Long-Term Outcomes of Radio-Frequency Catheter Ablation on Ventricular Tachycardias Due to Arrhythmogenic Right Ventricular Cardiomyopathy: A Single Center Experience

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.

Cardiomyopathies in China: A 2018-2019 state-of-the-art review

Cardiomyopathies are diseases of the cardiac muscle and are often characterized by ventricular dilation, hypertrophy, and cardiac arrhythmia. Patients with cardiomyopathies often experience sudden death and cardiac failure and require cardiac transplantation during the course of disease progression. Early diagnosis, differential diagnosis, and genetic consultation depend on imaging techniques, genetic testing, and new emerging diagnostic tools such as serum biomarkers. The molecular genetics of cardiomyopathies has been widely studied recently. The discovery of mechanisms underlying heterogeneity and overlapping of the phenotypes of cardiomyopathies has revealed the existence of disease modifiers, and this has led to the emergence of novel disease-modifying therapy. This 2018-2019 state-of-the-art review outlines the pathogenesis, diagnosis, and treatment of cardiomyopathies in China.

Ablation strategies for arrhythmogenic right ventricular cardiomyopathy: a systematic review and meta-analysis

Background

Catheter ablation for ventricular tachycardia (VT) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) has significantly evolved over the past decade. However, different ablation strategies showed inconsistency in acute and long-term outcomes.

Methods

We searched the databases of Medline, Embase and Cochrane Library through October 17, 2019 for studies describing the clinical outcomes of VT ablation in ARVC. Data including VT recurrence, all-cause mortality, acute procedural efficacy and major procedural complications were extracted. A meta-analysis with trial sequential analysis was further performed in comparative studies of endo-epicardial versus endocardial-only ablation.

Results

A total of 24 studies with 717 participants were enrolled. The literatures of epicardial ablation were mainly published after 2010 with total ICD implantation of 73.7%, acute efficacy of 89.8%, major complication of 5.2%, follow-up of 28.9 months, VT freedom of 75.3%, all-cause mortality of 1.1% and heart transplantation of 0.6%. Meta-analysis of 10 comparative studies revealed that compared with endocardial-only approach, epicardial ablation significantly decreased VT recurrence (OR: 0.50; 95% CI: 0.30-0.85; P = 0.010), but somehow increased major procedural complications (OR: 4.64; 95% CI: 1.28-16.92; P= 0.02), with not evident improvement of acute efficacy (OR: 2.74; 95% CI: 0.98-7.65; P = 0.051) or all-cause mortality (OR: 0.87; 95% CI: 0.09-8.31; P = 0.90).

Conclusion

Catheter ablation for VT in ARVC is feasible and effective. Epicardial ablation is associated with better long-term VT freedom, but with more major complications and unremarkable survival or acute efficacy benefit.

Epicardial Ablation of Ventricular Tachycardia in Arrhythmogenic Right Ventricular Cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart muscle disease characterized by progressive fibrofatty replacement of the myocardium, right ventricular enlargement, and malignant ventricular arrhythmias. Ventricular tachycardia (VT) may be seen in all stages of the disease and is associated with sudden cardiac death. In patients who failed anti-arrhythmic medical therapy, catheter ablation has become an attractive therapeutic option to reduce VT burden and implantable cardioverter-defibrillator interventions. In this article, the authors aim to address the overall concepts of epicardial catheter ablation in ARVC, focusing on substrate characterization and ablation strategies.

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.

A novel percutaneous stabilizing sheath for minimal invasive epicardial echocardiography and ablation

PURPOSE

Epicardial ablation and mapping are critical adjuncts to the electrophysiologist's approach to arrhythmias; however, ablation within the epicardial space requires the avoidance of coronary arteries (CA). We aimed to evaluate the feasibility and performance of a novel-stabilizing ablation sheath housing an intracardiac echocardiography (ICE) catheter to (1) obtain Epicardial Echocardiography (EE) images, (2) visualize CAs, and (3) enable targeted delivery of radiofrequency energy away from visualized CAs.

METHODS

We designed a sheath that could enclose a regular ICE catheter. This sheath has flanges and a balloon, with three interspersed windows surrounded by an electrode. In an acute canine model (N = 6), the sheath was manipulated within the pericardial space to visualize cardiac structures and CAs. Visualization of CAs was confirmed with angiography. Ablation was then performed through the window either proximal or distal to the CA.

RESULTS

The novel sheath was successfully deployed in six canines, with no acute procedural complications. Images with an excellent spatial resolution of cardiac structures were obtained including the right ventricular outflow tract; aortic, pulmonary, and mitral valves; and left atrial appendage. CAs were successfully visualized, and ablation from a sheath window either proximal or distal to the CA did not produce angiographic or histopathological evidence of CA damage despite evidence of acute injury to the adjacent ablated myocardium.

CONCLUSIONS

This novel percutaneous stabilizing sheath was able to successfully obtain high-quality EE images as well as provide a non-fluoroscopic intra-procedural means to visualize CAs. Use of this sheath enabled successful delivery of energy to avoided CA damage.

Case report of familial sudden cardiac death caused by a DSG2 p.F531C mutation as genetic background when carrying with heterozygous KCNE5 p.D92E/E93X mutation

Background

Sudden cardiac death (SCD) induced by malignant ventricular tachycardia (MVT) among young adults with right ventricular cardiomyopathy/dysplasia (ARVC/D) is a devastating event. Parts of ARVC/D patients have a mutation in genes encoding components of cardiac desmosomes, such as desmoglein-2 (DSG2), plakophilin-2 and desmoplakin.

