经球囊超声消融肺静脉口治疗阵发性心房颤动的临床研究

目的对经球囊超声消融肺静脉口治疗阵发性心房颤动的疗效和安全性进行临床评价。方法阵发性心房颤动患者5例，症状明显且应用抗心律失常药物治疗无效。经球囊超声消融肺静脉的开口，消融终点为肺静脉电学隔离。结果总计消融了19支肺静脉，单纯超声消融肺静脉实现电学隔离15支(73、7％)。早期有1例心房颤动复发，1例频发房性期前收缩，1例偶发房性期前收缩，均经胺碘酮治疗后消失。所有患者的随访时间超过6个月，均可以无需药物而维持窦性心律。并发症包括消融中1例出现心房穿孔，1例出现严重迷走反应，无肺静脉狭窄。结论肺静脉口超声消融是治疗阵发性心房颤动的一种有效手段。     

阵发性心房颤动患者经导管射频消融治疗的护理

目的 探索经导管射频消融治疗阵发性心房颤动患者的护理措施.方法 2005年1月-2006年7月,5例阵发性心房颤动患者经导管行射频消融治疗,前3例采用肺静脉节段性电隔离,后2例采用三维标测系统指导下的环肺静脉线性消融,对其进行密切观察和护理.结果 5例患者即刻成功率100%,2例患者分别于术后1 d、3 d心房颤动复发,5例均无严重并发症发生.结论 做好心理护理,加强迷走神经反射、血栓栓塞、肺静脉狭窄、心包压塞等的观察对提高手术的安全性具有重要的意义.     

经导管射频消融治疗阵发性心房颤动临床研究

[目的]探讨经导管射频消融治疗阵发性心房颤动的有效性与安全性.[方法]60例阵发性心房颤动患者药物治疗无效且反复发作,采用节段性消融肺静脉电隔离术、CARTO和EnSite 3000三维空间标测系统指导下肺静脉电隔离术3种不同的方法进行肺静脉电位经导管射频消融隔离治疗,术后随访3～41个月.[结果]60例患者中42例(70.0%)经消融成功,10例(16.7%)有效,8例(13.3%)失败,无严重并发症;CARTO和EnSite 3000三维空间标测系统指导肺静脉电隔离术可明显减少X线曝光时间.[结论]经导管射频消融治疗局灶性心房颤动是可行的,对大部分患者是有效的.     

阵发性心房颤动患者经导管射频消融治疗的护理

目的探索经导管射频消融治疗阵发性心房颤动患者的护理措施。方法2005年1月-2006年7月,5例阵发性心房颤动患者经导管行射频消融治疗,前3例采用肺静脉节段性电隔离,后2例采用三维标测系统指导下的环肺静脉线性消融,对其进行密切观察和护理。结果5例患者即刻成功率100%,2例患者分别于术后1d、3d心房颤动复发,5例均无严重并发症发生。结论做好心理护理,加强迷走神经反射、血栓栓塞、肺静脉狭窄、心包压塞等的观察对提高手术的安全性具有重要的意义。     

冷冻球囊导管消融治疗阵发性心房颤动病人的护理

[目的]总结冷冻球囊导管消融治疗阵发性心房颤动病人的护理。[方法]对2例阵发性心房颤动病人行冷冻球囊导管消融治疗,同时加强围术期的护理。[结果]2例病人均成功进行了肺静脉隔离,术中、术后无严重并发症发生,恢复良好。[结论]加强阵发性心房颤动病人行冷冻球囊导管消融治疗的围术期护理是手术成功的保证。     

经食管超声在房颤射频消融治疗前后肺静脉血流动力学变化的临床研究

目的 探讨经食管超声在心房纤维性颤动(房颤)射频消融治疗前后肺静脉血流动力学变化.方法 应用经食管超声心动图对分为正常对照组(A组)、阵发性房颤组(B组)、持续性房颤组(C组)、射频消融治疗术后转为窦性心律组(D组)、射频消融治疗术后仍为房颤组(E组)的190例受检者进行研究.结果 B组肺静脉内径在正常范围内,而C组肺静脉内径增宽,射频治疗前后内径变化没有显著的统计学差异;A组与B组的血流速度间没有显著差异,S/D＞1;而C组与A组和B组有显著差异,S2波速度减低,D波速度加快,S/D<1.D组与C组S2波有显著差异,E组与C组无显著的差异.结论 经食管超声心动图对探讨房颤射频消融治疗患者肺静脉内径及血流动力学具有重要的临床意义.     

