经球囊超声导管消融对肺静脉的电隔离作用——附一只犬的动物实验报告

试研究球囊超声导管消融能否电隔离肺静脉、是否造成肺静脉的急性或者慢性狭窄。报告 1只犬的左上肺静脉经球囊超声导管消融电隔离结果。经房间隔将球囊超声导管的球囊置于左上肺静脉与左房的交界处 ,消融至电隔离。消融前后行肺静脉造影检查 ,2个月后行病理检查。结果 :消融开始至隔离的时间为 1160s。有效消融表现为肺静脉内的A波振幅逐渐降低 ,SP间期的逐渐延长至出现肺静脉与心房的电隔离。消融前与消融后 15min的造影对比 ,无肺静脉的狭窄及血液动力学变化。 2个月后尸体解剖发现肺静脉壁的轻度环行增厚 ,无左上肺静脉的狭窄。结论 :球囊超声消融可完全电隔离肺静脉 ,不造成肺静脉的急性或慢性狭窄 ,但长期效果仍有待观察。     

经球囊导管超声消融腔静脉的电隔离作用

Ｌｅｓｈ等报道了用经球囊超声消融 (ｔｈｒｏｕｇｈ ｔｈｅ ｂａｌｌｏｏｎｕｌ ｔｒａｓｏｕｎｄａｂｌａｔｉｏｎ ,ＴＴＢ ＵＳＡ)犬和猪的肺静脉开口的试验结果。本实验用经球囊超声能量消融腔静脉 ,观察是否造成腔静脉的电隔离作用以及是否引起腔静脉的狭窄 ,并寻找 1种研究大静脉电隔离作用及狭窄的模型。　　资料和方法　成年杂种犬 2条 ,雌雄各 1,体重分别为13ｋｇ和 18ｋｇ。用硫喷妥钠 2 5～ 30ｍｇ/ｋｇ腹腔注射麻醉。(1)以 12ｍｌ/ｓ的速度注射 6 0 %泛影葡胺 2 0ｍｌ行上腔或下腔静脉造影 ;(2 )电生理检查 ;(3)消融隔离上腔或…     

导管射频右房线性消融治疗阵发性心房颤动

报道导管射频右房双线性消融临床试验性治疗阵发性心房颤动 (简称房颤 )的结果。10例特发性房颤的患者接受治疗 ,用 8mm大头电极温控导管完成下腔静脉口至三尖瓣口的线性消融 ,用连续 4个大头电极的温控导管完成从下腔静脉口经界嵴至上腔静脉口的线性消融。术中及术后无 1例发生并发症 ,术后恢复过程无异于一般的导管射频消融术。术后随访 1～ 10月 ,其中 6例无房颤发作、2例房颤发作次数明显减少 ;此 8例中 ,6例在术中诱发房颤时房颤是由 b型心房扑动转变而来。另 2例房颤发作次数无明显变化。初步结果表明 :导管射频右房双线性消融对 b型心房扑动启动的阵发性房颤有较好的治疗效果 ,但仍需积累更多病例和做更长时间的观察。     

入心静脉口环状超声消融动物实验

观察入心静脉口环状超声消融对心电传导及影像学的影响 ,探讨超声消融在治疗局灶源性心房颤动 (简称房颤 )中的临床价值。选用健康成年杂种犬 7只 ,用特制的超声球囊导管和温控大头导管在S1S1快速刺激下分别环状消融肺静脉口和上、下腔静脉口。超声消融时预设温度 60℃、功率 2 0W、脉宽 15ms,3 0 %输出方式 ;若放电 10s后温度达不到 5 0℃ ,则加大功率、脉宽或输出方式 ,直至达到有效消融温度 ( 5 5℃以上并持续 3 0s以上 ) ;观察消融前后心电传导的变化及管腔形态的变化。结果 :共超声消融入心静脉口 10个 ,除一个上腔静脉口因管腔直径过大只在放电时引起一过性电隔离外 ,其余 9个超声消融后都可造成持久的电隔离 ,且未见急性狭窄 ;而 7个射频消融的入心静脉口无一例形成持久的电隔离 ,且有 4例发生急性狭窄。结论 :超声消融更易在入心静脉口形成完全、持久的电隔离 ,很少导致管腔狭窄 ,且操作简单 ,安全可靠 ,优于射频消融。     

