Ebstein's malformation of the tricuspid valve. A review of 65 cases

Ebstein's anomaly: an electrophysiological perspective

Ebstein's anomaly of the tricuspid valve (EA) is an uncommon congenital cardiac malformation. It can present with atrioventricular tachycardia (AVRT), atrioventricular nodal re-entrant tachycardia (AVNRT), atrial arrhythmias, and rarely with ventricular tachycardia. The 12-lead electrocardiogram (ECG) is critically important and often diagnostic even prior to an electrophysiology study (EPS). Due to its complex anatomy, it poses particular challenges for mapping and ablation, even for an experienced electrophysiologist. In this review, we aim to provide insight into the electrophysiological perspective of EA and an in-depth analysis of the various arrhythmias encountered in diverse clinical scenarios.

Cardiac Catheterization in Adults with Ebstein Anomaly: Pathophysiologic Insights Regarding Surgical Repair and Prognosis

The underlying invasive hemodynamics and physiology in Ebstein anomaly (EA) are poorly understood. Moreover, the hemodynamic impact of tricuspid valve intervention in EA has not been well studied. Retrospective cohort of 52 adults with repaired and 36 with unrepaired EA undergoing right heart catheterization at Mayo Clinic, MN between 1993 and 2021. "Repaired" EA was defined as prior tricuspid valve repair and/or replacement (83% post-tricuspid valve replacement). Repaired patients were younger than those with unrepaired EA (41.3 ± 16.0 versus 50.6 ± 15.6 years, p = 0.008) and had a lower prevalence of ≥ moderate native or prosthetic tricuspid regurgitation (67% versus 81%, p = 0.01). Right atrial (RA) pressure was higher among patients with repaired EA than in unrepaired disease [13 (11; 18) versus 10 (8; 15) mmHg; p = 0.02], but these differences were no longer present when adjusting for ≥ moderate right ventricular systolic dysfunction and ≥ moderate tricuspid regurgitation. Cardiac index (Qs) was lower among those with unrepaired EA than in repaired EA (1.9 ± 0.7 versus 2.3 ± 0.6 l/min/m2, p = 0.01), even after adjusting for similar confounders. During a follow-up of 8.6 (3.2-13.3) years, 16 (18%) patients died. Systolic pulmonary artery pressure was independently associated with all-cause mortality. In summary, higher cardiac indices were found in those with repaired EA compared to those with unrepaired disease. RA hypertension was prevalent in both groups and no differences in right filling pressures were found between groups after adjusting for potential confounders. Elevation in pulmonary pressures was independently associated with survival. The use of pulmonary vasomodulators in EA requires further investigation.

Right Ventricular Electromechanical Dyssynchrony and Its Relation to Right Ventricular Remodeling, Dysfunction, and Exercise Capacity in Ebstein Anomaly

BACKGROUND

Abnormal atrioventricular and intraventricular electrical conduction and dysfunction of the functional right ventricle (fRV) are common in Ebstein anomaly (EA). However, fRV mechanical dyssynchrony and its relation to fRV function are poorly characterized. We evaluated fRV mechanical dyssynchrony in EA patients in relation to fRV remodeling, dysfunction, and exercise intolerance.

METHODS

We retrospectively analyzed data from nonoperated EA patients and age-matched controls who underwent echocardiography, cardiovascular magnetic resonance imaging, and cardiopulmonary exercise testing to quantify right ventricular (RV) remodeling, dysfunction, and exercise capacity. The relation of these to fRV dyssynchrony was retrospectively investigated. Right ventricular mechanical dyssynchrony was defined by early fRV septal activation (right-sided septal flash), RV lateral wall prestretch/late contraction, postsystolic shortening, and intra-RV delay using two-dimensional strain echocardiography. The SD of time to peak shortening among the fRV segments was calculated as a parameter of mechanical dispersion.

RESULTS

Thirty-five EA patients (10 of whom were <18 years of age) and 35 age-matched controls were studied. Ebstein anomaly patients had worse RV function and increased intra-RV dyssynchrony versus controls. Nineteen of 35 (54%) EA patients had early septal activation with simultaneous stretch and consequent late activation and postsystolic shortening of RV lateral segments. Intra-fRV mechanical delay correlated with fRV end-diastolic volume index (r = 0.43, P < .05) and fRV end-systolic volume index (r = 0.63, P < .001). The fRV ejection fraction was lower in EA with versus without right-sided septal flash (44.9 ± 11.0 vs 54.2 ± 8.2, P = .012). The fRV mechanical dispersion correlated with the percentage of predicted peak VO₂ (r = -0.35, P < .05).

CONCLUSIONS

In EA, fRV mechanical dyssynchrony is associated with fRV remodeling, dysfunction, and impaired exercise capacity. Mechanical dyssynchrony as a therapeutic target in selected EA patients warrants further study.

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.

