Catheter ablation of ventricular tachycardia in patients with arrhythmogenic right ventricular cardiomyopathy and biventricular involvement.

AIMS: Catheter ablation of ventricular tachycardia (VT) improves VT-free survival in 'classic' arrhythmogenic right ventricular cardiomyopathy (ARVC). This study aims to investigate electrophysiological features and ablation outcomes in patients with ARVC and biventricular (BiV) involvement. METHODS AND RESULTS: We assembled a retrospective cohort of definite ARVC cases with sustained VTs. Patients were divided into the BiV (BiV involvement) group and the right ventricular (RV) (isolated RV involvement) group based on the left ventricular systolic function detected by cardiac magnetic resonance. All patients underwent electrophysiological mapping and VT ablation. Acute complete success was non-inducibility of any sustained VT, and the primary endpoint was VT recurrence. Ninety-eight patients (36 ± 14 years; 87% male) were enrolled, including 50 in the BiV group and 48 in the RV group. Biventricular involvement was associated with faster clinical VTs, a higher VT inducibility, and more extensive arrhythmogenic substrates (all P < 0.05). Left-sided VTs were observed in 20% of the BiV group cases and correlated with significantly reduced left ventricular systolic function. Catheter ablation achieved similar acute efficacy between these two groups, whereas the presence of left-sided VTs increased acute ablation failure (40 vs. 5%, P = 0.012). Over 51 ± 34 months [median, 48 (22-83) months] of follow-up, cumulative VT-free survival was 52% in the BiV group and 58% in the RV group (P = 0.353). A multivariate analysis showed that younger age, lower RV ejection fraction (RVEF), and non-acute complete ablation success were associated with VT recurrence in the BiV group. CONCLUSION: Biventricular involvement implied a worse arrhythmic phenotype and increased the risk of left-sided VTs, while catheter ablation maintained its efficacy for VT control in this population. Younger age, lower RVEF, and non-acute complete success predicted VT recurrence after ablation.

A unique cuff-sewing method to implant heartmate3 LVAD for arrhythmogenic right ventricular cardiomyopathy, facilitated by 3D-printing heart model.

Implantation of left ventricular assist device (LVAD) for arrhythmogenic right ventricular (RV) cardiomyopathy is challenging associated with small LV cavity, laterally dislocated LV apex, thin and fragile RV free wall. A 43-year-old male with more than 10 years of medical treatment developed congestive heart failure related to biventricular failure. Durable LVAD was indicated to prevent further deterioration of the RV function, which would be exacerbated by progression of LV dysfunction. To simulate surgery, we printed-out a 3D heart model based on enhanced CT scanning study to identify the optimal coring position in the LV apex, by which the inflow directs the mitral valve. We then found that the mini-cuff of the HeartMate3 should be fixed in the paper-thin RV free wall by the usual cuff-sewing method. In the surgery, after the coring as planned, 5 pairs of interrupted sutures on the medial side were passed from the luminal side of the LV and then to the mini-cuff, and the lateral side of the mini-cuff was fixed with a continuous sutures, not to sew into the RV wall. The surgery was completed without complications with a good hemodynamics. The 3D heart model facilitated this unique method, indicating a usefulness of printed-out heart model for cases with unusual cardiac anatomy, which needs implantation of durable LVAD.

Efficacy of catheter ablation for premature ventricular contractions in arrhythmogenic right ventricular cardiomyopathy.

