Myocardial Fibrosis in Pediatric Patients With Ebstein's Anomaly.

BACKGROUND: Left ventricular dysfunction in Ebstein's anomaly (EA) is associated with higher mortality. The health of the left ventricular myocardium in children and adolescents with EA has not been investigated in detail. METHODS: Patients with unrepaired EA who had undergone cardiac magnetic resonance imaging including T1 mapping were retrospectively reviewed. Patients were compared with age- and sex-matched controls. EA severity index was calculated using volumetric measurements at end diastole ([right atrial+atrialized right ventricular volumes]/[functional right ventricular+left atrial+left ventricular volumes]). Global circumferential and radial strain and as well as strain rate were examined using cardiac magnetic resonance feature tracking. RESULTS: Twelve EA patients and an equal number of controls were included. Functional and atrialized right ventricular end-diastolic volumes were 84±15 and 21±13 mL/m2, respectively. Late gadolinium enhancement, confined to the right ventricle, was found in 2 patients (16%). Left ventricular native T1 values and extracellular volume fractions were higher in patients compared with controls (1026±47 versus 956±40 ms, P=0.0004 and 28.5±3.4% versus 22.5±2.6%, P<0.001, respectively). Native T1 times correlated inversely with patients' age, body surface area, and O2 saturations (r=-0.63, -0.62, and -0.91, respectively; P=0.02, P=0.02, and P<0.0001, respectively). EA severity index ranged between 0.15 and 0.94 and correlated with T1 values (r=0.76, P=0.003). Native T1 correlated with global circumferential strain (r=0.58, P=0.04) but not ejection fraction (EF). EA patients had reduced maximum oxygen uptake (Vo2max). Vo2max correlated inversely with T1 values (r=-0.79, P=0.01). CONCLUSIONS: Children and adolescents with EA experience an abnormal degree of diffuse myocardial fibrosis. Its association with O2 saturation points toward a role of hypoxemia in the pathogenesis of fibrosis. Larger and prospective studies are needed to evaluate the value of T1 mapping for risk stratification and monitoring in EA.

Hemodynamics and Clinical Implications of Occult Left Ventricular Dysfunction in Adults Undergoing Ebstein Anomaly Repair.

BACKGROUND: Left ventricular global longitudinal strain (LVGLS) can detect early phases of LV systolic dysfunction, but its application has not been studied in Ebstein anomaly. We hypothesized that LVGLS can detect early phases of LV systolic dysfunction and that patients with occult LV systolic dysfunction will have worse hemodynamics, end-organ dysfunction, and suboptimal postoperative LV reverse remodeling after tricuspid valve surgery in comparison to patients with normal LV systolic function. METHODS: In this retrospective cohort study, 371 Ebstein patients that underwent tricuspid valve surgery were divided into 3 groups: normal LV systolic function (normal LVGLS and LV ejection fraction; n=244, 77%), occult LV systolic dysfunction (abnormal LVGLS with normal LV ejection fraction; n=44, 14%), and overt LV systolic dysfunction (abnormal LVGLS and LV ejection fraction; n=27, 9%). RESULTS: Compared with the normal LV function group, the occult group had smaller LV volume and cardiac output (2.1±0.4 versus 2.9±0.6 L/min per m2, P<0.001), worse end-organ dysfunction (glomerular filtration rate, 78±14 versus 91±18 mL/min per 1.73 m2, P=0.01), and suboptimal postoperative LV reverse remodeling. Although both the occult and overt groups had a similar degree of end-organ dysfunction (glomerular filtration rate, 78±14 versus 82±16 mL/min per 1.73 m2, P=0.3), the occult group was less likely to be on heart failure therapy (48% versus 96%, P<0.001). CONCLUSIONS: Abnormal LVGLS was associated with suboptimal postoperative LV reverse remodeling. These data suggest that LVGLS can potentially be used for risk stratification and provides a foundation for further studies to determine whether optimal heart failure therapy or tricuspid valve intervention can improve outcomes for LV systolic dysfunction in patients with Ebstein anomaly.

Cone reconstruction for Ebstein anomaly: Late biventricular function and possible remodeling.