Heart failure in the adult Ebstein patient

Ebstein anomaly comprises approximately 1% of all congenital heart diseases. It occurs when the tricuspid valve fails to properly delaminate from the right ventricle, resulting in a clinical spectrum of abnormal tricuspid valve morphology and right ventricular dysfunction. Due to the anatomy of the tricuspid valve and right ventricle, as well as associated right- and left-sided pathology, patients are at risk for both right and left ventricular failure and the associated symptoms of each. Ebstein patients are also at risk for atrial arrhythmias, due to the atrial enlargement intrinsic to the anatomy, as well as the presence of potential accessory pathways. Arrhythmias are generally poorly tolerated, particularly in the setting of ventricular dysfunction. Cyanosis may also be present in Ebstein patients, due to the common occurrence of atrial communications, which can exacerbate other symptoms of heart failure. Treatment of heart failure can be through pharmacologic and procedural interventions, depending on the underlying cause of heart failure. While early heart failure symptoms may be treated with medical management, most Ebstein patients will require surgery. Various surgical and catheter-based interventions targeting the tricuspid valve and the atrialized right ventricular tissue have been developed to help treat the underlying cause of the heart failure. The optimal timing of transcatheter and surgical intervention in the Ebstein patient to prevent or treat heart failure needs further study.

Ebstein's Anomaly: "The One and a Half Ventricle Heart"

Objective

Ebstein's anomaly remains a relatively ignored disease. Lying in the 'No Man's land' between congenital and valve surgeons, it largely remains inadequately studied. We report our short-term results of treating it as a 'one and a half ventricle heart' and propose that the true tricuspid annulus (TTA) 'Z' score be used as an objective criterion for estimation of 'functional' right ventricle (RV).

Methods

22 consecutive patients undergoing surgery for Ebstein's anomaly were studied. Echocardiography was performed to assess the type and severity of the disease, tricuspid annular dimension and its 'Z' score. Patients were operated by a modification of the cone repair, with addition of annuloplasty, bidirectional cavopulmonary shunt (BCPS) and right reduction atrioplasty to provide a comprehensive repair. TTA 'Z' score was correlated later with postplication indexed residual RV volume.

Results

There was one (4.5%) early and no late postoperative death. There was a significant reduction in tricuspid regurgitation grading (3.40±0.65 to 1.22±0.42, P<0.001). Residual RV volume reduced to 71.96±3.8% of the expected volume and there was a significant negative correlation (rho −0.83) between TTA 'Z' score and indexed residual RV volume. During the follow-up of 20.54±7.62 months, the functional class improved from 2.59±0.7 to 1.34±0.52 (P<0.001).

Conclusion

In Ebstein's anomaly, a higher TTA 'Z' score correlates with a lower postplication indexed residual RV volume. Hence, a complete trileaflet repair with offloading of RV by BCPS (when the TTA 'Z' score is >2) is recommended. The short-term outcomes of our technique are promising.

When lithium hurts: a look at Ebstein anomaly

Ebstein anomaly (EA) is a congenital defect of the tricuspid valve (TV) and the right ventricle (RV) in which the attachments of the septal and posterior valve leaflets are apically displaced. The latter creates 3 morphologic components inside the right heart, namely the right atrium proper, the atrialized RV, and the functional RV. This rare anomaly accounts for <1.5% of all congenital heart diseases. The current opinion among authors is that it is a genetically heterogeneous condition caused by failure of delamination of the TV leaflets from the underlying myocardium and the interventricular septum. Its characteristic electrocardiographic findings include tall, broad, right atrial P waves, prolonged PR intervals, and deep Q waves in the right precordial leads. Echocardiography is currently the best technique for diagnosing this anomaly, although cardiac magnetic resonance imaging is also gaining traction as an alternative modality. The management strategies for EA correlate with the age of the patient, severity of the heart disease, and/or associated cardiac abnormalities. TV repair, rather than valve replacement, is preferred because of its favorable long-term prognosis. Nevertheless, a large, randomized study is still needed to compare the different valve repair techniques used in patients with EA.

Current Trends in the Management of Neonates With Ebstein's Anomaly

BACKGROUND

The optimal management strategy for neonates with Ebstein's anomaly is unknown. This analysis was undertaken to assess current trends in the management and prognosis of neonates born with Ebstein's anomaly in the United States, as reflected in an administrative database.

METHODS

The Pediatric Health Information System database (40 children's hospitals) was used to review the reported incidence and available data on neonates with Ebstein's anomaly treated in the United States between 2003 and 2007. Primary outcome was hospital survival. Of the 415 patients identified, 257 (62%) did not undergo initial surgical intervention as neonates. Aortopulmonary shunt only was done on 63 patients (15%), single-ventricle palliation on 36 (9%), two-ventricle repair on 16 (4%), heart transplantation in 3 (1%), and a catheter-based intervention or a hybrid palliative approach was applied in 40 (10%). Intergroup comparisons were done using chi-square analyses.

RESULTS

Mortality for the entire cohort was 24% (100 of 415). For medically treated patients, this was 22% (56 of 257). For surgically treated and hybrid patients, this was 30% and 23%, respectively (P = NS).

CONCLUSIONS

The majority of patients born with Ebstein's anomaly currently do not undergo surgical intervention as neonates. Significant early mortality in this group suggests that certain subsets of patients may benefit from earlier surgical intervention. Among the severely symptomatic neonates who do undergo early surgical intervention, the mortality remains high, irrespective of the surgical approach taken. A multicenter trial may be appropriate to identify strategies to optimize care for these critically ill neonates. Further analysis of risk factors for early mortality is warranted.