BACKGROUND: Premature ventricular contractions (PVCs) may be found in any stage of arrhythmogenic right ventricular cardiomyopathy (ARVC) and have been associated with the risk of sustained ventricular tachycardia (VT). OBJECTIVE: To investigate the role of PVC ablation in ARVC patients. METHODS: We studied consecutive ARVC patients who underwent PVC ablation due to symptomatic high PVC burden. Mean daily PVC burden and antiarrhythmic drug (AAD) use were assessed before and after the procedure. Complete long-term success was defined as more than 80% reduction in PVC burden off of membrane-active AADs. RESULTS: Eight patients (37 ± 15 years; 4 males) underwent PVC ablation. The mean daily PVC burden before ablation ranged from 5.4% to 24.8%. A total of 7 (87.5%) patients underwent epicardial ablation. Complete acute elimination of PVCs was achieved in 4 (50%) patients (no complications). The mean daily PVC burden variation ranged from an 87% reduction to a 26% increase after the procedure. Over a median follow-up of 345 days (range: 182-3004 days), only one (12.5%) patient presented complete long-term success, and 6 (75%) patients either maintained or increased the need for Class I or Class III AADs. A total of 2 (25%) patients experienced sustained VT for the first time following the ablation procedure, requiring repeat ablation. No death or heart transplantation occurred. CONCLUSION: PVC ablation was not associated with a consistent reduction of the PVC burden in ARVC patients with symptomatic, frequent PVCs. PVC ablation may be reserved for highly symptomatic patients who failed AADs. Additional investigation is required to improve the efficacy of PVC ablation in ARVC patients.

Clinical significance of J waves with respect to substrate characteristics and ablation outcomes in patients with arrhythmogenic right ventricular cardiomyopathy.

AIMS: J-wave syndrome in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) has been linked to an increased risk of ventricular arrhythmia. We investigated the significance of J waves with respect to substrate manifestations and ablation outcomes in patients with ARVC. METHODS AND RESULTS: Forty-five patients with ARVC undergoing endocardial/epicardial mapping/ablation were studied. Patients were classified into two groups: 13 (28.9%) and 32 (71.1%) patients with and without J waves, respectively. The baseline characteristics, electrophysiological features, ventricular substrate, and recurrent ventricular tachycardia/fibrillation (VT/VF) were compared. Among the 13 patients with J waves, only the inferior J wave was observed. More ARVC patients with J waves fulfilled the major criteria of ventricular arrhythmias (76.9% vs. 21.9%, P = 0.003). Similar endocardial and epicardial substrate characteristics were observed between the two groups. However, patients with J waves had longer epicardial total activation time than those without (224.7 ± 29.9 vs. 200.8 ± 21.9 ms, P = 0.005). Concordance of latest endo/epicardial activation sites was observed in 29 (90.6%) patients without J waves and in none among those with J waves (P < 0.001). Complete elimination of endocardial/epicardial abnormal potentials resulted in the disappearance of the J wave in 8 of 13 (61.5%) patients. The VT/VF recurrences were not different between ARVC patients with and without J waves. CONCLUSION: The presence of J waves was associated with the discordance of endocardial/epicardial activation pattern in terms of transmural depolarization discrepancy in patients with ARVC.

Arrhythmogenic Right Ventricular Cardiomyopathy Diagnosed during Hospitalization for Cardiac Arrest.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetically mediated cardiomyopathy charac-terized by progressive myocardial loss of the right ventricle and its replacement by fibrofatty tissue, causing dyskinesia, aneurysm, and/or arrhythmia. The prevalence of ARVC is estimated to be 1 in 2,000-5,000, with the condition accounting for up to 20% of sudden cardiac deaths in individuals < 35 years old. This report describes the case of 61-year-old Japanese who was diagnosed with ARVC after cardiac arrest (CA) and successful resusci-tation. After the sudden CA, the restoration of spontaneous circulation was achieved with appropriate resusci-tation, followed by the introduction of target temperature management in the intensive care unit. He was diag-nosed with ARVC based on angiography and histology results. An ICD (implantable cardioverter-defibrillator) was implanted, and he was discharged without neurological sequelae 1 month post-CA. ARVC is an important cause of sudden CA, and successfully resuscitated patients with right ventricular dilation should undergo testing to rule out ARVC.

Endo-epicardial ablation vs endocardial ablation for the management of ventricular tachycardia in arrhythmogenic right ventricular cardiomyopathy: A systematic review and meta-analysis.

