Catheter ablation of ventricular tachycardia in arrhythmogenic right ventricular dysplasia

Arrhythmogenic right ventricular dysplasia (ARVD) is a progressive, genetically determined fibro-fatty infiltrative myocardial disease with an estimated prevalence in the general population to be 1:5,000 to 1:10,000. ARVD leads to electrical instability that may predispose to life-threatening ventricular arrhythmia, heart failure, and sudden death. We reviewed the pathological substrate for ventricular arrhythmias, ECG findings and treatment modalities in ARVD. Importantly, novel techniques such as electroanatomic and voltage mapping has greatly improved the identification of the scared substrate in the settings of ARVD and have improved safety and efficacy of VT ablation procedures associated with this entity.     

A case of arrhythmogenic right ventricular dysplasia with ventricular fibrillation

A case of repeated attacks of ventricular fibrillation is described. The patient suffered from an arrhythmogenic right ventricular dysplasia (ARVD) documented by right and left ventriculograms and myocardial biopsies obtained during surgical treatment of the arrhythmia. The histological changes were interpreted as being signs of fresh myocardial damage of unknown origin in addition to a replacement of the normal myocardium by adipose and fibrotic tissue. The repeated attacks of ventricular fibrillation in this patient contrast to the arrhythmia spectrum noted in the available literature on ARVD, mostly stable chronic ventricular tachycardias.     

Electrocardiographic recognition of right ventricular hypertrophy

The electrocardiogram (ECG) is a relatively insensitive tool for the detection of right ventricular hypertrophy (RVH), but some criteria have high specificity. The recommended ECG screening criteria for RVH are not sufficiently sensitive or specific for screening for mild RVH in adults without clinical cardiovascular disease. The greatest accuracy of the ECG is in congenital heart disease, with intermediate accuracy in acquired heart disease and primary pulmonary hypertension in adults.     

致心律失常性右室心肌病（ARVC）临床和病理观察（附3例报告）

目的 通过所遇的病例,学习有关献,提高对ARVC的认识,特别是对中青年的不明原因心律失常,早期识别、预防猝死。讨论 病因,目前普遍认为是常染色体遗传病,可为显性、不完全外显及隐性。也提出心肌被脂肪组织所替代是慢性心肌炎引起的后天性损伤（炎症、坏死）和修复过程演进的结果。诊断 主要依据心慌、头晕、昏厥等症状,结合心电图有典型的室性早搏、短车室速、室颤,QRS时限≥110ms,进一步可对其心脏形态及功能进行评价。组织学检查为诊断ARVC的金标准,但心内膜活检须注意取材部位,预防室壁穿孔等并发症。治疗 目前主张一般情况用药物抗心律失常,严重可植入除颤器,也可经外科手术治疗或心脏移植。     

Noninvasive risk stratification in arrhythmogenic right ventricular cardiomyopathy

The natural history of arrhythmogenic right ventricular cardiomyopathy is determined by the electrical instability of the dystrophic myocardium, which can precipitate arrhythmic cardiac arrest any time during the course of the disease and by the progressive myocardial loss that results in ventricular dysfunction and heart failure. Sudden death accounts for the majority of the fatal events but its occurrence is mostly unpredictable. There are no prospective and controlled studies assessing clinical markers that can predict the occurrence of life-threatening ventricular arrhythmias. However, the noninvasive risk profile, which emerges from retrospective analysis of clinical and pathologic series, is characterized by history of syncope, physical exercise, spontaneous ventricular tachycardia or ventricular fibrillation, right ventricular dysfunction, left ventricular involvement, right precordial negative T wave, right bundle branch block, QT-QRS dispersion, right precordial ST-segment elevation and late potentials. At present only QRS dispersion, history of syncope and right and/or left ventricular abnormalities at radionuclide angiography proved to be independent noninvasive predictors of sudden death.     