The prognosis in Ebstein's disease of the heart. Long-term follow-up of 22 patients

A follow-up study of 22 patients with Ebstein's anomaly has been performed. Nine patients died 1-21 years (mean 9) after the initial admission while the 13 patients alive at the end of the observation period had been followed for 5-26 years (mean 15). Clinical, ECG, radiological, and haemodynamic features were analyzed with reference to their prognostic significance. The presence or absence of cyanosis due to right-to-left shunt through an atrial septal defect (ASD) distinguished best between a good and poor prognosis. Right-sided heart failure and dyspnoea at rest, often associated with palpitations, precordial pains and syncopes, were grave prognostic findings. After the initial signs of heart failure there was a rapid deterioration, death ensuing within a few years. Operation with insertion of a prosthetic valve (and closure of the ASD) should be seriously considered at the appearance of heart failure.

Electrocardiographic characteristics of patients with Ebstein's anomaly before and after ablation of an accessory atrioventricular pathway

The abnormal development of the tricuspid valve in patients with Ebstein's anomaly results in several activation abnormalities including delayed intraatrial conduction, right bundle branch block (RBBB), and ventricular preexcitation. The aim of the present study was to define the ECG characteristics before and after ablation of an accessory A-V pathway (AP) in patients with Ebstein's anomaly.

METHODS

A series of 226 consecutive patients with Ebstein's anomaly was studied. Sixty-four patients (28%) had documented tachycardia. Thirty-three patients with recurrent tachycardia were found to have a single right-sided AP that was successfully ablated (study group). Thirty patients without tachycardia served as the control group.

RESULTS

Only 21 of 33 patients (62%) had a typical ECG pattern of preexcitation. In addition, none of the patients had an ECG pattern of RBBB during sinus rhythm. In contrast, 28 of 30 (93%) patients in the control group had RBBB (P < 0.001). Radiofrequency catheter ablation resulted in appearance of RBBB in 31 of 33 (94%) patients. The absence of RBBB in patients with Ebstein's anomaly and recurrent tachycardia had a 98% sensitivity and 92% specificity for the diagnosis of an AP. The positive predictive value was 91% (0.77, 0.97 CI 95%) and the negative predictive value was 98% (0.85, 0.99 CI 95%).

CONCLUSION

One-third of patients with Ebstein's anomaly and symptomatic tachyarrhythmias have minimal or absent ECG features of ventricular preexcitation. In these patients, the absence of RBBB pattern is a strong predictor of an AP.

Ebstein anomaly and duplication of the distal arm of chromosome 15: Report of two patients

Ebstein anomaly of the tricuspid valve is an uncommon congenital heart defect. We report two unrelated patients with Ebstein anomaly and duplication of the distal long arm of chromosome 15 (15q22 --> qter and 15q24 --> qter). Duplication of 15q is a well-described phenotype that includes congenital heart defects, and these are the first cases with Ebstein anomaly. Duplication of 15q likely affects the early morphogenesis of cardiac structures, including the normal formation of the tricuspid valve.

The adult patient with Ebstein anomaly. Outcome in 72 unoperated patients

Knowledge of the long-term outcome in unoperated adult patients with Ebstein anomaly is limited, and the therapeutic approach is still controversial. We studied unoperated adult patients with Ebstein anomaly to define the patterns of presentation, anatomic characteristics, outcome, and predictive factors for survival. Seventy-two unoperated survivors of Ebstein anomaly aged over 25 years attended from 1972 to 1997 were reviewed and followed-up from 1.6 to 22.0 years. Patients were classified in 3 groups of severity according to the echocardiographic appearance of the septal leaflet attachment of tricuspid valve. The mean age at diagnosis was 23.9 +/- 10.4 years, and the most common clinical presentation was an arrhythmic event (51.4%). There were 30 (42%) deaths, including 6 from arrhythmia, 12 related to heart failure, 7 sudden, 2 unrelated, and 3 unascertained. According to Cox regression analysis, predictors of cardiac-related death included age at diagnosis (hazard ratio 0.89 for each year of age, 95% confidence intervals CI[ 0.84-0.94), male sex (3.93, 95% CI, 1.50-10.29), degree of echocardiographic severity (3.34, 95% CI, 1.78-6.24), and cardiothoracic ratio > or = 0.65 (3.57, 95% CI, 1.15-11.03). During follow-up, morbidity was mainly related to arrhythmia and refractory late hemodynamic deterioration. The magnitude of tricuspid regurgitation, cyanosis, and the New York Heart Association (NYHA) functional class at time zero were significant risk factors according to the univariate analysis, but not after multivariable confrontation. The results of this study suggest that pattern of presentation, clinical course, and prognosis of unoperated adult patients with Ebstein anomaly are influenced by several factors. Although the initial symptoms are usually mild and commonly related to supraventricular arrhythmias, these are not associated with the long-term outcome. The severity of the morbid anatomy was the main determinant of survival only in extreme cases, but not in those with mild or moderate deformations, which are more common in adults. Other independent risk factors such as cardiothoracic ratio, sex, age at diagnosis, and the echocardiographic evaluation may help to determine the therapeutic approach. Adult patients with Ebstein anomaly should not be considered as a simple low-risk group.

