Assessing left ventricular pathology in patients with Ebstein anomaly using Cardiovascular magnetic resonance: Looking past the right heart

Abstract Background: Ebstein Anomaly (EA) is a malformation of the right heart, but there is data to suggest that the left ventricle (LV) can suffer from intrinsic structural and functional abnormalities which affect surgical outcomes. Hypothesis: The LV in patients with EA is hypertrabeculated with abnormalities in LV function and strain. Methods: In this retrospective single-center study, patients with EA who underwent pre-operative cardiac MRI (CMR) between the period of 2014-2023 were included along with a group of healthy-age-matched controls. Left ventricular and right ventricular volume, function and strain analyses were performed on standard SSFP imaging. LV noncompacted:compacted (NC/C) ratio and the displacement index of the tricuspid valve were measured. Results: Thirty-five EA patients were included with mean age of 21.0 +/- 16.4 years. Thirteen EA patients (37%) had mild pre-operative LV dysfunction on CMR and 1 (3%) had moderate LV dysfunction. The global circumferential and longitudinal strain were significantly lower in the reduced LVEF group compared to those with preserved LVEF (-15% vs. -16.8%, p =0.01 and −11.8% vs. −16.1%; p =0.04; respectively). A single EA patient (3%) met criteria for LVNC with a maximal NC/C ratio > 2.3. There was no statistically significant difference in NC/C ratio in the EA population (1.33 +/- 0.5) vs. controls (1.11 +/- 0.2), p = 0.16. There was an inverse correlation of LV ejection fraction (EF) with right ventricular end-diastolic volume and displacement index (DI). All patients underwent the Da Silva Cone procedure at our center. Patients with preoperative LV dysfunction had longer bypass time (163 +/- 42 vs 142 +/-38 min, p=0.17) and duration of postoperative epinephrine support (23.5 +/- 22 vs 11.2 +/- 22.3 hours, p=0.20). Conclusions: This is the largest study to date to evaluate preoperative LV structure and function in EA patients by CMR. In this cohort of 35 patients, LV non-compaction was rare, though there was a trend toward increased trabeculation. Pre-operative LV dysfunction is common and associated with more severe EA with larger RV size. The presence of LV dysfunction is relevant to perioperative management and further study with larger cohorts and longer follow up are necessary.