致心律失常性右室心肌病高危患者相关危险因素分析

目的探讨致心律失常性右室心肌病(ARVD/C)高危患者相关危险因素。方法根据1994年ARVD/C诊断标准,纳入43例ARVD/C先证者。分组标准:有晕厥病史并记录到室性心动过速(简称室速)为高危病人;记录到室性早搏(简称室早)、室速但无晕厥病史及其他临床情况定为低危病人。收集参数包括:①心电图V1～3QRS波时限≥110 ms、V1～3导联S波升支时限≥55 ms、Epsilon波、T波倒置、(V1+V2+V3)/(V4+V5+V6)QRS波时限≥1.2、QRS波离散度≥40 ms、QT离散度≥65 ms;②信号平均心电图记录晚电位参数;③Holter记录室早或室速;④超声记录双房、双室及右室流出道、流入道内径大小。Logistic回归分析高危患者ARVD/C病人的相关危险因素。结果心室晚电位阳性、右室射血分数<0.40与高危ARVD/C显著相关。结论晚电位阳性、右心功能不全是ARVD/C的高危因素。     

Bundle branch reentry ventricular tachycardia in arrhythmogenic right ventricular dysplasia

A 42-year-old male had history of recurrent palpitation and was documented to have wide QRS tachycardia. Magnetic resonance imaging angiogram showed evidence of arrhythmogenic right ventricular dysplasia and severe right ventricular dysfunction. Electrophysiology study showed evidence of bundle branch reentry ventricular tachycardia. It was successfully treated by radiofrequency ablation of right bundle branch. This is probably the first case of bundle branch reentry as a mechanism for ventricular tachycardia in a case of arrhythmogenic right ventricular dysplasia.     

致心律失常性右心室发育不良的心电表现

5例致心律失常性右室发育不良,共同的心电特征是:1.反复发作LBBB型室速;2.右胸导联QRS波示右室肥大或呈RBBB,或形态介于两者之间(3例有J波);3.Tv_1-3倒置;4.心室晚电位阳性;5.电生理检查可诱发LBBB型室速。这些特点可为本病的诊断提供线索。     

Activation delay and VT parameters in arrhythmogenic right ventricular dysplasia/cardiomyopathy: toward improvement of diagnostic ECG criteria

Introduction: Desmosomal changes, electrical uncoupling, and surviving myocardial bundles embedded in fibrofatty tissue are hallmarks of activation delay in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). Currently, generally accepted task force criteria (TFC) are used for clinical diagnosis. We propose additional criteria based on activation delay and ventricular tachycardia (VT) to improve identification of affected individuals.
Methods and Results: Activation delay and VT-related 12-lead electrocardiographic (ECG) criteria were studied, while off drugs, in 42 patients with proven ARVD/C according to TFC, and 27 controls with idiopathic VT from the RV outflow tract. Two of three measured TFC could only be identified in a small minority of ARVD/C patients. Additional ECG criteria proposed in this study included (a) prolonged terminal activation duration, an indicator of activation delay; (b) VT with LBBB morphology and superior axis; and (c) multiple different VT morphologies. These criteria were met in 30 (71%), 28 (67%), and 37 (88%) ARVD/C patients, respectively, and in one control patient (P < 0.001). Electrophysiologic studies contributed importantly to yield different VT morphologies. Pathogenic plakophilin-2 mutations were identified in 25 (60%) of ARVD/C patients and in none of the controls. In ARVD/C patients, parameters measured were not significantly different between mutation carriers and noncarriers, except for negative T waves in V1–3, occurring more frequently in patients with mutation.
Conclusions: The proposed additional criteria are specific for ARVD/C and more sensitive than the current TFC. Therefore, adding the newly proposed criteria to current TFC could improve ARVD/C diagnosis, independent of DNA analysis.     

Newly diagnosed arrhythmogenic right ventricular dysplasia in an octogenarian

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is thought to be a disease of the young, with the majority of newly diagnosed patients under 40 years of age. Establishing this diagnosis in elderly patients may be challenging, and a few reports exist of patients older than 70 years diagnosed with ARVD/C at autopsy. We report the case of an octogenarian with antemortem newly diagnosed ARVD/C. This case report represents the oldest patient to date to have a newly established diagnosis of ARVD/C and highlights the difficulty in making the diagnosis in the elderly.     