心房颤动经导管消融治疗方法的历史演变概述

上世纪90年代以来,心房颤动(简称房颤)经导管消融治疗方法学发展大致经历了5个阶段:①模仿迷宫术(MAZE)的导管射频消融术;②线性消融术;③点消融术;④肺静脉电隔离术;⑤解剖指导下的肺静脉口环状消融术,这反映了关于房颤机制认识不断深入的过程。     

超声消融与射频消融对纤溶系统影响的实验研究

将健康成年杂种犬11只随机分成两组，观察组5只行上、下腔静脉口超声消融，对照组6只行上、下腔静脉口射频环状消融。分别于插管前，插管后，消融后即刻，消融后0．5h、48h取外周静脉血5ml，用发光底物法测定组织型纤溶酶原激活剂（t-PA）及t-PA抑制物1（PAI-1）的变化。结果两组t-PA、PAI-1插管前后无明显变化；t-PA于消融后即刻达高峰，0．5h后开始下降；PAI-1于消融后0．5h达高峰，消融后48h恢复正常，两组比较。t-PA无明显差异，但PAI-1在消融后即刻及消融后0．5h，对照组明显高于观察组。证实超声消融与射频消融均—过性激活纤溶系统，其对凝血系统的激活占优势，且射频消融更明显，超声消融入心静脉口不易形成血栓，较射频消融更为安全。     

导管迷宫射频消融治疗心房颤动的研究

为探索导管迷宫射频电消融（MPRFCA）治疗心房颤动（房颤）的方法，随机选择7条犬，正中线开胸后在右心房外膜上放置5％氯化乙酰胆碱小棉球，1min后用无齿镊轻夹心房诱发持续性房颤（持续时间＞20min），所有犬MPRFCA术前房颤平均持续1516±509s。参考外科迷宫术设计MPRFCA靶图，在双侧心房的5个部位用射频能量（30W，持续30s）产生彼此分离的5条线性透壁性损伤，每条犬完成MPRFCA分割后重复用乙酰胆碱诱发房颤，其持续时间明显缩短（平均324±209s），与术前比较差异有极显著意义。提示MPRFCA术可明显缩短房颤的持续时间，消除持续性房颤的发生。     

经皮导管冷冻消融治疗阵发性心房颤动的临床应用

目的:探讨导管冷冻消融术治疗心房颤动的有效性及安全性.方法:对12例阵发性心房颤动患者进行冷冻消融治疗.评价导管冷冻消融术治疗心房颤动的急性成功率、术后并发症以及临床长期有效性.结果:12例阵发性心房颤动患者,共对44根肺静脉进行了冷冻消融,其中29根肺静脉单用环状冷冻导管消融4～6次即能达到肺静脉的完全电隔离,15根肺静脉用环状冷冻导管消融后,需用普通射频消融导管在环形冷冻线上补点消融后才成功隔离肺静脉.随访6～10个月,9例临床症状得到改善,无心房颤动复发,其中3例需服用抗心律失常药维持窦性心律.3例患者心房颤动复发.消融后即刻选择性肺静脉造影和术后6个月核磁共振扫描检查均未发现肺静脉狭窄.结论:经皮导管冷冻消融治疗阵发性心房颤动是安全、有效的,可作为治疗心房颤动的一种有效方法.     

