Cryoballoon ablation versus radiofrequency ablation for atrial fibrillation

Catheter ablation (CA) provides the most effective treatment option for patients suffering from symptomatic atrial fibrillation (AF). The procedural cornerstone of all ablation strategies and for all entities of AF is the electrical isolation of the pulmonary veins (PV). CA with the use of radiofrequency (RF) in conjunction with a 3-dimensional electroanatomical mapping system is the most established ablation approach, but it demands a long learning curve and recurrences of AF are commonly the result of recovered PV conduction. As a consequence, novel ablation systems such as the Cryoballoon (CB) have been evolved aiming at facilitation and increased efficacy of pulmonary vein isolation (PVI). CB ablation is characterized by a short learning curve as well as short procedure times and demonstrated non-inferiority with regard to safety and efficacy when being directly compared to RF ablation for treatment of paroxysmal AF. However, RF ablation is first choice for treatment of persistent AF, in particular when expanded ablation strategies beyond PVI are intended in order to improve clinical outcomes.     

Catheter ablation

Catheter ablation is gaining increasing interest for the therapy of symptomatic, sustained arrhythmias of various origins. The scope of this review is to give an overview of the biophysical aspects and major characteristics of some of the most widely used energy sources in catheter ablation, e.g., the discharge of conventional defibrillators, modified defibrillators, laser light, and radiofrequency current application. Results from animal studies are considered to explain the basic mechanisms of catheter ablation. The recent achievements with the use of radiofrequency current to modify or ablate cardiac conduction properties are outlined in more detail.     

Radiofrequency ablation during continuous saline infusion can extend ablation margins

AIM:To determine whether fluid injection during radiofrequency ablation(RFA) can increase the coagulation area.METHODS:Bovine liver(1-2 kg) was placed on an aluminum tray with a return electrode affixed to the base,and the liver was punctured by an expandable electrode.During RFA,5% glucose;50% glucose;or saline fluid was infused continuously at a rate of 1.0 mL/min through the infusion line connected to the infusion port.The area and volume of the thermocoagulated region of bovine liver were determined after RFA.The Joule heat generated was determined from the temporal change in output during the RFA experiment.RESULTS:No liquid infusion was 17.3 ± 1.6 mL,similar to the volume of a 3-cm diameter sphere(14.1 mL).Mean thermocoagulated volume was significantly larger with continuous infusion of saline(29.3 ± 3.3 mL) than with 5% glucose(21.4 ± 2.2 mL),50%glucose(16.5 ± 0.9 mL) or no liquid infusion(17.3 ± 1.6 mL).The ablated volume for RFA with saline was approximately 1.7-times greater than for RFA with no liquid infusion,representing a significant difference between these two conditions.Total Joule heat generated during RFA was highest with saline,and lowest with 50% glucose.CONCLUSION:RFA with continuous saline infusion achieves a large ablation zone,and may help inhibit local recurrence by obtaining sufficient ablation margins.RFA during continuous saline infusion can extend ablation margins,and may be prevent local recurrence.     

Atrial fibrillation ablation

Atrial fibrillation is the commonest cardiac arrhythmia, with significant morbidity related to symptoms, heart failure, and thromboembolism, which is associated with excess mortality. Over the past 10 years, many centers worldwide have reported high success rates and few complications after a single ablation procedure in patients with paroxysmal atrial fibrillation. Recent studies indicate a short-term and long-term superiority of catheter ablation as compared with conventional antiarrhythmic drug therapy in terms of arrhythmia recurrence, quality of life, and arrhythmia progression. As a result, catheter ablation is evolving to a front-line therapy in many patients with atrial fibrillation. However, in patients with persistent long-standing atrial fibrillation catheter ablation strategy is more complex and time-consuming, frequently requiring repeat procedures to achieve success rates as high as in paroxysmal atrial fibrillation. In the near future, however, with growing experience and evolving technology, catheter ablation of atrial fibrillation may be extended also to patients with long-standing atrial fibrillation.     

透壁消融指数在阵发性心房颤动消融术中的应用价值分析

目的探讨透壁消融指数(LSI)在阵发性心房颤动(PAF)消融术中的应用价值。方法选择住院治疗的PAF患者96例,随机分为对照组50例和观察组46例(采用光感应压力导管进行消融,对患者LSI设定)。比较分析2组临床资料、术后6个月内PAF复发率、并发症发生率及PAF患者消融术成功的因素。结果观察组与对照组手术时间和并发症发生率无显著差异(P0.05);观察组X线透视时间[(23.1±6.8)min vs (36.4±7.2)min]和PAF复发率(10.9%vs 30.0%)明显低于对照组,差异有统计学意义(P0.05);肺静脉单圈隔离率明显高于对照组(89.1%vs 50.0%,P0.01);LSI参数设定是PAF患者消融手术成功的独立影响因素(OR=2.792,95%CI:0.835～134.653,P=0.004)。结论 LSI参数设定能够提高肺静脉电位隔离率、降低X线透视时间、PAF复发率,是PAF患者消融手术成功的独立影响因素。     

射频消融术

导管射频消融术(ＲＦＣＡ)是十几年来发展很快的治疗快速性心律失常新技术,其治疗范围与适应证也不断扩大。它对电生理学家们提出了更高的要求和严峻的挑战,要求他们在短时间内对心动过速作出正确的诊断,熟练掌握导管操作技术和心脏的解剖结构等。我院自1990年成功地进行1例预激综合征射频消融治疗,至今已完成1800余例各种快速性心律失常的ＲＦＣＡ治疗。据此,本文将就目前ＲＦＣＡ治疗方法作一介绍。1　各种快速性心律失常ＲＦＣＡ适应证见1996年射频导管消融治疗快速心律失常指南[1]。2　房室折返性心动过速　　房室折返性心动过速(ＡＶＲ…     

