Left Ventricular Pathology in Ebstein’s Anomaly—Myocardium in Motion

bstein's anomaly (EA) of the tricuspid valve is a rare congenital cardiac malformation accounting for only 0.5% of all congenital heart disease.It comprises a dysplastic tricuspid valve offset towards the apex, an atrialization of the right ventricle and tricuspid regurgitation.Progressive right heart failure and impaired physical exercise capacity occur in many patients with EA at some stage in their life, which are predominantly associated with abnormal right heart function and morphology.However, left ventricular (LV) alterations appear to be involved in heart failure in EA, as well. 1 The left heart has been subject of much less attention as compared with the right heart in EA.Nevertheless, previous studies demonstrated impaired deformation of the LV, 2 including the septum 1 and the left atrium 3 as well as LV dyssynchrony.4,5 All of the latter were also associated with heart failure markers, which suggests direct implications on the clinical course.Cone repair of the tricuspid valve seems to be an effective treatment and evidence suggests that the beneficial effects may be also based on improved basal septal deformation and synchrony of the LV, as detected by cardiovascular magnetic resonance (CMR) 6 or echocardiography.7 Since the surgical treatment option is mainly reserved for severe or later stages of the disease a better understanding of early pathophysiological mechanisms with a potential for preventive actions is highly desirable.However, the pathogen on a tissue level that may underlie these early alterations especially in LV function and later deterioration of overall cardiac function is still unknown.The study by Aly et al 8 published in this issue of Circulation Cardiovascular Imaging helps to shed new light on this enigma in patients with EA by looking at markers of fibrosis and deformation.It touches on an interesting topic, the nature of LV dysfunction in unrepaired EA.The authors studied a group of 12 unrepaired pediatric patients with EA retrospectively with regard to CMR markers of fibrosis, strain and volumes, different severity indices and exercise capacity on cardiopulmonary exercise testing as well as oxygen saturation.The EA group is compared with a group of supposedly healthy controls who had undergone CMR for exclusion of chest pain or ARVC and had no phenotypic disease.Aly et al demonstrate the following new findings:1. Patients with EA exhibited higher LV T1 and extracellular volume values: (1026±47 versus 956±40 ms, P=0.0004 and 28.5±3.4% versus 22.5±2.6%,P<0.001, respectively).2. LV deformation parameters were decreased in patients with EA: circumferential strain and strain rate (-22±12% versus -27±14%, P<0.001 and 4.5±2.7%/sversus 6.5±3.2%/s,P<0.001, respectively) and radial strain and strain rate (39±19% versus 45±8%, P=0.003, and 9±5%/s versus 14±11%/s, P=0.01, respectively).