BACKGROUND: The pathologic process of ARVC (arrhythmogenic right ventricular cardiomyopathy) typically originates in the epicardium or subepicardial layers with progression toward endocardium. However, in the most recent ARVC international task force consensus statement, epicardial ventricular tachycardia (VT) ablation is recommended as a Class I indication only in patients with at least one failed endocardial VT ablation attempt. OBJECTIVE: The aim of this meta-analysis is to assess the outcomes of ARVC patients undergoing combined endo-epicardial VT ablation, as compared to endocardial ablation alone. METHODS: A systematic review of PubMed, Embase, and Cochrane was performed for studies reporting clinical outcomes of endo-epicardial VT ablation vs endocardial-only VT ablation in patients with ARVC. Fixed-Effect model was used if I2 < 25 and the Random-Effects Model was used if I2 ≥ 25%. RESULTS: Nine studies consisting of 452 patients were included (mean age 42.3 ± 5.7 years; 70% male). After a mean follow-up of 48.1 ± 21.5 months, endo-epicardial ablation was associated with 42% relative risk reduction in VA recurrence as opposed to endocardial ablation alone (risk ratio [RR], 0.58; 95% confidence interval [CI], 0.45-0.75; P < .0001). No significant differences were noted between endo-epicardial and endocardial VT ablation groups in terms of all-cause mortality (RR, 1.19; 95% CI, 0.03-47.08; P = .93) and acute procedural complications (RR, 5.39; 95% CI, 0.60-48.74; P = .13). CONCLUSIONS: Our findings suggest that in patients with ARVC, endo-epicardial VT ablation is associated with a significant reduction in VA recurrence as opposed to endocardial ablation alone, without a significant difference in all-cause mortality or acute procedural complications.

Automatic Detection of Slow Conducting Channels during Substrate Ablation of Scar-Related Ventricular Arrhythmias.

BACKGROUND: Voltage mapping allows identifying the arrhythmogenic substrate during scar-related ventricular arrhythmia (VA) ablation procedures. Slow conducting channels (SCCs), defined by the presence of electrogram (EGM) signals with delayed components (EGM-DC), are responsible for sustaining VAs and constitute potential ablation targets. However, voltage mapping, as it is currently performed, is time-consuming, requiring a manual analysis of all EGMs to detect SCCs, and its accuracy is limited by electric far-field. We sought to evaluate an algorithm that automatically identifies EGM-DC, classifies mapping points, and creates new voltage maps, named "Slow Conducting Channel Maps" (SCC-Maps). METHODS: Retrospective analysis of electroanatomic maps (EAM) from 20 patients (10 ischemic, 10 with arrhythmogenic right ventricular dysplasia/cardiomyopathy) was performed. EAM voltage maps were acquired during sinus rhythm and used for ablation. Preprocedural contrast-enhanced cardiac magnetic resonance (Ce-CMR) imaging was available for the ischemic population. Three mapping modalities were analysed: (i) EAM voltage maps using standard (EAM standard) or manual (EAM screening) thresholds for defining core and border zones; (ii) SCC-Maps derived from the use of the novel SCC-Mapping algorithm that automatically identify EGM-DCs measuring the voltage of the local component; and (iii) Ce-CMR maps (when available). The ability of each mapping modality in identifying SCCs and their agreement was evaluated. RESULTS: SCC-Maps and EAM screening identified a greater number of SCC entrances than EAM standard (3.45 ± 1.61 and 2.95 ± 2.31, resp., vs. 1.05 ± 1.10; p < 0.01). SCC-Maps and EAM screening highly correlate with Ce-CMR maps in the ischemic population when compared to EAM standard (Lin's correlation = 0.628 and 0.679, resp., vs. 0.212, p < 0.01). CONCLUSION: The SCC-Mapping algorithm allows an operator-independent analysis of EGM signals showing better identification of the arrhythmogenic substrate characteristics when compared to standard voltage EAM.