直视下心外膜导管射频消融右侧房室旁路

目的对右侧房室旁路合并需要进行外科手术治疗的心脏病患者,或多次心内膜导管射频消融治疗失败者,探讨采用直视下心外膜导管射频消融法阻断房室旁路传导的可能性。方法３例右侧显性房室旁路,２例为男性慢性风湿性二尖瓣病变,术前经多家医院心内膜导管射频消融术治疗均未成功,旁路分别位于右房室环９点和７点处;１例为女性先天性心脏病室间隔缺损,术前未经导管射频消融治疗,体表心电图定位旁路位于右侧前壁。手术中于右房和右室外膜各缝扎一根２极导管用于双极记录和刺激,手执四极大头电极导管沿右侧房室沟从室间隔处经右游离壁到冠状静脉窦口或反向进行标测,在理想的标测靶点处放电消融。结果３例患者的３条旁路均一次消融成功,没有心房穿孔或右冠状动脉损伤等并发症,旁路阻断时间１～２ｓ,总操作时间１０～２０ｍｉｎ,术后随访６～１２个月无心动过速复发。结论对右侧房室旁路合并需要进行手术治疗的心脏病患者或多次心内膜导管射频消融治疗失败者,可考虑采用心外膜导管射频消融的方法进行治疗。     

心外膜射频消融治疗心房颤动的实验研究

为探索心房颤动（ＡＦ）心外膜消融简便方法，选用健康犬及二尖瓣关闭不全模型犬各５只，应用自制线形射频电极沿左、右心耳根部，左房顶部，右心耳根部至下腔静脉根部连线及横跨界沟的线路行心外膜线形消融，同时经冠状静脉窦导管电极消融冠状静脉窦远端。开胸前、关胸后及术后２～５周分别测定ＡＦ诱发率（快速心房起搏、持续静脉滴注乙酰胆碱的条件下）、校正窦房结恢复时间（ＣＳＮＲＴ）、窦率－异丙肾上腺素反应性及高位右房有效不应期（ＨＲＡ－ＥＲＰ）。结果：与术前相比，关胸后及术后２～５周均不能诱发ＡＦ，ＣＳＮＲＴ、ＨＲＡ－ＥＲＰ无变化（Ｐ均＞０．０５），窦率－异丙肾上腺素反应性不降低（Ｐ均＞０．０５）。术后２～５周超声心动图显示心房运动正常、无血栓形成。病理检查证实射频消融区透壁性损伤，而窦房结无损伤。结果表明在心外膜按一定路线射频消融治疗ＡＦ是可行的。     

Initial Experience with a Novel Focused Ultrasound Ablation System for Ring Ablation Outside the Pulmonary Vein

Introduction: Atrial fibrillation has been shown to initiate from triggers within pulmonary veins. Several studies have documented that electrical isolation of those triggers can lead to maintenance of sinus rhythm. The complication of pulmonary vein stenosis has limited the utility of delivering ablation energy within the pulmonary vein. We utilize a focused ultrasound catheter ablation system for delivery of transmural ablation lines proximal to the pulmonary vein ostium. Methods: Nine dogs (weight 30–39 kg) were anesthetized and ventilated. Through a transseptal approach, pulmonary veins were engaged with the focused balloon ultrasound catheter. Ultrasound power was delivered at 40 acoustic watts outside the pulmonary vein ostium, focused 2 mm off the balloon surface, with a depth of approximately 6 mm, for 30–120 seconds. Following ablation, lesions were histopathologically analyzed. Results: Of nine animals studied, fourteen pulmonary veins were ablated. We found successful delivery of near circumferential and transmural ablation lines in 6/14 pulmonary veins. In each of the six circumferential ablations, successful alignment of the ultrasound transducer along the longitudinal axis of the parabolic balloon occurred. The final four ablations were conducted with an enhanced catheter design that assured axial alignment. Of these ablations, all four were circumferential. The remaining 8 pulmonary veins had incomplete delivery of lesions. In each of these veins the ultrasound transducer was misaligned with the balloon axis when therapy was delivered. Conclusion: Focused ultrasound ablation is a new means of performing pulmonary vein isolation. This method provides delivery of lesions outside the vein, limiting the risk of pulmonary vein stenosis for the treatment of atrial fibrillation.     