Case presentation

Here we report a potentially pathogenic mutation in the DSG2 gene, which was identified in a family with ARVC/D using Whole Exome Sequencing (WES) and Sanger Sequencing. In all, Patient III:1 with ARVC/D carried the compound heterozygous mutations of DSG2 p.F531C and KCNE5 p.D92E/E93X, which were both inherited from her mother (II:2), who died of SCD. Carriers of DSG2p.F531C showed various phenotypes, such as ARVC/D, SCD, MVT and dilated cardiomyopathy. For III:1, there were significant low-voltage regions in the inferior-apical, inferior-lateral wall of the right ventricular epicardium and outflow tracts of the right ventricle. Under the guidance of a three-dimensional mapping system, MVT was successfully ablated with an epicardial–endocardial approach targeting for late, double or fragmental potentials after implantable cardioverter-defibrillator (ICD) electrical storms. No VT recurrence was observed during the one year of follow-up.

Conclusions

When coexisting with heterozygous KCNE5 p.D92E/E93X, heterozygous DSG2 p.F531C as a genetic background was found to predispose to ARVC/D, SCD and MVT, which were successfully ablated using an epicardial–endocardial approach.

Electronic supplementary material

The online version of this article (10.1186/s12881-018-0580-2) contains supplementary material, which is available to authorized users.

Association of regional epicardial right ventricular electrogram voltage amplitude and late gadolinium enhancement distribution on cardiac magnetic resonance in patients with arrhythmogenic right ventricular cardiomyopathy: Implications for ventricular tachycardia ablation

BACKGROUND

Criteria for identification of anatomic ventricular tachycardia substrates in arrhythmogenic right ventricular cardiomyopathy (ARVC) on late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) are unclear.

OBJECTIVE

The purpose of this study was to define (1) the association of regional right ventricular (RV) epicardial voltage amplitude with the distribution of LGE; and (2) appropriate image signal intensity (SI) thresholds for ventricular tachycardia substrate identification in ARVC.

METHODS

Preprocedural LGE-CMR and epicardial electrogram mapping were performed in 10 ARVC patients. The locations of epicardial electrogram map points, obtained during sinus rhythm with intrinsic conduction or RV pacing, were retrospectively registered to the corresponding LGE image regions. Standardized SI z-scores (standard deviation distance from the mean) were calculated for each 10-mm region surrounding map points.

RESULTS

In patient-clustered, generalized estimating equations models that included 3205 epicardial electroanatomic points and corresponding SI measures, bipolar (-1.43 mV/z-score; P <.001) and unipolar voltage amplitude (-1.22 mV/z-score; P <.001) were associated with regional SI z-scores. In contrast to the QRS-late potential (LP) interval (P = .362), the LP activation index, defined as electrogram duration divided by QRS-LP, was associated with regional SI z-scores (P <.001). SI z-score thresholds >0.05 (95% confidence interval -0.05 to 0.15) and <-0.16 (95% confidence interval -0.26 to 0.06) corresponded to bipolar voltage measures <0.5 and >1.0 mV, respectively.

CONCLUSION

Increased RV gadolinium uptake is associated with lower epicardial bipolar and unipolar electrogram voltage amplitude. Standardized LGE-CMR SI z-scores may augment preprocedural planning for identification of low-voltage zones and abnormal myocardium in ARVC.

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) in clinical practice

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is an inherited myocardial disease characterized by fibro-fatty replacement of the right ventricular myocardium, and associated with paroxysmal ventricular arrhythmias and sudden cardiac death (SCD). It is currently the second most common cause of SCD after hypertrophic cardiomyopathy in young people <35 years of age, causing up to 20% of deaths in this patient population. This condition has a male preponderance and is more commonly found in individuals of Italian and Greek descent. To date, there is no single diagnostic test for ARVC/D and the diagnosis is made based on clinical, electrocardiographic, and radiological findings according to the Revised 2010 Task Force Criteria. In this review, we will discuss the mainstay treatment which includes pharmacotherapy, implantable cardioverter-defibrillator insertion for abortion of sudden cardiac death, and in the advanced stages of the disease cardiac transplantation.

Catheter Ablation of Ventricular Tachycardia in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is predominantly an inherited cardiomyopathy with typical histopathological characteristics of fibro-fatty infiltration mainly involving the right ventricular (RV) inflow tract, RV outflow tract, and RV apex in the majority of patients. The above pathologic evolution frequently brings patients with ARVD/C to medical attention owing to the manifestation of syncope, sudden cardiac death (SCD), ventricular arrhythmogenesis, or heart failure. To prevent future or recurrent SCD, an implantable cardiac defibrillator (ICD) is highly desirable in patients with ARVD/C who had experienced unexplained syncope, hemodynamically intolerable ventricular tachycardia (VT), ventricular fibrillation, and/or aborted SCD. Notably, the management of frequent ventricular tachyarrhythmias in ARVD/C is challenging, and the use of antiarrhythmic drugs could be unsatisfactory or limited by the unfavorable side effects. Therefore, radiofrequency catheter ablation (RFCA) has been implemented to treat the drug-refractory VT in ARVD/C for decades. However, the initial understanding of the link between fibro-fatty pathogenesis and ventricular arrhythmogenesis in ARVD/C is scarce, the efficacy and prognosis of endocardial RFCA alone were limited and disappointing. The electrophysiologists had broken through this frontier after better illustration of epicardial substrates and broadly application of epicardial approaches in ARVD/C. In recent works of literature, the application of epicardial ablation also successfully results in higher procedural success and decreases VT recurrences in patients with ARVD/C who are refractory to the endocardial approach during long-term follow-up. In this article, we review the important evolution on the delineation of arrhythmogenic substrates, ablation strategies, and ablation outcome of VT in patients with ARVD/C.