Catheter ablation of arrhythmogenic right ventricular cardiomyopathy ventricular tachycardia: 18-year experience in 284 patients.

AIMS: The study aims to describe the long-term outcome of radiofrequency catheter ablation for ventricular tachycardia (VT) in a large cohort arrhythmogenic right ventricular cardiomyopathy (ARVC) patients. METHODS AND RESULTS: Radiofrequency catheter ablation was performed in 284 ARVC patients due to VT between July 2000 and January 2019. An endocardial approach was used initially, with epicardial ablation procedures reserved for those patients who failed an endocardial ablation. Activation, entrainment, pace and substrate mapping strategies were used with regional ablation applied. A total of 393 ablation procedures were performed including endocardial approach only (n = 377) and endo and epicardial combined (n = 16). Right ventricular basal free wall was accounted as the primary substrate of VT in 258 (65.6%) patients. There were 81 patients underwent redo ablation procedure (second time = 81; ≥3 times = 28). New targets were observed in 68.8% of redo procedures. There were 171 VT recurrences and 19 deaths occurred during the follow-up. Ventricular tachycardia-free survival rate of the first, second, and last ablation procedure was 56.7%, 73.2%, and 78.1%, respectively. Multivariate analysis showed ≥3 induced VTs in the procedure was correlated with rehospitalized VT recurrence [hazard ratio (HR) 1.467, 95% confidence interval (CI) 1.052-2.046; P = 0.024]. For all-cause mortality, rehospitalized VT and ≥3 induced VTs were the independent risk factors (HR 2.954, 95% CI 1.8068.038; P = 0.034; HR 3.189, 95% CI 1.073-9.482; P = 0.037). CONCLUSION: Endocardial ablation is effective to ARVC VT though it may require repeated procedures. Induced multiple VTs was correlated with worse outcomes.

A novel genotype-based clinicopathology classification of arrhythmogenic cardiomyopathy provides novel insights into disease progression.

AIMS: Arrhythmogenic cardiomyopathy (AC) shows large heterogeneity in its clinical, genetic, and pathological presentation. This study aims to provide a comprehensive atlas of end-stage AC and illustrate the relationships among clinical characteristics, genotype, and pathological profiles of patients with this disease. METHODS AND RESULTS: We collected 60 explanted AC hearts and performed standard pathology examinations. The clinical characteristics of patients, their genotype and cardiac magnetic resonance imaging findings were assessed along with pathological characteristics. Masson staining of six representative sections of each heart were performed. Digital pathology combined with image segmentation was developed to calculate distribution of myocardium, fibrosis, and adipose tissue. An unsupervised clustering based on fibrofatty distribution containing four subtypes was constructed. Patients in Cluster 1 mainly carried desmosomal mutations (except for desmoplakin) and were subjected to transplantation at early age; this group was consistent with classical 'desmosomal cardiomyopathy'. Cluster 2 mostly had non-desmosomal mutations and showed regional fibrofatty replacement in right ventricle. Patients in Cluster 3 showed parallel progression, and included patients with desmoplakin mutations. Cluster 4 is typical left-dominant AC, although the genetic background of these patients is not yet clear. Multivariate regression analysis revealed precordial QRS voltage as an independent indicator of the residual myocardium of right ventricle, which was validated in predicting death and transplant events in the validation cohort (n = 92). CONCLUSION: This study provides a novel classification of AC with distinct genetic backgrounds indicating different potential pathogenesis. Cluster 1 is distinct in genotype and clinicopathology and can be defined as 'desmosomal cardiomyopathy'. Precordial QRS amplitude is an independent indicator reflecting the right ventricular remodelling, which may be able to predict transplant/death events for AC patients.