Parahisian Radiofrequency Catheter Ablation in Dogs: Comparison of the above-valve and below-valve approaches

In patients with an accessory pathway close to the His bundle, radiofrequency catheter ablation (RFCA) requires additional care to avoid damage to the normal conduction system. To assess differences between approaches from above or below the tricuspid valve (TV), we performed RFCA in 20 dogs (from above, group A, n=10; from below, group B, n=10). RF energy with temperature control at 60° 60 seconds was administered at the site where a small His potential was recorded from the ablation catheter guided by fluoroscopy and transesophageal echocardiography (TEE) (in the latter six dogs). Before and after RFCA, electrophysiological testing was performed and histological findings were compared. An ablated lesion was created in 7 of 10 (2 of 2 guided by TEE) dogs in group A and 5 of 10 (3 of 4 TEE) dogs in group B. In group A, an ablated lesion involved the atrium and ventricle in the anterior site of His bundle, but the lesion was only in the ventricle in group B. An atrioventricular block (AVB) and severe damage to the penetrating bundle was observed in one dog of group A. A large hematoma on the TV was made in 2 dogs and the complete right bundle branch block (CRBBB) occurred in 3 dogs of group B. The approach from below the TV was safer than that from above the TV in parahisian RFCA, because it did not create an AVB, although it has a high incidence of CRBBB and associated technical difficulties.     

通过动物实验评价射频能量对冠状动脉的急性损伤

目的通过动物实验观察射频消融术(RFCA)是否会导致冠状动脉(简称冠脉)的急性损伤,对比不同的消融方法对冠脉的影响。方法取成年犬21只,雌雄不限,随机分三组,第一组消融电极为4mm,能量级别设定为60℃/120s,分别消融左房室环、右房室环、冠状静脉窦内和心外膜的近冠脉处;第二组能量级别设定为80℃/120s,分别消融除心外膜外的其它三处;第三组消融电极为8mm,能量级别设定为60℃/120s,仅消融左右房室环。术毕观察消融点附近冠脉损伤情况,并取消融点及附近冠脉作病理检查,光镜下观察心肌和冠脉的变化。结果大体下观察,没有发现冠脉管腔的狭窄及管腔内血栓形成。对63处消融点附近的冠脉进行光镜检查时,3例冠脉或其分支出现明显变化,动脉壁破裂、壁结构消失、平滑肌溃疡、变性坏死,溃疡内有大量白细胞浸润;9例冠脉内皮细胞出现肿胀、脱落甚至消失;其余冠脉未有任何变化。结论常规RFCA是安全可靠的,但特殊部位、高能量射频消融时,应注意冠脉的损伤。     

Radiofrequency Catheter Ablation of the Left Bundle Branch in a Canine Model

Left Bundle Branch Ablation. Introduction: Transcatheter ablation of the left bundle branch may be considered for management of selected macroreentrant ventricular tachycardias. Left bundle ablation can also change the sequence of left ventricular contraction and may simulate pacing in hypertrophic obstructive cardiomyopathy. The purpose of this study was to determine electrophysiologic and anatomic parameters for successful selective transcatheter left bundle ablation in a canine model. Methods and Results: A catheter was advanced to the left ventricular apex and the tip deflected toward the septum, until a discrete left bundle potential (LBP) was found. Radiofrequency (RF) energy was then applied until left bundle branch block or complete AV block occurred. In 29 (85%) dogs, an LBP (mean LBP-V 16 ± 3 msec; range 10 to 20 msec) was identified resulting in successful left bundle ablation. In 5 (15%) dogs, a similar potential (mean potential-V 28 ± 4 msec; P = 0.001 vs LBP-V) was identified, but RF energy application produced complete AV block. The A:V electrogram ratio at the successful LBP ablation site was < 1:10 in all 29 dogs successfully ablated, but only 2 (40%) of 5 dogs in the unsuccessful group (P = 0.0017). In 4 successfully ablated dogs, the right bundle potential was mapped and complete AV block was created by RF energy application, confirming that the left bundle was completely ablated. In 9 dogs, the left bundle and AV junction were sequentially ablated with 1 lesion at each site. Postmortem examination showed 2 discrete lesions 1.2 ± 0.7 cm apart. Conclusions: Selective transcatheter left bundle ablation was successfully guided by the LBP. The distance between the AV junction and the main left bundle was 1.2 cm in this canine model. An A:V ratio < 1:10 and an LBP-V time < 20 msec appear to minimize the risk of AV block. Prudent use of similar techniques may cure macroreentrant ventricular tachycardias and reduce the need for permanent pacing in hypertrophic obstructive cardiomyopathy.     

