The first human experience of a contact force sensing catheter for epicardial ablation of ventricular tachycardia

Contact force (CF) is one of the major determinants for sufficient lesion formation. CF-guided procedures are associated with enhanced lesion formation and procedural success. We report our initial experience in epicardial ventricular tachycardia (VT) ablation with a force-sensing catheter using a new approach with an angioplasty balloon. Two patients with arrhythmogenic right ventricular cardiomyopathy who underwent prior unsuccessful endocardial ablation were treated with epicardial VT ablation. CF data were used to titrate force, power and ablation time.     

特发性右心室流出道室性心律失常射频消融术后复发因素分析

目的:探讨特发性右心室流出道室性心律失常射频消融术后,患者室性心律失常复发的原因,旨在为进一步降低复发率提供线索。方法:1999年12月至2009年12月,在解放军总医院老年心血管内科住院行导管射频消融的特发性右心室流出道室性心律失常患者共145例(男55例,女90例),治疗终点为室性心律失常消失,不能被心室电刺激和静滴盐酸异丙肾上腺素诱发,术后1天复查动态心电图并电话随访观察疗效。结果:在145例患者中,即刻成功136例,成功率为93.8%。随访23.8±6.7月,共有9例患者复发,复发率为6.62%。9例复发患者再次行射频消融术的靶点局部激动(34.0±7.6 ms)明显早于第一次射频消融术(30.4±8.5 ms)(P<0.05);靶点起搏与自发心律失常体表心电图QRS波形的符合数(11.8±0.45)大于第一次射频消融术(11.1±0.78)(P<0.05);复发患者第一次手术在最早激动点处单极标测r波的出现比例大于第二次手术(P<0.05),再次手术均成功。结论:导管射频消融治疗特发性右心室流出道室性心律失常是有效、可行的方法。靶点标测欠精确是术后复发的主要原因。     

Cardiomyopathy induced by incessant ventricular tachycardia originating in the vicinity of the His bundle

A 04-year-old boy was referred to our institution with severe, progressive heart failure of 4-months duration associated with a persistent wide QRS tachycardia with left bundle branch block and severe left ventricular dysfunction. Because of incessant wide QRS tachycardia refractory to antiarrhythmic drugs, he was referred for electrophysiological study. The ECG was suggestive of VT arising from the right ventricle near the His area. Electrophysiological study revealed that origin of tachycardia was septum of the right ventricle, near His bundle, however the procedure was not successful and an inadvertent complete atrioventricular conduction block occurred. The same ventricular tachycardia recurred. A second procedure was performed with a retrograd aortic approach to map the left side of the interventricular septum. The earliest endocardial site for ablation was localized in the anterobasal region of left ventricle near His bundle. In this location, one radiofrequency pulse interrupted VT and rendered it not inducible. The echocardiographic evaluation showed partial reversal of left ventricular function in the first 3 months. The diagnosis was idiopathic parahisian left ventricular tachycardia leading to a tachycardia mediated cardiomyopathy, an extremely rare clinical picture in children.     

Catheter ablation of fascicular ventricular tachycardia

Fascicular ventricular tachycardia (VT) is an idiopathic VT with right bundle branch block morphology and left-axis deviation occuring predominantly in young males. Fascicular tachycardia has been classified into three subtypes namely, left posterior fascicular VT, left anterior fascicular VT and upper septal fascicular VT. The mechanism of this tachycardia is believed to be localized reentry close to the fascicle of the left bundle branch. The reentrant circuit is composed of a verapamil sensitive zone, activated antegradely during tachycardia and the fast conduction Purkinje fibers activated retrogradely during tachycardia recorded as the pre Purkinje and the Purkinje potentials respectively. Catheter ablation is the preferred choice of therapy in patients with fascicular VT. Ablation is carried out during tachycardia, using conventional mapping techniques in majority of the patients, while three dimensional mapping and sinus rhythm ablation is reserved for patients with nonmappable tachycardia.     

Safety steps for a non-fluoroscopic approach in right-sided electrophysiology procedures: A point of view

BackgroundElectro-anatomic 3D mapping systems enable the fluoroscopy (FL) exposure to be reduced. In right-heart supraventricular tachycardia (SVT) procedures, FL could potentially be avoided. Our aim was to discuss some steps focusing on safety.Methods and resultsThe patient cohort comprised 70 consecutive SVT patients who underwent electrophysiologic (EP) catheterization. FL was routinely avoided in all cases (54.2% males, age 57.2 ± 13.3 years): 51 ablations and 19 EP study procedures. The Carto^®3 (Biosense Webster) mapping system was used in 17/70 cases (24.3%), and the EnSite Precision? (Abbott) system in the remaining 53/70 (75.7%). The mean procedure time was 94.1 ± 33.2 min; no FL was used. No major complications occurred. Acute procedural success was achieved in all 51 patients who underwent ablation. Over 3-month follow-up, arrhythmia recurred in 1 patient. There were no significant differences in procedural times between the two mapping systems, except for the time dedicated to the full geometry creation, which was longer for the EnSite Precision? system: 10 min (8.5–15 IQR) vs 8 min (5–10 IQR) for the Carto^® system (p < 0.001) mainly due to the sub-diaphragmatic navigation. The following procedural steps were considered critical in order to safely avoid FL use: “loop” advancing of catheters, the use of a fixed intracardiac reference, His signal landmark centered maps and the careful acquisition of sub-diaphragmatic extracardiac geometry.ConclusionsA routine zero X-ray approach by means of electro-anatomic 3D mapping systems is safe and effective in right-atrium procedures. Some ad-hoc discussed procedural steps may enhance safety.     

