Interventional Closure of Atrial Septal Defects in Adult Patients with Ebstein's Anomaly

A multidisciplinary approach to re-intervention in an Ebstein patient: a case report

Background

Ebstein's anomaly is a rare condition due to incomplete delamination of the tricuspid valve (TV) leaflets with downward displacement of the proximal leaflet attachments. It is associated with a smaller functional right ventricle (RV) and tricuspid regurgitation (TR) that is typically treated with TV replacement or repair. However, future re-intervention poses challenges. We describe a multidisciplinary team approach to re-intervention in a pacing-dependant Ebstein patient with severe bioprosthetic TV regurgitation.

Case summary

A 49-year-old female patient underwent bioprosthetic TV replacement for severe TR in Ebstein's. Post-operatively, she developed complete atrioventricular (AV) block necessitating the implantation of a permanent pacemaker which included a coronary sinus (CS) lead as the ventricular lead. Five years later, she presented with syncope due to a failing ventricular pacing lead, and a new RV lead was positioned across the TV bioprosthesis due to the lack of CS options. Two years later, she presented with breathlessness and lethargy with severe TR identified on transthoracic echocardiography. She successfully underwent a percutaneous leadless pacemaker implant, extraction of existing pacing system, and implantation of valve-in-valve TV.

Discussion

Patients with Ebstein's anomaly typically undergo TV repair or replacement. Following surgical intervention, owing to the anatomical location, patients can develop AV block requiring a pacemaker. Pacemaker implantation may involve a CS lead to avoid placing a lead across the new TV in efforts to avoid lead induced TR. Over time, these patients not uncommonly require re-intervention that can be challenging especially in pacing-dependant patients with leads across the TV.

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.

Percutaneous Atrial Septal Defect Closure in Adult Ebstein's Anomaly with Exertional Hypoxemia

In Ebstein's anomaly, percutaneous atrial septal defect (ASD) closure for the treatment of hypoxemia due to a right-to-left interatrial shunt remains controversial. We report the case of a 40-year-old woman with Ebstein's anomaly who developed cyanosis and shortness of breath on exercise. Her symptoms improved after percutaneous ASD closure and her clinical course has been good during follow-up. The balloon ASD occlusion test, combined with dobutamine stimulation before the procedure, is useful to confirm treatment indication. A prior electrophysiological evaluation is also important because Ebstein's anomaly is often complicated by atrioventricular recurrent tachycardia.

Ebstein's Anomaly: Genetics, Clinical Manifestations, and Management

Ebstein's anomaly is uncommon. Genetic bases of this congenital heart defect may be related to the mutations in myosin heavy chain 7 and NKX2.5, among others. Asymptomatic patients with Ebstein's anomaly can be conservatively treated and kept under close follow-up, whereas surgical operation is indicated for those patients with evidence of right heart dilation and progressively impaired ventricular systolic function. A biventricular repair consisting of the reconstruction of a competent monocuspid tricuspid valve, right ventriculorrhaphy, subtotal atrial septal defect closure, and aggressive reduction atrioplasty is suitable for most patients, and 1.5-ventricular repair (bidirectional Glenn shunt) is indicated for patients with poor right ventricular function; by contrast, heart transplantation is used in patients with severe left ventricular dysfunction.

Congenital Malformations Leading to Paradoxical Embolism

The absolute separation of the right and left circulations and the filtration of blood by the pulmonary circulation are essential to prevent the passage of thrombotic material from the venous system into the systemic arterial circulation. Any breach of the intracardiac septae or circumvention of the pulmonary capillary network may cause a paradoxical embolus. The most common causes are atrial septal defects and pulmonary arteriovenous malformations. This article discusses unusual connections and pathways related to congenital malformations. Although anticoagulation is necessary to prevent paradoxical emboli, the hematologic disturbances and the most appropriate therapy in these patients warrant further investigation.

Transcatheter closure of atrial septal communication during pregnancy in women with Ebstein's anomaly of the tricuspid valve and cyanosis

Transcatheter atrial septal defect occlusion is described in three pregnant patients with Ebstein's anomaly and exercise-induced cyanosis. Procedures took place in the second and third trimester. Careful hemodynamic testing was performed prior to permanent atrial septal occlusion to confirm the capacity of the right ventricle to accept the entirety of systemic venous return in the volume-expanded state of pregnancy. Outcomes for mother and fetus were favorable in all patients with significant reduction in maternal symptoms and resolution of cyanosis.

Increased risk of possible paradoxical embolic events in adults with ebstein anomaly and severe tricuspid regurgitation

OBJECTIVE

Determine incidence and risk factors for possible paradoxical embolic events in patients who have Ebstein anomaly with severe tricuspid regurgitation.

DESIGN

Retrospective study of clinical and imaging data.

SETTING

Tertiary care center.

PATIENTS

Patients undergoing clinical evaluation and echocardiography prior to cardiac surgery for Ebstein anomaly (1975-2010) performed at age ≥ 40 years.

RESULTS

Mean age of 128 patients (81 female) was 53 ± 9 years. All had severe tricuspid regurgitation. Twenty-four (19%) had previous cardiac surgery (at <40 years), including 17 for interatrial shunt closure. Most (112 [88%]) had New York Heart Association functional class III/IV heart failure; 84 (66%) had interatrial shunting (58 had an atrial septal defect and 29 had a patent foramen ovale [3 had both]). During their lifetime, 29 patients (23%) had a history of ≥1 possible paradoxical embolic events (stroke or transient ischemic attack, brain abscess, or myocardial infarction). The best predictors of preoperative possible paradoxical embolic events were an atrial septal defect (P = .002) and older age at surgery (P = .007). There was no association of possible paradoxical embolic events with cardiovascular risk factors (hypertension, dyslipidemia, smoking, or family history of coronary artery disease) (all P ≥ .3) or atrial fibrillation (P = .69). Median age at occurrence of paradoxical embolism was 49 (range, 1.5-74 years).

CONCLUSIONS

Possible paradoxical embolic events are common in adults with Ebstein anomaly and severe tricuspid regurgitation and are strongly associated with atrial septal defect. In patients with atrial septal defect or patent foramen ovale, shunt closure should be considered to reduce risk of possible paradoxical embolic events.

Congenital Heart Defects in Adults : A Field Guide for Cardiologists

Advances in cardiology and cardiac surgery allow a large proportion of patients with congenital heart defects to survive into adulthood. These patients frequently develop complications characteristic of the defect or its treatment. Consequently, adult cardiologists participating in the care of these patients need a working knowledge of the more common defects. Occasionally, patients with congenital heart defects such as atrial septal defect, Ebstein anomaly or physiologically corrected transposition of the great arteries present for the first time in adulthood. More often patients previously treated in pediatric cardiology centers have transitioned to adult congenital heart disease centers for ongoing care. Some of the more important defects in this category are tetralogy of Fallot, transposition of the great arteries, functionally single ventricle defects, and coarctation. Through this field guide, we provide an overview of the anatomy of selected defects commonly seen in an adult congenital practice using pathology specimens and clinical imaging studies. In addition, we describe the physiology, clinical presentation to the adult cardiologist, possible complications, treatment options, and outcomes.