The Use of Fontaine Leads in the Diagnosis of Arrhythmogenic Right Ventricular Dysplasia

We report a case of a 68‐year‐old man admitted to the emergency department with syncope preceded by rapid palpitations. His admission ECG demonstrated a sustained ventricular tachycardia (VT) originating from the right ventricular outflow tract (RVOT). This report highlights the importance of distinguishing ventricular tachycardia caused by arrhythmogenic right ventricular dysplasia (ARVD) from the more benign idiopathic RVOT‐VT. Furthermore, we demonstrate the utility of the Fontaine leads placement in increasing the sensitivity for uncovering epsilon waves, a highly specific electrocardiographic feature that increases diagnostic accuracy in patients with ARVD.     

Ablation of Ventricular Arrhythmias in Arrhythmogenic Right Ventricular Dysplasia

VT Ablation in Right Ventricular Dysplasia. Arrhythmogenic right ventricular dysplasia (ARVD) is a genetically determined myocardial disease characterized by fibrofatty replacement of the right ventricular wall. Ventricular tachyarrhythmias can be seen in the early stages of the disease, which is one of the most important causes of sudden death in young healthy individuals. Radiofrequency (RF) catheter ablation is an option for the treatment of medically refractory ventricular arrhythmias and it has shown to successfully abolish recurrent ventricular tachycardias (VT) as well as reduce the frequency in defibrillator therapies. However, variable acute and long‐term success rates have been reported. The current mapping and ablation techniques include activation and entrainment mapping during tolerated VT and substrate ablation using 3‐dimensional electroanatomic mapping systems. This article aims at providing a comprehensive review of RF catheter ablation of ventricular arrhythmias in the context of ARVD. (J Cardiovasc Electrophysiol, Vol. 21, pp. 473‐14, April 2010)     

Non-invasive Recognition of Arrhythmogenic Right Ventricular Dysplasia

ABSTRACT Arrhythmogenic right ventricular dysplasia causes ventricular arrhythmias and sometimes heart failure. The condition is easily overlooked, but once suspected, it may be diagnosed non-invasively. This is illustrated by the case reported. The clinical features of this syndrome are discussed, with special emphasis on the non-invasive findings.     

致心律失常性右室发育不良的电生理特性

致心律失常性右室发育不良在临床上主要表现为心律失常、猝死和心力衰竭。心电图上主要表现出(1)复极异常;(2)除极/传导异常;(3)室性心律失常。室性心动过速(室速)时舒张期的碎裂电位和心室病变部位的低电压区可以被看作是其诊断标准。Carto系统标测能发现病变区的准确位置、病变严重程度及病变范围。目前致心律失常性右室发育不良的临床治疗主要有:针对室速发生所采取的射频消融法,针对心力衰竭所采用的药物治疗及心脏移植手术,针对心脏猝死所采取的埋藏式心脏复律除颤器植入等。     

Prospective Study of Cardiac Sarcoid Mimicking Arrhythmogenic Right Ventricular Dysplasia

Introduction: Case studies indicate that cardiac sarcoid may mimic the clinical presentation of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C); however, the incidence and clinical predictors to diagnose cardiac sarcoid in patients who meet International Task Force criteria for ARVD/C are unknown.
Methods and Results: Patients referred for evaluation of left bundle branch block (LBBB)-type ventricular arrhythmia and suspected ARVD/C were prospectively evaluated by a standardized protocol including right ventricle (RV) cineangiography-guided myocardial biopsy. Sixteen patients had definite ARVD/C and four had probable ARVD/C. Three patients were found to have noncaseating granulomas on biopsy consistent with sarcoid. Age, systemic symptoms, findings on chest X-ray or magnetic resonance imaging (MRI), type of ventricular arrhythmia, RV function, ECG abnormalities, and the presence or duration of late potentials did not discriminate between sarcoid and ARVD/C. Left ventricular dysfunction (ejection fraction <50%) was present in 3/3 patients with cardiac sarcoid, but only 2/17 remaining patients with definite or probable ARVD/C (P = 0.01).
Conclusions: In this prospective study of consecutive patients with suspected ARVD/C evaluated by a standard protocol including biopsy, the incidence of cardiac sarcoid was surprisingly high (15%). Clinical features, with the exception of left ventricular dysfunction and histological findings, did not discriminate between the two entities.     