环肺静脉左心房线性导管射频消融术26例围术期护理

目的:探讨在Ensite NavX三维标测指导下行环肺静脉左心房线性导管射频消融治疗心房颤动患者的围术期护理方法。方法:对26例心房颤动患者在三维标测系统下行环肺静脉左心房线性导管射频消融治疗,并给予精心围术期护理。结果:本组26例心房颤动患者均成功完成环肺静脉电隔离,无一例死亡。其中9例阵发性房颤患者在消融过程中出现房颤,随消融线径完成,8例房颤即刻终止,1例转变成左心房房扑,消融二尖瓣峡部达电位双向阻滞后恢复窦性心律。阵发性房颤手术时间为133～180 min,持续性房颤手术时间为150～265 min,平均手术时间(146.8±27.9)min,X线曝光时间(31.6±11.5)min,放电时间(61.9±15.4)min。1例术中发作TIA,经积极治疗后症状缓解。术后随访6个月,6例复发,其中4例再次消融通过有效放电实现肺静脉电隔离,2例拒绝再次手术。结论:Ensite NavX三维标测指导下行环肺静脉左心房线性导管射频消融治疗心房颤动安全有效,准确、恰当、及时的围术期护理措施是取得良好疗效的重要保障。     

阵发性心房颤动的环肺静脉电隔离单环消融及双环消融术的比较

目的 比较环肺静脉电隔离单环消融和双环消融治疗阵发性心房颤动(简称房颤)的疗效.方法 将40例抗心律失常药治疗无效或出现严重不良反应的阵发性房颤患者,按随机数字表法分为单环消融组和双环消融组,每组20例.单环消融组距肺静脉口0.5 cm作肺静脉单环电隔离线;双环消融组距肺静脉口0.5 cm和1 cm处,分别作肺静脉单环电隔离线.对2组患者手术时间、X线曝光时间,术后6、12个月治愈情况及肺静脉狭窄并发症的发生进行比较.结果 术前2组年龄,房颤发病时间、发作频率,左房内径等比较差异均无统计学意义(均P＞0.05).2组手术时间、术中X线曝光时间比较差异均无统计学意义(均P＞0.05).术后6个月,双环消融组的一次手术治愈率为90％,高于单环消融组的80％(P＜0.05);术后12个月,双环消融组二次手术治愈率为95％,明显高于单环消融组的二次手术治愈率的90％ (P＜0.05).术后6个月2组均未发生肺静脉狭窄.结论 环肺静脉电隔离双环消融治疗阵发性房颤较单环消融效果好.     

超声消融电隔离肺静脉治疗阵发性心房颤动9例

目的　利用美国IBI公司生产的超声消融球囊导管和超声消融发生仪治疗和随访阵发性心房颤动 9例 ,观察疗效和并发症。方法　 9例患者中男性 5例 ,女性 4例 ,平均年龄 (5 4 4± 5 2 )岁。其中 1例为轻度高血压患者 ,其余无明显器质性心血管病病史。阵发性心房颤动病史平均为 (4 3± 3 7)年。全部患者房颤发作频率在每月 3次或以上。经穿间隔卵圆窝置入左 1号Swartz鞘 ,经Swartz鞘送入头端可控大头电极分别送至不同肺静脉 ,直接用大头电极标侧肺静脉肌袖电位或换用A focus电极标侧 ,对存在肌袖电位的肺静脉行超声消融。功率一般为 35～ 4 0瓦 ,温度为 6 0℃ ,每次消融时间为 12 0秒 ,重复至肺静脉电位被隔离或消失 ,但同一肺静脉重复消融不超过 10次。结果　本组完全成功脱离药物治疗 3例 ,发作次数明显减少或少量药物能够维持不发作 2例 ,有 2例完全无效 ,另 2例需要进一步随访。结论　超声消融肺静脉电隔离治疗阵发性心房颤动 ,本组成功率和有效率超过 5 0 % ,无肺静脉狭窄等并发症。     