A case of arrhythmogenic right ventricular cardiomyopathy with right ventricle thrombus: A case report.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare inherited cardiomyopathy characterised by right ventricular dysfunction, ventricular arrhythmias and increased risk of sudden cardiac death. Due to the replacement of myocardium with fibro-fatty and fibrous tissue, patients with ARVC are prone to develop ventricular tachycardia. Histologically, it is often reported as the 'triangle of dysplasia' involving the inflow tract, outflow tract and apex of the right ventricle.2 We describe a 20-years-old patient who collapsed during a futsal match and was subsequently diagnosed to have ARVC with a right ventricular thrombus from cardiac magnetic resonance imaging.

Long-term support by left ventricular assist device for arrhythmogenic right ventricular cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a heart muscle disorder characterized by right ventricular enlargement, right heart failure (HF), and ventricular arrhythmias which lead to sudden death especially in young adults. Current recommendations for management of patients with ARVC are antiarrhythmic medications, catheter ablation, and implantable cardioverter defibrillator therapy to prevent sudden cardiac death. However, despite these treatments, few patients suffer from recurrent ventricular arrhythmias or HF unresponsive to conventional management. Heart transplantation (HTx) is a preferred treatment for these cases, but because of a persistent donor heart shortage in Japan, ventricular assist device (VAD) support has become an important option for a management of the end-stage ARVC. Previous articles reported 4 cases of a successful management by left ventricular assist device (LVAD), but the longest interval of LVAD support was only 333 days. We present 3 cases of ARVC patients who were successfully managed by LVAD implantation for more than a year. These 3 cases are unconventional examples of ARVC patients, considering the nature of the disease. The novelty of these cases should be taken in the context of the extremely long waiting period for HTx in Japan.

Effect of Exercise on Outcome after Ventricular Tachycardia Ablation in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy.

Competitive sports and intensive exercise are associated with adverse outcomes in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). This study aimed to assess the role of exercise on long-term results of radiofrequency catheter ablation (RFCA) therapy of ventricular tachycardia (VT) in patients with ARVD/C. Exercise participation was evaluated by telephone or in-person interviews in patients from our ARVD/C registry with previous VT ablation (38 patients, 26 males, age 52.6±14.1years). Of 38 patients, 30 were involved in sports activities before RFCA. Only the minority of our patient population (21.1%) had a sedentary lifestyle before RFCA; 42.1 and 36.8% reported recreational or competitive sports, respectively. During the follow-up period of 52.5±31.4 months, 23 of the total 38 patients with previous RFCA (60.5%) remained free from VT recurrence. In univariate and binary logistic regression analysis, only advanced age was significantly associated with VT recurrence, with a hazard ratio of 1.15, and 95% confidence interval 1.05-1.26 (p=0.004). The results of our observational study indicate that recreational sports do not impair long-term results after RFCA treatment compared with a sedentary lifestyle. Furthermore, the dynamic component of recreational exercise did not affect the outcome of VT ablation in our patient population. Recreational exercise at low to moderate intensity is not associated with an increased risk for VT recurrence after catheter ablation in patients with ARVD/C.

Circulating microRNAs in arrhythmogenic right ventricular cardiomyopathy with ventricular arrhythmia.

Aims: MicroRNAs (miRNAs) have been implicated in cardiac diseases. This study aimed to characterize the circulating miRNAs in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) and correlate the miRNAs with the clinical outcomes of ARVC. Methods and results: This study included 62 patients with ventricular arrhythmia (VA): 28 patients (45%) had definite ARVC, 11 (18%) had borderline or possible ARVC, and 23 (37%) had idiopathic ventricular tachycardia (VT). In addition, 33 age- and sex-matched healthy subjects were enrolled as normal control subjects. The expression of selected miRNAs was analysed in all study subjects. The clinical outcomes of patients with definite ARVC after catheter ablation were further investigated. On the basis of the miRNA polymerase chain reaction array, we selected 11 miRNAs for analysis of their expression in the plasma of all subjects. Definite ARVC patients had significantly higher expression of circulating miR-144-3p, 145-5p, 185-5p, and 494 than the three other groups. Out of 25 definite ARVC patients who underwent radiofrequency catheter ablation, recurrent VA occurred in 8 patients (32%) during the follow-up period (45 ± 20 months). Definite ARVC patients with recurrent VA had a higher level of circulating miR-494 than did those without recurrence. Receiver operating characteristic analysis showed miR-494 to be a predictive factor of recurrent VA (area under the curve: 0.832). Conclusion: Plasma levels of miR-144-3p, 145-5p, 185-5p, and 494 were significantly elevated in definite ARVC patients with VA. An increased plasma level of miR-494 was associated with the recurrence of VA after ablation in definite ARVC patients.

