Vectorcardiographic predictors of ventricular arrhythmia inducibility in patients with tetralogy of Fallot

Introduction: Vectorcardiography (VCG) may have predictive value in Tetralogy of Fallot (TOF) patients undergoing ventricular arrhythmia inducibility (VAI) electrophysiology studies (EPs). Materials and methods: Blinded, retrospective analyses of 37 adult TOF patients undergoing EPs prior to pulmonary valve replacements were performed (21 female, median age 37 years). VAI was evaluated from EPs and resting 12-lead electrocardiograms, respectively using QRS and heart rate adjusted Q-T intervals, spatial QRS-T angles (peaks), T-wave and QRS-wave (QRSwave vc) component vector root mean squares. Differences were assessed (Student t-tests, Mann Whitney U-tests, Analysis of Variance). Relative risks were calculated. Results: 16 patients had VAI (6 monomorphic, 10 polymorphic). Only the QRSwave vc showed significant differences between those with and without VAT, 10.5 +/- 2.4 dmV vs. 13.9 +/- 4.5 dmV, respectively (p = 0.002), area under the ROC curve of 0.78 and relative risk of 2.52. Conclusion: VCG evidence of depolarization differences was significant between TOF patients with and without inducible VA. (C) 2015 Elsevier Inc. All rights reserved.