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)     

致心律失常性右室心肌病七个家系调查

目的调查致心律失常性右室心肌病(ARVC)家系,提供国人ARVC的遗传学资料及家系成员的患病情况.方法调查就诊16例ARVC患者的家族史,包括询问家系成员病史,做心脏检查.根据欧洲心脏病协会的诊断标准作出诊断.结果16例患者中7例有家族史(44%),该7个家系中查出ARVC患者31例,平均年龄(38.9±15.0)岁.所有家系均表现为显性遗传.除先证者外,家系患者有症状者占19%.每个家系各有发病特点.右胸导联QRS波后部切迹在家系患者中多见.家系患者心室晚电位阳性者占74%.超声心动图显示3个家系的所有22例患者都有右室肌小梁增粗.右室的变化多集中于发育不全三角.病变部位室壁变薄伴有室壁瘤样收缩期膨出及运动障碍相当多见.病变严重者,右房、右室普遍扩大.结论国人ARVC多为显性遗传,有遗传异质性,临床表现复杂,多见于青壮年.     

动态基质标测在致心律失常右室心肌病患者室性心动过速射频消融中的应用

目的　探讨应用非接触球囊导管标测系统行动态基质标测,指导对致心律失常右室心肌病(ARVC)患者室性心动过速(室速)消融的价值。方法　应用非接触球囊导管标测系统在窦律下对 3例ARVC室速患者行动态基质标测,在确定室速的最早激动点、出口部位和传导顺序后,寻找与室速相关的峡部并行线性消融。结果　3例患者存在 3种不同形态的基质,分别位于右室流出道、右室前壁和右室前侧壁。共诱发 5种室速,平均心动周期为(348±65)ms,其中 3种室速起源于基质或基质边缘, 2种室速的起源远离基质; 1种室速经基质传导。5种室速全部消融成功。平均随访 20个月,无心动过速发作。结论　应用非接触球囊导管标测系统确定异常电生理基质有助于理解ARVC室速的发生机制和制定消融策略,行室速相关峡部的线性消融可有效治疗室速。     

Quantitative analysis of the signal-averaged QRS in patients with arrhythmogenic right ventricular dysplasia

Temporal signal averaging of the surface QRS (VI + V3 + V5)was performed in 16 patients with arrhythmogenic right ventriculardysplasia and in 16 normal subjects. The differences betweenARVD patients and normals were large for the filtered QRS duration(FQRSd) (146.2±18.9 vs. 91.8±4.1ms, P<000001),the late potential duration (LPd) (83.5±23.3 ms vs. 23.6±4.6ms,P< 0.00001), the LPd/ FQRSd ratio (53.9± 10.1% vs.25.8±5.1%, P <0.00001), the filtered QRS amplitude(234.0±61.1µV vs. 429±942 fiV, P <0001),and the root mean square voltage of the signals in the terminal40 and 50 ms of the FQRS (RMS40 and RMS50) (18.4± 10.0µVvs. 118.4±49.8p.V, P<0.0005 and 27.9± 19.2µVvs. 217.0±66.3fiV, P<0000002). RMS50 <40µVdiscriminated best between ARVD and normals (81% sensitivityand 100% specificity). The right-sided predominance of the abnormalitiesin ARVD was demonstrated by the significantly longer FQRSd andLPd, and the higher ratio LPd/FQRSd in right than in left precordialleads. The arrhythmia susceptibility did not seem to influencethe presence of or properties ofLP in the ARVD group. Patientswith multiple QRS morphologies during ventricular tachycardia(VT) had, compared with patients with only one type of VT, longerLPd (108.3 ±46.4 ms vs. 64.2 ±31.7 ms, P<0.02)and lower RMS40 voltage (9.4±9.9 µV vs. 25.4±21.6µV, P<0.05). The relative heart volume was positivelycorrelated with delayed activity, but an enlarged heart wasnot apre-requisitefor the presence ofLP. The method thus identifieschanges which are specific to ARVD. The findings indicate thatcertain electrical or morphological conditions are requiredfor the occurrence of arrhythmias.     