致心律失常性右室心肌病研究进展

致心律失常性右室心肌病以右心室心肌逐渐被脂肪和纤维组织替代而继发室性心律失常为主要特征的遗传性心肌病,多见于年轻人和运动员,可发生心力衰竭或心源性猝死。诊断依靠 ECG、形态学改变以及家族遗传病史等,治疗效果不佳,预后不良,是目前临床上危害严重的进行性心肌病变。在病因、遗传基础、诊疗手段、疾病进程等方面尚存在许多有待解决的问题,已引起国际各医疗机构的广泛关注,笔者现就其相关研究进展作一简介。     

Utility of SAECG in Arrhythmogenic Right Ventricle Dysplasia

Background: Arrhythmogenic right ventricular dysplasia (ARVD) is characterized by progressive replacement of RV myocardium with fibro‐adipose tissue thought to be responsible for the presence of late potentials (LP) detected by SAECG. The general consensus on the role of SAECG in the diagnosis and prognosis of patients with ARVD is lacking. The purpose of this systematic review was to better define the role of SAECG in ARVD. Methods: An extensive review of literature was done to specifically describe the prevalence of LP in ARVD and its determinants, explore the various options available to improve the diagnostic ability of SAECG, and provide recommendations for proper utilization of this technique. Results: LPs are frequent in ARVD (47–100%), and more prevalent in severe disease and in patients with documented spontaneous VT. SAECG is a useful test in following the characteristic evolutivity of the disease. 4–16% of normal family members of patients with ARVD also have abnormal SAECG results. Detection of LP in ARVD can be improved by employing a high‐pass filter of 25 Hz and specifically looking for changes in the Z leads. Conclusions: SAECG testing should be considered a standard part of the evaluation of patients with known or suspected ARVD. Further research is needed to confirm the value of SAECG testing in predicting arrhythmia risk and assessing the rate of disease progression, as well as to determine if greater prevalence of SAECG abnormalities in family members of patients with ARVD represents early detection of ARVD. The ongoing multidisciplinary study of right ventricular dysplasia will hopefully answer some of these questions.     

Usefulness of Biplanar Transesophageal Echocardiography in Arrhythmogenic Right Ventricular Dysplasia

This study evaluated the clinical usefulness of biplanar transesophageal echocardiography (TEE) in suspected arrhythmogenic right ventricular dysplasia (ARVD). Seven symptomatic subjects (3 male and 4 female: ages 18–64 years, mean 45) with clinical features of ARVD (typical ventricular arrhythmias) underwent comprehensive noninvasive assessment including transthoracic echocardiography (TTE), nuclear magnetic resonance (NMR), and TEE. Other systemic and cardiac diseases were reasonably excluded. TEE identified a significant right ventricular regional alteration in one subject with negative TTE and NMR, and nonsignificant abnormalities in two subjects with negative or no TTE and positive NMR. TEE confirmed the pathological findings detected by TTE in the four remaining patients and visualized several more abnormalities that approximately corresponded to NMR results. On the basis of these initial results, biplanar TEE appears to be comparable to NMR in the assessment of ARVD and a promising technique in identifying ARVD morphological alterations.     

Arrhythmogenic Right Ventricular Dysplasia: Clinical Results with Implantable Cardioverter Defibrillators

Arrhythmogenic right ventricular dysplasia is a clinical entitycharacterized by fatty infiltration of the right ventricle and left bundlemorphology ventricular tachycardia occurring in young patients. The mostcommon cause of death is tachyarrhythmic. Pharmacological andnonpharmacological therapies, including implantable cardioverterdefibrillators, have been used to treat the arrhythmias. However, rightventricular endocardial leads in this population may be associated with anincreased risk of perforation and suboptimal sensing and defibrillationefficacy due to the diseased right ventricle. We report on 12 patients witharrhythmogenic right ventricular dysplasia who were treated with implantablecardioverter defibrillators. The mean age was 31± 9 years (range15-48). Patients presented with presyncope (5), syncope (4), or cardiacarrest (3). All patients had electrocardiographic abnormalitiescharacteristic of the condition.Follow-up averaged 22 ± 13months (range 1-45). There was one sudden death at 1 month of follow-up. Ofthe 12 patients, 8 have had appropriate therapy delivered by the implantabledefibrillator. Six patients are currently on sotalol to reduce the frequencyof implantable defibrillator discharges. In conclusion, implantablecardioverter defibrillators with nonthoracotomy leads are feasible and safein patients with arrhythmogenic right ventricular dysplasia. The frequencyof appropriate therapy is high, supporting the use of implantablecardioverter defibrillators in this population.During programmedelectrical stimulation nine patients had sustained ventricular tachycardia,while three patients had no inducible arrhythmia. Transvenous leads wereplaced in nine patients. In these patients pacing thresholds weresignificantly higher, R-wave amplitudes were significantly lower, anddefibrillation thresholds were not significantly different than in a cohortof patients without right ventricular dysplasia. There were no acute orchronic complications of right ventricular lead placement.     

致心律失常性右室发育不良的研究进展

致心律失常性右室发育不良/心肌病是年轻人和运动员疲劳后猝死的主要原因,尽管病因不完全清楚,但基因异常是肯定的。病理学特点主要是右室心肌进行性被纤维脂肪组织替代。临床表现差别也比较大,可表现无症状性猝死,也可表现为发生心悸和(或)右心衰竭或全心衰竭。接近1/3病人12导联心电图出现右室晚激动波,平均信号心电图常表现为晚电位。二维超声心动图、磁共振显像、右室造影均可显示右室形态学异常。治疗主要是治疗和预防致命性心律失常,可根据病人情况采用药物治疗、植入型心律转复除颤器、射频消融治疗等。     

