Arrhythmogenic right ventricular dysplasia presenting as right ventricular outflow tract tachycardia.

A case of a 51-year old male is presented. A left bundle branch block inferior axis tachycardia was manifest. At electrophysiological study this tachycardia was inducible and was ablated in the septal right ventricular outflow tract (RVOT). Two other tachycardias were identified both with right bundle branch block (RBBB) morphology raising the suspicion of diffuse pathology. Arrythmogenic right ventricular dysplasia (ARVD) was confirmed by right ventricular angiography and magnetic resonance imaging (MRI). An implantable cardioverter defibrillator (ICD) was implanted and an appropriate shock was later delivered.     

Arrhythmogenic right ventricular dysplasia/cardiomyopathy. A review and update

The arrhythmogenic right ventricular dysplasia/cardiomyopathy is an important cause of sudden arrhythmic death, often exertional, in young individuals and athletes. Although the aetiology remains partially unknown, genetic abnormalities have been demonstrated. Reported prevalence is 1 in 5000 individuals but it is considered there are many non-diagnosed cases.

The characteristic pathologic finding is the progressive fibro-fatty replacement of the right ventricular myocardium. The clinical manifestations vary from asymptomatic patients with an episode of sudden cardiac death as first symptom to chronically symptomatic patients with recurrent palpitations and/or right or biventricular failure.

Approximately a third of the patients show the characteristic Epsilon wave in the 12-lead ECG which is a useful screening test. Signal-averaged ECG frequently demonstrates late potentials. The two-dimensional echocardiography, magnetic resonance imaging, computerized tomography and right ventricular cineangiography show morphologic abnormalities in the right ventricle.

Therapy is directed to prevent and/or treat malignant ventricular tachyarrhythmias with medications, implantable cardioverter defibrillator and radiofrequency ablation in selected cases.     

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。     

Arrhythmogenic Right Ventricular Cardiomyopathy

Abstract Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a major cause of sudden cardiac death and ventricular tachyarrhythmias in young, apparently healthy individuals and athletes. Myocardial atrophy with subsequent fibrofatty replacement predominantly affects right ventricular myocardium and results in global and regional dysfunction as well as areas of slow conduction and dispersion of refractoriness which are prerequisites for reentrant ventricular tachyarrhythmias.Patients affected with ARVC should be excluded from competitive sports and vigorous training. To provide optimal treatment, a detailed diagnostic evaluation and risk stratification are mandatory. Tailored treatment strategies aim at the suppression or effective termination of recurrent ventricular tachyarrhythmias and prevention of sudden death by antiarrhythmic drug therapy, catheter ablation, or implantation of a cardioverter defibrillator (ICD).Antiarrhythmic drugs may be used as a stand-alone treatment to suppress ventricular tachycardia (VT) recurrences in patients with ARVC and low risk of sudden death. Sotalol (preferred) or amiodarone in combination with -blockers showed the highest efficacy rates. In patients at higher risk, an ICD should be implanted and antiarrhythmic drugs be used only as an adjunct to prevent or suppress frequent VT recurrences and ICD discharges.Catheter ablation using conventional or electroanatomic mapping techniques yields good acute results for eliminating the targeted arrhythmia substrate. However, during the progressive long-term course of ARVC, VT recurrences from new arrhythmia foci are frequent and therefore limit the curative value of catheter ablation. In patients with frequent VT recurrences and ICD discharges, however, catheter ablation plays an important role as a palliative and adjunctive treatment option for arrhythmia suppression.ICD therapy has been increasingly used for secondary and also primary prevention of sudden death in patients with ARVC. In secondary prevention, the ICD has shown to improve the long-term prognosis of patients at high risk of sudden death by effective termination of life-threatening recurrences of ventricular tachyarrhythmias. However, adequate lead placement may be difficult and lead-related complications during long-term follow-up must be taken into account. The role of ICD therapy for primary prevention of sudden death in ARVC is not yet adequately defined.Ongoing international registries will provide important additional data to improve risk stratification and refine treatment algorithms in order to select the best individual treatment for arrhythmia suppression and prevention of sudden death in patients with ARVC.     

