植入式心律转复除颤器11例临床应用观察

目的对11例经静脉安置植入式心律转复除颤器(ICD)的恶性室性心律失常患者进行临床观察，了解ICD的治疗效果。方法11例患者男性10例，女性1例，年龄(42～69)岁。基础心脏病为冠心病5例、心肌病2例、Brugada综合征1例、先天性长QT综合征1例，基础心脏病不明2例。所有患者均经临床证实有室性心动过速或／和心室颤动。ICD具有多项治疗及信息储存记忆功能，随访时通过体外程控仪调出ICD储存的资料进行分析。结果：所有患者均植入成功，随访29．3(2～64)个月，7例患者分别接受了抗心动过速起搏、电转复及电除颤治疗。1例发生1次室性心动过速，ICD未能察觉，经调整参数后，2次成功地采用抗心动过速起搏超速抑制了室性心动过速；1例患者术后4个月不明原因死亡。结论ICD是治疗恶性心律失常的有效治疗手段，常规进行随访和设定合适的诊断和治疗参数，对保证：ICD及时有效的治疗较为重要。     

双腔埋藏式心脏复律除颤器

双腔埋藏式心脏复律除颤器 (ICD)可提供起搏及抗室性和房性心律失常的治疗。报道 11例双腔ICD应用的临床体会。男 8例、女 3例 ,年龄 6 0 .5 5± 10 .0 7岁。缺血性心脏病 9例、Brugada综合征 1例、缺血性心脏病合并肥厚型梗阻性心脏病 1例。双腔ICD安置指征有 :室上性快速心律失常伴室性快速心律失常 6例 ,室性快速性心律失常伴房室阻滞 1例、伴左室功能不全 4例 ;临床上明确记录到室性心动过速 (简称室速 )、心室颤动 (简称室颤 )和室上性快速心律失常者分别为 8,2和 5例。 8例病人术前进行电生理检查 ,诱发出持续性室速 6例、室颤 2例 ;3例行电生理检查 ,其中 2例太虚弱、1例为反复发作持续性室速。 5例安置具有心室转复除颤伴心房、心室起搏的ICD ,5例安置具有心房、心室起搏转复及除颤的ICD ,1例安置具有双心室起搏及心室转复、除颤的ICD。所有病人在置入ICD时都进行除颤阈值的测定。总共有 2 3次室颤被诱发 ,除颤阈值为 12 .0 9± 5 .2 4J,除颤电极阻抗为 44 .0 0±11.0 5Ω ,P波和R波电压幅度分别为 3.5 3± 1.32mV ,13.42± 4.73mV ,心房、心室起搏阈值分别为 1.39± 0 .71和 0 .91± 0 .38V。随访 8.82± 5 .0 0 (2～ 19)个月 ,5例共有 12 0次持续性室速发生 ,其中 118次经抗心动过速起搏成功?     

植入型心律转复除颤器治疗恶性室性心律失常的疗效评价

目的评价单中心40例植入型心律转复除颤器(ICD)治疗恶性室性心律失常的疗效及安全性。方法40例恶性室性心律失常包括室性心动过速(室速)或心室颤动(室颤)患者接受ICD治疗,男性35例,女性5例,平均年龄(49±15)岁,成功随访35例,应用体外程控仪获得ICD储存资料并结合临床随访资料进行分析。结果40例患者均成功植入ICD;35例患者平均随访25个月,其中26例患者共记录室速和室颤事件763阵,ICD成功除颤224阵(成功率99．1％),抗心动过速起搏1次成功终止室速375阵(成功率71．8％),低能量同步转复22阵(成功率100％);2例患者因窦性心动过速和心房颤动伴快速心室反应发生误放电4次。术后大多数患者联合应用抗心律失常药物。至随访期末,死亡4例,3例死于顽固性心力衰竭,1例死于肺栓塞。结论ICD联合应用抗心律失常药物能有效治疗恶性室性心律失常,预防心脏性猝死。     

