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.     

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.     

Predictors of appropriate implantable defibrillator therapies in patients with arrhythmogenic right ventricular dysplasia

BACKGROUND: Arrhythmogenic right ventricular dysplasia (ARVD) is an inherited cardiomyopathy characterized by ventricular arrhythmias and sudden cardiac death. The risk factors for sudden death and indications for implantable cardioverter-defibrillator (ICD) placement in patients with ARVD are not well defined. OBJECTIVES: The purpose of this study was to determine which clinical and electrophysiologic variables best predict appropriate ICD therapies in patients with ARVD. Particular attention focused on whether the ICD was implanted for primary or second prevention. METHODS: We enrolled 67 patients (mean age 36 +/- 14 years) with definite or probable ARVD who had undergone ICD placement. Appropriate ICD therapies were recorded, and Kaplan-Meier analysis was used to compare the event-free survival time between patients based upon the indication for ICD placement (primary vs secondary prevention), results of electrophysiologic testing, and whether the patient had probable or definite ARVD. RESULTS: Over a mean follow-up of 4.4 +/- 2.9 years, 40 (73%) of 55 patients who met task force criteria for ARVD and 4 (33%) of 12 patients with probable ARVD had appropriate ICD therapies for ventricular tachycardia/ventricular fibrillation (VT/VF; P = .027). Mean time to ICD therapy was 1.1 +/- 1.4 years. Eleven of 28 patients who received an ICD for primary prevention (39%) and 33 of 35 patients who received an ICD for secondary prevention (85%) experienced appropriate ICD therapies (P = .001). Electrophysiologic testing did not predict appropriate ICD interventions in patients who received an ICD for primary prevention. Fourteen patients (21%) received ICD therapy for life-threatening (VT/VF >240 bpm) arrhythmias. There was no difference in the incidence of life-threatening arrhythmias in the primary and secondary prevention groups (P = .29). CONCLUSION: Patients who meet task force criteria for ARVD are at high risk for sudden cardiac death and should undergo ICD placement for primary and secondary prevention, regardless of electrophysiologic testing results. Further research is needed to confirm that a low-risk subset of patients who may not require ICD placement can be identified.     

Thromboembolic complications in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy.

AIMS: Incidence and clinical presentation of thromboembolic complications in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) were analysed. In reports on ARVD/C, thromboembolism is rarely mentioned. The possible risk factors are: right ventricle (RV) dilatation, aneurysms, and wall motion abnormalities. METHODS AND RESULTS: A group of 126 patients (89 male, 37 female, aged 43.6+/-14.3) with ARVD/C was retrospectively analysed for the presence of thromboembolic complications. The mean follow-up period was 99+/-64 months. Thromboembolic complications, i.e. pulmonary embolism (n=2), RV outflow tract thrombosis with severe RV failure (n=1), and cerebrovascular accident associated with atrial fibrillation (n=2) were observed in 4% of the patients. Spontaneous echogenic contrast was observed in seven patients with severe damage to RV. In four of them supraventricular arrhythmias resulting in heart failure were reported. Annual incidence of thromboembolic complications was 0.5/100 patients. CONCLUSIONS: (i) ARVD/C may be complicated by thrombosis. Annual incidence of such complications is significantly lower than reported for left ventricle failure. (ii) Anticoagulation should be used in ARVD/C patients with large, hypokinetic RV and slow blood flow. (iii) Patients with severe forms of ARVD/C, thrombus formation in the RV and/or spontaneous echocardiographic contrast are at higher risk of a poor outcome.     

Histologic abnormalities of the left ventricle in a patient with arrhythmogenic right ventricular dysplasia

Summary Right ventricular histologic abnormalities have been described in association with arrhythmogenic right ventricular dysplasia, but the cause of the disease is unknown. Identical abnormalities were noted in endomyocardial biopsy specimens from the right and left ventricles of a 20-year-old male patient with the clinical syndrome of arrhythmogenic right ventricular dysplasia. Left ventricular function was normal at rest and during bicycle exercise. Eighteen months previously, he had shown clinical and serologic evidence of mycoplasmal myocarditis. Arrhythmogenic right ventricular dysplasia may represent predominant involvement of the right ventricle in a generalized cardiomyopathic process, possibly as a consequence of healed myocarditis.     

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.     

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.     

Systemic sclerosis complicated by arrhythmogenic right ventricular dysplasia that was misinterpreted as pulmonary arterial hypertension

Abstract

A 58-year old Japanese woman who had been diagnosed with and managed for systemic sclerosis (SSc) with pulmonary arterial hypertension died suddenly. However, the autopsy revealed marked right ventricular dilatation, and the myocardium had been replaced by fatty tissue. These findings were consistent with arrhythmogenic right ventricular dysplasia (ARVD). A literature search identified nine cases of SSc with ARVD in Japan, including this case; this number is significantly higher than the value estimated from the prevalences of ARVD and SSc in Japan, suggesting an association between these two rare diseases.     

Arrhythmogenic right ventricular dysplasia

Abstract A 23-year-old man presented with recurrent exercise-induced ventricular tachycardia (VT), complicated by systemic embolisation. Catecholamine - sensitive VT was reproduced on exercise testing and programmed electrical stimulation, displaying features suggestive of enhanced automaticity as well as re-entry. Both 2D-echocardiography and gated heart pool scan showed localised dyskinetic bulging in the right ventricle. A diagnosis of arrhythmogenic right ventricular dysplasia was made. This condition should be excluded in all young patients with otherwise unexplained ventricular arrhythmias. (Aust NZ J Med 1991; 21: 451–453.)     

