Clinical aspects of myocardial fibrosis in adults with Ebstein's anomaly

Correlation between Epsilon Wave and Late Potentials in Arrhythmogenic Right Ventricular Cardiomyopathy-Do Late Potentials Define the Epsilon Wave?

Introduction: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic disorder characterised by progressive fibrosis predominantly of the right ventricular (RV) myocardium, resulting in life-threatening arrhythmias and heart failure. The diagnosis is challenging due to a wide spectrum of clinical symptoms. The important role of ECG was covered in the current diagnostic criteria. The role of the epsilon wave (EW) is still under discussion. Aim: The aim of the study was to examine a potential association between the EW and late ventricular potentials (LPs) in ARVC patients (pts). The correlation between RV dilatation or dysfunction and LPs/EW was also analysed. Methods: The ARVC group consisted of 81 pts (53 men, aged 20-78 years) fulfilling 2010 International Task Force Criteria. 12-lead ECG, LPs, Holter, and ECHO were performed in all pts. The presence of EW was analysed in ECG by 3 investigators. LPs were detected by signal-averaged ECG (SAECG). SAECG was considered positive for LPs when at least two of the three following criteria were met: (1) the filtered QRS duration (fQRS) ≥ 114 msec; (2) the duration of the final QRS fragment in which low-amplitude signals lower than 40 μV are recorded (LAS-40 > 38 msec); and (3) the root mean square amplitude of the last 40 milliseconds of the fQRS complex (RMS-40 < 20 μV). The results were compared with a reference group consisting of 53 patients with RV damage in the course of atrial septum defect (ASD) or Ebstein's Anomaly (EA). Results: In the ARVC group, a significant relationship was observed between the occurrence of EW and the presence of LPs. EW was more common in the LP+ than in the LP- patients (48.1% vs. 6.9%, p < 0001; OR 12.5; 95% CI [2.691-58.063]). In ARVC pts, RVOT > 36 mm, RVIT > 41 mm, and RV S' < 9 cm/s were observed significantly more often in the LPs+ than in the LPs- group (OR [95% CI]: 8.3 [2.9-1.5], 6.4 [2.2-19.0] and 3.6 [1.1-12.2], respectively). In the ARVC group, any of fQRS > 114 ms, LAS > 38 ms, and RMS < 20 μV were significantly more frequent in EW+ pts. In multivariate analysis, the independent factors of the EW were LAS-40 and RV S'. In the LPs- subgroup, RVOT > 36 mm was more frequent in ASD/EA than in ARVC (70.4% vs. 25%, p = 0.002). Similarly, in the LPs- subgroup, RVIT > 41 mm was encountered more frequently in ASD/EA than in ARVC (85.2% vs. 48.3%, p = 0.004). Conclusions: In ARVC, there is an association between EW and LPs, with both probably resulting from the same process of fibrofatty substitution of the RV myocardium. Although RV dilatation is common in ASD and EA, it does not correlate with LPs.

Unlocking the Potential: Angiotensin Receptor Neprilysin and Sodium Glucose Co-Transporter 2 Inhibitors for Right Ventricle Dysfunction in Heart Failure

This review article examines the mechanism of action of Angiotensin Receptor-Neprilysin Inhibitors (ARNIs) and Sodium-Glucose Co-Transporter 2 Inhibitors (SGLT2is) in managing chronic right ventricular (RV) dysfunction. Despite advancements in heart failure (HF) treatment, RV dysfunction remains a significant contributor to morbidity and mortality. This article explores the The article explores the impact of ARNIs and SGLT2is on RV function based on clinical and preclinical evidence, and the potential benefits of combined therapy. It highlights the need for further research to optimize patient outcomes and suggests that RV function should be considered in future clinical trials as part of risk stratification for HF therapies. This review underscores the importance of the early initiation of ARNIs and SGLT2is as per guideline-directed medical therapy for eligible HFrEF and HFpEF patients to improve co-existing RV dysfunction.