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.)     

Noninvasive recognition of the parchment right ventricle (Uhl's anomaly arrhythmogenic right ventricular dysplasia) syndrome

The case of a 53-year-old man with right heart failure, selective enlargement of the right-sided cardiac chambers, and recurrent sustained ventricular tachycardia is presented. Echocardiographic, radionuclide ventriculographic, and angiographic studies were typical of the right ventricular abnormalities in Uhl's anomaly; electrocardiographic and electrophysiologic findings were those of arrhythmogenic right ventricular dysplasia. Features of this unusual cause of cardiac failure and ventricular arrhythmias in the adult are reviewed, and compared to previous reports of both Uhl's anomaly and arrhythmogenic right ventricular dysplasia. We postulate that these two syndromes are manifestations of a single, presumably congenital, pathophysiologic process—the “parchment right ventricle” syndrome.     

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.     

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.     

Arrhythmogenic ventricular cardiomyopathy:A paradigm shift from right to biventricular disease

Arrhythmogenic ventricular cardiomyopathy(AVC) isgenerally referred to as arrhythmogenic right ventricu-lar(RV) cardiomyopathy/dysplasia and constitutesan inherited cardiomyopathy.Affected patients maysuccumb to sudden cardiac death(SCD),ventriculartachyarrhythmias(VTA) and heart failure.Geneticstudies have identified causative mutations in genesencoding proteins of the intercalated disk that lead toreduced myocardial electro-mechanical stability.Theterm arrhythmogenic RV cardiomyopathy is somewhatmisleading as biventricular involvement or isolated leftventricular(LV) involvement may be present and thus abroader term such as AVC should be preferred.The di-agnosis is established on a point score basis accordingto the revised 2010 task force criteria utilizing imagingmodalities,demonstrating fibrous replacement throughbiopsy,electrocardiographic abnormalities,ventricu-lar arrhythmias and a positive family history includingidentification of genetic mutations.Although severarisk factors for SCD such as previous cardiac arrest,syncope,documented VTA,severe RV/LV dysfunctionand young age at manifestation have been identified,risk stratification still needs improvement,especially inasymptomatic family members.Particularly,the roleof genetic testing and environmental factors has to befurther elucidated.Therapeutic interventions include re-striction from physical exercise,beta-blockers,sotalol,amiodarone,implantable cardioverter-defibrillators andcatheter ablation.Life-long follow-up is warranted insymptomatic patients,but also asymptomatic carriersof pathogenic mutations.     

Arrhythmogenic right ventricular dysplasia presenting with ventricular tachycardia in a father and son

A father and his son presented with ventricular tachycardia of left bundle-branch block configuration, two years apart. The patients had no clinical signs of right or left ventricular dysfunction. The diagnosis of arrhythmogenic right ventricular dysplasia was based on right ventricular angiographic and radionuclide findings. Microscopic sections obtained at surgery for the ventricular tachycardia in the father revealed abnormal infiltration of fat and focal fibrosis in the right ventricular myocardium, confirming the diagnosis. The importance of thorough evaluation of right and left ventricular function and structure in patients with ventricular tachycardia of right ventricular origin is emphasized. Currently available diagnostic techniques and management are presented.     

Ventricular dimensions and wall motion assesed by echocardiography in patients with arrhythmogenic right ventricular dysplasia

Twenty patients with arrhythmogenic right ventricular dysplasia(ARVD) and 20 helthy volunteers underwent cross-sectional echocardiographicexamination for the assessment of ventricular dimensions andwall motion. Right ventricular cavity diameters and wall segmentsfrom the inflow and outflow tracts and the right ventricularbody. The measurements eroor for measuring cavity dimensions was lowthroughout and the reproducibility of wall motion scoring washigh in both the normal subjects and the patients. All exceptone patient had increased dimensions and/or abnormal wall motionin the right ventricle. The right ventricular inflow tract wasdilated in nine patients, the outflow tract in 11 patients andthe short-or long-axis diameters of the right ventricular bodywere increased in seven patients, Right ventricular wall motionabnormalities, being the most frequent finding, ranged frommild hypokinesia only to dyskinesia or sacculations, and werefairly evenly distributed among the segments studied. Left ventricularabnormalities, found in eight patients, were generally mild.Cross-sectional echocardiology thus provides highly reproduciblemeasurements of right ventricular size and contraction patternseven in patients with wall shape deformities, and is théreforea feasible non-invasive method for the evaluation of right-sidedmyocardial abnormalities in patients with ARVD. The diagnosticaccuracy of this technique warrants further clarification.     