Conventional Electrocardiogram in Arrhythmogenic Right Ventricular Dysplasia-Cardiomyopathy and Idiopathic Right Ventricular Outflow Tract Tachycardia

Objective: Arrhythmogenic right ventricular dysplasia up to now is a rare cardiomyopathic entity with certain difficulties in clinical definition of diagnostic criteria. In 42 patients with major and minor criteria of arrhythmogenic right ventricular dysplasia and 25 patients with idiopathic ventricular arrhythmia, the role of conventional ECG in the diagnosis of arrhythmogenic right ventricular dysplasia was reevaluated. Methods: In standard 12-lead ECG, QRS duration was measured in limb lead D₁, and in V₁-V₆. A ratio of the sum of right (V₂+ V₃) and left (V₄+ V₅) was calculated. T wave inversions, Epsilon wave, and mechanisms of advancing right bundle branch block were analyzed. Results: In 39 out of 42 patients (93%) with the diagnosis of arrhythmogenic right ventricular dysplasia, a ratio of right and left precordial QRS duration of >1.2, a maximum right precordial QRS duration of > 100 ms in 10 cases (26%) and >110 ms in 29 cases (74%) could be found. Incomplete right bundle branch block with right precordial T inversions was found in one case. The ECG in two patients revealed a precordial R/S transition in V₁ or V₂; in all other cases, R/S transition was localized in V₃ or V₄. R peak time was normal (< 0.04 s) in all cases, a “notching” or “slurring” of the S wave was striking in 16 cases. T wave inversions were found in 27 cases and definite Epsilon wave in only one case. Although incomplete right bundle branch block and certain preforms could also be disclosed in four patients with idiopathic right ventricular outflow tract (RVOT) tachycardia, localized right precordial QRS prolongation could be excluded in all but one of these cases. Localized right precordial QRS duration prolongation in one case was probably due to a rotation of the heart with a precordial R/S transition between V₁ and V₂. Conclusion: Localized right precordial QRS prolongation in a normal precordial R/S transition: (a) seems to be the most important aspect of arrhythmogenic right ventricular dysplasia at conventional ECG, with a sensitivity of 93% and a specificity of 96% in order to distinguish idiopathic RVOT tachycardia; (b) can appear with (64%) or without (36%) secondary T wave inversions; and (c) is due to a “parietal” block sparing the specialized conducting system.     

致心律失常性右心室心肌病累及左心室的临床病理分析

目的:分析9例经病理证实以左心室受累为主的致心律失常性右心室心肌病(ARVC)的临床病理特征,提高对左心室受累致ARVC的认识。方法:回顾49例心脏移植中9例经病理证实为左心室受累为主的ARVC患者的一般特征、猝死和心肌病家族史、临床症状和病程、药物治疗史、心电图、24小时动态心电监测(Holter)、超声心动图、心血池、静态心肌显像、心脏磁共振成像、冠状动脉造影及受体心脏大体和组织学病理特征。结果:9例患者平均年龄13~54(40.4±15.9)岁,女性5例,男性4例。心悸胸闷病史0.33~20年,平均(9.1±8.9)年,晕厥史2例,有电除颤史6例,胺碘酮治疗5例。2例有猝死家族史。ARVC特征性心电图异常包括V1~3/4~6导联QRS间期>1.2(占0%),有ε波(占44.4%),胸前导联T波倒置(占33.3%)。9例24小时动态心电监测中4例有阵发性心房颤动,其中2例合并心房扑动;2例未服胺碘酮者室性早搏>1000次/24h,其余7例(5例服用胺碘酮)室性早搏均<1000次/24h,室性早搏形态平均(3.3±1.1)种/24h。9例术前超声心动图显示平均右心室内径(32.6±6.7)mm,左心房内径(37.1±10.3)mm,左心室舒张末径(57.3±11.9)mm,左心室射血分数0.26±0.09。7例患者术前心脏磁共振成像显示,5例可见异常高强度信号区域,5例可见右心室和右心房扩大,4例可见右心室壁瘤样突出。8例术前用Swan-Gans导管作血流动力学监测:平均右心室压(19.3±8.3)mmHg(1mmHg=0.133kPa),平均肺毛细血管楔压(15.6±7.7)mmHg,平均心脏指数(2.0±0.4)L/(min.m2),平均肺血管阻力(267.8±167.6)dyn.s.cm-5。9例病理特征为右心室腔显著扩大7例,右心室壁整体变薄6例,右心室流出道最薄处<1mm。左心室均有受累,显著扩张8例。左、右心室壁均被不同范围的纤维和脂肪组织替代。结论:虽然ARVC累及双心室者难以与扩张型心肌病鉴别,但是结合临床和影像资料,特别是心脏磁共振成像,可提高ARVC诊断的准确性。     

The Prognostic Value of Right Ventricular Deformation Imaging in Early Arrhythmogenic Right Ventricular Cardiomyopathy

Objectives

The aim of this study was to investigate the prognostic value of echocardiographic deformation imaging in arrhythmogenic right ventricular cardiomyopathy (ARVC) to optimize family screening protocols.