经静脉安置埋藏式心脏复律除颤器的临床应用

对 5例恶性室性心律失常患者安置埋藏式心脏复律除颤器 (ICD)治疗。 5例均为男性 ,年龄 39～ 74岁。冠心病 (1例为前壁心肌梗死 ) 3例 ,心肌病、扩张型心肌病伴左束支阻滞及Ⅰ度房室阻滞各 1例。药物治疗效果不佳。3例冠心病及 1例心肌病患者置入单腔ICD ,扩张型心肌病置入双腔ICD。 5例均成功置入ICD。平均起搏阈值0 .5 2V ,平均R波振幅 15 .7mV。随访 6～ 36个月 ,4例患者出现快频率室性心动过速 (简称室速 ) ,经抗心动过速起搏及低能量电击转复为窦性心律 ,平均电击能量 5 .4J。 1例发生室上性心动过速导致ICD误放电治疗 ,经重新设置室速频率窗口 ,未再出现误放电。结论 :ICD能有效转复恶性室性心律失常 ,双腔ICD因增加了心房电极 ,在改善血液动力学、预防房性及室性快速心律失常、降低不适当ICD治疗等方面优于单腔ICD     

埋藏式心脏转复除颤器患者的随访

目的报道7例埋藏式心脏转复除颤器(ICD)治疗恶性室性心律失常的情况。方法对6例单腔ICD及1例双腔ICD植入者进行随访,通过ICD程控仪调出储存的资料,了解ICD对恶性心律失常的治疗情况,并对其工作情况进行分析。结果随访5～44个月,平均23.7个月,ICD共检测到持续性室性心动过速(VT)2 129次,心室颤动(VF)6次。采用抗心动过速起搏(ATP)治疗VT的成功率为91.9%,ATP未能终止的VT经低能量转复(CV)治疗95.3%转为窦性心律,少数VT经治疗后加速为VF。高能量除颤(DF)终止VF的成功率为100%。4例12次误将室上性心动过速误判断为室性事件而启动治疗,其中2次心房颤动,10次窦性心动过速,经调整VT的识别参数及联合使用抗心律失常药物后未再发生类似情况。2例随访期间出现晕厥,ICD存储的信息显示发生了VF并复律成功。2例出现焦虑症,经心理治疗改善。结论术后严密随访,及时调整工作参数,同时关注患者的心理健康并给予针对性的心理支持和治疗,对提高ICD的治疗效果至关重要。     

经静脉心律转复除颤器的临床应用

目的　评价经静脉心律转复除颤器 (ICD)对恶性室性心律失常的治疗作用。方法　 6例药物难治性反复发作的室性心动过速 (VT)及 /或心室颤动 (VF)患者接受经静脉ICD治疗 ,并随访 12±7 0月 (1～ 2 1月 )。其中冠心病 2例 ,扩张型心肌病 1例 ,原发性室颤 3例。结果　 6例成功地置入经静脉ICD ,脉冲发生器埋于左上胸皮下 5例 ,胸大肌与胸小肌之间 1例。 3例经ICD储存资料证实共发生VT45 1次 ,均被ICD有效终止。 3例患者共有 6次VT经电击复律成功。 2例分别因窦性心动过速和心房颤动而误放电 ,其中 1例因口服胺碘酮致VT频率减慢至VT探查窗口以下而未被ICD察觉 ,经程控调整有关设置后得以纠正。结论　经静脉ICD是一种植入方法简单、能有效终止恶性室性心律失常和减少心律失常性死亡的重要手段。定期随访和针对患者改变的心律失常状况的再程控 ,是防止误放电和保证ICD有效工作的重要措施     

16例置入埋藏式心脏复律除颤器的术后随访

对 16例埋置了埋藏式心脏复律除颤器 (ICD)的患者进行随访 ,以便及时调整ICD的诊断及治疗程序 ,予病人更恰当的治疗。 16例有晕厥史的恶性室性心律失常患者置入了ICD。根据电生理检查结果设定ICD的工作程序 ,随访时通过体外程控仪调出ICD储存的资料进行分析。在出院前及第一次心动过速发作后进行资料分析 ,术后每 3个月随访一次。平均随访 30个月。结果 :16例室性心动过速 (VT)发作 789次 ,其中 12 7次为非持续性VT ,均自行终止 ;6 6 1次 (99.9% )被ICD有效终止 ,其中 6 5 0次 (98% )由抗心动过速起搏 (ATP)终止 ,9(1.4 % )次由低能量 (小于 10J)转复终止 ,2次 (0 .3% )在ATP治疗过程中加速转为VF ,由高能量除颤终止 ,1次自行终止。ICD诊断的VF共 37次 ,均被成功转复。随访过程中 2例更换过ICD ,但保留原导管系统 ,1例术后死于心力衰竭 ,1例自杀。结论 :术后严密随访及时调整工作参数 ,并在随访过程中关注患者的心理健康 ,针对性的心理支持和治疗 ,对提高ICD的治疗效果至关重要。     