OBJECTIVES: To evaluate late-term tricuspid valve competence and biventricular function following cone reconstruction for Ebstein anomaly, and to explore biventricular remodeling. METHODS: Consecutive adult and pediatric patients who underwent cone reconstruction from 2009 to 2019 were reviewed for inclusion in this retrospective cardiac magnetic resonance imaging study. Tricuspid valve competence was assessed with tricuspid regurgitation fraction. Biventricular systolic function was assessed by ejection fraction, cardiac index, indexed stroke volume, and indexed aortic and pulmonary artery beat volume. Biventricular remodeling was assessed by planimetered areas (right atrium, functional right ventricle, left heart), and indexed end-diastolic and end-systolic ventricular volumes. Paired t tests or Wilcoxon signed-rank tests were used for analyses. RESULTS: Of 58 included patients, 50 underwent cardiac magnetic resonance imaging. Twelve patients had both preoperative and late postoperative cardiac magnetic resonance imaging with a median follow-up of 5.11 years (interquartile range, 3.12-6.07 years). Focusing on these, tricuspid regurgitation fraction decreased (from 69% to 10%; P = .014), right ventricle ejection fraction remained stable, and antegrade pulmonary artery beat volume increased (from 26.7 to 41.6 mL/beat/m2; P = .037). The left ventricle stroke volume (from 30.4 to 44.1 mL/m2; P = .015) and antegrade aortic beat volume (from 28.5 to 41.1 mL/beat/m2; P = .014) also increased, and the left ventricle stroke volume improved progressively with time since surgery (P = .048). Whereas the right atrium area decreased (P = .004), the functional right ventricle and left heart area increased (cm2, P = .021 and P = .004). Right ventricle volumes showed a tendency to normalize and left ventricle indexed end-diastolic volume increased (from 50 to 69 mL/m2; P = .03) over time. CONCLUSIONS: Cone valve integrity was sustained. Biventricular function improved progressively during follow-up, and there are positive signs of biventricular remodeling late after cone reconstruction.

Effect of In Utero Non-Steroidal Anti-Inflammatory Drug Therapy for Severe Ebstein Anomaly or Tricuspid Valve Dysplasia (NSAID Therapy for Fetal Ebstein anomaly).

Ebstein anomaly (EA) and tricuspid valve dysplasia (TVD) are rare congenital malformations associated with nearly 50% mortality when diagnosed in utero. The diseases often produce severe tricuspid regurgitation (TR) in the fetus and in some cases, pulmonary regurgitation (PR) and circular shunting ensue. Since the ductus arteriosus (DA) plays a critical role in the circular shunt and may be constricted by transplacental nonsteroidal anti-inflammatory drugs (NSAIDs), we sought to assess the effect of NSAIDs on fetuses with EA/TVD. We reviewed mothers of singleton fetuses with EA/TVD and PR, indicative of circular shunting, who were offered NSAIDs at multiple centers from 2010 to 2018. Initial dosing consisted of indomethacin, followed by ibuprofen in most cases. Twenty-one patients at 10 centers were offered therapy at a median gestational age (GA) of 30.0 weeks (range: 20.9 to 34.9). Most (15/21 = 71%) mothers received NSAIDs, and 12 of 15 (80%) achieved DA constriction after a median of 2.0 days (1.0 to 6.0). All fetuses with DA constriction had improved PR; 92% had improved Doppler patterns. Median GA at pregnancy outcome (live-birth or fetal demise) was 36.1 weeks (30.7 to 39.0) in fetuses with DA constriction versus 33 weeks (23.3 to 37.3) in fetuses who did not receive NSAIDs or achieve DA constriction (p = 0.040). Eleven of 12 patients (92%) with DA constriction survived to live-birth, whereas 4 of 9 patients (44%) who did not receive NSAIDs or achieve DA constriction survived (p = 0.046). In conclusion, our findings demonstrate the proof of concept that NSAIDs mitigate circular shunt physiology by DA constriction and improve PR among fetuses with severe EA/TVD. Although the early results are encouraging, further investigation is necessary to determine safety and efficacy.

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.

Prognostic Role of Hepatorenal Function Indexes in Patients With Ebstein Anomaly.