心电图评价致心律失常性右心室心肌病病变程度的临床价值

目的 分析致心律失常性右心室心肌病(ARVC)患者的病变程度与心电图表现之间的关系.方法 分析61例已确诊的ARVC患者,根据心脏核磁共振成像(MRI)检查结果,将其按病变侵犯部位分为右心室局部病变组、右心室弥漫病变组、双心室病变组,分析比较三组的心电图特征.结果 心脏MRI结果显示右心室局部病变组19例(31%),右心室弥漫病变组28例(46%),双心室病变组14例(23%).心电图正常者3例,三组中各1例.伴有Epsilon波的患者24例(39%)、V1～V3导联的QRS波时限≥110 ms的患者21例(34%)、V1～V3导联S波升支≥55 ms的患者17例(28%)、完全右束支传导阻滞的患者10例(16%)、病理性Q波的患者9例(15%),这些指标的发生率均随病变程度的加重而增高(右心室局部病变组＜右心室弥漫病变组＜双心室病变组).Epsilon波、V1～V3导联的QRS波时限≥110 ms、完全性右束支传导阻滞(RBBB)、病理性Q波的发生率在双心室病变组中要高于右心室局部病变组,且两组间比较差异有统计学意义(P＜0.05).V1～V3导联S波升支≥55 ms的发生率在双心室病变组中要高于右心室局部病变组,且两组间比较差异有统计学意义(P＜0.05);在双心室病变组要高于右心室弥漫病变组,且两组间比较差异均有统计学意义(P均＜0.05).一度房室传导阻滞的发生率在双心室病变组中要高于右心室弥漫病变组,且两组间比较差异有统计学意义(P＜0.05).右心室局部病变组患者心电图T波倒置多局限于V1导联,右心室弥漫病变组和双心室病变组T波倒置多数表现于胸前导联V1～V3或超过V3导联的胸前导联、以及下壁导联.结论 心电图正常并不能排除ARVC.ARVC患者T波倒置在12导联心电图上具有很高的发生率,并且T波倒置在胸部导联的延伸与病变程度是相关的,T波倒置的范围可以提示ARVC病变累及的程度.

Abstract：

Objective To analyze the relationship between electrocardiographic (ECG) features and disease severity in patients with the arrhythmogenic right ventricular cardiomyopathy (ARVC). Method The study group consisted of 61 subjects with a definite diagnosis of ARVC on the basis of published guideline criteria and patients were divided into 3 subgroups according to the extent of diseased myocardium defined by cardiac magnetic resonance imaging (MRI): Group A: local involvement (n = 19, 31% ), Group B: diffuse involvement of whole right ventricle ( n = 28, 46% ) and Group C: involvement of both right and left ventricles ( n = 14, 23% ). Results Normal electrocardiogram was shown in 1 patient in each group.Epsilon wave was detected in 24 (39%) patients, QRS duration was prolonged [≥ 110 ms( V1 -V3 )] in 21 (34%) patients, S-wave upstroke was prolonged (≥55 ms) in 17 (28%) patients, complete right branch bundle block was evidenced in 10 ( 16% ) patients and pathologic Q waves was found in 9 ( 15% ) patients. The incidence of above abnormal ECG changes was increased in proportion to the degree of disease severity (group A ＜ group B ＜ group C). Incidence of Epsilon wave and prolonged QRS duration [≥ 110 ms (V1 - V3 )] were significantly higher in Group C than in Group A. Incidence of prolonged S-wave upstroke ( ≥55 ms) was significantly higher in Group C than in Group A and Group B. T-wave inversion in V1 leads was often found in Group A. T-wave inversion in inferior leads ( V1 - V3 leads or beyond V3 ) was often presented in Group B and Group C. Conclusions Normal ECG does not exclude the possibility of diagnosis of ARVC. The extent of T-wave inversion in the precordial leads and incidence of Epsilon wave, prolonged QRS duration [≥ 110 ms (Vt -V3 )] and prolonged S-wave upstroke ( ≥55 ms) were related to degree of disease severity in patients with ARVC.     

