A Decrease in Pulmonary Vein Diameter After Radiofrequency Ablation Predicts the Development of Severe Stenosis

A decrease in ostial pulmonary vein (PV) diameter was observed in patients on the day after radiofrequency ablation of atrial fibrillation (AF). This study examined whether a relative reduction in PV diameter on day 1 (RRPVD1) after the procedure predicts the late development of severe PV stenosis (PVS). The study included 104 consecutive patients (mean age = 55 years, range 46–61, 34 women) with drug refractory AF. Pulmonary vein diameter was measured using MR angiography (MRA) on the day before and on day 1 after the ablation procedure. The MRA was repeated every 3 months after the procedure. Severe PVS was defined as a >70% diameter reduction from the initial ostial diameter. The cut-off of RRPVD1 was prespecified as 25% decrease in initial diameter. The data are presented as medians and interquartile range. A total of 357 PV were treated. The RRPVD1 was 0.0% (0.0–11.1%). Severe PVS was found in 18 PV during a follow-up of 12 months (range 6–13). The log-rank analysis confirmed a strong association between a RRPVD1 ≥25% and the development of PVS (hazard ratio: 7.1; 95% confidence interval 3.8–13.5, P < 0.0001). By multivariate Cox regression model, after adjustment of procedure variables, RRPVD1 was the strongest predictor of development of severe PVS. RRPVD1 ≥25% was a strong independent predictor of development of severe PVS.     

Chrome congestive heart failure: Radiofrequency ablation of accessory pathways: implications of accumulated experience and time dedicated to procedures

Previous reports on radiofrequency ablation of accessory pathwayshave shown that the experience of the operator is of crucialimportance in reducing fluoroscopy time and achieving highersuccess rates. However, a detailed analysis of this importantissue has not been previously attempted We analysed 71 consecutive ablation procedures undertaken atSt George's Hospital by the same electrophysiology group andalways with the same first operator. Of all procedures, 66 (916%)were successful, as judged by abolition of accessory pathwayconduction without recurrence within the next 24 h. Failuresincluded two out of 38 left-sided pathway procedures (5·3%),one out of 11 intermediate septal (9·1%) and four outof 22 right-sided pathway procedures (18·2%). These differencewere not statistically significant. Average procedure and screeningtimes for all procedures were 162·9±86·0min and 56·8±48·2 mm respectively, whereasthe median of the number of discharges was 12, ranging fromone to 51. There was no significant difference between pathwaygroups or between concealed and non-concealed pathways in respectto procedure and screening time or number of discharges. Therewas a significant tendency towards decreased procedure and screeningtimes with accwnulating experience and this was similar forall pathway groups. There was also a tendency towards improvedcwnulative success rates with time dedicated to procedures. We conclude that a certain amount of ablation experience isrequired, even by experienced electrophysiologists, before arelatively high success rate without long radiation exposurecan be achieved, regardless of the location or the mode of conductionof the pathway. Success rates increase with procedure time,suggesting that early abandonment of the procedure may resultin higher failure rates in diffcult cases.     

Comparison between laser and electrical ablation of ventricle in dogs: Hemodynamic,pathologic and electrocardiographic observations

Summary To characterize and compare the pathologic, hemodynamic and electrocardiographic changes of both transeatheter laser and electrical energy on ventricle, 33 subendocardial myocardium lesions were induced at energy 60, 120 and 240 Joules by either transcatheter laser irradiation or electrical shock in 7 anesthetized dogs. The following results were observed: 1) Both laser and electrical ablation on myocardium created nonhomogeneous myocardium injury, but laser ablation caused mainly focal tissue vaporization and necrosis, while electrical shock induced widespread tissue degenerations; 2) Both laser and electrical induced-lesion dimensions increased parallel to the total dosage of energy; 3) Laser ablation caused mainly (90%) single ventricular premature beats and 86 % of them occurred within the first minute after energy discharged, while ventricular tachycardias were found in any electrical energy groups; ventricular fibrillations occurring during laser and electrical ablation were 5 % and 13 % respectively (P< 0.01): 4) A decrease in aortic blood pressure and an increase in central verous pressure induced by laser ablation were significantly less than that produced by the same amount of electrical energy (P<0.0l). Our preliminary results have shown that transeatheter laser ablation has great potential for becoming a practical method in the management of refractory tachycardias.     