Mimics of Ebstein's anomaly

The purpose of this study was to determine the most discriminating clinical and echocardiographic features that are most helpful in correctly identifying Ebstein's anomaly of the tricuspid valve from other causes of tricuspid regurgitation. Ebstein's anomaly is an uncommon malformation of the tricuspid valve with diagnostic echocardiographic features. Other cardiac disorders associated with tricuspid valve regurgitation and predominate right-sided heart chamber enlargement can be misdiagnosed as Ebstein's anomaly. All patients who were referred to our institution between 1982 and 1995 with the diagnosis of Ebstein's anomaly but were found to have other abnormalities of the tricuspid value or right ventricle were identified. Their clinical, echocardiographic, and surgical records were reviewed retrospectively. Twenty-two patients (12 males and 10 females), aged 7 to 68 years (mean 33 years), were referred to our institution with the diagnosis of Ebstein's anomaly but were found to have another abnormality that mimicked clinical and diagnostic features of Ebstein's anomaly. The most common initial symptom was exercise intolerance (13 [59%] patients) followed by atrial arrhythmia (seven [32%] patients). Two patients had cyanosis. Three patients had paroxysmal and six had chronic atrial fibrillation/flutter. Cardiomegaly on chest x-ray film was noted in 18 (82%) patients. Referral diagnosis of Ebstein's anomaly had been made by echocardiography (12 patients), cardiac catheterization (four patients), both techniques (five patients), and echocardiography and magnetic resonance imaging (one patient). All 22 patients had predominate right atrial and right ventricular enlargement, and 18 (82%) of 22 patients also had right ventricular dysfunction. However, Ebstein's anomaly was confidently ruled out with repeat comprehensive echocardiography at our institution by establishing (1) absence of significant apical displacement of the septal tricuspid valve leaflet (> or = 8 mm/m2) and (2) lack of a redundant, elongated, anterior tricuspid valve leaflet in all 22 patients (100%). All had significant tricuspid regurgitation caused by tricuspid valve dysplasia (nine patients), tricuspid valve prolapse (four patients), trauma (four patients), right ventricular dysplasia (three patients), endocarditis (one patient), and annular dilation caused by free pulmonary regurgitation (one patient). In all 15 patients who subsequently underwent surgery (tricuspid valve repair [seven patients] or replacement [eight patients]), the absence of Ebstein's anomaly was confirmed. Echocardiographic absence of the characteristic degree of displacement of the septal leaflet of the tricuspid valve (> or = 8 mm/m2) and the presence of a nonelongated, nonredundant anterior tricuspid valve leaflet consistently excluded the diagnosis of Ebstein's anomaly. Under such circumstances, other anomalies of the tricuspid valve or right ventricle were consistently identified. Recognition of the mimics of Ebstein's anomaly had important surgical implications.

Radiofrequency ablation of tachyarrhythmias in patients with Ebstein's anomaly

We performed radiofrequency catheter ablation in five patients associated with Ebstein's anomaly to cure their refractory tachyarrhythmias. The presenting arrhythmias were four cases of orthodromic circus movement tachycardia using accessory pathways as a requisite limb, including one case of a Mahaim fiber and one of atrial flutter of common variety. All accessory pathways, including the Mahaim fiber, were ablated by RF energy delivered through the catheter placed at the AV annulus rather than the displaced anatomical AV groove. Interestingly, the antegrade or retrograde conduction interval over these accessory pathways was relatively longer than that of usual accessory pathways, and the accessory pathway potential was fractionated in some cases. The location of the atrioventricular node was displaced from the usual position to the postero-inferior area of Koch's triangle in one case. The configuration of the flutter wave was larger than usual in height as well as in width. All tachyarrhythmias were cured by RF catheter ablation. In the case of RF catheter ablation for patients with Ebstein's anomaly, close attention is indispensable in order to accomplish it safely and successfully, because of the anatomical and functional differences peculiar to Ebstein's anomaly.

Clinical profile and natural history of Ebstein's anomaly of tricuspid valve

There were 63 patients of Ebstein's anomaly of tricuspid valve encountered from 1976 to 1991; 28 (44.4%) were male and 35 (55.6%) female. Their age at presentation ranged from 3 months to 51 years. Five (7.9%) patients were asymptomatic, 48 (76.2%) had class II-III exertional dyspnoea, palpitation or both. Thirty patients (47.6%) had cyanosis. Electrocardiogram showed paroxysmal atrial fibrillation in two, chronic atrial fibrillation in four (6.3%), paroxysmal supraventricular tachycardia in seven, atrial or ventricular ectopic beats in five (7.9%), 2:1 atrioventricular block in one (1.6%), complete atrioventricular block in two (3.2%) and type B WPW syndrome in nine patients (14.3%). Chest X-ray showed diminished vascularity in 22 (34.9%). Diagnosis was established by cardiac catheterization and or echocardiography. Atrialized right ventricular chamber was demonstrated in 51 (80.9%) by angiography and in 40 (63.5%) by electrophysiology. Patients were followed up for 1-172 months. Seventeen patients (26.9%) required surgery. Three patients (4.8%) died during medical follow-up, and five (7.9%) died following surgery. Survival probability for 46 medical patients was 88.9% at 172 months. Factors affecting survival were pulmonary blood flow, cyanosis, clubbing and systemic arterial oxygen saturation.