Ebstein's anomaly in children and adults: multidisciplinary insights into imaging and therapy

Although survival has significantly improved in the last four decades, the diagnosis of Ebstein's anomaly is still associated with a 20-fold increased risk of mortality, which generally drops after neonatal period and increases subtly thereafter. With increasing age of presentation, appropriate timing of intervention is challenged by a wide spectrum of disease and paucity of data on patient-tailored interventional strategies. The present review sought to shed light on the wide grey zone of post-neonatal Ebstein's manifestations, highlighting current gaps and achievements in knowledge for adequate risk assessment and appropriate therapeutic strategy.A 'wait-and-see' approach has been adopted in many circumstances, though its efficacy is now questioned by the awareness that Ebstein's anomaly is not a benign disease, even when asymptomatic. Moreover, older age at intervention showed a negative impact on post-surgical outcome.In order to tackle the extreme heterogeneity of Ebstein's anomaly, this review displays the multimodality imaging assessment necessary for a proper anatomical classification and the multidisciplinary approach needed for a comprehensive risk stratification and monitoring strategy. Currently available predictors of clinical outcome are summarised for both operated and unoperated patients, with the aim of supporting the decisional process on the choice of appropriate therapy and optimal timing for intervention.

CArdiac MagnEtic resonance assessment of bi-Atrial fibrosis in secundum atrial septal defects patients: CAMERA-ASD study

AIMS

Atrial septal defects (ASD) are associated with atrial arrhythmias, but the arrhythmia substrate in these patients is poorly defined. We hypothesized that bi-atrial fibrosis is present and that right atrial fibrosis is associated with atrial arrhythmias in ASD patients. We aimed to evaluate the extent of bi-atrial fibrosis in ASD patients and to investigate the relationships between bi-atrial fibrosis, atrial arrhythmias, shunt fraction, and age.

METHODS AND RESULTS

Patients with uncorrected secundum ASDs (n = 36; 50.4 ± 13.6 years) underwent cardiac magnetic resonance imaging with atrial late gadolinium enhancement. Comparison was made to non-congenital heart disease patients (n = 36; 60.3 ± 10.5 years) with paroxysmal atrial fibrillation (AF). Cardiac magnetic resonance parameters associated with atrial arrhythmias were identified and the relationship between bi-atrial structure, age, and shunt fraction studied. Bi-atrial fibrosis burden was greater in ASD patients than paroxysmal AF patients (20.7 ± 14% vs. 10.1 ± 8.6% and 14.8 ± 8.5% vs. 8.6 ± 6.1% for right and left atria respectively, P = 0.001 for both). In ASD patients, right atrial fibrosis burden was greater in those with than without atrial arrhythmias (33.4 ± 18.7% vs. 16.8 ± 10.3%, P = 0.034). On receiver operating characteristic analysis, a right atrial fibrosis burden of 32% had a 92% specificity and 71% sensitivity for predicting the presence of atrial arrhythmias. Neither age nor shunt fraction was associated with bi-atrial fibrosis burden.

CONCLUSION

Bi-atrial fibrosis burden is greater in ASD patients than non-congenital heart disease patients with paroxysmal AF. Right atrial fibrosis is associated with the presence of atrial arrhythmias in ASD patients. These findings highlight the importance of right atrial fibrosis to atrial arrhythmogenesis in ASD patients.

Multi-Modality Imaging of the Tricuspid Valve: From Tricuspid Valve Disease to Catheter-Based Interventions

Tricuspid valve disease represents a major health problem that affects a wide proportion of heart failure patients with a significant prognostic impact. In recent years an increasing number of minimally invasive and transcatheter treatments have been developed. The choice of the optimal transcatheter device therapy needs a careful patient selection and a dedicated anatomic assessment, mainly based on echocardiographic and computed tomography evaluation. Moreover, cardiac magnetic resonance has an established role in the functional assessment of right heart chambers with relevant prognostic implications. In this review we describe the role of multimodality imaging in the tricuspid valve disease assessment with an intervention-oriented perspective, from the pre-operative planning for different devices to the intraprocedural guide during transcatheter edge-to-edge repair.

Narrative review of Ebstein's anomaly beyond childhood: Imaging, surgery, and future perspectives

