Management of electrical storm of unstable ventricular tachycardia in post myocardial infarction patients: A single centre experience

ObjectiveThis is a case series of consecutive patients with past myocardial infarction presenting with Electrical Storm (ES) of unstable ventricular tachycardia (VT) treated by a protocol directed algorithm.MethodsManagement protocol involved treatment of reversible causes, ventilatory & hemodynamic support, administration of antiarrhythmic drugs (AAD) & maximally tolerated doses of beta-blockers, stellate ganglionectomy and Radiofrequency ablation (RFA) guided by Electro Anatomic Mapping (EAM). Patients were followed up periodically with review of device data logs.ResultsThere were 12 patients (mean age = 61.38 ± 6.48 years & mean LVEF = 31.92 ± 4.23%). Presentation was recurrent ICD shocks (n = 5) or VT (n = 7). All were mechanically ventilated. Reversible causes were identified in 4 patients and appropriately addressed. Totally 8 patients underwent endocardial substrate modification by EAM & RFA. Endocardial LV Voltage mapping demonstrated a mean scar area of 70.04 ± 17.63 sq.cm (27.04 ± 6.20% of mapped area). The electrograms targeted for ablation included late potentials, fractionated electrograms, double potentials and channels within the scar. Two patients had stellate ganglionectomy in addition. Ten patients (83.3%) survived to discharge, all of whom are alive at a follow up of 30.12 ± 19 months free of ES. VT free survival at end of follow up was 80%. No patient had hospitalization related to VT. Single episode of VT recurrence was seen in 2 patients at 7 months and 1 year of follow up respectively.ConclusionIn post myocardial infarction patients presenting with ES and unstable VT, a protocol driven approach involving substrate modification targeting abnormal electrograms improves outcomes.     

His-Purkinje system re-entry in patients with clustering ventricular tachycardia episodes

Aims: Multiple arrhythmia re-inductions were recently shown in His-Purkinjesystem (HPS) ventricular tachycardia (VT). We hypothesized thatHPS VT was a frequent mechanism of repetitive or incessant VTand assessed diagnostic criteria to select patients likely tohave HPS VT. Methods and results: Consecutive patients with clustering VT episodes (>3 sustainedmonomorphic VT within 2 weeks) were included in the analysis.HPS VT was considered plausible in patients with (i) impairedleft ventricular function associated with dilated cardiomyopathyor valvular heart disease; or (ii) ECG during VT similar tosinus rhythm QRS or to bundle-branch block QRS. HPS VT was plausiblein 12 of 48 patients and HPS VT was demonstrated in 6 of 12patients (50%, or 13% of the whole study group). Median VT cyclelength was 318 ms (250–550). Catheter ablation was successfulin all six patients. Conclusion: His-Purkinje system VT is found in a significant number of patientswith repetitive or incessant VT episodes, and in a large proportionof patients with predefined clinical or electrocardiographiccharacteristics. Since it is easily amenable to catheter ablation,our data support the screening of all patients with repetitiveVT in this regard and an invasive approach in a selected groupof patients.     

Successful catheter ablation of a ventricular tachycardia storm originating from the left ventricular posterior papillary muscle involved with a remote myocardial infarction

A 61-year-old man with a remote posterior myocardial infarction underwent electrophysiological testing for a ventricular tachycardia (VT) storm. Repeated cardioversions terminated the VT with immediate resumption after one sinus beat. Pacing neither terminated the VT nor demonstrated transient entrainment. Echocardiographically guided electroanatomic mapping revealed a centrifugal activation from the septal mid-apical region of the left ventricle on the septal portion of the posterior papillary muscle where a high frequency potential was observed within the local ventricular electrogram. Irrigated radiofrequency current at this site eliminated the VT. This case suggested that papillary muscles may be a target for catheter ablation of electrical storms after myocardial infarctions.     

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.     

经导管射频消融心律转复除颤器植入后电风暴

目的报道3例心律转复除颤器（ICD）植入后抗心律失常药物治疗无效的室性心律失常电风暴患者经导管射频消融的结果。方法2名男性与1名女性患者,年龄为75、55、37岁,分别患有陈旧性前壁心肌梗死、致心律失常性右心室心肌病、左心室心肌病。均在ICD植入后发生抗心律失常药物治疗无效的电风暴。应用Carto电解剖标测系统引导盐水灌注射频导管标测和消融室性心动过速（VT）。对可标测VT（持续性、血流动力学稳定）行激动和拖带标测;对不可标测VT,则在基质标测的基础上行起搏标测和／或短时间的拖带标测。结果3例患者中共诱发出5种形态的VT,4种血流动力学较稳定VT和1种血流动力学不稳定VT。成功消融了所有形态的VT,抑制了电风暴的急性发作。消融后随访的6、19和36个月中,仅1例患者出现1次ICD放电。结论在电解剖标测的基础上,应用盐水灌注射频导管消融ICD植入后抗心律失常药物治疗无效的电风暴有很好的疗效。     

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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室性心动过速的基质标测与消融

目的 探讨使用Carto三维系统标测致心律失常性右心室心肌病(ARVD/C)室性心律失常的基质来指导导管消融的安全性和有效性.方法 自2007年7月至2008年4月,北京大学第一医院心内科连续收治4例ARVD/C患者,年龄28～53岁,男性3例,女性1例,其中1例患者有直系亲属猝死家族史,发作性室性早搏/室性心动过速(VT)病史3个月至24年.使用Carto三维系统进行电解剖电压标测,局部电压低于1.5 mV的区域判断为病变心肌,低于0.5 mV的区域为瘢痕区,结合传统的激动顺序标测、起搏标测、拖带标测和心室内碎裂电位,识别病变心肌范围和心动过速折返路径以指导消融.结果 4例患者电生理检查共诱发出7种形态的左束支阻滞形、VT,电解剖电压标测的低电压区主要位于右心室流人道的基底部和偏间隔部,在病变心肌与正常心肌交界区和/或环绕病变心肌的最早激动处做线性消融,4例患者均获消融即刻成功,无并发症.4例患者消融术后随访3个月至1年,有1例出现复发,口服胺碘酮控制,至今无晕厥和猝死.结论 ARVD/C的VT标测与消融安全可靠,应用三维系统进行电解剖电压标测与传统的心电标测方式相结合,可更精确判断ARVD/C的室性心律失常基质和有效提高消融成功率.