BACKGROUND: Hepatorenal dysfunction is a risk factor for mortality in patients with chronic tricuspid regurgitation due to acquired heart disease. Ebstein anomaly is the most common cause of primary tricuspid regurgitation in adults with congenital heart disease, but the prevalence and prognostic implications of hepatorenal dysfunction are unknown in this population. OBJECTIVES: The purpose of this study was to determine the risk factors and prognostic implications of hepatorenal dysfunction, as measured primarily by the use of model for end-stage liver disease excluding international normalized ratio (MELD-XI score), as well as looking at other associated factors. METHODS: This was a retrospective study of adults with Ebstein anomaly who received care at Mayo Clinic from 2003 to 2018. RESULTS: Of 692 patients, the median MELD-XI score was 10.2 (interquartile range: 9.4 to 13.3); 53 (8%) died and 3 (0.4%) underwent heart transplant. MELD-XI was an independent predictor of death/transplant (hazard ratio: 1.32; 95% confidence interval: 1.11 to 2.06; p < 0.001). In the subset of patients with serial MELD-XI scores (n = 416), temporal change in MELD-XI score (ΔMELD-XI) was also a predictor of death/transplant. In the subset of patients who underwent tricuspid valve surgery (n = 344), a post-operative improvement in MELD-XI score (ΔMELD-XI) was associated with improved long-term survival. Impaired right atrial (RA) reservoir strain and elevated estimated RA pressure were associated with worse baseline MELD-XI and ΔMELD-XI scores. CONCLUSIONS: Hepatorenal dysfunction is a predictor of mortality in Ebstein anomaly, and RA dysfunction and hypertension are hemodynamic biomarkers that can identify patients at risk for deterioration in hepatorenal function and mortality. These data highlight the prognostic importance of noncardiac organ-system dysfunction, and provide complementary clinical risk stratification metrics for management of these patients.

Strain and Strain Rate To Evaluate Right Heart Function of Ebstein Anomaly (EA) Patients Before and After Operation.

OBJECTIVE: This study was aimed to elucidate the feasibility of using right ventricular (RV) strain and strain rate to evaluate right heart function of Ebstein anomaly (EA) patients before and after operation. METHODS: Sixty EA patients and 30 healthy controls underwent echocardiography (UCG) for evaluation of right heart function. Preoperative UCG and 1-week and 3-month postoperative UCG were performed in EA patients. RV strain and strain rate were measured on the four-chamber section of tissue Doppler imaging (TDI). RESULTS: The strain and strain rate representative of right ventricle systolic function were reduced prior to operation. RV strain and strain rate improved after the operation (P < .001), most significantly in the basal segment and middle segment of the free wall of the right ventricle as well as the basal segment of the interventricular septum (P < .001). CONCLUSIONS: The measurement of RV strain and strain rate on tissue Doppler imaging can be employed to assess the preoperative and postoperative RV function, proves the positive effect of tricuspid valve repair on right heart function, and offers more insight on right heart function evaluation.

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.

Ebstein anomaly associated with cri du chat (cat's cry) syndrome and 20q duplication.

Ebstein anomaly is a congenital heart defect with a low prevalence and high mortality in the early stages of life. In medical literature, there is no reported association between Ebstein anomaly and cri du chat syndrome. Here, we report the case of a full-term newborn with a low weight for his age and who had a prenatal diagnosis of Ebstein anomaly and a postnatal diagnosis of cri du chat syndrome and 20q duplication detected on array CGH. The patient required medical treatment with inotropic support, high-frequency ventilation and nitric oxide, with an adequate response. Surgical intervention was not needed.

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.

Permanent Pacing in a Patient With Fontan Circulation: Use All You Have at Your Discretion.

Patients with Fontan circulation post significant technical challenges at the time of permanent pacemaker implantation, as majority of them are treated with surgically implanted epicardial pacemakers. However, transvenous pacemaker implantation is technically feasible, and the treating physician should be aware of each individual's anatomy and available treatment options.

Cone repair for Ebstein's anomaly and atrial fibrillation ablation in an adult patient.

We present a 52-year-old woman with Ebstein's anomaly not previously treated. In this subset of patients, there are no clear guidelines regarding the best surgical strategy for treating the tricuspid valve: replace it or repair it.  In this case, extensive repair of the tricuspid valve and the right ventricle is achieved using the cone repair technique popularized by Dr. José Pedro Da Silva. Because the patient also presented with symptomatic paroxysmal atrial fibrillation, a right atrial maze procedure combined with isolation of the pulmonary veins was performed using both radiofrequency and cryotherapy. At the last follow-up, 2 years after the repair, the patient is asymptomatic and maintains sinus rhythm. The last echocardiogram showed mild tricuspid regurgitation with normal right ventricular function.