Ebstein's anomaly is a rare congenital heart disease with malformation of the tricuspid valve and myopathy of the right ventricle. The septal and inferior leaflets adhere to the endocardium due to failure of delamination. This leads to apical displacement of their hinge points with a shift of the functional tricuspid valve annulus towards the right ventricular outflow tract with a possibly restrictive orifice. Frequently, a coaptation gap yields tricuspid valve regurgitation and over time the "atrialized" portion of the right ventricle may dilate. The highly variable anatomy determines the clinical presentation ranging from asymptomatic to very severe with need for early operation. Echocardiography and magnetic resonance imaging are the most important diagnostic modalities to assess the tricuspid valve as well as ventricular morphology and function. While medical management of asymptomatic patients can be effective for many years, surgical intervention is indicated before development of significant right ventricular dilatation or dysfunction. Onset of symptoms and arrhythmias are further indications for surgery. Modified cone reconstruction of the tricuspid valve is the state-of-the-art approach yielding the best results for most patients. Alternative procedures for select cases include tricuspid valve replacement and bidirectional cavopulmonary shunt depending on patient age and other individual characteristics. Long-term survival after surgery is favorable but rehospitalization and reoperation remain significant issues. Further studies are warranted to identify the optimal surgical strategy and timing before adverse right ventricular remodeling occurs. It is this article's objective to provide a comprehensive review of current literature and an overview on the management of Ebstein's Anomaly. It focuses on imaging, cardiac surgery, and outcome. Additionally, a brief insight into arrhythmias and their management is given. The "future perspectives" summarize open questions and fields of future research.

Haemodynamic determinants of improved aerobic capacity after tricuspid valve surgery in Ebstein anomaly

BACKGROUND

Although tricuspid valve surgery improves functional capacity in patients with Ebstein anomaly, it is not always associated with improvement in aerobic capacity. The purpose of this study was to identify the determinants of improved aerobic capacity after tricuspid valve surgery in adults with Ebstein anomaly with severe tricuspid regurgitation.

METHODS

Retrospective study of patients with severe tricuspid regurgitation due to Ebstein anomaly that had tricuspid valve surgery at Mayo Clinic Rochester (2000-2019) and had preoperative and postoperative cardiopulmonary exercise tests and echocardiograms. The patients were divided into aerobic capacity(+) and aerobic capacity(-) groups depending on whether they had postoperative improvement in %-predicted peak oxygen consumption (VO2).

RESULTS

Of 76 patients with severe tricuspid regurgitation due to Ebstein anomaly, 28 (37%) and 48 (63%) were in aerobic capacity(+) and aerobic capacity(-) groups, respectively. The average improvement in peak VO2 was 2.1±1.4 mL/kg/min and -0.9±0.4 mL/kg/min in the in aerobic capacity(+) and aerobic capacity(-) groups, respectively. Although both groups had similar severity of residual tricuspid regurgitation, the aerobic capacity(+) group had more postoperative improvement in right atrial (RA) function, left atrial (LA) function and left ventricular preload and stroke volume. Of the preoperative variables analysed, RA reservoir strain (relative risk 1.12; 95% CI 1.06 to 1.18); LA reservoir strain (relative risk 1.09; 95% CI 1.04 to 1.14) and LV stroke volume index (OR 1.04; 95% CI 1.01 to 1.07) were predictors of postoperative improvement in peak VO2.

CONCLUSIONS

One-third of patients with severe tricuspid regurgitation due to Ebstein anomaly had postoperative improvement in aerobic capacity, and atrial function indices were the best predictors of postoperative improvement in aerobic capacity. These data provide new insight into the haemodynamic determinants of exercise capacity and lay the foundation for further studies to determine whether postoperative improvement in aerobic capacity translates to improved long-term survival, and whether timing of tricuspid valve surgery based on these echocardiographic indices will improve long-term outcomes.

Ebstein's Anomaly in Disguise: Follow the Cues and the Diagnosis Can Be Made

Ebstein's anomaly is a congenital defect, which is rarely present in adults with arrhythmias and right heart failure with tricuspid regurgitation. The diagnosis is made by non-invasive cardiac imaging with transthoracic echocardiography or cardiac magnetic resonance imaging. However, mild and atypical anatomical variants require a more specific investigation to make the diagnosis and differentiate it from other pathologies which have a similar presentation, including Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC). We present the case of a 66-year-old gentleman with a history of recurrent admissions due to decompensated heart failure exacerbations, now presenting with gradually worsening dyspnea. An echocardiogram was obtained, showing a thin-walled, dilated, and dysfunctional right ventricle (RV) with severe tricuspid regurgitation due to poor coaptation of the tricuspid leaflets. Although a very distinctive epsilon wave was seen on his electrocardiogram, highly suggestive of arrhythmogenic RV cardiomyopathy (ARVC), which would be enough to explain his presentation and initial echocardiogram; an off-axis plane of the tricuspid valve without any RV aneurysm or dilation of the RV outflow tract was incongruent with this diagnosis. Additional echocardiographic images were determinant to demonstrate both apical displacement and tethering of the septal tricuspid leaflet with an abnormally long anterior tricuspid leaflet, suggestive of Ebstein's anomaly. This diagnosis was confirmed with cardiac magnetic resonance imaging. Mild variants of Ebstein's anomaly, especially in the presence of confounding findings require focused imaging to ascertain the diagnosis. We review these non-traditional findings in trying to differentiate Ebstein's from ARVC.

