Abstract 16010: Sudden Death in the Systemic Right Ventricle: Single Center Study of Dextro-Transposition of the Great Arteries Palliated With Atrial Switch

Abstract

Introduction: The incidence and risk factors for sudden cardiac death (SCD) in patients with systemic right ventricle (sRV) and D-TGA palliated with atrial switch procedures is not well understood. Methods: This cohort was examined retrospectively for the composite end point of SCD, sustained ventricular tachycardia (VT) >30 s or appropriate ICD therapy for VT. Clinical characteristics of those with and without the end point were compared using the Kruskal-Wallis or Chi-square test as appropriate. Results: The composite end point occurred in 15 of 148 (10%) patients (63.5% male) at a mean age of 36.4 (SD 10.3) years. SCD occurred in 6 patients (n=2 successfully resuscitated), sustained VT in 6 patients and ICD therapy for VT in 3 patients who had previously received a primary prevention ICD. Patients with SCD/VT had lower sRV ejection fraction (EF) compared to patients without SCD/VT [28±11 vs 40±10%, P<0.001]. The odds ratio of SCD/VT in patients with sRVEF≤35% compared to sRVEF>35% was 13.3 (95% CI 2.8 - 64.4). Kaplan Meier analysis of time to SCD/VT stratified by sRV EF is presented in figure. QRS duration, QRS fragmentation, QTc and history of systemic AV valve surgery were not significantly associated with SCD/VT. Non-sustained ventricular tachycardia (NSVT) on Holter monitoring occurred more frequently in SCD/VT patients (80 vs 39%, p=0.003). All 11 survivors of SCD/VT received an ICD; appropriate ICD therapy occurred in 27% of these patients during follow-up. Conclusion: SCD or VT occurred in one-tenth of D-TGA patients palliated with atrial switch, predominantly in 3 rd and 4 th decade of life. Reduced sRV EF was the most important association and ICD implantation for primary prevention of SCD is a reasonable consideration in those with reduced sRV EF.