Catheter Ablation in the Right Ventricular Outflow Tract Associated With Occlusion of Left Anterior Descending Coronary Artery.

Major vessel injury during right ventricular outflow tract ablation is not something widely recognized, and routine evaluation of the left anterior descending (LAD) artery location in relation to the septal right ventricle is not routinely performed. In the present article, we report a case of acute LAD occlusion after right ventricular outflow tract ablation and then illustrate the intimately close relationship of the LAD artery to the anterior septal site of the RVOT (approximately 2-3 cm under the pulmonic valve), using a combination of intracardiac echocardiography and 3-dimensional electroanatomical mapping recorded during a second case, in order to specifically point to the area at risk.

Survival After Heart Transplantation in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy.

BACKGROUND: Outcomes of arrhythmogenic right ventricular cardiomyopathy (ARVC) patients after heart transplantation have not been well studied. Diagnostic criteria were established in 1994 and subsequently revised in 2010. We sought to better characterize this population in a national cohort. METHODS: A total of 35,138 heart transplant-only recipients were identified from the United Network for Organ Sharing (UNOS) Thoracic Registry (1994-2011); 73 had ARVC. The non-ARVC group included ischemic cardiomyopathy, restrictive cardiomyopathy, dilated cardiomyopathy, hypertrophic cardiomyopathy, and other. Survival was censored at 12 years. Multivariate Cox proportional hazard regression analysis was adjusted for age, sex, DM, race, ischemia time, dialysis, life support, wait time, and HLA mismatch. RESULTS: There were 73 ARVC and 35,065 non-ARVC patients. The ARVC cohort was associated with less ventricular assist device use (P = .001) and significantly decreased pulmonary arterial and capillary wedge pressures (P < .001). Survivals at 1, 5, and 10 years were, respectively, ARVC 87%, 81%, and 77%, and non-ARVC 87%, 72%, and 53% (log rank P = .07). The ARVC unadjusted hazard ratio for all-cause mortality was 0.59 (95% confidence interval [CI] 0.34-1.04; P = .073). Multivariate analysis yielded a hazard ratio of 0.68 (95% CI 0.35-1.30; P = .25). ARVC survival was similar to restrictive, hypertrophic, and dilated cardiomyopathies and significantly better than ischemic cardiomyopathy. CONCLUSIONS: This is the largest reported series of ARVC after heart transplantation, of which 11% were pediatric. Survival was similar to the non-ARVC cohort, with improved survival over ischemic and restrictive etiologies.

Safety, long-term outcomes and predictors of recurrence after first-line combined endoepicardial ventricular tachycardia substrate ablation in arrhythmogenic cardiomyopathy. Impact of arrhythmic substrate distribution pattern. A prospective multicentre study.