经皮导管射频消融治疗心房颤动病人的护理

阵发性心房颤动（PAF）是没有器质性心脏病的心房颤动,主要发病机制之一是来自肺静脉肌袖的快速电激动的触发。导管射频消融肺静脉电隔离术是应用射频能量消融诱发心房颤动的异位兴奋灶来根治阵发性心房颤动的一项技术,其疗效已得到临床研究证实,是近年来心房颤动非药物治疗的一项重要进展。由于阵发性心房颤动的异位兴奋灶绝大多数（约90％以上）位于肺静脉,特别是双上肺静脉,使得这一治疗的操作程序有别于其他心律失常的射频消融治疗。且手术时间长,消融部位多,因术中病人往往疼痛明显,有时不能配合手术。     

射频消融与微波消融对离体牛肝作用的实验研究

目的：比较射频消融与微波消融对离体牛肝的作用效果。方法实验分为射频组与微波组,分别使用Cool-tip射频针与冷循环微波刀,均采用单针单次方式消融离体牛肝,比较两组间相同消融时间消融灶纵径、横径及体积。结果消融4、6、8 min,微波组消融灶纵径及体积均大于对应时间射频组消融灶纵径及体积（P＜0.05）,消融10 min,两组消融灶纵径及体积差异均无统计学意义（P＞0.05）;消融4 min,微波消融灶横径大于对应时间射频消融灶横径（P＜0.05）,消融6、8、10 min,两组消融灶横径差异均无统计学意义（P＞0.05）。结论与射频相比较,微波的热效率更高,消融速度更快,但随着消融时间延长,最终两者可取得相近的消融效果。     

临床路径在房颤射频消融术患者中的应用

目的探讨临床路径在房颤射频消融术患者中的应用效果。方法根据现行的诊疗护理内容,制订房颤射频消融术的临床路径表。选择房颤射频消融术患者180例,依据患者入院顺序分成观察组和对照组。对照组患者按常规进行护理和健康教育指导。观察组患者根据临床路径表进行护理,比较两组患者的平均住院日、满意度、并发症等指标的差异。结果观察组患者平均住院日和平均住院费用明显低于对照组(P0.01),患者满意度和健康知识测评结果优于对照组(P0.01),两组术后并发症的发生率比较差异无统计学意义(P0.05)。结论推广临床路径有助于在保证护理质量的前提下,减少患者住院日和住院费用,减轻患者经济压力,提高满意度。     

Tissue temperatures and lesion size during irrigated tip catheter radiofrequency ablation: an in vitro comparison of temperature-controlled irrigated tip ablation, power-controlled irrigated tip ablation, and standard temperature-controlled ablation

The limited success rate of radiofrequency catheter ablation in patients with ventricular tachycardias related to structural heart disease may be increased by enlarging the lesion size. Irrigated tip catheter ablation is a new method for enlarging the size of the lesion. It was introduced in the power-controlled mode with high power and high infusion rate, and is associated with an increased risk of crater formation, which is related to high tissue temperatures. The present study explored the tissue temperatures during temperature-controlled irrigated tip ablation, comparing it with standard temperature-controlled ablation and power-controlled irrigated tip ablation. In vitro strips of porcine left ventricular myocardium were ablated. Temperature-controlled irrigated tip ablation at target temperatures 60 degrees C, 70 degrees C, and 80 degrees C with infusion of 1 mL saline/min were compared with standard temperature-controlled ablation at 70 degrees C and power-controlled irrigated tip ablation at 40 W, and infusion of 20 mL/min. Lesion size and tissue temperatures were significantly higher during all modes of irrigated tip ablation compared with standard temperature-controlled ablation (P < 0.05). Lesion volume correlated positively with tissue temperature (r = 0.87). The maximum recorded tissue temperature was always 1 mm from the ablation electrode and was 67 +/- 4 degrees C for standard ablation and 93 +/- 6 degrees C, 99 +/- 6 degrees C, and 115 +/- 13 degrees C for temperature-controlled irrigated tip ablation at 60 degrees C, 70 degrees C, and 80 degrees C, respectively, and 112 +/- 12 degrees C for power-controlled irrigated tip ablation, which for irrigated tip ablation was significantly higher than tip temperature (P < 0.0001). Crater formation only occurred at tissue temperatures > 100 degrees C. We conclude that irrigated tip catheter ablation increases lesion size and tissue temperatures compared with standard ablation in the temperature-controlled mode at the same or higher target temperatures and in the power-controlled mode. Furthermore, tissue temperature and delivered power are the best indicators of lesion volume during temperature-controlled ablation.     