不同温度超声消融肺静脉口对电传导影响的实验研究

观察不同温度超声消融肺静脉口对电传导的影响 ,探索适合肺静脉口的最佳超声消融温度。选用健康成年犬 15只 ,随机分为 5 0℃、5 5℃及 6 0℃消融组 ,用特制的超声球囊导管在S1S1快速起搏下环状消融肺静脉口 ,观察产生电隔离的时间及消融后每隔 10min再次快速起搏观察电隔离是否存在。结果 :共消融肺静脉口 5 1个 ,实验发现 ,在消融温度为 5 0℃时 ,所有消融处均未产生电隔离 ;在消融温度为 5 5℃时多产生一过性电隔离 ;在消融温度为6 0℃时可产生有效电隔离消融温度为 6 0℃时 ,电隔离多发生在达到预设消融温度后 10s内 ,最长发生在达到预设消融温度后 2 2s。结论 :经球囊超声消融肺静脉口 ,在消融温度达到 6 0℃ ,持续 30s能够产生有效电隔离。     

A novel mesh electrode catheter for mapping and radiofrequency delivery at the left atrium-pulmonary vein junction: a single-catheter approach to pulmonary vein antrum isolation

Background: Electrical isolation of pulmonary veins (PV) by radiofrequency (RF) ablation is often performed in patients with atrial fibrillation (AF). Current catheter technology usually requires the use of a multielectrode catheter for mapping in addition to the ablation catheter.
Purpose: We evaluated the feasibility and safety of using a single, expandable electrode catheter (MESH) to map and to electrically isolate the PV.
Methods and Results: Nineteen closed-chest mongrel dogs, weighing 23–35 kg, were studied under general anesthesia. Intracardiac echocardiography (ICE) was used to guide transseptal puncture and to assess PV dimensions and contact of the MESH with PV ostia. ICE and angiography of RSPV were obtained before and after ablation, and prior to sacrifice at 7–99 days. An 11.5 Fr steerable MESH was advanced and deployed at the ostium of the RSPV. Recordings were obtained via the 36 electrodes comprising the MESH. For circumferential ablation, RF current was delivered at a target temperature of 62–65°C (4 thermocouples) and maximum power of 70–100 W for 180 to 300 seconds. Each animal received 1–4 RF applications. Entrance conduction block was obtained in 13/19 treated RSPVs. Pathological examination confirmed circumferential and transmural lesions in 13 of 19 RSPV. LA mural thrombus was present in 3 animals. There was no significant PV stenosis.
Conclusion: Based on this canine model, a new expandable MESH catheter may safely be used for mapping and for PV antrum isolation. This approach may decrease procedure time without compromising success rate in patients undergoing AF ablation.     