埋藏式心脏复律除颤器的随访

报道 12例埋藏式心脏复律除颤器 (ICD)治疗恶性室性心律失常的结果。 10例为单腔ICD ,2例为双腔ICD ,通过ICD程控仪调出ICD内储存的资料 ,了解ICD对恶性心律失常的治疗情况 ,并对其工作情况进行分析。结果 :12例随访 16 .8± 9.9个月 ,有 8例接受成功的ICD治疗 ,占全部患者的 72 .7% ;2例 5次将快速心房颤动误识别为室性心动过速 (VT) ,1例误将窦性心动过速识别为VT ,抗心动过速起搏治疗后 1例VT加快 ,ICD识别为心室颤动 ;调整VT识别参数及联合使用抗心律失常药物后进一步随访 ,未再发生类似情况。结论 :ICD能有效终止恶性室性心律失常 ,提高患者生存率 ;随访过程中要及时调整相应参数。     

植入型心律转复除颤器临床应用

目的　观察 5例恶性室性心律失常患者植入型心律转复除颤器 (ICD)植入术及临床随访情况。方法　 5例因反复发作有血流动力学障碍的室性心动过速 /心室颤动 (VT/ VF)均顺利植入 ICD(其中双腔 ICD2例 ) ,随访 6～ 2 4个月 ,观察患者临床疗效及 ICD工作情况。结果　 5例患者无 1例死亡。随访期间共出现 VT/ VF事件 30 4次 ,ICD识别并治疗的 VT/ VF事件 71次 ,VT 6 5次 ,占 91.5 % ,VF 6次 ,占 8.5 % ,抗心动过速起搏 (ATP)终止 5 5次 ,占77.5 % ,心律转复 (CV)终止 16次 ,占 2 2 .5 % ,VF经除颤 (DF)全部一次成功。结论　 ICD的治疗效果肯定 ,需加强随访 ,及时修改参数 ,同时应加强药物的辅助治疗 ,如 β-受体阻断剂 ,胺碘酮等 ,积极改善心功能。     

埋藏式心脏转复除颤器安置的临床经验

总结非开胸经锁骨下静脉穿刺安置埋藏式心脏转复除颤器 (ICD)的手术方法、除颤阈值 (DFT)测定及ICD工作参数设置等临床经验。 10例患者 ,6例有反复晕厥病史。 2例晕厥时心电图证实为心室颤动 (简称室颤 ) ,体外电除颤成功 ,另 8例心内电生理均诱发出持续性室性心动过速或室颤。其中冠心病 8例 (1例合并Brugada综合征 ) ,扩张性心肌病 1例 ,原发性室颤 1例。 5例术前口服胺碘酮治疗。结果 :全部经锁骨下静脉置入ICD ,术中所有患者成功诱发室颤 ,并一次电击成功。手术时间 92± 2 7min。DFT≤ 2 0J,电击阻抗 4 1.2± 15 .3Ω ,R波高度 16 .3± 6 .6mV ,无手术并发症。结论 :经锁骨下静脉置入ICD方法简单 ,安全可靠 ;术前口服适量胺碘酮对术中诱发室颤无影响。     

