Clinical outcomes of catheter ablation of ventricular tachycardia in patients with arrhythmogenic right ventricular cardiomyopathy: Insights from the Johns Hopkins ARVC Program

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Ventricular tachycardia in ischemic heart disease substrates

Advances in the treatment of myocardial infarction (MI) have improved survival after ischemic cardiac injury. Post-infarct structural and functional remodeling results in electrophysiologic substrates at risk for monomorphic ventricular tachycardia (MMVT). Characterization of this substrate using a variety of clinical and investigative tools has improved our understanding of MMVT circuits, and has accelerated the development of device and catheter-based therapies aimed at identification and elimination of this arrhythmia.This review will discuss the central role of the ischemic heart disease substrate in the development MMVT. Electrophysiologic characterization of the post-infarct myocardium using bipolar electrogram amplitudes to delineate scar border zones will be reviewed. Functional electrogram determinants of reentrant circuits such as isolated late potentials will be discussed. Strategies for catheter ablation of reentrant ventricular tachycardia, including structural and functional targets will also be examined, as will the role of the epicardial mapping and ablation in the management of recurrent MMVT.     

Cardiac arrhythmias: Catheter ablation of incessant ventricular tachycardia: acute and long-term results

SUBJECTS: Seventeen patients with incessant ventricular tachycardia refractoryto anti-arrhythmic therapy underwent catheter ablation between1987 and 1993. Fifteen patients had coronary heart disease andtwo had dilated cardiomyopathy. The mean age of the patientswas 65±8 and the mean left ventricular ejection fractionwas 31±9%. METHODS: Ablation sites were selected on the basis of endocardial activationmapping, concealed entrainment or bundle branch mapping. Catheterablation was performed with direct current in nine patientsand with radiofrequency energy in eight patients. Incessantventricular tachycardia was terminated by catheter ablationin all 17 patients. RESULTS: One patient died after the ablation procedure due to pericardialtamponade. During electrophysiological testing 5–14 dayslater, 7 of 16 patients (44%) had inducible sustained or non-sustainedventricular tachycardia. Five of them underwent implantationof an automatic cardioverter/ defibrillator, and three of theseexperienced discharges of the device during a mean follow-upof 30±12 months. Another patient underwent implantationof a cardioverter/ defibrillator after spontaneous recurrenceof ventricular tachycardia. Out of the nine patients withoutinducible ventricular tachycardia, one died as a result of suddencardiac death, and another had spontaneous ventricular tachycardia.Thus, ventricular tachycardia recurred clinically in 6 of 16patients (38%), in whom ventricular tachycardia with the samemorphology as that of the ablated ventricular tachycardia couldbe determined only in one patient. CONCLUSION: Catheter ablation is the method of choice for the emergencytreatment of patients with incessant ventricular tachycardia.Due to the high risk of recurrence, additional anti-arrhythmicmanagement, such as the implantation of a cardioverter/defibrillator,has to be considered.     

三维标测指导致心律失常性右心室心肌病室性心动过速的射频消融

目的介绍致心律失常性右心室心肌病（ARVC）室性心动过速（室速）的三维标测方法及其消融策略。方法21例ARVC室速患者,因1—4种抗心律失常药物治疗无效,临床上呈反复发作、无休止发作或植入型心律转复除颤器（ICD）植入后频繁放电治疗,接受导管消融治疗。其中,男性19例,女性2例,平均年龄（32±12）岁。9例患者接受电解剖（Carto）标测,12例患者接受非接触标测（EnSite—Array）。在首先明确病变基质的基础上,通过激动标测、拖带标测及起搏标测,分析心动过速的起源、可能的传导径路及其出口以及它们与病变基质的关系。通常于心动过速的出口处及其周边行局灶消融,术中病变基质周边的延迟激动电位应一并消融。结果21例患者,2例呈无休止发作,1例患者表现为频繁室性早搏及加速性室性自主心律,余18例患者消融中共诱发出34种心动过速。所有心动过速均呈左束支阻滞形,平均心动过速周长为（289±68）ms。16例患者（28种室速）消融治疗即刻成功,3例患者（7种室速）部分成功,2例患者（2种室速）消融失败,即刻消融成功率76．2％。所有患者消融术后继续服用抗心律失常药物。平均随访6～30（1d±7）个月,成功患者中2例复发,其中1例再次消融成功;未达即刻成功的5例患者,经抗心律失常药物治疗后,均无室性心律失常事件发生,其中包括1例消融后植入ICD者。结论三维标测系统可首先明确ARVC患者的病变基质,在此基础上结合激动标测和心内各种电刺激技术,可直观显示心动过速的起源、缓慢传导区出口及折返环路,以此制定消融策略可成功治疗ARVC室速。心动过速起源于心肌深部或ARVC病变进展,是消融失败和复发的常见原因。     