Monitoring stiffness changes in lesions after radiofrequency ablation at different temperatures and durations of ablation

The variations in the stiffness or stiffness contrast of lesions resulting from radiofrequency (RF) ablation of canine liver tissue at different temperatures and for different ablation durations at a specified temperature are analyzed. Tissue stiffness, in general, increases with temperature; however, an anomaly exists around 80 degrees C, where the stiffness of the lesion is lower than that of the lesion ablated at 70 degrees C. On the other hand, the stiffness increases monotonically with the duration of ablation. Plots illustrating the ratio of mean strains in normal canine liver tissue to mean strains in ablated thermal lesions demonstrate the variation in the stiffness contrast of the thermal lesions. The contrast-to-noise ratio (CNRe) of the lesions, which serves as an indicator of the detectability of the lesions under the different experimental imaging conditions described above, is also presented. The results presented in this paper show that the elastographic depiction of stiffer thermal lesions is better, in terms of the CNRe parameter. An important criterion in the elastographic depiction of RF-ablated regions of tissue is the trade-off between ablation temperature and duration of ablation. Tissue necrosis can occur either by ablating tissue to high temperatures for short durations or to lower temperatures for longer durations. In this paper, we attempt to characterize the elastographic depiction of thermal lesions under these different experimental conditions. This paper provides results that may be utilized by practitioners of RF ablation to decide the ablation temperature and duration, on the basis of the strain images of normal liver tissue and ablated thermal lesions discussed in this paper.     

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)     

MR-guided ablation of head and neck tumors

Interstitial laser-induced thermotherapy (LITT) is a minimally invasive technique for local tumor destruction within solid organs using optical fibers to deliver a high-energy laser to the target lesion. MR imaging is used both for placement of the laser in the tumor and for monitoring progress of thermocoagulation caused by the laser The success of LITT is dependent on the delivery of the optical fibers to the target area, real-time monitoring of the effects of the treatment, and subsequent evaluation of the extent of thermal damage. The key to achieving these objectives is the imaging methods used. The thermosensitivity of certain MR sequences is the key to real-time monitoring, allowing accurate estimation of the extent of thermal damage.     

Atrial fibrillation ablation using a closed irrigation radiofrequency ablation catheter

Background: Catheter ablation is an effective therapy for symptomatic, medically refractory atrial fibrillation (AF). Open‐irrigated radiofrequency (RF) ablation catheters produce transmural lesions at the cost of increased fluid delivery. In vivo models suggest closed‐irrigated RF catheters create equivalent lesions, but clinical outcomes are limited. Methods: A cohort of 195 sequential patients with symptomatic AF underwent stepwise AF ablation (AFA) using a closed‐irrigation ablation catheter. Recurrence of AF was monitored and outcomes were evaluated using Kaplan–Meier survival analysis and Cox proportional hazards models. Results: Mean age was 59.0 years, 74.9% were male, 56.4% of patients were paroxysmal and mean duration of AF was 5.4 years. Patients had multiple comorbidities including hypertension (76.4%), tobacco abuse (42.1%), diabetes (17.4%), and obesity (mean body mass index 30.8). The median follow‐up was 55.8 weeks. Overall event‐free survival was 73.6% with one ablation and 77.4% after reablation (reablation rate was 8.7%). Median time to recurrence was 26.9 weeks. AF was more likely to recur in patients being treated with antiarrhythmic therapy at the time of last follow‐up (recurrence rate 30.3% with antiarrhythmic drugs, 13.2% without antiarrhythmic drugs; hazard ratio [HR] 2.2, 95% confidence interval [CI] 1.1–4.4, P = 0.024) and in those with a history of AF greater than 2 years duration (HR 2.7, 95% CI 1.1–6.9, P = 0.038). Conclusions: Our study represents the largest cohort of patients receiving AFA with closed‐irrigation ablation catheters. We demonstrate comparable outcomes to those previously reported in studies of open‐irrigation ablation catheters. Given the theoretical benefits of a closed‐irrigation system, a large head‐to‐head comparison using this catheter is warranted. (PACE 2012; 35:506–513)