Ebstein's malformation of the tricuspid valve: genetic and environmental factors. The Baltimore-Washington Infant Study Group

Ebstein's anomaly is a specific structural deformity of the tricuspid valve, and its rarity has hampered etiologic evaluation. Cases of Ebstein's anomaly registered in the Baltimore Washington Infant Study (BWIS), a regional case-control study of cardiovascular malformations (CVM) in infancy, are reviewed. Between 1981 and 1989 a total of 4,390 CVM cases, including 47 Ebstein cases, and 3,572 controls were registered. The prevalence of Ebstein's anomaly was 5.2 per 100,000 livebirths. Additional cardiac anomalies were present in 38.3% of Ebstein cases. Non-cardiac malformations were present in 19.1% of Ebstein cases vs. 25.5% of other CVM, and 1.7% of controls. Case-fatality by 1 year of age was 23.4% in Ebstein vs. 18.1% in other CVM. Interviews of parents of Ebstein cases, other CVM, and controls (n = 44, 3,335, and 3,572, respectively) elicited information on family history of malformations, maternal illnesses, reproductive history, therapeutic drugs, parental lifestyle, and environmental exposures during the periconceptional period. Case-control analyses suggest genetic, reproductive, and environmental risk factors: twins [odds ratio (OR) 8.2, 95% confidence interval (CI) 2.6-25.3]; family history of CVM (OR 6.4, 95% CI 1.8-22.2); white race (OR 2.9 with non-whites as reference, 95% CI 1.2-7.0); previous miscarriages (OR 2.0, 95% CI 1.2-3.3); maternal exposure to benzodiazepines (OR 5.4, 95% CI 1.5-19.1); and varnishing (OR 3.4, 95% CI 1.3-9.1). Additional multicenter investigations are warranted to elucidate the role of genetic, reproductive, and environmental factors in the etiology of this anomaly.

Two unusual complications after surgical interruption of an accessory pathway

In a patient with the Wolff-Parkinson-White syndrome, Ebstein's anomaly of the tricuspid valve, a right atrial Chiari net and a patent foramen ovale two unusual complications developed after surgical epicardial dissection combined with cryoablation of the anomalous pathway. The first complication was that ablation of the right atrial wall led to changes in interatrial pressure gradients and the development of a right to left shunt necessitating surgical closure of the atrial septal defect. The second complication was the development of a thrombotic mass in the Chiari net simulating on intracavity tumour, which also had to be removed surgically.

Ebstein's anomaly: a long-term study of survival

This study examines data regarding the survival of patients with Ebstein's malformation. Of 61 patients studied at the University of Minnesota, 31 are currently alive, with the average survival being 15 years. Several factors adversely affected survival: NYHA functional classification, hemoglobin level, right atrial pressure, symptoms during the neonatal period, and cardiac surgery. Data from a multi-institutional study collected during the past decade adds information regarding survival. Of 18,281 patients in the study, 71 (0.4%) had Ebstein's malformation. Sixteen of these were among 7235 infants, and of these seven died during the first year of life. In contrast, among 55 patients over the age of 1 year, four died, each after cardiac surgery. The data help our understanding of the course of patients with Ebstein's malformation and decisions regarding surgical treatment.

Effect of Ebstein's anomaly on short- and long-term outcome of surgically treated patients with Wolff-Parkinson-White syndrome

BACKGROUND

Ebstein's anomaly is the most commonly occurring congenital abnormality associated with the Wolff-Parkinson-White (WPW) syndrome. However, the effects of Ebstein's anomaly on the risks and benefits of surgical ablation of accessory pathways in patients with WPW syndrome are unknown.

METHODS AND RESULTS

This study compared the long-term outcome of 38 WPW patients with Ebstein's anomaly undergoing accessory pathway ablation to a reference population of 384 similarly treated patients without the anomaly. Ebstein's anomaly was mild in 21 patients (55%) and moderate-to-severe in 17 patients (45%). Sixteen patients (42%) required tricuspid valve surgery, and 23 (61%) had an atrial septal defect or patent foramen ovale repaired. Baseline clinical characteristics and preoperative clinical arrhythmias were similar in both groups. Ten-year survival was 92.4% and 91.2% for patients with and without Ebstein's anomaly, respectively (p = NS). During a mean follow-up of 6.2 +/- 3.8 and 5.3 +/- 3.6 years, 82% of patients with and 90% without Ebstein's anomaly had either clinically insignificant or no arrhythmias, and 18% versus 10% reported symptoms suggesting arrhythmias lasting longer than 1 minute, respectively. Atrial fibrillation was reduced postoperatively to 9% (p less than 0.001) in patients with and to 4% (p less than 0.001) in those without the anomaly. Fewer hospitalizations were reported postoperatively by 90% versus 96% of patients with and without Ebstein's anomaly; 9.4% versus 6.0% of patients were disabled at follow-up, respectively (p = NS).

CONCLUSIONS

Patients with Ebstein's anomaly are improved significantly after accessory pathway ablation. The presence of this anomaly should not preclude accessory pathway ablation in these patients.