BACKGROUND: First-line endoepicardial ventricular tachycardia (VT) ablation has been proposed for patients with arrhythmogenic cardiomyopathy (AC). This study reports procedural safety, outcomes, and predictors of recurrence. METHODS AND RESULTS: Forty-one consecutive patients [12 with left ventricle (LV) involvement, 7 left-dominant] underwent first-line endoepicardial VT substrate ablation. Standard bipolar and unipolar thresholds were used to define low-voltage areas (LVA). Arrhythmogenic substrate area (ASA) was defined as the area containing electrograms with delayed components. Implantable cardioverter defibrillator interrogations were evaluated for VT recurrence. Epicardial LVA was larger in all cases (102.5 ± 78.6 vs. 19.3 ± 24.4 cm2; P< 0.001). Consistent with an epicardium-to-endocardium arrhythmogenic substrate progression pattern, epicardial ASA (epi-ASA) was negatively correlated with bipolar endocardial LVA (r = -0.368; P= 0.035) and with endocardial bipolar/unipolar-LVA (Bi/Uni-LVA) ratio (r= -0.38; P= 0.037). A Bi/Uni-LVA ratio >0.23 predicted an epi-ASA ≤10 cm2 (100% sensitivity, 84% specificity). Patients showing an epi-ASA < 10 cm2 required less epicardial (8.4 ± 5.8 vs. 25.3 ± 16; P= 0.045) and more endocardial (16.5 ± 8.6 vs. 7.5 ± 8.2; P= 0.047) radiofrequency applications. One patient with epi-ASA < 10 cm2 died of cardiac tamponade after epicardial puncture. Acute success (no VT inducibility after procedure) was achieved in 36 patients (90%). After 32.2 ± 21.8 months, 11 (26.8%) patients had VT recurrences. Left-dominant AC was associated with an increased risk of recurrence (HR = 3.41 [1.1-11.2], P= 0.044; log-rank P= 0.021). CONCLUSION: First-line endoepicardial VT substrate ablation achieves good long-term results in AC. Left-dominant AC is associated with an increased risk of recurrence. The Bi/Uni-LVA ratio identifies patients with limited epicardial arrhythmogenic substrate in whom the indication of epicardial approach should be more cautiously assessed.

Radiofrequency Ablation in Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC).

PURPOSE OF REVIEW: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a heritable form of cardiomyopathy, typically with autosomal dominant transmission, shown to be a defect in the cardiac desmosomes, with distinct regional and histopathological features. Clinically, this can ultimately result in bi-ventricular failure and/or malignant ventricular tachycardia (VT) via reentrant circuits created by patchy scar formation. We sought to review the current treatment for ventricular arrhythmias in the setting of ARVC, with particular attention to radiofrequency (RF) ablation and its varied techniques, along with potential therapies in the ablation spectrum. RECENT FINDINGS: There is underwhelming data on the effectiveness of medical therapy for ARVC-related VT, including beta-blockers and antiarrhythmic medication. Primary and secondary prophylactic implantable-cardioverter defibrillator (ICD) implantation in higher-risk patients is recommended. More recently, RF ablation has been used for ARVC-related VT. Endocardial VT ablation in this setting can produce acute success, though recurrence rate is quite high, which may be explained by the more epicardial and patchy nature of the disease. Combined endocardial-epicardial ablation has since been shown to be feasible, safe, and with significantly better acute and long-term success, particularly when combined with scar dechanneling or homogenization of the scar. However, recurrence rates are not insignificant, and ablation does not eliminate the need for ICD placement. Medical therapy for ARVC-related VT is suboptimal. RF ablation techniques including endocardial and epicardial approaches appear to have the highest success rates for ARVC-related VT. Catheter ablation of VT in ARVC patients should be considered a potentially effective strategy for eliminating frequent VT episodes and ICD shocks rather than a curative therapeutic approach, until long-term efficacy has been consistently documented. Research into the optimal mapping and ablation techniques are promising and ongoing.

Dilemma in clinical diagnosis of right ventricular masses.

Detection of an intracardiac mass always represents a clinical challenge. We present a 61-year-old female patient with symptoms of New York Heart Association class III. Two-dimensional transthoracic echocardiography revealed a hypoechogenic mass in the cavity of the dilated right ventricle (RV). Cardiac MRI described a pathologic structure of the RV free wall with pedunculated tumor in its cavity. Three months later, on a repeated echocardiography, there were three individual masses. The patient underwent surgery and the pathohistologic report demonstrated thrombotic masses. During the postoperative period, after reviewing all medical records, the conclusion was arrhythmogenic RV cardiomyopathy. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:362-369, 2017.