Abstract 1975: Right Ventricular Dysfunction is a Risk Factor for Ventricular Tachyarrhythmia and Sudden Death in Congenitally Corrected Transposition of the Great Arteries
Introduction Left ventricular (LV) failure (ejection fraction (EF)<35%) is associated with an increased risk of sudden death due to ventricular tachyarrhythmia (VT/VF). However, whether or not right ventricular (RV) failure is also associated with increased risk of sudden death is unclear. We sought to further clarify this risk in patients (pts) with congenitally corrected transposition of the great arteries (ccTGA).
Methods Clinical information, including echocardiograms, demographics, and MRIs from 131 pts followed for ccTGA was reviewed. All pts were contacted to obtain current clinical status. Data including ICD discharges, incidence of VT/VF, and cause of death were obtained.
Results Pts (n=131) were followed for an average 5.9 years with average systemic RV (SRV) EF 39% (n=56, EF<35%) and average non-systemic LV EF 54% (n=2, EF<35%). Of 56 pts with SRV EF<35%, 10 died at an average age of 51, 3 from documented VF, 1 from heart failure (HF), and 6 suddenly. Of 75 pts with SRV EF>35%, 8 died at an average age of 63, 2 from non-arrhythmic cardiac causes (HF, MI), 1 suddenly, and 5 from non-cardiac causes. There was no significant difference in age at death, death from documented arrhythmia, or death from all cause between pts with SRV EF<35% and >35%. However, risk of sudden death was higher in pts with SRV EF<35% (16% vs 1%, p=0.0021). Significant arrhythmia (sustained VT requiring defibrillation or cardiac arrest due to VT/VF) occurred in 13/56 pts (23%) with SRV EF<35% compared with 2/75 (3%) with SRV EF>35% (p<0.001). ICDs were placed in 17 pts (30%) with SRV EF<35%; 9 for documented VT/VF, 2 for syncope and documented >5 beat NSVT, 1 for MADIT2 criteria. Three (18%) pts with ICD and SRV EF<35% had appropriate shock for VT/VF (2 with prior VT/VF, 1 for primary prevention). Three pts with SRV EF>35% had ICDs placed (2 for prior VT/VF) but none had shocks from their device. The combined clinical endpoint of ICD shock, clinically significant VT/VF, and sudden death was significantly higher in pts with SRV EF<35% than in pts with SRV EF>35%, independent of the presence of LV EF<35%. (p<0.001).
Conclusions Dysfunction of a systemic RV increases risk of sudden death and clinically significant ventricular tachyarrhythmias in ccTGA.