Predictors of long-term survival with Ebstein's anomaly of the tricuspid valve

In patients with Ebstein's anomaly of the tricuspid valve, predictors of death and indications for surgery are poorly defined. We retrospectively reviewed 48 patients with Ebstein's anomaly, 17 (35%) of whom presented in the first week of life. Duration of follow-up extended to 32 years (greater than 10 years in 35%). Twenty of the 48 patients (42%) died, 6 in the first week of life and 1 at age 5 months. Thirteen of the 41 patients surviving to age 6 months subsequently died, 50% probability of survival being reached at 47 years. Significant (p less than or equal to 0.05) predictors of death in this group were: male sex, cardiothoracic ratio greater than or equal to 0.65, New York Heart Association class III or IV, breathlessness and the absence of Wolff-Parkinson-White syndrome. Eight patients died suddenly. A cardiothoracic ratio greater than or equal to 0.65 was a better predictor of sudden death than functional status. All who developed atrial fibrillation died within 5 years. Other atrial arrhythmias were not helpful in predicting sudden death. In view of these findings, tricuspid valve surgery is recommended before the cardiothoracic ratio reaches 0.65, regardless of the symptomatic state.

Pacing in a patient with Ebstein's anomaly

We report a case of Ebstein's anomaly in which ventricular pacing was achieved by positioning a pacing lead in the enlarged right atrium. By placing the electrode in the atrialization of the right ventricle, an aggravation of tricuspid regurgitation that may result from catheter displacement of the valve leaflets is avoided.

Angiographic abnormalities of the morphologically left ventricle in the presence of Ebstein's malformation

Cineangiography of the morphologically left ventricle was performed in 10 patients with Ebstein's malformation. The angiographic findings included left ventricular contour abnormalities (8), mitral valve prolapse (7) and global hypokinesia (5). Left ventricular abnormalities were present whether the left ventricle was normally placed or in mirror-image position in congenitally corrected transposition. Abnormalities of the morphologically left ventricle in Ebstein's malformation have received little attention in the past. Frequent occurrence of these abnormalities should make careful evaluation of the morphologically left ventricle mandatory in all patients with Ebstein's malformation.

A case of Ebstein's anomaly with double mitral valve

A 5-month-old male infant with no history of serious illness died suddenly and unexpectedly. He was found dead under a heavy 'futon', a coverlet, which covered the whole of his body. As it was suspected he may have been smothered, a medicolegal autopsy was performed, and it was discovered that the infant had Ebstein's anomaly with double mitral valve. The cause of death appeared to be due to heart failure caused by this congenital heart disease.

Diagnosis and natural history of Ebstein's anomaly

Thirty five cases of Ebstein's anomaly were diagnosed by cardiac catheter study or echocardiography between 1962 and 1984. The anomaly was an isolated abnormality in 27 patients; the remainder had additional heart lesions. Six patients have died and four of these had other cardiac lesions. Thirteen are currently symptom free. Twelve cases presented with cyanosis and heart murmur on the first day of life. Eight of these had associated thrill which is a rare finding in neonates. As pulmonary vascular resistance fell there was clinical improvement. This was assisted by oxygen treatment. Another two cases presented in the first week of life and 10 in the first decade with a murmur or supraventricular tachycardia. Eleven cases presented as adolescents or adults with a murmur, cardiomegaly, or cardiac symptoms. Three patients were seen initially in the sixth decade. Clinical diagnosis was correct in only one adult. Twenty five patients had cardiac catheterisation. Important arrhythmias occurred in 10 cases, and two required cardioversion. Difficulty was experienced in entering the pulmonary artery in 11 infants and children. Diagnosis at initial catheter study was incorrect in four patients. Echocardiograms were recorded in 29 cases. Earlier M mode measurements of time delay of tricuspid closure compared with mitral closure did not always lead to the correct diagnosis. Cross sectional studies gave good images of tricuspid leaflet displacement, its tethering, and the atrialised portion of the right ventricle and have facilitated the diagnosis of more cases in recent years. Echocardiography is the procedure of choice for diagnosis of Ebstein's anomaly.

Persistent atrial standstill in familial Ebstein's anomaly

Persistent atrial standstill occurred in a father and his youngest son with familial Ebstein's anomaly. In both cases routine electrocardiograms showed no atrial electrical activity and cross sectional echocardiograms showed inferior displacement of the septal tricuspid leaflet and tethering of the tricuspid leaflets to the right ventricle. The father had a cerebral embolism and died of a myocardial infarction. Necropsy showed attachment of the septal tricuspid leaflet below the membranous septum. On serial histological examination fibrofatty infiltration of the right atrial wall, the atrioventricular node, and the inferior part of the His bundle up to the bifurcation was present. The son had haemodynamic and electrophysiological findings consistent with mild Ebstein's anomaly and persistent atrial standstill, for which permanent cardiac pacing was necessary. The persistent atrial standstill with slow escape rhythm was most probably a consequence of the abnormalities in both the atrial wall and the His bundle which, together with the abnormal attachment of the tricuspid valve, may be features of the same congenital cardiac anomaly.

Two-dimensional echocardiographic spectrum of Ebstein's anomaly: detailed anatomic assessment

This report details the two-dimensional echocardiographic assessment of 41 patients with Ebstein's anomaly. The anatomic spectrum of Ebstein's anomaly is correlated with surgical and autopsy observations in 66% of these patients. Morphologic abnormalities of the tricuspid valve and right heart structures were uniquely assessed by noninvasive two-dimensional echocardiographic examination. Features of the tricuspid valve that best related to decreased functional capacity were: 1) absence of the septal leaflet, and 2) pronounced tethering, restriction of motion and displacement of the anterior leaflet of the tricuspid valve. This 4 1/2 year experience suggests that two-dimensional echocardiography can replace angiography as the procedure of choice for diagnostic and morphologic assessment of Ebstein's anomaly. Cardiac catheterization is necessary only when specific hemodynamic questions or clinical inconsistencies exist.

