Abstract 15314: Left Ventricular Dysfunction in Children and Adolescents With Arrhythmogenic Right Ventricular Cardiomyopathy

Abstract

Background: Involvement of the left ventricle (LV) is increasingly recognized in adults with arrhythmogenic right ventricular cardiomyopathy (ARVC) but it is unclear whether LV function is compromised in children with this condition. The aim of this study was examine myocardial contractility in pediatric patients with suspected ARVC. Methods: For this retrospective study, patients with a work-up for ARVC were classified into ‘no’, ‘possible’, ‘borderline’ or ‘definite’ ARVC according to the revised Task Force Criteria (rTFC). Ventricular size and function as well as LV myocardial strain and torsion were measured by cardiac magnetic resonance (CMR). Results: A total of 142 patients were enrolled, of whom 58 (41%) had no, 32 (23%) possible, 29 (20%) borderline and 23 (16%) definite ARVC. The groups were similar in age at CMR. With higher rTFC score, z scores (Z) of right ventricular (RV) ejection fraction (EF) were lower (p<0.001) while z-RV end diastolic volume (EDV) and z-LV EDV were larger (p=0.002 and 0.013, respectively). LV EF did not differ between rTFC categories. Global circumferential strain (GCS) of the LV was lower in patients in higher rTFC categories (p=0.018). Z-LVEDV correlated with z-RVEDV (r2 = 0.69, p<0.001) and z- LVEF correlated with z-RVEF (r2 = 0.55, p <0.001). Z-LVEF and z-RVEF correlated with LV GCS (r2 = 0.48, p<0.001 and r2 = 0.46, p<0.001, respectively) and torsion (r2 = 0.21, p=0.032 for both). Forty-two patients had a follow-up CMR, after a median interval of 2.6 years (0.4- 8.4). The rate of deterioration of LV or RV EF or EDV did not differ between rTFC categories. A more rapid increase of z-RVEDV was associated with a faster decline in z-RVEF (r2 = -0.383, p=0.004) and z-LVEF (r2 = -0.45, p=0.001). A decline of z-LVEF over time correlated with that of z-RVEF (r2 = 0.60, p<0.001) and z-LVEDV increase correlated with z-RVEDV increase (r2 = 0.84, p<0.001). Conclusion: LV myocardial dysfunction is present in young patients with suspected or confirmed ARVC. Quantification of myocardial mechanics with CMR may be a useful tool to detect early LV involvement in ARVC. Progressive LV dysfunction and enlargement appear to parallel those of the RV.