Current and future role of fetal cardiovascular MRI in the setting of fetal cardiac interventions.

Over recent years, technical developments resulting in the feasibility of fetal cardiovascular magnetic resonance (CMR) have provided a new diagnostic tool for studying the human fetal heart and circulation. During the same period, we have witnessed the arrival of several minimally invasive fetal cardiac interventions (FCI) as a possible form of treatment in selected congenital heart diseases (CHDs). The role of fetal CMR in the planning and monitoring of FCI is not yet clear. Indeed, high-quality fetal CMR is not available or routinely offered at most centers caring for patients with prenatally detected CHD. However, in theory, fetal CMR could have much to offer in the setting of FCI by providing complementary anatomic and physiologic information relating to the specific intervention under consideration. Similarly, fetal CMR may be useful as an alternative imaging modality when ultrasound is hampered by technical limitations, for example, in the setting of oligohydramnios and in late gestation. In this review, we summarize current experience of the use of fetal CMR in the diagnosis and monitoring of fetuses with cardiopathies in the setting of a range of invasive in utero cardiac and vascular interventions and medical treatments and speculate about future directions for this versatile imaging medium.

Severity Scores for Ebstein Anomaly: Credibility and Usefulness of Echocardiographic vs Magnetic Resonance Assessments of the Celermajer Index.

BACKGROUND: The severity score of Ebstein anomaly (EA) that corresponds to clinical status is still under research, with the Celermajer index (Cel-ind) being one of those. The agreement between echocardiographic and cardiac magnetic resonance (CMR) assessment of Cel-ind is not known. We determined the agreement between echocardiography- and CMR-derived Cel-ind and its relationship with heart failure markers. METHODS: A total of 37 unoperated adults with EA (mean age, 43.0 ± 14.4 years) underwent echocardiography, CMR, and cardiopulmonary tests. For the Cel-ind, end-diastolic areas in echocardiography or end-diastolic volumes in CMR were used according to the following formula: Cel-ind = (right atrium + atrialized right ventricle)/(functional right ventricle + left atrium + left ventricle). On the basis of this assumption, patients were classified as follows: grade 1 = Cel-ind < 0.5, grade 2 = 0.5 to 0.99, grade 3 = 1.0 to 1.49, grade 4 > 1.5. The agreement between echocardiographic and CMR was determined with the intraclass correlation coefficient or Cohen's kappa (<0.2 poor agreement; 0.2-0.4 fair agreement; 0.4-0.6 moderate agreement; 0.6-0.8 good agreement; 0.8-1.0 very good agreement). RESULTS: The median echoCel-ind was 0.9 (range, 0.4-2.3), and the median cmrCel-ind was 0.7 (range, 0.3-5.3). Grade 1 or 2 was found in 19 patients (51.3%) by echocardiography and in 27 patients (72.9%) by CMR. The agreement between imaging methods was only fair (kappa = 0.39, P = 0.002) for the 4-grade classification and moderate (intra-class correlation coefficient = 0.43; 95% confidence interval, 0.13-0.66) for Cel-ind calculation. Significant correlations between Cel-ind in CMR and cardiopulmonary parameters were found (for peak oxygen uptake: R = -0.35, P = 0.034; for the ventilation/carbon dioxide slope: R = 0.46, P = 0.005). Neither of them correlated with echocardiographic severity score. CONCLUSIONS: The agreement between echocardiographic and CMR assessment of the Cel-ind is at most moderate; echocardiography usually overestimates, but rarely underestimates, EA severity. Cel-ind by CMR seems to be more valuable, because it is associated with heart failure markers.

Right Ventricular Diastolic Function and Right Atrial Function and Their Relation With Exercise Capacity in Ebstein Anomaly.