Total disconnection of the right ventricular free wall: surgical treatment of right ventricular tachycardia associated with right ventricular dysplasia

Arrhythmogenic right ventricular dysplasia is a myopathy that affects the right ventricular free wall (RVFW) and gives rise to recurrent reentrant ventricular tachycardia (VT). Because the entire right ventricle is potentially arrhythmogenic, ablating a single site of VT may not eliminate the arrhythmia. We developed an operation to confine any arrhythmic activity arising from the right ventricle to that chamber: total disconnection of the RVFW from the left ventricle. We performed RVFW disconnection in two patients with refractory VT associated with arrhythmogenic right ventricular dysplasia. At least two sites or origin of morphologically distinct VT were identified in the RVFW in each patient. RVFW disconnection was carried out under normothermic cardiopulmonary bypass. An encircling incision was made along the attachment of the RVFW to the aortoventricular unit and the tricuspid annulus; the right coronary artery and its RVFW branches were left intact. Electrical activity of the two chambers became dissociated, and VT arising from the RVFW was confined to that chamber. Postoperatively, there was no clinical evidence of hemodynamic impairment (follow-up 4 months and 3 months). Left ventricular function was unchanged and right ventricular flow was maintained by atrial contraction and motion of the septum toward the RVFW during left ventricular systole. One patient had incessant right ventricular tachycardia confined to the RVFW for 3 weeks. We conclude that RVFW disconnection is feasible and applicable to patients with refractory VT originating in the diffusely diseased RVFW.

The electrophysiologic basis and management of symptomatic recurrent tachycardia in patients with Ebstein's anomaly of the tricuspid valve

Twenty-two patients with Ebstein's anomaly were evaluated because of recurrent tachycardia. A total of 30 accessory pathways were present in 21 of the 22 patients. Twenty-six accessory pathways were of the atrioventricular (A-V) type while four were Mahaim fibers. Multiple accessory pathways were present in eight patients. Twenty-five of the 26 accessory A-V pathways were right-sided, either in the posterior septum (12 pathways) or the posterolateral free wall (13 pathways); one patient with corrected transposition of the great arteries had a left-sided accessory A-V pathway in a lateral free wall location. Patients with accessory A-V pathways had a long minimal ventriculoatrial (V-A) conduction time during reciprocating tachycardia (192 +/- 47 ms) and usually showed a persistent complete or incomplete right bundle branch block morphology. At surgery, preexcitation was invariably localized to the atrialized ventricle. The long V-A conduction time during reciprocating tachycardia appeared to consist of late activation of the local ventricle in the region of the accessory pathway with a further delay occurring before excitation of adjacent atrium presumably due to conduction over the accessory pathway. Accessory A-V pathways were successfully sectioned with no deaths in 13 of 15 patients. On the basis of these data, certain electrocardiographic findings encountered in the study of patients with recurrent tachycardia should point to the possibility of associated Ebstein's anomaly: morphology of the surface electrocardiogram suggesting preexcitation of the right posterior septum or right posterolateral free wall as well as the combination during reciprocating tachycardia of a long V-A interval and right bundle branch block.

Right ventricular endomyocardial fibrosis simulating Ebstein's anomaly

A case of right ventricular endomyocardial fibrosis simulating Ebstein's anomaly is described. The clinical features, chest x-ray, electrocardiogram, echocardiogram, intracardiac electrogram, and the angiogram were all compatible with Ebstein's malformation. A correct diagnosis was subsequently made in the operating room. Reasons for the difficulties in the differential diagnoses of these two entities are discussed.

The cause of the hemodynamic disturbances in Ebstein's anomaly based on observations at operation

Ten adult patients with Ebstein's anomaly had open-heart operation for interruption of a Kent bundle. The 4 patients in Group 1 had arrhythmias. One patient had a patent foramen ovale, which was closed. In 3 patients the Kent pathway was identified and interrupted, but in the other only the pathway's anterograde function was interrupted, leaving the patient subject to supraventricular tachycardia (SVT). The 3 patients in Group 2 had mild to moderate cyanosis and dyspnea during SVT as well as mild impairment during strenuous physical activity. Only interruption of their Kent bundles and closure of the patent foramen ovale were done. The 3 patients in Group 3 had dyspnea and cyanosis on exertion, and 1 had overt right heart failure. In each patient, obstruction between the atrialized right ventricle (RV) and functioning RV by the displaced tricuspid valve (TV) was relieved by valve excision and replacement. Interruption of the Kent bundle was successful in 2 of the 3 patients. Operation for Ebstein's anomaly is indicated when any of the following conditions are present: arrhythmias due to Kent bundles that are refractory to medical management; a defect in the atrial septum that must be closed because of a history of cyanosis or paradoxical emboli, or an arrhythmia that must be corrected by right atriotomy; and obstruction between the atrialized and functioning RV or a small functioning RV, both of which can be corrected by TV replacement.