埋藏式心脏复律除颤器治疗恶性室性心律失常的随访观察

对２２例埋置了埋藏式心脏复律除颤器（ＩＣＤ）的有晕厥史的恶性室性心律失常患者进行了随访，观察ＩＣＤ的治疗效果。２２例中扩张型心肌病８例、肥厚型心肌病２例、冠心病７例、ＱＴ延长综合症１例，４例未发现器质性心脏病。所有患者均经临床证实有室性心动过速或（和）心室颤动（ＶＴ／ＶＦ）发作。ＩＣＤ具有多项治疗及信息储存记忆功能（即第三代）。随访时通过体外程控仪调出ＩＣＤ储存的资料进行分析。平均随访７．１（１～２３）个月，１１例患者（５０．０％）ＶＴ／ＶＦ发作１１８次，其中５４次为非持续性ＶＴ，均自行终止；接受ＩＣＤ治疗的６４次为ＶＴ／ＶＦ发作，４５次为ＶＴ，２２次由ＩＣＤ的抗心动过速起搏（ＡＴＰ）终止、１６次由低能量（２～１５Ｊ）转复终止、２次发作为窦性心动过速（误判为ＶＴ），其余５次ＶＴ在ＡＴＰ治疗过程中加速转为ＶＦ，由高能量除颤终止。ＩＣＤ诊断的ＶＦ发作共有１９次，发生于４例患者，有１例患者接受除颤１６次，４次系为频率超过ＶＦ感知频率的ＶＴ。１９次发作均被ＩＣＤ有效除颤终止。２例扩张型心肌病患者，１例术后３个月死于心功能衰竭，另１例术后２个月反复发作ＶＦ，多次接受ＩＣＤ除颤治疗，最后死于心功能衰竭。结果表明常规进行?     

The implantable cardioverter-defibrillator and hypertrophic cardiomyopathy. Experience at three centers

INTRODUCTION AND OBJECTIVES: Although implantable cardioverter-defibrillators (ICDs) are recommended for high-risk patients with hypertrophic cardiomyopathy (HCM), there is no agreement on their general use. Moreover, little information is available on ICD use in this setting in Spain. Our aims were to describe the characteristics of HCM patients who received ICDs at three hospitals in Spain, and to study indications for device implantation and the results of follow-up in device users. METHODS: We evaluated risk factors for sudden death in HCM patients with ICDs, including family history of sudden death, recurrent syncope, maximum wall thickness > or =30 mm, left ventricular outflow pressure gradient >30 mmHg, abnormal blood pressure response to exercise, and nonsustained ventricular tachycardia. During regular follow-up, appropriate and inappropriate administration of ICD therapy was recorded. RESULTS: Of 726 HCM patients, 45 (6.2%) had an ICD (mean age 43 [20] years). The proportion of patients with ICDs at the three centers studied was highly variable despite patients' clinical characteristics being similar. The indication for implantation was primary prevention in 27 patients and secondary prevention in 18. During follow-up (median 32 months), ICD therapy was administered appropriately in 10 (22.0%) patients (in nine, as secondary prevention and, in one, as primary prevention). The annual appropriate ICD therapy rate was 11.1% for secondary prevention and 1.6% for primary prevention. Two patients received an ICD to treat ventricular fibrillation and eight, to treat sustained ventricular tachycardia. The only significant predictor of appropriate ICD therapy was a history of sustained ventricular tachycardia or ventricular fibrillation (hazard ratio =13.3, P=.014). CONCLUSIONS: The percentage of HCM patients undergoing ICD implantation at Spanish hospitals was highly variable, possibly due to different selection criteria. When used as secondary prevention, ICD therapy was administered appropriately in a high proportion of cases (50% in 3 years).     

Implantable cardioverter defibrillator (ICD) in children

BACKGROUND: Implantable cardioverter defibrillators (ICD) proved to be effective in the prevention of sudden cardiac death in adults. In children, the experience of ICD therapy is limited. This retrospective study was undertaken to review our experience with ICD implantation in children with special consideration of psychosocial impact of this therapy. METHODS AND RESULTS: Sixteen children (f:5, m:11, median age 12.2 years, range 4-15.9 years) received an ICD. Eleven patients had survived sudden cardiac death with documented ventricular fibrillation (VF) and five patients had sustained ventricular tachycardia (VT) with hemodynamic significance. The underlying heart disease was congenital in 5, hypertrophic cardiomyopathy in 2, myocarditis in 2 and primary electrical in 7 patients. All leads were implanted transvenously. Mean follow up was 43.1 months (range 1-105 months). All patients are alive. In 7 patients, a total of 387 sustained VT episodes were detected by the ICD. At follow-up, 10 inappropriate shocks were delivered in four patients. One early and six late lead revisions were done in seven patients. 12/16 (75%) patients had concomitant antiarrhythmic drug therapy. About half of the adolescents showed signs of depression and/or anxiety. CONCLUSION: ICD therapy via transvenous access for prevention of sudden cardiac death is feasible and effective even in small children. However, the occurrence of lead complications is significant. Since about half of the adolescents showed signs of depression and/or anxiety, professional psychological surveillance should be considered in these patients.     

