The efficacy of high-power short-duration radiofrequency for atrial fibrillation ablation: A protocol for systematic review and meta-analysis

Background:Studies comparing data between the high-power short-duration radiofrequency (HPSR) and low power longer duration therapy were limited and inconsistent. Therefore, we conduct a high-quality systematic review and meta-analysis to assess the efficacy and safety of HPSR on outcomes for patients with atrial fibrillation (AF).Methods:The online literature is searched using the following combination of medical subject heading terms: “high-power” OR “high power” AND “radiofrequency” AND “atrial fibrillation.” MEDLINE (PubMed), EMBASE (OVID), Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science (ISI database) will be searched without any language restrictions. All clinical trials to assess the efficacy and safety of HPSR in the treatment of atrial fibrillation will be considered eligible for analysis. The present study will be performed by Review Manager Software (RevMan Version 5.3, The Cochrane Collaboration, Copenhagen, Denmark). Ethical approval and patient consent are not required because this study is a literature-based study.Results:This study expects to provide credible and scientific evidence for the efficacy and safety of HPSR on outcomes for patients with AF.Registration number:10.17605/OSF.IO/WAEBN.     

The effect of left atrial remodeling after cryoballoon ablation and radiofrequency ablation for paroxysmal atrial fibrillation

BackgroundCryoballoon ablation (CBA) and radiofrequency ablation (RFA) are the most common procedures used to treat refractory atrial fibrillation (AF) and are performed through pulmonary vein isolation (PVI). Studies have shown that CBA can approximately match the therapeutic effects of RFA against AF. However, few studies have investigated the difference between CBA and RFA of the effects on left atrial remodeling for paroxysmal AF.ObjectiveAtrial remodeling is considered pivotal to the occurrence and development of AF, therefore we sought to assess the influence of atrial remodeling in patients with paroxysmal AF after CBA and RFA in this study.MethodsIn this nonrandomized retrospective observational study, we enrolled 328 consecutive patients who underwent CBA or RFA for refractory paroxysmal AF in May 2014 to May 2017 in our hospital. After propensity score matching, 96 patients were included in the CBA group, and 96 were included in the RFA group. Patients were asked to undergo a 12‐lead electrocardiogram, a 24‐h Holter monitor, and an echocardiogram and to provide their clinical history and symptoms at 6 months and 1, 2, and 3 years postprocedurally. Electrical remodeling of the left atrium was assessed by P wave dispersion (Pdis); structural remodeling was assessed by the left atrium diameter (LAD) and left atrial volume index (LAVI) during scheduled visits.ResultsAs of January 2020, compared with baseline, at 1 year, 2 years, and 3 years after ablation, the average changes in Pdis (∆Pdis), LAD (∆LAD), and LAVI (∆LAVI) were significant in both the CBA and RFA groups. Six months after ablation, ∆Pdis, ∆LAD, and ∆LAVI were greater in the CBA group than in the RFA group. There was no significant difference between the two groups in AF/flutter recurrence, but the AF/flutter‐free survival time of CBA group may be longer than RFA group after 2 years after ablation. A higher ∆Pdis, ∆LAD, or ∆LAVI at 1 year after ablation may increase AF/flutter‐free survival.ConclusionsAlthough CBA and RFA are both effective in left atrial electrical and structural reverse‐remodeling in paroxysmal AF, CBA may outperform RFA for both purposes 6 months after ablation. However, during long‐term follow‐up, there was no significant intergroup difference.     

Pulmonary edema after extensive radiofrequency ablation for atrial fibrillation

Background: More extensive ablation strategies for the treatment of atrial fibrillation (AF) have increased success rates but are associated with new and sometimes serious complications. We describe a new complication after extensive radiofrequency (RF) ablation in the left atrium (LA) for persistent AF.
Methods and Results: Electroanatomic guided circumferential ablation around both ipsilateral pulmonary veins (PV) was performed with the endpoint of complete conduction block. When necessary, supplementary RF applications were added, including ablation of complex fractionated potentials and/or isolation of other thoracic veins and/or linear left atrial lesions. RF energy was delivered via an irrigated tip catheter with a maximum power of 30–35 W. Four out of 120 patients undergoing extensive RF ablation for persistent AF (including two patients with additional LA substrate modification) developed dyspnea, bilateral pulmonary edema, and signs of a systemic inflammatory response syndrome (SIRS) (rise in body temperature, leukocyte count, and C-reactive protein (CRP levels) 18–48 hours after the procedure. There were no signs of PV stenosis, focal lung injury, left ventricular dysfunction, circulatory failure, or infection. All patients had complete recovery with supportive therapy within 3–4 days after the onset of symptoms.
Conclusions: Extensive LA radiofrequency ablation bears the risk of a severe pulmonary edema. Although the precise mechanism is elusive, clinical features point toward a systemic inflammatory response.     

Left atrial flutter after radiofrequency catheter ablation of focal atrial fibrillation

We report an arrhythmic complication in two patients in whom a procedure directed at isolating one or two pulmonary veins had been performed. The complication was related to pulmonary vein disconnection scars after ablation. Both patients developed new clinical tachycardia (atypical atrial flutter) secondary to a reentrant phenomena in the vicinity of a previously ablated pulmonary vein.     