Frontal QRS-T angle and left ventricular diastolic function assessed by ECG-gated SPECT in the absence of significant perfusion abnormality

The frontal QRS-T angle, defined as the angle between QRS and T-wave axes, has recently become an area of research interest. We tested the hypothesis that the frontal QRS-T angle is associated with left ventricular (LV) diastolic function in the absence of significant perfusion abnormality using ECG-gated SPECT. One hundred twenty eight patients with no significant perfusion abnormality and preserved LV ejection fraction were enrolled. The peak filling rate (PFR) and the one-third mean filling rate (1/3 MFR) were obtained as LV diastolic parameters on ECG-gated SPECT. There were 115 male and 13 female patients with a mean age of 70 ± 9 years. The PFR and 1/3 MFR were 2.1 ± 0.4/s and 1.2 ± 0.3/s, respectively. The frontal QRS-T angle was 33° ± 31°, ranging from 0° to 151°. There were significant associations of frontal QRS-T angle with PFR (r = - 0.29, p = 0.001) and 1/3 MFR (r = - 0.30, p < 0.001). Multivariate linear regression analysis showed that age (β = - 0.25, p = 0.003), heart rate (β = 0.26, p = 0.002), LV ejection fraction (β = 0.43, p < 0.001) and frontal QRS-T angle (β = - 0.16, p = 0.03) were significant factors associated with PFR. Also, heart rate (β = - 0.32, p < 0.001), LV mass index (β = - 0.19, p = 0.03), LV ejection fraction (β = 0.30, p < 0.001) and frontal QRS-T angle (β = - 0.26, p = 0.002) were significant factors associated with 1/3 MFR. Our data suggested that the frontal QRS-T angle was associated with LV diastolic function in the absence of significant perfusion abnormality.

Ebstein's Anomaly

Ebstein's anomaly is a malformation of the tricuspid valve with myopathy of the right ventricle (RV) that presents with variable anatomic and pathophysiologic characteristics, leading to equally variable clinical scenarios. Medical management and observation is often recommended for asymptomatic patients and may be successful for many years. Tricuspid valve repair is the goal of operative intervention; repair also typically includes RV plication, right atrial reduction, and atrial septal closure or subtotal closure. Postoperative functional assessments generally demonstrate an improvement or relative stability related to degree of RV enlargement, RV dysfunction, RV fractional area change, and tricuspid valve regurgitation.

ISL1 loss-of-function mutation contributes to congenital heart defects

Congenital heart defect (CHD) is the most common form of birth deformity and is responsible for substantial morbidity and mortality in humans. Increasing evidence has convincingly demonstrated that genetic defects play a pivotal role in the pathogenesis of CHD. However, CHD is a genetically heterogeneous disorder and the genetic basis underpinning CHD in the vast majority of cases remains elusive. This study was sought to identify the pathogenic mutation in the ISL1 gene contributing to CHD. A cohort of 210 unrelated patients with CHD and a total of 256 unrelated healthy individuals used as controls were registered. The coding exons and splicing boundaries of ISL1 were sequenced in all study subjects. The functional effect of an identified ISL1 mutation was evaluated using a dual-luciferase reporter assay system. A novel heterozygous ISL1 mutation, c.409G > T or p.E137X, was identified in an index patient with congenital patent ductus arteriosus and ventricular septal defect. Analysis of the proband's pedigree revealed that the mutation co-segregated with CHD, which was transmitted in the family in an autosomal dominant pattern with complete penetrance. The nonsense mutation was absent in 512 control chromosomes. Functional analysis unveiled that the mutant ISL1 protein failed to transactivate the promoter of MEF2C, alone or in synergy with TBX20. This study firstly implicates ISL1 loss-of-function mutation with CHD in humans, which provides novel insight into the molecular mechanism of CHD, implying potential implications for genetic counseling and individually tailored treatment of CHD patients.