Predictors of appropriate implantable cardioverter-defibrillator therapy in patients with idiopathic dilated cardiomyopathy

Evaluating predictors of appropriate implantable cardioverter-defibrillator (ICD) therapy in patients with idiopathic dilated cardiomyopathy (IDC) may be helpful in developing risk stratification strategies for these patients. Fifty-four patients with IDC underwent ICD implantation and were followed up. Twenty-three patients (42%) had a class I indication for ICD implantation; the remaining patients underwent implantation for multiple risk factors for sudden death including left ventricular dysfunction, nonsustained ventricular tachycardia, syncope, or positive electrophysiologic study results. Clinical, electrocardiographic, and electrophysiologic data were collected. Appropriate ICD therapy was defined as an antitachycardia pacing therapy or shock for tachyarrhythmia determined to be either ventricular tachycardia or ventricular fibrillation. Appropriate ICD therapy was observed in 23 patients (42%). There was a significant difference in use of beta-blocker therapy between patients who did and did not have appropriate ICD therapy (p <0.0003). Cox regression analysis identified the following univariate predictors (p <0.1): class I indication (p <0.005) and lack of use of beta-blocker therapy (p <0.0007). In multivariate analysis, only lack of beta-blocker use (relative risk 0.15, 95% confidence intervals 0.05 to 0.45; p <0.0007) was identified as a predictor of appropriate ICD therapy. Of the patients who received ICD therapy, only 4 (17%) were taking beta blockers, whereas 21 of the 31 patients (68%) who did not receive ICD therapy were treated with beta blockers (p <0.0003). In patients with IDC selected for ICD implantation, the most consistent predictor of appropriate ICD therapy was lack of beta-blocker use. Attempts should be made to administer beta blockers to these patients, if tolerated.     

Experience of cardioverter-defibrillators inserted without thoracotomy: evaluation of transvenously inserted intracardiac leads alone or with a subcutaneous axillary patch.

OBJECTIVES--To compare the efficacy of a purely transvenous cardioverter-defibrillator (ICD) system with that of a system with a supplementary subcutaneous patch. To evaluate clinical follow up of these lead arrangements that do not require thoracotomy. DESIGN--A simplified defibrillation protocol to test two different lead arrangements during implantation, with routine clinical follow up after implantation. SETTING--Tertiary referral centre for treatment of arrhythmia. PATIENTS--22 consecutive patients selected for implantation of an ICD because of life-threatening ventricular arrhythmias (ventricular fibrillation or sustained ventricular tachycardia) of whom 20 entered the test protocol. INTERVENTION--Implantation of an ICD with transvenously inserted intracardiac leads and a subcutaneous patch and assessment of effective defibrillation followed by testing of the purely transvenous approach. MAIN OUTCOME MEASURES--Reproducible conversion of ventricular fibrillation to sinus rhythm at a certain energy level, providing a safety margin of at least 10 J for both lead arrangements. Confirmation of efficacy during clinical follow up (mean 6 months). RESULTS--A transvenous lead system combined with a subcutaneous axillary patch was implanted in 20/22 patients and it provided adequate and acceptable energy levels. In 10/20 tested patients a purely transvenous lead configuration provided an acceptable safety margin as well. Nine patients had clinical recurrences: all these arrhythmias were successfully converted. CONCLUSION--A transvenous lead system was sufficient in 50% of the patients at the time of implantation. Data on long-term clinical follow up of this arrangement are not available. The approach without thoracotomy with a subcutaneous patch is feasible and effective in most patients selected for ICD treatment.     