心房内膜射频消融治疗心房颤动的实验研究

为探索心房内膜标测指导射频消融治疗心房颤动 (AF)的可行性 ,选实验犬 16只 ,对右心房行心内膜标测并在其指导下消融 (右房和双房消融组各 8只 )。与术前相比 ,在同等条件下 ,消融后不能诱发或仅可诱发短阵AF ,但无一次持续时间超过 1min者视为手术成功。右房消融组中 ,对标测出关键部位 (电激动最无序、ff间期最短、最早出现f波及导管刺激易诱发AF的部位 )的 5只犬 ,行纵向跨间隔的单径线消融 ,成功 3例、失败 2例 ;对关键部位不典型的 3只犬行双径线消融 ,成功 1例、失败 2例。双房消融组中 ,关键部位位于房间隔的 4只犬行单径线消融 +左房肺静脉口局灶性消融全部成功 ;关键部位位于右心房侧壁上部的 1只犬行双径线消融 +左房肺静脉口局灶性消融后也获成功 ;关键部位不典型的 3只犬行双径线消融 +左房肺静脉口局灶性消融 ,1例成功、2例失败。消融前后基础电生理参数无明显变化 (P <0 .0 5 )。结果初步表明经导管心房内膜射频消融治疗AF是可行的 ,且心内膜标测对消融方案的选择具有指导性     

肺静脉内不同温度射频消融对血液动力学的影响

探讨用不同预置温度行肺静脉内射频消融对血液动力学的影响。选择健康杂种犬 3 0只 ,分成 5 0℃ ,60℃ ,70℃三组 ,经房间隔途径将温控电极置入肺静脉内进行消融 ,消融时间均为 60s。消融前、消融后即刻监测心电图 ,行选择性肺静脉造影 ,并测量右房压 (RAP)、右室压 (RVP)、主肺动脉压 (PAP)、左房压 (LAP)。术后留养 3个月 ,重复以上检查。结果 :5 0℃组 1只犬在行房间隔穿刺时因心包填塞死亡 ,其余均顺利完成试验。共在 72处肺静脉内行点状消融 ,5 0℃、60℃、70℃组分别为 2 0 ,2 6,2 6处。右上、下肺静脉 ,左上、下肺静脉分别为 13 ,9,2 7,2 3处。 5 0℃及 60℃组消融后即刻、术后 3个月血液动力学指标无显著变化 ;70℃组消融后即刻、术后 3个月肺动脉压分别为 3 5± 7,3 3± 5mmHg,较术前 ( 2 8± 4mmHg)明显升高 (P <0 .0 5 ) ;左房压分别为 11± 4 ,12± 2mmHg ,较术前 ( 14± 3mmHg)显著降低 (P <0 .0 5 ) ;70℃组肺静脉狭窄的发生率均明显高于 60℃组及 5 0℃组。结论 :肺静脉内射频消融影响血液动力学的原因主要是肺静脉狭窄 ;消融温度在 60℃和 70℃之间存在影响血液动力学的临界值 ,故预置温度应控制在 60℃以内。     

Catheter Ablation of Wolff-Parkinson-White Syndrome Associated with Congenital Absence of Inferior Vena Cava

In the present report we describe a patient (a 36-year-old woman with 15 year history of supraventricular tachyarrhythmias) with congenital absence of inferior vena cava (IVC) revealed during radiofrequency (RF) catheter ablation procedure for right postero-septal Wolff-Parkinson-White syndrome (WPW). For the absence of IVC, the ablation procedure was more difficult, because we had to perform the ablation with the catheters (the ablator catheter and the coronary sinus catheter) introduced both through the superior vena cava. The application of RF energy (35 Watt for 60 seconds) at successful site abolished accessory pathway conduction. The following day was performed the venous angiography, showing the absence of the IVC and a venous return via paravertebral venous plexus to the azygous vein and superior vena cava into the right atrium. Computer tomography confirmed the absence of the IVC with azygous continuation. The drainage via the azygous system modified the radiological image on chest roentgenogram of the right mediastinal silhouette. During cardiogenesis fusion of the IVC and organisation of the heart occur between the 33rd to 40th embryonic days. It is therefore possible that some unknown teratogenic mechanism at this critical period might have caused, in the patient, both the developmental arrest of IVC and failure of regression of atrio-ventricular anatomical and electrical continuity in the right postero-septal region.