致心律失常性右室心肌病患者Epsilon波的检出率

目的 探讨不同体表心电图记录方法对国人致心律失常性有室心肌病(arrhythmogenic right ventricular eardiomyopathy,ARVC)患者Epsilon波检出率的影响.方法 共人选ARVC患者32例,男性24例,女性8例,年龄18～70(42.3±13.3)岁.于安静仰卧位记录窦性心律情况下的标准12导联同步心电图(standard twelve leads electrocardiography,S-ECG)、右胸导联心电图(right precordial leads ECG,R-ECG)及Fontaine双极胸导联心电图(Fontaine bipolar precordial leads ECG,F-ECG)o Epsilon波判断标准为位于QRS波之后、sT段起始部的低波幅棘波、振荡波或平缓电位.结果 该组病例S-ECG、R-ECG及F-ECG对Epsilon波的检出率分别为37.5%、37.5%和50.0%,三种心电图记录方法之间Epsilon波检出率的比较差异无统计学意义(均为P＞0.05).其中1例Epsilon波仅见于S-ECG,3例仅见于R-ECG,5例仅见于F-ECG.S-ECG联合R-ECG的检出率为50.0%,S-ECG联合F-ECG的检出率为56.3%,三种记录方法的联合检出率为65.6%,S-ECG联合F-ECG的枪出率与S-ECG相比明显提高(P＜0.05),联合三种心电图记录方法的检出率与S-ECG相比有显著提高(P＜0.01).结论 联合使用S-ECG、R-ECG及F-ECG三种心电图记录方法,可以显著提高ARVC患者Epsilon波的检出率,且三种记录方法之间可以相互补充.     

Misdiagnosis of arrhythmogenic right ventricular dysplasia/cardiomyopathy

INTRODUCTION: Diagnosis of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) has major implications for the management of patients and their first-degree relatives. Diagnosis is based on a set of criteria proposed by the International Task Force for Cardiomyopathies. We report our experience in providing a re-evaluation for patients who previously have been diagnosed with ARVD/C. METHODS AND RESULTS: We studied 89 patients who requested a re-evaluation for diagnosis of ARVD/C at our center. Each of these patients had been diagnosed with ARVD/C at their initial evaluation. Each patient was re-evaluated with clinical history, physical examination, and noninvasive testing at our center. Invasive testing, which included electrophysiologic testing, right ventricular angiography, and endomyocardial biopsy, was performed when clinically indicated. Sixty (92%) of the 65 patients who had undergone magnetic resonance imaging (MRI) at an outside institution were reported to have an abnormal MRI consistent with ARVD/C. Among these patients, the only abnormality identified was the qualitative finding of intramyocardial fat/wall thinning in 46 patients. On re-evaluation, these qualitative findings were not confirmed. None of these 46 patients ultimately were diagnosed with ARVD/C. Among the entire patient group, only 24 (27%) of the 89 patients met the Task Force criteria for ARVD/C. CONCLUSION: This study demonstrates that the high frequency of "misdiagnosis" of ARVD/C is due to over-reliance on the presence of intramyocardial fat/wall thinning on MRI, incomplete diagnostic testing, and lack of awareness of the Task Force criteria. Diagnosis of ARVD/C cannot rely solely upon qualitative features on MRI.     

A casual spontaneous mutation as possible cause of the familial form of arrhythmogenic right ventricular cardiomyopathy (arrhythmogenic right ventricular dysplasia).

In a family affected by arrhythmogenic right ventricular cardiomyopathy (ARVC) the familial occurrence was investigated. All 14 members of two generations were investigated carefully, and only 2 (father and one son) members were affected. Both subjects had a massive form of the disease with relevant ventricular arrhythmias. Apart from the limitations of having investigated few subjects, this behavior suggests a genetic mutation appearing in the father and transmitted via an autosomal dominant trait.