Ebstein Anomaly

Atrial Flutters in Adults with Congenital Heart Disease

The macroreentrant atrial tachycardia is very frequent in the adults with congenital heart disease. The impact of the arrhythmias on this type of patients is related to several factors: the anatomy and physiopathology of the specific congenital heart disease (CHD), the sequelae of the corrective surgery or surgical palliation, the presence of residual lesions (shunt, regurgitation), and the age and the clinical status of the patient and the comorbidities. In turn, the mechanism of the MAT depends on the peculiar features of the conduction's system in the CHD and native and acquired (post-surgery) substrates.

Visualization of an Accessory Pathway by 3D High-Density Mapping: A Case of Ebstein Anomaly With Atrioventricular Re-entrant Tachycardia

Radiofrequency catheter ablation (RFCA) is the primary choice for treating patients with an accessory pathway and atrioventricular re-entrant tachycardia. However, using RFCA to treat a right-sided accessory pathway in a patient with Ebstein anomaly can be difficult owing to challenges in locating the electrophysiological atrioventricular groove. We report a case of atrioventricular re-entrant tachycardia in a patient with Ebstein anomaly and a right-sided accessory pathway that was successfully treated using RFCA and 3-dimensional (3D) high-density mapping. RFCA and 3D mapping may be useful in the management of such cases and may aid in improving prognoses of patients.

Accessory pathway ablation in Ebstein anomaly: A challenging substrate

BACKGROUND

Catheter ablation of accessory pathways (APs) in Ebstein anomaly (EA) has been associated with a high recurrence risk.

OBJECTIVE

The purpose of this study was to compare outcomes of AP ablation in EA in an early (1990-2004) vs a recent (2005-2019) era and identify variables associated with recurrence.

METHODS

A retrospective review of all catheter ablations for supraventricular tachycardia in EA at our institution was performed.

RESULTS

We identified 76 patients with median (25th-75th quartiles) age 9 (2.6-13.3) years. Of these patients, 52 had AP alone, 12 had atrial flutter, 3 had atrioventricular nodal reentrant tachycardia, and 9 had AP plus at least 1 additional arrhythmia. Of the 61 patients with APs, a total of 78 separate APs were identified: 40 right-sided, 37 septal, and 1 left-sided. Acute success for AP first procedure was 89% and did not differ between early and recent eras (89% vs 88%; P = .48). However, 19 patients (31%) required repeat procedures (average 1.4 per patient) due to AP recurrence or ablation failure at first attempt. In comparison to early era, recent era ablations had significantly lower recurrence rates at 1 year (62% vs 19%; P = .005). At median follow-up of 2.5 (0.2-7) years, ultimate AP elimination after all procedures was 93%. Younger age at time of electrophysiological study (<2 vs 12-47 years: hazard ratio [HR] 7.3; P = .003) and ablation era (early era vs recent era: HR 3.65; P = .009) predicted recurrence.

CONCLUSION

Outcomes for AP ablation in patients with EA have improved, but there is still a relatedly high recurrence risk requiring repeat procedures.

Management of tachyarrhythmias in pregnancy - A review

The most common arrhythmias detected during pregnancy include sinus tachycardia, sinus bradycardia, and sinus arrhythmia, identified in 0.1% of pregnancies. Isolated premature atrial or ventricular arrhythmias are observed in 0.03% of pregnancies. Arrhythmias may become more frequent during pregnancy or may manifest for the first time.

Differential diagnosis of arrhythmogenic cardiomyopathy: phenocopies versus disease variants

Arrhythmogenic cardiomyopathy (ACM) is a genetic heart muscle disease caused by mutations of desmosomal genes in about 50% of patients. Affected patients may have defective non-desmosomal genes. The ACM phenotype may occur in other genetic cardiomyopathies, cardio-cutaneous syndromes or neuromuscular disorders. A sizeable proportion of patients have non-genetic diseases with clinical features resembling ACM (phenocopies). The identification of biventricular and left-dominant phenotypic variants has made differential diagnosis more difficult because of the broader spectrum of phenocopies which requires a detailed clinical study with appropriate evaluation of most prominent and discriminatory disease features. Conditions that enter into differential diagnosis of ACM include heart muscle diseases affecting the right ventricle, the left ventricle, or both. To confirm a conclusive diagnosis of ACM, these differential possibilities need to be reasonably excluded by an accurate and targeted clinical evaluation. This article reviews the clinical and imaging features of major phenocopies of ACM and provides indications for differential diagnosis. The recent etiologic classification of Arrhythmogenic Cardiomyopathies, whose common denominator is the distinctive phenotype characterized by a hypokinetic and non-dilated ventricle with a large amount of myocardial fibrosis underlying its propensity to generate ventricular arrhythmias is also addressed.

Ebstein Anomaly in the Adult Patient

Ebstein anomaly is a congenital malformation involving primarily the tricuspid valve, with failure of delamination from the underlying myocardium and right ventricular myopathy. Echocardiography is diagnostic in most patients and demonstrates apical displacement of the septal leaflet and variable tethering of leaflet tissue to the right ventricular myocardium. Operative intervention is considered for exertional symptoms, progressive right ventricular enlargement, or right ventricular dysfunction. Tricuspid valve cone repair is the preferred surgical approach. Tricuspid valve replacement and bidirectional cavopulmonary shunt also are considered in patients with advanced disease. Pregnancy generally is well tolerated. Patients with Ebstein anomaly require lifelong follow-up.

Challenges in Ablation of Complex Congenital Heart Disease

The field of congenital cardiac electrophysiology is growing rapidly due to the rapid growth in the population of survivors of childhood critical congenital heart disease surgery. Chronic arrhythmias pose one of the biggest challenges in this patient population, and catheter ablation, despite its challenges, is still the most desirable and acceptable approach when successful. Clinicians who propose catheter ablation in such patients need to understand the congenital anatomy, should carefully review the details of all prior cardiac surgery, and should be prepared to deal with the various challenges posed by lack of normal cardiac access and the possibility of poor hemodynamics. Still, experienced laboratories can achieve excellent results in this difficult patient population.

A Young Woman With Recurrent Palpitations: A Case of Ebstein Anomaly With Mahaim Fiber Tachycardia

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EA is a distinct entity on echocardiography.

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Accessory pathways are commonly seen with EA.

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Mahaim fiber tachycardia is a rare accessory pathway–mediated tachycardia.

Right Heart-Pulmonary Circulation Unit in Congenital Heart Diseases

The right ventricle plays a major role in congenital heart disease. This article describes the right ventricular mechanics in some selected congenital heart diseases affecting the right ventricle in different ways: tetralogy of Fallot, Ebstein anomaly, and the systemic right ventricle.

Ebstein Anomaly and Sudden Childhood Death

A 13-year-old girl is reported who died suddenly and unexpectedly in her sleep from previously undiagnosed Ebstein anomaly. At autopsy, there was dilatation of the right atrium with marked dilatation of the right auricle and apical displacement of the tricuspid valve into the right ventricular cavity with atrialization of the upper portion of the right ventricle. There were also prominent dysplastic changes in both the septal and posterior leaflets of the tricuspid valve with thickening of the valve and fusion of leaflets to the wall of the ventricle. Histology of the myocardium showed focal, minor microscopic areas of interstitial fibrosis with marked fibrous dysplasia and thickening of the tricuspid valve. Lethal arrhythmias occur in this condition because of the geographical relationship of the conduction system to the abnormal anatomical structures. As adolescents who died suddenly are often minimally symptomatic, cases will rarely present de novo to forensic autopsy.