大剂量胺碘酮对持续性室性心动过速的纠治

目的 :观察大剂量胺碘酮治疗持续性室性心动过速 ( SVT)的临床疗效及副作用。方法 :初始以胺碘酮 15 0 m g静脉注射 (静注 ) ,5～ 10 min注射完毕 ,必要时重复 1～ 2个初始量 ,继以 0 .5～ 5 m g/ min静脉维持 3～ 8d。结果 :6例 SVT均在静脉用药 2 h内得到控制 ,2 h内静脉胺碘酮用量 3 90～ 5 4 0 ( 4 68.4± 5 4 .7) m g;2 4 h内静脉平均用量 10 0 0～ 180 0 ( 14 10 .3± 3 5 6.5 ) m g,除注射局部均发生不同程度的静脉炎外 ,未见低血压、心功能恶化及致心律失常作用。结论 :短期内经静脉大剂量应用胺碘酮安全有效     

致心律失常性右室心肌病室性心动过速的射频消融治疗

目的评价致心律失常性右室心肌病(ARVC)室性心动过速(VT)射频消融的疗效。方法 4例ARVC患者,男3例,女1例,年龄27～62岁,均有反复头昏、心悸、晕厥或黑矇病史。4例患者症状发作时共出现6种形态的VT,频率为130～210次/分。在三维标测系统(CARTO或EnSite Array)指导下行VT消融治疗。结果 4例患者共行6次手术,其中3次采用CARTO系统,3次采用EnSiteArray系统指导。3例完成消融,随访2～19个月,3例患者均无猝死、晕厥或黑矇发生;2例术后一周内复发,但VT的频率减慢,药物能有效控制,术后5～6个月VT不再发作。另1例患者在放电消融过程中VT的频率加快,形态紊乱,蜕变为心室颤动,紧急电复律后转为窦性心律,终止手术。随访6个月,无VT发生。结论致心律失常性右室心肌病VT的射频消融治疗可改善病人的症状。     

Incidence and significance of pleomorphism in patients with postmyocardial infarction ventricular tachycardia. Acute and long-term outcome of radiofrequency catheter ablation.

AIMS: The prognostic significance of multiple ventricular tachycardia (VT) morphologies, whether spontaneous or induced, was investigated in patients who underwent radiofrequency catheter ablation (RFCA) for postinfarction ventricular tachycardia. METHODS AND RESULTS: We studied 137 patients with postinfarction ventricular tachycardia. Catheter ablation of all induced ventricular tachycardias was attempted. A single ventricular tachycardia morphology was documented in 102/137 patients (MONO group); 35 patients had spontaneous pleomorphism (PLEO group). Multiple VT morphologies were induced in 58/102 (57%) MONO patients and in all PLEO patients. A higher rate of arrhythmia suppression was obtained in MONO as compared to PLEO patients (162/212 [76%] vs. 43/110 [39%]). Clinical presentation (VT pleomorphism) (OR: 0.22, CI: 0.08-0.62) and the induced VT cycle (mean PLEO/MONO: 338/385 ms, OR: 1.06) were independent predictors of acute RFCA success. Among MONO patients, the procedure was successful in 75% of the patients with a single induced ventricular tachycardia compared to 64% of those with multiple tachycardias. The acute success rate was lower in PLEO patients (23%). PLEO patients had a significantly higher 3- and 5-year arrhythmia recurrence rate than MONO patients. RFCA acute success was the only independent predictor of long-term outcome in multivariate analysis. CONCLUSIONS: Spontaneous, but not induced, VT pleomorphism in patients with prior myocardial infarction adversely affects the acute and long-term success rate of RFCA.     

Catheter ablation of ventricular tachycardia in chagasic cardiomyopathy

There is a limited experience with catheter ablation for treatment of ventricular tachycardia (VT) in Chagasic cardiomyopathy. A 30-year-old woman experienced episodes of palpitations and syncope due to attacks of VT. A diagnosis of Chagas disease was established on a biological basis. Two-dimensional echo and contrast ventriculography showed an apical aneurysm with thrombus. Surgery was indicated to resect the aneurysm and ablate the VT. Ventricular tachycardia recurred 1 month later despite therapy, including amiodarone. Two clinical frequent and well-tolerated tachycardias were identified. The site of origin was located in the right ventricular apex and in the apical-lateral wall of the left ventricle, respectively. Catheter ablation was performed at two sites with DC shocks (total energy 600 J) after unsuccessful radiofrequency ablation. Holter recordings performed during the postoperative period showed only infrequent extrasystoles. After follow-up of 24 months the patient remains asymptomatic. Drug-refractory VT in Chagasic cardiomyopathy can be ablated by medium-energy DC shocks after failure of radiofrequency ablation.