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.     

Arrhythmogenic right ventricular cardiomyopathy: From genetics to diagnostic and therapeutic challenges

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic disease characterized by myocyte loss and fibro-fatty tissue replacement. Diagnosis of ARVC remains a clinical challenge mainly at its early stages and in patients with minimal echocardiographic right ventricular (RV) abnormalities. ARVC shares some common features with other cardiac diseases, such as RV outflow ventricular tachycardia, Brugada syndrome, and myocarditis, due to arrhythmic expressivity and biventricular involvement. The identification of ARVC can be often challenging, because of the heterogeneous clinical presentation, highly variable intra- and inter-family expressivity and incomplete penetrance. This genotype-phenotype “plasticity” is largely unexplained. A familial history of ARVC is present in 30% to 50% of cases, and the disease is considered a genetic cardiomyopathy, usually inherited in an autosomal dominant pattern with variable penetrance and expressivity; in addition, autosomal recessive forms have been reported (Naxos disease and Carvajal syndrome). Diagnosis of ARVC relays on a scoring system, with major or minor criteria on the Revised Task Force Criteria. Implantable cardioverter defibrillators (ICDs) are increasingly utilized in patients with ARVC who have survived sudden death (SD) (secondary prevention). However, there are few data available to help identifying ARVC patients in whom the prophylactic implantation of an ICD is truly warranted. Prevention of SD is the primary goal of management. Pharmacologic treatment of arrhythmias, catheter ablation of ventricular tachycardia, and ICD are the mainstay of treatment of ARVC.     

Arrhythmogenic right ventricular cardiomyopathy

Arrythmogenic right ventricular (RV) cardiomyopathy (ARVC) is a cardiomyopathy characterized pathologically by fibrofatty replacement primarily of the RV and clinically by life-threatening ventricular arrhythmias in apparently healthy young people. The prevalence of the disease has been estimated at 1 in 5,000 individuals, although this estimate will likely increase as awareness of the condition increases among physicians. Arrythmogenic RV cardiomyopathy is recognized as a cause of sudden death during athletic activity because of its association with ventricular arrhythmias that are provoked by exercise-induced catecholamine discharge. Diagnosis may be difficult because many of the electrocardiographic abnormalities mimic patterns seen in normal children, and the disease often involves only patchy areas of the RV. For this reason, international diagnostic criteria for ARVC were proposed by an expert consensus panel in 1996. Treatment is directed to preventing life-threatening cardiac arrhythmias with medications and the use of implantable defibrillators. This article will present in detail the etiology, clinical presentation, diagnosis and management of this condition.     

致心律失常性右室心肌病的研究进展

致心律失常性右室心肌病或致心律失常性右室发育不良/心肌病是一种主要累及右室的心肌疾病,表现为室性心动过速和猝死。新近研究证明这种疾病不是一种少见疾病,患病率约为1/1000,50%~80%有家族史,是一种常染色体遗传性疾病。1994年的诊断标准导致诊断率较低。目前对诊断指标进行了修改,如胸前导联QRS时限延长。通过改进ECG记录方式可以发现更多的epsilon波。应用新的诊断标准将发现更多的有症状和无症状致心律失常性右室心肌病的患者。基因筛查特别是plakophil-in-2突变筛查将成为疾病重要的早期诊断工具。致心律失常性右室心肌病的治疗应在改变生活方式(包括限制参加竞技运动)的基础上,根据病情应用β阻滞剂、胺碘酮、索他洛尔和/或ICD治疗预防猝死。     

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.