Implantable cardioverter-defibrillators in children

BACKGROUND: Implantable cardioverter-defibrillators (ICD) have been increasingly used in adult patients for the prevention of sudden cardiac death (SCD). The usefulness and feasibility of ICD implantation in children have been less well established. AIM: To analyse indications, results and safety of ICD therapy in children. METHODS: ICDs were implanted in seven children, aged from 6 to 17 years. All patients underwent cardiological evaluation which included analysis of medical history, physical examination, chest X-ray, standard ECG, 24-hour Holter ECG monitoring and echocardiography. RESULTS: In five children devices were implanted due to aborted sudden death (ventricular fibrillation) whereas in the remaining two - as a primary prevention of SCD. Three children had hypertrophic cardiomyopathy, one - dilated cardiomyopathy, one - mitral valve prolapse and QT prolongation, one - congenital long QT syndrome and the remaining patient - idiopathic ventricular tachycardia. Single-chamber devices were implanted in six children, and dual-chamber system - in one patient. In all patients endocardial leads were implanted and ICD pocket was formed under the greater pectoral muscle. During follow-up ranging between four months to 5.4 years, four children developed ventricular fibrillation or ventricular tachycardia which were terminated by appropriate ICD discharges. CONCLUSIONS: 1. ICD implantation in children is effective in the prevention of SCD. 2. In our population, the most frequent indications for device implantation were life-threatening ventricular arrhythmias occurring in patients with cardiomyopathy. 3. Cardiac arrest due to ventricular fibrillation may occur in children without a history of aborted SCD. 4. ICD implantation in children is feasible and safe.     

ICD在恶性室性心律失常治疗中的应用

目的观察埋藏式心脏复律除颤器(ICD)在治疗恶性室性心律失常中的作用。方法对2005年1月至2009年11月在我院植入ICD的96例患者的临床资料及植入ICD后的长期随访结果进行回顾性分析,其中男80例,女16例,年龄14~79岁(53±12.2岁)。结果①植入ICD进行一级预防的患者32例(33.33%),二级预防64例(66.67%);②病因分析显示致心律失常性右室心肌病11例(11.46%),肥厚型心肌病8例(8.33%),缺血性心肌病29例(30.21%),扩张型心肌病13例(13.54%),长QT综合征1例(1.04%),Brugada综合征10例(10.42%),多形性室速19例(19.79%),特发性室颤4例(4.17%),心肌致密化不全1例(1.04%);③临床表现为持续性室速或室颤64例(66.67%),其中合并有房速16例(16.67%);④起搏模式为:单腔ICD54例(56.25%),双腔ICD42例(43.75%);⑤术中测试ICD的起搏参数并诱发心室颤动,采用20J一次电击复律成功;⑥随访结果显示植入ICD后共发生室性心律失常事件426阵次,共启动抗心动过速起搏(ATP)治疗378阵次,成功304次(成功率80.42%);高能量放电90次;有3次为窦性心动过速或房颤伴快速心室率所致的不恰当治疗。结论 ICD能有效治疗恶性室性心律失常,预防心脏性猝死;ATP是ICD治疗的有效方法;术后定期随访,及时优化ICD参数,合理选用辅助治疗,可减少不恰当治疗及提高ICD治疗的成功率。     

Long-term follow-up in patients with arrhythmogenic right ventricular cardiomyopathy

Long‐Term Prognosis in Patients with ARVC. Introduction: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a major cause of sudden cardiac death due to tachyarrhythmias. The purpose of this study was to investigate the long‐term prognosis in patients with ARVC and the incidence of rapid ventricular arrhythmias during follow‐up. Methods: Thirty ARVC patients (19 male, 63.3%, mean age 48 ± 15 years) fulfilling modified Task Force criteria 2010 were included. Of them, 13 patients (43.3%) received implantable cardioverter‐defibrillator (ICD) implantation. Rapid ventricular arrhythmia was defined as electrical storm or the occurrence of ventricular tachycardia (VT) or ventricular fibrillation (VF) with a cycle length of 240 ms or less that necessitate shock delivery to 2 or more times within a 24‐hour period. Results: With a mean follow‐up of 68 ± 10 months, 6 patients (20%) with ICD implantation had recurrent rapid VT/VF. One (3.3%) of them died of multiple shocks and SCD, and 5 (16.7%) had multiple ICD therapies due to VT/VF and electrical storm. The interval between the diagnosis of ARVC and occurrence of rapid VT/VF was 13.4 ± 4.9 months. Most (5/6, 83.3%) events of recurrent rapid VT/VF occurred within 2 years. Ablated patients who did not receive an ICD implant were totally free of rapid VT/VF. Conclusions: For patients with ARVC, long‐term prognosis is favorable. During a long‐term follow‐up, patients meeting the criteria for ICD implantation have a higher rate of rapid and potentially life‐threatening arrhythmias. However, early and clustered recurrence of rapid VT/VF in patients with an ICD is common, whereas late occurrence of rapid VT/VF is very rare. (J Cardiovasc Electrophysiol, Vol. 23, pp. 750‐756, July 2012)