数字X线评价低温射频消融术治疗阻塞性睡眠呼吸暂停低通气综合征的临床疗效

目的:探讨颅咽部数字X线指数对阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者行低温射频消融手术治疗效果的评价作用。方法:选择2013年10月-2015年10月在我院接受低温射频消融术的OSAHS患者74例作为研究组,另选择同期在我院接受体检的健康志愿者44例作为对照组。分别于手术前后采用X线测量两组研究对象的上齿槽座角(SNA)、下齿槽座角(SNB)、上下齿槽座角(ANB)、颌上角(NA/PA);舌根后方气道前后径(PAS)、软腭后方气道横径(U-MPW)、会厌层气道前后径(V-LPW)、后鼻棘-咽顶点距(PNS-R)、舌骨最上缘至下颌骨垂直距离(H-MP)、软腭长度(SPL)、软腭厚度(SPT)以及舌骨至颈椎前平面距(H-CVP)。结果:研究组患者ANB,NA/PA,PAS,U-MPW,PNS-R及H-CVP均大于对照组,差异具有统计学意义(P0.05);两组SNA、SNB、V-LPW、H-MP、SPL及SPT比较,差异无统计学意义(P0.05);与术前相比,研究组患者术后ANB、PAS、U-MPW及H-CVP均明显改善,差异具有统计学意义(P0.05)。结论:颅咽部数字X线测量指数能够较好的评价OSAHS患者行射频消融术的治疗效果,值得临床参考。     

射频消融术治疗心动过速性心肌病的临床效果研究

目的:探讨射频消融术对心动过速性心肌病的临床治疗效果。方法:对2012年1月-2013年12月在我院就诊的34例心动过速性心肌病患者采用射频消融术进行治疗,通过心电图、X线和超声心动图检测治疗前后患者的心率(HR)、心胸比率、左心室舒张末径(LVEDD)、左心室收缩末径(LVESD)和左室射血分数(LVEF),使用SF-36生活质量调查表对治疗前后患者的生活质量进行评分。结果:所有患者经射频消融术治疗后恢复窦性心律,1例复发,复发率为3.03%,患者的呼吸困难、心悸等临床症状明显缓解。治疗后6个月,患者的HR、心胸比率、LVEDD、LVESD和LVEF均较治疗前显著改善,差异均具有统计学意义(均P0.05);治疗后1周,患者的生理机能(PF)、生理职能(RP)、躯体疼痛(BP)、一般健康(GH)、精力(VT)、社会功能(SF)、情感职能(RE)和精神健康(MH)评分均较治疗前显著升高,差异均具有统计学意义(均P0.05)。结论:采用射频消融术治疗心动过速性心肌病的临床效果好,能显著提高患者的生活质量,并改善患者的心功能。     

Catheter ablation of ventricular tachycardia originating from the left posterior papillary muscle guided by the shadow of a multipolar catheter

A 62-year-old man without structural heart disease underwent electrophysiological testing for ventricular tachycardia (VT). Hemodynamically unstable VT was induced after isoproterenol (ISP) provocation. Electroanatomical mapping using a multipolar catheter identified the earliest activation originating from the posterior papillary muscle (PPM) where prepotentials preceding the local ventricular electrogram were observed. Irrigated radiofrequency current guided by the shadow of a multipolar catheter eliminated the VT. This case suggested that multipolar catheters may be helpful for identifying tachycardia origins arising from the PPM.     

A case of ‘tachy-brady syndrome’: What is the mechanism?

A young male presented with incessant narrow QRS tachycardia and left ventricular dysfunction. 24-Holter monitoring revealed multiple episodes of sustained and nonsustained episodes of tachycardia with prolonged sinus pauses at termination. The analysis of the electrocardiogram, followed by an invasive electrophysiological study, suggested an unusual mechanism for this tachy-brady syndrome.     

Idiopathic Ventricular Tachycardia Arising From the Right Ventricular Apex

We present a rare case of idiopathic ventricular tachycardia arising from the right ventricular apex. The electrocardiographic and electrophysiological characteristics of this tachycardia are discussed.     

Feasibility of remote magnetic navigation for epicardial ablation

Percutaneous epicardial mapping and ablation is an emerging method to treat ventricular tachycardias (VT), premature ventricular complexes (PVC), and accessory pathways. The use of a remote magnetic navigation system (MNS) could enhance precision and maintain safety. This multiple case history demonstrates the feasibility and safety of the MNS-guided epicardial approach in mapping and ablation of ischaemic VT, outflow tract PVCs, and a left-sided accessory pathway. All patients had previously undergone endocardial mapping for the same arrhythmia. MNS could present an advantage from more precise navigation for mapping and maintaining catheter stability during energy application.