顽固性室性早搏的射频消融治疗

目的 :通过对 2 3例顽固性室性早搏 (简称室早 )的射频消融分析 ,探讨室早的心电图特点、消融方法及效果 .方法 :男性 16例 ,女性 7例 ,均为频发、药物难治、症状明显的顽固性单形性室早患者 ,年龄(4 4 4± 9 6 )岁 .采用起搏标测和激动顺序标测 ,前者以起搏时与室早QRS波形态完全相同点为消融靶点 ,后者以早搏时最早心室激动点为消融靶点 .2 3例中 17例室早起源于右室 ,4例起源于左室 .消融即刻成功率86 9% ,累积放电 (930 4± 72 5 )s,成功者行动态心电图检查记录消融前后室早数为 (5 6 71± 2 4 36 )次 / 2 4h和 (39± 5 2 )次 / 2 4h (P <0 0 1) .随访 (2 3 2± 12 3)月 ,未服任何抗心律失常药 ,无 1例复发及并发症发生 .结论 :射频消融可有效而安全地消除单形性室早 ,采用粗标激动顺序、精标起搏图形 ,多点、长时间、高功率放电可提高成功率 ,降低复发率 ,可作为症状严重、药物无效或不能耐受患者的治疗选择     

阈下刺激定位慢径消融靶点的临床应用研究

目的 :探讨利用阈下刺激 (STS)定位房室结折返性心动过速 (AVNRT)的慢径消融靶点的临床应用价值。方法 :选择AVNRT患者 6例 ,经常规电生理检查明确诊断后 ,将大头电极放在冠状窦口下缘与希氏束之间的中下区域进行标测 ,测定该点的起搏阈值后 ,诱发AVNRT ,然后发放STS终止AVNRT ,在终止位点处试消融 ,观察STS标测消融的有效性 ;在非终止位点处 ,结合局部心内电图判断是否进行试消融 ,如在非终止位点处试消融 ,观察STS标测的可靠性。同时观察STS标测定位的安全性。结果 :在 6例患者中 ,有 3例STS终止了持续性AVNRT ,且在终止位点处试消融并获得成功 ;有 5例共在 10个位点处发放了STS ,其中在 9个位点未终止心动过速 ,在这些非终止位点处试消融均未获得成功 ,非 1个位点出现了心房夺获。所有患者在STS标测过程中 ,未出现心房颤动、心动过速的加速或心室颤动等现象。结论 :STS终止AVNRT的位点是判断消融靶点的一个良好的电生理学指标。STS标测定位是安全、有效和可靠的一种方法 ,值得进一步地深入研究     

Radiofrequency Catheter Ablation of an Atriofascicular Pathway During Atrial Fibrillation:

Atriofascicular Ablation During Fibrillation. Introduction: A male patient with an atriofascicular pathway underwent catheter ablation of the atriofascicular pathway during atrial fibrillation.
Methods and Results: The patient had preexcited atrial fibrillation both clinically and repeatedly during electrophysioiogic study. A preexcited tachycardia with a 1:1 AV relationship and regular RR intervals was also induced. Catheter ablation of the atriofascicular pathway could only be performed during persistent atrial fibrillation, based on mapping of the pathway's insertion into the right bundle branch. Following successful ablation and cardioversion to sinus rhythm, a regular QRS tachycardia (atrioventricular [AV] nodal reentry) having (he same rate, atrial activation sequence, and His-atrial time as the regular preexcited tachycardia noted preablation was initiated. An AV nodal slow pathway modification eliminated this tachycardia. Neither atrial fibrillation nor AV nodal reentry has recurred on follow-up.
Conclusion: This is the first report of atriofascicular mapping and ablation performed exclusively during atrial fibrillation and illustrates the utility of mapping the pathway's ventricular insertion. Other unusual features ("bystander" pathway activation during AV nodal reentry, possible role of the pathway in genesis of atrial fibrillation) are discussed.     