The arrhythmogenic right ventricle. Dysplasia versus cardiomyopathy

Summary Twenty-four patients presenting with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ventricular tachycardia of right ventricular origin associated with structural abnormalities of the right ventricle) were divided into two groups with left ventricular ejection fraction (LVEF) above or below 45%. The distribution of LVEF in the group with LVEF below 45% was comparable with the distribution in 6 patients with idiopathic dilated cardiomyopathy who had ventricular tachycardia originating in the left ventricle (P = 0.2). They also had the same unfavorable long-term prognosis. Therefore, it is suggested that the term, arrhythmogenic right ventricular cardiomyopathy (ARVC), be restricted to patients with a LVEF below 45%. Histological data obtained in the ARVC group showed signs of acute or chronic myocarditis (in the right and left ventricles). It can be hypothesized that patients with arrhythmogenic right ventricular dysplasia (ARVD) may be prone to develop infectious myocarditis. In patients in whom an abnormal host immune response had been seen, progressive deterioration of right and left ventricular function could be observed. This pattern may be superimposed on the genetically determined background of ARVD. This could explain the wide spectrum of clinical presentation observed in patients with tachycardia originating in an abnormal right ventricle.Presented at the ISFC International Symposium on Cardiomyopathies, Warsaw (Poland) October 1993     

A novel treatment strategy for therapy refractory ventricular arrhythmias in the setting of arrhythmogenic right ventricular dysplasia.

Arrhythmogenic right ventricular dysplasia (ARVD) is a major cause of ventricular tachycardia and cardiac arrest in young adults. The ideal management of this genetic disorder is individual. The treatment options are antiarrhythmic drug therapy, transcatheter radiofrequency catheter ablation, implantable cardioverter defibrillator therapy, and surgical treatment [Kies P, Bootsma M, Bax J, Schalij MJ, van der Wall EE. Arrhythmogenic right ventricular dysplasia/cardiomyopathy: screening, diagnosis, and treatment. Heart Rhythm 2006;3:225-34; Verma A, Kilicaslan F, Schweikert RA et al. Short- and long-term success of substrate-based mapping and ablation of ventricular tachycardia in arrhythmogenic right ventricular dysplasia. Circulation 2005;111:3209-16]. In the following, we describe a unique case of a young patient, presenting with therapy refractory ventricular arrhythmias in the setting of ARVD, who following failed catheter ablations, has been successfully treated with beating heart cryoablation.     

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。     

QT dispersion in patients with arrhythmogenic right ventricular dysplasia.

AIMS: Arrhythmogenic right ventricular dysplasia is a rarely diagnosed cardiomyopathy, but a frequent cause of ventricular arrhythmia and sudden cardiac death. QT interval dispersion, measured as an interlead variability of QT, is a marker of dispersion of ventricular repolarization and, hence, of electrical instability. The present study was conducted to assess the occurrence of QT dispersion and its modulation during treatment with sotalol.Methods Twenty-five patients with the diagnosis of arrhythmogenic right ventricular dysplasia were studied retrospectively. Fourteen patients were considered low risk for malignant ventricular arrhythmia and sudden cardiac death, and 11 high risk due to documented sustained ventricular arrhythmia, cardiac arrest, or sudden cardiac death. Twenty five healthy volunteers served as control subjects. RESULTS: Dispersion of repolarization was significantly higher in patients than in control subjects (QTd and JTd: P<0.05). Dispersion of repolarization was equal in patients both with and without malignant arrhythmias. There was no significant change in dispersion after treatment with sotalol. Adjacent QT dispersion between leads V3-V4, V4-V5 and V5-V6, respectively, was higher in patients than in control subjects (P<0. 05), while no differences were seen in leads V1-V2 and V2-V3. CONCLUSION: QT interval dispersion is increased in patients with arrhythmogenic right ventricular dysplasia. However, the degree of dispersion is not related to the severity of symptoms, nor is it influenced by treatment with sotalol.     

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。     

Ventricular tachycardia mapping and ablation in arrhythmogenic right ventricular cardiomyopathy/dysplasia:Lessons Learned

Arrhythmogenic right ventricular cardiomyopathy/dysplasia(ARVC/D) is primarily believed to be an inherited cardiomyopathy that subsequently results in significant myocardial fibrosis. The arrhythmogenic consequences that result from the development of fibrosis are similar to other nonischemic cardiomyopathies, but the unique endocardial-epicardial disease process of ARVC/D requires a specialized approach for arrhythmia treatment in the electrophysiology laboratory. Although the association between ARVC/D and development of ventricular arrhythmias has become increasingly clear over the last 2 decades, our understanding of the arrhythmia mechanisms, underlying electrophysiologic substrate, and treatment strategies were significantly limited. Prospective studies performed in the electrophysiology laboratory allowed detailed characterization of the electrophysiologic and electroanatomic substrate underlying ventricular tachycardia in patients with ARVC/D. Thishas allowed clinician scientists to better characterize the arrhythmia mechanism and develop the necessary strategies to perform successful catheter ablation. Early in this experience, catheter ablation was considered a limited and largely unsuccessful treatment for patients experiencing painful and recurrent defibrillator therapy. Through our increased understanding of the disease process, catheter ablation has evolved to become an effective and preferred therapy for a majority of these patients. Our understanding of the disease and necessary approaches to provide successful treatment continues to evolve as the clinical experience grows. This article will review these important insights from the electrophysiology laboratory and how application of this knowledge has facilitated the development of a methodical approach to successfully perform ventricular tachycardia ablation in patients with ARVC/D.     

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。     

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.