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

Abstract

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

Keywords: Arrhythmias, Cardiac; Congenital Abnormalities; Diagnostic Imaging; Genetics; Heart Defects, Congenital.

Figure 1

Magnetic resonance cine-SSFP images in a patient with Ebstein’s anomaly in short axis (A, B) and long axis (C, D) views at end-diastole, highlighting the orientation of each cine-SSFP slice. Focusing on the tricuspid valve, apical displacement of the septal leaflet and rotation angle are reported in horizontal long-axis (C) and vertical long-axis views (D), respectively. RV, right ventricle; SSFP, steady-state free precession .

Figure 2

Cone repair assessed through multimodality imaging during diastole (A): vertical long axis view of cine-SSFP sequence from CMR imaging and en face view by 3D-TOE (ventricular perspective). White arrows indicate the cone-shaped valve. (B) Structural complications of cone repair, as highlighted by a white arrow: (I) en face neo valve view with dehiscence of the antero-septal region by colour flow Doppler 3D-TOE; (II) phase-sensitive inversion recovery reconstruction (PSIR) sequence of a mid-ventricular short-axis view, showing myocardial infarction in the territory supplied by the right coronary artery, as represented by transmural late gadolinium enhancement of the inferior wall, inferior septum and RV diaphragmatic wall; (III) cine-SSFP mid-ventricular short-axis view of right ventricular plication dehiscence; (V) colour flow Doppler 2D TTE of neo-subvalvular acceleration in a four-chamber view. CMR and TTE images are courtesy of Boston Children’s Hospital, Department of Cardiology. CMR, cardiovascular magnetic resonance; 3D-TOE, three-dimensional transesophageal echocardiography; RV, right ventricle; SSFP, steady-state free precession; TTE, transthoracic echocardiography.

Figure 3

Classification of Ebstein’s anomaly from imaging. For the quantitative indexes, each term of the formula is highlighted in yellow when it is part of the numerator and in red when it is part of the denominator. AL, anterior leaflet; aRV, atrialised right ventricle; CMR, cardiac magnetic resonance; fRV, functional right ventricle; LA, left atrium; LV, left ventricle; PL, posterior leaflet; RA, right atrium; RV, right ventricle; SL, septal leaflet; TTE, transthoracic echocardiography.

Figure 4

Main transthoracic echocardiographic views in EA. PLAX view was acquired with inferior tilt of the probe from conventional PLAX window. Right oblique subxifoid view was acquired with counterclockwise rotation of the transducer head from the four-chamber view. 4CH, four-chamber view; Ao, aorta; AL, anterior leaflet; aRV, atrialised right ventricle; ASD, atrial septal defect; CS, coronary sinus; EA, Ebstein’s anomaly; fRV, functional right ventricle; FW, free wall; IAS, interatrial septum; IVS, interventricular septum; LA, left atrium; LV, left ventricle; Pas, pulmonary arteries; PL, posterior leaflet; PLAX, parasternal long-axis view; PSAX, parasternal short-axis view; RA, right atrium; RVOT, right ventricular outflow tract; SL, septal leaflet; TV, tricuspid valve leaflets.

Figure 5

Clinical manifestations and pathophysiological substrates of Ebstein’s anomaly. The interplay between arrhythmias and heart failure is highlighted. RA dilation promotes the occurrence of intra-atrial re-entries and the presence of accessory pathways may be the substrate for atrioventricular re-entries; aRV is vulnerable to trigger ventricular arrhythmias. Fast-conduced arrhythmias may contribute to ventricular dysfunction and reduced filling time. Adverse myocardial remodelling may enhance the arrhythmic substrate. Increased RA pressures favour right-to-left shunt in the presence of atrial communications, thus worsening hypoxia. Systemic embolisation is favoured by occurrence of atrial fibrillation or paradoxical thrombosis. Ao, aorta; ARV, anatomical right ventricle; aRV, atrialised right ventricle; LA, left atrium; L-R, left to right; LV, left ventricle; PA, pulmonary artery; R-L, right to left; RA, right atrium.

Figure 6

Structural and functional cardiac alterations in Ebstein’s anomaly (A) and changes after cone repair surgery (B). Also, a cine SSFP CMR sequence (horizontal long-axis view at end-diastole) is reported in the same patient before (A) and after cone repair (B). Ao, aorta; aRV, atrialised right ventricle; CMR, cardiovascular magnetic resonance; fRV, functional right ventricle; fSV, forward stroke volume; IVS, interventricular septum; LA, left atrium; LV, left ventricle; PA, pulmonary artery; RA, right atrium; RV, right ventricle; SSFP, steady-state free precession; TR, tricuspid regurgitation.

Figure 7

Possible outcome modifiers and monitoring strategy for the key clinical manifestations of Ebstein’ anomaly, namely heart failure, arrhythmias and cyanosis. BNP, brain-natriuretic peptide; CPET, cardiopulmonary exercise test; EPS, electrophysiological study; Hb, haemoglobin; Hct, haematocrit; IAC, interatrial communication; NYHA, New York Heart Association class; O2, oxygen; spO2, peripheral oxygen saturation; TR, tricuspid regurgitation; VE/VCO2, minute ventilation/carbon dioxide production; VO2, oxygen consumption; WPW, Wolf-Parkinson-White pattern.

Figure 8

Cone repair surgery is realised through a median sternotomy in cardiopulmonary by-pass with standard aortic and bicaval cannulation, left vent and cardioplegic cardiac arrest. After careful inspection and marking of the coronary arteries’ anatomy (A), transverse RA incision is performed in the direction of the cavotricuspid isthmus. After a complete detachment and mobilisation of the delamination defects (B), part of the aRV is plicated or resected (C), and the neo valve, generally slightly rotated clockwise, is sutured into the anatomical annulus (D). The result is a cone-shaped valve with the vertex fixed at the RV apex (E); the valve is tested for competency (F), and then, if needed, stabilised with ring annuloplasty (G). RA, right atrium; RV, right ventricle.