RADIOFREQUENCY CURRENT CATHETER ABLATION OF THE LEFT ATRIOVENTRICULAR ACCESSORY PATHWAYS WITH PAROXYSMAL SUPRAVENTRICULAR TAC

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The treatment of sulphur mustard burns with laser debridement.

The chemical warfare agent, sulphur mustard (SM), is a potent blistering agent in man. Skin exposure can produce partial-thickness burns which take up to three months to heal. The aim of this study was to investigate the use of early laser ablation as a means of accelerating this exceptionally slow rate of healing. Four circular partial-thickness SM burns were induced on the dorsum of nine large white pigs (under general anaesthesia). At 72 h post-exposure, three burns per animal were ablated with a single pass of an UltraPulse 5000C CO(2) laser, at a fluence of 5-6 J cm(-2). All the burns were dressed with silver sulphadiazine and a semi-occlusive dressing. At one, two and three weeks post-surgery three animals were culled and all lesions excised for histological analysis. Burn depth was confirmed and measurements of the radii of regenerative epithelium were performed allowing the area of the zone of re-epithelialisation in each lesion to be calculated. Laser-treated lesions showed a significant increase (350%) in healing rates compared to controls (p<0.005). At two weeks, the laser-treated sites were 95% healed in comparison with control sites (28% healed). These data suggest that laser ablation may be effective in the treatment of partial-thickness SM-induced skin injury.     

大肠癌肝转移射频消融后局部复发影响因素的分析

目的 探讨射频消融（radiofrequency ablation,RFA）治疗大肠癌肝转移后局部肿瘤复发的风险因素。方法 回顾性研究213例347个肿瘤实施RFA治疗后局部复发的临床资料,对可能影响RFA局部治疗效果的临床因素进行统计学处理。结果 175例（82.2%）298个肿瘤（85.9%）得到CT或MRI随访资料。大肠癌肝转移灶RFA后肿瘤局部复发率为36.9%（110/298）,局部复发的平均时间为16.4月（2～57个月）。单因素分析显示肝脏转移灶的部位、大小和射频针类型与肿瘤射频后的局部复发相关（P值分别为P=0.000,P=0.021和P=0.026）,但Cox多因素分析则显示只有瘤大小和转移灶部位是大肠癌肝转移射频消融后局部复发的独立预后因素（χ^2=8.522,P=0.000;χ^2=1.321,P=0.022）。结论 肝脏肿瘤的大小和部位是RFA治疗效果的独立影响因素,正确的电极选择和布针是获得肿瘤完全坏死的关键。     

支气管动脉化疗灌注联合多极射频治疗中晚期肺癌

目的评价支气管动脉化疗灌注联合多极射频治疗中晚期肺癌的临床疗效。方法对32例失去手术机会或放弃手术治疗的中晚期肺癌患者,在进行常规支气管动脉化疗灌注的同时,于首次化疗灌注后2周,在CT引导下对病灶进行多极射频治疗1次。随访并记录术后半年、1年、2年、3年的有效率与患者生存率,与单纯进行常规支气管动脉化疗灌注的38例对照组进行同期有效率与生存率的比较。结果联合治疗组术后半年、1年、2年、3年的有效率/生存率分别为:87.5%/96.9%、71.9%/81.3%、34.4%/46.9%、12.5%/21.9%。对照组有效率/生存率分别为:63.2%/78.9%、36.9%/52.6%、26.3%/36.8%、5.3%/7.9%,联合治疗组有效率与生存率均明显高于对照组,统计学有明显差异(P<0.05)。结论支气管动脉化疗灌注联合多极射频治疗中晚期肺癌,疗效明显优于单纯支气管动脉化疗灌注(P<0.05),同时可明显提高患者的生存率,是一种较为理想、安全有效的综合性治疗手段,值得推广应用。