Surgical treatment of Ebstein's anomaly. Early and late results in seven consecutive cases

The surgical treatment of Ebstein's anomaly is discussed on the basis of our experience with 7 patients who underwent operation at this clinic during the last ten years. The age of the patients (2 males, 5 females) ranged from 17 to 47 years (mean 27 years) at the time of operation. Two patients were in functional class II and five in classes III or IV (N.Y.H.A.). The Wolff-Parkinson-White syndrome was concomitant in 2/7 cases and patent foramen ovale or atrial septal defect (ASD) with right-to-left shunt was present in 6/7 cases. The valvular anomaly was typical in 5 patients and stenosis of displaced tricuspid leaflets into right ventricular outflow region was detected in two patients. Tricuspid valve replacement (TVR) with disc valve prosthesis was performed in 5 patients (Björk-Shiley model in 4 cases, Kay-Shiley model in one) and tricuspid valve commissurotomy in two patients. All six patients with interatrial communication underwent closure of this communication simultaneously. One patient had concomitant epicardial mapping and attempted division of the anomalous conduction pathways was unsuccessful. This patient died on the 14th postoperative day from ventricular fibrillation. No other early or late mortality was recorded. Life-long anticoagulation therapy was introduced in all 5 patients with TVR. Thrombotic malfunction of the prosthetic valves necessitated re-operation and new prosthetic valve replacement in two patients 15 and 16 months after the first TVR. One of these patients had recurrent prosthetic thrombosis twice which was successfully treated with streptokinase. The other patient's prosthesis is functioning well 18 months after re-operation. All 6 long-term survivors were improved and remained in good condition, in functional class I, 1, 3, 3, 8, 9, and 10 years, respectively, after operation.

Two-dimensional echocardiographic assessment of Ebstein's anomaly

Nine patients with Ebstein's anomaly of the tricuspid valve were studied by two-dimensional echocardiography, using the standard long and short axis views as well as the apex four chamber view. With this latter view, the displacement of the tricuspid valve into the right ventricle was clearly seen in all nine cases of Ebstein's anomaly and was not noted in a control population. The severity of the tricuspid displacement was assessed by comparing the position of the mitral and tricuspid valves relative to the cardiac apex. The apex four chamber view allowed visualization of the atrioventricular (AV) ring simultaneously with the displaced tricuspid valve, and therefore the size of the "atrialized" right ventricle, true right ventricle and right atrium could be determined. These dimensions compared favorably with angiography.

Elective mapping and surgical division of the bundle of Kent in a patient with Ebstein's anomaly who required tricuspid valve replacement

A 14 year old girl with Ebstein's anomaly and Wolff-Parkinson-White syndrome without supraventricular tachycardia underwent closure of an atrial septal defect and tricuspid valve commissurotomy. Her postoperative course was complicated by her first episodes of recurrent debilitating paroxysmal supraventricular tachycardia. Severe tricuspid insufficiency with low cardiac output necessitated a repeat intracardiac operation. At reoperation the patient underwent successful tricuspid valve replacement with concomitent cardiac mapping and division of the bundle of Kent. In patients with heart disease requiring intracardiac repair who also have Wolff-Parkinson-White syndrome, elective surgical division of the anomalous bundle is recommended whether or not preoperative attacks of tachycardia have occurred.

Clinical classification of Ebstein's anomaly

Twenty-six patients with Ebstein's anomaly were classified into three types according to their clinical features, heart catheterization data, angiocardiographic and anatomical findings which were obtained on surgery or autopsy. The hemodynamics in each type were discussed. 1. Tricuspid Stenosis Dominant Type. Eight patients, who were cyanotic and had severe symptoms, mild to moderate cardiomegaly, and the "double-ball sign" on angiocardiography were classified into this type. A pressure gradient across the tricuspid valve was demonstrated in 5 patients. 2. Tricuspid Insufficiency Dominant Type. Four cyanotic patients, who had mild symptoms despite the severe cardiomegaly were grouped into this type. The "double-ball sign" was found in all. In three patients, incompetent tricuspid valve was observed. Tricuspid insufficiency necessitates the volume overwork of the right atrium and the functioning right ventricle, resulting in severe dilatation. 3. Mild Type. Fourteen patients who showed no or mild cyanosis, no or mild symptoms, and mild to moderate cardiomegaly, were classified into this type. It is considered that the adequate cardiac output in these patients is attributable to the good function of the tricuspid valve.

Reconstructive valve surgery

Despite continued refinement of heart valve prostheses, valve replacement carries risks of thromboembolic, mechanical, and infectious complications, and long-term success is further limited by the eventual wear of prosthetic parts. In many patients with congenital or acquired valve diseases, valve function may be improved, if not restored, by reconstructive techniques, prosthetic replacement being thereby avoided or delayed. This review examines the current status of reconstructive procedures for management of diseased valves, with emphasis on long-term results and post-operative hemodynamic studies. In many instances the choice between reconstruction and replacement of a diseased valve remains controversial. The documented success of selectively applied reconstructive techniques, however, weighs against expedient decisions for prosthetic replacement and supports a continuing search for new techniques.

Congenital tricuspid insufficiency. Definition and review

Simple congenital tricuspid insufficiency (CTI) has, up to now, been loosely included with the larger Ebstein's anomaly (EA) group. Certain pathologic and clinical features of CTI deserve definition and a place apart from EA. A review of the literature has produced 20 clinical cases for analysis to which we add two cases successfully treated surgically. The high mortality in the neonatal age group (14 of 14) continues to be a formidable challenge, but the older survivors (2 of 8) would appear to have better prospects, based on our limited experience.