BACKGROUND: Right ventricular (RV) diastolic function and right atrial (RA) function are poorly characterized in patients with Ebstein anomaly (EA) but may influence functional capacity. We aimed to evaluate RV diastolic function and RA function in EA and study their relationship with biventricular systolic function and exercise capacity. METHODS: Seventy-two patients with EA and 69 controls prospectively underwent echocardiography, cardiovascular magnetic resonance imaging, and cardiopulmonary exercise testing to investigate RV systolic and diastolic function, RA function, and exercise capacity. RESULTS: Altered RV diastolic function was indicated by the reduced tricuspid valve E/A ratio, percentage RV filling time, and early and late diastolic strain rate; and by the increased tricuspid valve E/E', isovolumic relaxation time, and RV myocardial performance index. The average of 6-RV-segment early diastolic strain rate correlated modestly with peak VO2 (r = 0.38, P < 0.01), RV ejection fraction (r = 0.41, P < 0.01), and left ventricular ejection fraction (r = 0.33, P < 0.05). Patients with EA had impaired RA reservoir, conduit, and pump function, which were associated with peak VO2 (r = 0.54, P < 0.001 for reservoir function). CONCLUSIONS: Altered RV diastolic function and RA function in patients with EA are associated with impaired biventricular systolic function and exercise capacity. The stronger correlation of RA vs RV function with exercise capacity suggests that it may be important to evaluate RA function in this population.

Quantitative Assessment of Left Ventricular Dysfunction in Fetal Ebstein's Anomaly and Tricuspid Valve Dysplasia.

BACKGROUND: Fetal Ebstein's anomaly and tricuspid valve dysplasia (EA/TVD) are associated with high perinatal mortality relative to pulmonary atresia with intact ventricular septum (PAIVS), despite both requiring redistribution of the cardiac output (CO) to the left ventricle (LV). LV dysfunction is suspected to contribute to adverse outcomes in EA/TVD. OBJECTIVE: We sought to examine global and segmental LV function in fetal EA/TVD with comparison to normal controls and PAIVS. We hypothesized that LV dysfunction in EA/TVD is associated with abnormal LV remodeling and interventricular mechanics. METHODS: We retrospectively identified 63 cases of fetal EA/TVD (40 with retrograde ductal flow) and 22 cases of PAIVS encountered from 2004 to 2015 and compared findings to 77 controls of comparable gestational age. We measured the combined CO and global LV function using two-dimensional, Doppler-derived, deformational (six-segmental vector velocity imaging) and dyssynchrony indices (DIs; SD of time to peak), and a novel global DI. RESULTS: EA/TVD fetuses demonstrated abnormal LV global systolic function with reduced ejection fraction, fractional area change, and CO, while in PAIVS we observed a normal ejection fraction, fractional area change, and CO. PAIVS, but not EA/TVD, demonstrated increased LV sphericity, suggestive of remodeling, and associated enhanced radial function in the third trimester. In contrast, while EA/TVD fetuses had normal LV segmental longitudinal strain, there was abnormal radial segmental deformation and LV dyssynchrony with increased SD of time to peak and DI. CONCLUSIONS: Fetal EA/TVD is associated with a lack of spherical remodeling and presence of mechanical dyssynchrony, which likely contribute to reduced CO and ejection fraction. Clinical monitoring of LV function is warranted in fetal EA/TVD. Further studies incorporating quantification of LV function into prediction models for adverse outcomes are required.

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.

Postoperative persistent diastolic dyssynchronous expansion in patients with Ebstein's anomaly.

In Ebstein's anomaly, maximal expansion in the atrialized right ventricle (RV) occurs during early diastole, whereas that of the functional RV occurs in late diastole, resulting in diastolic dyssynchronous expansion (DSE). We quantitatively assessed DSE and identified preoperative factors correlated with persistent DSE after surgery. Seventeen patients diagnosed with Ebstein's anomaly in whom transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) images available were retrospectively analyzed for quantitative DSE assessment and 10 patients who underwent surgery and postoperative TTE available were additionally analyzed for postoperative DSE. Severity of DSE was assessed by the time difference of maximal expansion between the atrialized and functional RV divided by the cardiac cycle length × 100 ("DSE index"). Relations between DSE and, clinical, electrophysiologic parameters and the severity of tricuspid valve (TV) tethering (the RV length / tethering height during diastole: "Tethering index") were assessed. In total patients, median DSE index and tethering index were 30.3 and 2.1 respectively, and the DSE index was correlated with tethering index (rs = 0.664, P = 0.004). In 10 patients who underwent surgery, this association remained after surgery and at 2-year follow up. Tethering index ≥2.5 separated patients with and without persistent DSE. In conclusion, DSE exists in Ebstein's anomaly. DSE index is related to the tethering index and DSE persists postoperatively if tethering index ≥ 2.5. As the persistent DSE might possibly impede the optimal recovery of RV function after surgery, severity of TV tethering should take into account in considering surgery.