慢性心房颤动导管消融:碎裂电位消融和线性消融的比较

目的评价环肺静脉隔离(CPVI)基础上采用心房碎裂电位(CFAEs)消融或(和)线性(Linear)消融进行心房基质改良的疗效。方法回顾性分析156例慢性心房颤动(简称房颤)消融病例,房颤病程2.5±2.3年,左房内径42.4±4.5 mm。根据消融术式改进分为三组CPVI+CFAEs、CPVI+linear和CPVI+CFAEs+Linear组。比较消融术中房颤终止比例及随访疗效。结果三组消融总时间有显著性差异(160±14 min vs 178±9 min vs 241±8min,P<0.01)。CPVI+CFAEs组终止房颤/转变房性心动过速(简称房速)的比例(52.7%)显著高于CPVI+Line-ar组(18.4%),但低于CPVI+CFAEs+Linear组(73.1%)。术后3.1±1.2个月,三组二次消融比例47.3%、51%、38.5%,P=0.43。术后平均随访9.5±1.8个月,三组无房性快速性心律失常复发例数分别为39例(70.9%)、33例(67.3%)和41例(78.8%),P=0.41(服用抗心律失常药物比例25.6%、24.2%和22%,P=0.96)。结论 CP-VI基础上CFAEs消融的房颤终止比例高于单纯线性消融,但低于联合应用CFAEs消融和Linear消融。尽管如此,三组术后二次消融比例和随访成功率无显著性差异。     

消融指数指导下高功率消融在老年心房颤动患者中的应用效果

目的 探讨消融指数指导下高功率消融在老年心房颤动(房颤)患者中的有效性和安全性.方法 选取2019年1月～2021年1月于山西医科大学第一医院行高功率(45 W)消融的老年房颤患者50例为高功率组,另选常规功率消融(35W)50例患者为常规功率组,2组相同消融指数指导消融.消融终点为双侧肺静脉隔离,比较2组手术相关参数...     

Radiofrequency catheter ablation of common atrial flutter: Comparison of electrophysiologically guided focal ablation technique and linear ablation technique

Objectives. The purpose of this study was to study electrophysiologic characteristics and compare the electrophysiologically guided focal ablation technique and linear ablation technique in patients with common atrial flutter in a prospective randomized fashion.Background. Catheter ablation of the common atrial flutter circuit can be performed with different techniques. To date, these two techniques have not been compared prospectively in a randomized study.Methods. Sixty patients with drug-refractory common atrial flutter were randomly assigned to undergo radiofrequency catheter ablation performed with the electrophysiologically guided focal ablation (Group I) or linear ablation technique (Group II). In Group I, radiofrequency energy was delivered to the site characterized by concealed entrainment with a short stimulus-P wave interval (<40 ms) and a postpacing interval equal to the atrial flutter cycle length. In Group II, continuous migratory application of radiofrequency energy was used to create two linear lesions in or around the inferior vena cava-tricuspid ring isthmus. Serial 24-h ambulatory electrocardiographic (Holter) and follow-up electrophysiologic studies were performed to assess recurrence of tachycardia and possible atrial arrhythmogenic effects.Results. Successful elimination of the flutter circuit was achieved in 28 of 30 patients in Group I and 29 of 30 patients in Group II. More atrial premature beats and episodes of short run atrial tachyarrhythmias in the early period (within 2 weeks) after ablation were found in Group II. Recurrence rate (2 of 28 vs. 3 of 29) and incidence of new sustained atrial tachyarrhythmias (3 of 28 vs. 3 of 29) was similar in the two groups. Occurrence of recurrent atrial flutter and new sustained atrial tachyarrhythmias was related to associated cardiovascular disease and atrial enlargement in both groups. However, in Group II, the procedure time (104 ± 17 vs. 181 ± 29 min, p < 0.01) and radiation time (22 ± 8 vs. 42 ± 13 min, p < 0.01) were significantly shorter than those in Group I.Conclusions. Radiofrequency ablation of the common atrial flutter circuit was safe and effective with either the electrophysiologically guided focal ablation or linear ablation technique. However, the linear ablation technique was time-saving.     

Percutaneous microwave ablation vs radiofrequency ablation in the treatment of hepatocellular carcinoma

Hepatocellular cancer ranks fifth among cancers and is related to chronic viral hepatitis, alcohol abuse,steatohepatitis and liver autoimmunity. Surgical resection and orthotopic liver transplantation have curative potential, but fewer than 20% of patients are suitable candidates. Interventional treatments are offered to the vast majority of patients. Radiofrequency(RFA) and microwave ablation(MWA) are among the therapeutic modalities, with similar indications which include the presence of up to three lesions, smaller than 3 cm in size, and the absence of extrahepatic disease. The therapeutic effect of both methods relies on thermal injury, but MWA uses an electromagnetic field as opposed to electrical current used in RFA. Unlike MWA, the effect of RFA is partially limited by the heat-sink effect and increased impedance of the ablated tissue. Compared with RFA, MWA attains a more predictable ablation zone, permits simultaneous treatment of multiple lesions, and achieves larger coagulation volumes in a shorter procedural time. Major complications of both methods are comparable and infrequent(approximately 2%-3%), and they include haemorrhage, infection/abscess, visceral organ injury, liver failure, and pneumothorax. RFA may incur the additional complication of skin burns. Nevertheless, there is no compelling evidence for differences in clinical outcomes, including local recurrence rates and survival.