and metabolic syndrome on the recurrence of atrial fibrillation after catheter ablation: a long term follow-up

Background: The goal of this study was to analyze impact of metabolic syndrome (MetS) and impaired renal function on long‐term follow‐up after catheter ablation of atrial fibrillation (AF). Methods and Results: A total of 702 consecutive patients with AF (age = 58 year, history of AF = 5 year, male = 478, paroxysmal atrial fibrillation = 416, coronary artery disease = 62, hypertension = 487) considered for catheter ablation were enrolled in the study. The MetS was diagnosed at admission in 276 patients. The renal function was estimated by glomerular filtration rate (eGFR). Pulmonary vein isolation (PVI) was performed either with cryoballoon technique (n = 260) or circumferential PVI (n = 442) with a 3.5‐mm irrigated tip catheter. A 7‐day‐Holter electrocardiogram was performed at each follow‐up visit. Any episode of documented AF after an initial 3‐month blanking period was considered as clinical endpoint. Out of 702 patients, 370 (52.7%) were free of AF recurrences at median follow‐up of 15 six interquartile range (12.7–42.3) months. The patients with MetS had significantly lower success rate than those without (128/276 (46.4%) vs 242/426 (56.8%), P = 0.006). Among 103 patients with eGFR < 68 mL/min only 35 (34%) were free of recurrences compared with 335/599 (55.9%) in patients with GFR ≥ 68 mL/min (P = 0.001). Both parameters were revealed in multivariate analysis to be independent predictors for outcome after catheter ablation. Conclusion: The results of our study clearly demonstrated that outcome after 1st catheter ablation of AF is poor in patients with MetS and/or impaired renal function. This observation has a potential clinical impact for the follow up management of these patients. (PACE 2012;1–12)     

左房容积指数用于预测心房颤动患者射频消融后复发的meta分析

目的 评价左房容积指数(left atrial volume index,LAVI)用于预测心房颤动(atrial fibrillation,AF)患者射频消融术后复发的临床价值。方法 计算机检索PubMed、the Cochrane Library、Web of Science、中国知网、中国生物医学文献数据库、维普数据库等,查找LAVI用于预测AF患者射频消融后复发的相关文献。采用STATA 12.0进行meta分析。结果 共纳入13项研究1 519例AF患者。Meta分析结果显示与AF射频消融后未复发患者相比,复发患者平均LAVI更高(SMD=2.51, 95%CI:1.61～3.41,P=0.001),同时AF射频消融后未复发患者与复发患者LAV/LAVI两组间差异有统计学意义(OR=2.88,95%CI:2.68～3.10,P=0.001),提示AF患者接受射频消融术后密切监测LAVI变化可有效评估其术后复发的可能性。结论 与AF射频消融术后未复发的患者相比,复发的患者平均LAVI更高,其可作为评估AF患者接受射频消融术后复发的有效指标。结论仍需更多多中心、大样本的随机对照试...     

Different clinical courses and predictors of atrial fibrillation occurrence after transisthmic ablation in patients with preablation lone atrial flutter, coexistent atrial fibrillation, and drug induced atrial flutter

The aim of this prospective study was to compare the long-term follow-up after transisthmic ablation of patients with preablation lone atrial flutter, coexistent AF, and drug induced atrial flutter to determine if postablation AF followed a different clinical course and displayed different predictors in these groups. The study evaluated 357 patients who underwent transisthmic ablation for typical atrial flutter. These were divided into four groups according to their preablation history. Group A included patients with typical atrial flutter and without preablation AF (n=120, 33.6%). Group B included patients with preablation AF and spontaneous atrial flutter (n=132, 37.0%). Group C patients had preablation AF and atrial flutter induced by treatment with IC drugs (propafenone or flecainide) (n=63, 17.6%) Group D included patients with preablation AF and atrial flutter induced by treatment with amiodarone (n=42, 11.8%). During a mean follow-up of 15.2 double dagger 10.6 months (range 6-55 months) AF occurred more frequently in groups B (56.1%) and C (57.1%) patients than in groups A (20.8%, P <0.0001) and D (31.0%, P <0.0001) patients. The results of multivariate analysis revealed that different clinical and echocardiographical variables were correlated with postablation AF occurrence in the different groups. Patients with atrial flutter induced by amiodarone have a significantly lower risk of postablation AF than patients with spontaneous atrial flutter and AF, and those with atrial flutter induced by IC drugs. Different clinical and echocardiographical variables predict postablation AF occurrence in different subgroups of patients.     

Catheter ablation vs. amiodarone plus losartan for prevention of atrial fibrillation recurrence in patients with paroxysmal atrial fibrillation

Background  Although amiodarone plus angiotensin II receptor blockers (ARBs) and catheter ablation may improve sinus rhythm maintenance of paroxysmal atrial fibrillation (AF), their clinical efficacies have not been compared. This prospective cohort study was designed to compare clinical efficacy of catheter ablation and amiodarone plus losartan on sinus rhythm maintenance in patients with paroxysmal AF.
Materials and methods  A total of 240 patients with paroxysmal AF were assigned to four groups. CPVA group ( n =  60) was treated with circumferential pulmonary vein ablation (CPVA), SPVI group ( n  = 60) with segmental pulmonary vein isolation, AMIO group ( n  = 60) with amiodarone and AMIO + LO group ( n  = 60) with amiodarone plus losartan. The endpoint was documented recurrence of AF > 30 s by Holter or conventional 12-lead ECG in the 1-year follow-up period.
Results  During 12 months of follow-up, the primary end point was reached in 28 patients in CPVA group, 14 patients in SPVI group, 25 patients in AMIO group and 13 patients in AMIO + LO group, respectively. The sinus rhythm in SPVI and AMIO + LO group were significant higher than that in CPVA and AMIO group ( P  < 0·01 and 0·025), and no difference between CPVA and AMIO group. The maintenance rate of sinus rhythm in SPVI group was similar to that in AMIO + LO group.
Conclusions  This study demonstrates that segmental pulmonary vein isolation in preventing AF recurrence is similar to amiodarone plus losartan, but it is superior to CPVA and amiodarone alone in patients with paroxysmal AF. Larger multicentre studies are needed to confirm its long-term outcomes.     

Catheter ablation of atrial fibrillation: long-term outcomes

The benefits of percutaneous coronary intervention (PCI) can be offset by periprocedural complications such as acute vessel closure and stent thrombosis in the absence of adequate antiplatelet and antithrombotic therapy. Additionally, conditions occurring after 30 days post-PCI, such as in-stent restenosis or late stent thrombosis can occur. Excess antithrombotic therapy, on the other hand, carries a risk of major gastrointestinal or intracranial bleeding as well as vascular access site bleeding complications. In this review, evidence related to the various pharmacological agents for reduction of stent thrombosis available to clinicians during and after PCI will be explored.