Abstract 17846: Temporal Shift Towards Left Ventricular Sources of Idiopathic Ventricular Ectopy in Patients Referred for Ablation

IntroductionHistorically the focus of ectopy in idiopathic ventricular tachycardia (VT) or premature ventricular contractions (PVC) showed a heavy bias towards right ventricular origins. The purpose of this study is to characterize the incidence of right vs left ventricular origins of idiopathic VT/PVC in patients referred for ablation in a modern cohort of patients.HypothesisThere has been a temporal shift towards more left ventricular locations in patients who present for idiopathic VT/PVC ablation.MethodsThe study population includes all patients referred for VT or PVC ablation at two sites within the Yale-New Haven Health System from January 1, 2011 to June 30, 2015. Patients were excluded if there was a history of cardiomyopathy or other structural heart disease. For each patient, clinical characteristics, medical history, ECGs, cardiac imaging, stress testing and Holter monitors were reviewed. Operative reports from the ablation procedure were reviewed. Location of the VT/PVC was defined as the site where ablation resulted in termination of the arrhythmia.ResultsThere were 67 cases included in the final analysis. There were no significant differences in baseline patient characteristics such as age, gender or body mass index between right and left ventricular locations. Right vs left ventricular location for the first vs second half of the time period are summarized in the figure. In the first half of the time period there was 95% vs 5% for right and left ventricular location respectively. In the second half there was 59% vs 41% for right vs left ventricular location respectively. (p=0.003)ConclusionsThere has been a shift over time toward more left ventricular locations for idiopathic VT/PVC that present for ablation. No risk factors were identified that may contribute to this change. Confounders such as referral bias, environmental factors or improved recognition of left sided foci at ablation may contribute to this change and deserves further study.