Esophageal temperature monitoring during radiofrequency ablation of atrial fibrillation

INTRODUCTION: Ablative strategies for atrial fibrillation have centered on the left atrium, in particular the pulmonary veins. An emphasis on ablating outside the ostia of the pulmonary veins appears to have reduced the risk of pulmonary vein stenosis. Unfortunately, ablation in the posterior left atrium has been reported to result in fatal atrio-esophageal fistula. METHODS AND RESULTS: We monitored esophageal temperatures in 16 consecutive patients undergoing atrial fibrillation ablation. There were 14 men and 2 women; average age 54.7 +/- 10.6 years. Eight patients had a lasso-guided pulmonary isolation procedure, eight an electroanatomically guided left-atrial circumferential approach. A commercially available esophageal temperature probe (Mallinckrodt Mon-a-therm 12F Esophageal Stethoscope with Temperature Sensor, Thermistor 400 Series) was positioned under general anesthesia. Temperature changes were noted and related to the relative location of the ablation catheter and the temperature probe during the temperature change. The esophagus was midline in three, right sided in three, and left sided in the remaining patients. Temperature rises could be recorded at the posterior aspect of any pulmonary vein. Detailed analysis of six patient maps revealed heating occurred with lesions created within 1 cm of the esophagus. CONCLUSION: The location of the esophagus relative to the back of the left atrium displays considerable variability. It is rarely midline and most often lies in close proximity to the left-sided veins. Ablation in close radiographic proximity (approximately 1 cm) to the esophagus as defined by a radio-opaque temperature probe can result in heating at the esophageal lumen.     

Acute effects of left atrial radiofrequency ablation on atrial fibrillation

INTRODUCTION: Acutely, when left atrial ablation is performed during atrial fibrillation (AF), the AF may persist and require cardioversion, or it may convert to sinus rhythm or to atrial tachycardia/flutter. The prevalence of these acute outcomes has not been described. METHODS AND RESULTS: Left atrial ablation, usually including encirclement of the pulmonary veins, was performed during AF in 144 patients with drug-refractory AF. Conversion to sinus rhythm occurred in 19 patients (13%), to left atrial tachycardia in 6 (4%), and to atrial flutter in 6 (4%). In the 6 patients with a focal atrial tachycardia, the mean cycle length was 294 +/- 45 ms. The tachycardia arose in the left atrial roof in 3 patients, the left atrial appendage in 2, and the anterior left atrium in 1. In 3 of 6 patients, the focal atrial tachycardia originated in an area that displayed a relatively short cycle length during AF. In 6 patients, AF converted to macroreentrant atrial flutter with a mean cycle length of 253 +/- 47 ms, involving the mitral isthmus in 5 patients and the septum in 1 patient. All atrial tachycardias and flutters were successfully ablated with 1 to 15 applications of radiofrequency energy. CONCLUSION: When left atrial ablation is performed during AF, the AF may convert to atrial tachycardia or flutter in approximately 10% of patients. Focal atrial tachycardias that occur during ablation of AF may be attributable to driving mechanisms that persist after AF has been eliminated, whereas atrial flutter results from incomplete ablation lines.     

射频消融治疗老年房扑房颤患者疗效及安全性的评价

目的展望射频消融治疗老年房扑房颤患者的前景，评价其安全性及疗效。方法回顾3年来在北京大学第一医院进行射频消融的年龄在60～82岁的房扑房颤患者的病例。结果46名患者中1例因不能耐受未能继续消融治疗；20例房扑患者全部消融成功，成功率100％，随访1～30个月无复发；25例房颤患者消融肺静脉78条，以肺静脉电位消失为标准，成功率96％，随访1～30个月，5例复发，成功率80．0％。5例复发患者药物控制心室率；1例出现急性心脏压塞，治疗后好转。将该组并发症的发生率与同期在北京大学第一医院因阵发性室上性心动过速行射频消融的年龄16～60岁组并发症的发生率进行比较，差异无显著性。结论射频消融因其安全性、有效性，对老年患者可明显减少药物副作用，提高生活质量，可成为无禁忌房扑房颤患者的一线治疗方案。     

冷冻球囊消融与射频消融对阵发性心房颤动患者心房重构的影响

目的:比较冷冻球囊消融(CBA)与射频消融(RFA)对阵发性心房颤动(房颤)患者心房重构的影响.方法:本研究选取在2014年5月-2017年5月于郑州大学第一附属医院因阵发性房颤行CBA或RFA治疗的患者.所有患者均于术前、术后半年、1年、2年和3年时行12导联心电图或24 h动态心电图和超声心动图检查.左心房电重构通...     

Intra-operative cooled-tip radiofrequency linear atrial ablation to treat permanent atrial fibrillation.

AIMS: To demonstrate the safety and efficacy of saline irrigated cooled-tip atrial linear endocardial radiofrequency ablation (SICTRA) concomitant to open-heart surgical procedures in the treatment of permanent atrial fibrillation (AF). METHODS AND RESULTS: Two hundred and twenty-two patients presenting with permanent AF and the need for cardiac surgery were included. In addition to the cardio-surgical procedure [mitral valve (MV) surgery (n = 94), aortic valve replacement (n = 29), bypass surgery (n = 76 including 24 patients with additional MV surgery), and combined procedures (n = 23)] concomitant SICTRA was performed. In 116 patients, the ablation pattern was restricted to the left atrium alone. During the mean follow-up of 29 months, 174 patients (78%) converted to sinusrhythm (SR). In patients with SICTRA restricted to the left atrium conversion rates were not different compared to a biatrial approach (83 vs. 74%, P = 0.47). Thirty-days mortality was found to be 4% (9/222). Post-mortem evaluation revealed 23% of all lesions to be histologically non-transmural. In the overall group, only 4% of patients developed sustained secondary regular atrial arrhythmia. CONCLUSIONS: SICTRA safely and effectively restores stable SR in 78% of patients with permanent AF undergoing open-heart surgery. Rhythm outcome is not influenced by treatment of the right atrium. Sustained regular atrial arrhythmia with the need for invasive treatment strategies occurs in 4% although intra-operative ablation lesions are often non-transmural.